Search

Introduction Varicocele, which is defined as varicose veins in the scrotum, is associated with different complications, in particular infertility. However, the definite etiologies have not determined yet. Our objective was to investigate the association between left lumbar, renal, and gonadal veins diameters and varicocele occurrence and grading in kidney donors underwent left-sided nephrectomy. Also, the frequency of varicocele were evaluated three months after the surgery. Methods In this observational study, male kidney donors aged 18 to 65, who underwent open nephrectomy were included between 2022 and 2023. Baseline data on age, body mass index (BMI), and the presence or grade of varicocele were collected through medical records and physical examinations. During the procedure, the diameter of the left lumbar, renal, and gonadal veins was measured using a graded ruler on the back Table. Three months after the nephrectomy, the patients were re-evaluated for varicocele recurrence. Results We included 30 kidney donor with a mean age of 38.2 years and BMI of 23.5 kg/m2. The renal vein diameter decreased with higher grading (P-Value=0.05) and the gonadal vein diameter increased with higher grading (P-Value=0.04). However, there was no significant association between varicocele grading and left lumbar vein diameter. Following three months of nephrectomy, the frequency of varicocele increased from 33.4% to 50.0%. Conclusions The diameter of the left lumbar vein was almost unchanged in varicocele, while the size of the left renal vein decreased, and the size of the left gonadal vein increased. Furthermore, occurrence of varicocele increased after three months of left-sided nephrectomy. Therefore, people undergoing nephrectomy are at a higher risk of developing varicocele which should be considered in follow-up visits. [ABSTRACT FROM AUTHOR]

Culture and worldview form the foundations of a society's existence and knowledge, which are transformed by various external and internal factors. One of the platforms that embodies these infrastructures in every culture is folklore narratives, the analysis of which can be used to recover sources that are less visible in historical documents. According to historical evidence, matriarchy culture in Zagros was the dominant social phenomenon before the widespread presence of Aryan peoples in the Iranian Plateau. Such phenomena bring with them certain subcultures and social customs that are represented at different social and literary levels. Exogamy is one of the characteristics of matriarchal culture, which can be found in the oral literature of Kurdistan. While examining the data on exogamy based on the worldview of matriarchy by using its data, the present study analyzes the content of three popular Kurdish oral narratives in an analytical-descriptive manner and shows that action and conflict in these narratives are the result of the clash of two cultures of exogamy (ex-marriage) and endogamy (in-marriage). [ABSTRACT FROM AUTHOR]

Key Clinical Message: Giant cell tumor of bone (GCT) is a rare neoplasm which often presents as a lytic lesion in the epiphyseal region of long bones and which are usually accompanied by pain, swelling, and restricted movement. Giant cell tumor of bone (GCT) is a rare neoplasm that affects individuals in their third and fourth decades of life. Clinically, it often presents as a lytic lesion in the epiphyseal region of bones, notably the distal femur and proximal tibia. Radiologically, GCT appears as a distinct lytic lesion in the epiphyseal region. Histopathologically, GCTs are composed of mononuclear cells, macrophages, and multinuclear giant cells, indicative of osteoclastogenic stromal tumors. A 37‐year‐old man presented with left wrist pain, swelling, and restricted movement persisting for a year, worsening over the last 7 months. Radiographic assessments revealed a distal radius bone mass involving the radiocarpal joint. Biopsy confirmed a GCT with extension into peripheral muscle. PET/CT scan showed localized pathology without metastasis. Histopathologically, GCT exhibited multinucleated giant cells, spindle cells, and aneurysmal bone cyst‐like regions with coagulation necrosis. Surgical resection involved en‐bloc removal and reconstruction with a non‐vascularized radius bone graft. Postoperatively, the patient showed no complications at the one‐year follow‐up, suggesting successful intervention. [ABSTRACT FROM AUTHOR]

This paper deals with the control and performance improvement of parallel-operated voltage-source inverters (VSIs) controlled as virtual synchronous generators (VSGs). In publications regarding the parallel-operated VSGs, transmission lines are considered to be mainly inductive. However, less analytical works have been done regarding the control of paralleled VSGs in low-voltage grids with dominant resistive impedances. Once VSIs are controlled as VSGs in a microgrid with more resistive transmission lines, swing equation and system representation for the power-angle synchronization will change leading to a new control structure. Therefore, this paper deals with the control of parallel-operated converter-based VSGs in low-voltage grids with dominant resistive line impedances. In this way, the VSG representation, comprising the swing equation and V-P droop characteristic, for applications in highly resistive microgrids is presented, in which the swing equation and VSG frequency are related to reactive power. Then, the V-P droop characteristic is modified and an enhanced P-V droop characteristic for proper sharing of active power between the VSGs in highly resistive microgrids is proposed. Next, the VSG control is modified so that the R/X ratio at the VSG output increases and thus the decoupled control of active/reactive powers in relatively inductive cases is realized as well. [ABSTRACT FROM AUTHOR]

This paper assesses the dynamic performance of permanent magnet synchronous generator‐based wind turbine (WT) regarding the blade in‐plane fatigue loads once the WT is controlled in power control mode. Blade in‐plane oscillations, associated with the poorly blade in‐plane modes, can be excited by turbulent winds or grid disturbances that may lead to damage of the blades and reduce the drive‐train reliability. To overcome this drawback, at first, a model with three degrees of freedom is extracted for the drive‐train system, and then, an active mitigation approach is proposed to mitigate the blade in‐plane oscillations. The proposed method can effectively suppress the blade in‐plane vibrations by adding a supplementary term into the power control loop that is proportional to the speed difference between the blade and generator. The speed difference between the blade and generator is obtained by estimation of the blade‐hub and hub‐generator shaft torsional torques. Next, the performance of the proposed active mitigation approach is examined by the modal and frequency response analyses and time‐domain simulations. Finally, it is shown that the proposed approach has superior performance over the conventional approaches based on the simplified drive‐train model and crossing the measured generator speed through a band‐pass filter. [ABSTRACT FROM AUTHOR]

Key Clinical Message: The modified nail folding approach, a new surgical technique, has been shown to be safe and effective for the treatment of subungual glomus tumors, providing clinicians with a new treatment option for patients with this condition. Glomus tumors (GTs) are rare benign tumors that originate from the glomus body in the skin of the fingertips, toes, and nail beds. GTs are more prevalent in women than in men and can occur sporadically or as part of an inherited condition known as multiple GTs. The exact cause of GTs is unknown, but it is believed that mutations in the cells of the glomus body contribute to their development. In this study, we present the efficacy of a novel surgical technique called the modified nail folding approach for treating subungual GTs. We report a case series involving 17 patients who underwent the nail folding approach for surgical removal of subungual GTs. The primary objective of this article is to provide evidence supporting the safety and effectiveness of this technique. Additionally, we aim to introduce clinicians to a new, secure, and efficient treatment option for patients with subungual GTs. [ABSTRACT FROM AUTHOR]

This paper deals with the stability analysis and enhancement in the AC‐microgrid system comprising parallel‐operated voltage‐source inverters (VSIs) supplying an active‐load. The active‐load behaves such as a constant power load from the AC‐side. In the paper, two models for the active‐load modeling in the AC microgrid are considered: (i) simple model in which the active‐load is modeled as an ideal current source, (ii) detailed model in which all dynamics of the active‐load converter and related controllers are taken into account. The main findings and contribution of this paper are as follows. (a) All linearized state equations of the study system are extracted and transferred into a unified common dq‐reference frame, and then, small‐signal stability of the study system is carried out in the common reference frame by using the simple and detailed models of the active‐load. (b) It is shown that the simple model of the active‐load, as a current source, leads to more pessimistic results in comparison to the active‐load detailed model. (c) Impacts of the active‐load power and bandwidth of the active‐load voltage control loop on the system stability are examined. (d) Control of the generation‐side VSIs is modified and a stabilizing approach, called generation‐side virtual capacitor, is proposed for stabilizing the system under high active‐load penetration. Next, modal analysis and time‐domain simulations are used to investigate the study system responses with and without the proposed stabilizing approach. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Osteochondromas (OCs) are developmental anomalies that originate from the periosteum and typically form during enchondral ossification near the joints. Retro‐patellar OC caused by exostosis forms in various intracapsular, intra‐tendon, and joint‐adjacent positions within the knee joint. In this case, a 19‐year‐old male presented with swelling and a mass in his left knee, which raised suspicion of bone tumors. After evaluating x‐ray images and conducting histopathological examinations, the diagnosis was confirmed as retro‐patellar OC. [ABSTRACT FROM AUTHOR]

Background: Early graft loss (EGL) is one of the rare complications of kidney transplantation. Several factors play a role in the occurrence of EGL in kidney transplant recipients, which must be identified and limited. Objectives: This ten-year retrospective study was conducted in a single center on 32 kidney transplant recipients with EGL to determine the reasons for and risk factors of kidney transplant rejection in Iran. Methods: This descriptive-analytical study's population included 605 kidney transplant recipients receiving kidneys during the last ten years in our center. The diagnosis of EGL was based on renal allograft biopsy examination and primary clinical complications, including a rapid increase in serum creatinine. The age, gender, blood group, and rhesus (Rh) of both donors and recipients, as well as the kinship between the donor and recipient (relative and non-relative), right/left-sided living donor/recipient kidneys, primary kidney disease, the presence of underlying disease in the recipient, dialysis duration, the year of kidney transplantation, transplant survival time, patient survival time, and complications (surgery and others) were gathered. The data were analyzed using SPSS version 18. Results: In this study, 32 out of 605 kidney transplant recipients (5.28%) experienced EGL (53.1% male and 46.9% female, average age of 41.12 years). The duration of kidney function after transplantation was 5.56 ± 0.13 days. The transplanted kidneys were functional between 72 hours and one week after transplantation in 34.4% of the patients. The causes of EGL were found to be tissue rejection in 31.3% of the patients and vascular thrombosis and hyperacute rejection in 21.8%. Nephrectomy occurred in 41% of the patients, and 43.75% died because of a heart attack. Conclusions: Our findings supported previous studies' results, suggesting that EGL is associated with receiving an incompatible kidney transplant and surgery-related complications, including bleeding and thrombosis. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Intramuscular myxoma (IMM) is a benign soft tissue tumor of mesenchymal origin that occurs mainly in skeletal muscles which can be removed through surgery after diagnosis. Intramuscular myxoma (IMM) is a benign soft tissue tumor of mesenchymal origin that typically occurs in skeletal muscles. Its diagnosis is based on magnetic resonance imaging (MRI) and histopathologic evaluation of the lesion. In our report, we describe the case of a 60‐year‐old female with an IMM in the supinator muscle of the right forearm, which was confirmed by MRI and histopathologic examination. Following surgery to remove the mass, a follow‐up confirmed the patient's recovery and the absence of movement limitations in the elbow joint. [ABSTRACT FROM AUTHOR]

This paper deals with the integration and control of the doubly fed induction generator‐based wind turbine (DFIG‐WT) in a DC grid. In this way, the stator of the DFIG‐WT is integrated with the DC grid via an uncontrolled diode‐bridge rectifier as well as a buck converter to provide a flexible connection path. In addition, the rotor of the DFIG‐WT exchanges power with the DC grid through a rotor‐side converter (RSC). By considering the DFIG‐WT system topology, three control strategies based on the stator flux‐oriented vector control are developed for the RSC and buck converter. The control schemes consist of the outer and the inner control loops with the proportional–integral (PI) controllers. Additionally, the stability of control strategies and their dependence on the generator parameters are evaluated and compared using modal analysis and numerical simulations in the MATLAB/SIMULINK environment. Finally, a real‐time hardware‐in‐the‐loop emulation‐based OPAL‐RT 5600 is accomplished to assess the performance of the superior control method from a practical perspective. [ABSTRACT FROM AUTHOR]

Due to the negative impedance potential of constant power loads (CPLs), the stability of power electronic converters-based electrical distribution networks is prone to instability. This brief proposes a robust control technique based on deep reinforcement learning to stabilize a DC microgrid (MG) with parallel boost converters when feeding CPLs. For this purpose, a model-free sliding mode controller (MFSMC) has been applied to the DC MG. The MFSMC controller does not need any identification of converters in the DC MG system while ensuring the efficiency and the stability of the control synthesis. The key control coefficients are designed by Proximal Policy Optimization (PPO) Reinforcement Learning (RL). The PPO is made from two deep neural networks (NNs) (actor NN and critic NN) which are trained to adjust the coefficients of the MFSMC controller. The MFSMC controller designed by the PPO with actor-critic architecture is applied to the DC MG system feeding CPL in an OPAL-RT setup to verify the efficiency of the proposed controller through Hardware-in-the-Loop (HiL) simulations. [ABSTRACT FROM AUTHOR]

Integration of doubly‐fed induction generator (DFIG) based wind turbines (WTs), in series‐compensated power grids, may result in a phenomenon known as sub‐synchronous control interaction (SSCI). Indeed, SSCI, created due to interaction between WTs controllers and series‐compensated power grid, may worsen damping of sub‐synchronous resonance (SSR) oscillations. This paper deals with the analytical assessment and mitigation of SSCI phenomenon in series compensated grids comprising of DFIG‐based WTs. In this way, first, theoretical and mathematical expressions and equivalent circuits regarding the SSCI phenomenon and the impacts of the RSC and GSC controls on the SSR oscillations damping are given and then a comprehensive impedance model for the DFIG‐WT at the sub‐synchronous frequency is extracted. Next, the rotor current control is modified, and an efficient approach based on the feedback linearizing technique (FLT), different from approaches presented in the related literature, is presented to mitigate the negative role of the DFIG in SSR frequencies. By mathematical analyses and developing related formula, it is shown that the proposed approach changes the impedance of the rotor circuit to infinity at the SSR frequency. This in turn results in suppression of the SSR oscillations initiated as a result of induction generator effect and SSCI phenomenon. [ABSTRACT FROM AUTHOR]

Commonly, a simple topology consisting of a single diode‐rectifier and pulse‐width‐modulation (PWM) converter is used for the connection of the doubly‐fed induction generator‐based wind turbines (DFIG‐WTs) to the DC grid, in which the rotor‐side converter (RSC) and the stator diode‐rectifier are linked to the common DC bus. But, this topology suffers from less flexibility due to the requirement of matching the stator nominal voltage with the DC grid. Hence, in this paper, a buck converter is added to the DFIG‐WT topology and two methods are proposed to control the power converters, where in the first one, the RSC regulates the active power and stator flux linkage, and in the second one, the RSC regulates the DC bus voltage and stator flux linkage. Then, the small‐signal stability and the performance of the DFIG‐WT system with the mentioned control strategies are compared analytically and through the off‐line simulations. At last, a real‐time hardware‐in‐the‐loop (HIL) emulation‐based OPAL‐RT is carried out to investigate the performance of the proposed control methods from a practical perspective. [ABSTRACT FROM AUTHOR]

Infertility is defined as the failure to achieve a successful pregnancy after 12 months' sexual activity that affects 15%–17% of couples in the world and about 50% of them are related to female infertility factors. In this study, using the PRISMA checklist and MeSH keywords, 128 articles were extracted from various databases (PubMed, Cochrane library, WHO, Iranmedex, Science Direct, SID, and Google Scholar search engine) without language and time restrictions, and 128 articles were selected after eliminating duplicate studies. In this review, we present some solid evidence for role of herbal medicine in the treatment of female infertility. The results of this study showed that different parts of some plants are rich in polyphenolic compounds (isoflavones and flavonoids) and other compounds which are beneficial to in reproductive health in women. The compounds in these plants, along with regulating the female endocrine pathways, and improving symptoms of menopause, treat female reproductive disorders such as polycystic ovary syndrome (PCOS), premature ovarian failure (POF), endometriosis, hyperprolactinemia, and hypothalamic dysfunction; moreover, because of their anticancer, antioxidant, and antidepressant properties, they can be used in traditional medicine or in the pharmaceutical industry as safe compounds in women's health. [ABSTRACT FROM AUTHOR]

Abstract Background Restless Legs Syndrome (RLS) is a common neurological movement disorder characterized by symptoms that follow a circadian pattern. Night and rotating shift work schedules exert adverse effects on functions of the human body by disturbing circadian rhythms, and they are known to cause sleep disturbances and insomnia. In this paper, we investigate the possible association between shift work and RLS. Methods This cross sectional study was conducted in an automobile manufacturing factory in Tehran, Iran. A total of 780 male assembly workers were recruited in three groups, each with 260 workers: workers on a permanent morning shift (A) and two different rotating shift schedules (B and C) with morning, afternoon and night shifts. We used the international RLS study group criteria for diagnosis of RLS, and the severity scale for severity assessment in subjects with RLS. Self administered questionnaires were used to gather information on age, smoking, work history, medical condition, and existence and severity of RLS symptoms. Results The prevalence of RLS was significantly higher in rotational shift workers (15%) than workers with permanent morning work schedule (8.5%). In workers suffering from RLS, we found greater mean values of age and work experience, higher percentages of drug consumption, smoking, and co-morbid illnesses compared with subjects who did not have RLS, although these differences were statistically significant only for age, work experience and drug consumption. Conclusion Rotational shift work acts as a risk or exacerbating factor for Restless Legs Syndrome.