Terms Of Leakage Research Articles

Analytical Solutions for Groundwater Response to Earth Tides in Thick Semiconfined Aquifers

AbstractThe tidal behavior of a well in semiconfined aquifers can be described by a diffusion equation including a leakage term. This approach is valid for thin aquifers, as long as the aquitard has low permeability relative to the aquifer. However, in cases where the aquifer is thick and the permeability of the aquitard is not low, using the existing solutions based on these approximations leads to unsatisfactory outcomes. Alternative solutions for both vertical and horizontal wells were obtained by solving the standard diffusion equation, with leakage expressed as a boundary condition. The solutions can be used to estimate any one of wellbore storage coefficient, skin effect, hydraulic diffusivity, and vertical leakage, given the other three. Furthermore, a nondimensional number, named hydraulic Biot number, was derived mathematically, which forms the basis for a quantitative criterion to assess the applicability of existing solutions. In the case of a vertical well, the existing solution exhibits acceptable error only if the hydraulic Biot number is less than 0.245. The new solution extends this upper limitation to 0.475. However, when the number is greater than 0.475, both the existing solution and new solution are invalid due to the invalid uniform flowrate assumption. For a horizontal well, when the number is less than 0.245, the existing solution is suitable with acceptable error. Our new solution effectively overcomes this limitation. Finally, the new solution was applied to the case of the Arbuckle aquifer to demonstrate the improved validity of the new solution compared to the existing one.

Adaptive control of bilateral teleoperators with convergent parameter estimation and guaranteed compliance

Although adaptive control has been studied for teleoperation systems in the past decades, the convergence of parameter estimation is generally difficult to claim in the existing methods, and thus only specific scenarios (e.g., free motion) and partial operation performance (e.g., synchronization) have been addressed. In this paper, we found that the convergence of parameter estimation is crucial for bilateral teleoperation systems to retain the guaranteed operation performances, including compliance in the tracking motion and transparency in the contact motion. Accordingly, this paper suggests an alternative adaptive control for bilateral teleoperation systems, where a new adaptive law with the estimation errors as leakage terms is developed to obtain finite-time convergence of the parameter estimation. This convergent property allows to compensate for the undesired dynamics (e.g., gravity) in the closed-loop system so as to achieve ideal compliance and transparency. The control system’s stability and performances under constant time delays are analyzed for three scenarios: free motion, tracking motion, and contact motion. The quantitative relationship between the joint velocities and the human torques in the tracking motion is also studied, and the transparency is addressed in the contact motion. Simulations and experiments on a Baxter robot all showcase the effectiveness and superiority of the developed approach.

The Extended Diamond Difference - Constant Nodal Method with Decoupled Cell Iteration Scheme in Two-Dimensional Discrete Ordinate Transport Problems

Analytical solutions for the Boltzmann transport equation are typically limited to specific scenarios, prompting the research transport community to extensively explore numerical approaches with special attention to the discrete ordinates (SN) formulation. The spectral nodal methods are widely recognized for their capability to preserve the analytical solution of the SN mathematical model. However, these formulations exhibit notable complexity with high-order polynomial approximations for the transverse leakage terms, motivating researchers to pursue simpler hybrid approaches by partially preserving the analytical solution. Both spectral nodal and hybrid spectral nodal methods introduce nonstandard auxiliary equations not amenable to standard iterative schemes due to a highly coupling in angular directions. Following these ideas, we present a finite element – spectral nodal hybrid method referred to as Extended Diamond Difference-Constant Nodal (EDD-CN) method for two-dimensional fixed-source discrete ordinate transport problems with constant nodal approximation for the leakage terms. The proposed method seeks to preserve eigenfunctions associated with the dominant pair of eigenvalues in the transverse integrated SN equations. In addition, we propose a novel iterative scheme called Decoupled Cell Iteration (DCI) scheme which decouples the angular directions in the nonstandard auxiliary equations and follows conventional iteration transport sweeps for solving SN problems.

Exponentially Synchronous Results for Delayed Neural Networks With Leakage Delay via Switched Delay Idea and AED-ADT Method.

Time delay has always been one of the main factors affecting the application performance of neural network (NN) systems, and dynamic performance research of NNs with time delays has been the focus of many scholars in recent years. This article enquires into the exponentially synchronous problem of switched delayed NNs with time delay in the leakage term. Adopting an unusual form from a common switched system, the switching modes of the switched delayed NNs system in this article are dependent on time delays. In the first place, the master, slave, and error NNs models are reconstructed into the switched form by introducing the switched delay idea. Then with the help of the admissible edge-dependent average dwell time (AED-ADT) method and delay-dependent switching adjustment indicators, a novel set of generalized delay-mode-dependent multiple Lyapunov-Krasovskii functionals (MLKFs) is built for analyzing the cases where a state-feedback controller exists and does not exist in the model, and where parts of LKFs may increase during the period when the corresponding subsystems are activated. For these cases, several effective exponential synchronization criteria and switching laws are presented accordingly. At last, the verification of the theoretical results is shown through a few examples.

Tightening Leakage Resilience of the Suffix Keyed Sponge

Lightweight cryptographic constructions are often optimized on multiple aspects that put the security bounds to the limit. In this respect, it is important to obtain security bounds that are tight and give an accurate and exact indication of the generic security. However, whereas for black-box security bounds it has become common practice to argue tightness of security bounds, for leakage resilience security bounds this is not the case. This is unfortunate, as for leakage resilience results, tightness is even more important as there is already a lossiness incurred in capturing the actual leakage by a theoretical model in the first place.In this work, we consider the SuKS (Suffix Keyed Sponge) PRF construction and investigate tightness of the leakage resilience bound of Dobraunig and Mennink (ToSC 2019). We observe that, although their black-box security result is tight, their leakage resilience bound is not tight in their bounded leakage term λ. We observe that this is caused by the fact that parts of the security bound contain a term covering multicollisions and a term covering leakage, but an adversary is unable to combine both. We next consider improved security of the SuKS for two types of leakage: fixed position leakage, where the adversary directly learns the value of λ bits of a secret state, and Hamming weight leakage, where the Hamming weight of a fixed part of the state is leaked. For fixed position leakage, a very generous form of bounded leakage, we improve the original bound by making wise use of the multicollision limit function of Daemen et al. (ASIACRYPT 2017). For the more realistic setting of Hamming weight leakage, we structurally revisit the multicollision limit function analysis by including Hamming weight in the computation, a problem that is difficult on its own due to the non-uniform character of this type of leakage. In both cases, we improve and tighten the leakage resilience bound of Dobraunig and Mennink. The improved bound for the SuKS has immediate consequences for the leakage resilience of the NIST lightweight cryptography competition finalist ISAP v2, an authenticated encryption scheme that uses the SuKS internally.

Is proctoscopy sufficient for the evaluation of colorectal anastomosis prior to ileostomy reversal? A nationwide retrospective analysis of the Italian Society of Surgical Oncology Colorectal Cancer Network Collaborative group (SICO-CCN).

Several methods for assessing anastomotic integrity have been proposed, but the best is yet to be defined. The aim of this study was to compare the different methods to assess the integrity of colorectal anastomosis prior to ileostomy reversal. A retrospective cohort analysis on patients between 1 January 2010 and 31 December 2020 with a defunctioning stoma for middle and low rectal anterior resection was performed. A propensity score matching comparison between patients who underwent proctoscopy alone and patients who underwent proctoscopy plus any other preoperative method to assess the integrity of colorectal anastomosis prior to ileostomy reversal (transanal water-soluble contrast enema via conventional radiology, transanal water-soluble contrast enema via CT, and magnetic resonance) was performed. The analysis involved 1045 patients from 26 Italian referral colorectal centres. The comparison between proctoscopy alone versus proctoscopy plus any other preoperative tool showed no significant differences in terms of stenoses (p = 0.217) or leakages (p = 0.103) prior to ileostomy reversal, as well as no differences in terms of misdiagnosed stenoses (p = 0.302) or leakages (p = 0.509). Interestingly, in the group that underwent proctoscopy and transanal water-soluble contrast enema the comparison between the two procedures demonstrated no significant differences in detecting stenoses (2 vs. 0, p = 0.98), while there was a significant difference in detecting leakages in favour of transanal water-soluble contrast enema via CT (3 vs. 12, p = 0.03). We can confirm that proctoscopy alone should be considered sufficient prior to ileostomy reversal. However, in cases in which the results of proctoscopy are not completely clear or the surgeon remains suspicious of an anastomotic leakage, transanal water-soluble contrast enema via CT could guarantee its detection.

Compacting the core of a commercial high-power lead-cooled fast reactor

Two options for the layout of a fast reactor with lead coolant are being considered. The design of the fuel assemblies and core fuel rods is identical to the BREST-OD-300 reactor. One of the layouts is traditional with a flattened core. The other layout is the most compact. It has an elongated core and is characterized by an optimal ratio of core diameter to height in terms of minimal neutron leakage. The electric capacity of the first of them is about 2.9 GW, the second - 13.3 GW. The second layout is a high-temperature reactor. When operating at rated power, the maximum coolant temperature reaches 1631 K. The use of cermets fuel based on UN-PuN mononitride micrograins and uranium metal nanopowder, coolant based on lead thorium ores and tungsten fuel rod coatings made it possible to ensure the safety of reactors in emergency modes such as "anticipated transients without scram". A distinctive feature of the layouts is to reduce the danger of emergency modes when they are applied simultaneously. In all emergency modes, large reserves are maintained up to the maximum permissible temperatures of fuel, coolant and structural materials.

Exponential Response Matrix Spectral Nodal Method for the Discrete Ordinates Neutral Particle Transport Model

In this work, the response matrix‐exponential nodal method is presented to solve fixed source neutral particle transport problems with isotropic scattering and discrete ordinates formulation in two‐dimensional Cartesian geometry. The method is based on the response matrix scheme by using the general solution of the transverse integrated SN nodal equations with exponential approximations for the leakage terms. This approach eliminates the need for additional auxiliary equations found in the spectral Green’s function (SGF) schemes, streamlining internodal computation to a matrix‐vector multiplication. The formulation includes a lambda parameter possible determined by the medium characteristics, e.g., the scattering ratio coefficient and/or empirical methods. Two model problems with low absorption rates were investigated to analyze the performance of the proposed method. The numerical solutions exhibited superior accuracy for the coarsest spatial grid configurations in both homogeneous and heterogeneous study cases. However, refining the spatial grid revealed a relative loss in accuracy compared to the RM‐CN method, potentially due to increased truncation error propagation. Nevertheless, all numerical solutions converge to the reference solution when refining the spatial discretization grid. Comparison of both response matrix schemes demonstrated similar convergence rates and computational efficiency in terms of iterations and CPU consumption.

Assessment of Computational Technicalities for 2D/1D Coupling Method and Its Comparison with 3D MOC

The 2D/1D coupling method is recognized as one of the preferred high‐fidelity calculation methods for reactors featured with well homogeneity in the axial direction. However, the choices of the technicalities, such as transverse leakage, axial solver, and transverse leakage splitting method, will lead to different calculational performance. This paper outlines the theory of the 2D/1D coupling method and describes the detailed implementations of the key technicalities. Based on numerical tests, the choices of the related calculational parameters are analyzed, such as the order of the quadrature set, ray spacing, and the axial mesh size. Then, the computational performance of six typical 2D/1D technicalities is compared and assessed. A comparison between 2D/1D coupling method and direct 3D MOC calculation is also made. For the transverse leakage, the Fourier expansion technique could significantly reduce the memory burden and computational cost, but with the similar accuracy as the anisotropic leakage term. It is recommended to use the axial DGFEM SN solver, which has better consistency and leads to higher computational efficiency. Additionally, the results also show that the 2D/1D coupling method can appropriately increase the axial mesh size, which only has slight effect on the accuracy. For nuclear reactors featured with nonstrong heterogeneity in axial direction, the 2D/1D coupling method has significant advantages than the direct 3D MOC calculation.

Stability Analysis and Almost Periodic Solutions for Quaternion-Valued Cellular Neural Networks with Leakage Term on Time Scales

Stability Analysis and Almost Periodic Solutions for Quaternion-Valued Cellular Neural Networks with Leakage Term on Time Scales

Comparison of clinical and radiological outcomes of vertebral body stenting versus percutaneous kyphoplasty for the treatment of osteoporotic vertebral compression fracture: A systematic review and meta-analysis.

The study aimed to compare the efficacy and safety of percutaneous kyphoplasty (PKP) and vertebral body stenting (VBS) in the treatment of osteoporotic vertebral compression fractures (OVCFs) and evaluate the clinical efficacy, Cobb angle correction, and cement leakage associated with both methods for OVCFs. A systematic search was conducted in PubMed, EMBASE, Cochrane Library, Medline, China National Knowledge, and Wanfang Data for clinical studies comparing VBS with PKP for OVCF up to May 2023. The meta-analysis was performed using Review Manager 5.3, with a focus on evaluating clinical and radiologic outcomes. A total of eight eligible clinical studies were included in this meta-analysis. In terms of clinical outcomes, VBS was found to have a longer surgical time compared to PKP (standard mean difference [SMD]=1.06 min; 95% confidence interval [CI]: 0.20, 1.92; p=0.02). However, VBS demonstrated comparable blood loss to PKP (SMD =0.00 mL; 95% CI: -0.45, 0.45; p=0.99). Additionally, VBS showed slight superiority in alleviating back pain as measured by the Visual Analog Scale (VAS) (SMD=-0.38; 95% CI: -0.63, -0.12; p=0.004), as well as in improving functional disability based on the Oswestry Disability Index (ODI) (SMD= -0.28; 95% CI: -0.54, -0.03; p=0.03). Radiographically, VBS achieved better Cobb angle correction compared to PKP (SMD= -1.00; 95% CI: -1.48, -0.51; p<0.0001), while there was no significant difference in cement leakage between VBS and PKP (odds ratio=0.81; 95% CI: 0.21, 3.14; p=0.76). The findings suggest that VBS has a comparable clinical outcome to PKP based on operation time, intraoperative blood loss, VAS, and ODI. Furthermore, VBS showed slightly better maintenance of Cobb angle correction, whereas VBS did not demonstrate a significant advantage over PKP in terms of cement leakage.

A novel block-chain based secure cross-domain interaction approach for intelligent transportation systems

In the Intelligent Transportation System (ITS), secure and efficient data communication among vehicles, road testing equipment, computing nodes, and transportation agencies is important for building a smart city integrated transportation system. However, the traditional centralized processing approach may face threats in terms of data leakage and trust. The use of distributed, tamper-proof blockchain technology can improve the decentralized storage and security of data in the ITS network. However, the cross-trust domain devices, terminals, and transportation agencies in the heterogeneous blockchain network of the ITS still face great challenges in trusted data communication and interoperability. In this paper, we propose a heterogeneous cross-chain interaction mechanism based on relay nodes and identity encryption to solve the problem of data cross-domain interaction between devices and agencies in the ITS. First, we propose the ITS cross-chain communication framework and improve the cross-chain interaction model. The relay nodes are interconnected through LibP2P to form a relay node chain, which is used for cross-chain information verification and transmission. Secondly, we propose a relay node secure access scheme based on identity-based encryption (IBE) to provide reliable identity authentication for relay nodes. Finally, we build a standard cross-chain communication protocol and cross-chain transaction lifecycle for this mechanism. We use Hyperledger Fabric and FISCO BCOS blockchain to design and implement this solution, and verify the feasibility of this cross-chain interaction mechanism. The experimental results show that the mechanism can achieve a stable data cross-chain read throughput of 2,000 transactions per second (TPS), which can meet the requirements of secure and efficient cross-chain communication and interaction among heterogeneous blockchains in the ITS, and has high application value.

Mitral Kapak Replasmanında Sütür Tekniklerinin Karşılaştırmalı Değerlendirilmesi: Klinik Sonuçlar Üzerindeki Etkisi

Background: This study aimed to compare the outcomes of mitral valve replacement (MVR) using the intermittent simple suture technique versus the horizontal matrix suture technique with pledgeted in terms of paravalvular leakage and infective endocarditis. Methods: A retrospective analysis was conducted on 422 patients who underwent MVR between 2019 and 2023. Patients were divided into two groups based on the suture technique used: group B (simple suture technique) and group P (horizontal matrix suture technique with pledgeted). Propensity score matching was performed to balance the groups, resulting in 62 case pairs for comparative analysis. Results: There were no intraoperative mortalities, and the duration of cardiopulmonary bypass and cross-clamp time did not significantly differ between the two groups. No significant differences were observed in terms of total hospitalization time, early mortality, cerebrovascular events, and arrhythmias. Postoperative echocardiography revealed minimal paravalvular leakage in both groups, with non-serious leakage observed in 4 patients in group B and 2 patients in group P. The incidence of infective endocarditis was 1 in group B and 2 in group P. Hemolysis indicators showed higher mean values in the simple suture technique group, although not statistically significant. Conclusions: The study findings suggest that there is no significant difference in the incidence of paravalvular leak and infective endocarditis between the intermittent simple suture technique and the horizontal matrix suture technique with pledgeted. Both techniques can be safely employed in MVR.

Physiotherapy in Patients with Stress Urinary Incontinence: A Systematic Review and Meta-analysis.

Physiotherapy is the most commonly used treatment for stress urinary incontinence including pelvic floor muscle training, biofeedback, and electrical stimulation. This systematic review evaluated the effects of physiotherapy in patients with stress urinary incontinence compared with no treatment, placebo, sham, surgery, or other inactive control treatments. MEDLINE (via PubMed), The Cochrane Library (CENTRAL), Embase, Scopus, Web of Science, PEDro, and Trip Database were explored using applicable vocabularies for all English and Persian language investigations released from inception to January 2021. On one side, trials including physiotherapy of pelvic floor muscle training, biofeedback, and electrical stimulation and on the other, either no treatment, placebo, sham, surgery, or other inactive control treatments were included. Studies were assessed for appropriateness and methodological excellence. Two authors extracted data. Disagreements were resolved by a third opinion. Data were processed as described in the Joanna Briggs Institute Handbook. Twenty-nine trials with 2601 participants were found, but only 16 were included because of data heterogeneity. The results showed that physiotherapy interventions are better than no treatment in terms of urine leakage, but no difference was found for urinary incontinence severity. Also, physiotherapy showed favorable results over comparison groups for International Consultation on Incontinence Questionnaire, pad test, pelvic floor muscle function, and improvement outcomes. This systematic review supports the widespread use of pelvic physiotherapy as the first-line treatment for adult patients with stress urinary incontinence.

Comparison of Clinical Efficacy Between Da Vinci Robot-Assisted Ivor Lewis Esophagectomy and McKeown Esophagectomy for Middle and Lower Thoracic Esophageal Cancer: A Multicenter Propensity Score-Matched Study.

We compared the perioperative efficacy and safety of da Vinci robot-assisted Ivor Lewis esophagectomy and McKeown esophagectomy for middle and lower thoracic esophageal cancer. A retrospective case-control study method was used. A total of 181 patients with esophageal cancer admitted to three medical centers in China from February 2018 to October 2022 were collected and divided into two groups according to surgical method: da Vinci robot-assisted thoracic surgery (RATS) Ivor Lewis esophagectomy (Ivor Lewis group) and RATS McKeown esophagectomy (McKeown group), respectively. Propensity score matching (PSM) analysis was used to reduce selection bias caused by confounding factors. The perioperative indicators of the two groups were compared and analyzed. There was a statistically significant difference in age and tumor location between the Ivor Lewis group and the McKeown group. After PSM, the above factors were no longer statistically significant. There were 80 patients in each group after PSM. In terms of operative time (P = 0.005), anastomotic leakage (P = 0.029), and pulmonary infection (P = 0.035), the Ivor Lewis group has significant advantages; in terms of the number of lymph nodes dissected around the recurrent laryngeal nerve (P = 0.010), the McKeown group has significant advantages. Both RATS Ivor Lewis esophagectomy and McKeown esophagectomy are safe and effective for treatment of middle and lower thoracic esophageal cancer. Ivor Lewis has advantages in operative time, anastomotic leakage, and pulmonary infection, while McKeown has advantage in lymph node dissection around the recurrent laryngeal nerve.

Adaptive parameter learning and neural network control for uncertain permanent magnet linear synchronous motors

This work aims to achieve accurate parameter estimation and intelligent control of a permanent magnet linear synchronous motor (PMLSM) with unknown parameters, nonlinearities, and disturbances. To address it, we propose a novel adaptive control method composed of a new estimation error-based learning strategy and a neural network (NN)-based adaptive sliding mode controller. An augmented NN with a friction model and a force ripple model is constructed to handle the uncertainties in PMLSM. The proposed learning law that contains leakage terms driven by estimation errors calculates the unknown parameter and NN’s weights online. Especially the gain of the discontinuous term in the learning law is adjusted by the presented update law to reduce the chattering of learned parameters. The controller handles the residual error and external disturbance. Different from the existing methods, the proposed one needs no boundary information of uncertainties in both the controller and parameter-learning strategy. The proposed method is finite-time semi-global uniformly and ultimately bounded (FTSGUUB), which is analyzed by designing a Lyapunov function. Finally, numerical simulations are carried out to validate the parameter learning and control accuracy of the proposed method.

Synchronization of Takagi–Sugeno Fuzzy Time-Delayed Stochastic Bidirectional Associative Memory Neural Networks Driven by Brownian Motion in Pre-Assigned Settling Time

We are devoted, in this paper, to the study of the pre-assigned-time drive-response synchronization problem for a class of Takagi–Sugeno fuzzy logic-based stochastic bidirectional associative memory neural networks, driven by Brownian motion, with continuous-time delay and (finitely and infinitely) distributed time delay. To achieve the drive-response synchronization between the neural network systems, concerned in this paper, and the corresponding response neural network systems (identical to our concerned neural network systems), we bring forward, based on the structural properties, a class of control strategies. By meticulously coining an elaborate Lyapunov–Krasovskii functional, we prove a criterion guaranteeing the desired pre-assigned-time drive-response synchronizability: For any given positive time instant, some of our designed controls make sure that our concerned neural network systems and the corresponding response neural network systems achieve synchronization, with the settling times not exceeding the pre-assigned positive time instant. In addition, we equip our theoretical studies with a numerical example, to illustrate that the synchronization controls designed in this paper are indeed effective. Our concerned neural network systems incorporate several types of time delays simultaneously, in particular, they have a continuous-time delay in their leakage terms, are based on Takagi–Sugeno fuzzy logic, and can be synchronized before any pre-given finite-time instant by the suggested control; therefore, our theoretical results in this paper have wide potential applications in the real world. The conservatism is reduced by introducing parameters in our designed Lyapunov–Krasovskii functional and synchronization control.

Complete Mesocolic Excision (CME) versus Conventional RT Hemicolectomy (CRH) in Patients with Right Sided Colon Cancer: A Systematic Review and Meta-Analysis

Abstract Background We live in an era with improved worldwide average living standards and increased access to adequate healthcare that has considerably improved the diagnosis and treatment of diseases. These measures have had an impact on average life expectancy in most regions of the world. Aim of the Work The aim of this study is to perform a systematic review and meta-analysis to investigate safety and long-term out- comes of Complete Mesocolic Excision (CME) Versus Conventional RT Hemicolectomy (CRH) in patients with right sided colon cancer. Materials and Methods This study is a systematic review and meta-analysis. Literature search, study design, and data analysis were performed following PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. Five medical databases were used in this research: MEDLINE, Cochrane Database of Systematic Reviews, Scopus, Web of Science, and Embase. The keyword was as follows: ―complete mesocolic excision.‖ I select studies published up to December 2020. I select only articles written in English and we did not include abstracts or unpublished data. After literature search, 30 studies have been recorded. Screening by titles and abstracts led to the identification of 20 possibly relevant articles. Of these records, 8 studies were excluded because patients with distal transverse and/or left colon cancer were also evaluated. Moreover, in 3 studies, only the most recently record was selected. Lastly, 8 studies, published between 2010 and 2020, met inclusion criteria. All selected studies were observational; 4 of them were prospective. Overall, 1762 patients were enrolled in qualitative and quantitative analysis, 700 in the CME group and 1062 in the CRH group. Results Postoperative complications were reported in 9 studies showing that no difference was observed between techniques. Six studies separately analyzed surgical and non-surgical postoperative complications. No significant variation was reported between the 2 groups in the 2 different types of complications (surgical complications OR 1.09, 95% CI 0.72–1.63, p = 0.69, no surgical complications OR 1.37, 95% CI 0.79–2.36, p = 0.26, respectively). No significant difference was al- so observed between the two groups in terms of anastomotic leakage, while a significant negative median was reported for intraoperative bleeding in favor of CME group. 4 studies evaluated the procedure time which was significantly shorter for CRH, although heterogeneity levels among studies was high. The analysis of postoperative length of stay showed no difference between the two groups of patients. Number of lymph node yield was reported in 8 studies. The pooled analysis of 1762 patients found a positive median retrieval of 9.17 in CME group. High heterogeneity among the included studies was detected. Seven studies reported data of 3-year OS with a significant OS benefit in CME group. This data was characterized by moderate between-study heterogeneity. Furthermore, 76.4% of patients undergoing CME surgery were alive at 5 years, compared with 68.2% of CRH. Meta-analysis of 3 studies reporting 5-year DFS con- firmed the significant DFS benefit for patients undergoing CME. No significant heterogeneity was observed between the 3 studies. Conclusion My study confirm that CME with CVL associated with D3 lymphadectomy in right-side colon cancer improved not only staging but also prognosis, particularly in II and III stage; CME was a significant independent predictive factor for disease-specific survival at 3 years and 5 years compared with CRH associated with D2 lymphadectomy. CME is a safe and reproducible procedure with acceptable morbi-mortality.

Existence and stability of a periodic solution of a general difference equation with applications to neural networks with a delay in the leakage terms

In this paper, a new global exponential stability criterion is obtained for a general multidimensional delay difference equation using induction arguments. In the cases that the difference equation is periodic, we prove the existence of a periodic solution by constructing a type of Poincaré map. The results are used to obtain stability criteria for a general discrete-time neural network model with a delay in the leakage terms. As particular cases, we obtain new stability criteria for neural network models recently studied in the literature, in particular for low-order and high-order Hopfield and Bidirectional Associative Memory (BAM).

Comparison of metal versus plastic stent for preoperative biliary drainage in patients with pancreatic cancer undergoing neoadjuvant therapy: a meta-analysis and systematic review

BackgroundThis study was performed to compare a metal stent (MS) and plastic stent (PS) in terms of efficacy and complications during neoadjuvant therapy (NAT) and the perioperative period.MethodsWe performed an electronic search of the following databases until 1 June 2022: PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Studies comparing an MS versus PS for PBD in patients with pancreatic cancer undergoing NAT were included.ResultsThe meta-analysis showed that use of an MS was associated with lower rates of reintervention (p < 0.00001), delay of NAT (p = 0.007), recurrent biliary obstruction (RBO) (p = 0.003), and cholangitis (p = 0.03). There were no significant differences between the two groups in terms of stent migration (p = 0.31), postoperative complications (p = 0.20), leakage (p = 0.90), and R0 resection (p = 0.50).ConclusionsUse of an MS for PBD in patients with pancreatic cancer undergoing NAT followed by surgery was associated with lower rates of reintervention, delay of NAT, RBO, and cholangitis compared with use of a PS. However, the postoperative outcomes were comparable between the MS and PS. Further studies on this topic are recommended.