A Molecular-Switch-Embedded Organic Photodiode for Capturing Images against Strong Backlight.

When the intensity of the incident light increases, the photocurrents of organic photodiodes (OPDs) exhibit relatively early saturation, due to which OPDs cannot easily detect objects against strong backlights, such as sunlight. In this study, this problem is addressed by introducing a light-intensity-dependent transition of the operation mode, such that the operation mode of the OPD autonomously changes to overcome early photocurrent saturation as the incident light intensity passes the threshold intensity. The photoactive layer is doped with a strategically designed and synthesized molecular switch, 1,2-bis-(2-methyl-5-(4-cyanobiphenyl)-3-thienyl)tetrafluorobenzene (DAB). The proposed OPD exhibits a typical OPD performance with an external quantum efficiency (EQE) of <100% and a photomultiplication behavior with an EQE of >100% under low-intensity and high-intensity light illuminations, respectively, thereby resulting in an extension of the photoresponse linearity to a light intensity of 434 mW cm-2 . This unique and reversible transition of the operation mode can be explained by the unbalanced quantum yield of photocyclization/photocycloreversion of the molecular switch. The details of the operation mechanism are discussed in conjunction with various photophysical analyses. Furthermore, they establish a prototype image sensor with an array of molecular-switch-embedded OPD pixels to demonstrate their extremely high sensitivity against strong light illumination.

Organizing Thrombus Mimicking a Cardiac Tumor Located at the Mitral-Aortic Intervalvular Fibrosa.

Thrombosis at the left ventricular outflow tract occurs without any detectable heart disease or predisposing factors only extremely rarely. A 48-year-old male visited Konkuk University Medical Center with loss of consciousness one month prior to presentation. Before he visited our hospital, he had been diagnosed with a cardiac tumor, which was located between the left atrium and posterior aortic root, and which was adjacent to both the aortic and mitral valves. Cardiac transplantation was recommended at the other hospital because of the high risk of cardiac dysfunction induced by both aortic and mitral valvular dysfunction after surgical resection. Based on preoperative transthoracic echocardiography, cardiac computed tomography, cardiac magnetic resonance imaging, and intra-operative transesophageal echocardiography, we considered it to be a benign tumor. Complete resection was achieved and the pathology confirmed organizing thrombus. We report a case of organizing thrombus mimicking a cardiac tumor, which was located at the mitral-aortic intervalvular fibrosa of the left ventricular outflow tract without any heart disease.

Isolation of the Left Subclavian Artery with Right Aortic Arch in Association with Bilateral Ductus Arteriosus and Ventricular Septal Defect.

Right aortic arch with isolation of the left subclavian artery is a rare anomaly. The incidence of bilateral ductus arteriosus is sporadic, and a right aortic arch with isolation of the left subclavian artery in association with bilateral ductus arteriosus is therefore extremely rare. Since the symptoms and signs of isolation of the left subclavian artery can include the absence or underdevelopment of the left arm, subclavian steal syndrome, or pulmonary artery steal syndrome, the proper therapeutic approach is controversial. We report a case in which surgical reconstruction was used to treat isolation of the left subclavian artery with right aortic arch in association with bilateral ductus arteriosus and a ventricular septal defect.

Clinical Analysis of Radiocephalic Fistula Using Side-to-side Anastomosis with Distal Cephalic Vein Ligation.

BACKGROUND: The surgically created arteriovenous fistula has recently been recommended as the best available angioaccess for hemodialysis. Therefore, in this study, we carried out a clinical analysis on surgical procedures in the ligation and division of a distal vein to achieve similar effects as those of vein end-to-arterial side after side-to-side anastomosis. METHODS: We retrospectively reviewed the clinical data of 113 patients who came for an outpatient clinic follow-up to the department of internal medicine of our hospital; these patients were among the 125 patients who underwent radiocephalic arteriovenous fistula (side-to-side anastomosis with distal vein ligation and division) in our hospital in the period from January 2006 to December 2010. RESULTS: The patency rate showed no statistical significance with respect to sex (p=0.775), age (p=0.775), hypertension (p=0.262), diabetes (p=0.929), and cardio-neurovascular disease (p=0.717). Patency rates were 96% for the first month, 93% for the first year, and 90% for the second year for the radiocephalic arteriovenous fistula (side-to-side anastomosis with distal vein ligation and division) performed on the wrist. CONCLUSION: The patency rates revealed favorable results and few postoperative complications as compared to those of previous reports. Therefore, radiocephalic fistula using side-to-side anastomosis with distal cephalic vein ligation is considered a recommendable surgical procedure in the distal part for the hemodialysis of CRF patients.

Primary surgical closure should be considered in premature neonates with large patent ductus arteriosus.

BACKGROUND: Treatment for patent ductus arteriosus (PDA) in premature infants can consist of medical or surgical approaches. The appropriate therapeutic regimen remains contentious. This study evaluated the role of surgery in improving the survival of premature neonates weighing less than 1,500 g with PDA. MATERIALS AND METHODS: From January 2008 to June 2011, 68 patients weighing less than 1,500 g with PDA were enrolled. The patients were divided into three groups: a group managed only by medical treatment (group I), a group requiring surgery after medical treatment (group II), and a group requiring primary surgical treatment (group III). RESULTS: The rate of conversion to surgical methods due to failed medical treatment was 67.6% (25/37) in the patients with large PDA (≥2 mm in diameter). The number of patients who could be managed with medical treatment was nine which was only 20.5% (9/44) of the patients with large PDA. There was no surgery-related mortality. Group III displayed a statistically significantly low rate of development of bronchopulmonary dysplasia (BPD) (p=0.008). The mechanical ventilation time was significantly longer in group II (p=0.002). CONCLUSION: Medical treatment has a high failure rate in infants weighing less than 1,500 g with PDA exceeding 2.0 mm. Surgical closure following medical treatment requires a longer mechanical ventilation time and increases the incidence of BPD. Primary surgical closure of PDA exceeding 2.0 mm in the infants weighing less than 1,500 g should be considered to reduce mortality and long-term morbidity events including BPD.