Superior Approach Research Articles

Quaternion-based adaptive backstepping fast terminal sliding mode control for quadrotor UAVs with finite time convergence

This paper proposes a novel quaternion-based approach for tracking the translation (position and linear velocity) and rotation (attitude and angular velocity) trajectories of underactuated Unmanned Aerial Vehicles (UAVs). Quadrotor UAVs are challenging regarding accuracy, singularity, and uncertainties issues. Controllers designed based on unit-quaternion are singularity-free for attitude representation compared to other methods (e.g., Euler angles), which fail to represent the vehicle's attitude at multiple orientations. Quaternion-based Adaptive Backstepping Control (ABC) and Adaptive Fast Terminal Sliding Mode Control (AFTSMC) are proposed to address a set of challenging problems. A quaternion-based ABC, a superior recursive approach, is proposed to generate the necessary thrust handling unknown uncertainties and UAV translation trajectory tracking. Next, a quaternion-based AFTSMC is developed to overcome parametric uncertainties, avoid singularity, and ensure fast convergence in a finite time. Moreover, the proposed AFTSMC is able to significantly minimize control signal chattering, which is the main reason for actuator failure and provide smooth and accurate rotational control input. To ensure the robustness of the proposed approach, the designed control algorithms have been validated considering unknown time-variant parametric uncertainties and significant initialization errors. The proposed techniques have been compared to state-of-the-art control technique.

Endoscopic Transorbital Resection of Temporal Pole Cavernoma: 2-Dimensional Operative Video.

An endoscopic transorbital approach has been recently included in the neurosurgical armamentarium.1 We present a case of a 31-year-old female patient with a history of recent-onset refractory epilepsy related to a left temporal pole cavernoma operated through a superior eyelid endoscopic transorbital approach. The operative video shows the key surgical steps to ensure optimal surgical freedom, adequate exposure, and complete tumor resection.2 The postoperative course was uneventful, and the patient obtained seizure control and good cosmetic results without postoperative complications. The brain computed tomography and MRI showed the size of bone removal and confirmed the complete removal of the lesion, respectively. At 3-month follow-up, the patient is epileptic seizures-free without medications. An endoscopic transorbital approach provides adequate exposure of the temporal pole, allowing safe tumor resection. Complication avoidance encompasses careful dissection of palpebral muscles, dynamic orbital retraction, and neuronavigation guidance; sphenoidal drilling according to key anatomic landmarks (eg, sagittal crest3); and anatomic knowledge of the cavernous sinus and internal carotid artery and its tributaries course from a transorbital perspective4 and reconstruction filling the empty spaces using fat, fascia lata, or dural substitutes. All procedures performed were approved by the ethics committee of both centers and in accordance with Declaration of Helsinki and its later amendments. The patient consented to the procedure and to the publication of her images, and appropriate consent was obtained for publication of cadaveric images.

Excisional biopsy of perforated gastric ulcer: mandatory or potentially harmful?

PurposeThis study aimed to evaluate the morbidity associated with excisional biopsy in patients with spontaneous gastric perforation.MethodsA retrospective, single-center, observational study was performed. All consecutive patients with spontaneous gastric perforation who underwent surgical therapy were included. Outcomes were assessed concerning the performance of excisional biopsy.ResultsA total of 135 adult patients were enrolled. Of these, 110 (81.5%) patients underwent excisional biopsy, while 17 (12.6%) did not. The remaining eight (5.9%) patients who underwent gastric resection were excluded from the analysis. Patients undergoing excisional biopsy developed significantly higher rates of postoperative complications (p = 0.007) and experienced more severe complications according to the Clavien-Dindo classification, particularly type III and above (p = 0.017). However, no significant differences were observed regarding in-hospital mortality, reoperation, suture dehiscence, or length of hospital stay.ConclusionExcisional biopsy for gastric perforation has been shown to be associated with increased morbidity. Surgical closure followed by early endoscopic biopsy may be a superior approach for gastric perforation management to rule out malignancy.

A review of assessment methods for measuring individual differences in oral somatosensory perception.

While taste and smell perception have been thoroughly investigated, our understanding of oral somatosensory perception remains limited. Further, assessing and measuring individual differences in oral somatosensory perception pose notable challenges. This review aimed to evaluate the existing methods to assess oral somatosensory perception by examining and comparing the strengths and limitations of each method. The review highlighted the lack of standardized assessment methods and the various procedures within each method. Tactile sensitivity can be assessed using several methods, but each method measures different tactile dimensions. Further investigations are needed to confirm its correlation with texture sensitivity. In addition, measuring a single textural attribute may not provide an overall representation of texture sensitivity. Thermal sensitivity can be evaluated using thermal-change detection or temperature discrimination tests. The chemesthetic sensitivity tests involve either localized or whole-mouth stimulation tests. The choice of an appropriate method for assessing oral somatosensory sensitivity depends on several factors, including the specific research objectives and the target population. Each method has its unique intended purpose, strengths, and limitations, so no universally superior approach exists. To overcome some of the limitations associated with certain methods, the review offers alternative or complementary approaches that could be considered. Researchers can enhance the comprehensive assessment of oral somatosensory sensitivity by carefully selecting and potentially combining methods. In addition, a standardized protocol remains necessary for each method.

The tortuous course of the anterior ethmoidal artery in the orbit: A cadaveric study

AimThe study aimed to define the coursing pattern of the anterior ethmoidal artery (AEA) in the orbit to minimize complications during endoscopic interventions. Materials and methodsA total of ten formalin-fixed cadaveric halves were included in the study. Orbital regions were shown with a superior approach. The superior rectus and superior oblique muscles, as well as the connective tissue and vessels were removed to observe the path of the anterior ethmoidal artery. Measurements such as the width of the artery, the anterior-posterior length of the U formation, the length of the intraorbital part of the ophthalmic artery, and the distance of the AEA from its opthalmic origin to the anterior ethmoidal foramen were made. ResultsTen of the AEAs originated from the ophthalmic artery. The AEA branches originated from the ophthalmic artery approximately 18.4 mm after the orbital artery entered the orbital, and the mean width of the AEAs was 0.82 mm. In seven of the total anterior ethmoidal arteries, they coursed in the intraethmoidal cavities below the cranial base. The mean distance from the origin of AEAs to the medial wall of the orbit was 4.9 mm. After leaving the ophthalmic artery, seven of the AEAs were coursing forward and turned back ('U' turn formation), which have proximately 1.5 mm in anteroposterior direction. ConclusionThe anterior ethmoidal artery is 0.8 mm wide, originates from the distal part of the ophthalmic artery, entering the orbit after a 1.5 mm U-turn.

Microsurgical anatomy and approaches to thalamic gliomas. Part 1: A cartography guide for navigating to the thalamus. Integrating 3D model rendering with anatomical dissections.

The selection of appropriate microsurgical approaches to treat thalamic pathologies is currently largely subjective. The objective of this study was to provide a structured cartography map for surgical navigation to treat gliomas involving different surfaces of the thalamus. Fifteen formalin-fixed, silicone-injected cadavers (30 sides) were dissected, and 10 adult brain specimens (20 sides) were used to illustrate thalamic microsurgical anatomy using the Klingler fiber dissection technique. Exposures and trajectories for the six most common microsurgical approaches were depicted using MR data from healthy subjects converted into surface-rendered 3D virtual brain models. Additionally, thalamic surfaces exposed with all six approaches were color mapped on the virtual 3D model and compared side-by-side in 360° views with previously reported microsurgical approaches. These 3D models were then used in conjunction with topographic data to guide cadaveric dissection steps. There are two general surgical routes to thalamic lesions: the subarachnoid transcisternal and transcortical routes. The transcisternal route consists of the following three approaches: 1) anterior interhemispheric transcallosal approach, which exposes the anterior and superior thalamus; 2) posterior interhemispheric transcallosal approach, which exposes the posterosuperior thalamus; and 3) supracerebellar infratentorial approach, which exposes the posteromedial cisternal thalamus and can be extended laterally to approach the posterolateral thalamus by cutting the tentorium. The three transcortical approaches are the 1) superior parietal lobule approach, which exposes the posterosuperior thalamus and is particularly advantageous in the setting of hydrocephalus; 2) transtemporal gyrus approach, which exposes the inferolateral thalamus; and 3) transsylvian transinsular approach, which exposes the lateral thalamus (slightly more superiorly and posteriorly) and is advantageous for pathologies extending laterally into the peduncle, lenticular nucleus, or insula. Microsurgical approaches to thalamic gliomas continue to be challenging. Nonetheless, safe and effective cisternal, ventricular, and cortical corridors can be developed with thoughtful planning, anatomical understanding, and knowledge of the advantages, risks, and limitations of each approach. In some cases, it is wise to combine these approaches with staged procedures, as the authors demonstrate in Part 2. In Part 1 of this two-part series, they discuss thalamic microsurgical anatomy and illustrate the trajectory and exposures of all six approaches to guide decision-making. Part 2 discusses their thalamic glioma microsurgical case series, which utilizes these microsurgical approaches.

Exploring the Potential of Deep Learning and Blockchain for Intrusion Detection Systems: A Comprehensive Review

Detecting intrusions in real-time within cloud networks presents a multifaceted challenge involving intricate processes such as feature representation, intrusion type classification and post-processing procedures. Distributed Intrusion Detection Systems (DIDSs) constitute a complex landscape characterized by diverse contextual nuances, distinct functional advantages and limitations specific to deployment scenarios. Despite these challenges, DIDS offers immense potential for addressing evolving intrusion detection challenges through tailored contextual adaptations and unique functional advantages. Moreover, exploring the limitations associated with different deployment contexts facilitates targeted improvements and refinements, unlocking new avenues for innovation in intrusion detection technologies. Notably, deep learning (DL) integrated with blockchain technology emerges as a superior approach in terms of security, while bioinspired models excel in Quality of Service (QoS). These models demonstrate higher accuracy across various network scenarios, underscoring their efficacy in intrusion detection. Additionally, edge-based models exhibit high accuracy and scalability with reduced delay, complexity and cost in real-time network environments. The fusion of these models holds promise for enhancing classification performance across diverse attack types, offering avenues for future research exploration. This text conducts a comprehensive comparison of performance metrics, including accuracy, response delay, computational complexity, scalability and deployment costs. The proposed Novel DIDS Rank (NDR) streamlines model selection by considering these metrics, enabling users to make well-informed decisions based on multiple performance aspects simultaneously. This unified ranking approach facilitates the identification of DIDS that achieves high accuracy and scalability while minimizing response delay, cost and complexity across varied deployment scenarios.

Reproductive genetic carrier screening in pregnancy: improving health outcomes and expanding access.

Reproductive genetic carrier screening (RGCS) serves to screen couples for their risk of having children affected by monogenic conditions. The included conditions are mostly autosomal recessive or X-linked with infantile orearly-childhood onset. Cystic fibrosis, spinal muscular atrophy, and hemoglobinopathies are now recommended by the American College of Obstetricians and Gynecologists (ACOG) for universal screening. Recommendations for further RGCS remain ethnicity based. The American College of Medical Genetics and Genomics and the National Society of Genetic Counselors in recent years have recommended universal expanded-panel RGCS and moving towards a more equitable approach. ACOG guidelines state that offering RGCS is an acceptable option, however it has not provided clear guidance on standard of care. Positive results on RGCS can significantly impact reproductive plans for couples, including pursuing invitro fertilization with preimplantation genetic testing, prenatal genetic testing, specific fetal orneonatal treatment, or adoption. RGCS is a superior approach compared to ethnicity-based carrier screening and moves away from single race-based medical practice. We urge the obstetrics and gynecology societies to adopt the guidelines for RGCS put forward by multiple societies and help reduce systemic inequalities in medicine in our new genetic age. Having national societies such as ACOG and theSociety for Maternal-Fetal Medicine officially recommend and endorse RGCS would bolster insurance coverage and financial support by employers for RGCS. The future of comprehensive reproductive care in the age of genomic medicine entails expanding access so patients and families can make the reproductive options that best fit their needs.

Enhancing Forecasting Accuracy in Commodity and Financial Markets: Insights from GARCH and SVR Models

The aim of this study is to enhance the understanding of volatility dynamics in commodity returns, such as gold and cocoa, as well as the financial market index S&P500. It provides a comprehensive overview of each model’s efficacy in capturing volatility clustering, asymmetry, and long-term memory effects in asset returns. By employing models like sGARCH, eGARCH, gjrGARCH, and FIGARCH, the research offers a nuanced understanding of volatility evolution and its impact on asset returns. Using the Skewed Generalized Error Distribution (SGED) in model optimization shows how important it is to understand asymmetry and fat-tailedness in return distributions, which are common in financial data. Key findings include the sGARCH model being the preferred choice for Gold Futures due to its lower AIC value and favorable parameter estimates, indicating significant volatility clustering and a slight positive skewness in return distribution. For Cocoa Futures, the FIGARCH model demonstrates superior performance in capturing long memory effects, as evidenced by its higher log-likelihood value and lower AIC value. For the S&P500 Index, the eGARCH model stands out for its ability to capture asymmetry in volatility responses, showing superior performance in both log-likelihood and AIC values. Overall, identifying superior modeling approaches like the FIGARCH model for long memory effects can enhance risk management strategies by providing more accurate estimates of Value-at-Risk (VaR) and Expected Shortfall (ES). Additionally, the out-of-sample evaluation reveals that Support Vector Regression (SVR) outperforms traditional GARCH models for short-term forecasting horizons, indicating its potential as an alternative forecasting tool in financial markets. These findings underscore the importance of selecting appropriate modeling techniques tailored to specific asset classes and forecasting horizons. Furthermore, the study highlights the potential of advanced techniques like SVR in enhancing forecasting accuracy, thus offering valuable implications for portfolio management and risk assessment in financial markets.

Dendrochronology with a medical X-ray photon counting computed tomography scanner

Dendrochronology traditionally involves invasive techniques that might harm cultural heritage artifacts. Non-invasive approaches using X-ray technology and computed tomography (CT) have emerged, but dedicated CT systems are limited in availability. This study explored the viability of using a recently developed photon counting medical CT scanner for growth ring analysis. Six wood samples from pine, oak and beech with varying growth rates were studied. Comparisons were made between traditional methods and CT scanning with measurements performed on the untreated surface, a prepared surface and on CT images. For samples with annual rings wider than 0.3–0.4 mm, CT scanning performed well, while samples with thinner rings or indistinct ring boundaries presented challenges. The combination of traditional tree-ring measurements and analyses of CT scanned images might be a superior study approach generating extra data and information.

An adaptive coupled control method based on vehicles platooning for intersection controller and vehicle trajectories in mixed traffic

AbstractConnected and autonomous driving technologies offer a novel solution for intersection control optimization. Connected and autonomous vehicles (CAVs) can access signal plans and optimize trajectories to minimize delays and reduce fuel consumption. However, optimizing trajectories for individual vehicles significantly increases complexity, especially for joint optimization of traffic signals and vehicle trajectories. Given the current technical, regulatory, and policy constraints, a superior intersection management approach is necessary before fully automated driving is achieved. This paper introduces an adaptive coupling control (ACC) method based on vehicle platooning to optimize signal timings and vehicle trajectories in mixed traffic. Initially, vehicle platoon segmentation is conducted, led by CAVs. The study then proposes a single‐layer coupled optimization model based on vehicle platoons, simplifying the joint optimization model. To address logistic constraint difficulties, a linearization of the coupled model (LCM) method is developed. Numerical experiments demonstrate that the ACC method significantly reduces vehicle delay and fuel consumption. At high CAV penetration rates (0.8 < R <1) and high traffic volumes (over 900 pcu/h), vehicle platoon control delivers excellent performance, with delays and fuel consumption even lower than in a fully automated environment (R = 1). This surprising result suggests that the mixed platoon system (ACC method) positively impacts mixed traffic.

Cross-Education of Skill: Assessment of Overhand Throwing Using Product- and Process-Oriented Assessment

ABSTRACT Purpose: The aims of the present study were to: (1) investigate the magnitude and direction of the cross-education effect in a unilateral sport skill (overhand throw) and (2) to establish which practice condition (dominant hand only or alternating hands) would yield the best results. Methods: The study involved three experimental groups of 11-year-old children (n = 59). The first group (n = 20) used only the dominant hand to throw the ball. The second group (n = 19) used the nondominant hand only, while the third (n = 20) alternated hands for each throw. A pre- and post-testing of both hands preceded and followed the intervention period. Results: The results of our study revealed no asymmetry in cross-education effect between the limbs for children’s overhand ball throwing. It was also shown that training both hands is superior to training the dominant hand alone. Conclusion: Our findings would be of particular interest to physical education teachers and coaches of unilateral sports who are advised to review their unilateral skill teaching methods as bilateral training offers a superior approach to augmenting the process of motor learning and performance.

Enhanced peroxymonosulfate activation by δ-MnO2 nanocatalyst enriched with oxygen vacancies for phenolic pollutants polymerization

Heterogeneous advanced oxidation processes technology holds great potential for the removal of toxic phenolic molecules in water, but is currently challenged by overuse of oxidation agents and undesirable carbon emissions during the mineralization process. The present work demonstrates that with an oxygen-vacancy-rich Fe doped δ-phase MnO2 (δ-MnO2) as the nanocatalyst, the phenol (PhOH) could be removed with high selectivity as well as effective conversion into non-toxic phenolic polymers via a non-radical electron transfer route, instead of complete mineralization by common radical attacking route. Oxygen vacancies in δ-MnO2 were enriched by Fe doping, which greatly improved the activation of peroxymonosulfate (PMS) by extending the length of the O-O bond in PMS. A 6.68-fold enhancement of the removal rate of PhOH was achieved by Fe doping δ-MnO2, compared to the pristine δ-MnO2. Moreover, the consumption of PMS could be reduced by up to 95.08 %, and the carbon emissions were also reduced by up 99.13 % during the polymerization process. The present study manifests that rationally designing a non-radical route offers significant potential for the cost-effective use of oxidation agents as well as reducing carbon emissions, presenting a superior approach for the target of achieving carbon neutrality in environmental remediation.

Endoscopic Transpterygoid Approach to Meckel’s Cave: Technical Considerations and Retrospective Analysis of a Clinical Series

ObjectiveTumors located within the Meckel's cave (MC) pose a significant surgical challenge. Although several corridors to access this complex region have been described, the endoscopic transpterygoid approach (ETPA) and the endoscopic transorbital superior eyelid approach (ETOA) have emerged in recent years, as viable alternatives to traditional microsurgical transcranial approaches (MTA). To date, there is a limited literature on surgical series considering endoscopic-assisted approaches to the MC. MethodsWe conducted a retrospective analysis of patients with primary MC tumors treated at our Institution between 2015 and 2022, specifically those managed via the ETPA assisted by intraoperative Endoscopic Diving Technique (EDT). Lesion resection extent was evaluated using pre- and post-intervention radiological images and surgical videos. Moreover, a literature review on ETPA was performed. ResultsThis series comprises 7 patients affected by 4 trigeminal schwannomas, 1 benign notochordal cell tumor, 1 dermoid cyst and 1 mesenchymal tumor. In 71 % of cases, trigeminal neuralgia was the presenting symptom. Post-operative clinical improvement was observed in all but one case. Notably, 85.7 % of patients achieved total or near-total resection (NTR), with the remaining case undergoing subtotal resection (STR). No significant intraoperative complications occurred, and no recurrences were observed during the mean follow-up period of 41 months. ConclusionsIn selected cases, the ETPA offers a direct and safe path to lesions located into the MC. This approach circumvents complications and constraints associated with ETOA or MTA. Moreover, the use of the EDT reduces manipulation of critical neurovascular structures, enhancing the efficacy of the ETPA.

Keeping classical distinguisher and neural distinguisher in balance

At CRYPTO 2019, Gohr pioneered the use of the neural distinguisher (ND) for differential cryptanalysis, sparking growing interest in this approach. However, a key limitation of ND is its inability to analyze as many rounds as the classical differential distinguisher (CD). To overcome this, researchers have begun combining ND with CD into a classical-neural distinguisher (CND) for differential cryptanalysis. Nevertheless, the optimal integration of CD and ND remains an under-studied and unresolved challenge.In this paper, we introduce a superior approach for constructing the (r+s)-round differential distinguisher CNDr+s by keeping the r-round classical distinguisher CDr and the s-round neural distinguisher NDs in balance. Through experimental analysis, we find that the data complexity of CNDr+s closely approximates the product of that for CDr and NDs. This finding highlights the limitations of current strategies. Subsequently, we introduce an enhanced scheme for constructing CNDr+s, which comprises three main components: a new method for searching the suitable differential characteristics, a scheme for constructing the neural distinguisher, and an accelerated evaluation strategy for the data complexity of CNDr+s. To validate the effectiveness of our approach, we apply it to the round-reduced Simon32, Speck32 and Present64, achieving improved results. Specifically, for Simon32, our CND12 and CND13 exhibit data complexities of 216 and 221, respectively, whereas CND12 in prior work required a data complexity of 222. In the case of Speck32, Our scheme reduce the data complexity of CND9 form 220 to 218. For Present64, We construct CND8 with a data complexity of 213, a significant improvement over the classical distinguisher of 232. These results demonstrate the superiority of our scheme.

A superior approach? The role of robotic sleeve gastrectomy in patients with super super obesity using the 2019-2022 MBSAQIP database.

Laparoscopic sleeve gastrectomy (LSG) in patients with BMI ≥ 60 presents technical challenges, that might be overcome by robotic surgery, but its effectiveness has not been rigorously evaluated. We compared the 30-day outcomes of LSG and robotic sleeve gastrectomy (RSG) in patients with BMI < 60 versus ≥ 60 and between LSG and RSG in patients with BMI ≥ 60. Patients aged 18-65 years who underwent sleeve gastrectomy were included using the 2019-2022 MBSAQIP database. We performed a Propensity Score Matching analysis, with 21 preoperative characteristics. We compared 30-day postoperative outcomes for patients with BMI < 60 versus ≥ 60 using either a laparoscopic (Analysis 1) or robotic approach (Analysis 2) and compared LSG versus RSG in patients with BMI ≥ 60 (Analysis 3). 297,250 patients underwent LSG and 81,008 RSG. Propensity-matched¸ outcomes in analysis 1 (13,503 matched cases), showed that patients with BMI ≥ 60 had higher rates of mortality (0.1% vs. 0.0%, p=0.014), staple line leak (0.3% vs. 0.2%, p=0.035), postoperative bleeding (0.2% vs 0.1%, p=0.028), readmissions (3.5% vs. 2.4%, p<0.001), and interventions (0.7% vs. 0.5%, p=0.028) when compared to patients with BMI < 60. In analysis 2 (4350 matched cases), patients with BMI ≥ 60 demonstrated longer operative times, length of stay, and higher rates of unplanned ICU when compared to patients with BMI < 60. In analysis 3 (4370 matched cases), patients who underwent RSG had fewer readmissions (2.9% vs. 3.7%, p=0.037), staple line leaks (0.1% vs. 0.3%, p=0.029), and postoperative bleeding (0.1% vs. 0.3%, p=0.045), compared to LSG. Conversely, a longer operative time (92.74 ± 38.65 vs. 71.69 ± 37.45 min, p<0.001) was reported. LSG patients with BMI ≥ 60 have higher rates of complications compared to patients with a BMI < 60. Moreover, some outcomes may be improved with the robotic approach in patients with BMI ≥ 60. These results underscore the importance of considering a robotic approach in this super super obese population.

Surgical repair of posttraumatic injuries of the scapholunate ligament: A literature study.

Scapholunate interosseous ligament rupture can cause wrist issues like pain, strength loss, and cartilage degeneration. While various surgical treatments exist, it's unclear which method is optimal. This study aims to determine the superior treatment approach for scapholunate dissociation. In Pubmed, Embase, Scopus and Web of Science was searched for articles reporting results of surgical repair of scapholunate dissociation. Additional inclusion criteria were English- and Dutch-language articles published between January 2000 and December 2022 with at least 8 patients and at least 1 year of follow-up. Seventeen articles were included, 9 covered tenodesis repair, 2 focused on capsulodesis, 3 on direct scapholunate ligament repair using bone anchors, and 3 on a combination of tenodesis and capsulodesis. No difference could be found between the types of surgical techniques in wrist mobility and grip strength. The Disability of Arm, Shoulder, and Hand score, Visual Analogue Scale for pain and Mayo wrist scores showed no clinically relevant difference. With all methods, normal radiological values were obtained after surgery. The mean scapholunate angle was less than 60° and the scapholunate gap less than 3 mm. However, at longer follow-up an increase in this angle and gap was seen again. This review did not allow to conclude that one technique was better than another to treat scapholunate dissociation because of poor quality of the included studies. Pre- and postoperative values were not always reported, there were insufficient comparative studies, and randomized prospective studies were missing.

Neonatal streptozotocin induced diabetic rat models: A superior approach to mimicking human type 2 diabetes

Neonatal streptozotocin induced diabetic rat models: A superior approach to mimicking human type 2 diabetes

Megakaryocytic IGF1 coordinates activation and ferroptosis to safeguard hematopoietic stem cell regeneration after radiation injury.

Hematopoietic stem cell (HSC) regeneration underlies hematopoietic recovery from myelosuppression, which is a life-threatening side effect of cytotoxicity. HSC niche is profoundly disrupted after myelosuppressive injury, while if and how the niche is reshaped and regulates HSC regeneration are poorly understood. A mouse model of radiation injury-induced myelosuppression was built by exposing mice to a sublethal dose of ionizing radiation. The dynamic changes in the number, distribution and functionality of HSCs and megakaryocytes were determined by flow cytometry, immunofluorescence, colony assay and bone marrow transplantation, in combination with transcriptomic analysis. The communication between HSCs and megakaryocytes was determined using a coculture system and adoptive transfer. The signaling mechanism was investigated both in vivo and in vitro, and was consolidated using megakaryocyte-specific knockout mice and transgenic mice. Megakaryocytes become a predominant component of HSC niche and localize closer to HSCs after radiation injury. Meanwhile, transient insulin-like growth factor 1 (IGF1) hypersecretion is predominantly provoked in megakaryocytes after radiation injury, whereas HSCs regenerate paralleling megakaryocytic IGF1 hypersecretion. Mechanistically, HSCs are particularly susceptible to megakaryocytic IGF1 hypersecretion, and mTOR downstream of IGF1 signaling not only promotes activation including proliferation and mitochondrial oxidative metabolism of HSCs, but also inhibits ferritinophagy to restrict HSC ferroptosis. Consequently, the delicate coordination between proliferation, mitochondrial oxidative metabolism and ferroptosis ensures functional HSC expansion after radiation injury. Importantly, punctual IGF1 administration simultaneously promotes HSC regeneration and hematopoietic recovery after radiation injury, representing a superior therapeutic approach for myelosuppression. Our study identifies megakaryocytes as a last line of defense against myelosuppressive injury and megakaryocytic IGF1 as a novel niche signal safeguarding HSC regeneration.

Postoperative Complications of Laparoscopic versus Open Varicocelectomy

Background: Varicocele, characterized by the dilation and swelling of testicular veins, significantly impacts male infertility and semen quality, affecting 10-15% of the male population. Surgical intervention is essential to alleviate these effects, with various techniques available, including laparoscopic and open subinguinal varicocelectomy. Objective: This study aimed to compare postoperative complications between laparoscopic and open subinguinal varicocelectomy to determine the superior approach in terms of patient outcomes and complications. Methods: A randomized controlled trial was conducted, involving 130 patients admitted to Hayatabad Medical Complex, Peshawar, from November 10, 2021, to July 31, 2022. Participants, presenting with symptoms of scrotal heaviness, testicular swelling, pain, and infertility, were randomly assigned to either the laparoscopic (Group L, n=70) or open subinguinal (Group O, n=60) varicocelectomy groups. Preoperative assessments included medical history, clinical examination, and necessary tests. Informed consent was obtained from all participants. Exclusion criteria included patients with malignancy, diabetes (BSR &gt; 200 mg/dl), or unstable hemoglobin levels (Hb &lt; 10 mg/dl). Postoperative complications, including wound erythema, hydrocele, epididymitis, and bruising, were documented and analyzed using SPSS version 25, with a significance level set at P ≤ 0.05. Results: The mean age of Group L was 27.3 years (±2.3), and Group O was 25.2 years (±3.5) (P = 0.042). Postoperative complications were significantly lower in Group L compared to Group O. Wound erythema was observed in 1.42% of Group L and 8.3% of Group O (P = 0.05). Hydrocele occurred in 2.8% of Group L versus 10% of Group O (P = 0.04). Epididymitis was found in 1.42% of Group L and 6.5% of Group O (P = 0.03). Bruising was noted in 1.66% of Group O, with no cases in Group L (P = 0.05). Conclusion: Laparoscopic varicocelectomy resulted in fewer postoperative complications compared to open subinguinal varicocelectomy, making it the preferred surgical approach for varicocele treatment. Further studies with larger sample sizes and long-term follow-up are recommended to validate these findings.