Number Of Nodes Research Articles

Energy efficient routing for improving lifetime in MWSN: A clustering approach

A Mobile wireless sensor network (MWSN) consists of mobile sensor nodes, which can be deployed in any specific environment, and due to its’ mobility it can perform with rapid topological transformations of a network. The sensor nodes having limited battery power are used to collect specific data and this raw data is sent to a static sink node of the network. Under such a scenario, to avoid frequent disconnections due to topological change in the network and can avail more reliable data transmissions in energy awareness perspective, an energy efficient routing protocol for MWSNs to improve its lifetime is proposed here by utilizing a clustering approach. A MWSN with random number of sensor nodes are initially considered and then, clustering algorithm K-means is used to determine a predefined number of clusters with their initial cluster heads (CHs) and centroid locations of these clusters is also determined. The role of these CHs is to elect our DDBLACH (distance to sink and cluster centroid with battery level aware cluster head) nodes from each cluster, by sending and receiving intra-cluster messages among other member sensor nodes. A DDBLACH node is determined by using three factors, such as minimum distance from cluster centroid location, minimum distance from sink and the maximum battery level of the node from each cluster. These DDBLACH nodes are used to collect data from intra-cluster sensors and thereafter, send those towards sink node for further processing using tree-based hierarchical routes. Finally, an energy efficient routing technique for MWSNs is proposed for data transmission from DDBLACH nodes of clusters to sink of the network. Simulation results indicate the superiority of our proposed scheme over other existing methods in various aspects, such as improving more data packet transmission by 14%-23%, presence of alive nodes and subsequently average network lifetime by 5%-24%.

Novel Application of Quantum Computing for Routing and Spectrum Assignment in Flexi-Grid Optical Networks

Flexi-grid technology has revolutionized optical networking by enabling Elastic Optical Networks (EONs) that offer greater flexibility and dynamism compared to traditional fixed-grid systems. As data traffic continues to grow exponentially, the need for efficient and scalable solutions to the routing and spectrum assignment (RSA) problem in EONs becomes increasingly critical. The RSA problem, being NP-Hard, requires solutions that can simultaneously address both spatial routing and spectrum allocation. This paper proposes a novel quantum-based approach to solving the RSA problem. By formulating the problem as a Quadratic Unconstrained Binary Optimization (QUBO) model, we employ the Quantum Approximate Optimization Algorithm (QAOA) to effectively solve it. Our approach is specifically designed to minimize end-to-end delay while satisfying the continuity and contiguity constraints of frequency slots. Simulations conducted using the Qiskit framework and IBM-QASM simulator validate the effectiveness of our method. We applied the QAOA-based RSA approach to small network topology, where the number of nodes and frequency slots was constrained by the limited qubit count on current quantum simulator. In this small network, the algorithm successfully converged to an optimal solution in less than 30 iterations, with a total runtime of approximately 10.7 s with an accuracy of 78.8%. Additionally, we conducted a comparative analysis between QAOA, integer linear programming, and deep reinforcement learning methods to evaluate the performance of the quantum-based approach relative to classical techniques. This work lays the foundation for future exploration of quantum computing in solving large-scale RSA problems in EONs, with the prospect of achieving quantum advantage as quantum technology continues to advance.

Gas exchange in yellow passion fruit hybrids in the Semiarid region

Agronomic characterization and exploitation of the genetic variability in plants of the Passiflora can reveal important genetic resources because the Passiflora species grown under semiarid conditions make important contributions to breeding. The aim of this work was to evaluate the vegetative and physiological characteristics of fifteen yellow passion fruit hybrids in semiarid conditions. The experiment was conducted at IF Baiano – campus Guanambi, Bahia, Brazil. The 15 treatments were 10 genotypes: H09-10; GP09-02; H09-02; H09-14; H09-07; H09-09; FOP09; GP09-03; H09-30; FOP08 from the Active Germplasm Bank of the Genetic Breeding Program of Embrapa Cassava and Fruits, and five commercial hybrids: FB200; FB300; BRS SC; BRGA; BRS Rubi. The treatments were arranged in a randomized block design, with three replications and five observational units per plot. Vegetative characteristics (main branch length, number of functional leaves, number of nodes, and number of flower buds) were measured at full vegetative development, 90 days after transplanting (DAT). Hybrid H09-10 is the earliest in flowering, physiologically more efficient in the morning, closes stomata in the afternoon, regulates transpiration, and has lower leaf temperature, higher photosynthesis rate, and more efficient water use. Gas exchanges and photosynthesis rates, at 300 DAT, vary between hybrids and reading times: photosynthesis is higher in the morning while transpiration is greater in the afternoon. The reduction in carboxylation efficiency is related to non-stomatal factors. Gas exchange variables of the genotypes tend to be directly correlated with the photosynthetically active radiation incident on the leaf

Evaluation of selected rice cultivars' phenotypic traits and chlorophyll content under sub-mergence stress

Currently, rice production in Nigeria is on the increase with the aim of meeting the nation’s need but floods (mainly seasonal) has been among the major factors limiting rice production. Rice is generally a semi aquatic plant well adapted to partially flooded fields but flash flooding may leads to complete submergence there by resulting into huge economic losses mainly due to reduction in gases (hypoxia) and light intensity needed for photosynthesis. The research was conducted at the Biological Garden, Department of Biological Sciences, Federal University Birnin Kebbi. The experiment was set off in a Completely Randomized Design (CRD) consisting of four rice cultivars with control and three replications. Length of internodes, number of nodes per plant, plant height, root length and chlorophyll contents were evaluated using standard methods and protocols. The study analyzed the impact of flooding on rice cultivars, finding significant differences in node number, internode length, plant height, root lengths, and chlorophyll content. The highest number of nodes was found in CP Yartunga, followed by Faro with 6.33 per plant. The highest plant height was 15.50 cm in Faro, while the highest chlorophyll content was 0.41 mg/g in CP 44. The research reveals that rice cultivars recover from flooding stress, with CP Yartunga having the highest number of nodes per plant and Faro having the highest internode length. No significant differences were found in plant height, root length, or chlorophyll content among the evaluated cultivars. Faro had the lowest chlorophyll content. The study reveals that under stress, chlorophyll content in various locations decreases significantly, with a significant drop in recovery and node numbers. Lastly, node recovery is substantial, suggesting lower injury levels. The present study suggests that cultivars like Faro and CP 44 show better resilience, suggesting potential breeding programs focusing on structural traits.

Multi-task Learning for Gaussian Graphical Regressions with High Dimensional Covariates

Gaussian graphical regression is a powerful approach for regressing the precision matrix of a Gaussian graphical model on covariates, which permits the response variables and covariates to outnumber the sample size. However, traditional approaches of fitting the model via separate node-wise lasso regressions overlook the network-induced structure among these regressions, leading to high error rates, particularly when the number of nodes is large. To address this issue, we propose a multi-task learning estimator for fitting Gaussian graphical regression models, which incorporates a cross-task group sparsity penalty and a within-task element-wise sparsity penalty to govern the sparsity of active covariates and their effects on the graph, respectively. We also develop an efficient augmented Lagrangian algorithm for computation, which solves subproblems with a semi-smooth Newton method. We further prove that our multi-task learning estimator has considerably lower error rates than the separate node-wise regression estimates, as the cross-task penalty enables borrowing information across tasks. We examine the utility of our method through simulations and an application to a gene co-expression network study with brain cancer patients.

Kinematic Constrained RRT Algorithm with Post Waypoint Shift for the Shortest Path Planning of Wheeled Mobile Robots.

This paper presents a rapidly exploring random tree (RRT) algorithm with an effective post waypoint shift, which is suitable for the path planning of a wheeled mobile robot under kinematic constraints. In the growth of the exploring tree, the nearest node that satisfies the kinematic constraints is selected as the parent node. Once the distance between the new node and the target is within a certain threshold, the tree growth stops and a target connection based on minimum turning radius arc is proposed to generate an initial complete random path. The most significant difference from traditional RRT-based methods is that the proposed method optimizes the path based on Dubins curves through a post waypoint shift after a random path is generated, rather than through parent node selection and rewiring during the exploring tree growth. Then, it is proved that the method can obtain an optimal path in terms of the shortest length. The optimized path has good convergence and almost does not depend on the state of the initial random path. The comparative test results show that the proposed method has significant advantages over traditional RRT-based methods in terms of the sampling point number, the tree node number, and the path node number. Subsequently, an efficient method is further proposed to avoid unknown obstacles, which utilizes the original path information and thus effectively improves the new path planning efficiency. Simulations and real-world tests are carried out to demonstrate the effectiveness of this method.

The lncRNA AFAP1-AS1 is upregulated in metastatic triple-negative breast tumors and controls hypoxia-activated vasculogenic mimicry and angiogenesis

BackgroundVasculogenic mimicry (VM) is an alternative intratumoral microcirculation system that depends on the capacity of tumor cells to reorganize and grow in three-dimensional (3D) channel architectures like the capillaries formed by endothelial cells. Both VM and angiogenesis may coordinately function to feed cancer cells, allowing tumor growth. Long noncoding RNAs (lncRNAs) regulate critical cellular functions in cancer cells, including cell proliferation, apoptosis, angiogenesis, invasion, and metastasis. The lncRNA, known as actin filament-associated protein 1-antisense RNA 1 (AFAP1-AS1), has been described as an oncogene in diverse types of cancers. However, its role in VM and metastasis in triple-negative breast cancer (TNBC) is unknown.MethodsReverse transcription and quantitative polymerase chain reaction (RT‒qPCR) experiments were performed to evaluate the expression of 10 selected lncRNAs from literature in metastatic and nonmetastatic biopsies from TNBC patients. The expression of AFAP1-AS1 was analyzed in Genotype-Tissue Expression Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) datasets. The AFAP1-AS1 expression was knocked in TNBC Hs578T cells by transfection of specific siRNAs. Channel-like formation assays were performed using 3D cultures over Matrigel in hypoxia-treated Hs578T cancer cells with diminished expression of AFAP1-AS1. The angiogenesis tests were conducted using human umbilical vein endothelial cells (HUVECs) and AFAP1-AS1- silenced Hs578T cells on 3D cell cultures. The presence of VM (CD31-/PAS+) in tumor tissues from TNBC patients with and without metastasis was assessed through immunohistochemistry using endothelial marker CD31 antibodies and periodic acid-Schiff (PAS) staining.ResultsCompared with normal mammary tissues, AFAP1-AS1 expression was higher in breast cancer tissues. Moreover, AFAP1-AS1 expression was upregulated in the TNBC subtype compared to receptor-positive breast tumors. In addition, the expression of AFAP1-AS1 was correlated with the expression of the thirteen genes characteristic of a previously reported hypoxia signature. Interestingly, AFAP1-AS1 was upregulated in primary TNBC tumors from patients who developed metastasis compared with the nonmetastatic group. Functional analysis revealed that the knockdown of AFAP1-AS1 in Hs578T cells significantly impaired the hypoxia-induced VM, accompanied by a decrease in the development of 3D channel networks. Similarly, AFAP1-AS1 knockdown counteracts the angiogenic potential of cancer cells, as indicated by a reduction in the number of polygons, sprouting cells, and nodes in HUVEC cells. Remarkably, an increase in CD31-/PAS + staining of 3D channel networks in primary breast tumors from metastatic patients was found compared with the nonmetastatic group. Finally, we found that the number of blood vessels increased in the nonmetastatic group more than in the metastatic cohort.ConclusionsOur data suggested that AFAP1-AS1 controls both VM and angiogenesis in Hs578T breast cancer cells and that increased metastasis is associated with VM in TNBC patients.

Chronic Lymphocytic Thyroiditis is a Protective Factor for Lymph Node Metastasis in Papillary Thyroid Carcinoma: A Propensity Score Matching Analysis.

Aims/Background The connection between lymph node (LN) metastases in papillary thyroid carcinoma (PTC) and chronic lymphocytic thyroiditis (CLT) has been examined in a number of prior investigations. However, there is ongoing debate over the effect of CLT on LN metastasis in PTC. In order to explain the relationship between CLT and LN metastasis more convincingly, we aimed to retrospectively review clinical data to investigate the correlation between CLT and LN metastasis in PTC using propensity score matching (PSM). Methods Data on PTC patients at Wenzhou Central Hospital were collected retrospectively between 1 January 2018, and 31 March 2022. The patients were split into two groups based on whether they had CLT or not. The clinicopathological characteristics of the two groups were compared using a PSM analysis. The relationship between CLT and LN metastases was analyzed using logistic regression analysis. Results Among the 773 PTC patients collected and examined, 213 showed simultaneous CLT. Prior to PSM, patients with CLT displayed a significantly lower incidence of LN metastasis (34.3% VS 44.8%, p = 0.008), a lower metastatic LN ratio (0 (0, 0.17) VS 0 (0, 0.38), p = 0.011), and a greater number of LNs dissected (7 (5, 11) VS 5 (3, 7), p < 0.001). These differences persisted after the PSM of 208 pairs. After PSM, patients with CLT displayed a significantly lower incidence of LN metastasis (35.0% VS 44.7%, p = 0.045), a lower metastatic LN ratio (0 (0, 0.17) VS 0 (0, 0.33), p = 0.038), and a higher number of dissected LNs (7 (5, 11) VS 5 (3, 7), p ≤ 0.001). Additionally, the multivariate logistic regression analysis indicated that CLT had a protective role against LN metastasis in both the matched group (odds ratio (OR), 0.62; 95% confidence interval (CI): 0.39-0.96; p = 0.032) and the unmatched group (OR, 0.63; 95% CI: 0.44-0.91; p = 0.014). Conclusion Our data indicate that CLT may protect against LN metastases in patients with PTC. Patients having PTC with coexisting CLT have fewer LN metastases, a greater number of LNs dissected, and a lower metastatic LN ratio.

Wire injury induced moderate aortic valve stenosis in mice is accompanied by a chronic systemic inflammatory reaction

Abstract Background Patients with aortic valve stenosis (AS) have elevated serum levels of inflammation markers, and blood cytokine levels correlate with ventricular recovery after transcatheter aortic valve replacement. While presence of inflammatory processes in stenotic aortic valves is acknowledged, no systematic characterization of the systemic immune reaction upon AS has been performed, yet. Purpose Hypothesis of this study was that AS induces a systemic inflammatory reaction linked with local processes in the heart. Methods AS was induced by wire injury (WI) or sham surgery was performed in 3-4 months old male C57Bl/6J mice. AS severity, left ventricular (LV) function and hypertrophy indices were assessed with echocardiography (echo). After four weeks, explanted organs were weighted, and flow cytometry identified total leukocyte numbers in blood, heart, and peripheral immune organs (spleen, liver, lymph nodes) and uptake of Cy5-labelled perfluorocarbon nanoemulsions by whole blood leukocytes. Costimulatory molecules (flow cytometry, RT-qPCR) and cytokines (RT-qPCR, Multiplex Immunoassay) were analysed in heart, peripheral immune organs and blood. Results R-values were positive for spleen weight correlation with AS severity, cardiac function and mass suggesting cardiac hypertrophy to preserve heart function. Myocardial myeloid and T cell r-values were positive or negative, respectively, for correlation with spleen and liver weight, hinting at T cell recruitment from peripheral stores. Immune cell numbers in peripheral lymph nodes and spleen showed negative r-values for correlation with heart hypertrophy indices; number of liver myeloid cells correlated negatively with LV wall thickness (monocytes=-0.8571, p=0.0238) suggesting immune cell recruitment to hypertrophic hearts. Cytokine mRNA levels trended mainly towards increase in heart and regional lymph nodes and reduction in spleen and liver after WI. Correlation with echo was more homogeneous after WI, with r-values mainly positive, except of T cell activation markers, for aortic valves, but negative for myocardium, hinting at mechanisms preserving heart function. Correlating unchanged cytokine protein levels in myocardium and plasma with echo, r-values were mostly positive for myocardium, and were more positive than in sham for plasma. Echo and costimulatory molecule correlation showed a more homogeneous pattern in WI, with mostly positive r-values in myocardium and periphery, while most r-values were negative in sham. Together with reduced PFC-uptake by lymphatic cells, this hints at systemic immune cell activation in AS. Conclusion The results suggest that number and activation state of leukocytes in peripheral organs are directly linked to cardiac processes in AS. Considering the pathological value of inflammation, it is crucial to in future studies find out if modulation of the systemic inflammatory reaction relieves severity of AS and prevents development of heart failure.

Genome-wide dissection of genes shaping inflorescence morphology in 242 Chinese south–north sorghum accessions

The inflorescences morphology (IM) of sorghum (Sorghum bicolor L. Moench) affects its resistance to pests, diseases, and grain yields. However, the specific genetic factors underlying in IM are not yet fully elucidated. Here we conducted a comprehensive genome-wide association analysis (GWAS) to identify the stable and adaptive Quantitative Trait Loci (QTL) for five IM traits (panicle length, the number of cob nodes, the number of primary branches, the largest length of the primary branch, and panicle type) in a sorghum panel, which adapted to different environments from the south to north in China. Totally, 2,015,850 high quality single nucleotide polymorphisms (SNPs) were obtained. Population structure analysis showed that two distinct genetic sub-populations were divided according to their geographic origin. Seventy-one QTLs distributed in 41 genetic regions on 9 chromosomes were identified. These regions harbored 21 high-confident candidate genes that were homologous to rice domestication genes, including 7 related to IM. Two domestication-related genes (Sobic.003G052700 and Sobic.006G247700) were located into two major QTL regions (QTL3.4721839 and QTL6.58709500) which were identified in multi-environments. Allelic variations in the two genes displayed a geographical pattern, indicating that different IM traits were selected by south and north sorghum breeders, such as south sorghums had long and loose panicles in order to adapt the hot and humid climate, while north sorghums had short and compact panicle to increase planting density and grain yield per unit area due to dry climate. This work provides new breeding strategies and resources for developing locally adapted sorghum varieties.

Short-term outcomes and quality of life of esophagogastrostomy versus the double-tract reconstruction after laparoscopic proximal gastrectomy

BackgroundThere is no optimal reconstruction technique after proximal gastrectomy. The esophagogastrostomy (EG) is a rather simple procedure technically, but the incidences of reflux esophagitis and anastomotic stricture are higher. While the double-tract reconstruction (DTR) can lessen postoperative reflux esophagitis, it is technically complex with a long operation time. The purpose of this study was to evaluate the quality of life (QoL) and short-term outcomes of the two reconstruction techniques.MethodsWe retrospectively collected consecutive patients with upper-third gastric adenocarcinoma and adenocarcinoma of the esophagogastric junction (AEG) at our center between 2019 June and 2023 May. Patients who underwent laparoscopic proximal gastrectomy (LPG) with EG or DTR were included in this study. A comparison was made between the clinical and pathological characteristics of patients and their surgical parameters, postoperative complications, and its 1-year QoL in two groups. The QoL of the two groups was assessed by Visick grading, the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 and EORTC QLQ-STO22 scales at 1 year after operation. The nutritional status of the two groups was evaluated by BMI, hemoglobin and serum albumin.ResultsAII the qualified patients were divided EG group (n = 63) and DTR group (n = 93). Compared to the DTR group, the blood loss volume of EG group was more (p = 0.001). There were no significant differences in operation duration, number of lymph nodes dissected, and postoperative length of stay between the two groups(p > 0.05). No statistical differences were observed in terms of the incidence of early complications and Clavien-Dindo classification as well(p > 0.05). After one year, the Visick grade of the DTR group was better than EG group (p = 0.040). The multivariable logistic regression analysis showed the only independent risk factor for reflux esophagitis was the reconstruction method. According to the EORTC QLQ-C30 questionnaire, patients in the DTR group had a better global health status(p = 0.001) and complained less about nausea and vomiting(p = 0.033), and appetite loss (p = 0.022). Patients in the DTR group complained less about reflux (p = 0.030) based on the EORTC QLQ-STO22 questionnaire. The multiple linear regression analysis revealed that the reconstruction method, reflux esophagitis and age had a linear relationship with the global health status score. Regarding nutritional status, BMI of the two groups both decreased 1 year after operation, and BMI decline value of the DTR group was lower than EG group (p = 0.001). There is no statistically significant difference between the two groups as for postoperative change in hemoglobin and serum albumin.ConclusionOur findings suggest that it is possible for skilled surgeons to achieve minimal blood loss volume without significantly increasing operation duration when performing DRT, which does not raise risk. In terms of anti-reflux, postoperative QoL and BMI maintenance, 1-year postoperative follow-up outcomes reveal the DTR is superior to EG, which deserve further research and promotion.

Amoeba Monte Carlo algorithms for random trees with controlled branching activity: Efficient trial move generation and universal dynamics.

The reptation Monte Carlo algorithm is a simple, physically motivated and efficient method for equilibrating semidilute solutions of linear polymers. Here, we propose two simple generalizations for the analog Amoeba algorithm for randomly branching chains, which allowus to efficiently deal with random trees with controlled branching activity. We analyze the rich relaxation dynamics of Amoeba algorithms and demonstrate the existence of an unexpected scaling regime for the tree relaxation. Our results suggest that the equilibration time for Amoeba algorithms scales in general like N^{2}〈n_{lin}〉^{Δ}, where N denotes the number of tree nodes, 〈n_{lin}〉 the mean number of linear segments the trees are composed of, and Δ≃0.4.

Artificial neural network model for predicting water inflow into a reservoir

RELEVANCE of this study lies in the use of an artificial neural network to predict the volume of water in the Coca reservoir (Coca hydroelectric power station in Ethiopia). As you know, hydropower, being renewable energy, is one of the technologies that produce electricity with the least impact on global climate change. During this time, Ethiopia received about 87% (4,674 MW) of electricity from hydropower. It is one of the countries affected by the problems of climatic phenomena, such as floods, droughts and hurricanes, which affect the potential of hydropower. THE PURPOSE. In order to maintain safe operation, good production efficiency, better water resources management, effective decision-making, accident prevention and early warning and restrictions on electricity production, water volume forecasting is necessary. Which, in turn, is a nonlinear problem, and a multilinear perceptron-type neural network (MLP) is suitable for this purpose. METHODS. In this study, different models with different selected number of nodes and layers were identified, since there is no specific rule for determining the architecture of an artificial neural network. Statistical analysis (mean square error (MSE) and R-squared (R2)) was used to verify the validity of the model by comparing the actual values of water inflow with the predicted values. results. The inflow prediction was carried out using the ANN method based on a multilayer perceptron (MLP). The performance of each model was evaluated using the mean square error (MSE) and efficiency coefficient (R2), which are among the most commonly used statistical methods in hydrological modeling. CONCLUSION. The results obtained show that the models successfully predicted flood runoff over the reservoir.

Network modulation at stable states.

Advances in microarray and sequencing technologies have made possible the interrogation of biological processes at increasing levels of complexity. The underlying biomolecular networks contain large numbers of nodes, yet interactions within the networks are not known precisely. In the absence of accurate models, one may inquire if it is possible to find relationships between the states of such networks under external changes, and in particular, if such relationships can be model-independent. In this paper we introduce a class of such relationships. The results are based on the observation that changes to the equilibrium state of a network due to an alteration in an external input are "small" compared to the change in the input, a phenomenon we refer to as network modulation. It relies on the stability of the state. One consequence of network modulation is that response surfaces containing expression profiles of different mutants of an organism are low-dimensional linear subspaces. As an example, the expression profile of a double-knockout mutant generally lies close to the plane defined by the expression profiles of the wild-type and those of the two single-knockout mutants. This assertion is validated using experimental data from the sleep-deprivation network of Drosophila and the oxygen-deprivation network of Escherichia coli. The linearity of response surfaces is crucial in the design of a feedback control algorithm to move the underlying network from an initial state to a prespecified target state.

Sensitivity and Predictive Value of the Frozen Section of Sentinel Lymph Node Biopsy in the Post-neoadjuvant Setting: Experience From a Tertiary Care Hospital in a Resource-Limited Country.

Background Axillary lymph node status is one of the most important prognostic factors in breast cancer treatment, which can be confirmed by sentinel lymph node biopsy (SLNB).Intraoperative frozen sectionis an alternative method for SLNB, which can reduce the risks associated with secondary surgery.The feasibility and accuracy of SLNB after post-neoadjuvant chemotherapy (NACT) are affected by many factors as lymphatic drainage from the breast could be impaired due to fibrosis, fat necrosis, and granulation tissue formation, thus hampering the detection of the sentinel lymph node and afterward interpretation by pathologists due to therapy-related changes.Despite the increasing use of SLNB in post-NACT settings, there is still limited information on the accuracy of SLNB in resource-limited countries. Objective Our study aims to detect the sensitivity and predictive value of frozen section SLNB in the post-NACT setting while comparing it with final permanent histopathological results and considering final permanent histopathological results as standard. Materials and methods A total of 286 patients meeting the inclusion criteria from 2021 to 2022 were included in the study. Hematoxylin and eosin (H&E)-stained microscopic glass slides of frozen SLNB after NACT, permanent paraffin-embedded sections, and immunohistochemical stains were retrieved and reviewed.For all the categorical variables, including histologic type and grade, frequencies and percentages were obtained. Measures of central tendency and variability for continuous data such as age, number of sentinel lymph nodes received, and size of the largest nodal deposit were calculated.The chi-square test was used for the comparison of qualitative variables. A p-value of less than or equal to 0.05 was considered statistically significant. Results The median age of presentation was 47 years (range = 39 to 55 years). The median number of sentinel lymph nodes received was three (range = 2-4). At the time of frozen section reporting, out of a total of 286 cases, 229 (80.1%) cases were labeled as negative, 55 (19.2%) cases as positive, and two (0.7%) cases were deferred for permanent section results. Out of 229 cases labeled as negative at the time of the frozen section, 220 (76.9%) cases were true negative confirmed on permanent sections. A total of 66 (33.1%) cases were true positive, including two deferred cases and nine false negative cases, in addition to 55 cases labeled as positive on the initial frozen section. The study showed sensitivity, specificity, and accuracy of frozen section analysis of SLNB at 83.00%, 100%, and 96.15%, respectively, with a false negative rate (FNR) rate of 16.7%. Conclusion Further follow-up studies to definitively determine the role of SLNB following post-NACT inpatients who did not undergo axillary lymph node dissection (ALND) are needed. Continuous monitoring of the rate of false positives and false negatives of frozen sections on SLNB is essential as feedback for pathologists.

Robotic right colectomy versus laparoscopic right colectomy in patients with right colon cancer: a comparative study

BackgroundThe study aimed to compare the clinical outcomes of robotic right colectomy (RRC) versus laparoscopic right colectomy (LRC) in patients diagnosed with right colon cancer, given the increasing adoption of robotic surgical techniques and their potential benefits in oncologic surgery.MethodsThis retrospective comparative study included patients who underwent right colectomy at Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, between January 2019 and May 2022. The primary outcomes measured were the number of lymph nodes harvested. Key secondary outcomes included the operation time, intraoperative blood loss, postoperative complications, hospitalization costs, overall survival (OS), and disease-free survival (DFS). Data were analyzed using multivariable Cox proportional hazards regression to adjust for potential confounders.ResultsA total of 225 patients (aged 65.23 ± 11.45, 108 males) with right colon cancer were included, with 100 (44.4%) patients underwent RRC. Patients who underwent RRC had significantly more lymph nodes harvested (27.69 ± 12.59 vs. 24.43 ± 9.42, P = 0.028), and incurred higher total hospitalization costs compared to those with LRC (9.68 ± 7.12 vs. 5.28 ± 1.23 ten-thousand-yuan, P < 0.001). The OS and DFS were comparable between RRC and LRC (both P > 0.05) within a median follow-up of 27 (range, 9–44) months. Multivariable cox proportional hazards regression showed that patients underwent RRC had significantly higher risk for all-cause death compared with those underwent LRC [hazards ratio (HR) = 2.303, 95% confidence intervals (CI): 1.625–3.265, P < 0.001].ConclusionPatients underwent RRC seemed to have significantly more numbers of lymph nodes harvested and higher risk for all-cause death and higher hospitalization costs compared with those underwent LRC. These findings suggest a need for careful consideration of the benefits and risks associated with robotic versus laparoscopic right colectomy in clinical practice.Trial registrationNot applicable.

A preliminary exploration of reduced port laparoscopic proximal gastrectomy with right-sided overlap and single-flap valvuloplasty (ROSF)

Objective: This study aimed to share preliminary experiences of single-incision plus two ports laparoscopic proximal gastrectomy with right-sided overlap and single-flap valvuloplasty (ROSF). Methods: Following the 6th edition of the Japanese Gastric Cancer Treatment Guidelines, proximal gastrectomy with lymphadenectomy was performed. Using a single-port approach, the esophagus was transected at least 2 cm above the tumor's upper margin with linear staplers. The stomach was then extracted through a periumbilical incision, and the proximal stomach was subsequently transected extracorporeally, while ensuring appropriate resection margins on both the greater and lesser curvatures. A single flap was created before returning the remnant stomach to the abdominal cavity and re-establishing pneumoperitoneum. The No.2 clip was used to grasp and elevate the esophageal stump. An incision was made at the right lower edge of the esophageal stump to guarantee that the esophageal lumen was open. The linear stapler was then inserted into the openings of the stomach and esophagus to perform a side overlap anastomosis with a length of 3 cm. Another barbed suture was used to close the common opening of the esophagus and the stomach, and the same barbed suture were used to suture the gastric wall to the lower edge of the muscle flap. The first barbed suture was then used to sequentially suture the proximal brim of the flap to the esophagus and the right brim of the flap to the right brim of the mucosal window. After completion of anastomosis, a drainage tube was inserted through the right upper port. This procedure was employed from November 2023 to March 2024 on five patients diagnosed with adenocarcinoma of the esophagogastric junction and upper stomach. The cohort consisted of three males and two females, with an age range of 62 to 75 years and a body mass index (BMI) of 13.7 to 24.2 kg/m². All cases were preoperatively staged as T1-2N0M0, confirmed by endoscopic biopsy and enhanced CT scans of the chest, abdomen, and pelvis. Results: All five patients successfully underwent the surgery. The median surgery time was 180-325 minutes, with the intraoperative blood loss of 30-50 ml. The number of lymph nodes harvested ranged from 18 to 27. The time to first flatus, and restore liquid diet and was 2.0-5.0 and 1.0-3.0 days, respectively. The postoperative length of stay was 9.0-11.0 days. The pain scores on the Numeric Rating Scale (NRS). On the first day, the pain scores were 3.0 in two cases, 2.0 in two cases, and 1.0 in one case. On the second day, the pain scores were 2.0 in two cases and 1.0 in three cases. On the third day, the pain scores were 1.0 in four cases and 2.0 in one case. No short-term postoperative complications were observed, and there were no perioperative deaths. Conclusion: Single-incision plus two ports laparoscopic proximal gastrectomy with ROSF is safe and feasible.

Real-Life Comparative Analysis of Robotic-Assisted Versus Laparoscopic Radical Prostatectomy in a Single Centre Experience.

Background: The advantage of a robotic-assisted (RARP) over a laparoscopic (LRP) approach in radical prostatectomy (RP) remains to be demonstrated. Aim: The aim of the study is to use a homogeneous population in real life and single primary surgeon surgery to analyze the oncological and functional results based on the type of surgical approach and pathological features. Methods: This is a prospective trial on non-metastatic prostate cancer (PCa) patients considered after a multidisciplinary decision to conduct a RP, using a RARP or LRP approach. A real-life setting was analyzed at our Urological Departments using homogeneous criteria for the management of PCa cases and a single surgeon experience on 444 cases (284 LRP and 160 RARP). Results: Mean operating time was significantly lower in RARP (153.21 ± 25.1 min) than in LRP (173.33 ± 44.3 min) (p < 0.001). In cases submitted to an extended lymph node dissection (eLND), the mean number of lymph nodes removed was 15.16 ± 7.83 and 19.83 ± 4.78, respectively, in LRP and RARP procedures (p < 0.001), but positive lymph nodes (pN1) were similarly found in 15.8% of LRP patients and 13.6% of RARP patients (p = 0.430). Surgical margins (SM) positivity was not significantly higher in the RARP group (20.0%) when compared to the LRP group (15.9%) (p = 0.145). During the postoperative follow-up, a biochemical recurrence (BCR) was detected in 14.4% and 7.5% of cases in the LRP and RARP group, respectively, (p = 0.014). Better results of PAD tests at 3-month intervals using the RARP approach (mean pad weight 75.57 ± 122 g and 14 ± 42 g, respectively, in LRP and RARP (p < 0.01)) were described. Conclusions: In the comparison between the RARP and LRP approach, a clear advantage of the robotic approach is a significant reduction in operating times, days of hospitalization, and postoperative catheterization compared to laparoscopic surgery. It is not possible to describe any certain oncological advantage both in terms of surgical margins and pathological lymph nodes removed. In RARP cases a reduction to the limit of significance is described in terms of biochemical recurrence. RARP produces a more rapid recovery of urinary continence at 3 months postoperatively without significant advantages in terms of erective potency recovery.

A finite difference informed random walker (FDiRW) solver for strongly inhomogeneous diffusion problems

In nature, many complex multi-physics coupling problems exhibit strong diffusivity inhomogeneity. For instance, in the context of radionuclide absorption by porous wasteform materials within a flowing waste stream, the difference of species’ diffusivity in solid and liquid phases spans by 3 ∼ 8 orders of magnitude. To solve the diffusion equations with strongly inhomogeneous diffusivity, traditional discretization-based methods, such as the Finite Difference Method (FDM), require infinitesimally small-time steps (<10-10) as high spatial resolutions are employed in most microstructure evolution processes, leading to prohibitively high computational costs. This work developed an integrated numerical approach (FDiRW: Finite Difference informed Random Walk) to tackle this challenge. The idea is that utilizing the Random Walk concept, the fast diffusion is modelled as a superposition of point source’s solution for a concentration distribution while FDM is used to obtain the point source’s solution at each node. A mesh-coarsening algorithm is developed to generate an exclusive coarse mesh for FDiRW approach to maximize its efficiency. The effectiveness of the coarse mesh-based FDiRW approach is validated by benchmarking Finite Difference solutions. Numerical results demonstrated that FDiRW achieves a remarkable 1000x computational efficiency improvement over FDM while preserving desired accuracy for a medium-sized model of 192×192×192 grids. As models scale up, a floating-point operations (PLOPs) analysis of the FDiRW algorithm reveals that its computational complexity grows quadratically in terms of the number of nodes employed in computation.

Particle Virtual Element Method (PVEM): an agglomeration technique for mesh optimization in explicit Lagrangian free-surface fluid modelling

Explicit solvers are commonly used for simulating fast dynamic and highly nonlinear engineering problems. However, these solvers are only conditionally stable, requiring very small time-step increments determined by the characteristic length of the smallest, and often most distorted, element in the mesh. In the Lagrangian description of fluid motion, the computational mesh quickly deteriorates. To circumvent this problem, the Particle Finite Element Method (PFEM) creates a new mesh (e.g., through a Delaunay tessellation, based on node positions) when the current one becomes overly distorted. A fast and efficient remeshing technique is therefore of pivotal importance for an effective PFEM implementation in explicit dynamics. Unfortunately, the 3D Delaunay tessellation does not guarantee well-shaped elements, often generating zero- or near-zero-volume elements (slivers), which drastically reduce the stable time-step size. Available mesh optimization techniques have limited applicability due to their high computational cost when runtime remeshing is required. An innovative possibility to overcome this problem is the use of the Virtual Element Method (VEM), a variant of the finite element method that can make use of polyhedral elements of arbitrary shapes and number of nodes. This paper presents the formulation of a 3D first-order Particle Virtual Element Method (PVEM) for weakly compressible flows. Starting from a tetrahedral mesh, poorly shaped elements, such as slivers, are agglomerated to form polyhedral Virtual Elements (VEs) with a controlled characteristic length. This approach ensures full control over the minimum time-step size in explicit dynamics simulations, maintaining stability throughout the entire analysis.