Optimal performance of voltage-probe quantum heat engines

The thermoelectric performance at a given output power of a voltage-probe heat engine, exposed to an external magnetic field, is investigated in linear irreversible thermodynamics. For the model, asymmetric parameter, general figures of merit and efficiency at a given output power are analytically derived. Results show a trade-off between efficiency and output power, and we recognize optimum-efficiency values at a given output power are enhanced compared to a B\"uttiker-probe heat engine due to the presence of a characteristic parameter, namely $d_m$. Moreover, similar to a B\"uttiker-probe heat engine, the universal bounds on the efficiency are obtained, and the efficiency at a given output power can exceed the Curzon-Ahlborn limit. These findings have practical implications for the optimization of realistic heat engines and refrigerators. By controlling the values of the asymmetric parameter, the figures of merit, and $d_m$, it may be possible to design more efficient and powerful thermoelectric devices.Comment: 14 pages including 6 multi-panel figure

Excited-Eigenstate Entanglement Properties of XX Spin Chains with Random Long-Range Interactions

Quantum information theoretical measures are useful tools for characterizing quantum dynamical phases. However, employing them to study excited states of random spin systems is a challenging problem. Here, we report results for the entanglement entropy (EE) scaling of excited eigenstates of random XX antiferromagnetic spin chains with long-range (LR) interactions decaying as a power law with distance with exponent $\alpha$. To this end, we extend the real-space renormalization group technique for excited states (RSRG-X) to solve this problem with LR interaction. For comparison, we perform numerical exact diagonalization (ED) calculations. From the distribution of energy level spacings, as obtained by ED for up to $N\sim 18$ spins, we find indications of a delocalization transition at $\alpha_c \approx 1$ in the middle of the energy spectrum. With RSRG-X and ED, we show that for $\alpha>\alpha^*$ the entanglement entropy (EE) of excited eigenstates retains a logarithmic divergence similar to the one observed for the ground state of the same model, while for $\alpha<\alpha^*$ EE displays an algebraic growth with the subsystem size $l$, $S_l\sim l^{\beta}$, with $0<\beta<1$. We find that $\alpha^* \approx 1$ coincides with the delocalization transition $\alpha_c$ in the middle of the many-body spectrum. An interpretation of these results based on the structure of the RG rules is proposed, which is due to {\it rainbow} proliferation for very long-range interactions $\alpha\ll 1$. We also investigate the effective temperature dependence of the EE allowing us to study the half-chain entanglement entropy of eigenstates at different energy densities, where we find that the crossover in EE occurs at $\alpha^* < 1$.Comment: 11 pages, 13 figure

Changing the Human Genome from the Perspective of Fundamental Moral Principles

زمینه و هدف: پروژه ژنوم انسانی در مفهوم عام خود پروژه‌ای ژنتیکی است که با مهندسی ژنتیک یک انسان، امکان ایجاد هرگونه تغییر در نژاد انسان، اعم از ترمیم یا ارتقای ژنتیکی و حتی تولید انسان جدید بدون نیاز به نطفه پدر را فراهم می‌کند. از آنجا که تاریخ آغاز مطالعات ژنتیکی قدمت طولانی ندارد، مسأله شبیه‌سازی در حوزه امور مستحدثه قرار می‌گیرد. ملاحظات اخلاقی در واقع ناظر بر موانع اخلاقی است که در اثر ژنوم انسانی ممکن است پدید آید. بنابراین پژوهش حاضر درصدد است تا این نکات اخلاقی را مورد توجه قرار دهد. مواد و روش‌ها: برای بررسی موضوع حاضر از روش توصیفی ـ تحلیلی بهره برده شده است که در زمره روش‌های کیفی به حساب می‌آید. روش حاضر با جمع‌آوری اطلاعات از متون و منابع اسنادی در حیطه اخلاقی و پزشکی به بررسی موضوع تغییر ژنوم انسانی می‌پردازد. یافته‌ها: شبیه‌سازی انسان نیازمند در نظرگرفتن ملاحظات اخلاقی فراوانی است که از جهات مختلفی از جمله: عدم امنیت تکنیکی و پزشکی، سست‌شدن نهاد خانواده و نقض اصل کرامت انسانی و خدشه‌دارشدن نسب انسانی، عدم برخورداری از هویت فردی و رشد روانی کامل، ایجاد رویکرد نژادپرستانه و ایجاد نژاد برتر، نقض آفرینش انسان و دستکاری در کار خداوند را دربر می‌گیرد. نتیجه‌گیری:&nbsp; قوانین و قواعد مربوط به شبیه‌سازی در حقوق ایران مبهم و دارای ابعاد مختلفی هستند که نمی‌توان پشتوانه حقوقی محکمی برای حمایت از شبیه‌سازی فراهم آورد. تنها مواردی که دیده می‌شود، قواعد مربوط به ارث حمل، وصیت برای حمل و اقرار به نفع حمل است که در حوزه شبیه‌سازی از آنان نتایحی استخراج می‌شود. بنابراین از منظر حقوقی نیازمند وجود قوانین شفاف درباره شخصیت و هویت جنین و فرایند شبیه‌سازی هستیم. تأسیس قوانینی جهت شفاف‌سازی سازوکارهای بهره‌گیری از فناوری شبیه‌سازی امری ضروری است.Background and Aim: Human genome project in its general sense is a genetic project that with the genetic engineering of a human provides the possibility of any change in the human race, including genetic repair or improvement and even the production of a new human without the need for a father sperm. he does. Since the date of the beginning of genetic studies is not long, the issue of simulation is in the realm of emerging affairs. Ethical considerations actually address the moral barriers that may arise from the human genome. Therefore, the present study seeks to address these ethical points. Materials and Methods: Descriptive-analytical method has been used to investigate the present issue, which is considered as a qualitative method. The present method examines the issue of human genome change by collecting information from texts and documentary sources in the field of ethics and medicine. Findings: Human simulation needs to consider many ethical considerations from various aspects, including: lack of technical and medical security; Weakening of the family institution and violation of the principle of human dignity and damage to human lineage; Lack of personal identity and full psychological development; Creating a racist approach and creating a superior race; It includes the violation of human creation and the manipulation of God's work. Conclusion: The rules and regulations related to simulation in Iranian law are ambiguous and have various dimensions that cannot provide strong legal support to support simulation. The only cases that can be seen are the rules related to inheritance of transportation, wills for transportation and acknowledgment in favor of transportation, from which results are extracted in the field of simulation. Therefore, from a legal point of view, we need clear rules about the personality and identity of the fetus and the simulation process. Establishing rules to clarify the mechanisms for using simulation technology is essential. &nbsp; Please cite this article as: Vahedi J, Ahmadi SM. Changing the Human Genome from the Perspective of Fundamental Moral Principles. Bioethics Journal, Special Issue on Bioethics and Citizenship Rights 2020; 213-224

Bilateral Femoroacetabular Impingement: The Fate of the Asymptomatic Hip

Introduction: The objective of this study was to evaluate the incidence of bilateral femoroacetabular impingement (FAI) in a consecutive group of patients and to evaluate the fate of the asymptomatic hip with FAI. Method: Between 2004 to 2016, 652 patients presented with hip pain arising from underlying FAI. Diagnosis of FAI was made based on clinical symptoms and imaging. 557 patients (646 hips) were included for the final analysis. Of these, 170 patients had bilateral radiological diagnosis of FAI. Of these, 88 patients presented with bilateral hip symptoms. The remaining 82 patients had unilateral hip symptoms. Of these 82 patients, 8 patients decided to have surgery on both hips under the same anesthesia. The remaining 74 patients decided to have the contralateral asymptomatic hip with FAI observed. Results: Of the cohort with bilateral FAI and an asymptomatic hip, 60 patients became symptomatic at an average 2.1 years follow-up. Of these 60 patients 43 patients needed surgical intervention. Binary logistic regression model identified that reduced neck shaft angle, increased lateral CE angle and increased alpha angle, younger age as predictors for developing symptoms in the contralateral hip. Discussion: Based on this study it appears that the incidence of bilateral FAI is common. The majority of patients with unilateral symptomatic FAI and radiographic evidence of bilateral FAI become symptomatic relatively quickly and require surgical intervention in the contralateral hip

The effects of letrozole-induced maternal hyperandrogenism on sexual behaviors, testicular histology, and serum biochemical traits in male offspring rats: An experimental study

Background: Intrauterine endocrine abnormalities have profound effects on the development of physiological disorders. Objective: This study aimed to assess the effects of in utero exposure to letrozole (an aromatase inhibitor) and its late consequences on the reproductive and metabolic performance of an adult male offspring. Materials and Methods: 15 pregnant Sprague-Dawley rats (8 wk, 155 gr) were randomly assigned into 5 experimental groups (n = 3/each) and orally received either letrozole at doses of 0.25, 0.75, 1.00, and 1.25 mg/kg body weight (BW) or vehicle (control) on the gestation days of 16, 17, and 18. Pregnancy outcome, sexual behaviors on postnatal day 60, serum biochemical features, and the histopathology of testes were assessed in male offspring. Results: Compared to control group, delayed labor (21.83 vs. 24.25, p &lt; 0.0001) and reduced litter size (n = 12.25 vs. n = 2, p &lt; 0.0001) were recorded in 1.25 mg/kg BW group. A reduction in high-density lipoprotein level and the elevation of testes weight, BW gain, anogenital distance, as well as the serum concentrations of testosterone, triglycerides, cholesterol, and glucose were observed in 1.25 mg/kg BW (p &lt; 0.0001) and 1.00 mg/kg BW (p &lt; 0.0001) groups in comparison to control. A larger number of anogenital female sniffing, pursuit, and mounting behaviors were also observed in 1.25 mg/kg BW group in comparison to control (p &lt; 0.0001). Severe testicular defects including necrosis and disruption of the epithelium of seminiferous tubules, sloughing of epithelial cells, and spermatogenesis arrest were observed in letrozole-treated groups, in a dose-dependent manner. Conclusion: Maternal exposure to letrozole can adversely affect the reproductive and metabolic performance of male offspring rats, suggesting an incomplete sex differentiation. Key words: Androgens, Aromatase inhibitors, Rat, Sexual activities, Testes histopathology