Nucleation of transition waves via collisions of elastic vector solitons

In this work, we show that collisions of one type of nonlinear wave can lead to generation of a different kind of nonlinear wave. Specifically, we demonstrate the formation of topological solitons (or transition waves) via collisions of elastic vector solitons, another type of nonlinear wave, in a multi-stable mechanical system with coupling between translational and rotational degrees of freedom. We experimentally observe the nucleation of a phase transformation arising from colliding waves, and we numerically investigate head-on and overtaking collisions of solitary waves with vectorial properties (i.e., elastic vector solitons). Unlike KdV-type solitons, which maintain their shape despite collisions, our system shows that collisions of two vector solitons can cause nucleation of a new phase via annihilation of the vector soltions, triggering the propagation of transition waves. The propagation of these depends both on the amount of energy carried by the vector solitons and on their respective rotational directions. The observation of the initiation of transition waves with collisions of vector solitons in multistable mechanical systems serves as an example of new fundamental nonlinear wave interactions, and could also prove useful in applications involving reconfigurable structures

Origami-based impact mitigation via rarefaction solitary wave creation

The principles underlying the art of origami paper folding can be applied to design sophisticated metamaterials with unique mechanical properties. By exploiting the flat crease patterns that determine the dynamic folding and unfolding motion of origami, we are able to design an origami-based metamaterial that can form rarefaction solitary waves. Our analytical, numerical and experimental results demonstrate that this rarefaction solitary wave overtakes initial compressive strain waves, thereby causing the latter part of the structure to feel tension first instead of compression. This counter-intuitive dynamic mechanism can be used to create a highly efficient--yet reusable--impact mitigating system without relying on material damping, plasticity or fracture

Relationship between Visual Acuity and Lifestyle: A Cross-Sectional Study in Japanese Children

Purpose: To evaluate poor visual acuity (PVA) prevalence and factors related to PVA, including parental myopia status and lifestyle, in primary school children. Methods: Of total 220 primary school children from grades 4–6 in Hiroshima, 184 (83.6%) were enrolled in the study. They were divided into non-PVA (both eyes’ acuities ≥ 1.0) and PVA (one or both eyes’ acuity < 1.0 and/or wearing spectacles) groups. Data on lifestyle activities were obtained using self-reported questionnaires regarding daily lifestyle, including the duration of watching TV, playing games, using a computer, studying, number of books read per month, and outdoor activities. Results: The total prevalence of PVA was 66.8%: 50.0% for grade 4, 71.4% for grade 5, and 74.6% for grade 6. In binary logistic regression models, children who had at least one parent with myopia showed greater PVA than those with parents without myopia (OR = 1.89; 95% CI, 1.14 to 3.15). In addition, weekend studying was significantly associated with PVA (OR = 1.48; 95% CI, 1.03 to 2.12), and the number of books read per month was associated with PVA (OR = 1.26, 95% CI, 1.05 to 1.51). Conclusions: This study confirmed a high PVA prevalence in primary school children, and that the rate of PVA increased with advancing grade. Parental myopia was associated with PVA, as were long studying time and a high number of books read per month

Isolated gestational proteinuria preceding the diagnosis of preeclampsia : an observational study

Introduction. Some pregnant women develop significant proteinuria in the absence of hypertension. However, clinical significance of isolated gestational proteinuria (IGP) is not well understood. This study aimed to determine the prevalence of IGP in singleton pregnancies and the proportion of women with IGP who subsequently developed preeclampsia (IGP-PE) among all PE cases. Material and methods. This was an observational study of 6819 women with singleton pregnancies at 12 centers, including 938 women with at least once determination of protein-to-creatinine ratio (P/Cr). Significant proteinuria in pregnancy (SPIP) was defined as P/Cr (mg/mg) level >0.27. IGP was defined as SPIP in the absence of hypertension. Gestational hypertension (GH) preceding preeclampsia (GH-PE) was defined as preeclampsia (PE) in which GH preceded SPIP. Simultaneous PE (S-PE) was defined as PE in which both SPIP and hypertension occurred simultaneously. Results. IGP and PE were diagnosed in 130 (1.9%) and 158 (2.3%) of 6819 women, respectively. Of 130 women with IGP, 32 (25%) progressed to PE and accounted for 20% of all women with PE. Hence, women with IGP had a relative risk of 13.1 (95% CI; 9.2-18.5) for developing PE compared with those without IGP [25% (32/130) vs. 1.9% (126/6689)]. At diagnosis of SPIP, P/Cr levels already exceeded 1.0 more often in women with S-PE than in those with IGP-PE [67% (33/49) vs. 44% (14/32), respectively, p = 0.031]. Conclusions. IGP is a risk factor for PE, and IGP-PE accounts for a considerable proportion (20%) of all PE

Dok-1 and Dok-2 are negative regulators of lipopolysaccharide-induced signaling

Endotoxin, a bacterial lipopolysaccharide (LPS), causes fatal septic shock via Toll-like receptor (TLR)4 on effector cells of innate immunity like macrophages, where it activates nuclear factor κB (NF-κB) and mitogen-activated protein (MAP) kinases to induce proinflammatory cytokines such as tumor necrosis factor (TNF)-α. Dok-1 and Dok-2 are adaptor proteins that negatively regulate Ras–Erk signaling downstream of protein tyrosine kinases (PTKs). Here, we demonstrate that LPS rapidly induced the tyrosine phosphorylation and adaptor function of these proteins. The stimulation with LPS of macrophages from mice lacking Dok-1 or Dok-2 induced elevated Erk activation, but not the other MAP kinases or NF-κB, resulting in hyperproduction of TNF-α and nitric oxide. Furthermore, the mutant mice showed hyperproduction of TNF-α and hypersensitivity to LPS. However, macrophages from these mutant mice reacted normally to other pathogenic molecules, CpG oligodeoxynucleotides, poly(I:C) ribonucleotides, or Pam3CSK4 lipopeptide, which activated cognate TLRs but induced no tyrosine phosphorylation of Dok-1 or Dok-2. Forced expression of either adaptor, but not a mutant having a Tyr/Phe substitution, in macrophages inhibited LPS-induced Erk activation and TNF-α production. Thus, Dok-1 and Dok-2 are essential negative regulators downstream of TLR4, implying a novel PTK-dependent pathway in innate immunity

Circulating miR-203 derived from metastatic tissues promotes myopenia in colorectal cancer patients

Sarcopenia frequently occurs in metastatic cancer patients. Emerging evidence has revealed that various secretory products from metastatic tumours can influence host organs and promote sarcopenia in patients with malignancies. Furthermore, the biological functions of microRNAs in cell-to-cell communication by incorporating into neighbouring or distal cells, which have been gradually elucidated in various diseases, including sarcopenia, have been elucidated. We evaluated psoas muscle mass index (PMI) and intramuscular adipose tissue content (IMAC) using pre-operative computed tomography imaging in 183 colorectal cancer (CRC) patients. miR-203 expression levels in CRC tissues and pre-operative serum were evaluated using quantitative polymerase chain reaction. Functional analysis of miR-203 overexpression was investigated in human skeletal muscle cells (SkMCs), and cells were analysed for proliferation and apoptosis. Expressions of several putative miR-203 target genes (CASP3, CASP10, BIRC5, BMI1, BIRC2, and BIRC3) in SKMCs were validated. A total of 183 patients (108 men and 75 women) were included. The median age of enrolled patients at diagnosis was 68.0 years (range 35-89 years). High IMAC status significantly correlated with female gender (P = 0.004) and older age (P = 0.0003); however, no other clinicopathological factors correlated with IMAC status in CRC patients. In contrast, decreased PMI significantly correlated with female gender (P = 0.006) and all well-established disease development factors, including advanced T stage (P = 0.035), presence of venous invasion (P = 0.034), lymphovascular invasion (P = 0.012), lymph node (P = 0.001), distant metastasis (P = 0.002), and advanced Union for International Cancer Control tumour-node-metastasis stage classification (P = 0.0004). Although both high IMAC status and low PMI status significantly correlated with poor overall survival (IMAC: P = 0.0002; PMI: P &lt; 0.0001; log-rank test) and disease-free survival (IMAC: P = 0.0003; PMI: P = 0.0002; log-rank test), multivariate Cox's regression analysis revealed that low PMI was an independent prognostic factor for both overall survival (hazard ratio: 4.69, 95% confidence interval (CI): 2.19-10, P = 0.0001) and disease-free survival (hazard ratio: 2.33, 95% CI: 1.14-4.77, P = 0.021) in CRC patients. Serum miR-203 expression negatively correlated with pre-operative PMI level (P = 0.0001, ρ = -0.25), and multivariate logistic regression analysis revealed that elevated serum miR-203 was an independent risk factor for myopenia (low PMI) in CRC patients (odds ratio: 5.16, 95% CI: 1.8-14.8, P = 0.002). Overexpression of miR-203 inhibited cell proliferation and induced apoptosis via down-regulation of BIRC5 (survivin) expression in human SkMC line. Assessment of serum miR-203 expression could be used for risk assessment of myopenia, and miR-203 might be a novel therapeutic target for inhibition of myopenia in CRC