•Weak disposability SBM-DEA model used to examine economic and environmental efficiency of 27 airlines.•Asia-based airlines are generally more efficient.•Fuel consumption is a major cause of ...inefficient airlines.
This study examined the economic and environmental efficiency of 27 global airlines in 2010. An extended environmental slacks-based measure data envelopment analysis model with the weak disposability assumption was developed to assess the efficiency of the airlines. Asia-based airlines are generally more efficient, followed by European and American airlines. The poor fuel consumption is a major cause of inefficient airlines both in economic and environmental aspects.
The winding eddy current loss can cause a dangerous temperature rise in an electric machine, especially in a coreless topology. The coreless axial-flux machine (AFM) is an unconventional machine ...configuration with many advantages, but its application is limited due to the winding eddy current loss. However, this problem has not yet been studied extensively in previous literature due to the relatively new topology. Furthermore, it is very difficult to analyze this loss accurately because it would usually require modeling each of the machine's conductors, extending the designing and computation time significantly. This article is one of the few that utilize a hybrid method to calculate winding ac loss with both analytical method and simplified 3-D finite element analysis (FEA) of a coreless AFM, under both no load and load conditions. This method can reduce the computation time while giving relatively good accuracy, making the coreless axial-flux topology becomes more feasible. Losses at multiple sizes of conductors were calculated using this method and thermal analysis was performed with 3-D FEA to determine which conductor size will not cause the thermal problem. The analysis results of losses and temperature are then validated with test results.
OBJECTIVENon-variceal upper gastrointestinal bleeding (NVUGIB) in patients receiving oral anticoagulants (OACs) may be fatal; however, little is known about re-bleeding and all-cause mortality after ...successful hemostasis. We investigated the clinical characteristics and risk factors for re-bleeding and death after successful hemostasis. METHODSPatients receiving OACs and diagnosed with NVUGIB between 2007 and 2021 were enrolled. All NVUGIB incidents were confirmed if definite bleeding in the upper gastrointestinal tract was detected via esophagogastroduodenoscopy. RESULTSA total of 132 patients receiving OACs were diagnosed with NVUGIB. Males were the majority (72, 54.5%), and bleeding was detected mostly in the stomach (99, 75%) and was most often due to peptic ulcers (PU) (88, 66.7%). After successful hemostasis of index NVUGIB, 40 patients (30.3%) experienced re-bleeding. Among them, 15 (37.5%) died, and among those, 3 (2.3%) were related to re-bleeding. Multivariate analysis revealed that duodenal bleeding (odds ratio OR: 3.305; 95% confidence interval CI: 1.152-9.479, p = 0.026) and Charlson comorbidity index score (CCI) (OR: 1.22; 95% CI: 1.052-1.419, p = 0.009) were significant risk factors for re-bleeding. Index albumin levels (OR: 0.134; 95% CI: 0.035-0.506, p = 0.003), previous PU or upper gastrointestinal bleeding (UGIB) history (OR: 4.626; 95% CI: 1.375-15.567, p = 0.013), and CCI (OR: 1.293; 95% CI: 1.058-1.581, p = 0.012) were related all-cause mortality. CONCLUSIONCCI and duodenal bleeding are risk factors for re-bleeding in patients with NVUGIB who were receiving OACs, while low index albumin levels and previous PU and UGIB history are associated with all-cause mortality.
This paper presents guidelines for determining the initial shape and specifications of a high-speed axial-flux permanent-magnet (AFPM) machine in a hybrid-electric propulsion system in two steps ...based on previous studies and product review results related to high-speed AFPMs. In the first step, three characteristics to be considered when designing AFPMs were classified as: electromagnetic, thermal, and mechanical. Then, the factors that should be considered in the design process to satisfy each characteristic were organized. In the second step, “the speed–output power” relationship was defined to predict the limits of applying AFPMs to high-speed applications, allowing an estimation of the limits of the speed range that can be used within the proposed output power.
Background and Aims Endoscopic resection has been performed for treatment of GI stromal tumors (GISTs) in the upper GI tract. However, the therapeutic roles of the endoscopic procedure remain ...debatable. We aimed in this retrospective study to evaluate the feasibility and long-term follow-up results of endoscopic resection of GISTs in the upper GI tract, compared with surgery. Methods Between March 2005 and August 2014, 130 cases of GIST in the upper GI tract were resected. We compared baseline characteristics and clinical outcomes including R0 resection rate and recurrence rate between the endoscopy group (n = 90) and surgery group (n = 40). Results The most common location of GIST was the stomach body in the endoscopy group, whereas it was the duodenum in the surgery group ( P = .001). Tumor size was significantly smaller (2.3 vs 5.1 cm; P < .001), and procedure time (51.8 ± 36.2 vs 124.6 ± 74.7 minutes; P < .001) and hospital stay (3.3 ± 2.4 vs 8.3 ± 5.4 days; P < .001) were significantly shorter in the endoscopy group than in the surgery group. The R0 resection rate was 25.6% in the endoscopy group, whereas it was 85.0% in the surgery group ( P = .001), and 50.0% of resected tumors belonged to a very low–risk group in the endoscopy group, whereas 35.0% and 30.0% belonged to low-risk and high-risk in the surgery group ( P = .001). However, during 45.5 months of follow-up, the recurrence rate was not significantly different between the 2 groups (2.2% vs 5.0%; P = .586). Conclusions Endoscopic resection might be an alternative therapeutic modality for GISTs in the upper GI tract in selective cases.
Pancreatic alpha amylase (P-AMY) is used as a biomarker of acute pancreatitis (AP) in human medicine. To our knowledge, there are no studies evaluating the usefulness of P-AMY in dogs with AP. In ...this study, we evaluated the diagnostic value of P-AMY, currently not verified in veterinary medicine. The AP group (
= 40) consisted of dogs with AP diagnosed using clinical signs and laboratory examinations, including abnormal canine pancreatic lipase (cPL) concentration, and compatible abdominal ultrasound examination at first presentation. Evaluation of the canine AP severity (CAPS) score was performed. The control group (
= 38) was composed of normal dogs without any abnormalities in clinical findings, blood exams or diagnostic imaging. The correlation of P-AMY with cPL was confirmed by Pearson's correlation analysis (
= 0.564,
< .001). The sensitivity and specificity for the most appropriate cut-off values of P-AMY were recorded similar to the values of DGGR. The dogs with AP and CAPS ≥11 had significantly higher serum P-AMY (
= .016) contrary to DGGR lipase and cPL. Furthermore, there was a significant difference in the median P-AMY dependent on the presence of systemic inflammatory response syndrome (
= .001). P-AMY showed similar level of diagnostic accuracy along with sensitivity and specificity compared to DGGR lipase. In addition, P-AMY showed a significant association with CAPS score, contrary to cPL and DGGR lipase. Along with other biomarkers associated with AP, P-AMY has the potential of usefulness as a supportive diagnostic and prognostic biomarker of AP in dogs.
This article describes the design of a very compact high-voltage pulsed power modulator for application in a medical linear accelerator. This modulator is manufactured with a modular cell structure ...based on a semiconductor switch, and the heat dissipation structure is minimized through a simple and efficient charge-and-discharge circuit design. In addition, an equalized charging strategy for multiple capacitors and a high-voltage electric field noise reduction strategy was applied. Thus, a high voltage pulsed-power modulator with a very compact size (310 (W) mm × 480 (H) mm × 230 (D) mm) and a high peak power density of 111 kW/L was realized without the use of an external cooling device such as a chiller. The modulator was built and experiments were conducted on high-voltage noninductive resistive load outputs. The results show that the modulator had a stable pulse voltage under various conditions, such as an output voltage of up to −40 kV, an output current of up to 100 A, a variable pulse width of 2-10 μs, and an output repetition rate of up to 1 kHz. In addition, the high-voltage insulation reliability of the proposed modulator and its applicability to magnetron loads were verified.
Early detection of tumors can significantly improve the outcome of tumor treatment. One of the most frequently asked questions in cancer imaging is how many cells can be detected non-invasively in a ...live animal. Although many factors limit such detection, increasing the light emission from cells is one of the most effective ways of overcoming these limitations. Here, we describe development and utilization of a lentiviral vector containing enhanced firefly luciferase (luc2) gene. The resulting single cell clones of the mouse mammary gland tumor (4T1-luc2) showed stable light emission in the range of 10,000 photons/sec/cell. In some cases individual 4T1-luc2 cells inserted under the skin of a nu/nu mouse could be detected non-invasively using a cooled CCD camera in some cases. In addition, we showed that only few cells are needed to develop tumors in these mice and tumor progression can be monitored right after the cells are implanted. Significantly higher luciferase activity in these cells allowed us to detect micrometastases in both, syngeneic Balb/c and nu/nu mice.
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the stomach. We evaluated the clinical outcomes of endoscopic treatment for gastric GISTs.
This is a single center, ...retrospective study that enrolled 135 cases of gastric subepithelial tumors (SETs) resected by endoscopic procedures and confirmed as GISTs by histopathology from March 2005 to July 2019. The immediate and long-term clinical outcomes were analyzed retrospectively.
The mean patient age was 57.9 years, and the mean tumor size was 2.1 cm. Of the tumors, 43.0% were located in the body, followed by the fundus (26.7%) and cardia (17.0%). Most tumors (85.2%) were resected by endoscopic submucosal dissection, followed by endoscopic mucosal resection (6.7%), submucosal tunneling endoscopic resection (5.9%), and endoscopic full-thickness resection (2.2%). Macroperforation occurred in 4.4% and microperforation in 6.7% of the cases. The R0 resection rate was 15.6%. However, the rate of complete resection by the endoscopic view was 90.4%, of which 54.8% of cases were in the very-low-risk group, followed by the low-risk group (28.1%), intermediate-risk group (11.9%), and high-risk group (5.2%). During 36.5 months of follow-up, recurrence was found in four (3.4%) of the 118 patients who were monitored for more than 6 months (low-risk group, 1/37 2.7%; intermediate-risk group, 2/11 18.2%; high-risk group, 1/6 16.7%).
Endoscopic treatment of a GIST appears to be a feasible procedure in selected cases. However, additional surgery should be considered if the pathologic results correspond to intermediate- or high-risk groups.
Previous studies reported substantial differences between proximal and distal gastric cancer, however, most of the cases included in these studies were advanced gastric cancers (AGCs). The aim of ...this study was to investigate the unique characteristics of proximal early gastric cancer (EGC) by comparing with distal EGC. From March 2007 to March 2016, proximal and distal EGC patients who underwent endoscopic or surgical resection at our institution were matched 1:3 according to age and sex. We retrospectively analyzed the clinical and histopathological information. A total of 368 patients were enrolled including 92 (25%) in the proximal and 276 (75%) in the distal group. The proportion of patients who underwent surgery (56.5 vs. 20.3%, p<0.001), undifferentiated type (38.0 vs. 19.6%, p<0.001), tumor size (29.5 ±19.4 vs. 20.3 ±16.8 mm, p<0.001) and submucosal (SM) invasion (60.9 vs. 25.7%, p<0.001) were significantly higher in the proximal group than in the distal group. In multivariate analysis, the proximal location of EGC was a significant risk factor for SM invasion in the total population (odds ratio OR, 3.541; 95% confidence interval CI, 2.053-6.110; p<0.001), and in subgroup with EGC < 30mm (n = 279) (OR, 5.940; 95% CI, 2.974-11.862; p<0.001). In conclusion, careful therapeutic decision of proximal EGC is essential due to the different histopathological characteristics such as large tumor size and higher potential for SM invasion.
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