The Effect of Inner Grooved Tubes on the Heat Transfer Performace of Air-Cooled Heat Exchangers of Co2 Heat Pump System

In the CO2 heat pump system, Poly alkyl glycol (PAG) oil is commonly used for lubrication of the compressor, while it is reported that the PAG oil has influence on the heat transfer performance due to its immiscibility against CO2 within its working condition. Experimental work has been carried out to investigate the heat transfer performance of fin and tube heat exchangers using CO2 as a refrigerant with taking PAG oil into account. From previous study it was found that the heat transfer performance decreased significantly in both evaporator and gascooler conditions when oil was mixed. The present work presents experimental results on three types of air-cooled heat exchangers with smooth and inner grooved tubes. It was found that the deterioration ratio of heat transfer performance with oil was different depending on the inner surface geometry of the grooved tubes. To understand this, flow visualization inside these tubes has also been carried out through transparent section made of glass, which can withstand high pressure. It was confirmed that the oil behavior inside tubes was related to heat transfer performance. Heat transfer performance can be improved by using inner grooved tubes with the optimal pattern to remove oil away from inner surface. These tubes are effective to develop high performance heat exchangers for the CO2 heat pump system

Development of a refrigerant to refrigerant heat exchanger for high efficiency CO2 refrigerant cycle

The performance of CO2 cycle is worse than that of HFC refrigerants since the working pressure of CO2 cycle is higher than that of HFC refrigerants which suffers higher compression and expansion losses. To enhance the cycle performance similar extent to HFC refrigerants, refrigerant to refrigerant heat exchangers need to be applied as one of the many components equipped. Specifically, when such a heat exchanger is used as an economizer, which works between high temperature refrigerant after the gas cooler and low temperature refrigerant by reducing to the intermediate pressure, it is confirmed from the visualization that the refrigerant flow in low temperature side is observed as a vapor-liquid dispersed flow. In such a condition, the evaporating performance is low since the liquid flows in the vapor core. In this study, aiming at weight saving and compactness, a newly designed aluminum double-tube heat exchanger in which surrounding multi-ports form instead of outside annulus is used. Spiral fins are applied in the inside tube to aim for attaching liquid refrigerant flowing in vapor core to the inside tube wall. The local heat transfer coefficient is experimentally measured in a single tube and it is confirmed that this new type heat exchanger can enhance heat transfer performance

The Quiescent Cellular State is Arf/p53-Dependent and Associated with H2AX Downregulation and Genome Stability

Cancer is a disease associated with genomic instability and mutations. Excluding some tumors with specific chromosomal translocations, most cancers that develop at an advanced age are characterized by either chromosomal or microsatellite instability. However, it is still unclear how genomic instability and mutations are generated during the process of cellular transformation and how the development of genomic instability contributes to cellular transformation. Recent studies of cellular regulation and tetraploidy development have provided insights into the factors triggering cellular transformation and the regulatory mechanisms that protect chromosomes from genomic instability

Repeated talaporfin sodium photodynamic therapy for esophageal cancer: safety and efficacy

[Background] Talaporfin sodium photodynamic therapy (tPDT) is an effective salvage treatment for local failure after chemoradiotherapy for esophageal cancer. Repeated tPDT could also be indicated for local recurrence or residue after the first salvage tPDT. However, the safety and efficacy of repeated tPDT have not been elucidated. [Methods] We reviewed 52 patients with esophageal cancer who were treated with the first tPDT at Kyoto University Hospital between October 2015 and April 2020. [Results] Among 52 patients, repeated tPDT after the first tPDT was indicated for 13 patients (25%), of which six had residual tumor, four had local recurrence after complete response (CR) after the first tPDT at the primary site, and six had metachronous lesion. The total session of repeated tPDT was 25; 16 were for primary sites and nine were for metachronous sites. Among them, six patients (46.2%) achieved local (L)-CR and nine lesions (56.3%) achieved lesion L-CR. By session, 10 sessions (40%) achieved L-CR. There were no severe adverse events except for one patient; this patient showed grade 3 esophageal stenosis and perforation after the third tPDT on the same lesion that was previously treated with porfimer sodium photodynamic therapy four times. [Conclusion] Repeated tPDT could be an effective and safe treatment for local failure even after salvage tPDT for esophageal cancer

The scaffold protein JSAP1 regulates proliferation and differentiation of cerebellar granule cell precursors by modulating JNK signaling

金沢大学がん研究所がん分子細胞制御Cerebellar granule cell precursors (GCPs) proliferate in the outer part of the external granular layer (EGL). They begin their differentiation by exiting the cell cycle and migrating into the inner part of the EGL. Here we report that JSAP1, a scaffold protein for JNK signaling pathways, is expressed predominantly in the post-mitotic GCPs of the inner EGL. JSAP1 knockdown or treatment with a JNK inhibitor enhances the proliferation of cultured GCPs, but the overexpression of wild-type JSAP1 leads to increased proportions of p27Kip1- and NeuN-positive cells, even with saturating concentrations of Sonic hedgehog (Shh), a potent GCP mitogen. However, these differentiation-promoting effects on GCPs are attenuated significantly in cells overexpressing a mutant JSAP1 that lacks the JNK-binding domain. Together, these data suggest that JSAP1 antagonizes the mitogenic effect of Shh on GCPs and promotes their exit from the cell cycle and differentiation, by modulating JNK activity. © 2008 Elsevier Inc. All rights reserved

Efficacy and safety of endoscopic submucosal dissection for gastric tube cancer: A multicenter retrospective study

BACKGROUND Recent improvements in the prognosis of patients with esophageal cancer have led to the increased occurrence of gastric tube cancer (GTC) in the reconstructed gastric tube. However, there are few reports on the treatment results of endoscopic submucosal dissection (ESD) for GTC. AIM To evaluate the efficacy and safety of ESD for GTC after esophagectomy in a multicenter trial. METHODS We retrospectively investigated 48 GTC lesions in 38 consecutive patients with GTC in the reconstructed gastric tube after esophagectomy who had undergone ESD between January 2005 and December 2019 at 8 institutions participating in the Okayama Gut Study group. The clinical indications of ESD for early gastric cancer were similarly applied for GTC after esophagectomy. ESD specimens were evaluated in 2-mm slices according to the Japanese Classification of Gastric Carcinoma with curability assessments divided into curative and non-curative resection based on the Gastric Cancer Treatment Guidelines. Patient characteristics, treatment results, clinical course, and treatment outcomes were analyzed. RESULTS The median age of patients was 71.5 years (range, 57-84years), and there were 34 men and 4 women. The median observation period after ESD was 884 d (range, 8-4040 d). The median procedure time was 81 min (range, 29-334 min), the en bloc resection rate was 91.7% (44/48), and the curative resection rate was 79% (38/48). Complications during ESD were seen in 4% (2/48) of case, and those after ESD were seen in 10% (5/48) of case. The survival rate at 5 years was 59.5%. During the observation period after ESD, 10 patients died of other diseases. Although there were differences in the procedure time between institutions, a multivariate analysis showed that tumor size was the only factor associated with prolonged procedure time. CONCLUSION ESD for GTC after esophagectomy was shown to be safe and effective

Molecular analysis of a variant type of familial amyloidotic polyneuropathy showing cerebellar ataxia and pyramidal tract signs

金沢大学がん研究所がん分子細胞制御A Japanese family with atypical type I familial amyloidotic polyneuropathy (FAP) in Iiyama, Japan, was studied. Most of the family members have dysfunctions of the central nervous system, in addition to typical symptoms of type I FAP. The transthyretin (TTR, also called prealbumin) gene of the atypical FAP (FAP-IY) was analyzed with recombinant DNA techniques and a RIA method. FAP-IY was found to have the mutation responsible for the methionine-for-valine substitution at position 30 of TTR, as in the case of typical type I FAP. However, analysis of DNA polymorphisms in the TTR locus showed that FAP-IY has a genetic background differing from that of the typical type I FAP. These observations lead to the consideration that a genetic factor(s) involved in the dysfunction of the central nervous system may locate in a chromosome region in close proximity to the TTR gene

Efficient overall water splitting in acid with anisotropic metal nanosheets

超高効率な水の電気分解を実現するナノシート状合金触媒を開発 --再生可能エネルギーによる水素社会実現へ大きく貢献--. 京都大学プレスリリース. 2021-02-17.Water is the only available fossil-free source of hydrogen. Splitting water electrochemically is among the most used techniques, however, it accounts for only 4% of global hydrogen production. One of the reasons is the high cost and low performance of catalysts promoting the oxygen evolution reaction (OER). Here, we report a highly efficient catalyst in acid, that is, solid-solution Ru‒Ir nanosized-coral (RuIr-NC) consisting of 3 nm-thick sheets with only 6 at.% Ir. Among OER catalysts, RuIr-NC shows the highest intrinsic activity and stability. A home-made overall water splitting cell using RuIr-NC as both electrodes can reach 10 mA cm−2geo at 1.485 V for 120 h without noticeable degradation, which outperforms known cells. Operando spectroscopy and atomic-resolution electron microscopy indicate that the high-performance results from the ability of the preferentially exposed {0001} facets to resist the formation of dissolvable metal oxides and to transform ephemeral Ru into a long-lived catalyst

Mild Acute Graft-Versus-Host Disease Improves Outcomes After HLA-Haploidentical-Related Donor Transplantation Using Posttransplant Cyclophosphamide and Cord Blood Transplantation

Haploidentical-related donor transplantation using posttransplant cyclophosphamide (PTCy-haplo) and cord blood transplantation (CBT) are valid alternatives for patients with hematological malignancies when HLA-matched donor transplantation (MDT) is unavailable. However, the effects of graft-versus-host disease (GVHD) on outcomes after these transplants have not been fully elucidated. Therefore, we evaluated the effects of acute and chronic GVHD on transplant outcomes after PTCy-haplo transplants and compared them with CBT and MDT. We included a total of 914 adult patients with hematological malignancies in the Kyoto Stem Cell Transplantation Group registry who received PTCy-haplo (N = 120), CBT (N = 402), and MDT (N = 392), and achieved neutrophil engraftment. A multivariate analysis revealed that grade I-II acute GVHD improved of overall survival (OS) after PTCy-haplo [hazard ratio (HR) = 0.39, P = 0.018] and CBT (HR = 0.48, P < 0.001), but not after MDT (HR = 0.80, P = 0.267) compared with patients without acute GVHD. Grade I-II acute GVHD had a trend toward reducing the risk of nonrelapse mortality (NRM) after PTCy-haplo (HR = 0.13, P = 0.060) and this positive effect was significant after CBT (HR = 0.39, P = 0.003). A negative impact of grade III-IV acute GVHD on NRM was observed after CBT and MDT, but not after PTCy-haplo. Limited chronic GVHD had a positive impact on OS after CBT and MDT, but not after PTCy-haplo. In conclusion, mild acute GVHD improved outcomes after PTCy-haplo and CBT, and limited chronic GVHD improved outcomes after CBT and MDT. These data indicated that the effects of GVHD on transplant outcomes depended on transplant platforms