274 research outputs found

    X-Ray Digital Industrial Radiography (DIR) for Local Liquid Velocity (VLL) Measurement in Trickle Bed Reactors (TBRs): Validation of the Technique

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    Local liquid velocity measurements in Trickle Bed Reactors (TBRs) are one of the essential components in its hydrodynamic studies. These measurements are used to effectively determine a reactor\u27s operating condition. This study was conducted to validate a newly developed technique that combines Digital Industrial Radiography (DIR) with Particle Tracking Velocimetry (PTV) to measure the Local Liquid Velocity (VLL) inside TBRs. Three millimeter-sized Expanded Polystyrene (EPS) beads were used as packing material. Three validation procedures were designed to test the newly developed technique. All procedures and statistical approaches provided strong evidence that the technique can be used to measure the VLL within TBRs

    Phantom for Evaluating Accuracy of Image Registration Software

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    Provided is a phantom for evaluating the accuracy of image registration software based on a result of matching tomograms of a predetermined position of the phantom, taken using two or more imaging apparatuses. Accordingly, it is possible to more efficiently evaluate the accuracy of the image registration software by comparing the tomograms with one another using a three-dimensional analysis. In addition, it is possible to facilitate the comparison of the tomograms with one another by installing a plurality of indicating bars in the phantom so that their cross sections can appear on each of the tomograms

    Method to Fabricate Portable Electron Source based on Nitrogen Incorporated Ultrananocrystalline Diamond (N-UNCD)

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    A source cold cathode field emission array (FEA) source based on ultra-nanocrystalline diamond (UNCD) field emitters. This system was constructed as an alternative for detection of obscured objects and material. Depending on the geometry of the given situation a flat-panel source can be used in tomography, radiography, or tomosynthesis. Furthermore, the unit can be used as a portable electron or X-ray scanner or an integral part of an existing detection system. UNCD field emitters show great field emission output and can be deposited over large areas as the case with carbon nanotube ā€œforestā€ (CNT) cathodes. Furthermore, UNCDs have better mechanical and thermal properties as compared to CNT tips which further extend the lifetime of UNCD based FEA

    CRISPR RNAs trigger innate immune responses in human cells

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    Here, we report that CRISPR guide RNAs (gRNAs) with a 5'-triphosphate group (5'-ppp gRNAs) produced via in vitro transcription trigger RNA-sensing innate immune responses in human and murine cells, leading to cytotoxicity. 5'-ppp gRNAs in the cytosol are recognized by DDX58, which in turn activates type I interferon responses, causing up to similar to 80% cell death. We show that the triphosphate group can be removed by a phosphatase in vitro and that the resulting St-hydroxyl gRNAs in complex with Cas9 or Cpfl avoid innate immune responses and can achieve targeted mutagenesis at a frequency of 95% in primary human CD4(+) T cells. These results are in line with previous findings that chemically synthesized sgRNAs with a 5'-hydroxyl group are much more efficient than in vitro-transcribed (IVT) sgRNAs in human and other mammalian cells. The phosphatase treatment of IVT sgRNAs is a cost-effective method for making highly active sgRNAs, avoiding innate immune responses in human cells.

    In vivo genome editing with a small Cas9 orthologue derived from Campylobacter jejuni

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    Several CRISPR-Cas9 orthologues have been used for genome editing. Here, we present the smallest Cas9 orthologue characterized to date, derived from Campylobacter jejuni (CjCas9), for efficient genome editing in vivo. After determining protospacer-adjacent motif (PAM) sequences and optimizing single-guide RNA (sgRNA) length, we package the CjCas9 gene, its sgRNA sequence, and a marker gene in an all-in-one adeno-associated virus (AAV) vector and produce the resulting virus at a high titer. CjCas9 is highly specific, cleaving only a limited number of sites in the human or mouse genome. CjCas9, delivered via AAV, induces targeted mutations at high frequencies in mouse muscle cells or retinal pigment epithelium (RPE) cells. Furthermore, CjCas9 targeted to the Vegfa or Hif1a gene in RPE cells reduces the size of laser-induced choroidal neovascularization, suggesting that in vivo genome editing with CjCas9 is a new option for the treatment of age-related macular degeneration.

    Clinicopathological Aspects of 542 Cases of Pancreatic Cancer: a Special Emphasis on Small Pancreatic Cancer

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    Small pancreatic cancers (longest diameter ā‰¤2 cm) have been regarded as preliminary to early pancreatic cancer, which was thought to be highly curable. During our experience since 1989, we evaluated 542 cases of pancreatic cancer. Among them we found 74 cases of tumors ā‰¤2 cm in diameter, small pancreatic cancer (TS1 pancreatic cancer). Well-differentiated adenocarcinomas (18.9%) and absence of symptoms (8.1%) were more frequent in patients with TS1 than in those with larger pancreatic tumors. Only 16 of the 74 patients (21.6%) with small pancreatic cancers had T1 tumors. According to the International Union Against Cancer (UICC) staging, only 11 patients (14.9%) were stage IA: their 5-yr survival rate was 23.3% and their median survival was 30.0 months. Among these 11 patients, 3 had tumors <1 cm; their median survival time was 30.0 months and their 5-yr survival rate was 50.0%. These findings may indicate that 'small' pancreatic cancer is not equivalent to 'early' pancreatic cancer

    The Usefulness of Percutaneous Transhepatic Cholangioscopy for Identifying Malignancies in Distal Commom Bile Duct Strictures

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    The diagnostic accuracy of percutaneous transhepatic cholangioscopy (PTCS) was compared to that of three radiologic modalities in distal common bile duct (CBD) strictures for the evaluation of clinical application. Ninety-five patients who underwent PTCS for the evaluation of distal CBD strictures (35 malignant and 60 benign) whose masses were not obvious from radiologic imagings were included. Confirmative diagnosis could not be reached by endoscopic retrograde cholangiopancreatography (ERCP) or radiologic findings in all cases. Specific findings on the computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP) and direct cholangiography were analyzed among 68 (25 malignant and 43 benign) out of the 95 patients in order to determine the sensitivity and specificity of three radiologic studies for the diagnosis of malignant distal CBD strictures, and to compare those results with those by a combination of PTCS-guided biopsy and tumor vessel observation on cholangioscopy. The sensitivity/specificity of CT, MRCP and direct cholangiography including ERCP in diagnosing malignant distal CBD strictures were 42.9%/65.8%, 53.3%/58.3%, and 70.8%/47.6% respectively, while it was 96%/100% for the combination of PTCS-guided biopsy and tumor vessel. PTCS is a useful method for differential diagnosis of distal CBD strictures, particularly when it is difficult to distinguish benign from malignant strictures by radiologic studies and when peroral approach is not feasible

    Effects of the route of erythropoietin administration on hemoglobin variability and cardiovascular events in hemodialysis patients

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    Introduction Despite of the routine use of erythropoietin in hemodialysis patients to correct anemia, its administration routeā€™s effects on hemoglobin variability and cardiovascular events remain elusive. Herein, we determined different erythropoietin administration routesā€™ effects on hemoglobin variability in hemodialysis patients and the associated factors of hemoglobin variability and cardiovascular events. Methods This is a post hoc analysis of a prospective, controlled, randomized, unblinded study with 78 Korean hemodialysis patients receiving intravenous (n = 40) or subcutaneous (n = 38) erythropoietin therapy. We evaluated hemoglobin variability by calculating the frequency of hemoglobin measurements outside the target range during all visits. The high-frequency group was defined by those with hemoglobin variability over the median value (25%) while the low-frequency group was defined by those with hemoglobin variability of <25%. Results In this analysis, 37 patients (51.1%) were male, and the mean age was 50.6 Ā± 12.5 years. The frequency of the value being outside the target hemoglobin range was higher in the subcutaneous group compared to the intravenous group (p = 0.03). The low-frequency group required significantly lower erythropoietin doses compared to the high-frequency group. In the adjusted Cox analysis, the parameter high group was a significant independent risk factor for cardiovascular events (p = 0.03). Conclusion The risk out of the target hemoglobin range increased with subcutaneous administration compared with intravenous erythropoietin administration in hemodialysis patients. An increased frequency of the value being outside the target hemoglobin range was also associated with an increased risk of cardiovascular events
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