712 research outputs found
On the dynamical nature of the active center in a single-site photocatalyst visualized by 4D ultrafast electron microscopy
Understanding the dynamical nature of the catalytic active site embedded in complex systems at the atomic level is critical to developing efficient photocatalytic materials. Here, we report, using 4D ultrafast electron microscopy, the spatiotemporal behaviors of titanium and oxygen in a titanosilicate catalytic material. The observed changes in Bragg diffraction intensity with time at the specific lattice planes, and with a tilted geometry, provide the relaxation pathway: the Ti^(4+)=O^(2β) double bond transformation to a Ti^(3+)βO^(1β) single bond via the individual atomic displacements of the titanium and the apical oxygen. The dilation of the double bond is up to 0.8 Γ
and occurs on the femtosecond time scale. These findings suggest the direct catalytic involvement of the Ti^(3+)βO^(1β) local structure, the significance of nonthermal processes at the reactive site, and the efficient photo-induced electron transfer that plays a pivotal role in many photocatalytic reactions
The effect of sustained-release CARvedilol in patients with hypErtension and heart failure with preserved ejection fraction: a study protocol for a pilot randomized controlled trial (CARE-preserved HF)
BackgroundAlthough beta-blockers improve clinical outcomes in heart failure with reduced ejection fraction, the benefit of beta-blockers in heart failure with preserved ejection fraction (HFpEF) is uncertain. Global longitudinal strain (GLS) is a robust predictor of heart failure outcomes, and recent studies have shown that beta-blockers are associated with improved survival in those with low GLS (GLS <14%) but not in those with GLS β₯14% among patients with LVEF β₯40%. Therefore, the objective of this trial is to evaluate the effect of sustained-release carvedilol (carvedilol-SR) on the outcome [N-terminal pro-B-natriuretic peptide (NT-proBNP) concentration] in patients with hypertension and HFpEF and will assess the differential effects of these drugs on the outcome, according to the GLS categories.MethodsThis prospective randomized double-blind multicenter trial (CARE-preserved HF) will include 100 patients with HFpEF from three tertiary hospitals in South Korea. Patients with HFpEF and hypertension aged β₯20 years who have evidence of functional and structural heart disease on echocardiography and elevated natriuretic peptide will be enrolled. Eligible participants will be randomized 1:1 to either the carvedilol-SR group (nβ=β50) or the placebo group (nβ=β50). Patients in the carvedilol-SR group will receive 8, 16, 32, or 64β
mg carvedilol-SR once daily for 6 months, and the dose of carvedilol will be up-titrated at the discretion of the treating physicians. The primary efficacy outcome was the time-averaged proportional change in N-terminal pro-B-natriuretic peptide concentration from baseline to months 3 and 6. We will also evaluate the differential effects of carvedilol-SR on primary outcomes according to GLS, using a cut-off of 14% or the median value.DiscussionThis randomized controlled trial will investigate the efficacy and safety of carvedilol-SR in patients with HFpEF and hypertension.
Clinical Trial RegistrationClinicalTrial.gov, identifier NCT05553314
Electro-Mechanical Safety Testing of Portable ECG Devices for Home Healthcare Usage
OBJECTIVES: This paper suggests the experimental guidelines to evaluate the electro-mechanical safety of belt type equipment. The electro-mechanical safety was determined by using the International Electrotechnical Commission guidelines, which are widely used as important factors for assessing the electro-mechanical safety of belt type equipment. However, the local guidelines on wearable healthcare sensors are currently not well-established. Therefore, safety guidelines suited for the actual circumstances in Korea are required, and this paper attempts to try a new experimental safety test procedure of the wearable healthcare sensor. METHODS: This belt type device measures the electrocardiogram (ECG) and heart rates by attaching to the chest. Examination lists were selected by analyzing the common standards ofelectro-mechanical safety (IEC 60601-1) and environment tests (IEC 60068-1, IEC 60068-2) of home-healthcare equipment. RESULTS: The essential electrical safety, which was required for the RS300G3 as a medical device, was evaluated, and most of the examination lists were selected by considering the circumstances of the users. The device passed all the selected examinable lists that are applicable to the Korean environment. CONCLUSIONS: This study has limitations to estimate and to conduct electro-mechanical safety experiments because our study focused on the belt type of heart-rates equipment. We are not taking into account the overall electro-mechanical home-healthcare measurements. According to industrial and technological development, there are infinite possibilities for the advancement of home-healthcare equipment, so more examination lists for safety are being added in addition to what we have doneope
Carbonic anhydrase XII expression is associated with histologic grade of cervical cancer and superior radiotherapy outcome
BACKGROUND: To investigate whether expression of carbonic anhydrase XII (CA12) is associated with histologic grade of the tumors and radiotherapy outcomes of the patients with invasive cervical cancer. METHODS: CA12 expression was examined by immunohistochemical stains in cervical cancer tissues from 183 radiotherapy patients. Histological grading was classified as well (WD), moderately (MD) or poorly differentiated (PD). Oligonucleotide microarray experiment was performed using seven cervical cancer samples to examine differentially expressed genes between WD and PD cervical cancers. The association between CA12 and histological grade was analyzed by chi-square test. CA12 and histological grades were analyzed individually and as combined CA12 and histologic grade categories for effects on survival outcome. RESULTS: Immunohistochemical expression of CA12 was highly associated with the histologic grade of cervical cancer. Lack of CA12 expression was associated with PD histology, with an odds ratio of 3.9 (P = 0.01). Microarray analysis showed a fourfold reduction in CA12 gene expression in PD tumors. CA12 expression was marginally associated with superior disease-free survival. Application of the new combined categories resulted in further discrimination of the prognosis of patients with moderate and poorly differentiated tumor grade. CONCLUSIONS: Our study indicates that CA12 may be used as a novel prognostic marker in combination with histologic grade of the tumors
Feasibility of the Radial Artery as a Vascular Access Route in Performing Primary Percutaneous Coronary Intervention
We aimed to evaluate the feasibility of transradial primary percutaneous coronary intervention (PCI) in patients with ST elevation myocardial infarction (STEMI) by comparing the procedural results and complications with those of transfemoral intervention. From April 1997 to October 2004, we enrolled 352 consecutive cases of STEMI who underwent primary PCI. The femoral route was used in 132 cases (TFI group) and the radial route was used in 220 cases (TRI group). Cases with Killips class IV, a negative Allen test or a non-palpable radial artery were excluded from our study. Baseline clinical and angiographic profiles were comparable in both groups. Vascular access time was 3.8 Β± 3.5 min in the TFI group and 3.6 Β± 3.1 min in the TRI group, and cath room to reperfusion time was 25 Β± 11 min in the TRI group and 26 Β± 13 min in the TRI group. The procedural success rate was 89% in the TFI group and 88% in the TRI group. Crossover occurred in 9 cases (4%) due to approaching vessel tortuosity in the TRI group. Major access site complications occurred in 7 cases (5%) in the TFI group, and there were no complications in the TRI group (p < 0.001). Although radial occlusion occurred in 5 cases of the TRI group, there was no evidence of hand ischemia. The total hospital stay was significantly shorter in TRI group than in TFI group. In conclusion, use of the radial artery might be a potential vascular access route in performing primary PCI in selected cases
Impact of successful restoration of sinus rhythm in patients with atrial fibrillation and acute heart failure: Results from the Korean Acute Heart Failure registry
Background: Restoring and maintaining sinus rhythm (SR) in patients with atrial fibrillation (AF) failed to show superior outcomes over rate control strategies in prior randomized trials. However, there is sparse data on their outcomes in patients with acute heart failure (AHF).Methods: From December 2010 to February 2014, 5,625 patients with AHF from 10 tertiary hospitals were enrolled in the Korean Acute Heart Failure registry, including 1,961 patients whose initial electrocardiogram showed AF. Clinical outcomes of patients who restored SR by pharmacological or electrical cardioversion (SR conversion group, n = 212) were compared to those of patients who showed a persistent AF rhythm (AF persistent group, n = 1,662).Results: All-cause mortality both in-hospital and during the follow-up (median 2.5 years) were significantly lower in the SR conversion group than in the AF persistent group after adjustment for risk factors (adjusted hazard ratio [HR]; 95% confidence interval [CI] = 0.26 [0.08β0.88], p = 0.031 and 0.59 [0.43β0.82], p = 0.002, for mortality in-hospital and during follow-up, respectively). After 1:3 propensity score matching (SR conversion group = 167, AF persistent group = 501), successful restoration of SR was associated with lower all-cause mortality (HR [95% CI] = 0.68 [0.49β0.93], p = 0.015), heart failure rehospitalization (HR [95% CI] = 0.66 [0.45β0.97], p = 0.032), and composite of death and heart failure rehospitalization (HR [95% CI] = 0.66 [0.51β0.86], p = 0.002).Conclusions: Patients with AHF and AF had significantly lower mortality in-hospital and during follow-up if rhythm treatment for AF was successful, underscoring the importance of restoring SR in patients with AHF
Broken Guidewire Fragment in the Radio-brachial Artery During Transradial Sheath Placement: Percutaneous Retrieval via Femoral Approach
A case in which a 0.014" wire was broken during the sheath placement in the radial artery for transradial coronary procedure is described here, and a successful retrieval of it using conventional methods is also described. Through the left femoral artery, the 6 Fr guiding catheter was advanced down to the tip of the broken wire at the brachial artery, and the distal part of the broken guidewire was captivated into the guiding catheter. By inflating the balloon catheter inside of the guiding catheter, seized broken guidewire between the inflated balloon and the guiding catheter was removed successfully by withdrawing the whole system en bloc
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