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Abstract Background We externally validated the proposed 9th edition of the TNM staging classification with our institution’s prospectively collected data and compared it to the 8th edition for overall survival (OS) and freedom from recurrence (FFR). Methods A retrospective analysis was conducted of 4029 cases of stage I-III non-small cell lung cancer that underwent surgical treatment from January 2004 to December 2020. Survival was compared using Kaplan-Meier curves and multivariable Cox regression analysis. The concordance index (C-index), Alkaike information criterion (AIC), and R2 were used to assess the discriminatory ability. Results In the 9th edition, the N2 category (n = 352) was subdivided into N2a (n = 256, 72.7%) and N2b (n = 96, 27.3%). The TNM stage changes were as follows: (1) IIB to IIA, 151 cases (26.0%); (2) IIIA to IIB, 52 cases (11.5%); (3) IIIB to IIIA, 57 cases (61.3%); (4) IIIA to IIIB, 56 cases (12.4%). The survival curves of the proposed 9th edition demonstrated similar patterns to those of the 8th edition, but with a greater discriminative ability for OS and FFR. Subdividing N2 into N2a and N2b refined prognosis prediction. The C-index, AIC, and R2 demonstrated improved values in the proposed 9th edition compared to the 8th edition. Conclusions The proposed 9th edition of the TNM staging classification for lung cancer showed favorable prognostic validity and better discrimination ability than the 8th edition.

Background: This study aimed to evaluate the long-term impact of postoperative prolonged air leak (PAL) on pulmonary function. Methods: We enrolled 1,316 patients with pathologic stage I–III lung cancer who underwent lobectomy. The cohort was divided into 2 groups: those who experienced PAL (n=55) and those who did not (n=1,261). Propensity score matching was conducted at a 1:4 ratio, resulting in 49 patients in the PAL group and 189 in the non-PAL group. Changes in pulmonary function were compared among preoperative, 6-month postoperative, and 12-month postoperative measurements between the 2 groups. Results: The variables used for propensity score matching included age, sex, smoking history, body mass index, baseline pulmonary function, pathologic stage, and surgical approach. All standardized mean differences were less than 0.1. Six months postoperatively, the PAL group showed a greater reduction in both forced expiratory volume in 1 second (FEV1) (-13.0% vs. -10.0%, p=0.041) and forced vital capacity (FVC) (-15.0% vs. -9.0%, p

Owing to spatial effects and vortex flow, flow in research reactors that use plate-type fuels can be maldistributed to the parallel channels of the core, which significantly impacts the reactor safety. In this study, the core flow of an advanced research reactor was measured in a real-scale facility under various hydraulic conditions. For flow measurement, integrated pressure lines were embedded in the mockups of 22 fuel assemblies and six fission molybdenum assemblies. Each assembly mockup was individually calibrated to obtain the relationship between the pressure drop and flow rate. Real-scale facility, which implements the characteristics of the hydraulic conditions in research reactors, was then used to evaluate the assembly-to-assembly flow distribution under normal operating condition, a partially withdrawn condition for the follower fuel assemblies, no flow for the pool water management system, and 1:1.5 asymmetric inlet flow condition. As a parallel channel system, core flow distribution was analyzed with conventional header design approach. Taking into account the measuring uncertainty, the core flow was uniformly distributed within 5 % under all conditions. This was mainly because the core flow resistance was sufficiently high and the vortex flow was minimized by the perforated plate.

In an open-pool type research reactor with a downward forced flow in the core, pipes can be under sub-atmospheric pressure because of the large pressure drop at the reactor core in the atmospheric pool. Sub-atmospheric pressure can result in air inflow into the pipe from the pressure difference between the atmosphere and the inside of the pipe, which in a postulated pipe break scenario can lead to the breakdown of the cooling pump. In this study, a plant-scale experiment was conducted to study air inflow in large piping systems by considering the actual operational conditions of an advanced research reactor. The air inflow rate was measured, and the entrained air was visualized to investigate the behavior of air inflow and flow regime depending on the pipe break size. In addition, the developed drift-flux model for a large vertical pipe with a diameter of 600 mm was compared with other correlations. The flow regime transition in a large vertical pipe under downward flow was also studied using the newly developed drift-flux model. Consequently, the characteristics of two-phase flow in a large vertical pipe were found to differ from those in small vertical pipes where liquid recirculation was not dominant.

Background: Studies of the prognostic role of circulating tumor cells (CTCs) in early- stage non-small cell lung cancer (NSCLC) are still limited. This study investigated the prognostic power of CTCs from the pulmonary vein (PV), peripheral blood (PB), and bone marrow (BM) for postoperative recurrence in patients who underwent curative resection for NSCLC. Methods: Forty patients who underwent curative resection for NSCLC were enrolled. Before resection, 10-mL samples were obtained of PB from the radial artery, blood from the PV of the lobe containing the tumor, and BM aspirates from the rib. A microfabricated filter was used for CTC enrichment, and immunofluorescence staining was used to identify CTCs. Results: The pathologic stage was stage I in 8 patients (20%), II in 15 (38%), III in 14 (35%), and IV in 3 (8%). The median number of PB-, PV-, and BM-CTCs was 4, 4, and 5, respectively. A time-dependent receiver operating characteristic curve analysis showed that PB-CTCs had excellent predictive value for recurrence-free survival (RFS), with the highest area under the curve at each time point (first, second, and third quartiles of RFS). In a multivariate Cox proportional hazard regression model, PB-CTCs were an independent risk factor for recurrence (hazard ratio, 10.580; 95% confidence interval, 1.637–68.388; p

The adequate regulation of postoperative serum glucose level (SGL) is widely accepted; however, the effects for non-diabetic patients who underwent major pancreatic surgery have not yet been established. We discerned the relevance of the immediately postoperative SGL to short-term postoperative outcomes from major pancreatic surgery in non-diabetic patients. Between January 2007 and December 2016, 2259 non-diabetic patients underwent major pancreatic surgery at four tertiary medical centers in Republic of Korea. Based on a SGL of 200 mg/dL, patients were classified into two groups by averaging the results of four SGL tests taken on the first day after surgery, and their short-term postoperative outcomes were analyzed. A 1:1 propensity score matching method was conducted to establish the high SGL group (n = 568) and the normal SGL group (n = 568). The high SGL group experienced a significantly higher rate of level C complications in the Clavien-Dindo classification (CDc) than the normal SGL group (24.1% vs. 16.5%, p = 0.002). Additionally, an SGL of more than 200 mg/dL was associated with a significantly high risk of complications above level C CDc after adjusting for other risk factors (hazard ratio = 1.324, 95% confidence interval = 1.048–1.672, p = 0.019). The regulation of SGL of less than 200 mg/dL in non-diabetic patients early after major pancreatic surgery could be helpful for reducing postoperative complications.

Surgical resection is the only curative treatment for pancreatic ductal adenocarcinoma (PDAC). Currently, the TNM classification system is considered the standard for predicting prognosis after surgery. However, the prognostic accuracy of the system remains limited. This study aimed to develop new predictive nomograms for resected PDAC. The clinicopathological data of patients who underwent surgery for PDAC between 2006 and 2015 at five major institutions were retrospectively reviewed; 885 patients were included in the analysis. Cox regression analysis was performed to investigate prognostic factors for recurrence and survival, and statistically significant factors were used for creating nomograms. The nomogram for predicting recurrence-free survival included nine factors: sarcopenic obesity, elevated carbohydrate antigen 19–9, platelet-to-lymphocyte ratio, preoperatively-identified arterial abutment, estimated blood loss (EBL), tumor differentiation, size, lymph node ratio, and tumor necrosis. The nomogram for predicting overall survival included 10 variables: age, underlying liver disease, chronic kidney disease, preoperatively found portal vein invasion, portal vein resection, EBL, tumor differentiation, size, lymph node metastasis, and tumor necrosis. The time-dependent area under the receiver operating characteristic curve for both nomograms exceeded 0.70. Nomograms were developed for predicting survival after resection of PDAC, and the platforms showed fair predictive performance. These new comprehensive nomograms provide information on disease status and are useful for determining further treatment for PDAC patients.

Arterial hypotension during the early phase of anesthesia can lead to adverse outcomes such as a prolonged postoperative stay or even death. Predicting hypotension during anesthesia induction is complicated by its diverse causes. We investigated the feasibility of developing a machine-learning model to predict postinduction hypotension. Naïve Bayes, logistic regression, random forest, and artificial neural network models were trained to predict postinduction hypotension, occurring between tracheal intubation and incision, using data for the period from between the start of anesthesia induction and immediately before tracheal intubation obtained from an anesthesia monitor, a drug administration infusion pump, an anesthesia machine, and from patients' demographics, together with preexisting disease information from electronic health records. Among 222 patients, 126 developed postinduction hypotension. The random-forest model showed the best performance, with an area under the receiver operating characteristic curve of 0.842 (95% confidence interval [CI]: 0.736-0.948). This was higher than that for the Naïve Bayes (0.778; 95% CI: 0.65-0.898), logistic regression (0.756; 95% CI: 0.630-0.881), and artificial-neural-network (0.760; 95% CI: 0.640-0.880) models. The most important features affecting the accuracy of machine-learning prediction were a patient's lowest systolic blood pressure, lowest mean blood pressure, and mean systolic blood pressure before tracheal intubation. We found that machine-learning models using data obtained from various anesthesia machines between the start of anesthesia induction and immediately before tracheal intubation can predict hypotension occurring during the period between tracheal intubation and incision.

Background: We evaluated the early clinical outcomes of tricuspid valve annuloplasty (TAP) with the Tri-Ad annuloplasty ring for functional tricuspid regurgitation (TR). Methods: From January 2015 to March 2017, 36 patients underwent TAP with a Tri-Ad ring for functional TR. To evaluate the early clinical outcomes of TAP with the Tri-Ad ring, we conducted a propensity score-matched analysis comparing the Tri-Ad and MC³ tri-cuspid annuloplasty rings (n=34 in each group). The follow-up duration was 11.0±7.07 months. Results: There was 1 case of operative mortality (2.8%) and no cases of late mortality. Postoperative complications occurred in 15 patients (41%), including acute kidney injury in 6 patients (16%), bleeding requiring reoperation in 4 patients (11%), and low cardiac output syndrome in 4 patients (11%). There were no ring-related complications, such as atrioventricular block or ring dehiscence. The TR grade decreased significantly (from 2.03±1.06 to 1.18±0.92, p

Primary intrapulmonary thymoma (PIT) is a very rare lesion of uncertain pathogenesis. PIT should be considered when the histopathological appearance of a lung tumor shows features that are uncommon but similar to t hose of a t hymoma. In t his case r eport, w e discuss the case o f a 5 9-year-old female with a s olitary pulmonary nodule that was confirmed to be PIT on the basis of pathological tests. Treatment with complete resection showed good results.

Hypotensive events in the initial stage of anesthesia can cause serious complications in the patients after surgery, which could be fatal. In this study, we intended to predict hypotension after tracheal intubation using machine learning and deep learning techniques after intubation one minute in advance. Meta learning models, such as random forest, extreme gradient boosting (Xgboost), and deep learning models, especially the convolutional neural network (CNN) model and the deep neural network (DNN), were trained to predict hypotension occurring between tracheal intubation and incision, using data from four minutes to one minute before tracheal intubation. Vital records and electronic health records (EHR) for 282 of 319 patients who underwent laparoscopic cholecystectomy from October 2018 to July 2019 were collected. Among the 282 patients, 151 developed post-induction hypotension. Our experiments had two scenarios: using raw vital records and feature engineering on vital records. The experiments on raw data showed that CNN had the best accuracy of 72.63%, followed by random forest (70.32%) and Xgboost (64.6%). The experiments on feature engineering showed that random forest combined with feature selection had the best accuracy of 74.89%, while CNN had a lower accuracy of 68.95% than that of the experiment on raw data. Our study is an extension of previous studies to detect hypotension before intubation with a one-minute advance. To improve accuracy, we built a model using state-of-art algorithms. We found that CNN had a good performance, but that random forest had a better performance when combined with feature selection. In addition, we found that the examination period (data period) is also important.

Tachycardia is defined as a heart rate greater than 100 bpm for more than 1 min. Tachycardia often occurs after endotracheal intubation and can cause serious complication in patients with cardiovascular disease. The ability to predict post-intubation tachycardia would help clinicians by notifying a potential event to pre-treat. In this paper, we predict the potential post-intubation tachycardia. Given electronic medical record and vital signs collected before tracheal intubation, we predict whether post-intubation tachycardia will occur within 10 min. Of 1931 available patient datasets, 257 remained after filtering those with inappropriate data such as outliers and inappropriate annotations. Three feature sets were designed using feature selection algorithms, and two additional feature sets were defined by statistical inspection or manual examination. The five feature sets were compared with various machine learning models such as naïve Bayes classifiers, logistic regression, random forest, support vector machines, extreme gradient boosting, and artificial neural networks. Parameters of the models were optimized for each feature set. By 10-fold cross validation, we found that an logistic regression model with eight-dimensional hand-crafted features achieved an accuracy of 80.5%, recall of 85.1%, precision of 79.9%, an F1 score of 79.9%, and an area under the receiver operating characteristic curve of 0.85.

Massive efforts to develop neural interfaces have been made for controlling prosthetic limbs according to the will of the patient, with the ultimate goal being long-term implantation. One of the major struggles is that the electrode’s performance degrades over time due to scar formation. Herein, we have developed peripheral nerve electrodes with a cone-shaped flexible artificial conduit capable of protecting wire electrodes from scar formation. The wire electrodes, which are composed of biocompatible alloy materials, were embedded in the conduit where the inside was filled with collagen to allow the damaged nerves to regenerate into the conduit and interface with the wire electrodes. After implanting the wire electrodes into the sciatic nerve of a rat, we successfully recorded the peripheral neural signals while providing mechanical stimulation. Remarkably, we observed the external stimuli-induced nerve signals at 19 weeks after implantation. This is possibly due to axon regeneration inside our platform. To verify the tissue response of our electrodes to the sciatic nerve, we performed immunohistochemistry (IHC) and observed axon regeneration without scar tissue forming inside the conduit. Thus, our strategy has proven that our neural interface can play a significant role in the long-term monitoring of the peripheral nerve signal.

Background: Bile acid (BA) is a crucial determinant of the gut microbiome, and cholecystectomy can alter the physiology of BA. Physiological changes in BA resulting from cholecystectomy can also influence the gut microbiome. We aimed to identify the specific taxa associated with perioperative symptoms, including postcholecystectomy diarrhea (PCD), and to evaluate the effect of cholecystectomy on the microbiome by investigating the fecal microbiome of patients with gallstones. Methods: We analyzed the fecal samples of 39 patients with gallstones (GS group) and 26 healthy controls (HC group) to evaluate their gut microbiome. We also collected fecal samples from GS group 3 months postcholecystectomy. Symptoms of patients were evaluated before and after cholecystectomy. Further, 16S ribosomal RNA amplification and sequencing were performed to determine the metagenomic profile of fecal samples. Results: The microbiome composition of GS differed from that of HC; however, the alpha diversity was not different. No significant microbiome alterations were observed before and after cholecystectomy. Moreover, GS group showed a significantly lower Firmicutes to Bacteroidetes ratio before and after cholecystectomy than the HC group (6.2, P<0.05). The inter-microbiome relationship was lower in GS than in HC and tended to recover 3 months after surgery. Furthermore, ~28.1% (n= 9) of patients developed PCD after surgery. The most prominent species among PCD (+) patients was Phocaeicola vulgatus. Compared with the preoperative state, Sutterellaceae, Phocaeicola, and Bacteroidals were the most dominant taxa among PCD (+) patients. Conclusion: GS group showed a different microbiome from that of HC; however, their microbiomes were not different 3 months after cholecystectomy. Our data revealed taxa-associated PCD, highlighting the possibility of symptom relief by restoring the gut microbiome. [ABSTRACT FROM AUTHOR]

A highly compact biocompatible microprobe type fiber optic temperature sensor was experimentally demonstrated utilizing an inherently high thermo-optic coefficient of DNA biopolymer. The sensor was based on an all-fiber multimode interferometer (MMI) along a coreless silica fiber (CSF) spliced to an end of a single mode fiber. Au film was deposited the CSF end facet to provide a double path for MMI and it also worked as a probe terminal. The circumferential area of CSF was coated with DNA-cetyltrimethylammonium chloride (CTMA) thin solid film, which served as a temperature sensing head. We experimentally investigated thermo-optical properties of DNA-CTMA thin solid films to find its large negative thermo-optical coefficient -4.15 × 10-4/°C in the temperature range from 20 to 70 °C. DNA-CTMA coated fiber optic probe was immersed in a water bath to simulate the bio compatible environment whose temperature was varied in the range from 30 to 70 °C. The proposed sensor showed a hightemperature sensitivity of -0.22 nm/°C in the spectral shifts, and 0.085 dB/°C in the reflected optical power changes. The proposed probe can be readily applied in various types of in vivo point of care temperature monitoring. [ABSTRACT FROM AUTHOR]

Background: Computed tomography and serum tumor markers have limited value in detecting recurrence after curative surgery of pancreatic cancer. This study evaluated the clinical utility of 18Ffluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in diagnosing recurrence. Methods: One hundred ten patients underwent curative resection of pancreatic cancer were enrolled. The diagnostic value of abdominal computed tomography (CT), PET-CT and serum carbohydrate antigen (CA) 19-9 concentration were compared. The prognostic value of SUVmax on PET-CT was evaluated. Results: PET-CT showed relatively higher sensitivity (84.5% vs. 75.0%) and accuracy (84.5% vs. 74.5%) than CT, whereas PET-CT plus CT showed greater sensitivity (97.6%) and accuracy (90.0%) than either alone. In detecting distant recurrences, PET-CT showed higher sensitivity (83.1% vs. 67.7%) than CT. Nineteen patients showed recurrences only on PET-CT, with eleven having invisible or suspected benign lesions on CT, and eight had recurrences in areas not covered by CT. SUVmax over 3.3 was predictive of poor survival after recurrence. Conclusions: PET-CT in combination with CT improves the detection of recurrence. PET-CT was especially advantageous in detecting recurrences in areas not covered by CT. If active post-operative surveillance after curative resection of pancreatic cancer is deemed beneficial, then it should include PET-CT combined with CT. [ABSTRACT FROM AUTHOR]

Background/Aims: Extended cholecystectomy is generally recommended for patients with T2 gallbladder cancer. However, few studies have assessed the extent of resection relative to T2 gallbladder tumor location. This study analyzed the effects of surgical methods and tumor location on survival outcomes and tumor recurrence in patients with T2 gallbladder cancer. Methods: Clinicopathological characteristics, extent of resection, survival rates, and recurrence patterns were retrospectively analyzed in 88 patients with pathologically confirmed T2 gallbladder cancer. Results: The 5-year disease-free survival rate was 65.0%. Multivariate analysis showed that lymph node metastasis was the only independent risk factor for poor 5-year disease-free survival rate. Survival outcomes were not associated with tumor location. Survival tended to be better in patients who underwent extended cholecystectomy than in those who underwent simple cholecystectomy. Recurrence rate was not affected by surgical method or tumor location. Systemic recurrence was more frequent than local recurrence without distant recurrence. Gallbladder bed recurrence and liver recurrence were relatively rare, occurring only in patients with liver side tumors. Conclusions: Extended cholecystectomy is the most appropriate treatment for T2 gallbladder cancer. However, simple cholecystectomy with regional lymph node dissection may be appropriate for patients with serosal side tumors. [ABSTRACT FROM AUTHOR]