Short-term clinical outcomes and five-year survival analysis of laparoscopic-assisted transanal natural orifice specimen extraction versus conventional laparoscopic surgery for sigmoid and rectal cancer: a single-center retrospective study

BackgroundThe cosmetic benefits of natural orifice specimen extraction (NOSE) are easily noticeable, but its principles of aseptic and tumor-free procedure have caused controversy.MethodsWe conducted a retrospective analysis of the clinical data of patients who underwent laparoscopic-assisted transanal NOSE or conventional laparoscopic surgery (CLS) for sigmoid and rectal cancer at our hospital between January 2018 and December 2018. The study aimed to compare the general characteristics, perioperative indicators, postoperative complications, and five-year follow-up results between the two groups.ResultsA total of 121 eligible patients were enrolled, with 52 underwent laparoscopic-assisted transanal NOSE and 69 underwent CLS. There were no significant differences observed between the two groups in terms of gender, age, body mass index (BMI), TNM stage, etc. (P > 0.05). However, the NOSE group exhibited significantly shorter total incision length and longer operation time compared to the CLS group (P < 0.05). There were no statistically significant differences observed between the two groups in terms of positive rate of bacterial culture, incidence rates of intraabdominal infections or anastomotic leakage (P > 0.05). Furthermore, during follow-up period there was no statistically significant difference observed between these two groups concerning overall survival rate and disease-free survival outcomes (P > 0.05).ConclusionsThe management of surgical complications in CLS is exemplary, with NOSE presenting a sole advantage in terms of incision length albeit at the cost of prolonged operative time. Therefore, NOSE may be deemed appropriate for patients who place high emphasis on postoperative cosmetic outcomes

Beyond One-Size-Fits-All: A Working Memory Dependent Dual-Process Model of the Testing Effect

Existing literature illustrates that the benefits of testing in learning may not be universal. However, individual differences are largely neglected in theoretical explanations of the testing effect. The lack of individualized predictions concerning the testing effect presents a substantial challenge for educators. Here, we propose a novel working memory-dependent dual-process model to elucidate individual differences in the testing effect. This model posits that the testing effect comprises two interlinked processes: a retrieval-attempt process and a post-retrieval re-encoding process. Both processes consume working memory (WM) resources. Thus, the effectiveness of testing as a learning tool is contingent upon an individual's available WM resources and the WM demands of the task. We substantiate our model with behavioral and neuroimaging evidence. This model invites further research to analyze the potential trade-off between testing benefits and WM demands, facilitating the development of personalized educational practices

Retrieval practice is costly and is beneficial only when working memory capacity is abundant

Abstract Numerous studies have shown that learned information practiced by testing is better retained than that practiced by restudying (the testing effect). However, results are inconsistent regarding the effect of working memory (WM) capacity on the testing effect. Here, we hypothesize that the effect of WM only emerges when task demands challenge WM capacity. We manipulated WM demands by pretraining 30 undergraduate participants in a multi-session visual search task before an associative learning task involving a test/restudy manipulation. The results revealed that, while participants with higher WM capacity showed a consistent testing effect, the benefit of testing only emerged in participants with lower WM capacity when learning familiar stimuli (low WM demands). We simulated the results using a modified source of activation confusion (SAC) model, which implemented a dual-process account of the testing effect. The results suggested that the testing effect only emerges when WM capacity is adequate for both processes

Sensing cell metabolism by time-resolved autofluorescence

We built a time-resolved confocal fluorescence spectroscopy system equipped with the multichannel time-correlated single-photon-counting technique. The instrument provides a unique approach to study the fluorescence sensing of cell metabolism via analysis of the wavelength- and time-resolved intracellular autofluorescence. The experiments on monolayered cell cultures show that with UV excitation at 365 nm the time-resolved autofluorescence decays, dominated by free-bound reduced nicotinamide adenine dinucleotide signals, are sensitive indicators for cell metabolism. However, the sensitivity decreases with the increase of excitation wavelength possibly due to the interference from free-bound flavin adenine dinucleotide fluorescence. The results demonstrate that time-resolved autofluorescence can be potentially used as an important contrast mechanism to detect epithelial precancer. (c) 2006 Optical Society of America

Retrieval Practice Is Costly: It Is Beneficial Only When Working Memory Capacity Is Abundant

Numerous studies have shown that learned information practiced by testing is better retained than that practiced by restudying (the testing effect). However, results are inconsistent regarding the effect of working memory (WM) capacity on the testing effect. Here, we hypothesized that the effect of WM only emerges when task demands challenge WM capacity. We manipulated WM demands by pretraining 30 undergraduate participants in a multisession visual search task before an associative learning task involving a test/restudy manipulation. The results showed that, while participants with higher WM capacity showed a consistent testing effect, the benefit of testing only emerged in participants with lower WM capacity when learning familiar stimuli (low WM demands). We simulated the results using a modified source of activation confusion (SAC) model, which implemented a dual-process account of the testing effect. The results suggested that the testing effect only emerges when WM capacity is adequate for both processes

Development of Tool Wear Standards and Wear Mechanism for Micro Milling Ti-6Al-4V Alloy

With the rapid development of high-precision-device technology, new demands are put forward for micro milling. The size effect and low cutting energy of micro milling make the process expensive and difficult, especially for Ti-6Al-4V alloys. The wear of the micro-milling cutter lacks corresponding international standards and its cutting mechanism is complex. In this paper, four kinds of micro-milling cutters with different wear states were obtained by designing micro-milling experiments, and the wear process and wear mechanism were observed and analyzed. The cutter diameter reduction, end face wear, flank wear and edge radius are comprehensively analyzed. It is considered that the formulation of a micro-milling-cutter wear standard needs comprehensive consideration, and the wear of end face 30 μm, wear of flank 35 μm and tool diameter reduction 55 μm can be used as the failure criteria of the micro-milling cutter. The wear forms mainly include abrasion marks, material adhesion, built-up edges and micro-collapse blades. Adhesive wear exists in the whole cutting process and plays a major role. Abrasive wear, diffusion wear and oxidation wear will occur when the cutting temperature reaches the melting point of Co. The wear of the micro-milling cutter is analyzed more comprehensively, a new wear-failure standard is formulated and the complex wear mechanism is revealed