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1.
Article in English | MEDLINE | ID: mdl-35748738

ABSTRACT

Takayasu arteritis results in a variety of vascular symptoms, and there are some cases in which progressive vascular lesions require surgical intervention. We present a case with ascending aortic aneurysm, right common carotid artery stenosis, left common carotid artery occlusion and left subclavian artery stenosis caused by Takayasu arteritis that was successfully treated with total arch replacement and ascending aorta to right internal carotid artery bypass.


Subject(s)
Aortic Aneurysm , Carotid Artery Diseases , Takayasu Arteritis , Carotid Artery, Common/diagnostic imaging , Carotid Artery, Common/surgery , Constriction, Pathologic , Humans , Takayasu Arteritis/complications , Takayasu Arteritis/diagnostic imaging , Takayasu Arteritis/surgery
2.
Asian Cardiovasc Thorac Ann ; 30(7): 772-778, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35234053

ABSTRACT

BACKGROUND: We studied surgical outcomes of acute type A aortic dissection and compared early and late outcomes between septuagenarians and octogenarians. METHODS: From 2010 to 2019, we evaluated 254 consecutive patients with acute type A aortic dissection. We performed emergent operations within 48 h of symptom onset for 188 patients, including 59 septuagenarians and 32 octogenarians. RESULTS: The overall 30-day mortality rate was 8.5% in septuagenarians and 9.4% in octogenarians (p = 1.0). The hospital mortality rate was 10.2% in septuagenarians and 12.5% in octogenarians (p = 0.74). Multivariate analysis identified prolonged ventilation (≥ 72 h) as a significant risk factor for hospital mortality. Being an octogenarian was not significantly associated with hospital mortality. The actuarial survival rate at 5 years was 80.1% in septuagenarians and 58.5% in octogenarians (log-rank p = 0.09). The freedom from aortic event rate at 5 years was 91.0% in septuagenarians and 100% in octogenarians (log-rank p = 0.23). CONCLUSION: The two groups showed no significant differences in hospital mortality or morbidity. Our tear-oriented strategies might be appropriate for both septuagenarians and octogenarians. Prolonged ventilation (≥ 72 h) was a significant risk predictor for hospital mortality.


Subject(s)
Aortic Dissection , Octogenarians , Age Factors , Aged, 80 and over , Aortic Dissection/diagnostic imaging , Aortic Dissection/surgery , Hospital Mortality , Humans , Postoperative Complications , Retrospective Studies , Risk Factors , Treatment Outcome
3.
Asian J Endosc Surg ; 15(1): 230-234, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34056860

ABSTRACT

INTRODUCTION: For patients who have acute severe cholecystitis, urgent/early biliary drainage followed by delayed/elective laparoscopic cholecystectomy is recommended according to the Tokyo Guidelines 2018. Percutaneous transhepatic gallbladder drainage is an established technique. Recently, transmural gallbladder drainage under the guidance of endoscopic ultrasonography (EUS-GBD) was reported as a safe alternative. During surgery, fluorescence imaging using indocyanine green (ICG) has been increasingly used for visualizing the bile ducts. Herein, we report a sequential treatment approach which ensures safety without impairing normal activities before cholecystectomy: EUS-GBD followed by laparoscopic cholecystectomy using ICG fluorescence imaging. MATERIALS AND SURGICAL TECHNIQUE: A 66-year-old man with acute cholecystitis underwent urgent EUS-GBD and had the drainage tube placement through the duodenum into the gallbladder. During 2.5 months of the waiting period, he had no clinical troubles. After insertion of a laparoscope, we found a structure between the gallbladder and the duodenum. We injected 0.025 mg/mL of ICG into the nasobiliary drainage tube (placed in the gallbladder through the duodenum) and confirmed that the structure was a fistula. After removing the tube, the fistula was divided using a surgical stapler under the guidance of fluorescence imaging. The cystic and common bile ducts were also clearly visualized as fluorescence. DISCUSSION: We reported a safe sequential treatment approach for the patient who required biliary drainage: EUS-GBD followed by laparoscopic cholecystectomy under the guidance of ICG fluorescence imaging. This sequential approach may improve patients' satisfaction with respect to quality of life during the waiting period and may ensure the safety of laparoscopic cholecystectomy.


Subject(s)
Cholecystectomy, Laparoscopic , Cholecystitis, Acute , Aged , Cholecystitis, Acute/diagnostic imaging , Cholecystitis, Acute/surgery , Drainage , Gallbladder , Humans , Inflammation , Male , Optical Imaging , Quality of Life , Treatment Outcome
5.
Pediatr Cardiol ; 41(7): 1492-1500, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32638042

ABSTRACT

The aim of this study was to analyze the aortic arch repair technique for preserving the lesser curvature without cardiopulmonary bypass through a left thoracotomy in neonates with coarctation of the aorta (CoA) and a hypoplastic distal aortic arch (HDAA). HDAA was defined as z-score of the aortic arch < - 2.5. Twenty-four neonates with CoA and HDAA were retrospectively studied. Patients underwent enlargement of the HDAA associated with CoA repair when their z-scores were < - 4. They were divided into 2 groups on the basis of the preoperative z-score of the distal aortic arch: group 1 (n = 14), z-score ≥ - 4; group 2 (n = 10), z-score < - 4. Twenty-two patients had intracardiac defects. Follow-up ranged from 0.9 to 20.1 years (median 11.6 years). The z-scores of the distal aortic arch were significantly smaller in group 2 than group 1 (- 5.09 ± 1.05 vs - 3.19 ± 0.36, p < 0.001). There were no hospital deaths and no hypertension. All dimensions of the aortic arch in both groups revealed significant catch-up growth (p < 0.02). All patients showed a pressure gradient ≤ 5 mmHg across the aortic arch and between the arms and legs at the latest follow-up. Two patients showed an angulated arch deformity over 10 years later. This technique provided good catch-up growth and a low incidence of reobstruction and deformity of reconstructed aortic arch in both groups. These results suggest that this modification might be considered as one choice of technique for CoA and HDAA.


Subject(s)
Aorta, Thoracic/growth & development , Aortic Coarctation/surgery , Thoracotomy/methods , Vascular Surgical Procedures/methods , Aorta, Thoracic/pathology , Female , Humans , Infant, Newborn , Male , Retrospective Studies
6.
J Endovasc Ther ; 27(5): 828-835, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32436809

ABSTRACT

PURPOSE: To evaluate the feasibility and safety of sac embolization with N-butyl cyanoacrylate (NBCA) in emergency endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm (AAA) and iliac artery aneurysm (IAA) in comparison to EVAR without sac embolization. MATERIALS AND METHODS: Between February 2012 and December 2019, among 44 consecutive patients with ruptured AAA or IAA, 29 underwent EVAR. Of these, 22 patients (median age 77.5 years; 18 men) had concomitant sac embolization using NBCA; the remaining 7 patients (median age 88 years; 6 men) underwent EVAR without sac embolization and form the control group. The technical success, clinical success (hemodynamic stabilization), procedure-related complications, and mortality were compared between the groups. RESULTS: All EVAR procedures and embolizations were successful. The clinical success rates in the NBCA and control groups were 95% (21/22) and 71% (5/7), respectively (p=0.14). There was no complication related to the procedure. Type II endoleak occurred in 4 of 21 patients (19%) in the NBCA group vs none of the control patients. One patient (5%) died in the NBCA group vs 3 (43%) in the controls (p=0.034). CONCLUSION: Sac embolization using NBCA in emergency EVAR appears to be feasible and safe for ruptured AAA and IAA.


Subject(s)
Aortic Aneurysm, Abdominal/therapy , Aortic Rupture/therapy , Blood Vessel Prosthesis Implantation , Embolization, Therapeutic , Enbucrilate/administration & dosage , Endovascular Procedures , Iliac Aneurysm/therapy , Aged , Aged, 80 and over , Aortic Aneurysm, Abdominal/diagnostic imaging , Aortic Aneurysm, Abdominal/physiopathology , Aortic Rupture/diagnostic imaging , Aortic Rupture/physiopathology , Blood Vessel Prosthesis Implantation/adverse effects , Embolization, Therapeutic/adverse effects , Emergencies , Enbucrilate/adverse effects , Endovascular Procedures/adverse effects , Feasibility Studies , Female , Humans , Iliac Aneurysm/diagnostic imaging , Iliac Aneurysm/physiopathology , Male , Retrospective Studies , Risk Factors , Time Factors , Treatment Outcome
7.
Ann Vasc Dis ; 13(4): 457-460, 2020 Dec 25.
Article in English | MEDLINE | ID: mdl-33391572

ABSTRACT

A 75-year-old man underwent emergent endovascular aortic repair for a ruptured abdominal aortic aneurysm. Two years later, computed tomography revealed aneurysm enlargement with endoleaks. Next, late open conversion was performed. Intraoperatively, we detected a spurting type II endoleak from an artery within the aneurysmal wall, which was unconnected to any branch vessels outside the aneurysm, and surgical ligation and sacotomy was performed uneventfully. To our knowledge, this is the first report to intraoperatively identify a type II endoleak from an artery within the aneurysm wall. Even for atypical type II endoleak, such as this case, open surgical repair should be effective.

8.
Sci Rep ; 9(1): 18859, 2019 12 11.
Article in English | MEDLINE | ID: mdl-31827136

ABSTRACT

Metabolism is a critical regulator of cell fate determination. Recently, the significance of metabolic reprogramming in environmental adaptation during tumorigenesis has attracted much attention in cancer research. Recurrent mutations in the isocitrate dehydrogenase (IDH) 1 or 2 genes have been identified in several cancers, including intrahepatic cholangiocarcinoma (ICC). Mutant IDHs convert α-ketoglutarate (α-KG) to 2-hydroxyglutarate (2-HG), which affects the activity of multiple α-KG-dependent dioxygenases including histone lysine demethylases. Although mutant IDH can be detected even in the early stages of neoplasia, how IDH mutations function as oncogenic drivers remains unclear. In this study, we aimed to address the biological effects of IDH1 mutation using intrahepatic biliary organoids (IBOs). We demonstrated that mutant IDH1 increased the formation of IBOs as well as accelerated glucose metabolism. Gene expression analysis and ChIP results revealed the upregulation of platelet isoform of phosphofructokinase-1 (PFKP), which is a rate-limiting glycolytic enzyme, through the alteration of histone modification. Knockdown of the Pfkp gene alleviated the mutant IDH1-induced increase in IBO formation. Notably, the high expression of PFKP was observed more frequently in patients with IDH-mutant ICC compared to in those with wild-type IDH (p < 0.01, 80.9% vs. 42.5%, respectively). Furthermore, IBOs expressing mutant IDH1 survived the suppression of ATP production caused by growth factor depletion and matrix detachment by retaining high ATP levels through 5' adenosine monophosphate-activated protein kinase (AMPK) activation. Our findings provide a systematic understanding as to how mutant IDH induces tumorigenic preconditioning by metabolic rewiring in intrahepatic cholangiocytes.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Biliary Tract/metabolism , Isocitrate Dehydrogenase/genetics , Mutation , Phosphofructokinase-1/metabolism , AMP-Activated Protein Kinases/genetics , Animals , Citric Acid Cycle , Gene Expression Regulation , Glutarates/metabolism , Humans , Isocitrate Dehydrogenase/metabolism , Ketoglutaric Acids/metabolism , Mice , Phosphofructokinase-1/genetics
10.
J Hepatobiliary Pancreat Sci ; 26(3): E3-E4, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30786172

ABSTRACT

Highlight Ogura and colleagues present a novel electrocautery dilation device for endoscopic ultrasound-guided procedures. The distal end of the outer dilator contains a 3-Fr metal tip, allowing a smaller burning effect than with conventional devices. This novel device may have clinical impact for endoscopic ultrasound-guided procedures as tract dilation device.


Subject(s)
Bile Ducts, Intrahepatic/surgery , Cholestasis/therapy , Dilatation/instrumentation , Electrocoagulation/instrumentation , Endosonography , Dilatation/methods , Electrocoagulation/methods , Humans , Ultrasonography, Interventional
11.
J Infect Chemother ; 25(6): 473-476, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30738726

ABSTRACT

Bacterial peritonitis, an infection of the ascitic fluid, can be classified etiologically as spontaneous or secondary bacterial peritonitis. The former is mainly caused by portal hypertension and its subsequent effects, whereas the latter is caused by the direct dissemination of bacteria into the peritoneal cavity. Previous reports have described some distinguishing features of these two entities. Here, we report the first known case of bacterial peritonitis with Aeromonas hydrophilia and Escherichia coli in a patient with malignant ascites associated with pancreatic carcinoma who exhibited features of both spontaneous and secondary peritonitis. Our report suggests that clinicians should also consider bacterial peritonitis in patients with malignant ascites who present with ostensibly cancer-related symptoms.


Subject(s)
Ascites/etiology , Ascitic Fluid/microbiology , Bacterial Infections/diagnosis , Pancreatic Neoplasms/complications , Peritonitis/diagnosis , Aeromonas hydrophila/isolation & purification , Anti-Bacterial Agents/therapeutic use , Ascites/diagnostic imaging , Ascites/therapy , Bacterial Infections/microbiology , Bacterial Infections/therapy , Drainage , Escherichia coli/isolation & purification , Humans , Male , Middle Aged , Peritonitis/microbiology , Peritonitis/therapy , Piperacillin, Tazobactam Drug Combination/therapeutic use , Tomography, X-Ray Computed , Pancreatic Neoplasms
12.
J Gastrointest Surg ; 22(9): 1528-1537, 2018 09.
Article in English | MEDLINE | ID: mdl-29766443

ABSTRACT

BACKGROUNDS: We aimed to investigate the diagnostic accuracy of multidetector-row computed tomography (MDCT), mapping biopsy, and other imaging modalities to predict the longitudinal extension and depth of invasion of extrahepatic cholangiocarcinoma at possible surgical ductal margins. METHODS: Of 102 patients with surgical resection of extrahepatic cholangiocarcinoma between January 2010 and October 2015, 32 evaluated by multidetector-row computed tomography (MDCT) performed before biliary drainage and mapping biopsy were enrolled. Mapping biopsies were performed at 74 sites to determine the resection point of the bile duct (at 74 possible surgical ductal margins). Diagnostic accuracy was evaluated by histopathology. RESULTS: The diagnostic accuracy of MDCT for longitudinal cancer spread was 79.7%, that of biopsy was 73.0%, and combining the two modalities showed highest accuracy (83.8%). The depth of tumor invasion could be predicted by combination of the ductal wall thickness and contrast enhancement on MDCT, that is, at 11 of 13 sites (84.6%) with submucosal invasion, ductal wall thickness was > 2.5 mm with high contrast enhancement. CONCLUSIONS: MDCT demonstrated highest accuracy of diagnosing longitudinal extension at possible surgical ductal margins in patients with extrahepatic cholangiocarcinoma. The depth of tumor invasion could be predicted by ductal wall thickness and contrast enhancement of MDCT.


Subject(s)
Bile Duct Neoplasms/diagnostic imaging , Bile Duct Neoplasms/pathology , Cholangiocarcinoma/diagnostic imaging , Cholangiocarcinoma/pathology , Multidetector Computed Tomography , Aged , Bile Duct Neoplasms/surgery , Bile Ducts, Extrahepatic , Biopsy , Cholangiocarcinoma/surgery , Cholangiography , Endoscopy, Digestive System , Female , Humans , Male , Margins of Excision , Middle Aged , Neoplasm Invasiveness , Retrospective Studies
13.
Cardiol Young ; 26(7): 1391-6, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26821376

ABSTRACT

BACKGROUND: Surgical repair for cardiac lesions has rarely been offered to patients with trisomy 18 because of their very short lifespans. We investigated the effectiveness of cardiac surgery in patients with trisomy 18. Patients and methods We performed a retrospective analysis of 20 consecutive patients with trisomy 18 and congenital cardiac anomalies who were evaluated between August, 2003 and July, 2013. All patients developed respiratory or cardiac failure due to excessive pulmonary blood flow. Patients were divided into two subgroups: one treated surgically (surgical group, n=10) and one treated without surgery (conservative group, n=10), primarily to compare the duration of survival between the groups. RESULTS: All the patients in the surgical group underwent cardiac surgery with pulmonary artery banding, including patent ductus arteriosus ligation in nine patients and coarctation repair in one. The duration of survival was significantly longer in the surgical group than in the conservative group (495.4±512.6 versus 93.1±76.2 days, respectively; p=0.03). A Cox proportional hazard model found cardiac surgery to be a significant predictor of survival time (risk ratio of 0.12, 95% confidence interval 0.016-0.63; p=0.01). CONCLUSIONS: Cardiac surgery was effective in prolonging survival by managing high pulmonary blood flow; however, the indication for surgery should be carefully considered on a case-by-case basis, because the risk of sudden death remains even after surgery. Patients' families should be provided with sufficient information to make decisions that will optimise the quality of life for both patients and their families.


Subject(s)
Cardiac Surgical Procedures , Heart Defects, Congenital/complications , Heart Defects, Congenital/mortality , Heart Defects, Congenital/therapy , Trisomy/genetics , Vascular Surgical Procedures , Chromosomes, Human, Pair 18/genetics , Female , Humans , Infant , Infant, Newborn , Japan , Kaplan-Meier Estimate , Male , Multivariate Analysis , Proportional Hazards Models , Quality of Life , Retrospective Studies , Treatment Outcome , Trisomy 18 Syndrome
14.
Best Pract Res Clin Gastroenterol ; 29(4): 601-10, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26381305

ABSTRACT

Pancreatic cystic lesions (PCLs) are increasingly identified with the widespread use of imaging modalities. The precise diagnosis of PCLs remains a challenge despite the use of CT, MRI, and EUS-FNA. Confocal laser endomicroscopy (CLE) is a new endoscopic imaging modality that provides real-time, very high magnification images. A smaller CLE probe, which can be passed through a 19-gauge FNA needle, is now available. Needle-based CLE during EUS has recently been examined to evaluate PLCs, and the specific criteria of nCLE for the diagnosis of PLCs have been proposed.


Subject(s)
Endoscopic Ultrasound-Guided Fine Needle Aspiration/methods , Neoplasms, Cystic, Mucinous, and Serous/diagnosis , Pancreatic Cyst/diagnosis , Pancreatic Neoplasms/diagnosis , Humans , Microscopy, Confocal/instrumentation
15.
Gut Liver ; 8(5): 563-8, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25228979

ABSTRACT

BACKGROUND/AIMS: To determine the nutritional markers important for assessing the degree of pancreatic insufficiency due to chronic pancreatitis in routine clinical practice. METHODS: A total of 137 patients with chronic pancreatitis were followed up for more than 1 year. They were divided into two groups: a pancreatic diabetes mellitus (DM) group, consisting of 47 patients undergoing medical treatment for DM of pancreatic origin, and a nonpancreatic DM group, consisting of 90 other patients (including 86 patients without DM). Serum albumin, prealbumin, total cholesterol, cholinesterase, magnesium, and hemoglobin were compared between the two groups. RESULTS: The total cholesterol was significantly lower in the pancreatic than the nonpancreatic DM group (164 mg/dL vs 183 mg/dL, respectively; p=0.0028). Cholinesterase was significantly lower in the former group (263 U/L vs 291 U/L, respectively; p=0.016). Among the 37 patients with nonalcoholic pancreatitis, there was no difference in the cholinesterase levels between the pancreatic and nonpancreatic (296 U/L vs 304 U/L, respectively; p=0.752) DM groups, although cholesterol levels remained lower in the former (165 mg/dL vs 187 mg/dL, respectively; p=0.052). CONCLUSIONS: Cholinesterase levels are possibly affected by concomitant alcoholic liver injury. The total cholesterol level should be considered when assessing pancreatic insufficiency due to chronic pancreatitis.


Subject(s)
Cholesterol/blood , Exocrine Pancreatic Insufficiency/blood , Pancreatitis, Chronic/complications , Adult , Aged , Aged, 80 and over , Cholinesterases/blood , Diabetes Mellitus, Type 2/complications , Exocrine Pancreatic Insufficiency/etiology , Female , Follow-Up Studies , Humans , Liver Cirrhosis, Alcoholic/blood , Male , Middle Aged , Nutritional Status , Pancreas/enzymology , Pancreatitis, Alcoholic/blood , Pancreatitis, Alcoholic/complications , Pancreatitis, Chronic/blood , Serum Albumin/analysis
16.
Asian Cardiovasc Thorac Ann ; 22(4): 481-3, 2014 May.
Article in English | MEDLINE | ID: mdl-24771741

ABSTRACT

A 3-year-old boy with pulmonary atresia with ventricular septal defect, who had undergone placement of a modified Blalock-Taussig shunt, presented with a 1-week history of high fever. Computed tomography showed a pseudoaneurysm at the anastomosis between the right brachiocephalic artery and the graft. After intravenous antibiotic therapy, the pseudoaneurysm and infected graft were resected through a median sternotomy. This report describes successful management of a potentially fatal complication following placement of a modified Blalock-Taussig shunt.


Subject(s)
Aneurysm, False/microbiology , Aneurysm, Infected/microbiology , Blalock-Taussig Procedure/adverse effects , Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis/adverse effects , Heart Septal Defects/surgery , Pneumococcal Infections/microbiology , Pulmonary Atresia/surgery , Administration, Intravenous , Aneurysm, False/diagnosis , Aneurysm, False/therapy , Aneurysm, Infected/diagnosis , Aneurysm, Infected/therapy , Anti-Bacterial Agents/administration & dosage , Blalock-Taussig Procedure/instrumentation , Blood Vessel Prosthesis Implantation/instrumentation , Child, Preschool , Combined Modality Therapy , Device Removal , Heart Septal Defects/diagnosis , Humans , Male , Pneumococcal Infections/diagnosis , Pneumococcal Infections/therapy , Pulmonary Atresia/diagnosis , Reoperation , Sternotomy , Tomography, X-Ray Computed , Treatment Outcome
18.
Interact Cardiovasc Thorac Surg ; 17(3): 586-7, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23739322

ABSTRACT

An aneurysm of the left atrial appendage is an extremely rare anomaly that is commonly associated with supraventricular arrhythmia, compression of the coronary arteries, intracardiac thrombus and pulmonary venous stenosis. This condition may be caused by congenital dysplasia of the musculi pectinati and is usually diagnosed in the second to fourth decades of life. We report the surgical management of an asymptomatic 9-year old girl with this anomaly. She was referred to us because of abnormal chest X-ray findings, and investigation revealed an aneurysm of the left atrial appendage. As this condition may have potentially fatal complications, the aneurysm was completely resected under cardiac arrest with cardiopulmonary bypass to prevent recurrence and thrombus formation. We suggest that resection of an aneurysm of the left atrial appendage under cardiac arrest with cardiopulmonary bypass is a reasonable treatment option to prevent potential complications, particularly in children.


Subject(s)
Atrial Appendage/surgery , Cardiac Surgical Procedures , Heart Aneurysm/surgery , Asymptomatic Diseases , Atrial Appendage/diagnostic imaging , Cardiopulmonary Bypass , Child , Female , Heart Aneurysm/complications , Heart Aneurysm/diagnosis , Heart Arrest, Induced , Humans , Tomography, X-Ray Computed , Treatment Outcome
19.
Gastrointest Endosc Clin N Am ; 22(2): 379-85, xi, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22632959

ABSTRACT

Recent advances in hepatology have included a new and effective treatment of viral hepatitis, with an increased need for the assessment of liver function and histology. At the same time, there have been a growing number of endoscopic procedures that are pertinent to patients with liver disease. It would be ideal if the assessment and treatment of liver disease and portal hypertension could be performed and assimilated by the liver/gastrointestinal specialist. The authors like to consider this area of integration or overlap of endoscopic procedures within the practice of hepatology as endo-hepatology.


Subject(s)
Endoscopy , Gastroenterology , Liver Diseases/diagnosis , Liver Diseases/therapy , Ultrasonography, Interventional , Ascites/diagnostic imaging , Biopsy, Fine-Needle , Endosonography , Esophageal and Gastric Varices/therapy , Humans , Liver Diseases/diagnostic imaging , Paracentesis/methods
20.
Opt Express ; 19(7): 6303-11, 2011 Mar 28.
Article in English | MEDLINE | ID: mdl-21451656

ABSTRACT

The novel red-emitting phosphors of Eu3+-activated Ca2RF4PO4:Eu3+ (R=Gd, Y) prepared by a solid-state reaction have been evaluated as a candidate for white solid state lighting. The detailed luminescence properties, e.g., the excitation spectra, the luminescence spectra and quantum efficiency under the excitation of near-UV, and decay lifetimes were reported. The phosphors can be efficiently excited by near UV light and exhibit a dominant emission peaked at 611 nm (5D0-7F2) with CIE coordinates of (x=0.661, y=0.333). The thermal stabilities were investigated from the luminescence intensities, color purity and the decay curves by increasing temperature. The luminescence parameters related to white LEDs applications were compared to some red phosphors and discussed in details. The red-emitting Ca2RF4PO4:Eu3+ (R=Gd, Y) may be potentially useful in the fabrication of white LEDs.


Subject(s)
Fluorine/chemistry , Lighting/instrumentation , Oxides/chemistry , Semiconductors , Color , Equipment Design , Equipment Failure Analysis
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