An Uncommon Recurrent Metastasis of Ovarian Immature Teratoma to the Small Bowel

Immature ovarian teratomas are rare ovarian germ cell tumors associated with a variable potential of distant metastasis. The acquisition of mature phenotypes upon post-treatment recurrence of immature teratomas has been previously described. In this study, we report, for the first time, a rare case of a recurrent ovarian immature teratoma with mature deposits in the small bowel. An incidental pelvi-abdominal mass was identified in a 30-year-old pregnant patient during antenatal ultrasonography. The mass, which was resected through salpingo-oopherectomy, was histopathologically characterized as an immature teratoma of grade 2 and treated with 3 cycles of chemotherapy. After 3 years of completing treatment, the patient suffered from severe anemia which was investigated by capsule endoscopy that identified a bleeding source in the ileum. Imaging studies revealed an intrabdominal mass that was resected laparoscopically. The pathological assessment of the mass identified a submucosal/intramuscular teratoma with mature elements indicative of a recurrent metastasis of immature teratoma associated with post-chemotherapy retroconversion. The secondary mass was then managed with adjuvant chemotherapy.

Existence of ground state solutions for a class of Choquard equations with local nonlinear perturbation and variable potential

In this paper, we focus on the existence of solutions for the Choquard equation $$\begin{aligned} \textstyle\begin{cases} {-}\Delta {u}+V(x)u=(I_{\alpha }* \vert u \vert ^{\frac{\alpha }{N}+1}) \vert u \vert ^{ \frac{\alpha }{N}-1}u+\lambda \vert u \vert ^{p-2}u,\quad x\in \mathbb{R}^{N}; \\ u\in H^{1}(\mathbb{R}^{N}), \end{cases}\displaystyle \end{aligned}$$ { − Δ u + V ( x ) u = ( I α ∗ | u | α N + 1 ) | u | α N − 1 u + λ | u | p − 2 u , x ∈ R N ; u ∈ H 1 ( R N ) , where $\lambda >0$ λ > 0 is a parameter, $\alpha \in (0,N)$ α ∈ ( 0 , N ) , $N\ge 3$ N ≥ 3 , $I_{\alpha }: \mathbb{R}^{N}\to \mathbb{R}$ I α : R N → R is the Riesz potential. As usual, $\alpha /N+1$ α / N + 1 is the lower critical exponent in the Hardy–Littlewood–Sobolev inequality. Under some weak assumptions, by using minimax methods and Pohožaev identity, we prove that this problem admits a ground state solution if $\lambda >\lambda _{*}$ λ > λ ∗ for some given number $\lambda _{*}$ λ ∗ in three cases: (i) $2< p<\frac{4}{N}+2$ 2 < p < 4 N + 2 , (ii) $p=\frac{4}{N}+2$ p = 4 N + 2 , and (iii) $\frac{4}{N}+2< p<2^{*}$ 4 N + 2 < p < 2 ∗ . Our result improves the previous related ones in the literature.

A Curve-Shaped Beam Bistable Piezoelectric Energy Harvester with Variable Potential Well: Modeling and Numerical Simulation

To improve the energy harvesting performance of an energy harvester, a novel bistable piezoelectric energy harvester with variable potential well (BPEH-V) is proposed by introducing a spring to the external magnet from a curve-shaped beam bistable harvester (CBH-C). First, finite element simulation was performed in COMSOL software to validate that the curved beam configuration was superior to the straight beam in power generation performance, which benefits energy harvesting. Moreover, the nonlinear magnetic model was obtained by using the magnetic dipoles method, and the nonlinear restoring force model of the curve-shaped beam was acquired based on fitting the experimental data. The corresponding coupled governing equations were derived by using generalized Hamilton’s principle, the dynamic responses were obtained by solving the coupling equations with the ode45 method. Finally, the numerical simulations showed that the proposed harvester can make interwell oscillations easier due to the spring being efficiently introduced to pull down the potential barrier compared with the conventional bistable harvester. Spring stiffness has a great impact on characteristics of the system, and a suitable stiffness contributes to realize large-amplitude interwell oscillations over a wide range of excitation, especially in the low excitation condition.

Comparing the Membrane Potential of Wheat Grains of Different Varieties and Productivity Divided into Fractions According to Their Aerodynamic Properties

Introduction. Spring wheat yield depends largely on the wheat variety, seed quality, cultivation technology, and agro-climatic factors. It has been found that the separation of wheat seeds into fractions makes it possible to improve the quality of post-harvest processing, adjust the quality of grain depending on the intended use, and the sowing of the wheat grains divided into fractions allows increasing productivity. The aim of the article is to explore the membrane potential on the shells of wheat grains divided into fractions according to their aerodynamic properties and to compare certain membrane potential features with aerodynamic properties of these grains and the yields of selected varieties. Materials and Methods. The seeds, divided into fractions, have different sowing qualities. Biologically deficient seeds have poor germination index. The study have found that the division of seeds into fractions contributes to increasing yields, but the main indicators of quality are still germination and viability, for this reason an approach has been developed to determine the quality of wheat seeds divided into fractions. Results. This article studies the change in membrane potential of wheat seeds, divided into fractions according to their aerodynamic properties. The article presents the results of testing a new clamping electrode with a smooth surface to measure the membrane potential of wheat gains. To study the effect of the wheat variety, the aerodynamic properties of grains and yield on changes in membrane potential, we analyzed three indices: the resting potential level, time of variable potential rise to the maximum value and variable potential maximum value. Discussion and Conclusion. New informative indicators have been determined because of the two-way analysis of variance of the research results. These indicators reliably reflect the aerodynamic properties of seeds and can be used to predict yields. The use of the obtained results will allow agricultural enterprises and farms to determine the quality of post-harvest processing of wheat seeds, adjust the quality depending on the intended use, and evaluate and forecast the productivity of seeds.

Potential Climate Benefits of Digital Consumer Innovations

Digitalization has opened up a wealth of new goods and services with strong consumer appeal alongside potential emission-reduction benefits. Examples range from shared, on-demand electric mobility and peer-to-peer trading of electricity, food, and cars to grid-responsive smart appliances and heating systems. In this review, we identify an illustrative sample of 33 digital consumer innovations that challenge emission-intensive mainstream consumption practices in mobility, food, homes, and energy domains. Across these domains, digital innovations offer consumers a range of potentially appealing attributes from control, choice, and convenience to independence, interconnectedness, and integration with systems. We then compile quantitative estimates of change in activity, energy, or emissions as a result of consumers adopting digital innovations. This novel synthesis of the evidence base shows clear but variable potential emission-reduction benefits of digital consumer innovations. However, a small number of studies show emission increases from specific innovations as a result of induced demand or substitution effects that need careful management by public policy. We also consider how concurrent adoption of digital consumer innovations across mobility, food, homes, and energy domains can cause broader disruptive impacts on regulatory frameworks, norms, and infrastructures. We conclude by arguing for the importance of public policy in steering the digitalization of consumer goods and services toward low-carbon outcomes.

Metal Mobility in a Mine-Affected Floodplain

The study attempted to map and predict the remobilization of metals in a floodplain which had been heavily affected by long-term Zn–Pb mining. This research, based on Zn, Cd, Pb, Ca and Fe speciation, mineralogy and the stratigraphy of sediments which had accumulated over the distance of a dozen or so km from the mine, revealed variable potential for metal mobilization. The results suggest that a drop in the water table, something to be expected after the closure of a mine, would be accompanied by a decrease in the pH of the river water and can induce the remobilization of metals associated with carbonates and exchangeable cations over the short-reach downstream of the mine. However, the mobilization of contaminants may be impeded by the alkaline, impermeable stratum of loams, which play a pivotal role in maintaining anaerobic conditions and buffering the acidity resulting from the partial degradation of sulfides. Based on the findings of the study, it can be expected that the intrinsic attenuation will limit the need for remediation works, although monitoring river water quality is recommended to determine the need for any intervention in cases where permissible quality values have been exceeded over a longer period. Results of this research can be useful as a reference for remediation works planned in other contaminated river systems experiencing water table lowering, where the mobilization of contaminants as a consequence of sediment oxidization can be expected.