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Cholangitis has been reported as an immune-related adverse event, although it rarely occurs. Here we report a case of cholangitis due to atezolizumab in a 77-year-old woman who had been treated with atezolizumab and nab-paclitaxel for breast cancer and lung metastasis. On the seventh cycle, she presented with fever and epigastric pain, and computed tomography and endoscopic ultrasound showed slight wall thickening of the common bile duct, and transpapillary bile duct biopsy was performed. Pathologically, CD8

Background and Aim We aimed to identify clinical features that suggest that coronavirus disease 2019 (COVID‐19) should be a differential diagnosis in patients presenting with a chief complaint of fever and abnormal liver function. Methods We retrospectively studied the presence or absence of abnormal liver function in 216 patients diagnosed with mild–moderate severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection between February and September 2020. Results Abnormal liver function was observed in 51 patients with mild–moderate COVID‐19. The median peak aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels were 57.5, 75.5, and 332.5 U/L, respectively. The median number of days from symptom onset to peak AST, ALT, and LDH were 8.5, 9, and 8.5, respectively. The median peak LDH/AST ratio was 9.0. Low lymphocyte‐to‐white blood cell ratio and elevated LDH were found to be independent contributing factors for intensive care unit (ICU) admission on a multivariate analysis. Conclusions AST‐predominant AST/ALT/LDH elevation peaking 8–9 days after symptom onset and not accompanied by elevated alkaline phosphatase or gamma‐glutamyl transferase may be a useful clinical feature for differentiating COVID‐19 from other diseases. Since the median LDH/AST ratio was 9.0, it seems that the abnormal liver function caused by SARS‐CoV‐2 is an indirect damage to liver cells due to elevated cytokine levels caused by liver‐infiltrating lymphocytes. SARS‐CoV‐2 infection should be considered in patients presenting with a chief complaint of fever and liver injury; those with a high lymphocyte‐to‐white blood cell ratio or and a high LDH/AST ratio may be admitted to the ICU., Aspartate aminotransferase (AST)‐predominant AST/alanine aminotransferase/lactate dehydrogenase (LDH) elevation peaking 8–9 days after symptom onset and not accompanied by elevated alkaline phosphatase or gamma‐glutamyl transferase may be a useful clinical feature for differentiating coronavirus disease 2019 from other diseases. Since the median LDH/AST ratio was 9.0, it seems that the abnormal liver function caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is an indirect damage to liver cells due to elevated cytokine levels caused by liver‐infiltrating lymphocytes. SARS‐CoV‐2 infection should be considered in patients presenting with a chief complaint of fever and liver injury.

We present the case of an 86-year-old man who had undergone left nephrectomy for renal cell carcinoma (clear cell carcinoma) 22 years ago. He visited the emergency department complaining of right hypochondrial pain and fever. He was eventually diagnosed with acute cholangitis. Abdominal contrast-enhanced computed tomography showed multiple tumors in the pancreas. The tumor in the pancreatic head obstructed the distal bile duct. Endoscopic retrograde cholangiopancreatography detected bloody bile juice flowing from the papilla of Vater. Therefore, he was diagnosed with hemobilia. Cholangiography showed extrinsic compression of the distal bile duct; a 6 Fr endoscopic nasobiliary drainage tube was placed. Endoscopic ultrasound showed that the pancreas contained multiple well-defined hypoechoic masses. Endoscopic ultrasound-guided fine-needle aspiration was performed using a 22 G needle. Pathological examination revealed clear cell carcinoma, and the final diagnosis was pancreatic metastasis of renal cell carcinoma (RCC) causing hemobilia. A partially covered metallic stent was placed in the distal bile duct. Consequently, hemobilia and cholangitis were resolved.

Objective Both a percutaneous biopsy and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) have been widely performed for liver tumors. However, no studies have compared these two biopsy methods. Method A retrospective study was conducted using medical records for patients who underwent a liver tumor biopsy from 2012 to 2019. The cases were classified into two groups for a comparison: an ultrasound-guided percutaneous biopsy group (percutaneous group) and an EUS-FNA group (EUS group). Results A total of 106 patients (47 in the percutaneous group and 59 in the EUS group) were included. The final diagnosis was malignant in 100 cases and benign in the remaining 6 cases. While the median lesion diameter was 62 mm in the percutaneous group, it was significantly smaller (34 mm) in the EUS group (p

Endoscopic transpapillary gallbladder drainage (ETGBD) is widely performed. However, there is no consensus on the appropriate diameter, length, and shape of the stent that should be used in this procedure. In addition, there are limited data on the outcomes of permanent ETGBD. In our facility, a stent with a novel spiral structure (IYO-stent) is permanently placed in patients with acute cholecystitis who are not indicated for surgery. This study examined the efficacy and safety of the IYO-stent in cases of permanent ETGBD.We retrospectively examined patients who underwent permanent ETGBD using the IYO-stent from April 2018 to December 2020.Eleven patients were included in this study. The technical success and the clinical success rate were 91%. One patient had a post-procedure adverse event (post-endoscopic sphincterotomy bleeding). Within the median observation period of 312 days (range: 109-742), late adverse events, including cholangitis (Permanent ETGBD with IYO-stent is an effective treatment for the patients with acute cholecystitis who are not indicated for surgery.

Endoscopic transpapillary gallbladder drainage (ETGBD) is an established procedure and is listed in the Tokyo guidelines 2018. Although there are many reports of ETGBD in normal anatomy cases, it is rarely performed for patients with a surgically altered anatomy. We herein report the case of a patient who underwent ETGBD with Billroth-II reconstruction. ETGBD could be an effective treatment option even for patients with a surgically altered anatomy.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor in the digestive tract. Recurrences may occur even after radical resection; however, recurrence later than 10 years after surgery is rare. We report a case of GIST with recurrence of liver metastasis 25 years after surgery. A 56-year-old man complained of sudden epigastric pain and was transferred to the emergency department. He had undergone partial resection of the small intestine for leiomyosarcoma 25 years previously. Abdominal computed tomography showed multiple liver tumors with massive hemorrhage. Ultrasound-guided percutaneous biopsy was performed for the 15-mm hepatic tumor in segment 2. Pathological findings revealed proliferation of spindle-shaped atypical cells, and immunostaining for c-kit and CD34 was both positive; the patient was therefore diagnosed with GIST. He then underwent chemotherapy for 7 years but died of multiple organ failure due to GIST. Autopsy revealed GIST occupying the entire liver with peritoneal dissemination, and minute lung metastases that could not be identified by CT were also detected. This case is interesting in considering the recurrence of GIST, and we will report it together with the literature review.

Gate-oxide and inter-gate-oxide defects in floating-gate transistors and flash memories, the number of which has been minimized but is still not zero, have been examined extensively. Gate-oxide defects are due to 0.1 μ m size octahedral void pits at the Si surface. They are originally grown-in defects in the Si crystal and appear as surface pits when they are truncated at the surface when wafers are sliced and polished. On the other hand, inter-gate oxide defects are due to polygonal-shaped voids at the poly-silicon grain boundary. These defects are produced as a negative crystal in the crystallization process of amorphous Si during annealing. Methods for eliminating the above defects are suggested.

Copper decoration followed by transmission electron microscopy (TEM) observation is proposed for identifying defects in thermal oxides of polysilicon films. This method uses copper decoration to detect the location of defects in the oxide, and sample thinning for TEM observation. The advantage of copper decoration is that the electronic current needed for defect detection is very small, so it does not change the original oxide-defect structure. TEM and scanning electron microscope observations revealed that the defects are polygonal voids located on the polysilicon grain boundary. The diameter of a void was typically 70 nm. A stress-induced migration of silicon atoms along grain boundaries may be related to the formation of the voids. A model for defect formation is presented.

Octahedral cavities have recently been found in the Czochralski silicon (CZ‐Si) substrate surface layer just under oxide defects. We investigate the effect that adding HCl to oxygen during oxidation has on the oxide defect density. The effect of intentionally introducing impurities onto a Si surface on the oxide defect density is also examined. Our experimental results suggest that impurities are closely related to the generation of oxide defects. A model is presented in which impurities are incorporated into the growing octahedral cavities during Si crystal growth, and then introduced into the growing oxides during thermal oxidation. These impurities in the oxides then act as a conductive path (oxide defects) in the insulator on the CZ‐Si.

Recently, octahedron structures have been found in the Czochralski‐silicon substrate surface layer just under the oxide defects. An attempt is made to characterize these structures by analysis with transmission electron microscopy and energy‐dispersive x‐ray spectroscopy. Several results indicate that the structure is full of vacancies. This is contrary to previously reported results suggesting that the octahedron structures found in Si bulk are filled with amorphous SiO2. A model for the formation of an octahedron structure with many vacancies is proposed.

We have observed the origin of defects in SiO2 thermally grown on Czochralski silicon substrates. Samples were prepared by copper decoration to locate oxide defects, focused ion beam etching to mark them, and subsequent silicon‐substrate thinning for transmission electron microscope observation. Polyhedron structures with sizes ranging from 150 to 300 nm are found in the underlying silicon‐substrate surface layer just under the oxide defects. Two polyhedron structures superimposed on each other are also observed. It is believed that these structures are related to the presence of oxygen precipitates. Oxide defects are thought to arise due to oxide thinning induced at the edge of the silicon‐substrate surface adjacent to the octahedron structures.

Analysis by TEM-energy-dispersive-X-ray-spectroscopy indicates that the majority of the octahedral structure found just under the oxide defect with Czochralski Si is void. This is contrary to previously reported results suggesting that the octahedral structures found in Si bulk are filled with amorphous SiO2. We investigate three models to explain our results. The first model, which we think most probable, suggests that the void formation occurs during Si crystal growth. The second model indicates that octahedral structures full of SiO2 are formed during Si crystal growth and, after wafer slicing, much of the SiO2 is removed. The third model suggests that the void is formed during copper decoration. We show some experimental results that are inconsistent with the second and third models.

Radical polymerization of several alkyl allyl oxalates, including methyl allyl oxalate (MAO), ethyl allyl oxalate, propyl allyl oxalate, butyl allyl oxalate, and octyl allyl oxalate, was conducted in the evolution of carbon dioxide at elevated temperatures, and was compared with the anomalous polymerization behavior of diallyl oxalate (DAO) discussed in our earlier article11 . The kinetic equations for the polymerization of alkyl allyl oxalate were derived following the kinetic treatment of the DAO polymerization by further consideration of the absence of cyclization of the growing polymer radical and the effective reinitiation by alkyl radical, and were then satisfactorily applied to the polymerization of MAO, as a representative alkyl allyl oxalate. The evolution of carbon dioxide in the polymerization of alkyl allyl oxalates was enhanced with the increase of bulkiness of the alkyl substituent, as a result of steric suppression of the propagation of the growing polymer radical.

Le prepolymere, prepare, en masse, a 80°C, en presence de peroxyde, de benzoyle, est postpolymerise en solution dans le phtalate de diethyle, en presence de peroxyde de dicumyle, a haute temperature (entre 120 et 150°C)

First, the thermal behavior of diallyl oxalate prepolymer (PDAO) at 130–300°C was preliminarily compared with diallyl phthalate prepolymer; PDAO was self-curable and degraded easily accompanying the evolution of gas. Next, the thermal degradation of PDAO was investigated in detail by TG. The TG curve of PDAO compared with those of various diallyl dicarboxylate prepolymers was peculiar suggesting two stages of thermal degradation processes with two maximum degradation temperatures, although the first stage is relevant to the significant release of carbon dioxide. In addition, the effect of the structural units, involving uncyclized, cyclized, and crosslinked units, on the thermal degradation of PDAO was examined; the thermal degradation rate was reduced with an increase in the cyclized units and was independent of the content of crosslinked units. From these results, the thermal degradation mechanism of PDAO is briefly discussed in terms of a radical mechanism.

The occurrence of head-to-head (HH) addition in the radical polymerization of diallyl oxalate (DAO) was examined under various polymerization conditions. The content of HH linkage in poly (DAO) was reduced in comparison with allyl acetate and diallyl succinate; this may be ascribed to the high polarity of DAO inducing a polar effect on the intermolecular propagation of the growing polymer radical, resulting in reduced HH addition. The correlation between addition modes and evolution of carbon dioxide characteristic of DAO polymerization at elevated temperatures is mechanistically discussed in detail, with special focus on the solvent effect and the reduced dismutation of the cyclized radical compared to the uncyclized one.

In order to improve the quality of GaAs crystal, it is indispensable to conduct ultramicroanalysis of impurities in GaAs. For the analyses in this paper standard samples were made by adding a certain amount of impurities which can adequately be detected by chemical analyses. Using these samples, the SSMS, SIMS and chemical analysis methods are examined. The results are: (1) three chemical analysis methods (FLAA, ICP and colorimetric methods) are examined and permit a detection limit of 0.05 ∼ 5 ppm and a CV value of ±30%. (2) For the SSMS method, a process for making a specimen electrically conductive by applying a vacuum-evaporated silver film is introduced. Comparing this result with those obtained by the chemical methods, a relative sensitivity factor is found which permits determination of the absolute value and it is possible to conduct analysis with detection limits of 10 ∼ 30 ppb and CV value of ±30%. (3) For the SIMS method, the secondary ionization yields for B, Al, Si, S, Cr and Mn are obtained, by comparison with the results of chemical analysis, which makes absolute quantitative analyses of these elements possible. The accuracy of quantitative analysis in which ion-implanted specimens were used for the standard samples is confirmed.

As SIMS has a very high sensitivity, it is useful for analyzing low concentrations of impurities in GaAs [1]. Usually, ion-implanted samples are used as standards for SIMS quantitative analysis. However, secondary ion yields of various impurities in GaAs have not been investigated, because for GaAs, there are no standard samples having certified values such as with NBS standard samples.