Choriocarcinoma metastatic to both kidneys presenting with spontaneous renal hemorrhage: Case report.

INTRODUCTION: Choricocarcinoma is a highly malignant tumor. It metastasize commonly to the lungs. Metastasis to the kidney is uncommon, and bilateral metastasis is described rarely. Initial presentation with spontaneous bleeding of the renal metastatic tumor is scarce in the literatures. Here we present a case report of a choriocarcinoma patient with bilateral renal metastasis, presenting with spontaneous renal hemorrhage. CASE PRESENTATION: A 22 years old female presented to our emergency department with sudden onset of left flank pain. She has history of spontaneous abortion 02 years back with biopsy from the manual vacuum aspiration (MVA) showing molar pregnancy. Up on evaluation, patient was anemic. CT scan showed left renal bleeding tumor. Exploratory laparotomy and radical nephrectomy was done with the impression of bleeding renal cell carcinoma. The biopsy revealed choriocarcinoma. On her follow up, CT scan showed right renal and brain metastasis. She was given multi agent chemotherapy and her serum beta-hCG became undetectable after 01 year. DISCUSSION: Choriocarcinoma can be gestational or nongestational. The commonest route of metastasis is hematogenous. Presenting symptoms of renal metastasis can be hematuria, pain or more commonly incidental finding during work up. Choriocarcinoma is highly chemo sensitive. CONCLUSION: Bilateral renal metastatic choriocarcinoma is uncommon. Spontaneous renal hemorrhage as an initial presentation is even rare, and it can mimic a bleeding renal cell carcinoma. High index of suspicion is needed in a young women with recent history of spontaneous abortion.

Human capital development and economic sustainability linkage in Sub-Saharan African countries: Novel evidence from augmented mean group approach.

Sustainable Development Goal number four (SDG-4) strongly emphasizes quality education, which is crucial to human capital development. The importance of human capital development for sustainable economic development has thus risen to the top of the global policy agenda. However, the empirical literature on the topic has several limitations, including utilizing inappropriate measurement of human capital development and being unable to investigate the quality dimensions of education. Therefore, this study used years of schooling and return on education to fill the gap, and also considered the role of institutional and political factors in its empirical estimation. The main objective of this study is to investigate the effect of human capital development on economic sustainability in 30 Sub-Saharan African countries, employing panel data from 2000 to 2020. The augmented mean group model was used in the empirical investigation. The findings of the study showed that human capital development negatively and significantly affects economic sustainability in Sub-Saharan African countries. Thus, among the policy alternatives that Sub-Saharan African countries and policymakers should pursue to attain the goals of economic sustainability is revisiting the entire human capital development architecture and putting more of an emphasis on quality education than on access to education.

A computational investigation of cis-gene regulation in evolution.

In biological processes involving gene networks, genes regulate other genes that determine the phenotypic traits. Gene regulation plays an important role in evolutionary dynamics. In a genetic algorithm, a trans-gene regulatory mechanism was shown to speed up adaptation and evolution. Here, we examine the effect of cis-gene regulation on an adaptive system. The model is haploid. A chromosome is partitioned into regulatory loci and structural loci. The regulatory genes regulate the expression and functioning of structural genes via the cis-elements in a probabilistic manner. In the simulation, the change in the allele frequency, the mean population fitness and the efficiency of phenotypic selection are monitored. Cis-gene regulation increases adaption and accelerates the evolutionary process in comparison with the case involving absence of gene regulation. Some special features of the simulation results are as follows. A low ratio of regulatory loci and structural loci gives higher adaptation for fixed total number of loci. Plasticity is advantageous beyond a threshold value. Adaptation is better for large number of total loci when the ratio of regulatory loci to structural loci is one. However, it reaches a saturation beyond which the increase in the total loci is not advantageous. Efficiency of the phenotypic selection is higher for larger value of the initial plasticity.

Efficiency, power, and period at two optimum operations of a thermoelectric single-level quantum dot.

We take a single-level quantum dot embedded between two metallic leads at different temperatures and chemical potentials which works as a heat engine. Two optimization criteria were used and their corresponding optimized efficiencies, powers, and periods evaluated. A comparison between similar quantities of the two optimization criteria reveals mixed advantages and disadvantages. We quantify the engine's overall performance by suggesting a figure of merit that takes into account the contribution of each of the three quantities. Based on the proposed figure of merit, one of the optimization criterion presents a clear advantage. This same criterion is found to be invariably advantageous when applied to three other representative models.

Energetics of a simple microscopic heat engine.

We model a microscopic heat engine as a particle hopping on a one-dimensional lattice in a periodic sawtooth potential, with or without load, assisted by the thermal kicks it gets from alternately placed hot and cold thermal baths. We find analytic expressions for current and rate of heat flow when the engine operates at steady state. Three regions are identified where the model acts either as a heat engine or as a refrigerator or as neither of the two. At the quasistatic limit both efficiency of the engine and coefficient of performance of the refrigerator go to that for Carnot engine and Carnot refrigerator, respectively. We investigate efficiency of the engine at two operating conditions (at maximum power and at optimum value with respect to energy and time) and compare them with those of the endoreversible and Carnot engines.