Unusual presentation of asymptomatic subacute lead-related ventricular perforation beyond the pericardium without pericardial effusion: a case report.

The clinical manifestations of subacute pacemaker lead-related cardiac perforations are highly variable. Patients with subacute perforations can present with a variety of symptoms, whereas those with acute perforations usually present with cardiac tamponade that necessitates emergent pericardiocentesis. A 32-year-old woman underwent pacemaker implantation for sick sinus syndrome. An active-fixation atrial lead was fixed to the right atrial appendage, and a ventricular lead was fixed to the right ventricle (RV) apex, with acceptable parameters. Two weeks postoperative, the patient visited the clinic for routine examination of the pacemaker parameters. Chest X-ray showed migration of the RV lead beyond the cardiac silhouette. Echocardiography revealed no evidence of pericardial effusion or tamponade. Computed tomography revealed that the RV lead was positioned beyond the RV and pericardium and into the anterior chest wall. Procedural lead revision was performed with cardiothoracic surgery backup. The lead was retracted after loosening the active-fixation screw and inserting the stylet. The lead was placed in the RV septum with active fixation. The procedure was completed without complications, and the patient was discharged after 3 days. Subacute lead perforations can present with various symptoms, and some patients may be asymptomatic without pericardial effusion. Altered lead parameters frequently provide the first indication for the diagnosis of cardiac perforation. Transvenous lead revision with surgical backup is an alternative to surgical extraction.

Hydrogen Absorption and Desorption Behavior on Aluminum-Coated Hot-Stamped Boron Steel during Hot Press Forming and Automotive Manufacturing Processes.

Our study mainly focused on diffusible hydrogen in aluminum-silicon-coated hot-stamped boron steel during a hot press forming process and in pre-treatment sequential lines of the automotive manufacturing process using a thermal desorption spectroscopy (TDS) technique. First, in the hot stamping procedure, as the soaking time increased in the heating furnace at a specific dew point when austenitizing, a high concentration of diffusible hydrogen was absorbed into the hot-stamped boron steel. Based on the TDS analysis of hydrogen absorbed from hot stamping, the activation energy value of hydrogen trapping in 1.8 GPa grade steel is lower than that of 1.5 GPa grade steel. This means that diffusible hydrogen can be more easily diffused into defective sites of the microstructure at a higher level of the tensile strength grade. Second, in sequential pre-treatment lines of the automotive manufacturing process, additional hydrogen did not flow into the surface, and an electro-deposition process, including a baking procedure, was effective in removing diffusible hydrogen, which was similar to the residual hydrogen of the as-received state (i.e., initial cold rolled blank). Based on these results, the hydrogen absorption was facilitated during hot press forming, but the hydrogen was sequentially desorbed during automotive sequential lines on aluminum-coated hot-stamped steel parts.

Colorado Water Watch: real-time groundwater monitoring for possible contamination from oil and gas activities.

Currently, only a few states in the USA (e.g., Colorado and Ohio) require mandatory baseline groundwater sampling from nearby groundwater wells prior to drilling a new oil or gas well. Colorado is the first state to regulate groundwater testing before and after drilling, which requires one pre-drilling sample and two additional post-drilling samples within 6-12 months and 5-6 years of drilling. However, the monitoring method is limited to the state's regulatory agency and to ex situ sampling, which offers only a snapshot in time. To overcome the limitations and increase monitoring performance, a new groundwater monitoring system, Colorado Water Watch (CWW), was introduced as a decision-making tool to support the state's regulatory agency and also to provide real-time groundwater quality data to both the industry and the public. The CWW uses simple in situ water quality sensors based on the surrogate sensing technology that employs an event detection system to screen the incoming data in near real-time.

Concurrence of aqueous and gas phase contamination of groundwater in the Wattenberg oil and gas field of northern Colorado.

The potential impact of rapid development of unconventional oil and natural gas resources using hydraulic fracturing and horizontal drilling on regional groundwater quality has received significant attention. Major concerns are methane or oil/gas related hydrocarbon (such as TPHs, BTEX including benzene, toluene, ethybenzene and xylene) leaks into the aquifer due to the failure of casing and/or stray gas migration. Previously, we investigated the relationship between oil and gas activity and dissolved methane concentration in a drinking water aquifer with the major finding being the presence of thermogenic methane contamination, but did not find detectable concentrations of TPHs or BTEX. To understand if aqueous and gas phases from the producing formation were transported concurrently to drinking water aquifers without the presence of oil/gas related hydrocarbons, the ionic composition of three water groups was studied: (1) uncontaminated deep confined aquifer, (2) suspected contaminated groundwater - deep confined aquifer containing thermogenic methane, and (3) produced water from nearby oil and gas wells that would represent aqueous phase contaminants. On the basis of quantitative and spatial analysis, we identified that the "thermogenic methane contaminated" groundwater did not have similarities to produced water in terms of ionic character (e.g. Cl/TDS ratio), but rather to the "uncontaminated" groundwater. The analysis indicates that aquifer wells with demonstrated gas phase contamination have not been contacted by an aqueous phase from oil and gas operations according to the methodology we use in this study and the current groundwater quality data from COGCC. However, the research does not prove conclusively that this the case. The results may provide insight on contamination mechanisms since improperly sealed well casing may result in stray gas but not aqueous phase transport.

Validation of the Korean version of the Connor-Davidson Resilience Scale-2 in firefighters and rescue workers.

OBJECTIVE: Resilience has been considered as a protective factor against stress. Evaluating resilience in firefighters and rescue workers, who are frequently exposed to traumatic events, is important and relevant. This study examined the psychometric properties of the Korean version of the Connor-Davidson Resilience Scale-2 (CD-RISC2). METHODS: Two-hundred twenty-two current professional firefighters and rescue workers were assessed by standardized, semi-structured clinical interviews and self-report questionnaires. Internal consistency, correlation with the CD-RISC, convergent validity, divergent validity, and predictive validity of posttraumatic stress disorder (PTSD) symptom severity were analyzed. RESULTS: The CD-RISC2 demonstrated good internal consistency (α=0.75), item-total correlation (r=0.89-0.90), and convergent and divergent validity. The total score of the CD-RISC2 showed significant correlations with the subtotal of the remaining 23 CD-RISC items (r=0.77, p<0.001) and with the score of each CD-RISC item (r=0.15-0.66, all p<0.05). The magnitude of the relationship between the number of traumatic experiences and PTSD symptom severity was greater in the low resilience group than in the high resilience group (p for interaction=0.002). The likelihood-ratio test confirmed that the model predicting PTSD symptom severity based on the CD-RISC2 total score was not improved by the inclusion of subtotal scores of the remaining 23 CD-RISC items (χ(2)=0.31, p=0.58). CONCLUSIONS: These results suggest that the CD-RISC2 would be a valuable tool in evaluating resilience quickly and efficiently in firefighters and rescue workers.

Total phosphorus input to the Cache la Poudre River in Northern Colorado.

The objectives of this study were to monitor total phosphorus concentrations and loads along the Cache la Poudre River in Northern Colorado as it flows from a pristine area through urban regions and, finally, through mixed land uses. The study attempted to evaluate the sources and influences of total phosphorus under different hydrologic conditions. Nine sampling events were completed from April 2010 to May 2011 to assess the influence of various hydrologic conditions on aqueous and riverbed sediment total phosphorus concentrations. Total phosphorus concentrations and loads exceeded the in-stream limits proposed by the Colorado Department of Public Health and Environment in all observed hydrologic conditions, and nonpoint sources were significant in high-flow conditions. Reducing nutrients only at water resource recovery facilities (WRRFs) could not achieve the in-stream limits without substantial reduction of non-point-source loads. The study exposed a need for flexibility in WRRF discharge limits based on the overall total phosphorus load in the river from other sources.

Yukmijihwang-tang for the treatment of xerostomia in the elderly: study protocol for a randomized, double-blind, placebo-controlled, two-center trial.

BACKGROUND: Xerostomia, a subjective sense of dry mouth, is not generally regarded a disease despite its high prevalence among the elderly, and therefore continues to impair affected patients' quality of life. In traditional Korean medicine, 'Yin-Deficiency' has been implicated in the pathogenesis of xerostomia among the elderly. Yukmijihwang-tang is a famous herbal prescription used to relieve 'Yin-Deficiency', and reportedly has antioxidant effects; therefore, it is postulated that Yukmijihwang-tang can be used to treat xerostomia in the elderly. However, to our knowledge, no clinical trial has been conducted on the effects of Yukmijihwang-tang on xerostomia. Thus, we designed a randomized clinical trial to investigate the effects and safety of Yukmijihwang-tang on xerostomia in the elderly. In addition, we will clarify the aforementioned assumption that 'Yin-Deficiency' is the major cause of xerostomia in the elderly by identifying a correlation between xerostomia and 'Yin-Deficiency'. METHODS/DESIGN: This randomized, double-blind, placebo-controlled trial will be carried out at two centers: Kyung Hee University Korean Medicine Hospital and Kyung Hee University Hospital at Gangdong. We will recruit 96 subjects aged 60-80 years who have experienced xerostomia for 3 months prior to participation. Subjects who present with score >40 on the visual analogue scale for xerostomia and unstimulated salivary flow rate under 0.3mL/min will be included and the randomization will be carried out by an independent statistician by using a random number creation program. The subjects and all researchers except the statistician will be blinded to the group assignment. Yukmijihwang-tang or placebo will be administered to each group for 8 weeks. The primary outcome is change in the scores for the visual analogue scale for xerostomia and the dry mouth symptom questionnaire from 0 to 8 weeks. DISCUSSION: It will be assessed whether Yukmijihwang-tang can be used as a new herbal treatment for xerostomia in the elderly by demonstrating its therapeutic effects in a well-designed clinical trial. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01579877.

Relative phosphorus load inputs from wastewater treatment plants in a northern colorado watershed.

Excess nutrients are among the leading sources of water quality impairment in the Unites States, and the USEPA has been working with state regulatory agencies to develop nutrient criteria for wastewater treatment plants (WWTPs). The Colorado Department of Public Health and Environment is scheduled to establish nutrient regulations in 2013, and stream total P (TP) concentration standards of 0.16 mg L in warm water and 0.11 mg L in cold water have been proposed for the rivers in the state. The objectives of this study were to monitor TP concentrations and loads along the Cache La Poudre River as it flows from the pristine upstream area through urban regions and finally through a mixture of agricultural and urban land uses. The study attempts to evaluate the sources and influences of TP under different hydrologic conditions. Twelve sampling events were completed from April 2010 to August 2011 to assess the influence of various flow and precipitation conditions on aqueous TP concentrations. During midrange flows and dry conditions, WWTPs were the major sources of TP, but other sources were more significant under high-flow and wet conditions according to a load analysis. The analysis indicates that reducing the TP load from WWTPs will only marginally affect the TP load in the river, and therefore it appears that other sources (e.g., stormwater and agricultural runoff) need to be addressed before the aquatic life-based stream standard can be achieved.

Will stringent total nitrogen wastewater treatment plant discharge regulations achieve stream water quality goals?

The Colorado Department of Public Health and Environment (CDPHE) proposed the in-stream numeric nutrient criteria as 2 mg TN per L and 0.16 mg TP per L for warm surface waters and 0.40 mg TN per L and 0.11 mg TP per L for cold surface waters. Consequently the department presented the nutrient limits for the municipal wastewater treatment plants (WWTPs) as annual averages of 0.7 mg TP per L and 5.7 mg TIN per L and quarterly averages of 1.0 mg TP per L and 9.0 mg TIN per L. Implementing stringent nutrient reduction at point sources is unlikely to result in improvements to the environment without non-point source controls. In this study, total nitrogen (TN) load inputs from known point source, WWTPs, and other non-point sources at six sub-basins of the Cache La Poudre (CLP) River Basin were estimated and compared under various hydrologic conditions. Significant loading exceedance from the proposed limits was observed during lower flow conditions and other sources dominated during events when the exceedance was observed except for one point. The point receives direct TN inputs from a WWTP which has the highest TN concentration in its effluent among all WWTPs in the study area; however, TN loads entered the point from other sources were significant during higher flow conditions. TN loads in the CLP River were simulated to determine whether the loads meet the proposed in-stream limits in a case in which all WWTPs comply with the proposed regulations for WWTPs. From this study, it was observed that reducing TN concentrations only at WWTPs merely impacts total TN loads in the river.

Synthesis and electroluminescence properties of novel deep blue emitting 6,12-dihydro-diindeno[1,2-b;1',2'-e]pyrazine derivatives.

Deep blue emitting materials with a new core structure containing indenopyrazine have been synthesized; a non-doped device using one of these materials as a blue emitter was found to exhibit high external quantumn efficiency of 4.6% and excellent color purity of (0.154, 0.078) as well as narrow emission band of 47 nm FWHM.