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The aim of this study was to compare the use of computed tomography (CT) with automatic rib unfolding and three-dimensional (3D) volume-rendered imaging in the detection and characterization of rib fractures and flail chest. A total of 130 patients with blunt chest trauma underwent whole-body CT, and five independent readers assessed the presence and characterization of rib fractures using traditional CT images, automatic rib unfolding, and 3D volume-rendered images in separate readout sessions at least 2 weeks apart. A gold standard was established by consensus among the readers based on the combined analysis of conventional and reformatted images. Automatic rib unfolding significantly reduced mean reading time by 47.5%–74.9% (P < 0.0001) while maintaining a comparable diagnostic performance for rib fractures (positive predictive value [PPV] of 82.1%–93.5%, negative predictive value [NPV] of 96.8%–98.2%, and 69.4%–94.2% and 96.9%–99.1% for conventional axial images and 70.4%–85.1% and 95.2%–96.6% for 3D images) and better interobserver agreement (kappa of 0.74–0.87). For flail chest, automatic rib unfolding showed a PPV of 85.7%–100%, NPV of 90.4%–99.0%, and 80.0%–100% and 89.7%–100% for conventional axial images and 76.9%–100% and 89.0%–92.1% for 3D images. Automatic rib unfolding demonstrated equivalent diagnostic performance to conventional images in detecting acute rib fractures and flail chest, with good interobserver agreement and time-saving benefits. [ABSTRACT FROM AUTHOR]

Background/purpose: Small bowel (SB) accounts for the majority of gastrointestinal tract but its tumors are rare and always overlooked. In this study, we aimed to evaluate the epidemiology of SB tumors.Methods: This multicenter retrospective study utilized endoscopy database from 2006/11 to 2016/07. Baseline demographic characteristics, clinical, radiologic and endoscopic findings were collected.Results: Totally 103 (34 benign, 69 malignant lesions) patients with SB tumors in 1070 enteroscopic examinations were enrolled. There were male preponderance (56.3% males, 43.7% females), both in benign (52.9%, 49.1%) and malignant (58.0%, 42.0%) lesions, except for subtype gastrointestinal stromal tumors (GISTs) (31.6%, 68.4%). The age (mean ± SD) at diagnosis in malignant SB tumors (62.2 ± 15.6) was older than those with benign tumors (50.7 ± 21.4) (p < 0.01). Bleeding (43.7%), abdominal pain (40.8%) and ileus (10.7%) were the most common clinical presentations. Hamartoma (32.4%) and adenoma (14.7%) were the most common benign histology. Four major malignant histological subtypes were lymphomas (29.0%), GISTs (27.5%), adenocarcinomas (26.1%) and metastatic cancers (14.5%). SB adenocarcinoma patients (>60-year-old, 77.8%) were older than lymphomas (60%) and GISTs (50%). Proximally location rates of lymphomas, GISTs, adenocarcinomas were 25.0% (5/20), 84.2% (16/19), and 88.9% (16/18), respectively.Conclusion: This endoscopy-based study revealed the most common histology of benign SB tumors were hamartoma and adenoma, and malignant ones were lymphomas, GISTs, adenocarcinomas and metastatic cancers. Most of them were male gender, except for GISTs, and with proximal location, except for lymphomas. Further large-scale investigation efforts are warranted to elucidate the epidemiology of SB tumors. [ABSTRACT FROM AUTHOR]

Abstract: The use of open-cell metal foam in numerous technologies is increasing rapidly. Heat transfer measurements inside rectangular blocks of commercially available aluminum foam subjected to constant heat flux at one side are presented. Cases for different pore velocities, porosities and pore densities of the foam are given. Each foam block is cooled by a confined stream of ambient air. The temperature profile decays in an exponential fashion as the distance from the heat base increases. A two-dimensional, simplified analytical model for the heat transfer in the foam is summarized and adapted from the literature. The model neglects conduction in the fluid and invokes the local thermal equilibrium assumption for the solid and fluid phases in the foam. The model underestimated the temperature close to the foam’s entrance, and predicted the temperatures inside the foam within the experimental uncertainty for most of the data points. [Copyright &y& Elsevier]

Graft rejection after intestinal transplantation remains challenging. We aimed to use endoscopy for rejection prediction. Patients ≥7 years old who underwent intestinal transplantation between November 2016 and September 2019 were prospectively enrolled. Magnifying endoscopy under narrow-band imaging was performed through ileostomy. Endoscopic findings were reported as five components (each graded from 0–2): "V" (villi appearance), "E" (erythema), "N" (capillary network), "C" (crypt widening), and "H" (heterogeneity). The correlation between histological severity and endoscopic score was analyzed. Ninety-nine endoscopic biopsies from three female and one male patient were analyzed. The mean ± SD age was of 41.25±13.77 (range 29–58) years. Three short bowel syndrome patients after multiple intestinal resections and one with chronic intestinal pseudo-obstruction were indicated for intestinal transplantation. Sensitivity, specificity, and accuracy of V, E, N, C, and H scores for predicting rejection were 97.4%, 45.9%, 65.7%; 94.7%, 70.5%, 79.8%; 97.4%, 52.5%, 69.7%; 94.7%, 54.1%, 69.7%; and 97.4%, 62.3%, 75.8%, respectively. Pearson's correlation coefficients between total and individual V, E, N, C, H scores and histological rejection were 0.79, 0.64, 0.70, 0.71, 0.73, and 0.66, respectively (P <.001). To predict mild and moderate/severe rejection, total scores more than 4 and 6 had the sensitivity/specificity of 87.50%/57.38% and 96.67%/85.25%, respectively (area under the ROC 0.791 and 0.987). Endoscopic VENCH scoring is promising for predicting rejection after IT. More studies are warranted to validate such results. (ClinicalTrials.gov number, NCT03616548.) • Rejection is one of the most important reasons for graft failure after intestinal transplantation (IT). • Histopathology remains the gold standard for the diagnosis of graft rejection but delay after endoscopy. • Early changes of graft mucosa in rejection after IT could be observed by magnifying endoscopy with narrow-band imaging system. • VENCH endoscopic scoring system is a promising tool for earlier diagnosis of graft rejection after IT than histopathology. [ABSTRACT FROM AUTHOR]

Objectives: Esophageal second primary tumors (SPTs) in head and neck cancer (HNC) patients is not uncommon. The impact of image-enhanced endoscopy (IEE) screening for esophageal SPT on the outcome of HNC patients has not been well clarified.Methods and Methods: Patients with malignancies of the head and neck region and esophagus were recruited from a hospital-based cancer registry between July 2000-December 2016. IEE screening included magnifying endoscopy with narrow-band imaging and chromoendoscopy with Lugol's solution. Biopsied specimens with revised Vienna classification categories 1 and 2 were defined as group I, and those with categories 3 to 5 were defined as group II. The Kaplan-Meier estimate and Cox regression model were used for survival analysis.Results: Totally 1577 HNC and 501 esophageal cancer patients were enrolled. The 5-year overall survival (OS) rates of stage I/II HNC, stage III/IV HNC and esophageal cancer patients were 58%, 29%, and 8%, respectively (p < 0.01). The 5-year OS rate of HNC patients with negative IEE results was higher than that of HNC patients without IEE screening, followed by IEE screening groups I, II and esophageal cancer patients (44% vs. 39% vs. 35% vs. 11% vs. 8%, respectively, p for trend <0.01). Among advanced HNC patients, those who received IEE screening had a trend of better prognosis than those without screening (5-year OS rate of 31% vs. 28%, p = 0.17).Conclusions: IEE screening for esophageal SPTs is helpful in risk stratification and prognosis prediction for HNC patients. Routine IEE screening is recommended in HNC patients. [ABSTRACT FROM AUTHOR]

Abstract: Acetylation of calix[4]arene 1,3-dialkyl ethers yielded the corresponding monoacetates. The 1H NMR spectral analysis indicated that the products’ alkoxy moieties were ‘rotation restricted’. Acylation of calix[4]arene monoalkyl ethers with acetyl chloride yielded monoacetates and/or 2,3-diacetates in different reaction conditions. A simple recrystallization process was able to isolate 2,3-diacetates in good yield. The 1H NMR spectra of the diacetylated products indicated that those compounds also possessed the ‘rotation restricted’ alkoxy moieties. In the presence of K2CO3 as reaction base, alkylation of 2,3-diacetates produced the acetyl-migrated 1,3-dialkyloxy derivatives. Basic hydrolysis of the acetyl-migrated compounds yielded the known 1,3-dialkoxycalix[4]arenes. In the presence of NaH as reaction base, 2,3-diacetates were alkylated with and without the acetyl-migration. For the highly reactive benzyl bromide and allyl bromide, the majority of alkylation proceeded without acetyl-migration. In the other alkyl halides, the products were the acetyl-migrated 1,3-dialkoxy derivatives along with less than one-fourth the amount of non-migrated 1,2-dialkoxy derivatives. [Copyright &y& Elsevier]