Influence of implant location on the clinical outcomes of implant abutments: a systematic review and meta-analysis

PubMed Central

ElHoussiney, Amr G; Zhang, He; Song, Jinlin; Ji, Ping; Wang, Lu; Yang, Sheng

2018-01-01

Purpose To compare the failure events and incidence of complications of different abutment materials in anterior and posterior regions. Failure was defined as complete loss of the abutment requiring replacement by a new abutment. Materials and methods Electronic searches using PubMed/Medline and Google Scholar complemented with manual searches were performed with specific search terms. Searches were restricted to publications in English between January 2006 and March 2016. Results A total of 863 and 1,264 implants were inserted in the anterior and posterior regions, respectively, in a total of 1,529 patients. No titanium abutments failed in anterior or posterior regions. On the other hand, 1.6% of zirconia abutments failed in the anterior region and 1.5% failed in the posterior region. Technical complications occurred mostly in the posterior region and mostly involved zirconia abutment. Meta-analysis was possible only for zirconia-abutment failure, due to considerable heterogeneity of studies and outcome variables. No significant difference in failure rate was found between anterior and posterior zirconia abutments (risk ratio 1.53, 95% CI 0.49–4.77; P=0.47). Conclusion This systematic review and meta-analysis showed similar outcomes of different abutment materials when used in anterior and posterior regions in terms of failure events and biological and aesthetic complications. The only significant finding was the increased incidence of technical complications in the posterior region, mostly involving zirconia abutments. Abutment-screw loosening was the most common technical complication. PMID:29520162

Experience in cochlear reimplantation. Descriptive study of a 20-year period.

PubMed

Gutiérrez-Salazar, Andrés; Cop, Constanze; Osorio-Acosta, Ángel; Borkoski-Barreiro, Silvia; Falcón-González, Juan C; Ramos-Macías, Ángel

2015-01-01

The cochlear implant is a surgical procedure that has increased substantially, because the paediatric population is diagnosed and implanted early and because there are increased potential indications. This device has the inherent risk of failure in performance, as dies any active medical device, which is the most common cause of implant removal. Our goal was to understand what the causes that produced removal in our series were, and confirm if these conformed to reality as reviewed in the literature. This was a retrospective, descriptive, observational study of 859 cochlear implant surgeries carried out between October 1991 and May 2011. The causes of implant removal were classified according to the European Consensus Statement on Cochlear Implant Failures and Explantations. The reimplantation rate was 6.16% (n=51). The most common reason for removal was technical device failure (45.5%), followed by infection/rejection (23.6%) and upgrade (12.7%). Less common causes: there were 3 cases (5.6%) of electrode misplacement, 2 cases (3.6%) of labyrinthine ossification, 2 (3.6%) as a result of head trauma, 2 (3.6%) from need for nuclear magnetic resonance imaging and 1 case (1.8%) from psychiatric illness. Cochlear reimplantation is a safe procedure, with a low complication rate. In our centre, it reaches an overall rate of 6.16%. Technical device failure remains the most common cause of this procedure, although there is a significant percentage of reimplantation for device update. Copyright © 2014 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Newly Designed Y-configured Single-Catheter Stenting for the Treatment of Hilar-Type Nonanastomotic Biliary Strictures After Orthotopic Liver Transplantation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Changming; Li Xuan, E-mail: lixuanbysy@163.com; Song Shibing

2012-02-15

Purpose: This study was designed to introduce our novel technique of percutaneous single catheter placement into the hilar bile ducts strictures while fulfilling the purpose of bilateral biliary drainage and stenting. We investigated the efficacy and safety of the technique for the treatment of hilar nonanastomotic biliary strictures. Methods: Ten patients who were post-orthotopic liver transplantation between July 2000 and July 2010 were enrolled in this study. Percutaneous Y-configured single-catheter stenting for bilateral bile ducts combined with balloon dilation was designed as the main treatment approach. Technical success rate, clinical indicators, complications, and recurrent rate were analyzed. Results: Technical successmore » rate was 100%. Nine of the ten patients had biochemical normalization, cholangiographic improvement, and clinical symptoms relief. None of them experienced recurrence in a median follow-up of 26 months after completion of therapy and removal of all catheters. Complications were minor and limited to two patients. The one treatment failure underwent a second liver transplantation but died of multiple system organ failure. Conclusions: Percutaneous transhepatic Y-configured single-catheter stenting into the hilar bile ducts is technically feasible. The preliminary trial of this technique combined with traditional PTCD or choledochoscopy for the treatment of hilar biliary strictures after orthotopic liver transplantation appeared to be effective and safe. Yet, further investigation is needed.« less

Improved technical success and radiation safety of adrenal vein sampling using rapid, semi-quantitative point-of-care cortisol measurement.

PubMed

Page, Michael M; Taranto, Mario; Ramsay, Duncan; van Schie, Greg; Glendenning, Paul; Gillett, Melissa J; Vasikaran, Samuel D

2018-01-01

Objective Primary aldosteronism is a curable cause of hypertension which can be treated surgically or medically depending on the findings of adrenal vein sampling studies. Adrenal vein sampling studies are technically demanding with a high failure rate in many centres. The use of intraprocedural cortisol measurement could improve the success rates of adrenal vein sampling but may be impracticable due to cost and effects on procedural duration. Design Retrospective review of the results of adrenal vein sampling procedures since commencement of point-of-care cortisol measurement using a novel single-use semi-quantitative measuring device for cortisol, the adrenal vein sampling Accuracy Kit. Success rate and complications of adrenal vein sampling procedures before and after use of the adrenal vein sampling Accuracy Kit. Routine use of the adrenal vein sampling Accuracy Kit device for intraprocedural measurement of cortisol commenced in 2016. Results Technical success rate of adrenal vein sampling increased from 63% of 99 procedures to 90% of 48 procedures ( P = 0.0007) after implementation of the adrenal vein sampling Accuracy Kit. Failure of right adrenal vein cannulation was the main reason for an unsuccessful study. Radiation dose decreased from 34.2 Gy.cm 2 (interquartile range, 15.8-85.9) to 15.7 Gy.cm 2 (6.9-47.3) ( P = 0.009). No complications were noted, and implementation costs were minimal. Conclusions Point-of-care cortisol measurement during adrenal vein sampling improved cannulation success rates and reduced radiation exposure. The use of the adrenal vein sampling Accuracy Kit is now standard practice at our centre.

Study of Cavitation and Failure Mechanisms of a Superplastic 5083 Aluminum Alloy

DTIC Science & Technology

2003-09-01

Failure Mechanisms of a Superplastic 5083 Aluminum Alloy 6. AUTHOR( S ) Boydon, Juanito F. 5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME( S ) AND...NAME( S ) AND ADDRESS(ES) General Motors Corp., Research and Development Center, Warren, MI (Dr. Paul E. Krajewski, Technical Program...of 973931(A3), deformed gauge area 1- region 1. Sample was pulled under uniaxial tension at 450 °C at a strain rate of 3x10-4 s -1 and elongated to

Salpingitis Isthmica Nodosa: Technical Success and Outcome of Fluoroscopic Transcervical Fallopian Tube Recanalization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Houston, J. Graeme; Machan, Lindsay S.

1998-01-15

Purpose: To evaluate the technical success and outcome of fallopian tube recanalization (FTR) in salpingitis isthmica nodosa (SIN). Methods: SIN is a well-recognized pathological condition affecting the proximal fallopian tube and is associated with infertility and ectopic pregnancy. We reviewed the presentations, films, and case records of all patients attending for FTR for infertility from 1990 to 1994. Technical success and total, intrauterine, and ectopic pregnancy rates at follow-up were determined. Results: SIN was observed in 22 of 349 (6%) patients. FTR was attempted in 34 tubes in these 22 patients. Technical success was achieved in 23 of 34 (68%)more » tubes affected by SIN. In 5 of the 11 failed recanalizations, failure was due to distal obstruction. At least one tube was patent on selective postprocedural salpingography in 17 of 22 (77%) patients. There were no recorded perforations or complications. At follow-up (mean 14 months), total, intrauterine, and ectopic pregnancy rates were 23%, 18%, and 4.5%, respectively. Conclusion: FTR in SIN is technically successful and, compared with previously reported results in unselected infertility patients, is associated with only a slightly less favorable intrauterine pregnancy rate and a comparable ectopic pregnancy rate. The findings of SIN at FTR should not discourage attempted fluoroscopic transcervical recanalization.« less

Use of Self-Expanding Stents for the Treatment of Vertebral Artery Ostial Stenosis: a Single Center Experience

PubMed Central

Chung, Sun Young; Choi, Jin Woo; Choi, Byung Se; In, Hyun Sin; Kim, Sun Mi; Choi, Choong Gon; Kim, Sang Joon; Suh, Dae Chul

2010-01-01

Objective To evaluate our early experience using self-expanding stents to treat atherosclerotic vertebral artery ostial stenosis (VAOS), with respect to technical feasibility and clinical and imaging follow-up results. Materials and Methods A total of 20 lesions in 20 patients underwent stenting of the VAOS using a self-expanding stent (Precise RX; Cordis Neurovascular, Miami Lakes, FL). Two patients were asymptomatic. We analyzed the technical success rate, causes of technical failure, occurrence of any vascular or neurological event, and the occurrence of any neurological abnormality or in-stent restenosis (ISR) seen on follow-up. The imaging follow-up was performed with Doppler ultrasound (DUS) as a primary screening modality. Results One instance of technical failure was caused by failure of the guidewire passage. The stent diameter was 5 mm, and post-stenting balloon dilatations were necessary in all cases. Stent misplacement requiring placement of an additional stent occurred in four cases. Following a 14.8 month average clinical follow-up time, two patients showed anterior circulation ischemia, which was not attributed to the VAOS we treated. Following a 13.7 month average DUS follow-up, five patients showed a mild degree of diffuse or focal intimal thickening in the stent lumen; however, none of the stenosis showed luminal loss of more than 50% and no stent fracture was noted. Conclusion The use of self-expanding stents for treating VAOS was technically feasible and helped to improve artery patency during our limited follow-up interval. PMID:20191062

Trends and problems in development of the power plants electrical part

NASA Astrophysics Data System (ADS)

Gusev, Yu. P.

2015-03-01

The article discusses some problems relating to development of the electrical part of modern nuclear and thermal power plants, which are stemming from the use of new process and electrical equipment, such as gas turbine units, power converters, and intellectual microprocessor devices in relay protection and automated control systems. It is pointed out that the failure rates of electrical equipment at Russian and foreign power plants tend to increase. The ongoing power plant technical refitting and innovative development processes generate the need to significantly widen the scope of research works on the electrical part of power plants and rendering scientific support to works on putting in use innovative equipment. It is indicated that one of main factors causing the growth of electrical equipment failures is that some of components of this equipment have insufficiently compatible dynamic characteristics. This, in turn may be due to lack or obsolescence of regulatory documents specifying the requirements for design solutions and operation of electric power equipment that incorporates electronic and microprocessor control and protection devices. It is proposed to restore the system of developing new and updating existing departmental regulatory technical documents that existed in the 1970s, one of the fundamental principles of which was placing long-term responsibility on higher schools and leading design institutions for rendering scientific-technical support to innovative development of components and systems forming the electrical part of power plants. This will make it possible to achieve lower failure rates of electrical equipment and to steadily improve the competitiveness of the Russian electric power industry and energy efficiency of generating companies.

The Aortic Bifurcation Angle as a Factor in Application of the Outback for Femoropopliteal Lesions in Ipsilateral Versus Contralateral Approaches.

PubMed

Raskin, Daniel; Khaitovich, Boris; Balan, Shmuel; Silverberg, Daniel; Halak, Moshe; Rimon, Uri

2018-01-01

To assess the technical success of the Outback reentry device in contralateral versus ipsilateral approaches for femoropopliteal arterial occlusion. A retrospective review of patients treated for critical limb ischemia (CLI) using the Outback between January 2013 and July 2016 was performed. Age, gender, length and site of the occlusion, approach site, aortic bifurcation angle, and reentry site were recorded. Calcification score was assigned at both aortic bifurcation and reentry site. Technical success was assessed. During the study period, a total of 1300 endovascular procedures were performed on 489 patients for CLI. The Outback was applied on 50 femoropopliteal chronic total occlusions. Thirty-nine contralateral and 11 ipsilateral antegrade femoral were accessed. The device was used successfully in 41 patients (82%). There were nine failures, all in the contralateral approach group. Six due to inability to deliver the device due to acute aortic bifurcation angle and three due to failure to achieve luminal reentry. Procedural success was significantly affected by the aortic bifurcation angle (p = 0.013). The Outback has high technical success rates in treatment of femoropopliteal occlusion, when applied from either an ipsi- or contralateral approach. When applied in contralateral access, acute aortic bifurcation angle predicts procedural failure.

Predicting the failure of retrograde ureteral stent insertion for managing malignant ureteral obstruction in outpatients

PubMed Central

WANG, JIN-YOU; ZHANG, HAI-LIANG; ZHU, YAO; QIN, XIAO-JIAN; DAI, BO; YE, DING-WEI

2016-01-01

Malignant ureteral obstruction (MUO) is an unpropitious sign that is commonly observed in patients with advanced incurable cancer. The present study aimed to evaluate predictive factors for the failure of retrograde ureteral stent insertion in the management of MUO in outpatients. A total of 164 patients with MUO were retrospectively assessed in this study. Clinical factors, including age, gender, type of malignancy, level of obstruction, cause of obstruction, pre-operative creatinine level, degree of hydronephrosis, condition of the contralateral ureter, prior radiotherapy, Eastern Cooperative Oncology Group performance status (ECOG PS), bladder wall invasion and technical failure, were recorded for each case. Univariate and multivariate logistic regression analyses were used to investigate the risk factors for predicting the failure of retrograde ureteral stent insertion. In total, 38 out of 164 patients experienced bilateral obstruction, therefore, a total of 202 ureteral units were available for data analysis. The rate of insertion failure in MUO was 34.65%. Multivariate analyses identified ECOG PS, degree of hydronephrosis and bladder wall invasion as independent predictors for insertion failure. Overall, the present study found that rate of retrograde ureteral stent insertion failure is high in outpatients with MUO, and that ECOG PS, degree of hydronephrosis and bladder invasion are potential independent predictors of insertion failure. PMID:26870299

Push versus pull gastrostomy in cancer patients: A single center retrospective analysis of complications and technical success rates.

PubMed

Currie, B M; Getrajdman, G I; Covey, A M; Alago, W; Erinjeri, J P; Maybody, M; Boas, F E

2018-04-28

To compare the technical success and complication rates of push versus pull gastrostomy tubes in cancer patients, and to examine their dependence on operator experience. A retrospective review was performed of 304 cancer patients (170 men, 134 women; mean age 60.3±12.6 [SD], range: 19-102 years) referred for primary gastrostomy tube placement, 88 (29%) of whom had a previously unsuccessful attempt at percutaneous endoscopic gastrostomy (PEG) placement. Analyzed variables included method of insertion (push versus pull), indication for gastrostomy, technical success, operator experience, and procedure-related complications within 30 days of placement. Gastrostomy tubes were placed for feeding in 189 patients and palliative decompression in 115 patients. Technical success was 91%: 78% after endoscopy had previously been unsuccessful and 97% when excluding failures associated with prior endoscopy. In the first 30 days, there were 29 minor complications (17.2%) associated with push gastrostomies, and only 8 minor complications (7.5%) with pull gastrostomies (P<0.05). There was no significant difference in major complications (push gastrostomy 5.3%, pull gastrostomy 5.6%). For decompressive gastrostomy tubes, the pull technique resulted in lower rates of both minor and major complications. There was no difference in complications or technical success rates for more versus less experienced operators. Pull gastrostomy tube placement had a lower rate of complications than push gastrostomy tube placement, especially when the indication was decompression. The technical success rate was high, even after a failed attempt at endoscopic placement. Both the rates of success and complications were independent of operator experience. Copyright © 2018 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Abstract of Capstone

ERIC Educational Resources Information Center

Pack, Della F.

2013-01-01

At the end of the Fall 2011 semester at Big Sandy Community and Technical College (BSCTC) a comparison of grade patterns in multiple CIS 100-Introduction to Computers courses was analyzed. This analysis found online courses returned a higher failure rate than those taught in a classroom setting. Why was there a difference? Is the platform of…

Effect of an Interactive Component on Students' Conceptual Understanding of Hypothesis Testing

ERIC Educational Resources Information Center

Inkpen, Sarah Anne

2016-01-01

The Premier Technical College of Qatar (PTC-Q) has seen high failure rates among students taking a college statistics course. The students are English as a foreign language (EFL) learners in business studies and health sciences. Course delivery has involved conventional content/ curriculum-centered instruction with minimal to no interactive…

Obesity and Risk of Biochemical Failure for Patients Receiving Salvage Radiotherapy After Prostatectomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, Christopher R.; Spiotto, Michael T.; Kapp, Daniel S.

Purpose: Obesity has been proposed as an independent risk factor for patients undergoing surgery or radiotherapy (RT) for prostate cancer. Using body mass index (BMI) as a measure of obesity, we tested its role as a risk factor for patients receiving salvage RT after prostatectomy. Methods and Materials: Rates of subsequent biochemical relapse were examined in 90 patients who underwent salvage RT between 1984 and 2004 for biochemical failure after radical prostatectomy. Median follow-up was 3.7 years. The BMI was tested as a continuous and categorical variable (stratified as <25, 25-<30, and {>=}30 kg/m{sup 2}). Univariate and multivariate proportional hazardsmore » regression analyses were performed for clinical, pathologic, and treatment factors associated with time to relapse after salvage RT. Results: There were 40 biochemical failures after salvage RT with a median time to failure of 1.2 years. The BMI was not associated with adverse clinical, pathologic, or treatment factors. On multivariate analysis, obesity was independently significant (hazard ratio [HR], 1.2; p = 0.01), along with RT dose (HR, 0.7; p = 0.003) and pre-RT prostate-specific antigen level (HR, 1.2; p = 0.0003). Conclusions: This study is weakly suggestive that obesity may be a risk factor for salvage RT patients. Whether this results from greater biologic aggressiveness or technical inadequacies cannot be answered by this study. Given the very high failure rate observed for severely obese patients, we propose that technical difficulties with RT are at play. This hypothesis is supported by the RT literature and could be prospectively investigated. Techniques that optimize targeting, especially in obese patients, perhaps seem warranted at this time.« less

Importance of technical preparation of intraarterial shunts to prevent iatrogenic arterial injury during urgent procedures.

PubMed

Awad, Nadia; Choudry, Rashad; Durinka, Joel; Prabhu, Aparna; Dissin, Jonathan

2013-02-01

Although intraarterial shunting during carotid endarterectomy is a well-defined practice, its use remains controversial. Complication rates associated with shunt placement remain low, but may be underreported. When complications secondary to routine intraarterial shunting occur, they can cause significant morbidity or even mortality, emphasizing the importance of meticulous technique to prevent adverse outcomes. We report a case of internal carotid artery dissection and pseuedoaneurysm due to the technical failure of a safety device of an intraarterial shunt used during carotid endarterectomy.

Renewable energy for rural electrification in developing countries

NASA Astrophysics Data System (ADS)

Morgenstern, Joy

The environmental destruction caused by traditional methods of generating electricity and the environmental benefits of using renewable energy technologies are well-known. In additional to the environmental benefits, small, decentralized renewable energy systems are often the most economical way to electrify the rural areas of developing countries, where most of the world's unelectrified population lives. However, diffusion of these systems is proceeding very slowly and many of these projects have failed. This dissertation examines the hypothesis that an important determinant of the success of these projects is the extent to which they are compatible with the social and cultural attributes of the communities in which they are located. The hypothesis was examined by evaluating sixteen solar, wind and hybrid electrification projects in Mexico, using a procedure which rates projects according to criteria which reflect technical, economic and financial, environmental, and sociocultural factors deemed necessary to achieve success. Reasons for poor ratings within these criteria were then used to determine six preconditions for project success. The evaluation indicates that most of the wind and hybrid projects visited had low success ratings because of technical problems. The solar home system projects experienced few technical problems, yet many were unsuccessful. Most of the projects were unsustainable due to lack of financial resources, insufficient financial mechanisms, poor user training. In none of the communities were the projects economically viable, nor were they compatible with the needs of the users. The future success of even the most successful projects seen is doubtful because of the lack of provision for any maintenance by trained technicians and the scarcity of financial resources. A direct relationship between failure at the sociocultural criteria and overall project failure was not found. In most cases, failure at particular criteria could be attributed to the project developers' inability to fulfill social and cultural aspects of the preconditions for success, thus establishing an indirect but causal relationship between sociocultural attributes of communities and project success.

Numerical simulation of deformation and failure processes of a complex technical object under impact loading

NASA Astrophysics Data System (ADS)

Kraus, E. I.; Shabalin, I. I.; Shabalin, T. I.

2018-04-01

The main points of development of numerical tools for simulation of deformation and failure of complex technical objects under nonstationary conditions of extreme loading are presented. The possibility of extending the dynamic method for construction of difference grids to the 3D case is shown. A 3D realization of discrete-continuum approach to the deformation and failure of complex technical objects is carried out. The efficiency of the existing software package for 3D modelling is shown.

Revision surgery for failed thermal capsulorrhaphy.

PubMed

Park, Hyung Bin; Yokota, Atsushi; Gill, Harpreet S; El Rassi, George; McFarland, Edward G

2005-09-01

With the failure of thermal capsulorrhaphy for shoulder instability, there have been concerns with capsular thinning and capsular necrosis affecting revision surgery. To report the findings at revision surgery for failed thermal capsulorrhaphy and to evaluate the technical effects on subsequent revision capsular plication. Case series; Level of evidence, 4. Fourteen patients underwent arthroscopic evaluation and open reconstruction for a failed thermal capsulorrhaphy. The cause of the failure, the quality of the capsule, and the ability to suture the capsule were recorded. The patients were evaluated at follow-up for failure, which was defined as recurrent subluxations or dislocations. The origin of the instability was traumatic (n = 6) or atraumatic (n = 8). At revision surgery in the traumatic group, 4 patients sustained failure of the Bankart repair with capsular laxity, and the others experienced capsular laxity alone. In the atraumatic group, all patients experienced capsular laxity as the cause of failure. Of the 14 patients, the capsule quality was judged to be thin in 5 patients and ablated in 1 patient. A glenoid-based capsular shift could be accomplished in all 14 patients. At follow-up (mean, 35.4 months; range, 22 to 48 months), 1 patient underwent revision surgery and 1 patient had a subluxation, resulting in a failure rate of 14%. Recurrent capsular laxity after failed thermal capsular shrinkage is common and frequently associated with capsular thinning. In most instances, the capsule quality does not appear to technically affect the revision procedure.

Understanding the Role of Culture and Communication in Implementing Planned Organizational Change: The Case of Compstat in Police Organizations

ERIC Educational Resources Information Center

Yuksel, Yusuf

2013-01-01

Despite the popularity of planned change efforts, the failure rates of implementation are as high as 50 to 70 percent (Lewis & Seibold, 1998). While these efforts are affected by technical issues, the organizations' approach to change, structure, technological capabilities, and organizational culture and communication practices are…

Preoperative short hookwire placement for small pulmonary lesions: evaluation of technical success and risk factors for initial placement failure.

PubMed

Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Masaoka, Yoshihisa; Tanaka, Takashi; Sato, Takuya; Gobara, Hideo; Toyooka, Shinichi; Kanazawa, Susumu

2018-05-01

To retrospectively evaluate the technical success of computed tomography fluoroscopy-guided short hookwire placement before video-assisted thoracoscopic surgery and to identify the risk factors for initial placement failure. In total, 401 short hookwire placements for 401 lesions (mean diameter 9.3 mm) were reviewed. Technical success was defined as correct positioning of the hookwire. Possible risk factors for initial placement failure (i.e., requirement for placement of an additional hookwire or to abort the attempt) were evaluated using logistic regression analysis for all procedures, and for procedures performed via the conventional route separately. Of the 401 initial placements, 383 were successful and 18 failed. Short hookwires were finally placed for 399 of 401 lesions (99.5%). Univariate logistic regression analyses revealed that in all 401 procedures only the transfissural approach was a significant independent predictor of initial placement failure (odds ratio, OR, 15.326; 95% confidence interval, CI, 5.429-43.267; p < 0.001) and for the 374 procedures performed via the conventional route only lesion size was a significant independent predictor of failure (OR 0.793, 95% CI 0.631-0.996; p = 0.046). The technical success of preoperative short hookwire placement was extremely high. The transfissural approach was a predictor initial placement failure for all procedures and small lesion size was a predictor of initial placement failure for procedures performed via the conventional route. • Technical success of preoperative short hookwire placement was extremely high. • The transfissural approach was a significant independent predictor of initial placement failure for all procedures. • Small lesion size was a significant independent predictor of initial placement failure for procedures performed via the conventional route.

Monitoring the quality of total hip replacement in a tertiary care department using a cumulative summation statistical method (CUSUM).

PubMed

Biau, D J; Meziane, M; Bhumbra, R S; Dumaine, V; Babinet, A; Anract, P

2011-09-01

The purpose of this study was to define immediate post-operative 'quality' in total hip replacements and to study prospectively the occurrence of failure based on these definitions of quality. The evaluation and assessment of failure were based on ten radiological and clinical criteria. The cumulative summation (CUSUM) test was used to study 200 procedures over a one-year period. Technical criteria defined failure in 17 cases (8.5%), those related to the femoral component in nine (4.5%), the acetabular component in 32 (16%) and those relating to discharge from hospital in five (2.5%). Overall, the procedure was considered to have failed in 57 of the 200 total hip replacements (28.5%). The use of a new design of acetabular component was associated with more failures. For the CUSUM test, the level of adequate performance was set at a rate of failure of 20% and the level of inadequate performance set at a failure rate of 40%; no alarm was raised by the test, indicating that there was no evidence of inadequate performance. The use of a continuous monitoring statistical method is useful to ensure that the quality of total hip replacement is maintained, especially as newer implants are introduced.

Clinical outcome of double crown-retained implant overdentures with zirconia primary crowns

PubMed Central

Buergers, Ralf; Ziebolz, Dirk; Roediger, Matthias

2015-01-01

PURPOSE This retrospective study aims at the evaluation of implant-supported overdentures (IODs) supported by ceramo-galvanic double crowns (CGDCs: zirconia primary crowns + galvano-formed secondary crown). MATERIALS AND METHODS In a private practice, 14 patients were restored with 18 IODs (mandible: 11, maxilla: 7) retained by CGDCs on 4 - 8 implants and annually evaluated for technical and/or biological failures/complications. RESULTS One of the 86 inserted implants failed during the healing period (cumulative survival rate (CSR) implants: 98.8%). During the prosthetic functional period (mean: 5.9 ± 2.2 years), 1 implant demonstrated an abutment fracture (CSR-abutments: 98.2%), and one case of peri-implantitis was detected. All IODs remained in function (CSR-denture: 100%). A total of 15 technical complications required interventions to maintain function (technical complication rate: 0.178 treatments/patients/year). CONCLUSION Considering the small sample size, the use of CGDCs for the attachment of IODs is possible without an increased risk of technical complications. However, for a final evaluation, results from a larger cohort are required. PMID:26330981

45 CFR 305.62 - Disregard of a failure which is of a technical nature.

Code of Federal Regulations, 2014 CFR

2014-10-01

... nature. 305.62 Section 305.62 Public Welfare Regulations Relating to Public Welfare OFFICE OF CHILD... PENALTIES § 305.62 Disregard of a failure which is of a technical nature. A State subject to a penalty under... the noncompliance with one or more of the IV-D requirements, is of a technical nature which does not...

45 CFR 305.62 - Disregard of a failure which is of a technical nature.

Code of Federal Regulations, 2011 CFR

2011-10-01

... nature. 305.62 Section 305.62 Public Welfare Regulations Relating to Public Welfare OFFICE OF CHILD... PENALTIES § 305.62 Disregard of a failure which is of a technical nature. A State subject to a penalty under... the noncompliance with one or more of the IV-D requirements, is of a technical nature which does not...

45 CFR 305.62 - Disregard of a failure which is of a technical nature.

Code of Federal Regulations, 2013 CFR

2013-10-01

... nature. 305.62 Section 305.62 Public Welfare Regulations Relating to Public Welfare OFFICE OF CHILD... PENALTIES § 305.62 Disregard of a failure which is of a technical nature. A State subject to a penalty under... the noncompliance with one or more of the IV-D requirements, is of a technical nature which does not...

45 CFR 305.62 - Disregard of a failure which is of a technical nature.

Code of Federal Regulations, 2012 CFR

2012-10-01

... nature. 305.62 Section 305.62 Public Welfare Regulations Relating to Public Welfare OFFICE OF CHILD... PENALTIES § 305.62 Disregard of a failure which is of a technical nature. A State subject to a penalty under... the noncompliance with one or more of the IV-D requirements, is of a technical nature which does not...

Nighttime kidney transplantation is associated with less pure technical graft failure.

PubMed

Brunschot, Denise M D Özdemir-van; Hoitsma, Andries J; van der Jagt, Michel F P; d'Ancona, Frank C; Donders, Rogier A R T; van Laarhoven, Cees J H M; Hilbrands, Luuk B; Warlé, Michiel C

2016-07-01

To minimize cold ischemia time, transplantations with kidneys from deceased donors are frequently performed during the night. However, sleep deprivation of those who perform the transplantation may have adverse effects on cognitive and psychomotor performance and may cause reduced cognitive flexibility. We hypothesize that renal transplantations performed during the night are associated with an increased incidence of pure technical graft failure. A retrospective analysis of data of the Dutch Organ Transplant Registry concerning all transplants from deceased donors between 2000 and 2013 was performed. Nighttime surgery was defined as the start of the procedure between 8 p.m. and 8 a.m. The primary outcome measure was technical graft failure, defined as graft loss within 10 days after surgery without signs of (hyper)acute rejection. Of 4.519 renal transplantations in adult recipients, 1.480 were performed during the night. The incidence of pure technical graft failure was 1.0 % for procedures started during the night versus 2.6 % for daytime surgery (p = .001). In a multivariable model, correcting for relevant donor, recipient and graft factors, daytime surgery was an independent predictor of pure technical graft failure (p < .001). Limitation of this study is mainly to its retrospective design, and the influence of some relevant variables, such as the experience level of the surgeon, could not be assessed. We conclude that nighttime surgery is associated with less pure technical graft failures. Further research is required to explore factors that may positively influence the performance of the surgical team during the night.

Clinical risk factors related to failures with zirconia-based restorations: an up to 9-year retrospective study.

PubMed

Koenig, Vinciane; Vanheusden, Alain J; Le Goff, Stéphane O; Mainjot, Amélie K

2013-12-01

The first objective of this study was to retrospectively evaluate zirconia-based restorations (ZBR). The second was to correlate failures with clinical parameters and to identify and to analyse chipping failures using fractographic analysis. 147 ZBR (tooth- and implant-supported crowns and fixed partial dentures (FPDs)) were evaluated after a mean observation period of 41.5 ± 31.8 months. Accessorily, zirconia implant abutments (n=46) were also observed. The technical (USPHS criteria) and the biological outcomes of the ZBR were evaluated. Occlusal risk factors were examined: occlusal relationships, parafunctional habits, and the presence of occlusal nightguard. SEM fractographic analysis was performed using the intra-oral replica technique. The survival rate of crowns and FPDs was 93.2%, the success rate was 81.63% and the 9-year Kaplan-Meier estimated success rate was 52.66%. The chipping rate was 15% and the framework fracture rate was 2.7%. Most fractographic analyses revealed that veneer fractures originated from occlusal surface roughness. Several parameters were shown to significantly influence veneer fracture: the absence of occlusal nightguard (p=0.0048), the presence of a ceramic restoration as an antagonist (p=0.013), the presence of parafunctional activity (p=0.018), and the presence of implants as support (p=0.026). The implant abutments success rate was 100%. The results of the present study confirm that chipping is the first cause of ZBR failure. They also underline the importance of clinical parameters in regards to the explanation of this complex problem. This issue should be considered in future prospective clinical studies. Practitioners can reduce chipping failures by taking into account several risk parameters, such as the presence of a ceramic restoration as an antagonist, the presence of parafunctional activity and the presence of implants as support. The use of an occlusal nightguard can also decrease failure rate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Risk Factors for Long-Term Mortality and Amputation after Open and Endovascular Treatment of Acute Limb Ischemia.

PubMed

Genovese, Elizabeth A; Chaer, Rabih A; Taha, Ashraf G; Marone, Luke K; Avgerinos, Efthymios; Makaroun, Michel S; Baril, Donald T

2016-01-01

Acute limb ischemia (ALI) is a highly morbid and fatal vascular emergency with little known about contemporary, long-term patient outcomes. The goal was to determine predictors of long-term mortality and amputation after open and endovascular treatment of ALI. A retrospective review of ALI patients at a single institution from 2005 to 2011 was performed to determine the impact of revascularization technique on 5-year mortality and amputation. For each main outcome 2 multivariable models were developed; the first adjusted for preoperative clinical presentation and procedure type, the second also adjusted for postoperative adverse events (AEs). A total of 445 limbs in 411 patients were treated for ALI. Interventions included surgical thrombectomy (48%), emergent bypass (18%), and endovascular revascularization (34%). Mean age was 68 ± 15 years, 54% were male, and 23% had cancer. Most patients presented with Rutherford classification IIa (54%) or IIb (39%). The etiology of ALI included embolism (27%), in situ thrombosis (28%), thrombosed bypass grafts (32%), and thrombosed stents (13%). Patients treated with open procedures had significantly more advanced ischemia and higher rates of postoperative respiratory failure, whereas patients undergoing endovascular interventions had higher rates of technical failure. Rates of postprocedural bleeding and cardiac events were similar between both treatments. Excluding Rutherford class III patients (n = 12), overall 5-year mortality was 54% (stratified by treatment, 65% for thrombectomy, 63% for bypass, and 36% for endovascular, P < 0.001); 5-year amputation was 28% (stratified by treatment, 18% for thrombectomy, 27% for bypass, and 17% for endovascular, P = 0.042). Adjusting for comorbidities, patient presentation, AEs, and treatment method, the risk of mortality increased with age (hazard ratio [HR] = 1.04, P < 0.001), female gender (HR = 1.50, P = 0.031), cancer (HR = 2.19, P < 0.001), fasciotomy (HR = 1.69, P = 0.204) in situ thrombosis or embolic etiology (HR = 1.73, P = 0.007), cardiac AEs (HR = 2.25, P < 0.001), respiratory failure (HR = 2.72, P < 0.001), renal failure (HR = 4.70, P < 0.001), and hemorrhagic events (HR = 2.25, P = 0.003). Risk of amputation increased with advanced ischemia (Rutherford IIb compared with IIa, HR = 2.57, P < 0.001), thrombosed bypass etiology (HR = 3.53, P = 0.002), open revascularization (OR; HR = 1.95, P = 0.022), and technical failure of primary intervention (HR = 6.01, P < 0.001). After the treatment of ALI, long-term mortality and amputation rates were greater in patients treated with open techniques; OR patients presented with a higher number of comorbidities and advanced ischemia, while also experiencing a higher rate of major postoperative complications. Overall, mortality rates remained high and were most strongly associated with baseline comorbidities, acuity of presentation, and perioperative AEs, particularly respiratory failure. Comparatively, amputation risk was most highly associated with advanced ischemia, thrombosed bypass, and failure of the initial revascularization procedure. Copyright © 2016 Elsevier Inc. All rights reserved.

Technical success from endovascular aneurysm repair in the post-marketing era: a multicenter prospective trial.

PubMed

Naslund, Thomas C; Becker, Stacey Y

2003-01-01

Evaluation of post-marketing success with the Ancure Endovascular Graft (AEG) was accomplished by review of a multicenter, prospective trial involving 46 centers and 163 patients. A second cohort of patients (n = 350) treated with the AEG under a controlled-use interval prior to the prospective trial was simultaneously evaluated. Technical success in both groups of patients (96.9% and 97.4%, respectively) was similar to what was reported in pre-market clinical trials. Operative implantation complications unique to the AEG included graft limb stenosis/occlusion in 35.6 and 31.4%, contralateral pull wire being caught on hooks in 33.7 and 28%, failure to seal (type I endoleak) in 17.2 and 18.3%, jacket guard being stuck in 12.9 and 11%, contralateral wire being stuck in 6.8 and 7.1%, high jacket retraction force in 16 and 8.5%, and inability to retract jacket in 1.8 and 0.5% of patients involved in the multicenter trial and controlled-use interval, respectively. One of four patients undergoing conversion in the prospective trial had graft misdeployment as a mode of failure. Three were converted for access failure. The 30-day mortality rate in the prospective trial was 3.7%. Interventions to resolve implantation-related events included stenting, guide catheter manipulations, wire exchanges, and delivery catheter disassembly. These interventions were successful in virtually every case. Open surgical procedures were not needed to correct these operative problems. Results from this study demonstrate excellent technical success with the AEG in the post-market era. Interventions to resolve implantation complications, when utilized, are highly successful in facilitating AEG implantation and providing technical success.

Biological and technical complications and failures with fixed partial dentures (FPD) on implants and teeth after four to five years of function.

PubMed

Brägger, U; Aeschlimann, S; Bürgin, W; Hämmerle, C H; Lang, N P

2001-02-01

The aim of this study was to compare the frequency of biological and technical complications with fixed partial dentures (FPDs) on implants, teeth and as mixed tooth-implant supported FPDs over 4 to 5 years of function. All implants belonged to the ITI Dental Implant System. Group I-I (implant FPD) included 33 patients with 40 FPDs, group T-T (tooth FPDs) 40 patients with 58 FPDs, group I-T (mixed tooth-implant FPDs) 15 with 18 FPD. Of the bridge abutments 144 were teeth and 105 were implants. The median number of units replaced by the FPDs was 3 (range 2-14). The mean age of the patients was 55.7 years (range 23-83). Complete failures resulted in the loss of one FPD in each group. Two implants were lost due to fracture secondarily to development of a bone defect. One tooth had a vertical fracture and 1 tooth was lost due to periodontitis. Biological complications (peri-implantitis, PPD > or = 5 mm and BOP+) occurred at 9.6% (10) of the implants. This number was, however, reduced to 5% if the threshold for definition of peri-implantitis was set at PPD > or = 6 mm and BOP+. Biological complications occurred in 11.8% (17) of the abutment teeth (NS compared to implants); 2.8% (4) had secondary caries, 4.9% (7) endodontic problems and 4.1% (6) had periodontitis (PPD > or = 5 mm, BOP+). Ten out of 32 patients with a general health problem indicated a biological complication, whereas 9 out of 53 patients with no general health problem had a biological complication (chi 2: NS). Statistically significantly more technical complications were found in FPDs on implants (chi 2, P < or = 0.05). The technical complications were associated with bruxism. Out of 10 bruxers 6 had a technical complication whereas 13 out of 75 non-bruxers had such a complication (chi 2 < or = 0.01). Extensions were associated with more technical complications (13 out of 35 with extensions versus 9 out of 81 without). In conclusion, favourable clinical conditions were found at tooth and implant abutments after 4-5 years of function. Loss of FPD over 4-5 years occurred at a similar rate with mixed, implant or tooth supported reconstructions. Significantly more porcelain fractures were found in FPDs on implants. Impaired general health status was not significantly associated with more biological failures but bruxism as well as extensions were associated with more technical failures.

New and improved ways to treat hydrocephalus: Pursuit of a smart shunt.

PubMed

Lutz, Barry R; Venkataraman, Pranav; Browd, Samuel R

2013-01-01

The most common treatment for hydrocephalus is placement of a cerebrospinal fluid shunt to supplement or replace lost drainage capacity. Shunts are life-saving devices but are notorious for high failure rates, difficulty of diagnosing failure, and limited control options. Shunt designs have changed little since their introduction in 1950s, and the few changes introduced have had little to no impact on these long-standing problems. For decades, the community has envisioned a "smart shunt" that could provide advanced control, diagnostics, and communication based on implanted sensors, feedback control, and telemetry. The most emphasized contribution of smart shunts is the potential for advanced control algorithms, such as weaning from shunt dependency and personalized control. With sensor-based control comes the opportunity to provide data to the physician on patient condition and shunt function, perhaps even by a smart phone. An often ignored but highly valuable contribution would be designs that correct the high failure rates of existing shunts. Despite the long history and increasing development activity in the past decade, patients are yet to see a commercialized smart shunt. Most smart shunt development focuses on concepts or on isolated technical features, but successful smart shunt designs will be a balance between technical feasibility, economic viability, and acceptable regulatory risk. Here, we present the status of this effort and a framework for understanding the challenges and opportunities that will guide introduction of smart shunts into patient care.

New and improved ways to treat hydrocephalus: Pursuit of a smart shunt

PubMed Central

Lutz, Barry R.; Venkataraman, Pranav; Browd, Samuel R.

2013-01-01

The most common treatment for hydrocephalus is placement of a cerebrospinal fluid shunt to supplement or replace lost drainage capacity. Shunts are life-saving devices but are notorious for high failure rates, difficulty of diagnosing failure, and limited control options. Shunt designs have changed little since their introduction in 1950s, and the few changes introduced have had little to no impact on these long-standing problems. For decades, the community has envisioned a “smart shunt” that could provide advanced control, diagnostics, and communication based on implanted sensors, feedback control, and telemetry. The most emphasized contribution of smart shunts is the potential for advanced control algorithms, such as weaning from shunt dependency and personalized control. With sensor-based control comes the opportunity to provide data to the physician on patient condition and shunt function, perhaps even by a smart phone. An often ignored but highly valuable contribution would be designs that correct the high failure rates of existing shunts. Despite the long history and increasing development activity in the past decade, patients are yet to see a commercialized smart shunt. Most smart shunt development focuses on concepts or on isolated technical features, but successful smart shunt designs will be a balance between technical feasibility, economic viability, and acceptable regulatory risk. Here, we present the status of this effort and a framework for understanding the challenges and opportunities that will guide introduction of smart shunts into patient care. PMID:23653889

Slope failures in municipal solid waste dumps and landfills: a review.

PubMed

Blight, Geoffrey

2008-10-01

Between 1977 and 2005 six large-scale failures of municipal solid waste dumps and landfills have been recorded in the technical literature. The volumes of waste mobilized in the failures varied from 10-12 000 m(3) in a failure that killed nearly 300 people to 1.5 million m(3) in a failure that caused no deaths or injuries. Of the six failures, four occurred in dumps that, as far as is known, had not been subjected to any prior technical investigation of their shear stability. The remaining two failures occurred in engineer-designed landfills, one of which practised leachate recirculation, and the other co-disposed of liquid waste along with solid waste. The paper reviews, describes and analyses the failures and summarizes their causes.

Human initiated cascading failures in societal infrastructures.

PubMed

Barrett, Chris; Channakeshava, Karthik; Huang, Fei; Kim, Junwhan; Marathe, Achla; Marathe, Madhav V; Pei, Guanhong; Saha, Sudip; Subbiah, Balaaji S P; Vullikanti, Anil Kumar S

2012-01-01

In this paper, we conduct a systematic study of human-initiated cascading failures in three critical inter-dependent societal infrastructures due to behavioral adaptations in response to a crisis. We focus on three closely coupled socio-technical networks here: (i) cellular and mesh networks, (ii) transportation networks and (iii) mobile call networks. In crises, changes in individual behaviors lead to altered travel, activity and calling patterns, which influence the transport network and the loads on wireless networks. The interaction between these systems and their co-evolution poses significant technical challenges for representing and reasoning about these systems. In contrast to system dynamics models for studying these interacting infrastructures, we develop interaction-based models in which individuals and infrastructure elements are represented in detail and are placed in a common geographic coordinate system. Using the detailed representation, we study the impact of a chemical plume that has been released in a densely populated urban region. Authorities order evacuation of the affected area, and this leads to individual behavioral adaptation wherein individuals drop their scheduled activities and drive to home or pre-specified evacuation shelters as appropriate. They also revise their calling behavior to communicate and coordinate among family members. These two behavioral adaptations cause flash-congestion in the urban transport network and the wireless network. The problem is exacerbated with a few, already occurring, road closures. We analyze how extended periods of unanticipated road congestion can result in failure of infrastructures, starting with the servicing base stations in the congested area. A sensitivity analysis on the compliance rate of evacuees shows non-intuitive effect on the spatial distribution of people and on the loading of the base stations. For example, an evacuation compliance rate of 70% results in higher number of overloaded base stations than the evacuation compliance rate of 90%.

Human Initiated Cascading Failures in Societal Infrastructures

PubMed Central

Barrett, Chris; Channakeshava, Karthik; Huang, Fei; Kim, Junwhan; Marathe, Achla; Marathe, Madhav V.; Pei, Guanhong; Saha, Sudip; Subbiah, Balaaji S. P.; Vullikanti, Anil Kumar S.

2012-01-01

In this paper, we conduct a systematic study of human-initiated cascading failures in three critical inter-dependent societal infrastructures due to behavioral adaptations in response to a crisis. We focus on three closely coupled socio-technical networks here: (i) cellular and mesh networks, (ii) transportation networks and (iii) mobile call networks. In crises, changes in individual behaviors lead to altered travel, activity and calling patterns, which influence the transport network and the loads on wireless networks. The interaction between these systems and their co-evolution poses significant technical challenges for representing and reasoning about these systems. In contrast to system dynamics models for studying these interacting infrastructures, we develop interaction-based models in which individuals and infrastructure elements are represented in detail and are placed in a common geographic coordinate system. Using the detailed representation, we study the impact of a chemical plume that has been released in a densely populated urban region. Authorities order evacuation of the affected area, and this leads to individual behavioral adaptation wherein individuals drop their scheduled activities and drive to home or pre-specified evacuation shelters as appropriate. They also revise their calling behavior to communicate and coordinate among family members. These two behavioral adaptations cause flash-congestion in the urban transport network and the wireless network. The problem is exacerbated with a few, already occurring, road closures. We analyze how extended periods of unanticipated road congestion can result in failure of infrastructures, starting with the servicing base stations in the congested area. A sensitivity analysis on the compliance rate of evacuees shows non-intuitive effect on the spatial distribution of people and on the loading of the base stations. For example, an evacuation compliance rate of 70% results in higher number of overloaded base stations than the evacuation compliance rate of 90%. PMID:23118847

Endovascular stent-graft repair of failed endovascular abdominal aortic aneurysm repair.

PubMed

Baril, Donald T; Silverberg, Daniel; Ellozy, Sharif H; Carroccio, Alfio; Jacobs, Tikva S; Sachdev, Ulka; Teodorescu, Victoria J; Lookstein, Robert A; Marin, Michael L

2008-01-01

Despite high initial technical success, the long-term durability of endovascular abdominal aortic aneurysm repair (EVAR) continues to be a concern. Following EVAR, patients can experience endoleaks, device migration, device fractures, or aneurysm growth that may require intervention. The purpose of this study was to review all patients treated with secondary endovascular devices at our institution for failed EVAR procedures. Over an 8-year period, 988 patients underwent EVAR, of whom 42 (4.3%) required secondary interventions involving placement of additional endovascular devices. Data regarding patient characteristics, aneurysm size, initial device type, time until failure, failure etiology, secondary interventions, and outcomes were reviewed. The mean time from initial operation until second operation was 34.1 months. Failures included type I endoleaks in 38 patients (90.5%), type III endoleaks in two patients (4.8%), and enlarging aneurysms without definite endoleaks in two patients (4.8%). The overall technical success rate for secondary repair was 92.9% (39/42). Perioperative complications occurred in nine patients (21.4%), including wound complications (n = 6), cerebrovascular accident (CVA) (n = 1), foot drop (n = 1), and death (n = 1). Mean follow-up following secondary repair was 16.4 months (range 1-50). Eighty-six percent of patients treated with aortouni-iliac devices had successful repairs compared to 45% of patients treated with proximal cuffs. Ten patients (23.8%) had persistent or recurrent type I or type III endoleaks following revision. Of these, four had tertiary interventions, including two patients who had additional devices placed. Failures following EVAR occur in a small but significant number of patients. When anatomically possible, endovascular revision offers a safe means of treating these failures. Aortouni-iliac devices appear to offer a more durable repair than the proximal cuff for treatment of proximal type I endoleaks. Midterm results indicate that these patients may require additional procedures but have a low rate of aneurysm-related mortality. Longer-term follow-up is necessary to determine the durability of these endovascular revisions.

To the systematization of failure analysis for perturbed systems (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haller, U.

1974-01-01

The paper investigates the reliable functioning of complex technical systems. Of main importance is the question of how the functioning of technical systems which may fail or whose design still has some faults can be determined in the very earliest planning stages. The present paper is to develop a functioning schedule and to look for possible methods of systematic failure analysis of systems with stochastic failures. (RW/AK)

Comparison of EUS-guided tissue acquisition using two different 19-gauge core biopsy needles: a multicenter, prospective, randomized, and blinded study

PubMed Central

DeWitt, John; Cho, Chang-Min; Lin, Jingmei; Al-Haddad, Mohammad; Canto, Marcia Irene; Salamone, Ashley; Hruban, Ralph H.; Messallam, Ahmed A.; Khashab, Mouen A.

2015-01-01

Background and study aims: The optimal core biopsy needle for endoscopic ultrasound (EUS) is unknown. The principle aim of this study is to compare outcomes of EUS-fine-needle biopsy (EUS-FNB) with a new 19-gauge EUS histology needle (ProCore, Cook Medical Inc., Winston-Salem, North Carolina, United States) to a conventional 19-gauge Tru-Cut biopsy (EUS-TCB) needle (19G, Quick-Core, Cook Medical Inc.). Patients and methods: Patients referred for EUS who require possible histologic biopsy were prospectively randomized to EUS-FNB or EUS-TCB. With the initial needle, ≤ 3 biopsies were obtained until either technical failure or an adequate core was obtained. Patients with suspected inadequate biopsies were crossed over to the other needle and similarly ≤ 3 passes were obtained until adequate cores or technical failure occurred. Technical success, diagnostic histology, accuracy and complication rates were evaluated. Results: Eighty-five patients (mean 58 years; 43 male) were randomized to FNB (n = 44) and TCB (n = 41) with seven patients excluded. Procedure indication, biopsy site, mass size, number of passes, puncture site, overall technical success and adverse events were similar between the two groups. FNB specimens had a higher prevalence of diagnostic histology (85 % vs. 57 %; P = 0.006), accuracy (88 % vs. 62 %; P = 0.02), mean total length (19.4 vs. 4.3 mm; P = 0.001), mean complete portal triads from liver biopsies (10.4 vs. 1.3; P = 0.0004) and required fewer crossover biopsies compared to those of TCB (2 % vs. 65 %; P = 0.0001). Overall technical success and complication rates were comparable. Conclusion: EUS-FNB using a 19-gauge FNB needle is superior to 19-gauge EUS-TCB needle. PMID:26528504

Failure Rates for Fiber Optic Assemblies

DTIC Science & Technology

1980-10-01

Information Service (NTIS). At NTIS it will be releasable to the general public, including foreign nations. RADC-TR-80-322 has been reviewed and is...Literature sources searched (in addition to the RAC automated library information retrieval system) include the National Technical Information Service (NTIS...Proceedings 1976, 26th Electronic Components Conference. Price, S.J., et al. FOR RELIABLE SERVICE ENVIRONMENT PERFORMANCE, ENCAPSULATED LEDS WITH CLEAR

Measuring non-technical skills in medical emergency care: a review of assessment measures

PubMed Central

Cooper, Simon; Endacott, Ruth; Cant, Robyn

2010-01-01

Aim To review the literature on non-technical skills and assessment methods relevant to emergency care. Background Non-technical skills (NTS) include leadership, teamwork, decision making and situation awareness, all of which have an impact on healthcare outcomes. Significant concerns have been raised about the rates of adverse medical events, many of which are attributed to NTS failures. Methods Ovid, Medline, ProQUEST, PsycINFO and specialty websites were searched for NTS measures using applicable access strategies, inclusion and exclusion criteria. Publications identified were assessed for relevance. Results A range of non-technical skill measures relevant to emergency care was identified: leadership (n = 5), teamwork (n = 7), personality/behavior (n = 3) and situation awareness tools (n = 1). Of these, 9 have been used with emergency care populations/clinicians. All had varying degrees of reliability and validity. In the last decade there has been some development of teamwork measures specific to emergency care with a predominantly global and collective rating of broad skills. Conclusion A variety of non-technical skill measures are available; only a few have been used in the emergency care arena. There is a need for an increase in the focused assessment of teamwork skills for a greater understanding of team performance to enhance patient safety in medical emergency care. PMID:27147832

Lognormal Uncertainty Estimation for Failure Rates

NASA Technical Reports Server (NTRS)

Britton, Paul T.; Al Hassan, Mohammad; Ring, Robert W.

2017-01-01

"Uncertainty analysis itself is uncertain, therefore, you cannot evaluate it exactly," Source Uncertain. Quantitative results for aerospace engineering problems are influenced by many sources of uncertainty. Uncertainty analysis aims to make a technical contribution to decision-making through the quantification of uncertainties in the relevant variables as well as through the propagation of these uncertainties up to the result. Uncertainty can be thought of as a measure of the 'goodness' of a result and is typically represented as statistical dispersion. This presentation will explain common measures of centrality and dispersion; and-with examples-will provide guidelines for how they may be estimated to ensure effective technical contributions to decision-making.

MANTA, a novel plug-based vascular closure device for large bore arteriotomies: technical report.

PubMed

van Gils, Lennart; Daemen, Joost; Walters, Greg; Sorzano, Todd; Grintz, Todd; Nardone, Sam; Lenzen, Mattie; De Jaegere, Peter P T; Roubin, Gary; Van Mieghem, Nicolas M

2016-09-18

Catheter-based interventions have become a less invasive alternative to conventional surgical techniques for a wide array of cardiovascular diseases but often create large arteriotomies. A completely percutaneous technique is attractive as it may reduce the overall complication rate and procedure time. Currently, large bore arteriotomy closure relies on suture-based techniques. Access-site complications are not uncommon and often seem related to closure device failure. The MANTA VCD is a novel collagen-based closure device that specifically targets arteriotomies between 10 and 22 Fr. This technical report discusses the MANTA design concept, practical instructions for use and preliminary clinical experience.

Feasibility, efficacy, and predictive factors for the technical success of endoscopic nasogallbladder drainage: a prospective study.

PubMed

Yane, Kei; Maguchi, Hiroyuki; Katanuma, Akio; Takahashi, Kuniyuki; Osanai, Manabu; Kin, Toshifumi; Takaki, Ryo; Matsumoto, Kazuyuki; Gon, Katsushige; Matsumori, Tomoaki; Tomonari, Akiko; Nojima, Masanori

2015-03-01

Several studies have shown the useful-ness of endoscopic nasogallbladder drainage (ENGBD) in patients with acute cholecystitis. However, the procedure is difficult, and factors that affect technical success have not yet been clarified. We conducted a prospective study to eval-uate the technical feasibility, efficacy, and predictive factors for the technical success of ENGBD in patients with acute cholecystitis. All patients with moderate or severe acute cholecystitis who were enrolled underwent ENGBD between April 2009 and April 2011. Patients with surgically altered anatomy or pancreatobiliary malignancies were ex-cluded. The primary outcomes included technical success, clinical success, and complications. Factors that could affect the technical success were also examined. Of the 27 patients who underwent ENGBD during the study period, technical success was achieved in 21 (78%) and clinical improvement was achieved in 20 (95%). Early complications were encountered in four patients (15%). Gallbladder wall thickness (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.08 to 2.47) and age (OR, 1.16; 95% CI, 1.00 to 1.35) were effective predictors of technical failure. ENGBD was effective in resolving acute cholecystitis; however, this modality was technically challenging and had a limited suc-cess rate. Because of technical difficulties, ENGBD should be reserved for limited indications. (Gut Liver, 2015;9239-246).

Instrument Failures for the da Vinci Surgical System: a Food and Drug Administration MAUDE Database Study.

PubMed

Friedman, Diana C W; Lendvay, Thomas S; Hannaford, Blake

2013-05-01

Our goal was to analyze reported instances of the da Vinci robotic surgical system instrument failures using the FDA's MAUDE (Manufacturer and User Facility Device Experience) database. From these data we identified some root causes of failures as well as trends that may assist surgeons and users of the robotic technology. We conducted a survey of the MAUDE database and tallied robotic instrument failures that occurred between January 2009 and December 2010. We categorized failures into five main groups (cautery, shaft, wrist or tool tip, cable, and control housing) based on technical differences in instrument design and function. A total of 565 instrument failures were documented through 528 reports. The majority of failures (285) were of the instrument's wrist or tool tip. Cautery problems comprised 174 failures, 76 were shaft failures, 29 were cable failures, and 7 were control housing failures. Of the reports, 10 had no discernible failure mode and 49 exhibited multiple failures. The data show that a number of robotic instrument failures occurred in a short period of time. In reality, many instrument failures may go unreported, thus a true failure rate cannot be determined from these data. However, education of hospital administrators, operating room staff, surgeons, and patients should be incorporated into discussions regarding the introduction and utilization of robotic technology. We recommend institutions incorporate standard failure reporting policies so that the community of robotic surgery companies and surgeons can improve on existing technologies for optimal patient safety and outcomes.

Outcomes of second self-expandable metallic stent insertion for malignant gastric outlet obstruction.

PubMed

Kim, Chan Gyoo; Choi, Il Ju; Lee, Jong Yeul; Cho, Soo-Jeong; Kim, Soo Jin; Kim, Mi-Jung; Park, Sook Ryun; Park, Young Lee

2014-01-01

Self-expandable metallic stents are used widely to relieve malignant gastric outlet obstruction (GOO). However, restenosis or migration of first stents is a frequent complication. The purpose of this retrospective cohort study was to evaluate the effectiveness of second stents as an approach to manage failure of first stents in patients with malignant GOO. A total of 222 patients with gastric cancer received first stents due to inoperable GOO at National Cancer Center in Korea between January 2008 and June 2011. Monthly follow-up interviews were performed, and second stents (stent-in-stent or stent-after-migration) were inserted in 59 patients by June 2012. Technical and clinical successes and long-term complications were evaluated. The technical and immediate clinical success rates were 98.3 % (58/59) and 91.5 % (54/59), respectively. Patients who received a second stent due to late complications involving the first stent (migration, restenosis, and fracture) showed a higher clinical success rate (95.8 % [46/48]) than patients who received a second stent due to immediate clinical failure of the first stent (72.7 % [8/11], p = 0.04). The immediate clinical success rate of stent-after-migration (100 % [11/11]) was not different from that of stent-in-stent (89.6 % [43/48], p = 1.0). The stent dysfunction rate of stent-after-migration (27.3 % [3/11]) also was similar to that of stent-in-stent (29.2 % [14/48], p = 1.0). The median patencies of stent-in-stent and stent-after-migration were 27.4 and 58.4 weeks, respectively (p = 0.177). There were no significant prognostic factors for patency of second stents. Insertion of a second stent is effective for treating the first-stent failure in gastric cancer patients with GOO, especially if the immediate outcome of the first stent was successful.

Micro Navigator (MICRON) Phase 2A. Volume 1. Technical Report

DTIC Science & Technology

1976-02-01

350 6-56. AMESGA Test Log Summary.................................. 351 xv ’I LIST OF TABLES (Cant) Tables Page 6-57. MESGA Calibration Table...of Module Slc xs Failure Rate Normalized to the Baseline Estimates 178 6.2.3.4 Packaging Alternative Studies Cost of ownership evaluations were...130 were step-heated and monitored. Significant outgas - sing of non-getterable gases was detected. These observations raised a serious question as to

[The complications of skin expansion in paediatrics: Diagnostic, taking over and prevention].

PubMed

Pascal, S; Philandrianos, C; Bertrand, B; Bardot, J; Degardin, N; Casanova, D

2016-10-01

Skin expansion is a difficult and long process in which can occur more or less serious complications. Overall complications rates describe in the literature vary between 13 and 37%. We can categorize them in major complications, which can lead to a failure maybe even an aggravation of the anterior status, and in minor complications that do not compromise the expansion process but can alter it. The main major complications are infection, skin suffering and necrosis which can lead to prosthesis exposition, leaks and technical problems with equipment dysfunctions that may cause difficulties or a failure of the inflations. The main minor complications are hematomas, seromas, valve or tube exposition, pains with paraesthesias caused by neighbouring organs compression, pathologic and unsightly scares and can lead to an important psychological impact. These complications can be due to a precarious skin's state, a material dysfunction or unpredictable technical problems but also by an inappropriate preoperative indication or planning. The emerging of a complication, however, is not synonymous to a failure of the procedure; a satisfactory reconstruction may still be obtained in 75% of all cases. The purpose of this article is to help to identify the situations at risk of complications in order to prevent, detect and treat them early. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Report: Searching for a way to sustainability: technical and policy analyses of solid waste issues in Kathmandu.

PubMed

Dangi, Mohan B; Cohen, Ronald R H; Urynowicz, Michael A; Poudyal, Khem N

2009-05-01

Kathmandu Metropolitan City has attempted to reorganize its solid waste management a number of times. The German Technical and Financial Aid Organization led early efforts that were followed by a number of more recent experiments that left the city with an unsustainable solid waste management system following the termination of foreign aid. To examine this failure, the research team evaluated household surveys, field observations, interviews, and other primary and secondary information within the context of technical, social, and institutional analyses. The survey results show that the solid waste collection rates are far below the 90% claimed by the metropolis and street sweeping consumes approximately 51% of its solid waste budget. As a result of the relatively low collection rates the city residents are encouraged to dump waste into public lands. Consequently, too much of the city's resources are focused on sweeping rather than collection. Kathmandu needs to recognize informal waste picking, privatize, use local techniques, build capacity, promote bottom-up and participatory styles of management, and regulate policies to maintain solid waste management.

New Treatments for Infrapopliteal Disease: Devices, Techniques, and Outcomes So Far

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernstein, Ondina; Chalmers, Nicholas, E-mail: nicholas.chalmers@cmft.nhs.uk

2012-08-15

The use of endovascular treatment of infrapopliteal disease has increased in popularity in recent years. An improvement in technical success rates due to the availability of newer devices has fuelled an increased interest in the subject. The pathogenesis, indications for treatment, and outcome measures of infrapopliteal disease differ from larger vessel intervention. Diabetes and renal failure are prevalent. Neuropathy and venous disease contribute to the etiology of ulceration. Most interventions are undertaken for critical limb ischemia rather than claudication. Therefore, a range of conservative, pharmacological, and invasive therapies are provided. Conventional percutaneous transluminal angioplasty (PTA) using modern low-profile systems ismore » associated with high technical success rates. However, initial data from recent randomized, controlled trials suggest that drug-eluting stents are consistently achieving improved patency over PTA alone or over bare metal stents. This review summarizes recent advances in the treatment of infrapopliteal disease.« less

Comprehensive Deployment Method for Technical Characteristics Base on Multi-failure Modes Correlation Analysis

NASA Astrophysics Data System (ADS)

Zheng, W.; Gao, J. M.; Wang, R. X.; Chen, K.; Jiang, Y.

2017-12-01

This paper put forward a new method of technical characteristics deployment based on Reliability Function Deployment (RFD) by analysing the advantages and shortages of related research works on mechanical reliability design. The matrix decomposition structure of RFD was used to describe the correlative relation between failure mechanisms, soft failures and hard failures. By considering the correlation of multiple failure modes, the reliability loss of one failure mode to the whole part was defined, and a calculation and analysis model for reliability loss was presented. According to the reliability loss, the reliability index value of the whole part was allocated to each failure mode. On the basis of the deployment of reliability index value, the inverse reliability method was employed to acquire the values of technology characteristics. The feasibility and validity of proposed method were illustrated by a development case of machining centre’s transmission system.

Successful revascularization of chronic total occlusion of lower extremity arteries: a wire only and bail out use of re-entry device approach.

PubMed

Langhoff, R; Stumpe, S; Treitl, M; Schulte, K L

2013-10-01

The management of progressive peripheral artery disease experienced a vast change in paradigms over the last decades for the benefit of minimal invasive therapy as a first-line strategy. With the constant development of new devices, materials and dedicated access strategies, more complex lesions can be managed but the limitations to successfully treat chronic total occlusions are still the challenge to re-enter the true lumen. The aim of this retrospective study was to investigate, if a "wire only" strategy leads to an acceptable success rate in a mixed cohort of CTO lesions and to what extend re-entry devices are used. We retrospectively analyzed patients treated at the Vascular Center Berlin between 2011 and 2013 with chronic total occlusion out of a prospective conducted database (Endovascular MILestones - EMIL) for demographics, risk factors, co-morbidities, technical success rates, lesion characteristics and use of guidewires as well as re-entry systems. A total of 128 patients with 146 lesions, which represent a subgroup of all the cases performed in our center, following a predefined treatment algorithm for chronic total occlusions (CTOs), have been analyzed. We achieved a technical success in 133 (91.1%) of all cases following a "wire only" strategy. Out of 13 (8.9%) CTOs with technical failure in 7 (53.9%) CTOs a re-entry device (Off-Road®) with a 100% technical success has been used. In 91.1% of chronic total occlusion lesions the use of 2 wires only (88.7%) led to a successful recanalization. A "wire only" strategy followed by the use of a re-entry device as a bail out strategy, led to a total of 140 (96%) lesions to be successfully recanalized. In more than 90% of all cases with chronic total occlusion of peripheral lower extremity arteries, endovascular intervention has been successful following a "wire only" strategy. When deciding to use a re-entry device, in case of a failure of a proper wire re-entry at the reconstitution point, a technical success rate of 100% was achieved. Therefore following a strict wire algorithm and considering the use of a re-entry system as a bail out strategy will lead to a successful minimal invasive management of chronic total occlusion in nearly 100% of the cases with TASC II A - D lesions.

Technical and Clinical Results After Percutaneous Angioplasty in Nonmedial Fibromuscular Dysplasia: Outcome After Endovascular Management of Unifocal Renal Artery Stenoses in 30 Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barrier, Pierre, E-mail: p.barrier@gmail.com; Julien, Auriol; Guillaume, Canevet

2010-04-15

Although percutaneous transluminal renal angioplasty (PTRA) is associated with excellent results in medial fibromuscular dysplasia (FMD), the clinical and technical outcome in the less common nonmedial subtype of FMD is not clearly known. Angiographic PTRA results and clinical follow-up were documented, to report technical and clinical results in 30 patients with unifocal, nonmedial dysplastic stenoses. Balloon angioplasty was technically successful in only 65% of the lesions. Additional stenting, performed after PTRA failure in six patients, increased the initial technical success rate to 82%. Stenting was used in another lesion after restenosis, and long-term patency was achieved in only three ofmore » the seven stented lesions. Frequent restenoses and unusual complications were observed during follow-up. Stent fracture occurred in two cases. Overall, long-term clinical and technical successes were sustained in 70 and 76%, respectively. We conclude that nonmedial, unifocal renal artery dysplastic stenoses do not share the excellent prognosis of the medial type and that stenting should be avoided. Therefore, surgery should be considered in lesions remaining unresponsive to balloon dilatation, after a second PTRA attempt.« less

Reliability and availability analysis of a 10 kW@20 K helium refrigerator

NASA Astrophysics Data System (ADS)

Li, J.; Xiong, L. Y.; Liu, L. Q.; Wang, H. R.; Wang, B. M.

2017-02-01

A 10 kW@20 K helium refrigerator has been established in the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences. To evaluate and improve this refrigerator’s reliability and availability, a reliability and availability analysis is performed. According to the mission profile of this refrigerator, a functional analysis is performed. The failure data of the refrigerator components are collected and failure rate distributions are fitted by software Weibull++ V10.0. A Failure Modes, Effects & Criticality Analysis (FMECA) is performed and the critical components with higher risks are pointed out. Software BlockSim V9.0 is used to calculate the reliability and the availability of this refrigerator. The result indicates that compressors, turbine and vacuum pump are the critical components and the key units of this refrigerator. The mitigation actions with respect to design, testing, maintenance and operation are proposed to decrease those major and medium risks.

A critical analysis of early death after adult liver transplants.

PubMed

Rana, Abbas; Kaplan, Bruce; Jie, Tun; Porubsky, Marian; Habib, Shahid; Rilo, Horacio; Gruessner, Angelika C; Gruessner, Rainer W G

2013-01-01

The 15% mortality rate of liver transplant recipients at one yr may be viewed as a feat in comparison with the waiting list mortality, yet it nonetheless leaves room for much improvement. Our aim was to critically examine the mortality rates to identify high-risk periods and to incorporate cause of death into the analysis of post-transplant survival. We performed a retrospective analysis on United Network for Organ Sharing data for all adult recipients of liver transplants from January 1, 2002 to October 31, 2011. Our analysis included multivariate logistic regression where the primary outcome measure was patient death of 49,288 recipients. The highest mortality rate by day post-transplant was on day 0 (0.9%). The most significant risk factors were as follows: for one-d mortality from technical failure, intensive care unit admission odds ratio (OR 3.2); for one-d mortality from graft failure, warm ischemia >75 min (OR 5.6); for one-month mortality from infection, a previous transplant (OR 3.3); and for one-month mortality from graft failure, a previous transplant (OR 3.7). We found that the highest mortality rate after liver transplantation is within the first day and the first month post-transplant. Those two high-risk periods have common, as well as different, risk factors for mortality. © 2013 John Wiley & Sons A/S.

Endovascular Revascularization of Chronically Thrombosed Arteriovenous Fistulas and Grafts for Hemodialysis: A Retrospective Study in 15 Patients With 18 Access Sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weng Meijui; Chen, Matt Chiung-Yu, E-mail: jjychen@gmail.com; Chi Wenche

2011-04-15

The current study retrospectively evaluated whether endovascular revascularization of chronically thrombosed and long-discarded vascular access sites for hemodialysis was feasible. Technical and clinical success rates, postintervention primary and secondary patency rates, and complications were reported. During a 1-year period, we reviewed a total of 924 interventions performed for dysfunction and/or failed hemodialysis vascular access sites and permanent catheters in 881 patients. In patients whose vascular access-site problems were considered untreatable or were considered treatable with a high risk of failure and access-site abandonment, we attempted to revascularize (resurrect) the chronically occluded and long-discarded (mummy) vascular access sites. We attempted tomore » resurrect a total of 18 mummy access sites (mean age 46.6 {+-} 38.7 months; range 5-144) in 15 patients (8 women and 7 men; mean age 66.2 {+-} 11.5 years; age range 50-85) and had an overall technical success rate of 77.8%. Resurrection failure occurred in 3 fistulas and in 1 straight graft. The clinical success rate was 100% at 2 months after resurrection. In the 14 resurrected vascular access sites, 6 balloon-assisted maturation procedures were required in 5 fistulas; after access-site maturation, a total of 22 interventions were performed to maintain access-site patency. The mean go-through time for successful resurrection procedures was 146.6 {+-} 34.3 min (range 74-193). Postmaturation primary patency rates were 71.4 {+-} 12.1% at 30 days, 57.1 {+-} 13.2% at 60 days, 28.6 {+-} 13.4% at 90 days, and 19 {+-} 11.8% at 180 days. Postmaturation secondary patency rates were 100% at 30, 60, and 90 days and 81.8 {+-} 11.6% at 180 days. There were 2 major complications consisting of massive venous ruptures in 2 mummy access sites during balloon dilation; in both cases, prolonged balloon inflation failed to achieve hemostasis, but percutaneous N-butyl cyanoacrylate glue seal-off was performed successfully. Percutaneous resurrection of mummy vascular access sites for hemodialysis is technically feasible with high clinical success rates. In selected patients, resurrection of mummy access sites provides long-discarded access sites one more chance to be used for hemodialysis in an effort to preserve potential extremity sites for future access-site placement and to prevent long-term catheter indwelling.« less

Presurgical motor, somatosensory and language fMRI: Technical feasibility and limitations in 491 patients over 13 years.

PubMed

Tyndall, Anthony J; Reinhardt, Julia; Tronnier, Volker; Mariani, Luigi; Stippich, Christoph

2017-01-01

To analyse the long-term feasibility and limitations of presurgical fMRI in a cohort of tumour and epilepsy patients with different MR-scanners at 1.5 and 3.0 T. Four hundred and ninety-one consecutive patients undergoing presurgical fMRI between 2000 and 2012 on five different MR-scanners using established paradigms and semi-automated data processing were included. Success rates of task performance and BOLD-activation were determined for motor and somatosensory somatotopic mapping and language localisation. Procedural success, failures and imaging artifacts were analysed. MR-field strengths were compared. Two thousand three hundred fifteen of 2348 (98.6 %) attempted paradigms (1033 motor, 1220 speech, 95 somatosensory) were successfully performed. 100 paradigms (4.3 %) were repetition runs. 23 speech, 6 motor and 2 sensory paradigms failed for non-compliance and technical issues. Most language paradigm failures were noted in overt sentence generation. Average significant BOLD-activation was higher for motor than language paradigms (95.8 vs. 81.6 %). Most language paradigms showed significantly higher activation rates at 3 T compared to 1.5 T, whereas no significant difference was found for motor paradigms. fMRI proved very robust for the presurgical localisation of the different motor and somatosensory body representations, as well as Broca's and Wernicke's language areas across different MR-scanners at 1.5 and 3.0 T over 13 years. • Standardised presurgical motor and language fMRI is robust across various MRI platforms. • Motor fMRI is less dependent on field strength than language fMRI. • fMRI task failures are relatively low and are reduced by paradigm repetition.

Instructional Changes Adopted for an Engineering Course: Cluster Analysis on Academic Failure

PubMed Central

Álvarez-Bermejo, José A.; Belmonte-Ureña, Luis J.; Martos-Martínez, África; Barragán-Martín, Ana B.; Simón-Márquez, María M.

2016-01-01

As first year students come from diverse backgrounds, basic skills should be accessible to everyone as soon as possible. Transferring such skills to these students is challenging, especially in highly technical courses. Ensuring that essential knowledge is acquired quickly promotes the student’s self-esteem and may positively influence failure rates. Metaphors can help do this. Metaphors are used to understand the unknown. This paper shows how we made a turn in student learning at the University of Almeria. Our hypothesis assumed that metaphors accelerate the acquisition of basic knowledge so that other skills built on that foundation are easily learned. With these goals in mind, we changed the way we teach by using metaphors and abstract concepts in a computer organization course, a technical course in the first year of an information technology engineering degree. Cluster analysis of the data on collective student performance after this methodological change clearly identified two distinct groups. These two groups perfectly matched the “before and after” scenarios of the use of metaphors. The study was conducted during 11 academic years (2002/2003 to 2012/2013). The 475 observations made during this period illustrate the usefulness of this change in teaching and learning, shifting from a propositional teaching/learning model to a more dynamic model based on metaphors and abstractions. Data covering the whole period showed favorable evolution of student achievement and reduced failure rates, not only in this course, but also in many of the following more advanced courses. The paper is structured in five sections. The first gives an introduction, the second describes the methodology. The third section describes the sample and the study carried out. The fourth section presents the results and, finally, the fifth section discusses the main conclusions. PMID:27895611

Semiannual Technical Summary, 1 April-30 September 1993

DTIC Science & Technology

1993-12-01

Hardware failure 11 Jul 2200 - Hardware failure 12 Jul - 0531 Hardware failure 12 Jul 0744 - 1307 Hardware service 1OAug 0821 - 1514 Line failure 29 Aug...1000 - Line failure 30 Aug - 1211 Line failure 08 Sep 1518 - Line failure 09 Sep - 0428 Line failure 10 Sep 0821 - 1030 Hardware failure 18 Sep 0817...reair. Between 8 September 1306 hrs and 9 September 0428 hre all communications systems wene affected (13.5 hrs). Reduced 01B performance started 10

Iridium: failures & successes

NASA Astrophysics Data System (ADS)

Christensen, CarissaBryce; Beard, Suzette

2001-03-01

This paper will provide an overview of the Iridium business venture in terms of the challenges faced, the successes achieved, and the causes of the ultimate failure of the venture — bankruptcy and system de-orbit. The paper will address technical, business, and policy issues. The intent of the paper is to provide a balanced and accurate overview of the Iridium experience, to aid future decision-making by policy makers, the business community, and technical experts. Key topics will include the history of the program, the objectives and decision-making of Motorola, the market research and analysis conducted, partnering strategies and their impact, consumer equipment availability, and technical issues — target performance, performance achieved, technical accomplishments, and expected and unexpected technical challenges. The paper will use as sources trade media and business articles on the Iridium program, technical papers and conference presentations, Wall Street analyst's reports, and, where possible, interviews with participants and close observers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goltz, Jan P., E-mail: Goltz@roentgen.uni-wuerzburg.de; Scholl, Anne; Ritter, Christian O.

The aim of this study is to evaluate the effectiveness and safety of percutaneously placed totally implantable venous-access ports (TIVAPs) of the forearm. Between January 2006 and October 2008, peripheral TIVAPs were implanted in 763 consecutive patients by ultrasound and fluoroscopic guidance. All catheters were implanted under local anesthesia and were tunneled subcutaneously. Indication, technical success, and complications were retrospectively analyzed according to Society of Interventional Radiology (SIR) criteria. Presence of antibiotic prophylaxis, periprocedurally administered drugs (e.g., sedation), and laboratory results at the time of implantation were analyzed. Maintenance during the service interval was evaluated. In total, 327,499 catheter-days weremore » analyzed. Technical success rate was 99.3%. Reasons for initial failure of implantation were either unexpected thrombosis of the subclavian vein, expanding tumor mass of the mediastinum, or failure of peripheral venous access due to fragile vessels. Mean follow-up was 430 days. There were 115 complications observed (15.1%, 0.03 per 100 catheter-days), of which 33 (4.3%) were classified as early (within 30 days from implantation) and 82 (10.7%) as late. Catheter-related venous thrombosis was found in 65 (8.5%) of 763 (0.02 per 100 catheter-days) TIVAPs. Infections were observed in 41 (5.4%) of 763 (0.01 per 100 catheter-days) devices. Other complications observed included dislocation of the catheter tip (0.8%), occlusion (0.1%), or rupture (0.1%) of the port catheter. Dislocated catheters were corrected during a second interventional procedure. In conclusion, implantation of percutaneously placed peripheral TIVAPs shows a high technical success rate and low risk of early complications when ultrasound and fluoroscopic guidance are used. Late complications are observed three times as often as early complications.« less

Improving the retrieval rate of inferior vena cava filters with a multidisciplinary team approach

PubMed Central

Inagaki, Elica; Farber, Alik; Eslami, Mohammad H.; Siracuse, Jeffrey J.; Rybin, Denis V.; Sarosiek, Shayna; Sloan, J. Mark; Kalish, Jeffrey

2017-01-01

Objective The option to retrieve inferior vena cava (IVC) filters has resulted in an increase in the utilization of these devices as stopgap measures in patients with relative contraindications to anticoagulation. These retrievable IVC filters, however, are often not retrieved and become permanent. Recent data from our institution confirmed a historically low retrieval rate. Therefore, we hypothesized that the implementation of a new IVC filter retrieval protocol would increase the retrieval rate of appropriate IVC filters at our institution. Methods All consecutive patients who underwent an IVC filter placement at our institution between September 2003 and July 2012 were retrospectively reviewed. In August 2012, a multidisciplinary task force was established, and a new IVC filter retrieval protocol was implemented. Prospective data were collected using a centralized interdepartmental IVC filter registry for all consecutive patients who underwent an IVC filter placement between August 2012 and September 2014. Patients were chronologically categorized into preimplementation (PRE) and postimplementation (POST) groups. Comparisons of outcome measures, including the retrieval rate of IVC filters along with rates of retrieval attempt and technical failure, were made between the two groups. Results In the PRE and POST groups, a total of 720 and 74 retrievable IVC filters were implanted, respectively. In the POST group, 40 of 74 filters (54%) were successfully retrieved compared with 82 of 720 filters (11%) in the PRE group (P < .001). Furthermore, a greater number of IVC filter retrievals were attempted in the POST group than in the PRE group (66% vs 14%; P < .001). No significant difference was observed between the PRE and POST groups for technical failure (17% vs 18%; P = .9). Conclusions The retrieval rate of retrievable IVC filters at our institution was significantly increased with the implementation of a new IVC filter retrieval protocol with a multidisciplinary team approach. This improved retrieval rate is possible with minimal dedication of resources and can potentially lead to a decrease in IVC filter-related complications in the future. PMID:27318045

Impact of graft implantation order on graft survival in simultaneous pancreas-kidney transplantation.

PubMed

Niclauss, Nadja; Bédat, Benoît; Morel, Philippe; Andres, Axel; Toso, Christian; Berney, Thierry

2016-05-01

The optimal order of revascularization for pancreas and kidney grafts in simultaneous pancreas-kidney transplantation has not been established. In this study, we investigate the influence of graft implantation order on graft survival in SPK. 12 700 transplantations from the Scientific Registry of Transplant Recipients were analyzed retrospectively. Graft implantation order was determined based on the reported ischemia times of pancreas and kidney grafts. Pancreas and kidney graft survivals were analyzed depending on graft implantation order at 3 months and 5 years using Kaplan-Meier plots. Significance was tested with log-rank test and Cox regression model. In 8454 transplantations, the pancreas was implanted first (PBK), and in 4246 transplantations, the kidney was implanted first (KBP). The proportion of lost pancreas grafts at 3 months was significantly lower in PBK (9.4% vs. 10.8%, P = 0.011). Increasing time lag (>2 h) between kidney and pancreas graft implantation in KBP accentuated the detrimental impact on pancreas graft survival (12.5% graft loss at 3 months, P = 0.001). Technical failure rates were reduced in PBK (5.6 vs. 6.9%, P = 0.005). Graft implantation order had no impact on kidney graft survival. In summary, although observed differences are small, pancreas graft implantation first increases short-term pancreas graft survival and reduces rates of technical failure. © 2016 Steunstichting ESOT.

National audit of the sensitivity of double-contrast barium enema for colorectal carcinoma, using control charts For the Royal College of Radiologists Clinical Radiology Audit Sub-Committee.

PubMed

Tawn, D J; Squire, C J; Mohammed, M A; Adam, E J

2005-05-01

To audit the sensitivity of double-contrast barium enema (DCBE) for colorectal carcinoma, as currently practised in UK departments of radiology. As part of its programme of national audits, the Royal College of Radiologists Clinical Radiology Audit Sub-Committee undertook a retrospective audit of the sensitivity of DCBE for colorectal carcinoma during 2002. The following targets were set: demonstration of a lesion > or =95%; correct identification as a carcinoma > or =90%. Across the UK, 131 departments took part in the audit, involving 5454 examinations. The mean demonstration rate was 92.9% and the diagnosis rate was 85.9%, slightly below the targets set. The equivocal rate (lesion demonstrated, but not defined as malignant) was 6.9%, the perception failure rate was 2.8% and the technical failure rate was 4.4%. Control-chart methodology was used to analyze the data and to identify any departments whose performance was consistent with special-cause variation. When compared with the diagnosis rate (84.6%) and demonstration rate (92.7%) reported in the Wessex Audit 1995, [Thomas RD, Fairhurst JJ, Frost RA. Wessex regional audit: barium enema in colo-rectal carcinoma. Clin Radiol 1995;50:647-50.] a similar level of performance was observed in the NHS today, implying that the basic process for undertaking and reporting DCBE has remained relatively unchanged over the last few years. Improvement in the future will require fundamental changes to the process of reporting DCBE, in order to minimize the perception failure rate and accurately to describe lesions, so reducing the equivocal rate. Control-chart methodology has a useful role in identifying strategies to deliver continual improvement.

Reducing error and improving efficiency during vascular interventional radiology: implementation of a preprocedural team rehearsal.

PubMed

Morbi, Abigail H M; Hamady, Mohamad S; Riga, Celia V; Kashef, Elika; Pearch, Ben J; Vincent, Charles; Moorthy, Krishna; Vats, Amit; Cheshire, Nicholas J W; Bicknell, Colin D

2012-08-01

To determine the type and frequency of errors during vascular interventional radiology (VIR) and design and implement an intervention to reduce error and improve efficiency in this setting. Ethical guidance was sought from the Research Services Department at Imperial College London. Informed consent was not obtained. Field notes were recorded during 55 VIR procedures by a single observer. Two blinded assessors identified failures from field notes and categorized them into one or more errors by using a 22-part classification system. The potential to cause harm, disruption to procedural flow, and preventability of each failure was determined. A preprocedural team rehearsal (PPTR) was then designed and implemented to target frequent preventable potential failures. Thirty-three procedures were observed subsequently to determine the efficacy of the PPTR. Nonparametric statistical analysis was used to determine the effect of intervention on potential failure rates, potential to cause harm and procedural flow disruption scores (Mann-Whitney U test), and number of preventable failures (Fisher exact test). Before intervention, 1197 potential failures were recorded, of which 54.6% were preventable. A total of 2040 errors were deemed to have occurred to produce these failures. Planning error (19.7%), staff absence (16.2%), equipment unavailability (12.2%), communication error (11.2%), and lack of safety consciousness (6.1%) were the most frequent errors, accounting for 65.4% of the total. After intervention, 352 potential failures were recorded. Classification resulted in 477 errors. Preventable failures decreased from 54.6% to 27.3% (P < .001) with implementation of PPTR. Potential failure rates per hour decreased from 18.8 to 9.2 (P < .001), with no increase in potential to cause harm or procedural flow disruption per failure. Failures during VIR procedures are largely because of ineffective planning, communication error, and equipment difficulties, rather than a result of technical or patient-related issues. Many of these potential failures are preventable. A PPTR is an effective means of targeting frequent preventable failures, reducing procedural delays and improving patient safety.

Percutaneous biliary approach as a successful rescue procedure after failed endoscopic therapy for drainage in advanced hilar tumors.

PubMed

Jang, Sung Ill; Hwang, Jin-Hyeok; Lee, Kwang-Hun; Yu, Jeong-Sik; Kim, Hee Wook; Yoon, Chang Jin; Lee, Yoon Suk; Paik, Kyu Hyun; Lee, Sang Hyub; Lee, Dong Ki

2017-04-01

Palliative endoscopic or percutaneous biliary drainage is used for unresectable advanced hilar cancer (HC). The best option for drainage in Bismuth type III or IV HC has not been established. The aims of this study are to identify factors predictive of endoscopic stenting failure and evaluate the effectiveness of rescue percutaneous stenting in patients with advanced HC. Data from 110 patients with inoperable advanced HC were retrospectively reviewed. All received bilateral self-expandable metallic stents. Patients were divided into three groups: I, successful initial endoscopic stenting; II, unsuccessful initial endoscopic stenting, followed by percutaneous stenting; and III, initial percutaneous stenting. We analyzed clinical results and radiologic tumor characteristics. Baseline characteristics and clinical outcomes of all groups were similar, except the hospital stay was longer in group III than group I. Technical success rate was higher in groups II and III (100%) than in group I (72.4%). The functional success rate, stent patency time, patient survival time, and complication rate were similar between groups. Endoscopic stenting failed because of guide-wire passage failure (n = 12) or stent passage failure (n = 7). The only factor significantly associated with endoscopic failure was a smaller left intrahepatic duct-common bile duct angle. As clinical outcomes were generally similar between approaches, percutaneous stenting is recommended for patients with Bismuth type III or IV advanced HC. Acute left intrahepatic duct-common bile duct angulation predicts endoscopic stenting failure. If endoscopic stenting fails, immediate conversion to the percutaneous approach is a necessary and effective rescue method. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Characterization of mechanical damage mechanisms in ceramic composite materials. Technical report, 23 May 1987-24 May 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lankford, J.

High-strain-rate compressive failure mechanisms in fiber-reinforced ceramic-matrix composite materials were characterized. These are contrasted with composite damage development at low-strain rates, and with the dynamic failure of monolithic ceramics. It is shown that it is possible to derive major strain-rate strengthening benefits if a major fraction of the fiber reinforcement is aligned with the load axis. This effect considerably exceeds the inertial microfracture strengthening observed in monolithic ceramics, and non-aligned composites. Its basis is shown to be the trans-specimen propagation time period for heterogeneously-nucleated, high-strain kink bands. A brief study on zirconia focused on the remarkable inverse strength-strain rate resultmore » previously observed for both fully and partially-stabilized zirconia single crystals, whereby the strength decreased with increasing strain rate. Based on the hypothesis that the suppression of microplastic flow, hence, local stress relaxation, might be responsible for this behavior, fully stabilized (i.e., non-transformable) specimens were strain-gaged and subjected to compressive microstrain. The rather stunning observation was that the crystals are highly microplastic, exhibiting plastic yield on loading and anelasticity and reverse plasticity upon unloading. These results clearly support the hypothesis that with increasing strain rate, microcracking is favored at the expense of microplasticity.« less

Do heart and respiratory rate variability improve prediction of extubation outcomes in critically ill patients?

PubMed Central

2014-01-01

Introduction Prolonged ventilation and failed extubation are associated with increased harm and cost. The added value of heart and respiratory rate variability (HRV and RRV) during spontaneous breathing trials (SBTs) to predict extubation failure remains unknown. Methods We enrolled 721 patients in a multicenter (12 sites), prospective, observational study, evaluating clinical estimates of risk of extubation failure, physiologic measures recorded during SBTs, HRV and RRV recorded before and during the last SBT prior to extubation, and extubation outcomes. We excluded 287 patients because of protocol or technical violations, or poor data quality. Measures of variability (97 HRV, 82 RRV) were calculated from electrocardiogram and capnography waveforms followed by automated cleaning and variability analysis using Continuous Individualized Multiorgan Variability Analysis (CIMVA™) software. Repeated randomized subsampling with training, validation, and testing were used to derive and compare predictive models. Results Of 434 patients with high-quality data, 51 (12%) failed extubation. Two HRV and eight RRV measures showed statistically significant association with extubation failure (P <0.0041, 5% false discovery rate). An ensemble average of five univariate logistic regression models using RRV during SBT, yielding a probability of extubation failure (called WAVE score), demonstrated optimal predictive capacity. With repeated random subsampling and testing, the model showed mean receiver operating characteristic area under the curve (ROC AUC) of 0.69, higher than heart rate (0.51), rapid shallow breathing index (RBSI; 0.61) and respiratory rate (0.63). After deriving a WAVE model based on all data, training-set performance demonstrated that the model increased its predictive power when applied to patients conventionally considered high risk: a WAVE score >0.5 in patients with RSBI >105 and perceived high risk of failure yielded a fold increase in risk of extubation failure of 3.0 (95% confidence interval (CI) 1.2 to 5.2) and 3.5 (95% CI 1.9 to 5.4), respectively. Conclusions Altered HRV and RRV (during the SBT prior to extubation) are significantly associated with extubation failure. A predictive model using RRV during the last SBT provided optimal accuracy of prediction in all patients, with improved accuracy when combined with clinical impression or RSBI. This model requires a validation cohort to evaluate accuracy and generalizability. Trial registration ClinicalTrials.gov NCT01237886. Registered 13 October 2010. PMID:24713049

Assessing team performance in the operating room: development and use of a "black-box" recorder and other tools for the intraoperative environment.

PubMed

Guerlain, Stephanie; Adams, Reid B; Turrentine, F Beth; Shin, Thomas; Guo, Hui; Collins, Stephen R; Calland, J Forrest

2005-01-01

The objective of this research was to develop a digital system to archive the complete operative environment along with the assessment tools for analysis of this data, allowing prospective studies of operative performance, intraoperative errors, team performance, and communication. Ability to study this environment will yield new insights, allowing design of systems to avoid preventable errors that contribute to perioperative complications. A multitrack, synchronized, digital audio-visual recording system (RATE tool) was developed to monitor intraoperative performance, including software to synchronize data and allow assignment of independent observational scores. Cases were scored for technical performance, participants' situational awareness (knowledge of critical information), and their comfort and satisfaction with the conduct of the procedure. Laparoscopic cholecystectomy (n = 10) was studied. Technical performance of the RATE tool was excellent. The RATE tool allowed real time, multitrack data collection of all aspects of the operative environment, while permitting digital recording of the objective assessment data in a time synchronized and annotated fashion during the procedure. The mean technical performance score was 73% +/- 28% of maximum (perfect) performance. Situational awareness varied widely among team members, with the attending surgeon typically the only team member having comprehensive knowledge of critical case information. The RATE tool allows prospective analysis of performance measures such as technical judgments, team performance, and communication patterns, offers the opportunity to conduct prospective intraoperative studies of human performance, and allows for postoperative discussion, review, and teaching. This study also suggests that gaps in situational awareness might be an underappreciated source of operative adverse events. Future uses of this system will aid teaching, failure or adverse event analysis, and intervention research.

Developing guidelines for repairing severe edge failures : technical report.

DOT National Transportation Integrated Search

2014-04-01

This report presents various edge failures, the methods used by districts to repair them, and the results of the : repair. While there was no clear consensus on the best treatment of in-situ material for pavements with edge : failures, the districts ...

Methods of measurement for semiconductor materials, process control, and devices

NASA Technical Reports Server (NTRS)

Bullis, W. M. (Editor)

1972-01-01

Activities directed toward the development of methods of measurement for semiconductor materials, process control, and devices are described. Topics investigated include: measurements of transistor delay time; application of the infrared response technique to the study of radiation-damaged, lithium-drifted silicon detectors; and identification of a condition that minimizes wire flexure and reduces the failure rate of wire bonds in transistors and integrated circuits under slow thermal cycling conditions. Supplementary data concerning staff, standards committee activities, technical services, and publications are included as appendixes.

[The applied of computer for analysis on contraceptive efficacy of IUD of rural women in Guangdong province].

PubMed

Jia, G H

1989-12-01

This paper discussed the usage and effect of IUD-type O use for rural married women in Guangdong province. The continuation rate of IUD-type O is 71.7 per cent 100 women in one year. The main problem for failure was expulsion. This paper have used a combination of univariate and multivariate analytic methods. On the whole, the important factors were number of gravid and parity, number of induced abortion and medical technical level etc.

76 FR 10671 - Assessments, Large Bank Pricing

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-25

...The FDIC is amending its regulations to implement revisions to the Federal Deposit Insurance Act made by the Dodd-Frank Wall Street Reform and Consumer Protection Act (``Dodd-Frank'') by modifying the definition of an institution's deposit insurance assessment base; to change the assessment rate adjustments; to revise the deposit insurance assessment rate schedules in light of the new assessment base and altered adjustments; to implement Dodd-Frank's dividend provisions; to revise the large insured depository institution assessment system to better differentiate for risk and better take into account losses from large institution failures that the FDIC may incur; and to make technical and other changes to the FDIC's assessment rules.

Da Vinci robot error and failure rates: single institution experience on a single three-arm robot unit of more than 700 consecutive robot-assisted laparoscopic radical prostatectomies.

PubMed

Zorn, Kevin C; Gofrit, Ofer N; Orvieto, Marcelo A; Mikhail, Albert A; Galocy, R Matthew; Shalhav, Arieh L; Zagaja, Gregory P

2007-11-01

Previous reports have suggested that a 2% to 5% device failure rate (FR) be quoted when counseling patients about robot-assisted laparoscopic radical prostatectomy (RLRP). We sought to evaluate our FR on the da Vinci system. Since February 2003, more than 800 RLRPs have been performed at our institution using a single three-armed robotic unit. A prospective database was analyzed to determine the device FR and whether it resulted in case abortion or open conversion. Intuitive Surgical Systems provided data concerning the system's performance, including its fault rate. Error messages were classified as recoverable and non-recoverable faults. Between February 2003 and November 2006, 725 RLRP cases were available for evaluation. There were no intraoperative device failures that resulted in a case conversion. Technical errors resulting in surgeon handicap occurred in 3 cases (0.4%). Four patients (0.5%) had their procedures aborted secondary to system failure at initial set-up prior to patient entrance to the operating room. Data analysis retrieved from the da Vinci console reported on a total of 807 procedures since 2003. Only 4 cases (0.4%) were reported from the Intuitive Surgical database to result in either an aborted or a converted case, which compares favorably with our results. Since the last computer system upgrade (September 2005), the mean recoverable and non-recoverable fault rates per procedure were 0.21 and 0.05, respectively. For all the advanced features the da Vinci system offers, it is surprisingly reliable. Throughout our RLRP experience, device failure resulted in case conversion, procedure abortion, and surgeon handicap in 0, 0.5%, and 0.4% of procedures, respectively. As such, a lowered device FR of 0.5% should be used when counseling patients undergoing RLRP. To avoid futile general anesthesia, a policy should be enforced to ensure that the da Vinci system is completely set up before the patient enters the operating room.

Improved Monitoring of Semi-Continuous Anaerobic Digestion of Sugarcane Waste: Effects of Increasing Organic Loading Rate on Methanogenic Community Dynamics

PubMed Central

Leite, Athaydes Francisco; Janke, Leandro; Lv, Zuopeng; Harms, Hauke; Richnow, Hans-Hermann; Nikolausz, Marcell

2015-01-01

The anaerobic digestion of filter cake and its co-digestion with bagasse, and the effect of gradual increase of the organic loading rate (OLR) from start-up to overload were investigated. Understanding the influence of environmental and technical parameters on the development of particular methanogenic pathway in the biogas process was an important aim for the prediction and prevention of process failure. The rapid accumulation of volatile organic acids at high OLR of 3.0 to 4.0 gvs·L−1·day−1 indicated strong process inhibition. Methanogenic community dynamics of the reactors was monitored by stable isotope composition of biogas and molecular biological analysis. A potential shift toward the aceticlastic methanogenesis was observed along with the OLR increase under stable reactor operating conditions. Reactor overloading and process failure were indicated by the tendency to return to a predominance of hydrogenotrophic methanogenesis with rising abundances of the orders Methanobacteriales and Methanomicrobiales and drop of the genus Methanosarcina abundance. PMID:26404240

Pyrotechnic system failures: Causes and prevention

NASA Technical Reports Server (NTRS)

Bement, Laurence J.

1988-01-01

Although pyrotechnics have successfully accomplished many critical mechanical spacecraft functions, such as ignition, severance, jettisoning and valving (excluding propulsion), failures continue to occur. Provided is a listing of 84 failures of pyrotechnic hardware with completed design over a 23-year period, compiled informally by experts from every NASA Center, as well as the Air Force Space Division and the Naval Surface Warfare Center. Analyses are presented as to when and where these failures occurred, their technical source or cause, followed by the reasons why and how these kinds of failures persist. The major contributor is a fundamental lack of understanding of the functional mechanisms of pyrotechnic devices and systems, followed by not recognizing pyrotechnics as an engineering technology, insufficient manpower with hands-on experience, too few test facilities, and inadequate guidelines and specifications for design, development, qualification and acceptance. Recommendations are made on both a managerial and technical basis to prevent failures, increase reliability, improve existing and future designs, and develop the technology to meet future requirements.

Collaboration Strategies to Reduce Technical Debt

ERIC Educational Resources Information Center

Miko, Jeffrey Allen

2017-01-01

Inadequate software development collaboration processes can allow technical debt to accumulate increasing future maintenance costs and the chance of system failures. The purpose of this qualitative case study was to explore collaboration strategies software development leaders use to reduce the amount of technical debt created by software…

Real-time attended home-polysomnography with telematic data transmission.

PubMed

Bruyneel, Marie; Van den Broecke, Sandra; Libert, Walter; Ninane, Vincent

2013-08-01

Home-polysomnography (HPSG) has been proposed as a cost-effective alternative for obstructive sleep apnea (OSA) diagnosis. We assessed, in a feasibility study, whether telematic transmission using the Dream® and Sleepbox® technologies was associated with low HPSG failure rate. Patients referred by chest physicians for clinical suspicion of OSA underwent one HPSG, using Dream® and Sleepbox® (Medatec, Belgium), which is a wireless system able to communicate with Dream®, and with Internet through a wi-fi/3G interface. It is equipped with a digital infrared camera, and with a speaker/microphone system for bidirectional audio/video communication via Skype®. The Sleep Lab nurse performed a remote discontinuous monitoring of the PSG. In case of sensor loss, she called the patient who had been previously educated to replace the sensors. Twenty-one patients have been studied. 90% of the recordings were of excellent quality. We observed a 10% PSG failure rate: one failure of the Dream®, and one recording of poor quality. There were 2 successful Skype® interventions resulting in readjustment of the defective probes (nasal cannula and EEG). PSG signal visualization was possible in 90% of cases but Skype® connection was problematic in 19% of cases. However, patients could be reached by phone to solve the problem. Real-time attended HPSG through telematic data transmission is feasible and could be an interesting perspective to decrease the failure rate of home sleep studies, even if some technical aspects need to be improved. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Portal Vein Embolization Before Liver Resection: A Systematic Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lienden, K. P. van, E-mail: k.p.vanlienden@amc.uva.nl; Esschert, J. W. van den; Graaf, W. de

2013-02-15

This is a review of literature on the indications, technique, and outcome of portal vein embolization (PVE). A systematic literature search on outcome of PVE from 1990 to 2011 was performed in Medline, Cochrane, and Embase databases. Forty-four articles were selected, including 1,791 patients with a mean age of 61 {+-} 4.1 years. Overall technical success rate was 99.3 %. The mean hypertrophy rate of the FRL after PVE was 37.9 {+-} 0.1 %. In 70 patients (3.9 %), surgery was not performed because of failure of PVE (clinical success rate 96.1 %). In 51 patients (2.8 %), the hypertrophymore » response was insufficient to perform liver resection. In the other 17 cases, 12 did not technically succeed (0.7 %) and 7 caused a complication leading to unresectability (0.4 %). In 6.1 %, resection was cancelled because of local tumor progression after PVE. Major complications were seen in 2.5 %, and the mortality rate was 0.1 %. A head-to-head comparison shows a negative effect of liver cirrhosis on hypertrophy response. The use of n-butyl cyanoacrylate seems to have a greater effect on hypertrophy, but the difference with other embolization materials did not reach statistical significance. No difference in regeneration is seen in patients with cholestasis or chemotherapy. Preoperative PVE has a high technical and clinical success rate. Liver cirrhosis has a negative effect on regeneration, but cholestasis and chemotherapy do not seem to have an influence on the hypertrophy response. The use of n-butyl cyanoacrylate may result in a greater hypertrophy response compared with other embolization materials used.« less

Mammographic density estimation with automated volumetric breast density measurement.

PubMed

Ko, Su Yeon; Kim, Eun-Kyung; Kim, Min Jung; Moon, Hee Jung

2014-01-01

To compare automated volumetric breast density measurement (VBDM) with radiologists' evaluations based on the Breast Imaging Reporting and Data System (BI-RADS), and to identify the factors associated with technical failure of VBDM. In this study, 1129 women aged 19-82 years who underwent mammography from December 2011 to January 2012 were included. Breast density evaluations by radiologists based on BI-RADS and by VBDM (Volpara Version 1.5.1) were compared. The agreement in interpreting breast density between radiologists and VBDM was determined based on four density grades (D1, D2, D3, and D4) and a binary classification of fatty (D1-2) vs. dense (D3-4) breast using kappa statistics. The association between technical failure of VBDM and patient age, total breast volume, fibroglandular tissue volume, history of partial mastectomy, the frequency of mass > 3 cm, and breast density was analyzed. The agreement between breast density evaluations by radiologists and VBDM was fair (k value = 0.26) when the four density grades (D1/D2/D3/D4) were used and moderate (k value = 0.47) for the binary classification (D1-2/D3-4). Twenty-seven women (2.4%) showed failure of VBDM. Small total breast volume, history of partial mastectomy, and high breast density were significantly associated with technical failure of VBDM (p = 0.001 to 0.015). There is fair or moderate agreement in breast density evaluation between radiologists and VBDM. Technical failure of VBDM may be related to small total breast volume, a history of partial mastectomy, and high breast density.

Comparison of two text message (mHealth) campaigns for the Deaf: Contracted out v. conducted in-house.

PubMed

Hacking, Damian; Lau, Yan Kwan; Haricharan, Hanne Jensen; Heap, Marion

2015-11-20

Cell phone-based health information (mobile health or mHealth) campaigns are an emerging technology. This evaluation focused on the aspect of cost of two health information campaigns, one on hypertension and one on pregnancy. Researchers could either contract out the technical components of the campaigns or attempt to run the campaigns themselves, in-house. The in-house campaigns cost an estimated ZAR13 548.72 v. the private provider quotes which ranged from ZAR27 542.97 to ZAR34 227.59. Running the campaigns in-house was more labour intensive and required more technical expertise, but had a reduced delivery failure rate (9.2% in-house v. 30.0% private provider). Running small to medium SMS (text message) campaigns for evaluative purposes proved advantageous over contracting out to private providers. Larger-scale evaluations and full-scale roll-out will require the services of private providers, but it is still essential that researchers actively engage with and monitor the technical aspects of these campaigns.

Alternative Techniques for Treatment of Complex Below-the Knee Arterial Occlusions in Diabetic Patients With Critical Limb Ischemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gandini, Roberto; Uccioli, Luigi; Spinelli, Alessio

The purpose of this study was to describe alternative endovascular (EV) techniques and assess their feasibility and efficacy in minimizing failure rates in limb salvage for the treatment of complex below-the knee (BTK) occlusions that could not be crossed with a conventional antegrade access. Between December 2007 and November 2010, 1,035 patients (557 male) underwent EV treatment for critical limb ischemia in our institution. In 124 (12% [83 male], mean age 68.2 {+-} 0.5 years) patients, transfemoral antegrade revascularization attempt failed, and an alternative approach was used. Follow-up was performed at 1 and 6 months. Results were compared with 56more » patients treated between November 2002 and November 2007, in whom conventional technique was unsuccessful and unconventional techniques were not adopted. Technical success was achieved in 119 (96%) patients. The limb-salvage rates were 96.8% and 83% at 1- and 6-month follow-up, respectively. Sixteen (12.9%) and 33 (26.6%) patients underwent reintervention at 1- and 6-month follow-up, respectively. Transcutaneous oxygen tension increased at 1 month (44.7 {+-} 1.1 vs. 15.7 {+-} 0.8 mmHg; p < 0.001) and remained stable at follow-up. Twenty (16.1%) patients required major amputation. Thirteen (10.4%) patients died during follow-up. In our previous experience, percutaneous transluminal angioplasty failure, amputation, and death rates were 10.9, 39.2, and 23.2%, respectively. Alternative techniques allowed a significant decrease of major amputation and death rates (p = 0.0001 and p = 0.02, respectively). The use of alternative techniques seems feasible in case of a failed antegrade BTK revascularization attempt and could minimize failure rates in the treatment of complex occlusions while providing satisfying clinical success rates at 6 months.« less

Systolic Strain Abnormalities to Predict Hospital Readmission in Patients With Heart Failure and Normal Ejection Fraction

PubMed Central

Borer, Steven M.; Kokkirala, Aravind; O'Sullivan, David M.; Silverman, David I.

2011-01-01

Background Despite intensive investigation, the pathogenesis of heart failure with normal ejection fraction (HFNEF) remains unclear. We hypothesized that subtle abnormalities of systolic function might play a role, and that abnormal systolic strain and strain rate would provide a marker for adverse outcomes. Methods Patients of new CHF and left ventricular ejection fraction > 50% were included. Exclusion criteria were recent myocardial infarction, severe valvular heart disease, severe left ventricular hypertrophy (septum >1.8 cm), or a technically insufficient echocardiogram. Average peak systolic strain and strain rate were measured using an off-line grey scale imaging technique. Systolic strain and strain rate for readmitted patients were compared with those who remained readmission-free. Results One hundred consecutive patients with a 1st admission for HFNEF from January 1, 2004 through December 31, 2007, inclusive, were analyzed. Fifty two patients were readmitted with a primary diagnosis of heart failure. Systolic strain and strain rates were reduced in both study groups compared to controls. However, systolic strain did not differ significantly between the two groups (-11.7% for those readmitted compared with -12.9% for those free from readmission, P = 0.198) and systolic strain rates also were similar (-1.05 s-1 versus -1.09 s-1, P = 0.545). E/e’ was significantly higher in readmitted patients compared with those who remained free from readmission (14.5 versus 11.0, P = 0.013). E/e’ (OR 1.189, 95% CI 1.026-1.378; P = 0.021) was found to be an independent predictor for HFNEF readmission. Conclusions Among patients with new onset HFNEF, SS and SR rates are reduced compared with patients free of HFNEF, but do not predict hospital readmission. Elevated E/e’ is a predictor of readmission in these patients. PMID:28352395

Moving International Technical Communication Forward: A World Englishes Approach

ERIC Educational Resources Information Center

Bokor, Michael Jarvis Kwadzo

2011-01-01

This article explores how the English language contributes to cross-boundary communication failure and establishes that there is an "English language problem" that has not been adequately addressed in preparing United States native English-speaking students for international technical communication tasks. For example, U.S. technical communication…

NASA Helps Keep the Light Burning for the Saturn Car Company

NASA Technical Reports Server (NTRS)

2003-01-01

The Saturn Electronics & Engineering, Inc. (Saturn) facility in Marks, Miss., that produces lamp assemblies was experiencing itermittent problems with its automotive under the hood lamps. After numerous testing and engineering efforts, technicians could not pin down the root of the problem. So Saturn contacted the NASA Technology Assistance Program (TAP) at Stennis Space Center. The Marks production facility had been experiencing intermittent problems with under the hood lamp assemblies for some time. The failure rate, at 2 percent, was unacceptable. Every effort was made to identify the problem so that corrective action could be put in place. The problem was investigated and researched by Saturn's engineering department. In addition, Saturn brought in several independent testing laboratories. Other measures included examining the switch component suppliers and auditing them for compliance to the design specifications and for surface contaminants. All attempts to identify the factors responsible for the failures were inconclusive. In an effort to get to the root of the problem, and at the recommendation of the Mississippi Department of Economic Development, Saturn contacted the NASA TAP at Stennis. The NASA Materials and Contamination Laboratory, with assistance from the Stennis Prototype Laboratory, conducted a materials evaluation study on the switch components. The laboratory findings showed the failures were caused by a build-up of carbon-based contaminants on the switch components. Saturn Electronics & Engineering, Inc., is a minority-owned provider of contract manufacturing services to a diverse global marketplace. Saturn operates manufacturing facilities globally serving the North American, European, and Asian markets. Saturn's production facility in Marks, Mississippi, produces more than 1,000,000 lamps and switches monthly. "Since the NASA recommendations were implemented, our internal failure rate for intermittency has dropped to less than .02 percent. Most importantly, we restored our high-level of customer satisfaction. Stennis provided an invaluable service to our business," Patrick said. Both NASA and Saturn were pleased with the results form this technical assistance project. The Technology Assistance Program at Stennis makes available to the public NASA technical expertise and access to lab facilities. This project provided both services with a positive outcome.

Technical complications of implant-causes and management: A comprehensive review

PubMed Central

Gupta, Swati; Gupta, Hemant; Tandan, Amrit

2015-01-01

Given the increasing popularity of dental implants, the number of failures due to late implant fracture is also expected to increase. Hence, the scope for prevention and management needs to be emphasized. The objective of this review article is to analyze the various causes of failure of dental implants due to implant fixture/abutment screw fractures and also to enumerate the management and the preventive options for these failures, thereby aiming to help the clinicians to properly plan the implant-supported prosthesis treatment by considering the important biomechanical aspects of this type of rehabilitation. The present review emphasizes the causes and management of technical complications and not the incidence of such complications. PMID:26668445

The Role of Change Agents in Technology Adoption Process

NASA Astrophysics Data System (ADS)

Gyampoh-Vidogah, Regina; Moreton, Robert

Although the total or partial failure of Information Technology (IT) projects are well documented such failures are not entirely technical in nature (Donohue et al, 2001). Project failures are often caused by lack of attention to social factors. (2002) identified ethical issues whilst (1999) and (2002) point to human factors, which in essence are the norms and culture of the implementation environment. On the. influence of culture on project success, (2003) noted that, the cultural problems are much bigger than the technical ones, adding: "The biggest hurdle is making people realise that information needs to be shared. It is only with this ethos of sharing information that take-up of technologies will be hastened." Consequently, research and debate about IT implementation is likely to continue until the development process is under better control (Nolan 1999). This state of constant evaluation is crucial because aborted IT projects are still common place. According to (1998), 31% of all corporate technology development projects resulted in cancellation. Although in broad terms, there seems to be ample evidence of the influence of non-technical factors on project failure the dynamics of how this happens is not widely discussed. There are some pointers to the dynamics of the process in literature.

Improving the retrieval rate of inferior vena cava filters with a multidisciplinary team approach.

PubMed

Inagaki, Elica; Farber, Alik; Eslami, Mohammad H; Siracuse, Jeffrey J; Rybin, Denis V; Sarosiek, Shayna; Sloan, J Mark; Kalish, Jeffrey

2016-07-01

The option to retrieve inferior vena cava (IVC) filters has resulted in an increase in the utilization of these devices as stopgap measures in patients with relative contraindications to anticoagulation. These retrievable IVC filters, however, are often not retrieved and become permanent. Recent data from our institution confirmed a historically low retrieval rate. Therefore, we hypothesized that the implementation of a new IVC filter retrieval protocol would increase the retrieval rate of appropriate IVC filters at our institution. All consecutive patients who underwent an IVC filter placement at our institution between September 2003 and July 2012 were retrospectively reviewed. In August 2012, a multidisciplinary task force was established, and a new IVC filter retrieval protocol was implemented. Prospective data were collected using a centralized interdepartmental IVC filter registry for all consecutive patients who underwent an IVC filter placement between August 2012 and September 2014. Patients were chronologically categorized into preimplementation (PRE) and postimplementation (POST) groups. Comparisons of outcome measures, including the retrieval rate of IVC filters along with rates of retrieval attempt and technical failure, were made between the two groups. In the PRE and POST groups, a total of 720 and 74 retrievable IVC filters were implanted, respectively. In the POST group, 40 of 74 filters (54%) were successfully retrieved compared with 82 of 720 filters (11%) in the PRE group (P < .001). Furthermore, a greater number of IVC filter retrievals were attempted in the POST group than in the PRE group (66% vs 14%; P < .001). No significant difference was observed between the PRE and POST groups for technical failure (17% vs 18%; P = .9). The retrieval rate of retrievable IVC filters at our institution was significantly increased with the implementation of a new IVC filter retrieval protocol with a multidisciplinary team approach. This improved retrieval rate is possible with minimal dedication of resources and can potentially lead to a decrease in IVC filter-related complications in the future. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Mammographic Density Estimation with Automated Volumetric Breast Density Measurement

PubMed Central

Ko, Su Yeon; Kim, Eun-Kyung; Kim, Min Jung

2014-01-01

Objective To compare automated volumetric breast density measurement (VBDM) with radiologists' evaluations based on the Breast Imaging Reporting and Data System (BI-RADS), and to identify the factors associated with technical failure of VBDM. Materials and Methods In this study, 1129 women aged 19-82 years who underwent mammography from December 2011 to January 2012 were included. Breast density evaluations by radiologists based on BI-RADS and by VBDM (Volpara Version 1.5.1) were compared. The agreement in interpreting breast density between radiologists and VBDM was determined based on four density grades (D1, D2, D3, and D4) and a binary classification of fatty (D1-2) vs. dense (D3-4) breast using kappa statistics. The association between technical failure of VBDM and patient age, total breast volume, fibroglandular tissue volume, history of partial mastectomy, the frequency of mass > 3 cm, and breast density was analyzed. Results The agreement between breast density evaluations by radiologists and VBDM was fair (k value = 0.26) when the four density grades (D1/D2/D3/D4) were used and moderate (k value = 0.47) for the binary classification (D1-2/D3-4). Twenty-seven women (2.4%) showed failure of VBDM. Small total breast volume, history of partial mastectomy, and high breast density were significantly associated with technical failure of VBDM (p = 0.001 to 0.015). Conclusion There is fair or moderate agreement in breast density evaluation between radiologists and VBDM. Technical failure of VBDM may be related to small total breast volume, a history of partial mastectomy, and high breast density. PMID:24843235

Endoscopic bilateral stent-in-stent placement for malignant hilar obstruction using a large cell type stent.

PubMed

Park, Jin Myung; Lee, Sang Hyub; Chung, Kwang Hyun; Jang, Dong Kee; Ryu, Ji Kon; Kim, Yong-Tae; Lee, Jae Min; Paik, Woo Hyun

2016-12-01

Bilateral stent-in-stent (SIS) self-expandable metal stent placement is technically challenging for palliation of unresectable malignant hilar obstruction. In the SIS technique, the uniform large cell type biliary stent facilitates contralateral stent deployment through the mesh of the first metallic stent. This study aimed to assess the technical success and clinical effectiveness of this technique with a uniform large cell type biliary stent. Thirty-one patients who underwent bilateral SIS placement using a large cell type stent were reviewed retrospectively. All patients showed malignant hilar obstruction (Bismuth types II, III, IV) with different etiologies. Sixteen (51.6%) patients were male. The mean age of the patients was 67.0+/-14.0 years. Most patients were diagnosed as having hilar cholangiocarcinoma (58.1%) and gallbladder cancer (29.0%). Technical success rate was 83.9%. Success was achieved more frequently in patients without masses obstructing the biliary confluence (MOC) than those with MOC (95.2% vs 60.0%, P=0.03). Functional success rate was 77.4%. Complications occurred in 29.0% of the patients. These tended to occur more frequently in patients with MOC (50.0% vs 19.0%, P=0.11). Median time to recurrent biliary obstruction was 188 days and median survival was 175 days. The large cell type stent can be used efficiently for bilateral SIS placement in malignant hilar obstruction. However, the risk of technical failure increases in patients with MOC, and caution is needed to prevent complications for these patients.

The influence of deficient retro-aortic rim on technical success and early adverse events following device closure of secundum atrial septal defects: An Analysis of the IMPACT Registry®.

PubMed

O'Byrne, Michael L; Gillespie, Matthew J; Kennedy, Kevin F; Dori, Yoav; Rome, Jonathan J; Glatz, Andrew C

2017-01-01

Concern regarding aortic erosion has focused attention on the retro-aortic rim in patients undergoing device closure of atrial septal defects (ASD), but its effect on early outcomes is not well studied. A multicenter retrospective cohort study of patients undergoing device occlusion of ASD between 1/2011-10/2014 was performed, using data from the IMproving Pediatric and Adult Congenital Treatment Registry. Subjects were divided between those with retro-aortic rim <5 and ≥5 mm. Primary outcomes were technical failure and major early adverse events. Case times were measured as surrogates of technical complexity. The effect of deficient retro-aortic rim on primary outcomes was assessed using hierarchical logistic regression, adjusting for other suspected covariates and assessing whether they represent independent risk factors RESULTS: 1,564 subjects (from 77 centers) were included, with deficient retro-aortic rim present in 40%. Technical failure occurred in 91 subjects (5.8%) and a major early adverse event in 64 subjects (4.1%). Adjusting for known covariates, the presence of a deficient retro-aortic rim was not significantly associated with technical failure (OR: 1.3, 95% CI: 0.9-2.1) or major early adverse event (OR: 0.7, 95% CI: 0.4-1. 2). Total case (P = 0.01) and fluoroscopy time (P = 0.02) were greater in subjects with deficient rim, but sheath time was not significantly different (P = 0.07). Additional covariates independently associated with these outcomes were identified. Deficient retro-aortic rim was highly prevalent but not associated with increased risk of technical failure or early adverse events. Studies with longer follow-up are necessary to assess other outcomes, including device erosion. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Performance interface document for users of Tracking and Data Relay Satellite System (TDRSS) electromechanically steered antenna systems (EMSAS)

NASA Technical Reports Server (NTRS)

Hockensmith, R.; Devine, E.; Digiacomo, M.; Hager, F.; Moss, R.

1983-01-01

Satellites that use the NASA Tracking and Data Relay Satellite System (TDRSS) require antennas that are crucial for performing and achieving reliable TDRSS link performance at the desired data rate. Technical guidelines are presented to assist the prospective TDRSS medium-and high-data rate user in selecting and procuring a viable, steerable high-gain antenna system. Topics addressed include the antenna gain/transmitter power/data rate relationship; Earth power flux-density limitations; electromechanical requirements dictated by the small beam widths, desired angular coverage, and minimal torque disturbance to the spacecraft; weight and moment considerations; mechanical, electrical and thermal interfaces; design lifetime failure modes; and handling and storage. Proven designs are cited and space-qualified assemblies and components are identified.

Retrievable Inferior Vena Cava Filters: Factors that Affect Retrieval Success

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geisbuesch, Philipp, E-mail: philippgeisbuesch@gmx.de; Benenati, James F.; Pena, Constantino S.

Purpose: To report and analyze the indications, procedural success, and complications of retrievable inferior vena cava filters (rIVCF) placement and to identify parameters that influence retrieval attempt and failure. Methods: Between January 2005 and December 2010, a total of 200 patients (80 men, median age 67 years, range 11-95 years) received a rIVCF with the clinical possibility that it could be removed. All patients with rIVCF were prospectively entered into a database and followed until retrieval or a decision not to retrieve the filter was made. A retrospective analysis of this database was performed. Results: Sixty-one percent of patients hadmore » an accepted indication for filter placement; 39% of patients had a relative indication. There was a tendency toward a higher retrieval rate in patients with relative indications (40% vs. 55%, P = 0.076). Filter placement was technically successful in all patients, with no procedure-related mortality. The retrieval rate was 53%. Patient age of >80 years (odds ratio [OR] 0.056, P > 0.0001) and presence of malignancy (OR 0.303, P = 0.003) was associated with a significantly reduced probability for attempted retrieval. Retrieval failure occurred in 7% (6 of 91) of all retrieval attempts. A time interval of > 90 days between implantation and attempted retrieval was associated with retrieval failure (OR 19.8, P = 0.009). Conclusions: Patient age >80 years and a history of malignancy are predictors of a reduced probability for retrieval attempt. The rate of retrieval failure is low and seems to be associated with a time interval of >90 days between filter placement and retrieval.« less

Denali, Tulip, and Option Inferior Vena Cava Filter Retrieval: A Single Center Experience.

PubMed

Ramaswamy, Raja S; Jun, Emily; van Beek, Darren; Mani, Naganathan; Salter, Amber; Kim, Seung K; Akinwande, Olaguoke

2018-04-01

To compare the technical success of filter retrieval in Denali, Tulip, and Option inferior vena cava filters. A retrospective analysis of Denali, Gunther Tulip, and Option IVC filters was conducted. Retrieval failure rates, fluoroscopy time, sedation time, use of advanced retrieval techniques, and filter-related complications that led to retrieval failure were recorded. There were 107 Denali, 43 Option, and 39 Tulip filters deployed and removed with average dwell times of 93.5, 86.0, and 131 days, respectively. Retrieval failure rates were 0.9% for Denali, 11.6% for Option, and 5.1% for Tulip filters (Denali vs. Option p = 0.018; Denali vs. Tulip p = 0.159; Tulip vs. Option p = 0.045). Median fluoroscopy time for filter retrieval was 3.2 min for the Denali filter, 6.75 min for the Option filter, and 4.95 min for the Tulip filter (Denali vs. Option p < 0.01; Denali vs. Tulip p < 0.01; Tulip vs. Option p = 0.67). Advanced retrieval techniques were used in 0.9% of Denali filters, 21.1% in Option filters, and 10.8% in Tulip filters (Denali vs. Option p < 0.01; Denali vs. Tulip p < 0.01; Tulip vs. Option p < 0.01). Filter retrieval failure rates were significantly higher for the Option filter when compared to both the Denali and Tulip filters. Retrieval of the Denali filter required significantly less amount of fluoroscopy time and use of advanced retrieval techniques when compared to both the Option and Tulip filters. The findings of this study indicate easier retrieval of the Denali and Tulip IVC filters when compared to the Option filter.

Is it useful to repeat an adrenal venous sampling in patients with primary hyperaldosteronism?

PubMed

Bouhanick, B; Delchier, M-C; Fauvel, J; Rousseau, H; Amar, J; Chamontin, B

2014-02-01

Adrenal venous sampling (AVS) is a challenging technical procedure and few patients had AVS procedure twice. To evaluate the reproducibility of the AVS, why AVS were repeated and the conclusions drawn from them. From 1997-2012, 12 patients underwent two AVS. A cortisol level in the adrenal vein greater than or equal to 1.1 to inferior vena cava defined a successful catheterization and a lateralization of secretion corresponded to an aldosterone-to-cortisol vein ratio greater than or equal to 2 between the one side to another. The same side of lateralization of secretion was found in 75% of them. The second AVS were due to technical failure (n=4), unproven lateralization (n=2), a lateralization opposite to the main nodule and ipsilateral to hyperplasia (n=4) on first AVS. For two patients, as the CT was normal, AVS was required again. The second AVS was successful in all patients, including those with an initial technical failure but only patient with technical failure underwent surgery, as BP and kaliemia were controlled. Lateralization on the side of hyperplasia or opposite to the biggest nodule was confirmed in two of four cases. When AVS is unsuccessful for technical reasons, it is worth doing it again but after being sure that surgery is still possibly indicated. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Stock price change rate prediction by utilizing social network activities.

PubMed

Deng, Shangkun; Mitsubuchi, Takashi; Sakurai, Akito

2014-01-01

Predicting stock price change rates for providing valuable information to investors is a challenging task. Individual participants may express their opinions in social network service (SNS) before or after their transactions in the market; we hypothesize that stock price change rate is better predicted by a function of social network service activities and technical indicators than by a function of just stock market activities. The hypothesis is tested by accuracy of predictions as well as performance of simulated trading because success or failure of prediction is better measured by profits or losses the investors gain or suffer. In this paper, we propose a hybrid model that combines multiple kernel learning (MKL) and genetic algorithm (GA). MKL is adopted to optimize the stock price change rate prediction models that are expressed in a multiple kernel linear function of different types of features extracted from different sources. GA is used to optimize the trading rules used in the simulated trading by fusing the return predictions and values of three well-known overbought and oversold technical indicators. Accumulated return and Sharpe ratio were used to test the goodness of performance of the simulated trading. Experimental results show that our proposed model performed better than other models including ones using state of the art techniques.

Stock Price Change Rate Prediction by Utilizing Social Network Activities

PubMed Central

Mitsubuchi, Takashi; Sakurai, Akito

2014-01-01

Predicting stock price change rates for providing valuable information to investors is a challenging task. Individual participants may express their opinions in social network service (SNS) before or after their transactions in the market; we hypothesize that stock price change rate is better predicted by a function of social network service activities and technical indicators than by a function of just stock market activities. The hypothesis is tested by accuracy of predictions as well as performance of simulated trading because success or failure of prediction is better measured by profits or losses the investors gain or suffer. In this paper, we propose a hybrid model that combines multiple kernel learning (MKL) and genetic algorithm (GA). MKL is adopted to optimize the stock price change rate prediction models that are expressed in a multiple kernel linear function of different types of features extracted from different sources. GA is used to optimize the trading rules used in the simulated trading by fusing the return predictions and values of three well-known overbought and oversold technical indicators. Accumulated return and Sharpe ratio were used to test the goodness of performance of the simulated trading. Experimental results show that our proposed model performed better than other models including ones using state of the art techniques. PMID:24790586

Clinical Outcomes of Self-Expandable Metal Stents for Malignant Rectal Obstruction.

PubMed

Lee, Hyun Jung; Hong, Sung Pil; Cheon, Jae Hee; Kim, Tae Il; Kim, Won Ho; Park, Soo Jung

2018-01-01

Self-expandable metal stents are widely used to treat malignant colorectal obstruction. However, data on clinical outcomes of stent placement for rectal obstruction specifically are lacking. We aimed to investigate the clinical outcomes of self-expandable metal stents in malignant rectal obstruction in comparison with those in left colonic obstruction and to identify factors associated with clinical failure and complication. This was a retrospective study. The study was conducted at a tertiary care center. Between January 2005 and December 2013, medical charts of patients who underwent stent placement for malignant rectal or left colonic obstruction were reviewed retrospectively. Study intervention included self-expandable metal stent placement. Technical success, clinical success, and complications were measured. Technical success rates for the 2 study groups (rectum vs left colon, 93.5% vs 93.1%; p = 0.86) did not differ significantly; however, the clinical success rate was lower in patients with rectal obstruction (85.4% vs 92.1%; p = 0.02). In addition, the complication rate was higher in patients with rectal obstruction (37.4% vs 25.1%; p = 0.01). Patients with rectal obstruction showed higher rates of obstruction because of extracolonic malignancy (33.8% vs 15.8%; p < 0.001) and stent use for palliation (78.6% vs 56.3%; p < 0.001). Multivariate analysis indicated obstruction attributed to extracolonic malignancy and covered stent usage to be independent risk factors for clinical failure. Factors predictive of complications in the palliative group were total obstruction, obstruction because of extracolonic malignancy, and covered stent usage. This was a retrospective, single-center study. The efficacy and safety of stent placement for malignant rectal obstruction were comparable with those for left colonic obstruction. However, obstruction attributed to extracolonic malignancy, use of covered stents, and total obstruction negatively impacted clinical outcomes of self-expandable metal stent placement and must be considered by endoscopists. See Video Abstract at http://links.lww.com/DCR/A417.

Qualification Testing Versus Quantitative Reliability Testing of PV - Gaining Confidence in a Rapidly Changing Technology: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurtz, Sarah; Repins, Ingrid L; Hacke, Peter L

Continued growth of PV system deployment would be enhanced by quantitative, low-uncertainty predictions of the degradation and failure rates of PV modules and systems. The intended product lifetime (decades) far exceeds the product development cycle (months), limiting our ability to reduce the uncertainty of the predictions for this rapidly changing technology. Yet, business decisions (setting insurance rates, analyzing return on investment, etc.) require quantitative risk assessment. Moving toward more quantitative assessments requires consideration of many factors, including the intended application, consequence of a possible failure, variability in the manufacturing, installation, and operation, as well as uncertainty in the measured accelerationmore » factors, which provide the basis for predictions based on accelerated tests. As the industry matures, it is useful to periodically assess the overall strategy for standards development and prioritization of research to provide a technical basis both for the standards and the analysis related to the application of those. To this end, this paper suggests a tiered approach to creating risk assessments. Recent and planned potential improvements in international standards are also summarized.« less

Long-Term Pancreas Allograft Survival in Simultaneous Pancreas-Kidney Transplantation by Era

PubMed Central

Waki, Kayo; Terasaki, Paul I.; Kadowaki, Takashi

2010-01-01

OBJECTIVE To determine whether short-term improvement in pancreas graft survival with simultaneous pancreas-kidney (SPK) transplants translated into improved long-term survival, then to examine the implications of that determination. RESEARCH DESIGN AND METHODS We analyzed data for 14,311 diabetic patients who received a first SPK transplant between October 1987 and November 2007, using Kaplan-Meier analysis for graft survival rates and Cox regression analysis for year-of-transplant effect. RESULTS Overall, from 1995 to 2004, 5-year pancreas graft survival stayed about the same (70–71%). Limiting analysis to grafts that survived more than 1 year, 5-year survival from 1987 to 2004 ranged from 80 to 84%. With 1987–1989 as reference, the adjusted hazard ratio for graft failure by year of transplant increased to 1.49 (95% CI 0.97–2.30) in 2000–2004. CONCLUSIONS Long-term pancreas graft survival has remained unchanged despite the dramatic decreases in technical failures and early acute rejection rates that have contributed to prolonged SPK graft survival. PMID:20460444

Refurbishment of Railroad Crossties : A Technical and Economic Analysis

DOT National Transportation Integrated Search

1977-12-01

An analysis of the principal modes of failure for wooden railroad crossties was conducted and an evaluation of the technical and economic feasibility of refurbishing these ties was conducted. Among the principal modes of structural deterioration, onl...

Small sample estimation of the reliability function for technical products

NASA Astrophysics Data System (ADS)

Lyamets, L. L.; Yakimenko, I. V.; Kanishchev, O. A.; Bliznyuk, O. A.

2017-12-01

It is demonstrated that, in the absence of big statistic samples obtained as a result of testing complex technical products for failure, statistic estimation of the reliability function of initial elements can be made by the moments method. A formal description of the moments method is given and its advantages in the analysis of small censored samples are discussed. A modified algorithm is proposed for the implementation of the moments method with the use of only the moments at which the failures of initial elements occur.

Adrenal vein sampling: substantial need for technical improvement at regional referral centres.

PubMed

Elliott, Panda; Holmes, Daniel T

2013-10-01

Adrenal vein sampling (AVS) is the gold standard for localization of aldosterone producing adenoma. The anatomy of the right adrenal vein makes this procedure technically demanding and it may yield no clinical information if the adrenal veins are not adequately cannulated. Having frequently observed the technical failure of AVS, we undertook a review of 220 procedures in British Columbia, Canada. Subjects were retrospectively identified through the laboratory information system. The following were collected: demographics, screening aldosterone concentration and renin activity/mass, results of dynamic function tests, AVS aldosterone and cortisol results. Standard calculations were performed on AVS data and site-specific success rates were compared. The effect of adrenocorticotropin hormone (ACTH) stimulation on the selectivity index (SI) and lateralization index (LI) were explored. The overall technical success-rate of AVS procedures was only 44% in procedures where no ACTH-stimulation was used (n=200) but this rose significantly (p<0.01) to 82% for those employing ACTH (n=139). ACTH-stimulation significantly increased the median SI (left: 5.8 vs 36.7, p<0.01; right: 7.0 vs 51.2, p<0.01), and salvaged 36 procedures from yielding no information, 21 of which demonstrated lateralization of aldosterone production. In 64 cases showing lateralization both pre and post-stimulation, ACTH significantly decreased the median LI from 5.4 to 2.2, p<0.01, creating substantial risk for spurious loss of lateralization. The technical success of AVS is lower than reported elsewhere. Provided that effects on the LI are considered, the use of ACTH-stimulation during AVS assists in the identification of unilateral forms of PA. Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Lower extremity computed tomography angiography can help predict technical success of endovascular revascularization in the superficial femoral and popliteal artery.

PubMed

Itoga, Nathan K; Kim, Tanner; Sailer, Anna M; Fleischmann, Dominik; Mell, Matthew W

2017-09-01

Preprocedural computed tomography angiography (CTA) assists in evaluating vascular morphology and disease distribution and in treatment planning for patients with lower extremity peripheral artery disease (PAD). The aim of the study was to determine the predictive value of radiographic findings on CTA and technical success of endovascular revascularization of occlusions in the superficial femoral artery-popliteal (SFA-pop) region. Medical records and available imaging studies were reviewed for patients undergoing endovascular intervention for PAD between January 2013 and December 2015 at a single academic institution. Radiologists reviewed preoperative CTA scans of patients with occlusions in the SFA-pop region. Radiographic criteria previously used to evaluate chronic occlusions in the coronary arteries were used. Technical success, defined as restoration of inline flow through the SFA-pop region with <30% stenosis at the end of the procedure, and intraoperative details were evaluated. From 2013 to 2015, there were 407 patients who underwent 540 endovascular procedures for PAD. Preprocedural CTA scans were performed in 217 patients (53.3%), and 84 occlusions in the SFA-pop region were diagnosed. Ten occlusions were excluded as no endovascular attempt to cross the lesion was made because of extensive disease or concomitant iliac intervention. Of the remaining 74 occlusions in the SFA-pop region, 59 were successfully treated (80%) and 15 were unsuccessfully crossed (20%). The indications for revascularization were claudication in 57% of patients and critical limb ischemia in the remaining patients. TransAtlantic Inter-Society Consensus A, B, and C occlusions were treated with 87% success, whereas D occlusions were treated with 68% success (P = .047). There were nine occlusions with 100% vessel calcification that was associated with technical failure (P = .014). Longer lengths of occlusion were also associated with technical failure (P = .042). Multiple occlusions (P = .55), negative remodeling (P = .69), vessel runoff (P = .56), and percentage of vessel calcification (P = .059) were not associated with failure. On multivariable analysis, 100% calcification remained the only significant predictor of technical failure (odds ratio, 9.0; 95% confidence interval, 1.8-45.8; P = .008). Analysis of preoperative CTA shows 100% calcification as the best predictor of technical failure of endovascular revascularization of occlusions in the SFA-pop region. Further studies are needed to determine the cost-effectiveness of obtaining preoperative CTA for lower extremity PAD. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Clinical survival of indirect, anterior 3-unit surface-retained fibre-reinforced composite fixed dental prosthesis: Up to 7.5-years follow-up.

PubMed

Kumbuloglu, Ovul; Özcan, Mutlu

2015-06-01

This prospective clinical study evaluated the performance of indirect, anterior, surface-retained, fibre-reinforced-composite restorations (ISFRCR). Between June-2003 and January-2011, a total of 134 patients (83 females, 51 males, 16-68 years old) received 175 ISFRCRs (local ethical registration number: 14/9/4). All restorations were made indirectly on a plaster model using unidirectional E-glass fibres (everStick C&B, StickTech) in combination with a laboratory resin composite (Dialogue, Schütz Dental) and cemented according to the instructions of 4 resin cements [(RelyX ARC, 3M-ESPE, n=61), Bifix DC, VOCO, n=45), Variolink II (Ivoclar Vivadent, n=32) and Multilink (Ivoclar Vivadent, n=37)]. After baseline recordings, patients were followed at 6 months and thereafter annually up to 7.5 years. The evaluation protocol involved technical (chipping, debonding or fracture of tooth/restoration) and biological failures (caries). Mean observation period was 58 months. Altogether, 13 failures were observed [survival rate: 97.7%] (Kaplan-Meier). One catastrophic fracture [(cement: RelyX ARC), eight partial debonding (cement: Bifix DC (5), Multilink (1), RelyX ARC (1), Variolink II (1)] and four delaminations of veneering composite [(cement: Bifix DC (2), RelyX ARC (1), Multilink (1)] were observed. Except one replacement, all defective restorations were repaired or recemented. Annual failure rate of ISFRCRs was 1.73%. The survival rates with the four resin cements did not show significant differences (RelyX ARC: 98.3%; Bifix DC: 93.5%; Variolink 2: 100%; Multilink: 100%) (p=0.114). Secondary caries did not occur in any of the teeth. The 3-unit anterior indirect surface-retained resin-bonded FRC FDPs showed similar clinical survival rate when cemented with the resin cements tested. Experienced failures in general were due to debonding of the restoration or delamination of the veneering composite. 3-unit surface retained resin-bonded FRC FDPs could be considered minimal invasive and cost-effective alternatives to conventional tooth- or implant-borne FDPs. Failures were mainly repairable in the form of chipping or debonding depending on the resin cement type. Copyright © 2015 Elsevier Ltd. All rights reserved.

Management of Transjugular Intrahepatic Portosystemic Shunt (TIPS)-associated Refractory Hepatic Encephalopathy by Shunt Reduction Using the Parallel Technique: Outcomes of a Retrospective Case Series

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cookson, Daniel T., E-mail: danielthomascookson@yahoo.co.uk; Zaman, Zubayr; Gordon-Smith, James

2011-02-15

Purpose: To investigate the reproducibility and technical and clinical success of the parallel technique of transjugular intrahepatic portosystemic shunt (TIPS) reduction in the management of refractory hepatic encephalopathy (HE). Materials and Methods: A 10-mm-diameter self-expanding stent graft and a 5-6-mm-diameter balloon-expandable stent were placed in parallel inside the existing TIPS in 8 patients via a dual unilateral transjugular approach. Changes in portosystemic pressure gradient and HE grade were used as primary end points. Results: TIPS reduction was technically successful in all patients. Mean {+-} standard deviation portosystemic pressure gradient before and after shunt reduction was 4.9 {+-} 3.6 mmHg (range,more » 0-12 mmHg) and 10.5 {+-} 3.9 mmHg (range, 6-18 mmHg). Duration of follow-up was 137 {+-} 117.8 days (range, 18-326 days). Clinical improvement of HE occurred in 5 patients (62.5%) with resolution of HE in 4 patients (50%). Single episodes of recurrent gastrointestinal hemorrhage occurred in 3 patients (37.5%). These were self-limiting in 2 cases and successfully managed in 1 case by correction of coagulopathy and blood transfusion. Two of these patients (25%) died, one each of renal failure and hepatorenal failure. Conclusion: The parallel technique of TIPS reduction is reproducible and has a high technical success rate. A dual unilateral transjugular approach is advantageous when performing this procedure. The parallel technique allows repeat bidirectional TIPS adjustment and may be of significant clinical benefit in the management of refractory HE.« less

Report of the Odyssey FPGA Independent Assessment Team

NASA Technical Reports Server (NTRS)

Mayer, Donald C.; Katz, Richard B.; Osborn, Jon V.; Soden, Jerry M.; Barto, R.; Day, John H. (Technical Monitor)

2001-01-01

An independent assessment team (IAT) was formed and met on April 2, 2001, at Lockheed Martin in Denver, Colorado, to aid in understanding a technical issue for the Mars Odyssey spacecraft scheduled for launch on April 7, 2001. An RP1280A field-programmable gate array (FPGA) from a lot of parts common to the SIRTF, Odyssey, and Genesis missions had failed on a SIRTF printed circuit board. A second FPGA from an earlier Odyssey circuit board was also known to have failed and was also included in the analysis by the IAT. Observations indicated an abnormally high failure rate for flight RP1280A devices (the first flight lot produced using this flow) at Lockheed Martin and the causes of these failures were not determined. Standard failure analysis techniques were applied to these parts, however, additional diagnostic techniques unique for devices of this class were not used, and the parts were prematurely submitted to a destructive physical analysis, making a determination of the root cause of failure difficult. Any of several potential failure scenarios may have caused these failures, including electrostatic discharge, electrical overstress, manufacturing defects, board design errors, board manufacturing errors, FPGA design errors, or programmer errors. Several of these mechanisms would have relatively benign consequences for disposition of the parts currently installed on boards in the Odyssey spacecraft if established as the root cause of failure. However, other potential failure mechanisms could have more dire consequences. As there is no simple way to determine the likely failure mechanisms with reasonable confidence before Odyssey launch, it is not possible for the IAT to recommend a disposition for the other parts on boards in the Odyssey spacecraft based on sound engineering principles.

76 FR 5494 - Pipeline Safety: Mechanical Fitting Failure Reporting Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-01

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part... Safety: Mechanical Fitting Failure Reporting Requirements AGENCY: Pipeline and Hazardous Materials Safety... tightening. A widely accepted industry guidance document, Gas Pipeline Technical Committee (GPTC) Guide, does...

Investigation of elastomeric bearing pad failures in Louisiana bridges : technical summary.

DOT National Transportation Integrated Search

1999-06-01

The research was to investigate DOTD's neoprene bearing pad slippage problem in order to determine the cause of problem for existing bridges and bridge characteristics where bearing pad failure has occurred. The research also was to recommend modific...

Ethical and Professional Issues in Career Assessment on the Internet.

ERIC Educational Resources Information Center

Barak, Azy

2003-01-01

Concerns about Internet-based career assessments include the following: users' technical skill level, lack of screening, psychological factors, cultural bias, unprotected results, technical failures, lack of standardization, digital divide, interpretation problems, outdated tests, copyright violations, administrator qualifications, and hidden…

Factors associated with treatment failure, dropout, and death in a cohort of tuberculosis patients in Recife, Pernambuco State, Brazil.

PubMed

de Albuquerque, Maria de Fátima Pessoa Militão; Ximenes, Ricardo Arraes de Alencar; Lucena-Silva, Norma; de Souza, Wayner Vieira; Dantas, Andréa Tavares; Dantas, Odimariles Maria Souza; Rodrigues, Laura Cunha

2007-07-01

A cohort of cases initiating tuberculosis treatment from May 2001 to July 2003 was followed in Recife, Pernambuco State, Brazil, to investigate biological, clinical, social, lifestyle, and healthcare access factors associated with three negative tuberculosis treatment outcomes (treatment failure, dropout, and death) separately and as a group. Treatment failure was associated with treatment delay, illiteracy, and alcohol consumption. Factors associated with dropout were age, prior TB treatment, and illiteracy. Death was associated with age, treatment delay, HIV co-infection, and head of family's income. Main factors associated with negative treatment outcomes as a whole were age, HIV co-infection, illiteracy, alcoholism, and prior TB treatment. We suggest the following strategies to increase cure rates: further training of the Family Health Program personnel in TB control, awareness-raising on the need to tailor their activities to special care for cases (e.g., literacy training); targeting use of directly observed therapy for higher risk groups; establishment of a flexible referral scheme to handle technical and psychosocial problems, including alcoholism; and increased collaboration with the HIV/AIDS program.

Examination of Faculty Expectations of Technical College Administrators as an Important Factor in High Performing Environments

ERIC Educational Resources Information Center

Dupuis, Phyllis A.

2009-01-01

Popular thought supports the notion that faculty expectations of technical college administrators appear to be linked to the success or failure of an institution at accomplishing its mission. These expectations provide the basis for the development of relationships that foster the growth of technical training and thus the growth of a skilled…

Fusion Safety Program annual report, fiscal year 1994

NASA Astrophysics Data System (ADS)

Longhurst, Glen R.; Cadwallader, Lee C.; Dolan, Thomas J.; Herring, J. Stephen; McCarthy, Kathryn A.; Merrill, Brad J.; Motloch, Chester C.; Petti, David A.

1995-03-01

This report summarizes the major activities of the Fusion Safety Program in fiscal year 1994. The Idaho National Engineering Laboratory (INEL) is the designated lead laboratory and Lockheed Idaho Technologies Company is the prime contractor for this program. The Fusion Safety Program was initiated in 1979. Activities are conducted at the INEL, at other DOE laboratories, and at other institutions, including the University of Wisconsin. The technical areas covered in this report include tritium safety, beryllium safety, chemical reactions and activation product release, safety aspects of fusion magnet systems, plasma disruptions, risk assessment failure rate data base development, and thermalhydraulics code development and their application to fusion safety issues. Much of this work has been done in support of the International Thermonuclear Experimental Reactor (ITER). Also included in the report are summaries of the safety and environmental studies performed by the Fusion Safety Program for the Tokamak Physics Experiment and the Tokamak Fusion Test Reactor and of the technical support for commercial fusion facility conceptual design studies. A major activity this year has been work to develop a DOE Technical Standard for the safety of fusion test facilities.

Ultrasound-Guided Angioplasty of Dysfunctional Vascular Access for Haemodialysis. The Pros and Cons

DOE Office of Scientific and Technical Information (OSTI.GOV)

García-Medina, J., E-mail: josegmedina57@gmail.com; García-Alfonso, J. J., E-mail: juanjozarandieta@gmail.com

PurposeTo describe the benefits and the disadvantages of angioplasty in dialysis fistulas using only ultrasound guidance.Materials and MethodsThis is a prospective study in 132 failing or non-maturing arteriovenous accesses that underwent 189 ultrasound-guided balloon angioplasties. The technical success was defined as non-use of X-ray fluoroscopy during the procedure.Results127 procedures (67%) were successfully completed without fluoroscopy. Most failures were due to difficulty to traverse aneurismal segments, as well as anastomotic stenoses. Including initial failures, the primary patency rates at 6, 12 months and 2 years were 75 ± 3, 41 ± 3 and 14 ± 2%, respectively.ConclusionEndovascular repair of the dysfunctional vascular access for haemodialysis under ultrasound guidance ismore » feasible and safe in roughly two-thirds of cases.« less

Revised Risk Priority Number in Failure Mode and Effects Analysis Model from the Perspective of Healthcare System

PubMed Central

Rezaei, Fatemeh; Yarmohammadian, Mohmmad H.; Haghshenas, Abbas; Fallah, Ali; Ferdosi, Masoud

2018-01-01

Background: Methodology of Failure Mode and Effects Analysis (FMEA) is known as an important risk assessment tool and accreditation requirement by many organizations. For prioritizing failures, the index of “risk priority number (RPN)” is used, especially for its ease and subjective evaluations of occurrence, the severity and the detectability of each failure. In this study, we have tried to apply FMEA model more compatible with health-care systems by redefining RPN index to be closer to reality. Methods: We used a quantitative and qualitative approach in this research. In the qualitative domain, focused groups discussion was used to collect data. A quantitative approach was used to calculate RPN score. Results: We have studied patient's journey in surgery ward from holding area to the operating room. The highest priority failures determined based on (1) defining inclusion criteria as severity of incident (clinical effect, claim consequence, waste of time and financial loss), occurrence of incident (time - unit occurrence and degree of exposure to risk) and preventability (degree of preventability and defensive barriers) then, (2) risks priority criteria quantified by using RPN index (361 for the highest rate failure). The ability of improved RPN scores reassessed by root cause analysis showed some variations. Conclusions: We concluded that standard criteria should be developed inconsistent with clinical linguistic and special scientific fields. Therefore, cooperation and partnership of technical and clinical groups are necessary to modify these models. PMID:29441184

Impact Testing of Aluminum 2024 and Titanium 6Al-4V for Material Model Development

NASA Technical Reports Server (NTRS)

Pereira, J. Michael; Revilock, Duane M.; Lerch, Bradley A.; Ruggeri, Charles R.

2013-01-01

One of the difficulties with developing and verifying accurate impact models is that parameters such as high strain rate material properties, failure modes, static properties, and impact test measurements are often obtained from a variety of different sources using different materials, with little control over consistency among the different sources. In addition there is often a lack of quantitative measurements in impact tests to which the models can be compared. To alleviate some of these problems, a project is underway to develop a consistent set of material property, impact test data and failure analysis for a variety of aircraft materials that can be used to develop improved impact failure and deformation models. This project is jointly funded by the NASA Glenn Research Center and the FAA William J. Hughes Technical Center. Unique features of this set of data are that all material property data and impact test data are obtained using identical material, the test methods and procedures are extensively documented and all of the raw data is available. Four parallel efforts are currently underway: Measurement of material deformation and failure response over a wide range of strain rates and temperatures and failure analysis of material property specimens and impact test articles conducted by The Ohio State University; development of improved numerical modeling techniques for deformation and failure conducted by The George Washington University; impact testing of flat panels and substructures conducted by NASA Glenn Research Center. This report describes impact testing which has been done on aluminum (Al) 2024 and titanium (Ti) 6Al-4vanadium (V) sheet and plate samples of different thicknesses and with different types of projectiles, one a regular cylinder and one with a more complex geometry incorporating features representative of a jet engine fan blade. Data from this testing will be used in validating material models developed under this program. The material tests and the material models developed in this program will be published in separate reports.

Follow-up of negative MRI-targeted prostate biopsies: when are we missing cancer?

PubMed

Gold, Samuel A; Hale, Graham R; Bloom, Jonathan B; Smith, Clayton P; Rayn, Kareem N; Valera, Vladimir; Wood, Bradford J; Choyke, Peter L; Turkbey, Baris; Pinto, Peter A

2018-05-21

Multiparametric magnetic resonance imaging (mpMRI) has improved clinicians' ability to detect clinically significant prostate cancer (csPCa). Combining or fusing these images with the real-time imaging of transrectal ultrasound (TRUS) allows urologists to better sample lesions with a targeted biopsy (Tbx) leading to the detection of greater rates of csPCa and decreased rates of low-risk PCa. In this review, we evaluate the technical aspects of the mpMRI-guided Tbx procedure to identify possible sources of error and provide clinical context to a negative Tbx. A literature search was conducted of possible reasons for false-negative TBx. This includes discussion on false-positive mpMRI findings, termed "PCa mimics," that may incorrectly suggest high likelihood of csPCa as well as errors during Tbx resulting in inexact image fusion or biopsy needle placement. Despite the strong negative predictive value associated with Tbx, concerns of missed disease often remain, especially with MR-visible lesions. This raises questions about what to do next after a negative Tbx result. Potential sources of error can arise from each step in the targeted biopsy process ranging from "PCa mimics" or technical errors during mpMRI acquisition to failure to properly register MRI and TRUS images on a fusion biopsy platform to technical or anatomic limits on needle placement accuracy. A better understanding of these potential pitfalls in the mpMRI-guided Tbx procedure will aid interpretation of a negative Tbx, identify areas for improving technical proficiency, and improve both physician understanding of negative Tbx and patient-management options.

A new global and comprehensive model for ICU ventilator performances evaluation.

PubMed

Marjanovic, Nicolas S; De Simone, Agathe; Jegou, Guillaume; L'Her, Erwan

2017-12-01

This study aimed to provide a new global and comprehensive evaluation of recent ICU ventilators taking into account both technical performances and ergonomics. Six recent ICU ventilators were evaluated. Technical performances were assessed under two FIO 2 levels (100%, 50%), three respiratory mechanics combinations (Normal: compliance [C] = 70 mL cmH 2 O -1 /resistance [R] = 5 cmH 2 O L -1  s -1 ; Restrictive: C = 30/R = 10; Obstructive: C = 120/R = 20), four exponential levels of leaks (from 0 to 12.5 L min -1 ) and three levels of inspiratory effort (P0.1 = 2, 4 and 8 cmH 2 O), using an automated test lung. Ergonomics were evaluated by 20 ICU physicians using a global and comprehensive model involving physiological response to stress measurements (heart rate, respiratory rate, tidal volume variability and eye tracking), psycho-cognitive scales (SUS and NASA-TLX) and objective tasks completion. Few differences in terms of technical performance were observed between devices. Non-invasive ventilation modes had a huge influence on asynchrony occurrence. Using our global model, either objective tasks completion, psycho-cognitive scales and/or physiological measurements were able to depict significant differences in terms of devices' usability. The level of failure that was observed with some devices depicted the lack of adaptation of device's development to end users' requests. Despite similar technical performance, some ICU ventilators exhibit low ergonomics performance and a high risk of misusage.

Latest technologic and surgical developments in using InterStim Therapy for sacral neuromodulation: impact on treatment success and safety.

PubMed

Spinelli, Michele; Sievert, Karl-Dietrich

2008-12-01

This article accompanies a "surgery in motion" DVD on sacral neuromodulation (SNM) with InterStim Therapy, which visualizes the implantation of the InterStim II system. The article describes the technical and surgical developments of SNM and their impact on treatment success, safety, and patient's quality of life (QoL). Relevant literature on SNM with regard to technical changes and related clinical outcomes has been reviewed. Since its introduction in the early 1990s, SNM has proven useful in the treatment of several types of chronic urinary (and bowel) dysfunction. Recent technical improvements in devices and, in particular, the introduction of the tined lead 5 yr ago made SNM progress from an elaborate, open-surgery, general anesthesia, one-stage implant procedure to a minimally invasive, local anesthesia, percutaneous technique in two stages. The permanent tined lead implant enables a longer patient testing period (minimum of 14 d recommended) and less lead migration. This has considerably reduced technical failures and improved the success rate of the test phase; the response rate was almost doubled to approximately 80%. These improvements also affected tolerability, resulting in increased QoL for the patient. The use of the recently introduced smaller implantable neurostimulator InterStim II seems to further improve patient comfort and makes the implant procedure for the physician easier and shorter. However, this must be further addressed in clinical studies. SNM with InterStim Therapy using the tined lead offers an efficient treatment modality for patients in whom conservative treatment has failed.

[Infectious peritonitis in peritoneal dialysis: an over-emphasized complication].

PubMed

Vakilzadeh, N; Burnier, M; Halabi, G

2013-02-27

Peritoneal dialysis is an extrarenal epuration modality which uses physiological properties of peritoneum as a dialysis membrane. Despite the improvement of peritoneal dialysis techniques in the last ten years, peritonitis remains one of the most redoubt complications. Peritonitis may sometimes lead to technical failures, which need catheter removing, but rarely lead to death. Our retrospective study at the dialysis center of CHUV has analyzed factors which can predict this kind of complication. It calculates peritonitis rate and median peritonitis free-survival for different groups of patients. It also describes causatives organisms and their sensitivity to antibiotics.

Pancreas Transplantation for Patients with Type 1 and Type 2 Diabetes Mellitus in the United States: A Registry Report.

PubMed

Gruessner, Angelika C; Gruessner, Rainer W G

2018-06-01

Successful pancreas transplantation is still the only method to restore short-term and long-term insulin independence and good metabolic control for patients with diabetes. Since the first transplant in 1966, tremendous progress in outcome was made; however, transplant numbers have declined since 2004. This article describes the development and risk factors of pancreas transplantation with or without a kidney graft between 2001 and 2016. Patient survival and graft function improved significantly owing to careful recipient and donor selection, which reduced technical failure and immunologic graft loss rates. Published by Elsevier Inc.

Patterns of technical error among surgical malpractice claims: an analysis of strategies to prevent injury to surgical patients.

PubMed

Regenbogen, Scott E; Greenberg, Caprice C; Studdert, David M; Lipsitz, Stuart R; Zinner, Michael J; Gawande, Atul A

2007-11-01

To identify the most prevalent patterns of technical errors in surgery, and evaluate commonly recommended interventions in light of these patterns. The majority of surgical adverse events involve technical errors, but little is known about the nature and causes of these events. We examined characteristics of technical errors and common contributing factors among closed surgical malpractice claims. Surgeon reviewers analyzed 444 randomly sampled surgical malpractice claims from four liability insurers. Among 258 claims in which injuries due to error were detected, 52% (n = 133) involved technical errors. These technical errors were further analyzed with a structured review instrument designed by qualitative content analysis. Forty-nine percent of the technical errors caused permanent disability; an additional 16% resulted in death. Two-thirds (65%) of the technical errors were linked to manual error, 9% to errors in judgment, and 26% to both manual and judgment error. A minority of technical errors involved advanced procedures requiring special training ("index operations"; 16%), surgeons inexperienced with the task (14%), or poorly supervised residents (9%). The majority involved experienced surgeons (73%), and occurred in routine, rather than index, operations (84%). Patient-related complexities-including emergencies, difficult or unexpected anatomy, and previous surgery-contributed to 61% of technical errors, and technology or systems failures contributed to 21%. Most technical errors occur in routine operations with experienced surgeons, under conditions of increased patient complexity or systems failure. Commonly recommended interventions, including restricting high-complexity operations to experienced surgeons, additional training for inexperienced surgeons, and stricter supervision of trainees, are likely to address only a minority of technical errors. Surgical safety research should instead focus on improving decision-making and performance in routine operations for complex patients and circumstances.

Phase 2 Study of Docetaxel, Cisplatin, and Concurrent Radiation for Technically Resectable Stage III-IV Squamous Cell Carcinoma of the Head and Neck

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inohara, Hidenori, E-mail: hinohara@ent.med.osaka-u.ac.jp; Takenaka, Yukinori; Yoshii, Tadashi

2015-04-01

Purpose: We investigated the efficacy and safety of weekly low-dose docetaxel and cisplatin therapy concurrent with conventionally fractionated radiation in patients with technically resectable stage III-IV squamous cell carcinoma of the head and neck. Methods and Materials: Between March 2004 and October 2011, we enrolled 117 patients, of whom 116 were analyzable (43 had oropharyngeal cancer, 54 had hypopharyngeal cancer, and 19 had laryngeal cancer), and 85 (73%) had stage IV disease. Radiation consisted of 66 Gy in 33 fractions. Docetaxel, 10 mg/m{sup 2}, followed by cisplatin, 20 mg/m{sup 2}, administered on the same day were given once a week for 6 cycles.more » The primary endpoint was overall complete response (CR) rate after chemoradiation therapy. Human papillomavirus (HPV) DNA in oropharyngeal cancer was examined by PCR. Results: Of 116 patients, 82 (71%) completed treatment per protocol; 102 (88%) received the full radiation therapy dose; and 90 (78%) and 12 (10%) patients received 6 and 5 chemotherapy cycles, respectively. Overall CR rate was 71%. After median follow-up of 50.9 months (range: 15.6-113.9 months for surviving patients), 2-year and 4-year overall survival rates were 82% and 68%, respectively. Cumulative 2-year and 4-year local failure rates were 27% and 28%, respectively, whereas distant metastasis rates were 15% and 22%, respectively. HPV status in oropharyngeal cancer was not associated with treatment efficacy. Acute toxicity included grade 3 and 4 in-field mucositis in 73% and 5% of patients, respectively, whereas myelosuppression and renal injury were minimal. No patients died of toxicity. Feeding tube dependence in 8% and tracheostomy in 1% of patients were evident at 2 years postchemoradiation therapy in patients who survived without local treatment failure. Conclusions: Local control and survival with this regimen were satisfactory. Although acute toxicity, such as mucositis, was common, late toxicity, such as laryngoesophageal dysfunction, was minimal. Therapy using weekly low-dose docetaxel and cisplatin concurrent with radiation warrants further evaluation.« less

Probabilistic pipe fracture evaluations for leak-rate-detection applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rahman, S.; Ghadiali, N.; Paul, D.

1995-04-01

Regulatory Guide 1.45, {open_quotes}Reactor Coolant Pressure Boundary Leakage Detection Systems,{close_quotes} was published by the U.S. Nuclear Regulatory Commission (NRC) in May 1973, and provides guidance on leak detection methods and system requirements for Light Water Reactors. Additionally, leak detection limits are specified in plant Technical Specifications and are different for Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). These leak detection limits are also used in leak-before-break evaluations performed in accordance with Draft Standard Review Plan, Section 3.6.3, {open_quotes}Leak Before Break Evaluation Procedures{close_quotes} where a margin of 10 on the leak detection limit is used in determining the crackmore » size considered in subsequent fracture analyses. This study was requested by the NRC to: (1) evaluate the conditional failure probability for BWR and PWR piping for pipes that were leaking at the allowable leak detection limit, and (2) evaluate the margin of 10 to determine if it was unnecessarily large. A probabilistic approach was undertaken to conduct fracture evaluations of circumferentially cracked pipes for leak-rate-detection applications. Sixteen nuclear piping systems in BWR and PWR plants were analyzed to evaluate conditional failure probability and effects of crack-morphology variability on the current margins used in leak rate detection for leak-before-break.« less

Quality assurance in ultrasound screening for hepatocellular carcinoma using a standardized phantom and standard clinical images: a 3-year national investigation in Korea.

PubMed

Choi, Joon-Il; Jung, Seung Eun; Kim, Pyo Nyun; Cha, Sang Hoon; Jun, Jae Kwan; Lee, Hoo-Yeon; Park, Eun-Cheol

2014-06-01

The purpose of this study was to investigate the quality of ultrasound (US) imaging for hepatocellular carcinoma screening. The investigation was performed at all medical institutes participating in the National Cancer Screening Program in Korea. For assessment of personnel, we inquired who was performing the US screenings. For phantom image evaluation, the dead zone, vertical and horizontal measurements, axial and lateral resolution, sensitivity, and gray scale/dynamic range were evaluated. For clinical image evaluation, US images of patients were evaluated in terms of the standard images, technical information, overall image quality, appropriateness of depth, foci, annotations, and the presence of any artifacts. Failure rates for phantom and clinical image evaluations at general hospitals, smaller hospitals, and private clinics were 20.9%, 24.5%, 24.1% and 5.5%, and 14.8% and 9.5%, respectively. No statistically significant difference was observed in the failure rates for the phantom images among groups of different years of manufacture. For the clinical image evaluation, the results of radiologists were significantly better than those of other professional groups (P = .0001 and .0004 versus nonradiology physicians and nonphysicians, respectively). The failure rate was also higher when the storage format was analog versus digital (P < .001). Approximately 20% of US scanners failed the phantom image evaluation. The year of scanner manufacture was not significantly associated with the results of the phantom image evaluation. The quality of the clinical images obtained by radiologists was the best. © 2014 by the American Institute of Ultrasound in Medicine.

Imaging and transcatheter arterial embolization for traumatic splenic injuries: review of the literature.

PubMed

Raikhlin, Antony; Baerlocher, Mark Otto; Asch, Murray R; Myers, Andy

2008-12-01

The spleen is the most commonly injured visceral organ in blunt abdominal trauma in both adults and children. Nonoperative management is the current standard of practice for patients who are hemodynamically stable. However, simple observation alone has been reported to have a failure rate as high as 34%; the rate is even higher among patients with high-grade splenic injuries (American Association for the Surgery of Trauma [AAST] grade III-V). Over the past decade, angiography with transcatheter splenic artery embolization, an alternative nonoperative treatment for splenic injuries, has increased splenic salvage rates to as high as 97%. With the help of splenic artery embolization, success rates of more than 80% have also been described for high-grade splenic injuries. We discuss the role of computed tomography and transcatheter splenic artery embolization in the diagnosis and treatment of blunt splenic trauma. We review technical considerations, indications, efficacy and complication rates. We also propose an algorithm to guide the use of angiography and splenic embolization in patients with traumatic splenic injury.

Prospective multicenter study on robot-assisted laparoscopic extravesical ureteral reimplantation (RALUR-EV): Outcomes and complications.

PubMed

Boysen, William R; Akhavan, Ardavan; Ko, Joan; Ellison, Jonathan S; Lendvay, Thomas S; Huang, Jonathan; Garcia-Roig, Michael; Kirsch, Andrew; Koh, Chester J; Schulte, Marion; Noh, Paul; Monn, M Francesca; Whittam, Benjamin; Kawal, Trudy; Shukla, Aseem; Srinivasan, Arun; Gundeti, Mohan S

2018-02-20

Robot-assisted laparoscopic extravesical ureteral reimplantation (RALUR-EV) is a minimally invasive alternative to open surgery. We have previously reported retrospective outcomes from our study group, and herein provide an updated prospective analysis with a focus on success rate, surgical technique, and complications among surgeons who have overcome the initial learning curve. To assess the safety and efficacy of RALUR-EV in children, among experienced surgeons. We reviewed our prospective database of children undergoing RALUR-EV by pediatric urologists at eight academic centers from 2015 to 2017. Radiographic success was defined as absence of vesicoureteral reflux (VUR) on postoperative voiding cystourethrogram. Complications were graded using the Clavien scale. Univariate regression analysis was performed to assess for association among various patient and technical factors and radiographic failure. In total, 143 patients were treated with RALUR-EV for primary VUR (87 unilateral, 56 bilateral; 199 ureters). The majority of ureters (73.4%) had grade III or higher VUR preoperatively. Radiographic resolution was present in 93.8% of ureters, as shown in the summary table. Ureteral complications occurred in five ureters (2.5%) with mean follow-up of 7.4 months (SD 4.0). Transient urinary retention occurred in four patients following bilateral procedure (7.1%) and in no patients after unilateral. On univariate analysis, there were no patient or technical factors associated with increased odds of radiographic failure. We report a radiographic success rate of 93.8% overall, and 94.1% among children with grades III-V VUR. In contemporary series, alternate management options such as endoscopic injection and open UR have reported radiographic success rates of 90% and 93.5% respectively. We were unable to identify specific patient or technical factors that influenced outcomes, although immeasurable factors such as tissue handling and intraoperative decision-making could not be assessed. Ureteral complications requiring operative intervention were rare and occurred with the same incidence reported in a large open series. Limitations include lack of long-term follow-up and absence of radiographic follow-up on a subset of patients. Radiographic resolution of VUR following RALUR is on par with contemporary open series, and the incidence of ureteral complications is low. RALUR should be considered as one of several viable options for management of VUR in children. Copyright © 2018. Published by Elsevier Ltd.

Rescuing the Clinical Breast Examination: Advances in Classifying Technique and Assessing Physician Competency.

PubMed

Laufer, Shlomi; D'Angelo, Anne-Lise D; Kwan, Calvin; Ray, Rebbeca D; Yudkowsky, Rachel; Boulet, John R; McGaghie, William C; Pugh, Carla M

2017-12-01

Develop new performance evaluation standards for the clinical breast examination (CBE). There are several, technical aspects of a proper CBE. Our recent work discovered a significant, linear relationship between palpation force and CBE accuracy. This article investigates the relationship between other technical aspects of the CBE and accuracy. This performance assessment study involved data collection from physicians (n = 553) attending 3 different clinical meetings between 2013 and 2014: American Society of Breast Surgeons, American Academy of Family Physicians, and American College of Obstetricians and Gynecologists. Four, previously validated, sensor-enabled breast models were used for clinical skills assessment. Models A and B had solitary, superficial, 2 cm and 1 cm soft masses, respectively. Models C and D had solitary, deep, 2 cm hard and moderately firm masses, respectively. Finger movements (search technique) from 1137 CBE video recordings were independently classified by 2 observers. Final classifications were compared with CBE accuracy. Accuracy rates were model A = 99.6%, model B = 89.7%, model C = 75%, and model D = 60%. Final classification categories for search technique included rubbing movement, vertical movement, piano fingers, and other. Interrater reliability was (k = 0.79). Rubbing movement was 4 times more likely to yield an accurate assessment (odds ratio 3.81, P < 0.001) compared with vertical movement and piano fingers. Piano fingers had the highest failure rate (36.5%). Regression analysis of search pattern, search technique, palpation force, examination time, and 6 demographic variables, revealed that search technique independently and significantly affected CBE accuracy (P < 0.001). Our results support measurement and classification of CBE techniques and provide the foundation for a new paradigm in teaching and assessing hands-on clinical skills. The newly described piano fingers palpation technique was noted to have unusually high failure rates. Medical educators should be aware of the potential differences in effectiveness for various CBE techniques.

Fibrin sheaths in central venous port catheters: treatment with low-dose, single injection of urokinase on an outpatient basis.

PubMed

Chang, De-Hua; Mammadov, Kamal; Hickethier, Tilman; Borggrefe, Jan; Hellmich, Martin; Maintz, David; Kabbasch, Christoph

2017-01-01

Evaluation of the efficacy of single-shot, low-dose urokinase administration for the treatment of port catheter-associated fibrin sheaths. Forty-six patients were retrospectively evaluated for 54 episodes of port catheter dysfunction. The presence of a fibrin sheath was detected by angiographic contrast examinations. On an outpatient basis, patients subsequently received thrombolysis consisting of a single injection of urokinase (15.000 IU in 1.5 mL normal saline) through the port system. A second attempt was made in cases of treatment failure. Patients were followed up for technical success, complications and long-term outcome. Port dysfunction occurred at a median of 117 days after implantation (range: 7-825 days). The technical success after first port dysfunction by thrombolysis was 87% (40/46); thereof, initial thrombolysis was effective in 78% (36/46). Nine patients (20%) received a second dose of urokinase after previous treatment failure. Follow-up was available for 26 of 40 patients after successful thrombolysis. In 8 of these, rethrombosis occurred after a median of 98 days (range: 21-354 days), whereby rethrombolysis was effective in 5 of 7 (63%) patients. The overall success of all thrombolyses performed was 70% (45/64). No procedure-related technical or clinical complications occurred. After first favorable thrombolysis, a Kaplan-Meier analysis yielded a 30-, 90- and 180-day probability of patency of 96%, 87% and 81%. Thrombolytic therapy on an outpatient basis appears to be a safe and efficient. Three-month patency rates are comparable to more invasive treatment options, including catheter exchange over a guide wire and percutaneous fibrin sheath stripping.

Fibrin sheaths in central venous port catheters: treatment with low-dose, single injection of urokinase on an outpatient basis

PubMed Central

Chang, De-Hua; Mammadov, Kamal; Hickethier, Tilman; Borggrefe, Jan; Hellmich, Martin; Maintz, David; Kabbasch, Christoph

2017-01-01

Purpose Evaluation of the efficacy of single-shot, low-dose urokinase administration for the treatment of port catheter-associated fibrin sheaths. Methods Forty-six patients were retrospectively evaluated for 54 episodes of port catheter dysfunction. The presence of a fibrin sheath was detected by angiographic contrast examinations. On an outpatient basis, patients subsequently received thrombolysis consisting of a single injection of urokinase (15.000 IU in 1.5 mL normal saline) through the port system. A second attempt was made in cases of treatment failure. Patients were followed up for technical success, complications and long-term outcome. Results Port dysfunction occurred at a median of 117 days after implantation (range: 7–825 days). The technical success after first port dysfunction by thrombolysis was 87% (40/46); thereof, initial thrombolysis was effective in 78% (36/46). Nine patients (20%) received a second dose of urokinase after previous treatment failure. Follow-up was available for 26 of 40 patients after successful thrombolysis. In 8 of these, rethrombosis occurred after a median of 98 days (range: 21–354 days), whereby rethrombolysis was effective in 5 of 7 (63%) patients. The overall success of all thrombolyses performed was 70% (45/64). No procedure-related technical or clinical complications occurred. After first favorable thrombolysis, a Kaplan–Meier analysis yielded a 30-, 90- and 180-day probability of patency of 96%, 87% and 81%. Conclusion Thrombolytic therapy on an outpatient basis appears to be a safe and efficient. Three-month patency rates are comparable to more invasive treatment options, including catheter exchange over a guide wire and percutaneous fibrin sheath stripping. PMID:28182117

Vocational Education and Training: A Major Shift in World Bank Policy.

ERIC Educational Resources Information Center

Foster, Phillip

1992-01-01

Comments on the World Bank's policy paper on vocational and technical education and training. Argues that past failures in establishing effective vocational and technical education were a result of not applying conventional neoclassical economic theory. Asserts that the World Bank's policy paper corrects this approach. (CFR)

Index of congenital Minamata disease in Canadian areas of concern in the Great Lakes: an eco-social epidemiological approach.

PubMed

Gilbertson, Michael

2009-10-01

Cerebral palsy is one of the symptoms of congenital Minamata disease associated with exposure to methyl mercury. Cerebral palsy hospitalization rates for 17 Canadian Areas of Concern have been used as a health index in evaluating the effectiveness of the United States and Canadian governments in implementing their Great Lakes Water Quality Agreement. Elevated rates in males in several locations was associated with historic uses of mercury and with natural sources indicating that the governments have failed to protect human health from exposures to this persistent toxic substance. Advances in epidemiological theory indicate that the reasons for this failure cannot be explained solely in scientific and technical frames but that the social, economic, and political contexts of the two nations need to be examined.

[Laparoscopic sterilization with electrocautery: complications and reliability (author's transl)].

PubMed

Bänninger, U; Kunz, J; Schreiner, W E

1979-05-01

1084 laparoscopic sterilizations were evaluated in a retrospective study at the Universitäts-Frauenklinik Zürich. The operative and early postoperative complications and the reliability of the method were analysed and compared to the results in the literature. Based on a cumulative statistical analysis 0,5% intraoperative complications required laparotomy, the main indications being haemorrhages and bowel injuries. Failed attempts were encountered in one of 150 patients, the main causes of which were adhaesions and difficulties at establishing pneumoperitoneum. The failure rate of the laparoscopic electrocoagulation of the fallopian tube after a long-term follow-up was about 0,5%, 20--25% of these were ectopic pregnancies. The transection of the fallopian tubes did not diminish the pregnancy rate, but the risk of bleeding was considerably higher with this technic. Concurrently performed therapeutic abortion or preceeeding laparotomy did not increase the operative complication rate.

The role of interventional radiology in abdominopelvic trauma

PubMed Central

Ierardi, Anna Maria; Duka, Ejona; Lucchina, Natalie; Floridi, Chiara; De Martino, Alessandro; Donat, Daniela; Fontana, Federico

2016-01-01

The management of trauma patients has evolved in recent decades owing to increasing availability of advanced imaging modalities such as CT. Nowadays, CT has replaced the diagnostic function of angiography. The latter is considered when a therapeutic option is hypothesized. Arterial embolization is a life-saving procedure in abdominopelvic haemorrhagic patients, reducing relevant mortality rates and ensuring haemodynamic stabilization of the patient. Percutaneous transarterial embolization has been shown to be effective for controlling ongoing bleeding for patients with high-grade abdominopelvic injuries, thereby reducing the failure rate of non-operative management, preserving maximal organ function. Surgery is not always the optimal solution for stabilization of a patient with polytrauma. Mini-invasivity and repeatability may be considered as relevant advantages. We review technical considerations, efficacy and complication rates of hepatic, splenic, renal and pelvic embolization to extrapolate current evidence about transarterial embolization in traumatic patients. PMID:26642310

Midterm outcomes of the Zenith Renu AAA Ancillary Graft.

PubMed

Jim, Jeffrey; Rubin, Brian G; Geraghty, Patrick J; Money, Samuel R; Sanchez, Luis A

2011-08-01

The Zenith Renu abdominal aortic aneurysm (AAA) Ancillary Graft (Cook Medical Inc, Bloomington, Ind) provides active proximal fixation for treatment of pre-existing endografts with failed or failing proximal fixation or seal. The purpose of this study was to evaluate the midterm outcomes of treatment with this device. From September 2005 to November 2006, a prospective, nonrandomized, multicenter, postmarket registry was utilized to collect physician experiences from 151 cases (89 converters and 62 main body extensions) at 95 institutions. Preoperative indications and procedural and postimplantation outcomes were collected and analyzed. Technical success and clinical success were determined as defined by the Society of Vascular Surgery reporting standards. Patients were predominantly male (87%) with a mean age of 77 years. The interval between the original endograft implantation to Renu treatment was 43.4 ± 18.7 months. The indications for treatment were endoleak (n = 111), migration (n = 136), or both (n = 94). Technical success was 98.0% with two cases of intraoperative conversion and one case of persistent type IA endoleak. The median follow-up for the cohort was 45.0 months (range, 0-56 months; interquartile range, 25.0 months). Overall, 32 cases had treatment failures that included at least one of the following: death (n = 5), type I/III endoleak (n = 18), graft infection (n = 1), thrombosis (n = 1), aneurysm enlargement >5 mm (n = 9), rupture (n = 4), conversion (n = 9, with 7 after 30 days), and migration (n = 1). Overall, the clinical success for the entire cohort during the follow-up period was 78.8% (119/151). The postmarket registry data confirm that the Zenith Renu AAA Ancillary Graft can be used to treat endovascular repairs that failed due to proximal attachment failures. The salvage treatment with the Renu device had high technical success rate and resulted in clinical success in a majority of patients (78.8%). While failed endovascular repairs can be salvaged, a clinical failure in one of five patients still emphasizes the importance of patient and device selection during initial endovascular aneurysm repair to ensure durable success. Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Predictors of Perioperative Stroke/Death after Carotid Artery Stenting: A Review Article

PubMed Central

AbuRahma, Ali F.

2018-01-01

Carotid artery stenting (CAS) has been recommended as an alternative treatment to carotid endarterectomy for patients with significant carotid stenosis. Only a few studies have analyzed clinical/anatomical and technical variables that affect perioperative outcomes of CAS. Following a comprehensive Medline search, it was reported that clinical factors, including age of >80 years, chronic renal failure, diabetes mellitus, symptomatic indications, and procedures performed within 2 weeks of transient ischemic attack symptoms, are associated with high perioperative stroke and death rates. They also highlighted that angiographic variables, e.g., ulcerated and calcified plaques, left carotid intervention, >90% stenosis, >10-mm target lesion length, ostial involvement, type III aortic arch, and >60°-angulated internal carotid and common carotid arteries, are predictors of increased stroke rates. Technical factors associated with increased perioperative risk of stroke include percutaneous transluminal angioplasty (PTA) without embolic protection devices, PTA before stent placement, and the use of multiple stents. This review describes the most widely quoted data in defining various predictors of perioperative stroke and death after CAS. (This is a review article based on the invited lecture of the 45th Annual Meeting of Japanese Society for Vascular Surgery.) PMID:29682104

[What is the cause of failure of local anesthesia?].

PubMed

Vinckier, F

2000-01-01

Local anesthesia fails in 10% of cases of inferior alveolar nerve block and 7% of all cases of local anesthesia in general practice. Possible causes of failure are infection, wrong selection of local anesthetic solution, technical mistakes, anatomical variations with accessory innervation and anxiety of the patient. In this publication we discuss reasons for frequent failure in case of infection and in inferior alveolar nerve block. Understanding the mechanism of failure in local anesthesia, makes it possible to formulate guidelines to guarantee success. These measures are discussed in detail.

Heroic Reliability Improvement in Manned Space Systems

NASA Technical Reports Server (NTRS)

Jones, Harry W.

2017-01-01

System reliability can be significantly improved by a strong continued effort to identify and remove all the causes of actual failures. Newly designed systems often have unexpected high failure rates which can be reduced by successive design improvements until the final operational system has an acceptable failure rate. There are many causes of failures and many ways to remove them. New systems may have poor specifications, design errors, or mistaken operations concepts. Correcting unexpected problems as they occur can produce large early gains in reliability. Improved technology in materials, components, and design approaches can increase reliability. The reliability growth is achieved by repeatedly operating the system until it fails, identifying the failure cause, and fixing the problem. The failure rate reduction that can be obtained depends on the number and the failure rates of the correctable failures. Under the strong assumption that the failure causes can be removed, the decline in overall failure rate can be predicted. If a failure occurs at the rate of lambda per unit time, the expected time before the failure occurs and can be corrected is 1/lambda, the Mean Time Before Failure (MTBF). Finding and fixing a less frequent failure with the rate of lambda/2 per unit time requires twice as long, time of 1/(2 lambda). Cutting the failure rate in half requires doubling the test and redesign time and finding and eliminating the failure causes.Reducing the failure rate significantly requires a heroic reliability improvement effort.

Coil-Assisted Retrograde Transvenous Obliteration (CARTO) for the Treatment of Portal Hypertensive Variceal Bleeding: Preliminary Results

PubMed Central

Lee, Edward W; Saab, Sammy; Gomes, Antoinette S; Busuttil, Ronald; McWilliams, Justin; Durazo, Francisco; Han, Steven-Huy; Goldstein, Leonard; Tafti, Bashir A; Moriarty, John; Loh, Christopher T; Kee, Stephen T

2014-01-01

OBJECTIVES: To describe the technical feasibility, safety, and clinical outcomes of coil-assisted retrograde transvenous obliteration (CARTO) in treating portal hypertensive non-esophageal variceal hemorrhage. METHODS: From October 2012 to December 2013, 20 patients who received CARTO for the treatment of portal hypertensive non-esophageal variceal bleeding were retrospectively evaluated. All 20 patients had at least 6-month follow-up. All patients had detachable coils placed to occlude the efferent shunt and retrograde gelfoam embolization to achieve complete thrombosis/obliteration of varices. Technical success, clinical success, rebleeding, and complications were evaluated at follow-up. RESULTS: A 100% technical success rate (defined as achieving complete occlusion of efferent shunt with complete thrombosis/obliteration of bleeding varices and/or stopping variceal bleeding) was demonstrated in all 20 patients. Clinical success rate (defined as no variceal rebleeding) was 100%. Follow-up computed tomography after CARTO demonstrated decrease in size with complete thrombosis and disappearance of the varices in all 20 patients. Thirteen out of the 20 had endoscopic confirmation of resolution of varices. Minor post-CARTO complications, including worsening of esophageal varices (not bleeding) and worsening of ascites/hydrothorax, were noted in 5 patients (25%). One patient passed away at 24 days after the CARTO due to systemic and portal venous thrombosis and multi-organ failure. Otherwise, no major complication was noted. No variceal rebleeding was noted in all 20 patients during mean follow-up of 384±154 days. CONCLUSIONS: CARTO appears to be a technically feasible and safe alternative to traditional balloon-occluded retrograde transvenous obliteration or transjugular intrahepatic portosystemic shunt, with excellent clinical outcomes in treating portal hypertensive non-esophageal variceal bleeding. PMID:25273155

A simple technique to facilitate treatment of urethral strictures with optical internal urethrotomy.

PubMed

Stamatiou, Konstantinos; Papadatou, Aggeliki; Moschouris, Hippocrates; Kornezos, Ioannis; Pavlis, Anargiros; Christopoulos, Georgios

2014-01-01

Urethral stricture is a common condition that can lead to serious complications such as urinary infections and renal insufficiency secondary to urinary retention. Treatment options include catheterization, urethroplasty, endoscopic internal urethrotomy, and dilation. Optical internal urethrotomy offers faster recovery, minimal scarring, and less risk of infection, although recurrence is possible. However, technical difficulties associated with poor visualization of the stenosis or of the urethral lumen may increase procedural time and substantially increase the failure rates of internal urethrotomy. In this report we describe a technique for urethral catheterization via a suprapubic, percutaneous approach through the urinary bladder in order to facilitate endoscopic internal urethrotomy.

Magnetic Resonance Imaging-Guided High-Intensity Focused Ultrasound Ablation of Uterine Fibroids: Effect of Bowel Interposition on Procedure Feasibility and a Unique Bowel Displacement Technique.

PubMed

Kim, Young-Sun; Lim, Hyo Keun; Rhim, Hyunchul

2016-01-01

To evaluate the effect of bowel interposition on assessing procedure feasibility, and the usefulness and limiting conditions of bowel displacement techniques in magnetic resonance imaging-guided high-intensity focused ultrasound (MR-HIFU) ablation of uterine fibroids. Institutional review board approved this study. A total of 375 screening MR exams and 206 MR-HIFU ablations for symptomatic uterine fibroids performed between August 2010 and March 2015 were retrospectively analyzed. The effect of bowel interposition on procedure feasibility was assessed by comparing pass rates in periods before and after adopting a unique bowel displacement technique (bladder filling, rectal filling and subsequent bladder emptying; BRB maneuver). Risk factors for BRB failure were evaluated using logistic regression analysis. Overall pass rates of pre- and post-BRB periods were 59.0% (98/166) and 71.7% (150/209), and in bowel-interposed cases they were 14.6% (7/48) and 76.4% (55/72), respectively. BRB maneuver was technically successful in 81.7% (49/60). Through-the-bladder sonication was effective in eight of eleven BRB failure cases, thus MR-HIFU could be initiated in 95.0% (57/60). A small uterus on treatment day was the only significant risk factor for BRB failure (B = 0.111, P = 0.017). The BRB maneuver greatly reduces the fraction of patients deemed ineligible for MR-HIFU ablation of uterine fibroids due to interposed bowels, although care is needed when the uterus is small.

11 CFR 111.35 - If the respondent decides to challenge the alleged violation or proposed civil money penalty...

Code of Federal Regulations, 2010 CFR

2010-01-01

... staff; (4) Committee computer, software or Internet service provider failures; (5) A committee's failure... software despite the respondent seeking technical assistance from Commission personnel and resources; (2) A... Commission's or respondent's computer systems or Internet service provider; and (3) Severe weather or other...

Challenges of constructing salt cavern gas storage in China

NASA Astrophysics Data System (ADS)

Xia, Yan; Yuan, Guangjie; Ban, Fansheng; Zhuang, Xiaoqian; Li, Jingcui

2017-11-01

After more than ten years of research and engineering practice in salt cavern gas storage, the engineering technology of geology, drilling, leaching, completion, operation and monitoring system has been established. With the rapid growth of domestic consumption of natural gas, the requirement of underground gas storage is increasing. Because high-quality rock salt resources about 1000m depth are relatively scarce, the salt cavern gas storages will be built in deep rock salt. According to the current domestic conventional construction technical scheme, construction in deep salt formations will face many problems such as circulating pressure increasing, tubing blockage, deformation failure, higher completion risk and so on, caused by depth and the complex geological conditions. Considering these difficulties, the differences between current technical scheme and the construction scheme of twin well and big hole are analyzed, and the results show that the technical scheme of twin well and big hole have obvious advantages in reducing the circulating pressure loss, tubing blockage and failure risk, and they can be the alternative schemes to solve the technical difficulties of constructing salt cavern gas storages in the deep rock salt.

The impact of nontechnical skills on technical performance in surgery: a systematic review.

PubMed

Hull, Louise; Arora, Sonal; Aggarwal, Rajesh; Darzi, Ara; Vincent, Charles; Sevdalis, Nick

2012-02-01

Failures in nontechnical and teamwork skills frequently lie at the heart of harm and near-misses in the operating room (OR). The purpose of this systematic review was to assess the impact of nontechnical skills on technical performance in surgery. MEDLINE, EMBASE, PsycINFO databases were searched, and 2,041 articles were identified. After limits were applied, 341 articles were retrieved for evaluation. Of these, 28 articles were accepted for this review. Data were extracted from the articles regarding sample population, study design and setting, measures of nontechnical skills and technical performance, study findings, and limitations. Of the 28 articles that met inclusion criteria, 21 articles assessed the impact of surgeons' nontechnical skills on their technical performance. The evidence suggests that receiving feedback and effectively coping with stressful events in the OR has a beneficial impact on certain aspects of technical performance. Conversely, increased levels of fatigue are associated with detriments to surgical skill. One article assessed the impact of anesthesiologists' nontechnical skills on anesthetic technical performance, finding a strong positive correlation between the 2 skill sets. Finally, 6 articles assessed the impact of multiple nontechnical skills of the entire OR team on surgical performance. A strong relationship between teamwork failure and technical error was empirically demonstrated in these studies. Evidence suggests that certain nontechnical aspects of performance can enhance or, if lacking, contribute to deterioration of surgeons' technical performance. The precise extent of this effect remains to be elucidated. Copyright © 2012 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Towards a contemporary, comprehensive scoring system for determining technical outcomes of hybrid percutaneous chronic total occlusion treatment: The RECHARGE score.

PubMed

Maeremans, Joren; Spratt, James C; Knaapen, Paul; Walsh, Simon; Agostoni, Pierfrancesco; Wilson, William; Avran, Alexandre; Faurie, Benjamin; Bressollette, Erwan; Kayaert, Peter; Bagnall, Alan J; Smith, Dave; McEntegart, Margaret B; Smith, William H T; Kelly, Paul; Irving, John; Smith, Elliot J; Strange, Julian W; Dens, Jo

2018-02-01

This study sought to create a contemporary scoring tool to predict technical outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) from patients treated by hybrid operators with differing experience levels. Current scoring systems need regular updating to cope with the positive evolutions regarding materials, techniques, and outcomes, while at the same time being applicable for a broad range of operators. Clinical and angiographic characteristics from 880 CTO-PCIs included in the REgistry of CrossBoss and Hybrid procedures in FrAnce, the NetheRlands, BelGium and UnitEd Kingdom (RECHARGE) were analyzed by using a derivation and validation set (2:1 ratio). Variables significantly associated with technical failure in the multivariable analysis were incorporated in the score. Subsequently, the discriminatory capacity was assessed and the validation set was used to compare with the J-CTO score and PROGRESS scores. Technical success in the derivation and validation sets was 83% and 85%, respectively. Multivariate analysis identified six parameters associated with technical failure: blunt stump (beta coefficient (b) = 1.014); calcification (b = 0.908); tortuosity ≥45° (b = 0.964); lesion length 20 mm (b = 0.556); diseased distal landing zone (b = 0.794), and previous bypass graft on CTO vessel (b = 0.833). Score variables remained significant after bootstrapping. The RECHARGE score showed better discriminatory capacity in both sets (area-under-the-curve (AUC) = 0.783 and 0.711), compared to the J-CTO (AUC = 0.676) and PROGRESS (AUC = 0.608) scores. The RECHARGE score is a novel, easy-to-use tool for assessing the risk for technical failure in hybrid CTO-PCI and has the potential to perform well for a broad community of operators. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Method of Individual Forecasting of Technical State of Logging Machines

NASA Astrophysics Data System (ADS)

Kozlov, V. G.; Gulevsky, V. A.; Skrypnikov, A. V.; Logoyda, V. S.; Menzhulova, A. S.

2018-03-01

Development of the model that evaluates the possibility of failure requires the knowledge of changes’ regularities of technical condition parameters of the machines in use. To study the regularities, the need to develop stochastic models that take into account physical essence of the processes of destruction of structural elements of the machines, the technology of their production, degradation and the stochastic properties of the parameters of the technical state and the conditions and modes of operation arose.

Recent advances in lithotripsy technology and treatment strategies: A systematic review update

PubMed Central

Elmansy, H.E.; Lingeman, J.E.

2017-01-01

Introduction Shock wave lithotripsy (SWL) is a well – established treatment option for urolithiasis. The technology of SWL has undergone significant changes in an attempt to better optimize the results while reducing failure rates. There are some important limitations that restrict the use of SWL. In this review, we aim to place these advantages and limitations in perspective, assess the current role of SWL, and discuss recent advances in lithotripsy technology and treatment strategies. Methods A comprehensive review was conducted to identify studies reporting outcomes on ESWL. We searched for literature (PubMed, Embase, Medline) that focused on the physics of shock waves, theories of stone disintegration, and studies on optimising shock wave application. Relevant articles in English published since 1980 were selected for inclusion. Results Efficacy has been shown to vary between lithotripters. To maximize stone fragmentation and reduce failure rates, many factors can be optimized. Factors to consider in proper patient selection include skin – to – stone distance and stone size. Careful attention to the rate of shock wave administration, proper coupling of the treatment head to the patient have important influences on the success of lithotripsy. Conclusion Proper selection of patients who are expected to respond well to SWL, as well as attention to the technical aspects of the procedure are the keys to SWL success. Studies aiming to determine the mechanisms of shock wave action in stone breakage have begun to suggest new treatment strategies to improve success rates and safety. PMID:27890653

Implantation of programmable infusion pumps for insulin delivery in type I diabetic patients.

PubMed

Walter, H; Günther, A; Kronski, D; Flaschenträger, T; Mehnert, H

1989-06-01

Five type I diabetic patients were followed prospectively during treatment with continuous subcutaneous insulin infusion by externally worn pumps and during the first 12 months after implantation of a remote-controlled insulin infusion device (ID1, Siemens AG). Stabilized insulin (Hoe 21 GH, Hoechst AG) was infused intravenously in two and intraperitoneally in three patients. Total observation time was 47.2 patient-months after implantation. Two devices had to be explanted prematurely, one because of a technical failure after 101 days, one due to a skin necrosis over the implant after 236 days. HbA1, frequency of hypoglycemia, total insulin dose, and basal rate infusion did not change after implantation. There was a reduction in the insulin antibodies 6 months after start of intravenous or intraperitoneal insulin delivery. Fasting plasma free insulin levels could be normalized only by intraperitoneal insulin infusion. Although a technical and a surgical problem was observed, our data show the successful implantation and clinical use of programmable dosing devices and stabilized insulin.

Register of specialized sources for information on mechanics of structural failure

NASA Technical Reports Server (NTRS)

Carpenter, J. L., Jr.; Denny, F. J.

1973-01-01

Specialized information sources that generate information relative to six problem areas in aerospace mechanics of structural failure are identified. Selection for inclusion was based upon information obtained from the individual knowledge and professional contacts of Martin Marietta Aerospace staff members and the information uncovered by the staff of technical reviewers. Activities listed perform basic or applied research related to the mechanics of structural failure and publish the results of such research. The purpose of the register is to present, in easy reference form, original sources for dependable information regarding failure modes and mechanisms of aerospace structures.

40 CFR 63.140 - Process wastewater provisions-delay of repair.

Code of Federal Regulations, 2010 CFR

2010-07-01

... or a gap, crack, tear, or hole has been identified, is allowed if the repair is technically.... (b) Delay of repair of equipment for which a control equipment failure or a gap, crack, tear, or hole... equipment for which a control equipment failure or a gap, crack, tear, or hole has been identified is also...

Educational Technology Program. Quarterly Technical Summary, 1 March - 31 May 1972.

ERIC Educational Resources Information Center

Frick, Frederick C.

The results of the field trials of the Lincoln Training System (LTS-3) program are summarized in this report. The LTS-3 system was designed to teach basic electronics to Air Force personnel at Kessler Air Force Base, Mississippi. The results indicated that the instructional delays due to system failure were minimal, and those failures were…

ALS rocket engine combustion devices design and demonstration

NASA Technical Reports Server (NTRS)

Arreguin, Steve

1989-01-01

Work performed during Phase one is summarized and the significant technical and programmatic accomplishments occurring during this period are documented. Besides a summary of the results, methodologies, trade studies, design, fabrication, and hardware conditions; the following are included: the evolving Maintainability Plan, Reliability Program Plan, Failure Summary and Analysis Report, and the Failure Mode and Effect Analysis.

Capacity of scour-damaged bridges, part 2 : Integrated Analysis Program (IAP) - a program for the analysis of lateral performance of pile-supported structures under scour conditions, [technical summary].

DOT National Transportation Integrated Search

2013-11-01

Scour is the removal of soils in the vicinity of bridge foundations, resulting in a reduced capacity of the foundations, which can increase the risk of bridge failure. To minimize bridge failure, the Federal Highway Administration (FHWA) has establis...

Syntactical and Punctuation Errors: An Analysis of Technical Writing of University Students Science College, Taif University, KSA

ERIC Educational Resources Information Center

Alamin, Abdulamir; Ahmed, Sawsan

2012-01-01

Analyzing errors committed by second language learners during their first year of study at the University of Taif, can offer insights and knowledge of the learners' difficulties in acquiring technical English communication. With reference to the errors analyzed, the researcher found that the learners' failure to understand basic English grammar…

78 FR 77721 - Office of Small Credit Unions (OSCUI) Grant Program Access for Credit Unions

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-24

... any success or failure to meet objectives for use of proceeds, outcome, or impact. NCUA, in its sole... availability. The OSCUI Grant Program serves as a source of financial support, in the form of technical... provides financial support in the form of technical assistance grants to LICUs. These funds help improve...

S&MA Internship to Support Orion and the European Service Module

NASA Technical Reports Server (NTRS)

Hutcheson, Connor

2016-01-01

As a University Space Research Association (USRA) intern for NASA Johnson Space Center (JSC) during the summer 2016 work term, I worked on three main projects for the Space Exploration Division (NC) of the Safety and Mission Assurance (S&MA) Directorate. I worked on all three projects concurrently. One of the projects involved facilitating the status and closure of technical actions that were created during European Service Module (ESM) safety reviews by the MPCV Safety & Engineering Review Panel (MSERP). The two main duties included accurately collecting and summarizing qualitative data, and communicating that information to the European Space Agency (ESA) and Airbus (ESA's prime contractor) in a clear, succinct and precise manner. This project also required that I create a report on the challenges and opportunities of international S&MA. With its heavy emphasis on soft skills, this project taught me how to communicate better, by showing me how to present and share information in an easy-to-read and understandable format, and by showing me how to cooperate with and culturally respect international partners on a technical project. The second project involved working with the Orion Thermal Protection System (TPS) Process Failure Modes and Effects Analysis (PFMEA) Working Group to create the first full version of the Orion TPS PFMEA. The Orion TPS PFMEA Working Group met twice a week to analyze the Avcoat block installation process for failure modes, the failure modes effects, and how such failure modes could be controlled. I was in charge of implementing changes that were discussed in meeting, but were not implemented real time. Another major task included creating a significant portion of the content alongside another team member outside the two weekly meetings. This project caused me to become knowledgeable about TPS, heatshields, space-rated manufacturing, and non-destructive evaluation (NDE). The project also helped me to become better at working with a small team and helped improved my technical communication skills. My main duty for the third project was creating a Safety Verification Tracking Log (SVTL) for the Orbital Maneuvering System Engine (OMS-E), and contacting subject matter experts to close Hazard Report (HR) control verifications. This project also required me to support other OMS-E safety process tasks, like monitoring OMS-E vibration testing for Quality Assurance (QA) purposes. This project helped me become even more proficient in Excel. Throughout the project, I gained knowledge about the OMS-E system and improved my understanding of pressure systems and propellant systems. In terms of education goals, this work term has affirmed my desire to take a few more space-related courses, like orbital mechanics, so that I can have a better understanding of human spaceflight and the industry surrounding it. However, the work term did not persuade me to pursue a master's degree. In terms of career goals, this work term has helped me clarify the direction I would like to head in the future. The perspective of three summer terms working for NASA in S&MA has allowed me to observe that most S&MA employees joined S&MA after working in other NASA directorates, such as Engineering or Flight Operations. It is my belief that it would be advantageous for both NASA and I for me to broaden my knowledge base and technical skill set by completing hands-on technical work on human spaceflight projects, and for me to integrate my safety experience directly into technical work in other directorates. The other significant advantage to this proposed situation is that if I were to eventually return to S&MA, I would be returning with a substantial set of hands-on technical experience and knowledge, which would be a significant resource for S&MA tasks and projects.

Prospective Multicenter Study on the Challenges Inherent to Using Large Cell-Type Stents for Bilateral Stent-in-Stent Placement in Patients with Inoperable Malignant Hilar Biliary Obstruction.

PubMed

Yang, Min Jae; Kim, Jin Hong; Hwang, Jae Chul; Yoo, Byung Moo; Lee, Sang Hyub; Ryu, Ji Kon; Kim, Yong-Tae; Woo, Sang Myung; Lee, Woo Jin; Jeong, Seok; Lee, Don Haeng

2018-06-22

Although endoscopic bilateral stent-in-stent placement is challenging, many recent studies have reported promising outcomes regarding technical success and endoscopic reintervention. This study aimed to evaluate the technical feasibility of stent-in-stent placement using large cell-type stents in patients with inoperable malignant hilar biliary obstruction. Forty-three patients with inoperable malignant hilar biliary obstruction from four academic centers were prospectively enrolled from March 2013 to June 2015. Bilateral stent-in-stent placement using two large cell-type stents was successfully performed in 88.4% of the patients (38/43). In four of the five cases with technical failure, the delivery sheath of the second stent became caught in the hook-cross-type vertex of the large cell of the first stent, and subsequent attempts to pass a guidewire and stent assembly through the mesh failed. Functional success was achieved in all cases with technical success. Stent occlusion occurred in 63.2% of patients (24/38), with a median patient survival of 300 days. The median stent patency was 198 days. The stent patency rate was 82.9%, 63.1%, and 32.1% at 3, 6, and 12 months, respectively. Endoscopic re-intervention was performed in 14 patients, whereas 10 underwent percutaneous drainage. Large cell-type stents for endoscopic bilateral stent-in-stent placement showed acceptable functional success and stent patency when technically successful. However, the technical difficulty associated with the entanglement of the second stent delivery sheath in the hook-cross-type vertex of the first stent may preclude large cell-type stents from being considered as a dedicated standard tool for stent-in-stent placement.

Imaging and transcatheter arterial embolization for traumatic splenic injuries: review of the literature

PubMed Central

Raikhlin, Antony; Baerlocher, Mark Otto; Asch, Murray R.; Myers, Andy

2008-01-01

The spleen is the most commonly injured visceral organ in blunt abdominal trauma in both adults and children. Nonoperative management is the current standard of practice for patients who are hemodynamically stable. However, simple observation alone has been reported to have a failure rate as high as 34%; the rate is even higher among patients with high-grade splenic injuries (American Association for the Surgery of Trauma [AAST] grade III–V). Over the past decade, angiography with transcatheter splenic artery embolization, an alternative nonoperative treatment for splenic injuries, has increased splenic salvage rates to as high as 97%. With the help of splenic artery embolization, success rates of more than 80% have also been described for high-grade splenic injuries. We discuss the role of computed tomography and transcatheter splenic artery embolization in the diagnosis and treatment of blunt splenic trauma. We review technical considerations, indications, efficacy and complication rates. We also propose an algorithm to guide the use of angiography and splenic embolization in patients with traumatic splenic injury. PMID:19057735

The safety of magnetic resonance imaging in patients with programmable implanted intrathecal drug delivery systems: a 3-year prospective study.

PubMed

De Andres, Jose; Villanueva, Vicente; Palmisani, Stefano; Cerda-Olmedo, German; Lopez-Alarcon, Maria Dolores; Monsalve, Vicente; Minguez, Ana; Martinez-Sanjuan, Vicente

2011-05-01

It is common clinical practice to perform magnetic resonance imaging (MRI) in patients with indwelling programmable intrathecal drug delivery (IDD) systems, although the safety of the procedure has never been documented. We performed a single-center, 3-year, prospective evaluation in patients with a programmable implanted IDD to assess patient discomfort, IDD technical failures, and adverse effects during and after exposure to MRI. Forty-three consecutive patients with an implanted programmable IDD system (SynchroMed® EL Implantable Infusion Pump, Model 8626L-18, and SynchroMed® II Model 8637-20, 8637-40; Medtronic, Inc., Minneapolis, MN) requiring a scheduled MRI evaluation were studied during a 3-year period. All MRI scans were performed with a 1.5-tesla clinical use magnet and a specific absorption rate of no more than 0.9 W/kg. Radiograph control was used to confirm postexposure pump rotor movement and detect system dislocations. IDD system failures, patient satisfaction, and discomfort were recorded. None of the patients experienced signs of drug overinfusion that could lead to hemodynamic, respiratory, or neurologic alterations. Radiologic evaluation after MRI revealed no spatial displacements of the intrathecal catheter tip or body pump, and programmer telemetry confirmed the infusion recovery. Patients' satisfaction after the procedure was high. Performing an MRI scan with the proposed protocol in patients with an implanted Medtronic programmable IDD system resulted in virtually no technical or medical complications. © 2011 International Anesthesia Research Society

Treatment and technical intervention time analysis of a robotic stereotactic radiotherapy system.

PubMed

Crop, F; Lacornerie, T; Szymczak, H; Felin, A; Bailleux, C; Mirabel, X; Lartigau, E

2014-02-01

The purpose of this study is to obtain a better operational knowledge of Stereotactic Body Radiotherapy (SBRT) treatments with CyberKnife(r). An analysis of both In-room Times (IRT) and technical interventions of 5 years of treatments was performed, during which more than 1600 patients were treated for various indications, including liver (21%), lung (29%), intracranial (13%), head and neck (11%) and prostate (7%). Technical interventions were recorded along with the time of the failure, time to the intervention, and the complexity and duration of the repair. Analyses of Time Between Failures (TBF) and Service Disrupting TBF(disr) were performed. Treatment time data and variability per indication and following different system upgrades were evaluated. Large variations of IRTs were found between indications, but also large variations for each indication. The combination of the time reduction Tool (using Iris(r)) and Improved Stop Handling was of major impact to shortening of treatment times. The first implementation of the Iris collimator alone did not lead to significantly shorter IRTs for us except during prostate treatments. This was mostly due to the addition at the same time of larger rotational compensation for prostate treatments (58 instead of 1.58). Significant differences of duration between the first fraction and following fractions of a treatment, representing the necessity of defining imaging parameters and explanation to patients, were found for liver (12 min) and lung treatments using Xsight(r) Spine (5 min). Liver and lung treatments represent the longest IRT's and involve the largest variability's in IRT. The malfunction rate of the system followed a Weibull distribution with the shape and scale parameters of 0.8 and 39.7. Mean TBF(disr) was 68 work hours. 60 to 80% of the service disrupting interventions were resolved within 30-60 min, 5% required external intervention and 30% occurred in the morning. The presented results can be applied in the evaluation of the required machine time in order to implement robotic radiosurgery for different indications. The analytical distributions of IRTs and technical interruptions can be used for simulations.

Contraceptive Failure in the United States: Estimates from the 2006-2010 National Survey of Family Growth.

PubMed

Sundaram, Aparna; Vaughan, Barbara; Kost, Kathryn; Bankole, Akinrinola; Finer, Lawrence; Singh, Susheela; Trussell, James

2017-03-01

Contraceptive failure rates measure a woman's probability of becoming pregnant while using a contraceptive. Information about these rates enables couples to make informed contraceptive choices. Failure rates were last estimated for 2002, and social and economic changes that have occurred since then necessitate a reestimation. To estimate failure rates for the most commonly used reversible methods in the United States, data from the 2006-2010 National Survey of Family Growth were used; some 15,728 contraceptive use intervals, contributed by 6,683 women, were analyzed. Data from the Guttmacher Institute's 2008 Abortion Patient Survey were used to adjust for abortion underreporting. Kaplan-Meier methods were used to estimate the associated single-decrement probability of failure by duration of use. Failure rates were compared with those from 1995 and 2002. Long-acting reversible contraceptives (the IUD and the implant) had the lowest failure rates of all methods (1%), while condoms and withdrawal carried the highest probabilities of failure (13% and 20%, respectively). However, the failure rate for the condom had declined significantly since 1995 (from 18%), as had the failure rate for all hormonal methods combined (from 8% to 6%). The failure rate for all reversible methods combined declined from 12% in 2002 to 10% in 2006-2010. These broad-based declines in failure rates reverse a long-term pattern of minimal change. Future research should explore what lies behind these trends, as well as possibilities for further improvements. © 2017 The Authors. Perspectives on Sexual and Reproductive Health published by Wiley Periodicals, Inc., on behalf of the Guttmacher Institute.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raudsepp, E.

A test is given to determine if an engineer suffers from one of the three barriers to technical success: fear of success, fear of failure, or perfectionism. As in most such tests, the middle way is best. Successful engineers know that perfection cannot be attained, that they don't have time to worry about failure or success, and that by aiming and perservering in doing things well, success can be achieved.

Mechanical Circulatory Support Devices for Acute Right Ventricular Failure.

PubMed

Kapur, Navin K; Esposito, Michele L; Bader, Yousef; Morine, Kevin J; Kiernan, Michael S; Pham, Duc Thinh; Burkhoff, Daniel

2017-07-18

Right ventricular (RV) failure remains a major cause of global morbidity and mortality for patients with advanced heart failure, pulmonary hypertension, or acute myocardial infarction and after major cardiac surgery. Over the past 2 decades, percutaneously delivered acute mechanical circulatory support pumps specifically designed to support RV failure have been introduced into clinical practice. RV acute mechanical circulatory support now represents an important step in the management of RV failure and provides an opportunity to rapidly stabilize patients with cardiogenic shock involving the RV. As experience with RV devices grows, their role as mechanical therapies for RV failure will depend less on the technical ability to place the device and more on improved algorithms for identifying RV failure, patient monitoring, and weaning protocols for both isolated RV failure and biventricular failure. In this review, we discuss the pathophysiology of acute RV failure and both the mechanism of action and clinical data exploring the utility of existing RV acute mechanical circulatory support devices. © 2017 American Heart Association, Inc.

Extracorporeal membrane oxygenation: experience in an adult medical ICU.

PubMed

Hermans, G; Meersseman, W; Wilmer, A; Meyns, B; Bobbaers, H

2007-06-01

Extracorporeal membrane oxygenation (ECMO) is a technology that can provide extracorporeal gas exchange to patients with severe pulmonary or cardiac dysfunction. We report on our clinical experience with ECMO in critically ill patients. We performed a retrospective analysis of 23 patients treated with ECMO in a medical intensive care unit in a tertiary referral academic centre. 13 patients were considered immunocompetent and 10 were immunocompromised when extracorporeal membrane oxygenation was started. 16 patients presented with acute respiratory distress syndrome (ARDS), 2 patients had intractable cardiac failure, and 5 patients had combined respiratory and cardiac failure. In 16 patients, a veno-venous bypass was constructed; in 7 patients, the initial bypass was venoarterial. 11 patients survived. In 2 patients technical complications were fatal. Our data indicate that patients with community-acquired pneumonia and no underlying disease will benefit most from this technique. However, long-term survival is possible in immunocompromised patients. Venoarterial bypass can carry a higher risk for technical complications. Increasing experience apparently also reduces the risk of technical complications.

The Impact of Career and Technical Education Programs on At-Risk Secondary Students

ERIC Educational Resources Information Center

Smith, Sabrina E.

2012-01-01

As the number of youth at risk for educational failure has increased, so has the debate over the appropriate nature of career and technical education (CTE) programs for such youth. The purpose of this study was to gain an understanding about the manner in which CTE programs within vocational schools affected secondary students at risk for…

Project Interface Requirements Process Including Shuttle Lessons Learned

NASA Technical Reports Server (NTRS)

Bauch, Garland T.

2010-01-01

Most failures occur at interfaces between organizations and hardware. Processing interface requirements at the start of a project life cycle will reduce the likelihood of costly interface changes/failures later. This can be done by adding Interface Control Documents (ICDs) to the Project top level drawing tree, providing technical direction to the Projects for interface requirements, and by funding the interface requirements function directly from the Project Manager's office. The interface requirements function within the Project Systems Engineering and Integration (SE&I) Office would work in-line with the project element design engineers early in the life cycle to enhance communications and negotiate technical issues between the elements. This function would work as the technical arm of the Project Manager to help ensure that the Project cost, schedule, and risk objectives can be met during the Life Cycle. Some ICD Lessons Learned during the Space Shuttle Program (SSP) Life Cycle will include the use of hardware interface photos in the ICD, progressive life cycle design certification by analysis, test, & operations experience, assigning interface design engineers to Element Interface (EI) and Project technical panels, and linking interface design drawings with project build drawings

Failure rates of mini-implants placed in the infrazygomatic region.

PubMed

Uribe, Flavio; Mehr, Rana; Mathur, Ajay; Janakiraman, Nandakumar; Allareddy, Veerasathpurush

2015-01-01

The purpose of this pilot study was to evaluate the failure rates of mini-implants placed in the infrazygomatic region and to evaluate factors that affect their stability. A retrospective cohort study of 30 consecutive patients (55 mini-implants) who had infrazygomatic mini-implants at a University Clinic were evaluated for failure rates. Patient, mini-implant, orthodontic, surgical, and mini-implant maintenance factors were evaluated by univariate logistic regression models for association to failure rates. A 21.8 % failure rate of mini-implants placed in the infazygomatic region was observed. None of the predictor variables were significantly associated with higher or lower odds for failed implants. Failure rates for infrazygomatic mini-implants were slightly higher than those reported in other maxilla-mandibular osseous locations. No predictor variables were found to be associated to the failure rates.

Fault tolerant vector control of induction motor drive

NASA Astrophysics Data System (ADS)

Odnokopylov, G.; Bragin, A.

2014-10-01

For electric composed of technical objects hazardous industries, such as nuclear, military, chemical, etc. an urgent task is to increase their resiliency and survivability. The construction principle of vector control system fault-tolerant asynchronous electric. Displaying recovery efficiency three-phase induction motor drive in emergency mode using two-phase vector control system. The process of formation of a simulation model of the asynchronous electric unbalance in emergency mode. When modeling used coordinate transformation, providing emergency operation electric unbalance work. The results of modeling transient phase loss motor stator. During a power failure phase induction motor cannot save circular rotating field in the air gap of the motor and ensure the restoration of its efficiency at rated torque and speed.

Effect of Component Failures on Economics of Distributed Photovoltaic Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lubin, Barry T.

2012-02-02

This report describes an applied research program to assess the realistic costs of grid connected photovoltaic (PV) installations. A Board of Advisors was assembled that included management from the regional electric power utilities, as well as other participants from companies that work in the electric power industry. Although the program started with the intention of addressing effective load carrying capacity (ELCC) for utility-owned photovoltaic installations, results from the literature study and recommendations from the Board of Advisors led investigators to the conclusion that obtaining effective data for this analysis would be difficult, if not impossible. The effort was then re-focusedmore » on assessing the realistic costs and economic valuations of grid-connected PV installations. The 17 kW PV installation on the University of Hartford's Lincoln Theater was used as one source of actual data. The change in objective required a more technically oriented group. The re-organized working group (changes made due to the need for more technically oriented participants) made site visits to medium-sized PV installations in Connecticut with the objective of developing sources of operating histories. An extensive literature review helped to focus efforts in several technical and economic subjects. The objective of determining the consequences of component failures on both generation and economic returns required three analyses. The first was a Monte-Carlo-based simulation model for failure occurrences and the resulting downtime. Published failure data, though limited, was used to verify the results. A second model was developed to predict the reduction in or loss of electrical generation related to the downtime due to these failures. Finally, a comprehensive economic analysis, including these failures, was developed to determine realistic net present values of installed PV arrays. Two types of societal benefits were explored, with quantitative valuations developed for both. Some societal benefits associated with financial benefits to the utility of having a distributed generation capacity that is not fossil-fuel based have been included into the economic models. Also included and quantified in the models are several benefits to society more generally: job creation and some estimates of benefits from avoiding greenhouse emissions. PV system failures result in a lowering of the economic values of a grid-connected system, but this turned out to be a surprisingly small effect on the overall economics. The most significant benefit noted resulted from including the societal benefits accrued to the utility. This provided a marked increase in the valuations of the array and made the overall value proposition a financially attractive one, in that net present values exceeded installation costs. These results indicate that the Department of Energy and state regulatory bodies should consider focusing on societal benefits that create economic value for the utility, confirm these quantitative values, and work to have them accepted by the utilities and reflected in the rate structures for power obtained from grid-connected arrays. Understanding and applying the economic benefits evident in this work can significantly improve the business case for grid-connected PV installations. This work also indicates that the societal benefits to the population are real and defensible, but not nearly as easy to justify in a business case as are the benefits that accrue directly to the utility.« less

Efficacy and Safety of Augmenting the Preclose Technique with a Collagen-Based Closure Device for Percutaneous Endovascular Aneurysm Repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, Rafiuddin, E-mail: rafiuddin.patel@ouh.nhs.uk; Juszczak, Maciej T.; Bratby, Mark J.

PurposeTo report our experience of selectively augmenting the preclose technique for percutaneous endovascular aneurysm repair (p-EVAR) with an Angio-Seal device as a haemostatic adjunct in cases of significant bleeding after tensioning the sutures of the suture-mediated closure devices.Materials and MethodsProspectively collected data for p-EVAR patients at our institute were analysed. Outcomes included technical success and access site complications. A logistic regression model was used to analyse the effects of sheath size, CFA features and stent graft type on primary failure of the preclose technique necessitating augmentation and also on the development of complications.Resultsp-EVAR was attempted via 122 CFA access sitesmore » with a median sheath size of 18-French (range 12- to 28-French). Primary success of the preclose technique was 75.4 % (92/122). Angio-Seal augmentation was utilised as an adjunct to the preclose technique in 20.5 % (25/122). The overall p-EVAR success rate was 95.1 % (116/122). There was a statistically significant relationship (p = 0.0093) between depth of CFA and primary failure of preclose technique. CFA diameter, calcification, type of stent graft and sheath size did not have significant effects on primary preclose technique failure. Overall 4.9 % (6/122) required surgical conversion but otherwise there were no major complications.ConclusionAugmentation with an Angio-Seal device is a safe and effective adjunct to increase the success rate of the preclose technique in p-EVAR.« less

Evaluation of technical quality and periapical health of root-filled teeth by using cone-beam CT

PubMed Central

Bilge Gülsüm, NUR; Evren, OK; ALTUNSOY, Mustafa; AĞLARCI, Osman Sami; ÇOLAK, Mehmet; GÜNGÖR, Enes

2014-01-01

Objective This study aimed to assess the quality of root fillings, coronal restorations, complications of all root-filled teeth and their association with apical periodontitis (AP) detected by cone-beam computed tomography (CBCT) images from an adult Turkish subpopulation. Material and Methods The sample for this study consisted of 242 patients (aging from 15 to 72 years) with 522 endodontically treated teeth that were assessed for technical quality of the root canal filling and periapical status of the teeth. Additionally, the apical status of each root-filled tooth was assessed according to the gender, dental arch, tooth type and age classification, undetected canals, instrument fracture, root fracture, apical resorption, apical lesion, furcation lesion and type and quality of the coronal structure. Statistical analysis was performed using percentages and chi-square test. Results The success rate of the root canal treatment was of 54.4%. The success rates of adequate and inadequate root canal treatment were not significantly different (p>0.05). Apical periodontitis was found in 228 (45.6%) teeth treated for root canals. Higher prevalence of AP was found in patients aging from 20 to 29 years [64 (27%) teeth] and in anterior (canines and incisors) teeth [97 (41%) teeth]. Conclusions The technical quality of root canal filling performed by dental practitioners in a Turkish subpopulation was consistent with a high prevalence of AP. The probable reasons for this failure are multifactorial, and there may be a need for improved undergraduate education and postgraduate courses to improve the clinical skills of dental practitioners in endodontics. PMID:25591019

Reintervention for stent occlusion after bilateral self-expandable metallic stent placement for malignant hilar biliary obstruction.

PubMed

Inoue, Tadahisa; Naitoh, Itaru; Okumura, Fumihiro; Ozeki, Takanori; Anbe, Kaiki; Iwasaki, Hiroyasu; Nishie, Hirotada; Mizushima, Takashi; Sano, Hitoshi; Nakazawa, Takahiro; Yoneda, Masashi; Joh, Takashi

2016-11-01

Endoscopic reintervention for stent occlusions following bilateral self-expandable metallic stent (SEMS) placement for malignant hilar biliary obstruction (MHBO) is challenging, and time to recurrent biliary obstruction (RBO) of the revisionary stent remains unclear. We aimed to clarify a suitable reintervention method for stent occlusions following bilateral SEMS placement for MHBO. Between 2002 and 2014, 52 consecutive patients with MHBO who underwent endoscopic reintervention for stent occlusion after bilateral SEMS placement were enrolled at two university hospitals and one tertiary care referral center. We retrospectively evaluated the technical and functional success rates of the reinterventions, and the time to RBO of the revisionary stents. Technical and functional success rates of the reinterventions were 92% (48/52) and 90% (43/48), respectively. Univariate analysis did not determine any significant predictive factors for technical and functional failures. Median time to RBO of the revisionary stents was 68 days. Median time to RBO was significantly longer for revisionary SEMS placement than for plastic stent placement (131 days vs 47 days, respectively; log-rank test, P = 0.005). Revisionary SEMS placement was the only independent factor that was significantly associated with a longer time to RBO of the revisionary stent in the multivariate Cox proportional hazards analysis (hazard ratio 0.37; 95% confidence interval 0.14-0.95; P = 0.039). Revisionary SEMS placement is a suitable endoscopic reintervention method for stent occlusion following bilateral SEMS placement from the perspective of time to RBO of the revisionary stent. © 2016 Japan Gastroenterological Endoscopy Society.

Microcoil Embolization for Acute Lower Gastrointestinal Bleeding

DOE Office of Scientific and Technical Information (OSTI.GOV)

D'Othee, Bertrand Janne, E-mail: bjanne@caregroup.harvard.edu; Surapaneni, Padmaja; Rabkin, Dmitry

2006-02-15

Purpose. To assess outcomes after microcoil embolization for active lower gastrointestinal (GI) bleeding. Methods. We retrospectively studied all consecutive patients in whom microcoil embolization was attempted to treat acute lower GI bleeding over 88 months. Baseline, procedural, and outcome parameters were recorded following current Society of Interventional Radiology guidelines. Outcomes included technical success, clinical success (rebleeding within 30 days), delayed rebleeding (>30 days), and major and minor complication rates. Follow-up consisted of clinical, endoscopic, and pathologic data. Results. Nineteen patients (13 men, 6 women; mean age {+-} 95% confidence interval = 70 {+-} 6 years) requiring blood transfusion (10 {+-}more » 3 units) had angiography-proven bleeding distal to the marginal artery. Main comorbidities were malignancy (42%), coagulopathy (28%), and renal failure (26%). Bleeding was located in the small bowel (n = 5), colon (n 13) or rectum (n = 1). Technical success was obtained in 17 patients (89%); 2 patients could not be embolized due to vessel tortuosity and stenoses. Clinical follow-up length was 145 {+-} 75 days. Clinical success was complete in 13 (68%), partial in 3 (16%), and failed in 2 patients (11%). Delayed rebleeding (3 patients, 27%) was always due to a different lesion in another bowel segment (0 late rebleeding in embolized area). Two patients experienced colonic ischemia (11%) and underwent uneventful colectomy. Two minor complications were noted. Conclusion. Microcoil embolization for active lower GI bleeding is safe and effective in most patients, with high technical and clinical success rates, no procedure-related mortality, and a low risk of bowel ischemia and late rebleeding.« less

Large-scale 3D modeling of projectile impact damage in brittle plates

NASA Astrophysics Data System (ADS)

Seagraves, A.; Radovitzky, R.

2015-10-01

The damage and failure of brittle plates subjected to projectile impact is investigated through large-scale three-dimensional simulation using the DG/CZM approach introduced by Radovitzky et al. [Comput. Methods Appl. Mech. Eng. 2011; 200(1-4), 326-344]. Two standard experimental setups are considered: first, we simulate edge-on impact experiments on Al2O3 tiles by Strassburger and Senf [Technical Report ARL-CR-214, Army Research Laboratory, 1995]. Qualitative and quantitative validation of the simulation results is pursued by direct comparison of simulations with experiments at different loading rates and good agreement is obtained. In the second example considered, we investigate the fracture patterns in normal impact of spheres on thin, unconfined ceramic plates over a wide range of loading rates. For both the edge-on and normal impact configurations, the full field description provided by the simulations is used to interpret the mechanisms underlying the crack propagation patterns and their strong dependence on loading rate.

Reliability Assessment and Activation Energy Study of Au and Pd-Coated Cu Wires Post High Temperature Aging in Nanoscale Semiconductor Packaging.

PubMed

Gan, C L; Hashim, U

2013-06-01

Wearout reliability and high temperature storage life (HTSL) activation energy of Au and Pd-coated Cu (PdCu) ball bonds are useful technical information for Cu wire deployment in nanoscale semiconductor device packaging. This paper discusses the influence of wire type on the wearout reliability performance of Au and PdCu wire used in fine pitch BGA package after HTSL stress at various aging temperatures. Failure analysis has been conducted to identify the failure mechanism after HTSL wearout conditions for Au and PdCu ball bonds. Apparent activation energies (Eaa) of both wire types are investigated after HTSL test at 150 °C, 175 °C and 200 °C aging temperatures. Arrhenius plot has been plotted for each ball bond types and the calculated Eaa of PdCu ball bond is 0.85 eV and 1.10 eV for Au ball bond in 110 nm semiconductor device. Obviously Au ball bond is identified with faster IMC formation rate with IMC Kirkendall voiding while PdCu wire exhibits equivalent wearout and or better wearout reliability margin compare to conventional Au wirebond. Lognormal plots have been established and its mean to failure (t 50 ) have been discussed in this paper.

Vulnerability Management for an Enterprise Resource Planning System

NASA Astrophysics Data System (ADS)

Goel, Shivani; Kiran, Ravi; Garg, Deepak

2012-09-01

Enterprise resource planning (ERP) systems are commonly used in technical educational institutions(TEIs). ERP systems should continue providing services to its users irrespective of the level of failure. There could be many types of failures in the ERP systems. There are different types of measures or characteristics that can be defined for ERP systems to handle the levels of failure. Here in this paper, various types of failure levels are identified along with various characteristics which are concerned with those failures. The relation between all these is summarized. The disruptions causing vulnerabilities in TEIs are identified .A vulnerability management cycle has been suggested along with many commercial and open source vulnerability management tools. The paper also highlights the importance of resiliency in ERP systems in TEIs.

Non-surgical biliary drainage - technique, indications and results.

PubMed

Riemann, J F; Lux, G; Rösch, W; Beickert-Sterba, A

1981-07-01

Nonsurgical biliary drainage offers a therapeutic alternative in the palliation of malignant obstructive jaundice. Two basic approaches are available. The percutaneous transhepatic method can be employed either for external drainage or for the placement of an internal endoprosthesis. In the case of the transduodenal, transpapillary approach, either a pigtail catheter can be placed, after prior papillotomy, or - with or without the need to split the papillar - a nasobiliary drainage tube can be introduced. Successful drainage was achieved in 67 patients. In the majority of cases, external drainage was performed as a palliative measure in inoperable carcinoma of the biliodigestive system. In addition, however, pre-operative temporary drainage was also carried out to reduce the risks of surgery in patients with severe obstructive jaundice. The complication rate was low. Apart from biliary peritonitis, cholangitis and minor bleeds were observed. The rate of failure for technical reasons was a relatively low 10%.

A randomized trial for the study of the elective surgical treatment of portal hypertension in mansonic schistosomiasis.

PubMed Central

da Silva, L C; Strauss, E; Gayotto, L C; Mies, S; Macedo, A L; da Silva, A T; Silva, E F; Lacet, C M; Antonelli, R H; Fermanian, J

1986-01-01

From 1977 to 1983, 94 patients with esophageal varices and gastrointestinal bleeding secondary to mansonic schistosomiasis were entered into a prospective randomized trial comparing the three operations mainly used in Brazil: esophagogastric devascularization associated with splenectomy (EGDS, 32 patients), classical splenorenal shunt (SRS, 32 patients), and distal splenorenal shunt (DSRS, 30 patients). The randomization was interrupted because of a significant incidence of portosystemic encephalopathy (PSE) in the SRS group (26%), as compared to the DSRS (7%) and EGDS (0%) groups. The rate of rebleeding was the same in the three groups, but the rate of failure, as defined by the presence of technical problems, postoperative complications, or death, was significantly higher in the SRS group. This 2-year follow-up shows that SRS should be abandoned in hepatosplenic schistosomiasis and that a comparison between DSRS and EGDS with a longer follow-up is urgently needed. PMID:3090954

USGS science in the gulf oil spill: Novel science applications in a crisis

USGS Publications Warehouse

McNutt, M.

2011-01-01

Marcia McNutt reflects on the role of the US Geological Survey (USGS) team following the Deepwater Horizon oil spill. Secretary Salazar asked Marcia McNutt to lead the Flow Rate Technical Group, a team charged by National Incident Commander Adm. Thad Allen with improving estimates of the oil discharge rate from the Macondo well as quickly as possible. Given the unprecedented nature of this spill, the team moved rapidly to deploy every reasonable approach. The team estimated the plume velocity from deep-sea video and from Woods Hole Oceanographic Institution's acoustic Doppler current profiler. The team calculated the total volume of the spill using aircraft remote sensing. After the unsuccessful top kill attempt in late May, during which large volumes of mud were pumped down the flowing well, an important part of understanding the failure of the procedure was answering the question.

Importance of limiting hohlraum leaks at cryogenic temperatures on NIF targets

DOE PAGES

Bhandarkar, Suhas; Teslich, Nick; Haid, Ben; ...

2017-08-18

Inertial confinement fusion targets are complex systems designed to allow fine control of temperature and pressure for making precise spherical ice layers of hydrogen isotopes at cryogenic temperatures. We discuss the various technical considerations for a maximum leak rate based on heat load considerations. This maximum flow rate turns out to bemore » $$5\\times 10^{-6}$$ standard cc per second, which can be caused by an orifice less than half a micron in diameter. This makes the identification of the location and resolution of the leak a significant challenge. To illustrate this, we showcase one example of a peculiar failure mode that appeared suddenly but persisted whereby target production yield was severely lowered. Identification of the leak source and the root cause requires very careful analysis of multiple thermomechanical aspects to ensure that the end solution is indeed the right remedy and is robust.« less

[In vitro fertilization at the Erasme Hospital: 10 years and 1000 pregnancies later...].

PubMed

Englert, Y; Van den Bergh, M; Delbaere, A; Devreker, F; Koenig, I; Hannes, M; Emiliani, S; Biramane, J; Vannin, A S; Govaerts, I; Holoye, A; Revelard, P

1999-10-01

This contribution summarize ten years of in vitro fertilization of clinical work. Activity growth, improvements of results (mean fertilization rate increased from 45% to 58%, fertilization failure dropped from 18% to 7%, pregnancy chances gains 9% to reach 44% per trial) and new treatments possibilities (severe male infertility) thanks to the ICSI technic were the major characteristics of this last ten years. The original anonymous oocyte donation program with donors permutation initiated as soon as 1990 has imposed itself due to it's exceptional efficiency with a pregnancy rate of 95% per oocyte pick up on a population of 46 donors and 145 recipient cycles. Thanks to the large population studied (4028 cycles, 1071 pregnancies), the tendencies in human fecundity (impact of age) and the risks linked to multiples pregnancies could be highlighted, stressing the importance of future developments presented in the other contributions following this general presentation of results.

Susceptibility to Welding Cracking, Welding Sensitivity, Susceptibility to Welding Seam Cracking, and Test Methods for These Failures

NASA Technical Reports Server (NTRS)

Zeyen, K. L.

1949-01-01

In the years after the First World war a very rapid development, which even today has by no means come to an end, took place in the field of welding; here also, as in most technical innovations, failures made their appearance. Thereupon comprehensive Investigations were undertaken by steel manufacturers and consumers with cooperation of the authorities. b most cases the reasons for failure could be determined and eliminated and further occurrences avoided by the use of new test methods.

Implant-Assisted Removable Partial Denture Prostheses: A Critical Review of Selected Literature.

PubMed

Bassetti, Renzo G; Bassetti, Mario A; Kuttenberger, Johannes

A critical review of selected relevant publications assessed clinical efficacy and effectiveness of implant-assisted removable partial dentures (IARPDs) with implant survival and failure rates, biologic and technical complications, and maintenance and patient satisfaction after rehabilitation as outcomes. Screening of three databases (Medline [PubMed], Embase [OVID], and the Cochrane Library [CENTRAL]) and a manual search of related articles were performed. Reports on outcomes from human studies conducted between 1 January 1980 and 31 May 2016 were considered. A quality assessment of the identified full-text articles was performed to assess risk of bias and to evaluate heterogeneity. Only nine studies were included, and all nine demonstrated high risk of bias. The mean observation period ranged from 1 to 10 years, and only four studies included at least one control group. The studies reported implant survival rates of 91.7% to 100%, abutment tooth survival rates of 79.2% to 100%, and prosthesis survival rates of 90% to 100%. Approximal peri-implant crestal bone level changes (ΔCBL) ranged from -0.17 to -2.2 mm. IARPDs were associated with a higher frequency of technical complications and maintenance interventions than biologic complications. Only two question-based studies assessed patient satisfaction before and after treatment, and both reported marked improvement. A meta-analysis was not possible because of substantial heterogeneity in study design. Limited availability of robust publications related to the selected review topic precluded significant conclusions. Nonetheless, the preliminary assessment suggests that IARPDs are a simple and cost-effective approach to providing symmetric prosthesis support and stability, plus improved patient satisfaction.

32 CFR 518.21 - Collection of fees and fee rates for technical data.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Fee rates-(1) Costs for a manual search of technical data. Type Grade Hourly rate ($) Clerical E9/GS 8... costs for technical data. Type Cost ($) Aerial photograph, maps, specifications, permits, charts... microfilm indices, each .10 (e) Review time costs of technical data. Type Grade Hourly rate($) Clerical E9...

32 CFR 518.21 - Collection of fees and fee rates for technical data.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Fee rates-(1) Costs for a manual search of technical data. Type Grade Hourly rate ($) Clerical E9/GS 8... costs for technical data. Type Cost ($) Aerial photograph, maps, specifications, permits, charts... microfilm indices, each .10 (e) Review time costs of technical data. Type Grade Hourly rate($) Clerical E9...

32 CFR 518.21 - Collection of fees and fee rates for technical data.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Fee rates-(1) Costs for a manual search of technical data. Type Grade Hourly rate ($) Clerical E9/GS 8... costs for technical data. Type Cost ($) Aerial photograph, maps, specifications, permits, charts... microfilm indices, each .10 (e) Review time costs of technical data. Type Grade Hourly rate($) Clerical E9...

32 CFR 518.21 - Collection of fees and fee rates for technical data.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Fee rates-(1) Costs for a manual search of technical data. Type Grade Hourly rate ($) Clerical E9/GS 8... costs for technical data. Type Cost ($) Aerial photograph, maps, specifications, permits, charts... microfilm indices, each .10 (e) Review time costs of technical data. Type Grade Hourly rate($) Clerical E9...

Detection of imminent vein graft occlusion: what is the optimal surveillance program?

PubMed

Tinder, Chelsey N; Bandyk, Dennis F

2009-12-01

The prediction of infrainguinal vein bypass failure remains an inexact judgment. Patient demographics, technical factors, and vascular laboratory graft surveillance testing are helpful in identifying a high-risk graft cohort. The optimal surveillance program to detect the bypass at risk for imminent occlusion continues to be developed, but required elements are known and include clinical assessment for new or changes in limb ischemia symptoms, measurement of ankle and/or toe systolic pressure, and duplex ultrasound imaging of the bypass graft. Duplex ultrasound assessment of bypass hemodynamics may be the most accurate method to detect imminent vein graft occlusion. The finding of low graft flow during intraoperative assessment or at a scheduled surveillance study predicts failure; and if associated with an occlusive lesion, a graft revision can prolong patency. The most common abnormality producing graft failure is conduit stenosis caused by myointimal hyperplasia; and the majority can be repaired by an endovascular intervention. Frequency of testing to detect the failing bypass should be individualized to the patient, the type of arterial bypass, and prior duplex ultrasound scan findings. The focus of surveillance is on identification of the low-flow arterial bypass and timely repair of detected critical stenosis defined by duplex velocity spectra criteria of a peak systolic velocity 300 cm/s and peak systolic velocity ratio across the stenosis >3.5-correlating with >70% diameter-reducing stenosis. When conducted appropriately, a graft surveillance program should result in an unexpected graft failure rate of <3% per year.

The effects of heart rate control in chronic heart failure with reduced ejection fraction.

PubMed

Grande, Dario; Iacoviello, Massimo; Aspromonte, Nadia

2018-07-01

Elevated heart rate has been associated with worse prognosis both in the general population and in patients with heart failure. Heart rate is finely modulated by neurohormonal signals and it reflects the balance between the sympathetic and the parasympathetic limbs of the autonomic nervous system. For this reason, elevated heart rate in heart failure has been considered an epiphenomenon of the sympathetic hyperactivation during heart failure. However, experimental and clinical evidence suggests that high heart rate could have a direct pathogenetic role. Consequently, heart rate might act as a pathophysiological mediator of heart failure as well as a marker of adverse outcome. This hypothesis has been supported by the observation that the positive effect of beta-blockade could be linked to the degree of heart rate reduction. In addition, the selective heart rate control with ivabradine has recently been demonstrated to be beneficial in patients with heart failure and left ventricular systolic dysfunction. The objective of this review is to examine the pathophysiological implications of elevated heart rate in chronic heart failure and explore the mechanisms underlying the effects of pharmacological heart rate control.

Evaluation of Window Failure Modes

DTIC Science & Technology

1999-12-01

U.S. Coast Guard Research and Development Center 1082 Shennecossett Road, Groton, CT 06340-6096 Report No. CG-D-08-00 EVALUATION OF WINDOW FAILURE...States Coast Guard Research & Development Center 1082 Shennecossett Road Groton, CT 06340-6096 11 I.Report No. CG-D-08-00 Technical Report...Development Center 1082 Shennecossett Road Groton,CT 06340-6096 12. Sponsoring Organization Name and Address U.S. Department of Transportation United

Composite Failures: A Comparison of Experimental Test Results and Computational Analysis Using XFEM

DTIC Science & Technology

2016-09-30

NUWC-NPT Technical Report 12,218 30 September 2016 Composite Failures: A Comparison of Experimental Test Results and Computational Analysis...A Comparison of Experimental Test Results and Computational Analysis Using XFEM 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...availability of measurement techniques, experimental testing of composite materials has largely outpaced the computational modeling ability, forcing

Reliability Prediction, Assessment and Growth

DTIC Science & Technology

1976-03-15

Technical contributors to the report were D. Kos, L. Townsend, J. Schiller, N . Thomopoulos and V. Allen. On the part of the government, the project was...Life Penodj n Useful Life Overall Life Characteristic Curve ] IH Weorout Stress Related _ Failures ŕ / . Wearouf Failures...costs. It should be pointed out that maintenance data usually include 22 Table 2-1 SELECTED ARMY HELICOPTERS 4 R =rad.of blade N =number NUMBER

Internal Consistency of General Outcome Measures in Grades 1-8. Technical Report # 0915

ERIC Educational Resources Information Center

Anderson, Daniel; Tindal, Gerald; Alonzo, Julie

2009-01-01

We developed alternate forms of a math test for use in both screening students at risk of failure and monitoring their progress over time. In this technical report, we present results of the screener, used in the fall of 2009. The 48-item test was aligned to the National Council of Teachers of Mathematics (NCTM) Curriculum Focal Point Standards…

Unicompartmental knee arthroplasty modes of failure: wear is not the main reason for failure: a multicentre study of 418 failed knees.

PubMed

Epinette, J-A; Brunschweiler, B; Mertl, P; Mole, D; Cazenave, A

2012-10-01

This study originated from a symposium held by the French Hip and Knee Society (Société française de la hanche et du genou [SFHG]) and was carried out to better assess the distribution of causes of unicompartmental knee arthroplasty (UKA) failures, as well as cause-specific delay to onset. Our working hypothesis was that most failures were traceable to wear occurring over a period of many years. A multicentre retrospective study (25 centres) was conducted in 418 failed UKAs performed between 1978 and 2009. We determined the prevalence and time to onset of the main reasons for revision surgery based upon available preoperative findings. Additional intraoperative findings were analysed. The results were compared to those of nation wide registries to evaluate the representativeness of our study population. Times to revision surgery were short: 19% of revisions occurred within the first year and 48.5% within the first 5 years. Loosening was the main reason for failure (45%), followed by osteoarthritis progression (15%) and, finally, by wear (12%). Other reasons were technical problems in 11.5% of cases, unexplained pain in 5.5%, and failure of the supporting bone in 3.6%. The infection rate was 1.9%. Our results were consistent with those of Swedish and Australian registries. Our hypothesis was not confirmed. The short time to failure in most cases suggests a major role for surgical technique issues. Morbidity related to the implant per se may be seen as moderate and not greater than with total knee prostheses. The good agreement between our data and those of nationwide registries indicates that our population was representative. A finer analysis is needed, indicating that the establishment of a French registry would be of interest. Copyright © 2012. Published by Elsevier Masson SAS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbee, D; McCarthy, A; Galavis, P

Purpose: Errors found during initial physics plan checks frequently require replanning and reprinting, resulting decreased departmental efficiency. Additionally, errors may be missed during physics checks, resulting in potential treatment errors or interruption. This work presents a process control created using the Eclipse Scripting API (ESAPI) enabling dosimetrists and physicists to detect potential errors in the Eclipse treatment planning system prior to performing any plan approvals or printing. Methods: Potential failure modes for five categories were generated based on available ESAPI (v11) patient object properties: Images, Contours, Plans, Beams, and Dose. An Eclipse script plugin (PlanCheck) was written in C# tomore » check errors most frequently observed clinically in each of the categories. The PlanCheck algorithms were devised to check technical aspects of plans, such as deliverability (e.g. minimum EDW MUs), in addition to ensuring that policy and procedures relating to planning were being followed. The effect on clinical workflow efficiency was measured by tracking the plan document error rate and plan revision/retirement rates in the Aria database over monthly intervals. Results: The number of potential failure modes the PlanCheck script is currently capable of checking for in the following categories: Images (6), Contours (7), Plans (8), Beams (17), and Dose (4). Prior to implementation of the PlanCheck plugin, the observed error rates in errored plan documents and revised/retired plans in the Aria database was 20% and 22%, respectively. Error rates were seen to decrease gradually over time as adoption of the script improved. Conclusion: A process control created using the Eclipse scripting API enabled plan checks to occur within the planning system, resulting in reduction in error rates and improved efficiency. Future work includes: initiating full FMEA for planning workflow, extending categories to include additional checks outside of ESAPI via Aria database queries, and eventual automated plan checks.« less

Treatment of varicocele with reference to age: a retrospective comparison of three minimally invasive procedures.

PubMed

Beutner, S; May, M; Hoschke, B; Helke, C; Lein, M; Roigas, J; Johannsen, M

2007-01-01

This study investigated whether the therapeutic efficacy and morbidity of three minimally invasive techniques for varicocele correction--laparoscopic varicocelectomy (LV), antegrade sclerotherapy (AS), and retrograde embolization (RE)--differed between children and adults. During a 10-year period, 356 procedures for varicocele correction, including 122 cases of LV, 108 cases of AS, and 126 cases of RE, were performed for 314 patients at our institution. Of these patients, 223 were 19 years of age or younger (group 1), and 133 were older than 19 years (group 2). Diagnosis and postoperative results were established clinically and with the use of Doppler ultrasonography. The failure rates and complications for each procedure were retrospectively evaluated and compared between the two age groups. The median follow-up period was 69 months (range, 6-122 months). For 25 patients (19.8%), RE was not feasible for technical reasons. In both groups, LV had a lower failure rate than AS or RE, but the difference between LV and AS was not significant in group 1 (7.7(% vs 11.9%; p > 0.5). Also in group 1, AS was associated with fewer complications than LV 1 (4.5% vs 15.4%; p < 0.05). In group 2, LV was significantly more effective in correcting varicoceles than the other two techniques (p < 0.01). In this group, the complication rates for all three procedures did not differ significantly (p > 0.05). In our experience, LV was more effective than AS or RE in correcting varicoceles. For children and adolescents, AS may be more indicated because of the slightly lower complication rate and similar recurrence rates, as compared with LV, for this age group. The higher incidence of postoperative hydrocele formation after LV warrants more refined techniques such as the lymphatic-sparing approach.

Multi-agent system as a new approach to effective chronic heart failure management: key considerations.

PubMed

Mohammadzadeh, Niloofar; Safdari, Reza; Rahimi, Azin

2013-09-01

Given the importance of the follow-up of chronic heart failure (CHF) patients to reduce common causes of re-admission and deterioration of their status that lead to imposing spiritual and physical costs on patients and society, modern technology tools should be used to the best advantage. The aim of this article is to explain key points which should be considered in designing an appropriate multi-agent system to improve CHF management. In this literature review articles were searched with keywords like multi-agent system, heart failure, chronic disease management in Science Direct, Google Scholar and PubMed databases without regard to the year of publications. Agents are an innovation in the field of artificial intelligence. Because agents are capable of solving complex and dynamic health problems, to take full advantage of e-Health, the healthcare system must take steps to make use of this technology. Key factors in CHF management through a multi-agent system approach must be considered such as organization, confidentiality in general aspects and design and architecture points in specific aspects. Note that use of agent systems only with a technical view is associated with many problems. Hence, in delivering healthcare to CHF patients, considering social and human aspects is essential. It is obvious that identifying and resolving technical and non-technical challenges is vital in the successful implementation of this technology.

Lying to ourselves: rationality, critical reflexivity, and the moral order as 'structured agency'.

PubMed

Goodman, Benny

2016-07-01

A report suggests that United States' army officers may engage in dishonest reporting regarding their compliance procedures. Similarly, nurses with espoused high ethical standards sometimes fail to live up to them and may do so while deceiving themselves about such practices. Reasons for lapses are complex. However, multitudinous managerial demands arising within 'technical and instrumental rationality' may impact on honest decision-making. This paper suggests that compliance processes, which operates within the social structural context of the technical and instrumental rationality manifest as 'managerialism', contributes to professional 'dishonesty' about lapses in care, sometimes through 'thoughtlessness'. The need to manage risk, measure, account, and control in order to deliver efficiency, effectiveness, and economy (technical rationality) thus has both unintended and dysfunctional consequences. Meeting compliance requirements may be mediated by factors such as the 'affect heuristic' and 'reflexive deliberations' as part of the 'structured agency' of nurses. It is the complexity of 'structured agency' which may explain why some nurses fail to respond to such things as sentinel events, a failure to recognize 'personal troubles' as 'public issues', a failure which to outsiders who expect rational and professional responses may seem inconceivable. There is a need to understand these processes so that nurses can critique the context in which they work and to move beyond either/or explanations of structure or agency for care failures, and professional dishonesty. © 2016 John Wiley & Sons Ltd.

Multi-Agent System as a New Approach to Effective Chronic Heart Failure Management: Key Considerations

PubMed Central

Mohammadzadeh, Niloofar; Rahimi, Azin

2013-01-01

Objectives Given the importance of the follow-up of chronic heart failure (CHF) patients to reduce common causes of re-admission and deterioration of their status that lead to imposing spiritual and physical costs on patients and society, modern technology tools should be used to the best advantage. The aim of this article is to explain key points which should be considered in designing an appropriate multi-agent system to improve CHF management. Methods In this literature review articles were searched with keywords like multi-agent system, heart failure, chronic disease management in Science Direct, Google Scholar and PubMed databases without regard to the year of publications. Results Agents are an innovation in the field of artificial intelligence. Because agents are capable of solving complex and dynamic health problems, to take full advantage of e-Health, the healthcare system must take steps to make use of this technology. Key factors in CHF management through a multi-agent system approach must be considered such as organization, confidentiality in general aspects and design and architecture points in specific aspects. Conclusions Note that use of agent systems only with a technical view is associated with many problems. Hence, in delivering healthcare to CHF patients, considering social and human aspects is essential. It is obvious that identifying and resolving technical and non-technical challenges is vital in the successful implementation of this technology. PMID:24195010

Safety and Effectiveness of Percutaneously Inserted Peritoneal Ports Compared to Surgically Inserted Ports in a Retrospective Study of 87 Patients with Ovarian Carcinoma over a 10-Year Period

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodley-Cook, Joel, E-mail: jwoodleycook@gmail.com; Tarulli, Emidio; Tan, Kong T.

PurposePlacement of peritoneal ports has become a favorable technique for direct chemotherapy infusion in treating peritoneal metastases from ovarian cancer. We aim to outline an approach to the percutaneous insertion of peritoneal ports and to characterize success and complication rates compared to surgically inserted ports.Materials and MethodsRetrospective analysis was collected from 87 patients who had peritoneal port insertion (28 inserted surgically and 59 percutaneously) for treatment of peritoneal metastases from ovarian cancer from July 2004 to July 2014. Complications were classified according to the SIR Clinical Practice Guidelines as major or minor.ResultsTechnical success rates for surgically and percutaneously inserted portsmore » were 100 and 96.7 %, respectively (p = 0.44), with the two percutaneous failures successful at a later date. There were no major complications in either group. Minor complication rates for surgically versus percutaneously inserted ports were 46.4 versus 22.0 %, respectively (p = 0.02). The infection rate for surgically inserted versus percutaneously inserted ports was 14.3 and 0 %, respectively (p = 0.002). The relative risk of developing a complication from percutaneous peritoneal port insertion without ascites was 3.4 (p = 0.04). For percutaneously inserted ports, the mean in-room procedure time was 81 ± 1.3 min and mean fluoroscopy time was 5.0 ± 4.5 min.ConclusionPercutaneously inserted peritoneal ports are a safe alternative to surgically inserted ports, demonstrating similar technical success and lower complication rates.« less

Long-term Survival of Straumann Dental Implants with TPS Surfaces: A Retrospective Study with a Follow-up of 12 to 23 Years.

PubMed

Becker, Stephan T; Beck-Broichsitter, Benedicta E; Rossmann, Christian M; Behrens, Eleonore; Jochens, Arne; Wiltfang, Jörg

2016-06-01

The aim of this study was to evaluate the long-term dental implant survival rates of Straumann dental implants in a university hospital environment over 12 to 23 years. A total of 388 Straumann dental implants with titanium-sprayed surfaces (TPS) were inserted in 92 patients between 1988 and 1999 in the Department of Oral and Maxillofacial Surgery of the University Hospital Schleswig-Holstein in Kiel, and they were reevaluated with standardized clinical and radiological exams. Kaplan-Meier analyses were performed for individual factors. Cox proportional hazard regression analysis was used to detect the factors influencing long-term implant failure. The long-term implant survival rate was 88.03% after an observation time of 12.2 to 23.5 years. Cox regression revealed statistically significant influences of the International Team for Implantology (ITI) implantation type (p = .00354) and tobacco smoking (p = .01264) on implant failure. A proportion 82.8% of the patients with implant losses had a medical history of periodontitis. Peri-implantitis was diagnosed in 9.7% of the remaining implants in the long-term survey. This study emphasized the long-term rehabilitation capabilities of Straumann dental implants in complex cases. The survival rates after several years constitute important information for patients, as well as for clinicians, in deciding about different concepts of tooth replacement. Patient-related and technical factors - determined before implant placement - could help to predict the risk of implant loss. © 2015 Wiley Periodicals, Inc.

Savannah River Site generic data base development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanton, C.H.; Eide, S.A.

This report describes the results of a project to improve the generic component failure data base for the Savannah River Site (SRS). A representative list of components and failure modes for SRS risk models was generated by reviewing existing safety analyses and component failure data bases and from suggestions from SRS safety analysts. Then sources of data or failure rate estimates were identified and reviewed for applicability. A major source of information was the Nuclear Computerized Library for Assessing Reactor Reliability, or NUCLARR. This source includes an extensive collection of failure data and failure rate estimates for commercial nuclear powermore » plants. A recent Idaho National Engineering Laboratory report on failure data from the Idaho Chemical Processing Plant was also reviewed. From these and other recent sources, failure data and failure rate estimates were collected for the components and failure modes of interest. This information was aggregated to obtain a recommended generic failure rate distribution (mean and error factor) for each component failure mode.« less

Using Technical Performance Measures

NASA Technical Reports Server (NTRS)

Garrett, Christopher J.; Levack, Daniel J. H.; Rhodes, Russel E.

2011-01-01

All programs have requirements. For these requirements to be met, there must be a means of measurement. A Technical Performance Measure (TPM) is defined to produce a measured quantity that can be compared to the requirement. In practice, the TPM is often expressed as a maximum or minimum and a goal. Example TPMs for a rocket program are: vacuum or sea level specific impulse (lsp), weight, reliability (often expressed as a failure rate), schedule, operability (turn-around time), design and development cost, production cost, and operating cost. Program status is evaluated by comparing the TPMs against specified values of the requirements. During the program many design decisions are made and most of them affect some or all of the TPMs. Often, the same design decision changes some TPMs favorably while affecting other TPMs unfavorably. The problem then becomes how to compare the effects of a design decision on different TPMs. How much failure rate is one second of specific impulse worth? How many days of schedule is one pound of weight worth? In other words, how to compare dissimilar quantities in order to trade and manage the TPMs to meet all requirements. One method that has been used successfully and has a mathematical basis is Utility Analysis. Utility Analysis enables quantitative comparison among dissimilar attributes. It uses a mathematical model that maps decision maker preferences over the tradeable range of each attribute. It is capable of modeling both independent and dependent attributes. Utility Analysis is well supported in the literature on Decision Theory. It has been used at Pratt & Whitney Rocketdyne for internal programs and for contracted work such as the J-2X rocket engine program. This paper describes the construction of TPMs and describes Utility Analysis. It then discusses the use of TPMs in design trades and to manage margin during a program using Utility Analysis.

Systematic analysis of video data from different human-robot interaction studies: a categorization of social signals during error situations.

PubMed

Giuliani, Manuel; Mirnig, Nicole; Stollnberger, Gerald; Stadler, Susanne; Buchner, Roland; Tscheligi, Manfred

2015-01-01

Human-robot interactions are often affected by error situations that are caused by either the robot or the human. Therefore, robots would profit from the ability to recognize when error situations occur. We investigated the verbal and non-verbal social signals that humans show when error situations occur in human-robot interaction experiments. For that, we analyzed 201 videos of five human-robot interaction user studies with varying tasks from four independent projects. The analysis shows that there are two types of error situations: social norm violations and technical failures. Social norm violations are situations in which the robot does not adhere to the underlying social script of the interaction. Technical failures are caused by technical shortcomings of the robot. The results of the video analysis show that the study participants use many head movements and very few gestures, but they often smile, when in an error situation with the robot. Another result is that the participants sometimes stop moving at the beginning of error situations. We also found that the participants talked more in the case of social norm violations and less during technical failures. Finally, the participants use fewer non-verbal social signals (for example smiling, nodding, and head shaking), when they are interacting with the robot alone and no experimenter or other human is present. The results suggest that participants do not see the robot as a social interaction partner with comparable communication skills. Our findings have implications for builders and evaluators of human-robot interaction systems. The builders need to consider including modules for recognition and classification of head movements to the robot input channels. The evaluators need to make sure that the presence of an experimenter does not skew the results of their user studies.

Systematic analysis of video data from different human–robot interaction studies: a categorization of social signals during error situations

PubMed Central

Giuliani, Manuel; Mirnig, Nicole; Stollnberger, Gerald; Stadler, Susanne; Buchner, Roland; Tscheligi, Manfred

2015-01-01

Human–robot interactions are often affected by error situations that are caused by either the robot or the human. Therefore, robots would profit from the ability to recognize when error situations occur. We investigated the verbal and non-verbal social signals that humans show when error situations occur in human–robot interaction experiments. For that, we analyzed 201 videos of five human–robot interaction user studies with varying tasks from four independent projects. The analysis shows that there are two types of error situations: social norm violations and technical failures. Social norm violations are situations in which the robot does not adhere to the underlying social script of the interaction. Technical failures are caused by technical shortcomings of the robot. The results of the video analysis show that the study participants use many head movements and very few gestures, but they often smile, when in an error situation with the robot. Another result is that the participants sometimes stop moving at the beginning of error situations. We also found that the participants talked more in the case of social norm violations and less during technical failures. Finally, the participants use fewer non-verbal social signals (for example smiling, nodding, and head shaking), when they are interacting with the robot alone and no experimenter or other human is present. The results suggest that participants do not see the robot as a social interaction partner with comparable communication skills. Our findings have implications for builders and evaluators of human–robot interaction systems. The builders need to consider including modules for recognition and classification of head movements to the robot input channels. The evaluators need to make sure that the presence of an experimenter does not skew the results of their user studies. PMID:26217266

Estimation procedures to measure and monitor failure rates of components during thermal-vacuum testing

NASA Technical Reports Server (NTRS)

Williams, R. E.; Kruger, R.

1980-01-01

Estimation procedures are described for measuring component failure rates, for comparing the failure rates of two different groups of components, and for formulating confidence intervals for testing hypotheses (based on failure rates) that the two groups perform similarly or differently. Appendix A contains an example of an analysis in which these methods are applied to investigate the characteristics of two groups of spacecraft components. The estimation procedures are adaptable to system level testing and to monitoring failure characteristics in orbit.

Risk analysis by FMEA as an element of analytical validation.

PubMed

van Leeuwen, J F; Nauta, M J; de Kaste, D; Odekerken-Rombouts, Y M C F; Oldenhof, M T; Vredenbregt, M J; Barends, D M

2009-12-05

We subjected a Near-Infrared (NIR) analytical procedure used for screening drugs on authenticity to a Failure Mode and Effects Analysis (FMEA), including technical risks as well as risks related to human failure. An FMEA team broke down the NIR analytical method into process steps and identified possible failure modes for each step. Each failure mode was ranked on estimated frequency of occurrence (O), probability that the failure would remain undetected later in the process (D) and severity (S), each on a scale of 1-10. Human errors turned out to be the most common cause of failure modes. Failure risks were calculated by Risk Priority Numbers (RPNs)=O x D x S. Failure modes with the highest RPN scores were subjected to corrective actions and the FMEA was repeated, showing reductions in RPN scores and resulting in improvement indices up to 5.0. We recommend risk analysis as an addition to the usual analytical validation, as the FMEA enabled us to detect previously unidentified risks.

White Paper: Landscape on Technical and Conceptual Requirements and Competence Framework in Drug/Disease Modeling and Simulation

PubMed Central

Vlasakakis, G; Comets, E; Keunecke, A; Gueorguieva, I; Magni, P; Terranova, N; Della Pasqua, O; de Lange, E C; Kloft, C

2013-01-01

Pharmaceutical sciences experts and regulators acknowledge that pharmaceutical development as well as drug usage requires more than scientific advancements to cope with current attrition rates/therapeutic failures. Drug disease modeling and simulation (DDM&S) creates a paradigm to enable an integrated and higher-level understanding of drugs, (diseased)systems, and their interactions (systems pharmacology) through mathematical/statistical models (pharmacometrics)1—hence facilitating decision making during drug development and therapeutic usage of medicines. To identify gaps and challenges in DDM&S, an inventory of skills and competencies currently available in academia, industry, and clinical practice was obtained through survey. The survey outcomes revealed benefits, weaknesses, and hurdles for the implementation of DDM&S. In addition, the survey indicated that no consensus exists about the knowledge, skills, and attributes required to perform DDM&S activities effectively. Hence, a landscape of technical and conceptual requirements for DDM&S was identified and serves as a basis for developing a framework of competencies to guide future education and training in DDM&S. PMID:23887723

Chandra High Resolution Camera (HRC). Rev. 59

NASA Technical Reports Server (NTRS)

Murray, Stephen

2004-01-01

This monthly report discusses management and general status, mission support and operations, and science activities. A technical memorandum entitled "Failure Analysis of HRC Flight Relay" is included with the report.

Adult venovenous extracorporeal membrane oxygenation for severe respiratory failure: Current status and future perspectives.

PubMed

Sen, Ayan; Callisen, Hannelisa E; Alwardt, Cory M; Larson, Joel S; Lowell, Amelia A; Libricz, Stacy L; Tarwade, Pritee; Patel, Bhavesh M; Ramakrishna, Harish

2016-01-01

Extracorporeal membrane oxygenation (ECMO) for severe acute respiratory failure was proposed more than 40 years ago. Despite the publication of the ARDSNet study and adoption of lung protective ventilation, the mortality for acute respiratory failure due to acute respiratory distress syndrome has continued to remain high. This technology has evolved over the past couple of decades and has been noted to be safe and successful, especially during the worldwide H1N1 influenza pandemic with good survival rates. The primary indications for ECMO in acute respiratory failure include severe refractory hypoxemic and hypercarbic respiratory failure in spite of maximum lung protective ventilatory support. Various triage criteria have been described and published. Contraindications exist when application of ECMO may be futile or technically impossible. Knowledge and appreciation of the circuit, cannulae, and the physiology of gas exchange with ECMO are necessary to ensure lung rest, efficiency of oxygenation, and ventilation as well as troubleshooting problems. Anticoagulation is a major concern with ECMO, and the evidence is evolving with respect to diagnostic testing and use of anticoagulants. Clinical management of the patient includes comprehensive critical care addressing sedation and neurologic issues, ensuring lung recruitment, diuresis, early enteral nutrition, treatment and surveillance of infections, and multisystem organ support. Newer technology that delinks oxygenation and ventilation by extracorporeal carbon dioxide removal may lead to ultra-lung protective ventilation, avoidance of endotracheal intubation in some situations, and ambulatory therapies as a bridge to lung transplantation. Risks, complications, and long-term outcomes and resources need to be considered and weighed in before widespread application. Ethical challenges are a reality and a multidisciplinary approach that should be adopted for every case in consideration.

The Author’s Guide To Writing 412th Test Wing Technical Reports

DTIC Science & Technology

2014-12-01

control CAD computer aided design cc cubic centimeters C.O. carry-over c/o checkout USAF United States Air Force C1 rolling moment coefficient...cooling air. Mission Impact: Results in maintenance inability to reliably duplicate and isolate valid aircraft failures, and degrades reliability...air. Mission Impact: Results in maintenance inability to reliably duplicate and isolate valid aircraft failures, and degrades reliability of system

ISS Solar Array Alpha Rotary Joint (SARJ) Bearing Failure and Recovery: Technical and Project Management Lessons Learned

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Krantz, Timothy L.; Dube, Michael J.

2011-01-01

The photovoltaic solar panels on the International Space Station (ISS) track the Sun through continuous rotating motion enabled by large bearings on the main truss called solar array alpha rotary joints (SARJs). In late 2007, shortly after installation, the starboard SARJ had become hard to turn and had to be shut down after exceeding drive current safety limits. The port SARJ, of the same design, had been working well for over 2 years. An exhaustive failure investigation ensued that included multiple extravehicular activities to collect information and samples for engineering forensics, detailed structural and thermal analyses, and a careful review of the build records. The ultimate root cause was determined to be kinematic design vulnerability coupled with inadequate lubrication, and manufacturing flaws; this was corroborated through ground tests, metallurgical studies, and modeling. A highly successful recovery plan was developed and implemented that included replacing worn and damaged components in orbit and applying space-compatible grease to improve lubrication. Beyond the technical aspects, however, lie several key programmatic lessons learned. These lessons, such as running ground tests to intentional failure to experimentally verify failure modes, are reviewed and discussed so they can be applied to future projects to avoid such problems.

A retrospective survey of the causes of bracket- and tube-bonding failures.

PubMed

Roelofs, Tom; Merkens, Nico; Roelofs, Jeroen; Bronkhorst, Ewald; Breuning, Hero

2017-01-01

To investigate the causes of bonding failures of orthodontic brackets and tubes and the effect of premedicating for saliva reduction. Premedication with atropine sulfate was administered randomly. Failure rate of brackets and tubes placed in a group of 158 consecutive patients was evaluated after a mean period of 67 weeks after bonding. The failure rate in the group without atropine sulfate premedication was 2.4%. In the group with premedication, the failure rate was 2.7%. The Cox regression analysis of these groups showed that atropine application did not lead to a reduction in bond failures. Statistically significant differences in the hazard ratio were found for the bracket regions and for the dental assistants who prepared for the bonding procedure. Premedication did not lead to fewer bracket failures. The roles of the dental assistant and patient in preventing failures was relevant. A significantly higher failure rate for orthodontic appliances was found in the posterior regions.

Effectiveness and predictors of failure of noninvasive mechanical ventilation in acute respiratory failure.

PubMed

Martín-González, F; González-Robledo, J; Sánchez-Hernández, F; Moreno-García, M N; Barreda-Mellado, I

2016-01-01

To assess the effectiveness and identify predictors of failure of noninvasive ventilation. A retrospective, longitudinal descriptive study was made. Adult patients with acute respiratory failure. A total of 410 consecutive patients with noninvasive ventilation treated in an Intensive Care Unit of a tertiary university hospital from 2006 to 2011. Noninvasive ventilation. Demographic variables and clinical and laboratory test parameters at the start and two hours after the start of noninvasive ventilation. Evolution during admission to the Unit and until hospital discharge. The failure rate was 50%, with an overall mortality rate of 33%. A total of 156 patients had hypoxemic respiratory failure, 87 postextubation respiratory failure, 78 exacerbation of chronic obstructive pulmonary disease, 61 hypercapnic respiratory failure without chronic obstructive pulmonary disease, and 28 had acute pulmonary edema. The failure rates were 74%, 54%, 27%, 31% and 21%, respectively. The etiology of respiratory failure, serum bilirubin at the start, APACHEII score, radiological findings, the need for sedation to tolerate noninvasive ventilation, changes in level of consciousness, PaO2/FIO2 ratio, respiratory rate and heart rate from the start and two hours after the start of noninvasive ventilation were independently associated to failure. The effectiveness of noninvasive ventilation varies according to the etiology of respiratory failure. Its use in hypoxemic respiratory failure and postextubation respiratory failure should be assessed individually. Predictors of failure could be useful to prevent delayed intubation. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

Self-healing biomaterials(3)

PubMed Central

Brochu, Alice B. W.; Craig, Stephen L.; Reichert, William M.

2010-01-01

The goal of this review is to introduce the biomaterials community to the emerging field of self-healing materials, and also to suggest how one could utilize and modify self-healing approaches to develop new classes of biomaterials. A brief discussion of the in vivo mechanical loading and resultant failures experienced by biomedical implants is followed by presentation of the self-healing methods for combating mechanical failure. If conventional composite materials that retard failure may be considered zeroth generation self-healing materials, then taxonomically-speaking, first generation self-healing materials describe approaches that “halt” and “fill” damage, whereas second generation self-healing materials strive to “fully restore” the pre-failed material structure. In spite of limited commercial use to date, primarily because the technical details have not been suitably optimized, it is likely from a practical standpoint that first generation approaches will be the first to be employed commercially, whereas second generation approaches may take longer to implement. For self-healing biomaterials the optimization of technical considerations is further compounded by the additional constraints of toxicity and biocompatibility, necessitating inclusion of separate discussions of design criteria for self-healing biomaterials. PMID:21171168

Ethical questions must be considered for electronic health records.

PubMed

Spriggs, Merle; Arnold, Michael V; Pearce, Christopher M; Fry, Craig

2012-09-01

National electronic health record initiatives are in progress in many countries around the world but the debate about the ethical issues and how they are to be addressed remains overshadowed by other issues. The discourse to which all others are answerable is a technical discourse, even where matters of privacy and consent are concerned. Yet a focus on technical issues and a failure to think about ethics are cited as factors in the failure of the UK health record system. In this paper, while the prime concern is the Australian Personally Controlled Electronic Health Record (PCEHR), the discussion is relevant to and informed by the international context. The authors draw attention to ethical and conceptual issues that have implications for the success or failure of electronic health records systems. Important ethical issues to consider as Australia moves towards a PCEHR system include: issues of equity that arise in the context of personal control, who benefits and who should pay, what are the legitimate uses of PCEHRs, and how we should implement privacy. The authors identify specific questions that need addressing.

Biomechanical effects of a 2 suture-pass medial inter-implant mattress on transosseous-equivalent rotator cuff repair and considerations for a "technical efficiency ratio".

PubMed

Park, Maxwell C; Peterson, Alexander; Patton, John; McGarry, Michelle H; Park, Chong J; Lee, Thay Q

2014-03-01

Rotator cuff repair involving fewer tendon suture passes without compromising biomechanical performance would represent a technical advancement. An inter-implant "medial pulley-mattress" transosseous-equivalent (MP-TOE) repair requiring fewer tendon suture-passes was hypothesized to provide equivalent biomechanical characteristics compared to the control. In 6 human cadaveric shoulders, a transosseous-equivalent (TOE) repair (control) was performed utilizing 2 separate medial mattresses resulting in 4 tendon-bridging sutures. In 6 matched-pairs, 2 single-loaded anchors were used to create a medial inter-implant mattress construct (all sutures shuttled in 1 tendon pass per anchor)-after knot-tying, the same tendon-bridging pattern as the control was created. A materials testing machine cyclically loaded each repair from 10-180 N for 30 cycles; each repair subsequently underwent failure testing. Gap and strain were measured with a video digitizing system. A "technical efficiency ratio" (TER) was defined as: (#knots + #suture passes + #suture limbs)/#fixation points. Cyclic and failure testing demonstrated no significant differences between constructs. Gap formation at cycle 30 was 5.3 ± 0.8 mm (TOE) and 5.0 ± 0.3 mm (MP-TOE) (P = .62). Cycle 30 anterior strain values were -16.0 ± 7.3% (TOE) and -15.8 ± 6.6% (MP-TOE) (P = .99). Yield loads were 208.7 ± 2.7 N (TOE) and 204.0 ± 1.3 N (MP-TOE) (P = .17). Mode of failure demonstrated less tendon cut-out with the MP-TOE repair. The MP-TOE repair has a TER of 2.0 vs 2.5 for the control. The MP-TOE repair requiring fewer tendon suture passes, yet creating an additional inter-implant mattress configuration, is biomechanically equivalent to the original TOE technique, and may limit failure with improved medial load-sharing capacity. A TER may help quantify technical ease and help standardize comparisons between repair techniques. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion

NASA Astrophysics Data System (ADS)

1980-06-01

The feasibility of the nickel zinc battery for electric vehicle propulsion is discussed. The program is divided into seven distinct but highly interactive tasks collectively aimed at the development and commercialization of nickel zinc technology. These basic technical tasks are separator development, electrode development, product design and analysis, cell/module battery testing, process development, pilot manufacturing, and thermal manufacturing, and thermal management. Significant progress has been made in the understanding of separator failure mechanisms, and a generic category of materials has been specified for the 300+ deep discharge applications. Shape change has been reduced significantly. Progress in the area of thermal management was significant, with the development of a model that accurately represents heat generation and rejection rates during battery operation.

Treatment Failure With Rhythm and Rate Control Strategies in Patients With Atrial Fibrillation and Congestive Heart Failure: An AF-CHF Substudy.

PubMed

Dyrda, Katia; Roy, Denis; Leduc, Hugues; Talajic, Mario; Stevenson, Lynne Warner; Guerra, Peter G; Andrade, Jason; Dubuc, Marc; Macle, Laurent; Thibault, Bernard; Rivard, Lena; Khairy, Paul

2015-12-01

Rate and rhythm control strategies for atrial fibrillation (AF) are not always effective or well tolerated in patients with congestive heart failure (CHF). We assessed reasons for treatment failure, associated characteristics, and effects on survival. A total of 1,376 patients enrolled in the AF-CHF trial were followed for 37  ±  19 months, 206 (15.0%) of whom failed initial therapy leading to crossover. Rhythm control was abandoned more frequently than rate control (21.0% vs. 9.1%, P < 0.0001). Crossovers from rhythm to rate control were driven by inefficacy, whereas worsening heart failure was the most common reason to crossover from rate to rhythm control. In multivariate analyses, failure of rhythm control was associated with female sex, higher serum creatinine, functional class III or IV symptoms, lack of digoxin, and oral anticoagulation. Factors independently associated with failure of rate control were paroxysmal (vs. persistent) AF, statin therapy, and presence of an implantable cardioverter-defibrillator. Crossovers were not associated with cardiovascular mortality (hazard ratio [HR] 1.11 from rhythm to rate control; 95% confidence interval [95% CI, 0.73-1.73]; P = 0.6069; HR 1.29 from rate to rhythm control; 95% CI, 0.73-2.25; P = 0.3793) or all-cause mortality (HR 1.16 from rhythm to rate control, 95% CI [0.79-1.72], P = 0.4444; HR 1.15 from rate to rhythm control, 95% [0.69, 1.91], P = 0.5873). Rhythm control is abandoned more frequently than rate control in patients with AF and CHF. The most common reasons for treatment failure are inefficacy for rhythm control and worsening heart failure for rate control. Changing strategies does not impact survival. © 2015 Wiley Periodicals, Inc.

Reliability analysis of C-130 turboprop engine components using artificial neural network

NASA Astrophysics Data System (ADS)

Qattan, Nizar A.

In this study, we predict the failure rate of Lockheed C-130 Engine Turbine. More than thirty years of local operational field data were used for failure rate prediction and validation. The Weibull regression model and the Artificial Neural Network model including (feed-forward back-propagation, radial basis neural network, and multilayer perceptron neural network model); will be utilized to perform this study. For this purpose, the thesis will be divided into five major parts. First part deals with Weibull regression model to predict the turbine general failure rate, and the rate of failures that require overhaul maintenance. The second part will cover the Artificial Neural Network (ANN) model utilizing the feed-forward back-propagation algorithm as a learning rule. The MATLAB package will be used in order to build and design a code to simulate the given data, the inputs to the neural network are the independent variables, the output is the general failure rate of the turbine, and the failures which required overhaul maintenance. In the third part we predict the general failure rate of the turbine and the failures which require overhaul maintenance, using radial basis neural network model on MATLAB tool box. In the fourth part we compare the predictions of the feed-forward back-propagation model, with that of Weibull regression model, and radial basis neural network model. The results show that the failure rate predicted by the feed-forward back-propagation artificial neural network model is closer in agreement with radial basis neural network model compared with the actual field-data, than the failure rate predicted by the Weibull model. By the end of the study, we forecast the general failure rate of the Lockheed C-130 Engine Turbine, the failures which required overhaul maintenance and six categorical failures using multilayer perceptron neural network (MLP) model on DTREG commercial software. The results also give an insight into the reliability of the engine turbine under actual operating conditions, which can be used by aircraft operators for assessing system and component failures and customizing the maintenance programs recommended by the manufacturer.

Trends in liability affecting technical writers

NASA Technical Reports Server (NTRS)

Driskill, L. P.

1981-01-01

Liability of technical writers for defective products is explored. Documents generated during a product's life cycle (including design memos, design tests, clinical trials, trial use reports, letters, and proposals) become relevant because they are likely to become the only available means of showing that the product was not defectively designed. These documents become the evidence that the product underwent balanced and well considered planning, development, testing, quality control, and field testing. The predicted increased involvement of technical writers in the prevention and defense of product liability claims is cited in view of a greater number of cases turning on "failure to warn".

Contraceptive failure rates: new estimates from the 1995 National Survey of Family Growth.

PubMed

Fu, H; Darroch, J E; Haas, T; Ranjit, N

1999-01-01

Unintended pregnancy remains a major public health concern in the United States. Information on pregnancy rates among contraceptive users is needed to guide medical professionals' recommendations and individuals' choices of contraceptive methods. Data were taken from the 1995 National Survey of Family Growth (NSFG) and the 1994-1995 Abortion Patient Survey (APS). Hazards models were used to estimate method-specific contraceptive failure rates during the first six months and during the first year of contraceptive use for all U.S. women. In addition, rates were corrected to take into account the underreporting of induced abortion in the NSFG. Corrected 12-month failure rates were also estimated for subgroups of women by age, union status, poverty level, race or ethnicity, and religion. When contraceptive methods are ranked by effectiveness over the first 12 months of use (corrected for abortion underreporting), the implant and injectables have the lowest failure rates (2-3%), followed by the pill (8%), the diaphragm and the cervical cap (12%), the male condom (14%), periodic abstinence (21%), withdrawal (24%) and spermicides (26%). In general, failure rates are highest among cohabiting and other unmarried women, among those with an annual family income below 200% of the federal poverty level, among black and Hispanic women, among adolescents and among women in their 20s. For example, adolescent women who are not married but are cohabiting experience a failure rate of about 31% in the first year of contraceptive use, while the 12-month failure rate among married women aged 30 and older is only 7%. Black women have a contraceptive failure rate of about 19%, and this rate does not vary by family income; in contrast, overall 12-month rates are lower among Hispanic women (15%) and white women (10%), but vary by income, with poorer women having substantially greater failure rates than more affluent women. Levels of contraceptive failure vary widely by method, as well as by personal and background characteristics. Income's strong influence on contraceptive failure suggests that access barriers and the general disadvantage associated with poverty seriously impede effective contraceptive practice in the United States.

Electromagnetic-Tracked Biopsy under Ultrasound Guidance: Preliminary Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hakime, Antoine, E-mail: thakime@yahoo.com; Deschamps, Frederic; Marques De Carvalho, Enio Garcia

2012-08-15

Purpose: This study was designed to evaluate the accuracy and safety of electromagnetic needle tracking for sonographically guided percutaneous liver biopsies. Methods: We performed 23 consecutive ultrasound-guided liver biopsies for liver nodules with an electromagnetic tracking of the needle. A sensor placed at the tip of a sterile stylet (18G) inserted in a coaxial guiding trocar (16G) used for biopsy was localized in real time relative to the ultrasound imaging plane, thanks to an electromagnetic transmitter and two sensors on the ultrasound probe. This allows for electronic display of the needle tip location and the future needle path overlaid onmore » the real-time ultrasound image. Distance between needle tip position and its electronic display, number of needle punctures, number of needle pull backs for redirection, technical success (needle positioned in the target), diagnostic success (correct histopathology result), procedure time, and complication were evaluated according to lesion sizes, depth and location, operator experience, and 'in-plane' or 'out-of-plane' needle approach. Results: Electronic display was always within 2 mm from the real position of the needle tip. The technical success rate was 100%. A single needle puncture without repuncture was used in all patients. Pull backs were necessary in six patients (26%) to obtain correct needle placement. The overall diagnostic success rate was 91%. The overall true-positive, true-negative, false-negative, and failure rates of the biopsy were 100% (19/19) 100% (2/2), 0% (0/23), and 9% (2/23). The median total procedure time from the skin puncture to the needle in the target was 30 sec (from 5-60 s). Lesion depth and localizations, operator experience, in-plane or out-of-plane approach did not affect significantly the technical, diagnostic success, or procedure time. Even when the tumor size decreased, the procedure time did not increase. Conclusions: Electromagnetic-tracked biopsy is accurate to determine needle tip position and allows fast and accurate needle placement in targeted liver nodules.« less

Transpopliteal stenting of femoral occlusions in patients with critical limb ischemia using a 4-French system.

PubMed

Spreen, Marlon; Vink, Ted; Knippenberg, Bob; Reekers, Jim; van Dijk, Lukas; Wever, Jan; van Eps, Randolph; van Overhagen, Hans

2014-08-01

In many patients with critical limb ischemia (CLI), transfemoral endovascular recanalization is the preferred treatment. Transpopliteal treatment may be used in patients with inaccessible groins. This retrospective study regards transpopliteal stenting of superficial femoral artery (SFA) occlusions using a 4F system. Eleven patients (4 male and 7 female [mean age 77 years]) underwent 12 attempts of transpopliteal recanalization of long SFA occlusions (Trans-Atlantic InterSociety Consensus B through D). All patients had CLI (Rutherford 4 to 6) and were nonoperable due to poor general condition. Indications for transpopliteal access were proximal/flush SFA occlusions (n = 5), failure of antegrade recanalization (n = 4), infected femoral-femoral crossover bypass (n = 2), and occlusion of both the native SFA and the femoral-popliteal bypass (n = 1). The popliteal artery was punctured under ultrasound guidance. Occlusions were recanalized subintimally, and 4F compatible stents were implanted. Technical success rate (<30 % residual stenosis) was achieved in 83 % of cases. In two patients, stent dislocation occurred while the sheath was removed. One arteriovenous fistula was successfully treated with additional stenting. During 6-month follow-up, there were no major amputations, and three patients died from nonrelated causes. Fifty percent of patients alive after 6 months improved to Rutherford score ≤3. The duplex restenosis (>50 %) rate at 6 months was 50 %. Transpopliteal primary stenting of complex SFA lesions in CLI for a temporary bypass is now technically feasible using a 4F system. Technical results are promising. Clinical results after 6 months are acceptable when taking into consideration that this approach may be the last option for limb salvage.

Comparison of Sprint Fidelis and Riata defibrillator lead failure rates.

PubMed

Fazal, Iftikhar A; Shepherd, Ewen J; Tynan, Margaret; Plummer, Christopher J; McComb, Janet M

2013-09-30

Sprint Fidelis and Riata defibrillator leads are prone to early failure. Few data exist on the comparative failure rates and mortality related to lead failure. The aims of this study were to determine the failure rate of Sprint Fidelis and Riata leads, and to compare failure rates and mortality rates in both groups. Patients implanted with Sprint Fidelis leads and Riata leads at a single centre were identified and in July 2012, records were reviewed to ascertain lead failures, deaths, and relationship to device/lead problems. 113 patients had Sprint Fidelis leads implanted between June 2005 and September 2007; Riata leads were implanted in 106 patients between January 2003 and February 2008. During 53.0 ± 22.3 months of follow-up there were 13 Sprint Fidelis lead failures (11.5%, 2.60% per year) and 25 deaths. Mean time to failure was 45.1 ± 15.5 months. In the Riata lead cohort there were 32 deaths, and 13 lead failures (11.3%, 2.71% per year) over 54.8 ± 26.3 months follow-up with a mean time to failure of 53.5 ± 24.5 months. There were no significant differences in the lead failure-free Kaplan-Meier survival curve (p=0.77), deaths overall (p=0.17), or deaths categorised as sudden/cause unknown (p=0.54). Sprint Fidelis and Riata leads have a significant but comparable failure rate at 2.60% per year and 2.71% per year of follow-up respectively. The number of deaths in both groups is similar and no deaths have been identified as being related to lead failure in either cohort. Copyright © 2012. Published by Elsevier Ireland Ltd.

Reliability Growth in Space Life Support Systems

NASA Technical Reports Server (NTRS)

Jones, Harry W.

2014-01-01

A hardware system's failure rate often increases over time due to wear and aging, but not always. Some systems instead show reliability growth, a decreasing failure rate with time, due to effective failure analysis and remedial hardware upgrades. Reliability grows when failure causes are removed by improved design. A mathematical reliability growth model allows the reliability growth rate to be computed from the failure data. The space shuttle was extensively maintained, refurbished, and upgraded after each flight and it experienced significant reliability growth during its operational life. In contrast, the International Space Station (ISS) is much more difficult to maintain and upgrade and its failure rate has been constant over time. The ISS Carbon Dioxide Removal Assembly (CDRA) reliability has slightly decreased. Failures on ISS and with the ISS CDRA continue to be a challenge.

Risk analysis of analytical validations by probabilistic modification of FMEA.

PubMed

Barends, D M; Oldenhof, M T; Vredenbregt, M J; Nauta, M J

2012-05-01

Risk analysis is a valuable addition to validation of an analytical chemistry process, enabling not only detecting technical risks, but also risks related to human failures. Failure Mode and Effect Analysis (FMEA) can be applied, using a categorical risk scoring of the occurrence, detection and severity of failure modes, and calculating the Risk Priority Number (RPN) to select failure modes for correction. We propose a probabilistic modification of FMEA, replacing the categorical scoring of occurrence and detection by their estimated relative frequency and maintaining the categorical scoring of severity. In an example, the results of traditional FMEA of a Near Infrared (NIR) analytical procedure used for the screening of suspected counterfeited tablets are re-interpretated by this probabilistic modification of FMEA. Using this probabilistic modification of FMEA, the frequency of occurrence of undetected failure mode(s) can be estimated quantitatively, for each individual failure mode, for a set of failure modes, and the full analytical procedure. Copyright © 2012 Elsevier B.V. All rights reserved.

Meta 2: Lingua Franca Design and Integration Language

DTIC Science & Technology

2011-08-01

the interest of scientific and technical information exchange, and its publication does not constitute the Government’s approval or disapproval of...buses must be powered in case of no more than 1 failure beyond the Minimum Equipment List (MEL – list of failure combinations that do not affect the...in real systems are rarely plain, but rather they are a complex logical combination of many factors and parameters. The specific processes that

Efficient Probability of Failure Calculations for QMU using Computational Geometry LDRD 13-0144 Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell, Scott A.; Ebeida, Mohamed Salah; Romero, Vicente J.

2015-09-01

This SAND report summarizes our work on the Sandia National Laboratory LDRD project titled "Efficient Probability of Failure Calculations for QMU using Computational Geometry" which was project #165617 and proposal #13-0144. This report merely summarizes our work. Those interested in the technical details are encouraged to read the full published results, and contact the report authors for the status of the software and follow-on projects.

CIDR

Science.gov Websites

this process to the requirements of their study. Data from both reviewed and non-reviewed SNPs will be released. A technical filter will be applied to the non-reviewed SNPs to eliminate total assay failures

Movable bridge maintenance monitoring : [technical summary].

DOT National Transportation Integrated Search

2013-10-01

Maintenance costs for movable bridges are considerably higher than for fixed bridges, mostly because of the complex interaction of mechanical, electrical, and structural components. Malfunction of any component can cause unexpected failure of bridge ...

Subscale Test Methods for Combustion Devices

NASA Technical Reports Server (NTRS)

Anderson, W. E.; Sisco, J. C.; Long, M. R.; Sung, I.-K.

2005-01-01

Stated goals for long-life LRE s have been between 100 and 500 cycles: 1) Inherent technical difficulty of accurately defining the transient and steady state thermochemical environments and structural response (strain); 2) Limited statistical basis on failure mechanisms and effects of design and operational variability; and 3) Very high test costs and budget-driven need to protect test hardware (aversion to test-to-failure). Ambitious goals will require development of new databases: a) Advanced materials, e.g., tailored composites with virtually unlimited property variations; b) Innovative functional designs to exploit full capabilities of advanced materials; and c) Different cycles/operations. Subscale testing is one way to address technical and budget challenges: 1) Prototype subscale combustors exposed to controlled simulated conditions; 2) Complementary to conventional laboratory specimen database development; 3) Instrumented with sensors to measure thermostructural response; and 4) Coupled with analysis

Causes of graft failure in simultaneous pancreas-kidney transplantation by various time periods.

PubMed

Wakil, Kayo; Sugawara, Yasuhiko; Kokudo, Norihiro; Kadowaki, Takashi

2013-01-01

Data collected by the United Network for Organ Sharing from all approved United States transplant programs was analyzed. The data included 26,572 adult diabetic patients who received a primary pancreas transplant between January 1987 and December 2012. Simultaneous pancreas-kidney (SPK) transplantation was the major therapeutic option for diabetes patients. SPK had better graft survival than pancreas transplant alone (PTA) or pancreas-after-kidney (PAK) or pancreas-with-kidney (from a living donor, PWK). The 5-year pancreas graft survival rates for SPK, PWK, PAK, and PTA were 70.0%, 57.2%, 54.0%, and 48.2%, respectively. When long-term SPK pancreas graft survival was examined by various transplant time periods, it was found that survival has remained almost stable since 1996. Graft survival rates were high among the pancreas recipients transplanted in the periods 1996-2000, 2001-2005, and 2006-2012, and the rates were similar: the 5-year rates were 68.9%, 72.4%, and 73.8%, respectively. Technical failure was the leading cause of graft loss during the first year post-transplant, regardless of period: 61.3%, 68.6%, 64.2%, and 71.9% for 1987-1995, 1996-2000, 2001-2005, and 2006-2012, respectively. After one year, chronic rejection was the leading cause of graft loss in all periods: 51.8%, 53.2%, 44.3%, and 40.7% for 1987-1995, 1996-2000, 2001-2005, and 2006-2012, respectively. Chronic rejection accounted for around 50% (or more) of the grafts that survived over five years. Survival of long-term pancreas grafts as well as long-term causes of graft loss remained almost unchanged across the different transplant periods. Clearly, there is a need for a means to identify early markers of chronic rejection, and to control it to improve long-term survival.

International issues in transplantation. Setting the scene and flagging the most urgent and controversial issues.

PubMed

Miranda, B; Matesanz, R

1998-12-30

Organ transplantation is the primary technique for treatment of end-stage organ failure and has benefited more than one million persons world wide. A number of patients have survived for well over 25 years and survival rates at 5 years can be 70% or higher for many organ transplant programs. However, currently more than 40,000 patients are waiting for a kidney, and in western Europe mortality rates for patients waiting for a heart, liver, or lung range from 15 to 30%. The potential need for transplants is even greater and this imbalance between supply and demand creates technical and ethical problems including the risk of organ trafficking. Consequently the number of available organs must be increased. In some cases the organ shortage reflects a true lack of donors, but more often it results from the failure to turn potential into actual donors. The transplant commission of the Council of Europe has just approved a document recommending that member states ensure that all potential donors are identified and as many as possible converted to actual donors. Even with the highest organ donation rate, the indications for organ and tissue transplantation will continue to increase, perpetuating the gap between supply and demand. Organ transplantation, whether living or cadaveric, might be supplemented or replaced by the use of artificial organs, although problems such as power supply, thrombosis, infection, and biocompatibility pose obstacles to long-term function. The use of animals as an alternative source is considered, but so many problems still remain unresolved that xenotransplantation cannot be put forth as a solution at this time. This paper reviews these issues and, citing the Spanish experience, offers strategies to improve the organ donation rate.

Percutaneous Endovascular Salvage Techniques for Implanted Venous Access Device Dysfunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Breault, Stéphane, E-mail: stephane.breault@chuv.ch; Glauser, Frédéric, E-mail: frederic.glauser@chuv.ch; Babaker, Malik, E-mail: malik.babaker@chuv.ch

2015-06-15

PurposeImplanted venous access devices (IVADs) are often used in patients who require long-term intravenous drug administration. The most common causes of device dysfunction include occlusion by fibrin sheath and/or catheter adherence to the vessel wall. We present percutaneous endovascular salvage techniques to restore function in occluded catheters. The aim of this study was to evaluate the feasibility, safety, and efficacy of these techniques.Methods and MaterialsThrough a femoral or brachial venous access, a snare is used to remove fibrin sheath around the IVAD catheter tip. If device dysfunction is caused by catheter adherences to the vessel wall, a new “mechanical adhesiolysis”more » maneuver was performed. IVAD salvage procedures performed between 2005 and 2013 were analyzed. Data included clinical background, catheter tip position, success rate, recurrence, and rate of complication.ResultsEighty-eight salvage procedures were performed in 80 patients, mostly women (52.5 %), with a mean age of 54 years. Only a minority (17.5 %) of evaluated catheters were located at an optimal position (i.e., cavoatrial junction ±1 cm). Mechanical adhesiolysis or other additional maneuvers were used in 21 cases (24 %). Overall technical success rate was 93.2 %. Malposition and/or vessel wall adherences were the main cause of technical failure. No complications were noted.ConclusionThese IVAD salvage techniques are safe and efficient. When a catheter is adherent to the vessel wall, mechanical adhesiolysis maneuvers allow catheter mobilization and a greater success rate with no additional risk. In patients who still require long-term use of their IVAD, these procedures can be performed safely to avoid catheter replacement.« less

The Use of Biodegradable Stents in Malignant Oesophageal Strictures for the Treatment of Dysphagia Before Neoadjuvant Treatment or Radical Radiotherapy: A Feasibility Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krokidis, Miltiadis, E-mail: mkrokidis@hotmail.com; Burke, Chris; Spiliopoulos, Stavros

PurposeTo evaluate the clinical results of the use of biodegradable oesophageal stents in malignant strictures.MethodsEleven patients were included in this prospective analysis in which a woven polydioxanone biodegradable oesophageal stent was used. The inclusion criterion was that the patient underwent neoadjuvant treatment or radical radiotherapy after the stent insertion. Primary end points were dysphagia score at discharge, stent patency, and complication rate. Secondary end points were overall survival and surgical outcome of surgery.ResultsThere was a 100 % procedure technical success rate. Early complications occurred in three patients resulting in failure to restore oral nutrition. In the remaining eight patients, dysphagiamore » was significantly improved at discharge. Mean stent patency rate in this group was 71.5 days. Stent dysfunction occurred in five of eight patients (62.5 %); in two of five patients this was due to local inflammatory reaction, and in three of five patients it was due to tumour growth after a mean time of 97.8 days, and a new metallic stent was consequently placed in four of five patients. One patient was successfully treated with esophagectomy. At the end of follow-up (mean time 102.1 days), three of eight stents were patent. The overall patient survival rate was 81.8 %.ConclusionAlthough short-term dysphagia scores improved, biodegradable stents do not appear to offer a clear beneficial effect in most cases of malignant strictures, particularly due to a local inflammatory reaction that may be induced. Technical improvement of the device and delineation of the patient group that would benefit from its use is necessary if further studies are to be conducted in the future.« less

Transcatheter arterial embolization for endoscopically unmanageable non-variceal upper gastrointestinal bleeding.

PubMed

Lee, Han Hee; Park, Jae Myung; Chun, Ho Jong; Oh, Jung Suk; Ahn, Hyo Jun; Choi, Myung-Gyu

2015-07-01

Transcatheter arterial embolization (TAE) is a therapeutic option for endoscopically unmanageable upper gastrointestinal (GI) bleeding. We aimed to assess the efficacy and clinical outcomes of TAE for acute non-variceal upper GI bleeding and to identify predictors of recurrent bleeding within 30 days. Visceral angiography was performed in 66 patients (42 men, 24 women; mean age, 60.3 ± 12.7 years) who experienced acute non-variceal upper GI bleeding that failed to be controlled by endoscopy during a 7-year period. Clinical information was reviewed retrospectively. Outcomes included technical success rates, complications, and 30-day rebleeding and mortality rates. TAE was feasible in 59 patients. The technical success rate was 98%. Rebleeding within 30 days was observed in 47% after an initial TAE and was managed with re-embolization in 8, by endoscopic intervention in 5, by surgery in 2, and by conservative care in 12 patients. The 30-day overall mortality rate was 42.4%. In the case of initial endoscopic hemostasis failure (n = 34), 31 patients underwent angiographic embolization, which was successful in 30 patients (96.8%). Rebleeding occurred in 15 patients (50%), mainly because of malignancy. Two factors were independent predictors of rebleeding within 30 days by multivariate analysis: coagulopathy (odds ratio [OR] = 4.37; 95% confidence interval [CI]: 1.25-15.29; p = 0.021) and embolization in ≥2 territories (OR = 4.93; 95% CI: 1.43-17.04; p = 0.012). Catheterization-related complications included hepatic artery dissection and splenic embolization. TAE controlled acute non-variceal upper GI bleeding effectively. TAE may be considered when endoscopic therapy is unavailable or unsuccessful. Correction of coagulopathy before TAE is recommended.

Minimally Invasive Implantable Fetal Micropacemaker: Mechanical Testing and Technical Refinements

PubMed Central

Zhou, Li; Vest, Adriana N.; Peck, Raymond A.; Sredl, Jonathan P.; Huang, Xuechen; Bar-Cohen, Yaniv; Silka, Michael J.; Pruetz, Jay D.; Chmait, Ramen H.; Loeb, Gerald E.

2016-01-01

This paper discusses the technical and safety requirements for cardiac pacing of a human fetus with heart failure and hydrops fetalis secondary to complete heart block. Engineering strategies to meet specific technical requirements were integrated into a systematic design and implementation consisting of a novel fetal micropacemaker, a percutaneous implantation system, and a sterile package that enables device storage and recharging maintenance in a clinical setting. We further analyzed observed problems on myocardial fixation and pacing lead fatigue previously reported in earlier preclinical trials. This paper describes the technical refinements of the implantable fetal micropacemaker to overcome these challenges. The mechanical performance has been extensively tested to verify the improvement of reliability and safety margins of the implantation system. PMID:27021067

Evaluation of possible prognostic factors for the success, survival, and failure of dental implants.

PubMed

Geckili, Onur; Bilhan, Hakan; Geckili, Esma; Cilingir, Altug; Mumcu, Emre; Bural, Canan

2014-02-01

To analyze the prognostic factors that are associated with the success, survival, and failure rates of dental implants. Data including implant sizes, insertion time, implant location, and prosthetic treatment of 1656 implants have been collected, and the association of these factors with success, survival, and failure of implants was analyzed. The success rate was lower for short and maxillary implants. The failure rate of maxillary implants exceeded that of mandibular implants, and the failure rate of implants that were placed in the maxillary anterior region was significantly higher than other regions. The failure rates of implants that were placed 5 years ago or more were higher than those that were placed later. Anterior maxilla is more critical for implant loss than other sites. Implants in the anterior mandible show better success compared with other locations, and longer implants show better success rates. The learning curve of the clinician influences survival and success rates of dental implants.

Does Bruxism Contribute to Dental Implant Failure? A Systematic Review and Meta-Analysis.

PubMed

Zhou, Yi; Gao, Jinxia; Luo, Le; Wang, Yining

2016-04-01

Bruxism was usually considered as a contraindication for oral implanting. The causal relationship between bruxism and dental implant failure was remained controversial in existing literatures. This meta-analysis was performed to investigate the relationship between them. This review conducted an electronic systematic literature search in MEDLINE (PubMed) and EmBase in November 2013 without time and language restrictions. Meanwhile, a hand searching for all the relevant references of included studies was also conducted. Study information extraction and methodological quality assessments were accomplished by two reviewers independently. A discussion ensued if any disagreement occurred, and unresolved issues were solved by consulting a third reviewer. Methodological quality was assessed by using the Newcastle-Ottawa Scale tool. Odds ratio (OR) with 95% confidence interval (CI) was pooled to estimate the relative effect of bruxism on dental implant failures. Fixed effects model was used initially; if the heterogeneity was high, random effects model was chosen for meta-analysis. Statistical analyses were carried out by using Review Manager 5.1. In this meta-analysis review, extracted data were classified into two groups based on different units. Units were based on the number of prostheses (group A) and the number of patients (group B). In group A, the total pooled OR of bruxers versus nonbruxers for all subgroups was 4.72 (95% CI: 2.66-8.36, p = .07). In group B, the total pooled OR of bruxers versus nonbruxers for all subgroups was 3.83 (95% CI: 2.12-6.94, p = .22). This meta-analysis was performed to evaluate the relationship between bruxism and dental implant failure. In contrast to nonbruxers, prostheses in bruxers had a higher failure rate. It suggests that bruxism is a contributing factor of causing the occurrence of dental implant technical/biological complications and plays a role in dental implant failure. © 2015 Wiley Periodicals, Inc.

Continuous spinal drain following endoscopic third ventriculostomy: a proposal to change the definition of failure.

PubMed

Ozisik, Pinar; Roth, Jonathan; Beni-Adani, Liana; Constantini, Shlomi

2011-11-01

This study evaluates the safety, efficacy, and indications for continuous lumbar drainage (CLD) in patients following endoscopic third ventriculostomy (ETV). We retrospectively reviewed the clinical data of 22 consecutive patients treated between 1996 and 2010 with CLD after ETV. The decision to insert a CLD was made in selected patients only. CLD was inserted in cases of high measured intracranial pressure (12 patients), clinical symptoms indicative of continuing hydrocephalus (2 patients), and "prophylactically" in 8 patients, based either on the clinical condition of patients before ETV or on technical difficulties during the ETV procedure, which seemed to increase the risk of ETV failure. CLD insertion took place either in the operating room immediately following the ETV procedure or under very specific conditions and with close patient monitoring in an ICU setting. Only four patients eventually required shunting, all within 1 month after ETV. Therefore, the overall ETV success rate was 81.8% (18/22 patients). Of the 14 patients suffering from measured or clinically observed continuing hydrocephalus, 12 (85%) ultimately recovered without the need for a permanent shunt. Without the CLD, some of these patients would probably have been declared "failures" and referred for a standard shunt. CLD provided a time window following ETV for the absorption system to recover and return to full functionality. Selective usage of CLD is a reasonable and safe method to gain time and possibly facilitates the recovery of absorption capacity following ETV. CLD should be considered before conceding a post-ETV patient as a failure.

Failure rate and reliability of the KOMATSU hydraulic excavator in surface limestone mine

NASA Astrophysics Data System (ADS)

Harish Kumar N., S.; Choudhary, R. P.; Murthy, Ch. S. N.

2018-04-01

The model with failure rate function of bathtub-shaped is helpful in reliability analysis of any system and particularly in reliability associated privative maintenance. The usual Weibull distribution is, however, not capable to model the complete lifecycle of the any with a bathtub-shaped failure rate function. In this paper, failure rate and reliability analysis of the KOMATSU hydraulic excavator/shovel in surface mine is presented and also to improve the reliability and decrease the failure rate of each subsystem of the shovel based on the preventive maintenance. The model of the bathtub-shaped for shovel can also be seen as a simplification of the Weibull distribution.

Chapter 11. Fuel Economy: The Case for Market Failure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greene, David L; German, John; Delucchi, Mark A

2009-01-01

The efficiency of energy using durable goods, from automobiles to home air conditioners, is not only a key determinant of economy-wide energy use but also of greenhouse gas (GHG) emissions, climate change and energy insecurity. Energy analysts have long noted that consumers appear to have high implicit discount rates for future fuel savings when choosing among energy using durable goods (Howarth and Sanstad, 1995). In modeling consumers choices of appliances, the Energy Information Administration (EIA) has used discount rates of 30 percent for heating systems, 69 percent for choice of refrigerator and up to 111 percent for choice of watermore » heater (U.S. DOE/EIA, 1996). Several explanations have been offered for this widespread phenomenon, including asymmetric information, bounded rationality and transaction costs. This chapter argues that uncertainty combined with loss aversion by consumers is sufficient to explain the failure to adopt cost effective energy efficiency improvements in the market for automotive fuel economy, although other market failures appear to be present as well. Understanding how markets for energy efficiency function is crucial to formulating effective energy policies (see Pizer, 2006). Fischer et al., (2004), for example, demonstrated that if consumers fully value the discounted present value of future fuel savings, fuel economy standards are largely redundant and produce small welfare losses. However, if consumers value only the first three years of fuel savings, then fuel economy standards can significantly increase consumer welfare. The nature of any market failure that might be present in the market for energy efficiency would also affect the relative efficacy of energy taxes versus regulatory standards (CBO, 2003). If markets function efficiently, energy taxes would generally be more efficient than regulatory standards in increasing energy efficiency and reducing energy use. If markets are decidedly inefficient, standards would likely be more effective. The chapter explores the roles of uncertainty and loss-aversion in the market for automotive fuel economy. The focus is on the determination of the technical efficiency of the vehicle rather than consumers choices among vehicles. Over the past three decades, changes in the mix of vehicles sold has played little if any role in raising the average fuel economy of new light-duty vehicles from 13 miles per gallon (mpg) in 1975 to 21 mpg today (Heavenrich, 2006). Over that same time period, average vehicle weight is up 2 percent, horsepower is up 60 percent, passenger car interior volume increased by 2 percent and the market share of light trucks grew by 31 percentage points. Historically, at least, increasing light-duty vehicle fuel economy in the United States has been a matter of manufacturers decisions to apply technology to increase the technical efficiency of cars and light trucks. Understanding how efficiently the market determines the technical fuel economy of new vehicles would seem to be critical to formulating effective policies to encourage future fuel economy improvement. The central issue is whether or not the market for fuel economy is economically efficient. Rubenstein (1998) lists the key assumptions of the rational economic decision model. The decision maker must have a clear picture of the choice problem he or she faces. He should be fully aware of the set of alternatives from which to choose and have the skill necessary to make complicated calculations needed to discover the optimal course of action. Finally, the decision maker should have the unlimited ability to calculate and be indifferent to alternatives and choice sets.« less

VLSI (Very Large Scale Integrated Circuits) Device Reliability Models.

DTIC Science & Technology

1984-12-01

CIRCUIT COMPLEXITY FAILURE RATES FOR... A- 40 MOS SSI/MSI DEVICES IN FAILURE PER 106 HOURS TABLE 5.1.2.5-19: C1 AND C2 CIRCUIT COMPLEXITY FAILURE RATES FOR...A- 40 MOS SSI/MSI DEVICES IN FAILURE PER 106 HOURS TABLE 5.1.2.5-19: Cl AND C2 CIRCUIT COMPLEXITY FAILURE RATES FOR... A-41 LINEAR DEVICES IN...19 National Semiconductor 20 Nitron 21 Raytheon 22 Sprague 23 Synertek 24 Teledyne Crystalonics 25 TRW Semiconductor 26 Zilog The following companies

Pancreas transplantation. An initial experience with systemic and portal drainage of pancreatic allografts.

PubMed Central

Rosenlof, L K; Earnhardt, R C; Pruett, T L; Stevenson, W C; Douglas, M T; Cornett, G C; Hanks, J B

1992-01-01

Pancreas transplantation has evolved dramatically since its introduction in 1966. As new centers for transplantation have developed, the evaluation of complications associated with pancreas transplantation has led to advances in surgical technique. Furthermore, surgical alterations of the pancreas resulting from transplantation (systemic release of insulin and denervation) are of unproven consequence on glucose metabolism. Since 1988, the authors have performed 21 transplants (16 combined pancreas/kidney, 3 pancreas alone, which includes 1 retransplantation, 1 pancreas after previous kidney transplant, and 1 "cluster") in 20 patients aged 18 to 49 years; mean, 35 +/- 1 years. Overall patient survival is 95%. Three pancreatic grafts failed within the first year because of technical failure; one additional pancreas was lost to an immunologic event on postoperative day 449, for an overall pancreatic graft survival of 81%. No renal grafts were lost. To evaluate causes of graft failure, demographic data were compared, which included age and sex of the donor and the recipient, operative time, intraoperative blood transfusion, and ischemic time of the graft. No statistically significant differences were found between groups except for ischemic time (11.7 +/- 6.4 hours for the technical success group versus 19.8 +/- 3.7 hours for the technical failure group; p less than 0.05 by unpaired Student's t test). Quadruple immunosuppression was used, which included prednisone, cyclosporine, azathioprine, and antilymphoblast globulin. A mean of 1.2 (range, 0 to 3) rejection episodes per patient occurred. Mean hospital stay was 24 +/- 11 days. Surgical and infectious complications were evaluated by comparing the technical success (TS) group (n = 17) with the technical failure (TF) group. Surgical complications in the TS group revealed a mean of 1.3 episodes per patient, whereas the TF group had 3.7 episodes per patient. The TS also had a reduced incidence of infectious complications compared with the TF (1.7 versus 4.3 episodes per patient). Cytomegalovirus was common in both groups, accounting for 11 infectious episodes, and occurred on a mean postoperative day of 38. Mean postoperative HbA1C levels dropped to 5 +/- 1% from 11 +/- 3%. The authors developed a new technique that incorporates portal drainage of the pancreatic venous effluent in three recipients. Preoperative metabolic studies disclosed a mean fasting glucose of 211 +/- 27 mg/dL and a mean stimulated glucose value of 434 +/- 41 mg/dL for all patients; the mean fasting insulin was 23 +/- 4 microU/mL.(ABSTRACT TRUNCATED AT 400 WORDS) Images FIG. 5. PMID:1632680

Quantitative modeling of failure propagation in intelligent transportation systems.

DOT National Transportation Integrated Search

2014-08-01

Unmanned vehicles are projected to reach consumer use within this decade - related legislation has already passed in California. The : most significant technical challenge associated with these vehicles is their integration in transportation environm...

Markov and semi-Markov processes as a failure rate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grabski, Franciszek

2016-06-08

In this paper the reliability function is defined by the stochastic failure rate process with a non negative and right continuous trajectories. Equations for the conditional reliability functions of an object, under assumption that the failure rate is a semi-Markov process with an at most countable state space are derived. A proper theorem is presented. The linear systems of equations for the appropriate Laplace transforms allow to find the reliability functions for the alternating, the Poisson and the Furry-Yule failure rate processes.

Laparoscopic repair of giant paraesophageal hernia: are there factors associated with anatomic recurrence?

PubMed

Antiporda, Michael; Veenstra, Benjamin; Jackson, Chloe; Kandel, Pujan; Daniel Smith, C; Bowers, Steven P

2018-02-01

Repair of giant paraesophageal hernia (PEH) is associated with a favorably high rate of symptom improvement; however, rates of recurrence by objective measures remain high. Herein we analyze our experience with laparoscopic giant PEH repair to determine what factors if any can predict anatomic recurrence. We prospectively collected data on PEH characteristics, variations in operative techniques, and surgeon factors for 595 patients undergoing laparoscopic PEH repair from 2008 to 2015. Upper GI study was performed at 6 months postoperatively and selectively thereafter-any supra-diaphragmatic stomach was considered hiatal hernia recurrence. Exclusion criteria included revisional operation (22.4%), size <5 cm (17.6%), inadequate follow-up (17.8%), and confounding concurrent operations (6.9%). Inclusion criteria were met by 202 patients (31% male, median age 71 years, and median BMI 28.7). At a median follow-up of 6 months (IQR 6-12), overall anatomic recurrence rate was 34.2%. Symptom recurrence rate was 9.9% and revisional operation was required in ten patients (4.9%). Neither patient demographics nor PEH characteristics (size, presence of Cameron erosions, esophagitis, or Barrett's) correlated with anatomic recurrence. Technical factors at operation (mobilized intra-abdominal length of esophagus, Collis gastroplasty, number of anterior/posterior stitches, use of crural buttress, use of pledgeted or mattress sutures, or gastrostomy) were also not correlated with recurrence. Regarding surgeon factors, annual volume of fewer than ten cases per year was associated with increased risk of anatomic failure (54 vs 33%, P = 0.02). Multivariate analysis identified surgeon experience (<10 cases per year) as an independent factor associated with early hiatal hernia recurrence (OR 3.7, 95% CI 1.34-10.9). Laparoscopic repair of giant PEH is associated with high anatomic recurrence rate but excellent symptom control. PEH characteristics and technical operative variables do not appear to significantly affect rates of recurrence. In contrast, surgeon volume does appear to contribute significantly to durability of repair.

Veno-arterial extracorporeal membrane oxygenation for adult cardiovascular failure.

PubMed

Pellegrino, Vincent; Hockings, Lisen E; Davies, Andrew

2014-10-01

To examine the utility and technical challenges of applying veno-arterial extracorporeal membrane oxygenation for acute cardiovascular failure in adults with acute and chronic causes of heart failure. The role of mechanical circulatory support in acute cardiovascular continues to evolve as technology and clinical experience develop. There is increasing interest in the role of veno-arterial extracorporeal membrane oxygenation as a bridging therapy and as an adjunct to conventional cardiopulmonary resuscitation. Veno-arterial extracorporeal membrane oxygenation is an expensive, complex, resource intensive support. It is essential that its future use be guided by evidence obtained from centres that have demonstrated timely, safe support.

Spacecraft Parachute Recovery System Testing from a Failure Rate Perspective

NASA Technical Reports Server (NTRS)

Stewart, Christine E.

2013-01-01

Spacecraft parachute recovery systems, especially those with a parachute cluster, require testing to identify and reduce failures. This is especially important when the spacecraft in question is human-rated. Due to the recent effort to make spaceflight affordable, the importance of determining a minimum requirement for testing has increased. The number of tests required to achieve a mature design, with a relatively constant failure rate, can be estimated from a review of previous complex spacecraft recovery systems. Examination of the Apollo parachute testing and the Shuttle Solid Rocket Booster recovery chute system operation will clarify at which point in those programs the system reached maturity. This examination will also clarify the risks inherent in not performing a sufficient number of tests prior to operation with humans on-board. When looking at complex parachute systems used in spaceflight landing systems, a pattern begins to emerge regarding the need for a minimum amount of testing required to wring out the failure modes and reduce the failure rate of the parachute system to an acceptable level for human spaceflight. Not only a sufficient number of system level testing, but also the ability to update the design as failure modes are found is required to drive the failure rate of the system down to an acceptable level. In addition, sufficient data and images are necessary to identify incipient failure modes or to identify failure causes when a system failure occurs. In order to demonstrate the need for sufficient system level testing prior to an acceptable failure rate, the Apollo Earth Landing System (ELS) test program and the Shuttle Solid Rocket Booster Recovery System failure history will be examined, as well as some experiences in the Orion Capsule Parachute Assembly System will be noted.

A risk assessment methodology to evaluate the risk failure of managed aquifer recharge in the Mediterranean Basin

NASA Astrophysics Data System (ADS)

Rodríguez-Escales, Paula; Canelles, Arnau; Sanchez-Vila, Xavier; Folch, Albert; Kurtzman, Daniel; Rossetto, Rudy; Fernández-Escalante, Enrique; Lobo-Ferreira, João-Paulo; Sapiano, Manuel; San-Sebastián, Jon; Schüth, Christoph

2018-06-01

Managed aquifer recharge (MAR) can be affected by many risks. Those risks are related to different technical and non-technical aspects of recharge, like water availability, water quality, legislation, social issues, etc. Many other works have acknowledged risks of this nature theoretically; however, their quantification and definition has not been developed. In this study, the risk definition and quantification has been performed by means of fault trees and probabilistic risk assessment (PRA). We defined a fault tree with 65 basic events applicable to the operation phase. After that, we have applied this methodology to six different managed aquifer recharge sites located in the Mediterranean Basin (Portugal, Spain, Italy, Malta, and Israel). The probabilities of the basic events were defined by expert criteria, based on the knowledge of the different managers of the facilities. From that, we conclude that in all sites, the perception of the expert criteria of the non-technical aspects were as much or even more important than the technical aspects. Regarding the risk results, we observe that the total risk in three of the six sites was equal to or above 0.90. That would mean that the MAR facilities have a risk of failure equal to or higher than 90 % in the period of 2-6 years. The other three sites presented lower risks (75, 29, and 18 % for Malta, Menashe, and Serchio, respectively).

Methods and Costs to Achieve Ultra Reliable Life Support

NASA Technical Reports Server (NTRS)

Jones, Harry W.

2012-01-01

A published Mars mission is used to explore the methods and costs to achieve ultra reliable life support. The Mars mission and its recycling life support design are described. The life support systems were made triply redundant, implying that each individual system will have fairly good reliability. Ultra reliable life support is needed for Mars and other long, distant missions. Current systems apparently have insufficient reliability. The life cycle cost of the Mars life support system is estimated. Reliability can be increased by improving the intrinsic system reliability, adding spare parts, or by providing technically diverse redundant systems. The costs of these approaches are estimated. Adding spares is least costly but may be defeated by common cause failures. Using two technically diverse systems is effective but doubles the life cycle cost. Achieving ultra reliability is worth its high cost because the penalty for failure is very high.

Causes of Coal Mine Accidents in the World and Turkey.

PubMed

Küçük, Filiz Çağla Uyanusta; Ilgaz, Aslıhan

2015-04-01

Occupational accidents and occupational diseases are common in the mining sector in Turkey and throughout the world. The most common causes of accidents in coal mining are firedamp and dust explosions, landslips, mine fires, and technical failures related to transport and mechanization. An analysis of occupational accidents in the consideration of social and economic factors will let understand the real causes behind these accidents, which are said to happen inevitably due to technical deficiencies or failures. Irregular working conditions, based on profit maximization and cost minimization, are related to strategic operational preferences and public policies. Proving that accidents in mines, where occupational health and safety measures are not implemented and inspections are not done properly or at all, are caused by the fact that production is imposed to be carried out in the fastest, cheapest, and most profitable way will allow us to take steps to prevent further mine accidents.

Causes of Coal Mine Accidents in the World and Turkey

PubMed Central

Küçük, Filiz Çağla Uyanusta; Ilgaz, Aslıhan

2015-01-01

Occupational accidents and occupational diseases are common in the mining sector in Turkey and throughout the world. The most common causes of accidents in coal mining are firedamp and dust explosions, landslips, mine fires, and technical failures related to transport and mechanization. An analysis of occupational accidents in the consideration of social and economic factors will let understand the real causes behind these accidents, which are said to happen inevitably due to technical deficiencies or failures. Irregular working conditions, based on profit maximization and cost minimization, are related to strategic operational preferences and public policies. Proving that accidents in mines, where occupational health and safety measures are not implemented and inspections are not done properly or at all, are caused by the fact that production is imposed to be carried out in the fastest, cheapest, and most profitable way will allow us to take steps to prevent further mine accidents. PMID:29404108

Medical therapy is best for atherosclerotic renal artery stenosis: Arguments for.

PubMed

Annigeri, R A

2012-01-01

Atherosclerotic renal artery stenosis (ARAS) is a common condition that causes hypertension and reduction in the glomerular filtration rate and is an independent risk factor for death. Despite high technical success, the clinical benefit of renal artery (RA) angioplasty with stenting in ARAS remains doubtful. The published randomized clinical trials provide no support for the notion that renal angioplasty with stenting significantly improves blood pressure, preserves renal function, or reduces episodes of congestive heart failure in patients with ARAS. RA stenting is associated with procedure-related morbidity and mortality. Agents to block the renin-angiotensin-aldosterone system improve outcome and should be a part of a multifaceted medical regimen in ARAS. Medical therapy effectively controls atherosclerotic renovascular disease at all levels of vasculature and hence is the best therapy for ARAS.

Waste Generator Instructions: Key to Successful Implementation of the US DOE's 435.1 for Transuranic Waste Packaging Instructions (LA-UR-12-24155) - 13218

DOE Office of Scientific and Technical Information (OSTI.GOV)

French, David M.; Hayes, Timothy A.; Pope, Howard L.

In times of continuing fiscal constraints, a management and operation tool that is straightforward to implement, works as advertised, and virtually ensures compliant waste packaging should be carefully considered and employed wherever practicable. In the near future, the Department of Energy (DOE) will issue the first major update to DOE Order 435.1, Radioactive Waste Management. This update will contain a requirement for sites that do not have a Waste Isolation Pilot Plant (WIPP) waste certification program to use two newly developed technical standards: Contact-Handled Defense Transuranic Waste Packaging Instructions and Remote-Handled Defense Transuranic Waste Packaging Instructions. The technical standards aremore » being developed from the DOE O 435.1 Notice, Contact-Handled and Remote-Handled Transuranic Waste Packaging, approved August 2011. The packaging instructions will provide detailed information and instruction for packaging almost every conceivable type of transuranic (TRU) waste for disposal at WIPP. While providing specificity, the packaging instructions leave to each site's own discretion the actual mechanics of how those Instructions will be functionally implemented at the floor level. While the Technical Standards are designed to provide precise information for compliant packaging, the density of the information in the packaging instructions necessitates a type of Rosetta Stone that translates the requirements into concise, clear, easy to use and operationally practical recipes that are waste stream and facility specific for use by both first line management and hands-on operations personnel. The Waste Generator Instructions provide the operator with step-by-step instructions that will integrate the sites' various operational requirements (e.g., health and safety limits, radiological limits or dose limits) and result in a WIPP certifiable waste and package that can be transported to and emplaced at WIPP. These little known but widely productive Waste Generator Instructions (WGIs) have been used occasionally in the past at large sites for treatment and packaging of TRU waste. The WGIs have resulted in highly efficient waste treatment, packaging and certification for disposal of TRU waste at WIPP. For example, a single WGI at LANL, combined with an increase in gram loading, resulted in a mind boggling 6,400% increase in waste loading for {sup 238}Pu heat source waste. In fact, the WGI combined with a new Contact Handled (CH) TRU Waste Content (TRUCON) Code provided a massive increase in shippable wattage per Transuranic Package Transporter-II (TRUPACT-II) over the previously used and more restrictive TRUCON Code that have been used previously for the heat source waste. In fact, the use of the WGI process at LANL's TA-55 facility reduced non-compliant drums for WIPP certification and disposal from a 13% failure rate down to a 0.5% failure rate and is expected to further reduce the failure rate to zero drums per year. The inherent value of the WGI is that it can be implemented in a site's current procedure issuance process and it provides documented proof of what actions were taken for each waste stream packaged. The WGI protocol provides a key floor-level operational component to achieve goal alignment between actual site operations, the WIPP TRU waste packaging instructions, and DOE O 435.1. (authors)« less

Control of Technology Transfer at JPL

NASA Technical Reports Server (NTRS)

Oliver, Ronald

2006-01-01

Controlled Technology: 1) Design: preliminary or critical design data, schematics, technical flow charts, SNV code/diagnostics, logic flow diagrams, wirelist, ICDs, detailed specifications or requirements. 2) Development: constraints, computations, configurations, technical analyses, acceptance criteria, anomaly resolution, detailed test plans, detailed technical proposals. 3) Production: process or how-to: assemble, operated, repair, maintain, modify. 4) Manufacturing: technical instructions, specific parts, specific materials, specific qualities, specific processes, specific flow. 5) Operations: how-to operate, contingency or standard operating plans, Ops handbooks. 6) Repair: repair instructions, troubleshooting schemes, detailed schematics. 7) Test: specific procedures, data, analysis, detailed test plan and retest plans, detailed anomaly resolutions, detailed failure causes and corrective actions, troubleshooting, trended test data, flight readiness data. 8) Maintenance: maintenance schedules and plans, methods for regular upkeep, overhaul instructions. 9) Modification: modification instructions, upgrades kit parts, including software

Transcatheter Arterial Embolization for Gastrointestinal Bleeding Associated with Gastric Carcinoma: Prognostic Factors Predicting Successful Hemostasis and Survival.

PubMed

Park, Sangik; Shin, Ji Hoon; Gwon, Dong-Il; Kim, Hyoung Jung; Sung, Kyu-Bo; Yoon, Hyun-Ki; Ko, Gi-Young; Ko, Heung Kyu

2017-07-01

To evaluate outcomes of transcatheter arterial embolization (TAE) for gastric cancer-related gastrointestinal (GI) bleeding and factors associated with successful TAE and improved survival after TAE. This retrospective study included 43 patients (34 men; age 60.6 y ± 13.6) with gastric cancer-related GI bleeding undergoing angiography between January 2000 and December 2015. Clinical course, laboratory findings, and TAE characteristics were reviewed. Technical success of TAE was defined as target area devascularization, and clinical success was defined as bleeding cessation with hemodynamic stability during 72 hours after TAE. Student t test was used for comparison of continuous variables, and Fisher exact test was used for categorical variables. Univariate and multivariate analysis were performed to identify predictors of successful TAE and 30-day survival after TAE. TAE was performed in 40 patients. Technical and clinical success rates of TAE were 85.0% and 65.0%, respectively. Splenic infarction occurred in 2 patients as a minor complication. Rebleeding after TAE occurred in 7 patients. Death related to bleeding occurred in 5 patients. Active bleeding (P = .044) and higher transfusion requirement (3.3 U ± 2.6 vs 1.8 U ± 1.7; P = .039) were associated with TAE failure. Successful TAE predicted improved 30-day survival after TAE on univariate and multivariate analysis (P = .018 and P = .022; odds ratio, 0.132). TAE for gastric cancer-associated GI bleeding may be a lifesaving procedure. Severe bleeding with a higher transfusion requirement and active bleeding on angiography predicted TAE failure. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

How and why of orthodontic bond failures: An in vivo study

PubMed Central

Vijayakumar, R. K.; Jagadeep, Raju; Ahamed, Fayyaz; Kanna, Aprose; Suresh, K.

2014-01-01

Introduction: The bonding of orthodontic brackets and their failure rates by both direct and in-direct procedures are well-documented in orthodontic literature. Over the years different adhesive materials and various indirect bonding transfer procedures have been compared and evaluated for bond failure rates. The aim of our study is to highlight the use of a simple, inexpensive and ease of manipulation of a single thermo-plastic transfer tray and the use the of a single light cure adhesive to evaluate the bond failure rates in clinical situations. Materials and Methods: A total of 30 patients were randomly divided into two groups (Group A and Group B). A split-mouth study design was used, for, both the groups so that they were distributed equally with-out bias. After initial prophylaxis, both the procedures were done as per manufactures instructions. All patients were initially motivated and reviewed for bond failures rates for 6 months. Results: Bond failure rates were assessed for over-all direct and indirect procedures, anterior and posterior arches, and for individual tooth. Z-test was used for statistically analyzing, the normal distribution of the sample in a spilt mouth study. The results of the two groups were compared and P value was calculated using Z-proportion test to assess the significance of the bond failure. Conclusion: Over-all bond failure was more for direct bonding. Anterior bracket failure was more in-direct bonding than indirect procedure, which showed more posterior bracket failures. In individual tooth bond failure, mandibular incisor, and premolar brackets showed more failure, followed by maxillary premolars and canines. PMID:25210392

Does the United States economy affect heart failure readmissions? A single metropolitan center analysis.

PubMed

Thompson, Keith A; Morrissey, Ryan P; Phan, Anita; Schwarz, Ernst R

2012-08-01

To determine the effects of the US economy on heart failure hospitalization rates. The recession was associated with worsening unemployment, loss of private insurance and prescription medication benefits, medication nonadherence, and ultimately increased rates of hospitalization for heart failure. We compared hospitalization rates at a large, single, academic medical center from July 1, 2006 to February 28, 2007, a time of economic stability, and July 1, 2008 to February 28, 2009, a time of economic recession in the United States. Significantly fewer patients had private medical insurance during the economic recession than during the control period (36.5% vs 46%; P = 0.04). Despite this, there were no differences in the heart failure hospitalization or readmission rates, length of hospitalization, need for admission to an intensive care unit, in-hospital mortality, or use of guideline-recommended heart failure medications between the 2 study periods. We conclude that despite significant effects on medical insurance coverage, rates of heart failure hospitalization at our institution were not significantly affected by the recession. Additional large-scale population-based research is needed to better understand the effects of fluctuations in the US economy on heart failure hospitalization rates. © 2012 Wiley Periodicals, Inc.

Surveillance of in vivo resistance of Plasmodium falciparum to antimalarial drugs from 1992 to 1999 in Malabo (Equatorial Guinea).

PubMed

Roche, Jesús; Guerra-Neira, Ana; Raso, José; Benito, Agustîn

2003-05-01

From 1992-1999, we have assessed the therapeutic efficacy of three malaria treatment regimens (chloroquine 25 mg/kg over three days, pyrimethamine/sulfadoxine 1.25/25 mg/kg in one dose, and quinine 25-30 mg/kg daily in three oral doses over a four-, five-, or seven-day period) in 1,189 children under age 10 at Malabo Regional Hospital in Equatorial Guinea. Of those children, 958 were followed up clinically and parasitologically for 14 days. With chloroquine, the failure rate varied from 55% in 1996 to 40% in 1999; the early treatment failure rate increased progressively over the years, from 6% in 1992 to 30% in 1999. With pyrimethamine/sulfadoxine, the failure rate varied from 0% in 1996 to 16% in 1995. The short quinine treatment regimens used in 1992 and 1993 (4 and 5 days, respectively) resulted in significantly higher failure rates (19% and 22%, respectively) than the 7d regimen (3-5.5%). We conclude that: a) failure rates for chloroquine are in the change period (> 25%), and urgent action is needed; b) pyrimethamine/ sulfadoxine failure rates are in the alert period (6-15%), and surveillance must be continued; and c) quinine failure rates are in the grace period (< 6%), so quinine can be recommended.

A study of Mariner 10 flight experiences and some flight piece part failure rate computations

NASA Technical Reports Server (NTRS)

Paul, F. A.

1976-01-01

The problems and failures encountered in Mariner flight are discussed and the data available through a quantitative accounting of all electronic piece parts on the spacecraft are summarized. It also shows computed failure rates for electronic piece parts. It is intended that these computed data be used in the continued updating of the failure rate base used for trade-off studies and predictions for future JPL space missions.

Heart Rate Dynamics During A Treadmill Cardiopulmonary Exercise Test in Optimized Beta-Blocked Heart Failure Patients

PubMed Central

Carvalho, Vitor Oliveira; Guimarães, Guilherme Veiga; Ciolac, Emmanuel Gomes; Bocchi, Edimar Alcides

2008-01-01

BACKGROUND Calculating the maximum heart rate for age is one method to characterize the maximum effort of an individual. Although this method is commonly used, little is known about heart rate dynamics in optimized beta-blocked heart failure patients. AIM The aim of this study was to evaluate heart rate dynamics (basal, peak and % heart rate increase) in optimized beta-blocked heart failure patients compared to sedentary, normal individuals (controls) during a treadmill cardiopulmonary exercise test. METHODS Twenty-five heart failure patients (49±11 years, 76% male), with an average LVEF of 30±7%, and fourteen controls were included in the study. Patients with atrial fibrillation, a pacemaker or noncardiovascular functional limitations or whose drug therapy was not optimized were excluded. Optimization was considered to be 50 mg/day or more of carvedilol, with a basal heart rate between 50 to 60 bpm that was maintained for 3 months. RESULTS Basal heart rate was lower in heart failure patients (57±3 bpm) compared to controls (89±14 bpm; p<0.0001). Similarly, the peak heart rate (% maximum predicted for age) was lower in HF patients (65.4±11.1%) compared to controls (98.6±2.2; p<0.0001). Maximum respiratory exchange ratio did not differ between the groups (1.2±0.5 for controls and 1.15±1 for heart failure patients; p=0.42). All controls reached the maximum heart rate for their age, while no patients in the heart failure group reached the maximum. Moreover, the % increase of heart rate from rest to peak exercise between heart failure (48±9%) and control (53±8%) was not different (p=0.157). CONCLUSION No patient in the heart failure group reached the maximum heart rate for their age during a treadmill cardiopulmonary exercise test, despite the fact that the percentage increase of heart rate was similar to sedentary normal subjects. A heart rate increase in optimized beta-blocked heart failure patients during cardiopulmonary exercise test over 65% of the maximum age-adjusted value should be considered an effort near the maximum. This information may be useful in rehabilitation programs and ischemic tests, although further studies are required. PMID:18719758

Early outcomes of thoracic endovascular stent-graft repair for acute complicated type B dissection using the Gore TAG endoprosthesis.

PubMed

Pearce, Benjamin J; Passman, Marc A; Patterson, Mark A; Taylor, Steve M; Lecroy, Christopher J; Combs, Bart R; Jordan, William D

2008-11-01

We assessed the technical success and early outcome of thoracic endovascular aortic repair (TEVAR) for complicated acute type B thoracic aortic dissection treated at a single institution using a commercially available device. All patients with symptomatic complicated acute type B thoracic aortic dissection treated with TEVAR since Food and Drug Administration approval of the Gore (Flagstaff, AZ) TAG endoprosthesis were identified from a prospectively maintained vascular registry. Clinical indications, operative technique, perioperative complications, follow-up imaging, and mortality were analyzed. Between March 2005 and November 2007, 127 TEVARs using the TAG endoprosthesis were performed, of which 15 (11.8%) were for complicated acute type B thoracic aortic dissection. Indications for repair were malperfusion (53%), persistent pain (27%), and primary aortic failure (33%). Technical feasibility and success with deployment proximal to the entry tear was 93.3%, requiring at least partial coverage of the left subclavian artery in seven (46.7%). Adjunctive procedures required at the time of TEVAR included renal stent (n = 2), iliac stent (n = 3), and access-artery open repair (n = 2). Twelve patients (80%) had immediate resolution of the malperfusion deficit. Major perioperative complications included paraplegia (13.3%), renal failure requiring hemodialysis (13.3%), and stroke (6.7%). Perioperative mortality was 13.3%, occurring in one patient presenting with rupture and one with profound heart failure on admission. For complicated acute type B thoracic aortic dissection, TEVAR using commercially available stent grafts showed high technical success, excellent results at resolving malperfusion, and acceptably low complications and perioperative mortality.

Adapting an Agent-Based Model of Socio-Technical Systems to Analyze Security Failures

DTIC Science & Technology

2016-10-17

total number of non-blackouts differed from the total number in the baseline data to a statistically significant extent with a p- valueɘ.0003...the total number of non-blackouts differed from the total number in the baseline data to a statistically significant extent with a p-valueɘ.0003...I. Nikolic, and Z. Lukszo, Eds., Agent-based modelling of socio-technical systems. Springer Science & Business Media, 2013, vol. 9. [12] A. P. Shaw

The impact of vaccine failure rate on epidemic dynamics in responsive networks.

PubMed

Liang, Yu-Hao; Juang, Jonq

2015-04-01

An SIS model based on the microscopic Markov-chain approximation is considered in this paper. It is assumed that the individual vaccination behavior depends on the contact awareness, local and global information of an epidemic. To better simulate the real situation, the vaccine failure rate is also taken into consideration. Our main conclusions are given in the following. First, we show that if the vaccine failure rate α is zero, then the epidemic eventually dies out regardless of what the network structure is or how large the effective spreading rate and the immunization response rates of an epidemic are. Second, we show that for any positive α, there exists a positive epidemic threshold depending on an adjusted network structure, which is only determined by the structure of the original network, the positive vaccine failure rate and the immunization response rate for contact awareness. Moreover, the epidemic threshold increases with respect to the strength of the immunization response rate for contact awareness. Finally, if the vaccine failure rate and the immunization response rate for contact awareness are positive, then there exists a critical vaccine failure rate αc > 0 so that the disease free equilibrium (DFE) is stable (resp., unstable) if α < αc (resp., α > αc). Numerical simulations to see the effectiveness of our theoretical results are also provided.

Demographic processes limiting seedling recruitment in arid grassland restoration

Treesearch

Jeremy J. James; Tony J. Svejcar; Matthew J. Rinella

2011-01-01

Seeding is an important management tool in aridland restoration, but seeded species often fail to establish. Previous research has largely focused on the technical aspects of seeding with little effort directed at identifying demographic processes driving recruitment failures.

Evaluation of lignin as an antioxidant in asphalt binders and bituminous mixtures : technical summary.

DOT National Transportation Integrated Search

2017-01-01

The chemical process of oxidative age-hardening in asphalt pavements is one of the major distresses leading to hot mix asphalt (HMA) pavement failure as evidenced by fatigue and thermal (low temperature) cracking.

28 CFR 301.309 - In-person hearing before the committee.

Code of Federal Regulations, 2011 CFR

2011-07-01

... time set for that hearing, show good cause for failure to appear. (b) In conducting the hearing, the Committee is not bound by common law or statutory rules of evidence, or by technical or formal rules of...

28 CFR 301.309 - In-person hearing before the committee.

Code of Federal Regulations, 2010 CFR

2010-07-01

... time set for that hearing, show good cause for failure to appear. (b) In conducting the hearing, the Committee is not bound by common law or statutory rules of evidence, or by technical or formal rules of...

Prevention of Roller Bearing-Initiated Burnoffs in Railroad Freight Car Journals

DOT National Transportation Integrated Search

1979-01-01

The objective of this program was to determine the technical feasibility and cost effectiveness of constructing three separate devices for the prevention of catastrophic roller bearing-initiated, railroad journal failure. 1. Construction of a low cos...

Laboratory investigations into fracture propagation characteristics of rock material

NASA Astrophysics Data System (ADS)

Prasad, B. N. V. Siva; Murthy, V. M. S. R.

2018-04-01

After Industrial Revolution, demand of materials for building up structures have increased enormously. Unfortunately, failures of such structures resulted in loss of life and property. Rock is anisotropic and discontinuous in nature with inherent flaws or so-called discontinuities in it. Rock is apparently used for construction in mining, civil, tunnelling, hydropower, geothermal and nuclear sectors [1]. Therefore, the strength of the structure built up considering rockmass as the construction material needs proper technical evaluation during designing stage itself to prevent and predict the scenarios of catastrophic failures due to these inherent fractures [2]. In this study, samples collected from nine different drilling sites have been investigated in laboratory for understanding the fracture propagation characteristics in rock. Rock material properties, ultrasonic velocities through pulse transmission technique and Mode I Fracture Toughness Testing of different variants of Dolomites and Graywackes are determined in laboratory and the resistance of the rock material to catastrophic crack extension or propagation has been determined. Based on the Fracture Toughness values and the rock properties, critical Energy Release Rates have been estimated. However further studies in this direction is to be carried out to understand the fracture propagation characteristics in three-dimensional space.

Fetal transesophageal echocardiography: clinical introduction as a monitoring tool during cardiac intervention in a human fetus.

PubMed

Kohl, T; Müller, A; Tchatcheva, K; Achenbach, S; Gembruch, U

2005-12-01

Because of insufficient imaging by maternal transabdominal fetal echocardiography (TAE) in a human fetus with aortic atresia, imperforate atrial septum and progressive cardiac failure, we assessed the feasibility of fetal transesophageal echocardiography (TEE) as a monitoring tool during fetal cardiac intervention at 24 + 6 weeks of gestation. Percutaneous fetoscopic intraesophageal deployment of the ultrasound catheter was achieved and did not result in any maternal or fetal complications. Fetal TEE permitted substantially clearer definition of fetal cardiac anatomy and intracardiac device manipulations than conventional maternal TAE. Despite the employment of various devices, no sufficiently large opening could be achieved within the atrial septum. Although the fetus tolerated the procedure remarkably well and satisfactory fetoplacental flow could be documented at the end of the procedure, the fetus died from progressive cardiac failure 3 days after the intervention. Fetoscopic TEE is feasible in the human fetus and permits substantially clearer definition of fetal cardiac anatomy and intracardiac manipulations than conventional maternal TAE. Based on the observation of spontaneous closure of multiple iatrogenic perforations of the atrial septum, specialized devices are required in order to improve the technical success rate of septoplasty methods and hence the survival odds of these high-risk patients.

Capital projects: Egypt case study. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lieberson, J.; Stallard, J.

1994-03-01

This report assesses the US Agency for International Development`s (A.I.D.`s) capital assistance program in Egypt in terms of both its commercial benefits for the United States and its developmental benefits for Egypt. In regard to the first aspect, the study found that few A.I.D.-funded projects or studies generated either participation by other donors or follow-on sales for U.S. companies. The report places much of the blame for this on U.S. firms` failure to take advantage of a clear opportunity to develop the Egyptian commercial market. Findings regarding the developmental benefits of the projects are mixed. (1) The projects helped supportmore » strong private sector growth in Egypt through the 1980`s. Nonetheless, their economic and financial rates of return were generally disappointing. (2) The projects were built to a high technical standard, but their sustainability is in doubt. (3) The pursuit of commercial advantage for U.S. firms did not distort the developmental goals of the projects. Overall, the report attributes the disappointing economic results of A.I.D.`s capital assistance program to a poor policy environment, which the reforms pursued in connection with the program did little to change.« less

Achieving the Proper Balance Between Crew and Public Safety

NASA Technical Reports Server (NTRS)

Gowan, John; Rosati, Paul; Silvestri, Ray; Stahl, Ben; Wilde, Paul

2011-01-01

A paramount objective of all human-rated launch and reentry vehicle developers is to ensure that the risks to both the crew onboard and the public are minimized within reasonable cost, schedule, and technical constraints. Past experience has shown that proper attention to range safety requirements necessary to ensure public safety must be given early in the design phase to avoid additional operational complexities or threats to the safety of people onboard. This paper will outline the policy considerations, technical issues, and operational impacts regarding launch and reentry vehicle failure scenarios where crew and public safety are intertwined and thus addressed optimally in an integrated manner. Historical examples and lessons learned from both the Space Shuttle and Constellation Programs will be presented. Using these examples as context, the paper will discuss some operational, design, and analysis approaches to mitigate and balance the risks to people onboard and in the public. Manned vehicle perspectives from the FAA and Air Force organizations that oversee public safety will also be summarized. Finally, the paper will emphasize the need to factor policy, operational, and analysis considerations into the early design trades of new vehicles to help ensure that both crew and public safety are maximized to the greatest extent possible.

Sterilization failures in Singapore: an examination of ligation techniques and failure rates.

PubMed

Cheng, M C; Wong, Y M; Rochat, R W; Ratnam, S S

1977-04-01

The University Department of Obstetrics and Gynecology, Kandang Kerbau Hospital in Singapore, initiated a study in early 1974 of failure rates for various methods of sterilization and the factors responsible for the failures. During the period January 1974 to March 1976, 51 cases of first pregnancy following ligation were discovered. Cumulative failure rates at 24 months were 0.34 per 100 women for abdominal sterilization, 1.67 for culdoscopic, 3.12 for vaginal, and 4.49 for laparoscopic procedures. Findings for 35 patients who underwent religation showed that recanalization and the establishment of a fistulous opening caused the majority of failures. Clearly, more effective methods of tubal occlusion in sterilization are needed.

Payload maintenance cost model for the space telescope

NASA Technical Reports Server (NTRS)

White, W. L.

1980-01-01

An optimum maintenance cost model for the space telescope for a fifteen year mission cycle was developed. Various documents and subsequent updates of failure rates and configurations were made. The reliability of the space telescope for one year, two and one half years, and five years were determined using the failure rates and configurations. The failure rates and configurations were also used in the maintenance simulation computer model which simulate the failure patterns for the fifteen year mission life of the space telescope. Cost algorithms associated with the maintenance options as indicated by the failure patterns were developed and integrated into the model.

Rate of change of heart size before congestive heart failure in dogs with mitral regurgitation.

PubMed

Lord, P; Hansson, K; Kvart, C; Häggström, J

2010-04-01

The objective of the study was to examine the changes in vertebral heart scale, and left atrial and ventricular dimensions before and at onset of congestive heart failure in cavalier King Charles spaniels with mitral regurgitation. Records and radiographs from 24 cavalier King Charles spaniels with mitral regurgitation were used. Vertebral heart scale (24 dogs), and left atrial dimension and left ventricular end diastolic and end systolic diameters (18 dogs) and their rate of increase were measured at intervals over years to the onset of congestive heart failure. They were plotted against time to onset of congestive heart failure. Dimensions and rates of change of all parameters were highest at onset of congestive heart failure, the difference between observed and chance outcome being highly significant using a two-tailed chi-square test (P<0.001). The left heart chambers increase in size rapidly only in the last year before the onset of congestive heart failure. Increasing left ventricular end systolic dimension is suggestive of myocardial failure before the onset of congestive heart failure. Rate of increase of heart dimensions may be a useful indicator of impending congestive heart failure.

Direct Adaptive Control of Systems with Actuator Failures: State of the Art and Continuing Challenges

NASA Technical Reports Server (NTRS)

Tao, Gang; Joshi, Suresh M.

2008-01-01

In this paper, the problem of controlling systems with failures and faults is introduced, and an overview of recent work on direct adaptive control for compensation of uncertain actuator failures is presented. Actuator failures may be characterized by some unknown system inputs being stuck at some unknown (fixed or varying) values at unknown time instants, that cannot be influenced by the control signals. The key task of adaptive compensation is to design the control signals in such a manner that the remaining actuators can automatically and seamlessly take over for the failed ones, and achieve desired stability and asymptotic tracking. A certain degree of redundancy is necessary to accomplish failure compensation. The objective of adaptive control design is to effectively use the available actuation redundancy to handle failures without the knowledge of the failure patterns, parameters, and time of occurrence. This is a challenging problem because failures introduce large uncertainties in the dynamic structure of the system, in addition to parametric uncertainties and unknown disturbances. The paper addresses some theoretical issues in adaptive actuator failure compensation: actuator failure modeling, redundant actuation requirements, plant-model matching, error system dynamics, adaptation laws, and stability, tracking, and performance analysis. Adaptive control designs can be shown to effectively handle uncertain actuator failures without explicit failure detection. Some open technical challenges and research problems in this important research area are discussed.

Heart failure and atrial fibrillation: current concepts and controversies.

PubMed Central

Van den Berg, M. P.; Tuinenburg, A. E.; Crijns, H. J.; Van Gelder, I. C.; Gosselink, A. T.; Lie, K. I.

1997-01-01

Heart failure and atrial fibrillation are very common, particularly in the elderly. Owing to common risk factors both disorders are often present in the same patient. In addition, there is increasing evidence of a complex, reciprocal relation between heart failure and atrial fibrillation. Thus heart failure may cause atrial fibrillation, with electromechanical feedback and neurohumoral activation playing an important mediating role. In addition, atrial fibrillation may promote heart failure; in particular, when there is an uncontrolled ventricular rate, tachycardiomyopathy may develop and thereby heart failure. Eventually, a vicious circle between heart failure and atrial fibrillation may form, in which neurohumoral activation and subtle derangement of rate control are involved. Treatment should aim at unloading of the heart, adequate control of ventricular rate, and correction of neurohumoral activation. Angiotensin converting enzyme inhibitors may help to achieve these goals. Treatment should also include an attempt to restore sinus rhythm through electrical cardioversion, though appropriate timing of cardioversion is difficult. His bundle ablation may be used to achieve adequate rate control in drug refractory cases. PMID:9155607

75 FR 5784 - Guidance on Preparation of Market-Based Rate Filings and Electric Quarterly Reports by Public...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-04

... Preparation of Market-Based Rate Filings and Electric Quarterly Reports by Public Utilities; Notice of Technical Conference January 28, 2010. Take notice that Commission staff will convene a technical conference... final agenda of the technical conference. The March 3, 2010 technical conference will focus on the...

Clinical review: Helmet and non-invasive mechanical ventilation in critically ill patients.

PubMed

Esquinas Rodriguez, Antonio M; Papadakos, Peter J; Carron, Michele; Cosentini, Roberto; Chiumello, Davide

2013-04-25

Non-invasive mechanical ventilation (NIV) has proved to be an excellent technique in selected critically ill patients with different forms of acute respiratory failure. However, NIV can fail on account of the severity of the disease and technical problems, particularly at the interface. The helmet could be an alternative interface compared to face mask to improve NIV success. We performed a clinical review to investigate the main physiological and clinical studies assessing the efficacy and related issues of NIV delivered with a helmet. A computerized search strategy of MEDLINE/PubMed (January 2000 to May 2012) and EMBASE (January 2000 to May 2012) was conducted limiting the search to retrospective, prospective, nonrandomized and randomized trials. We analyzed 152 studies from which 33 were selected, 12 physiological and 21 clinical (879 patients). The physiological studies showed that NIV with helmet could predispose to CO₂ rebreathing and increase the patients' ventilator asynchrony. The main indications for NIV were acute cardiogenic pulmonary edema, hypoxemic acute respiratory failure (community-acquired pneumonia, postoperative and immunocompromised patients) and hypercapnic acute respiratory failure. In 9 of the 21 studies the helmet was compared to a face mask during either continous positive airway pressure or pressure support ventilation. In eight studies oxygenation was similar in the two groups, while the intubation rate was similar in four and lower in three studies for the helmet group compared to face mask group. The outcome was similar in six studies. The tolerance was better with the helmet in six of the studies. Although these data are limited, NIV delivered by helmet could be a safe alternative to the face mask in patients with acute respiratory failure.

Simulation Assisted Risk Assessment: Blast Overpressure Modeling

NASA Technical Reports Server (NTRS)

Lawrence, Scott L.; Gee, Ken; Mathias, Donovan; Olsen, Michael

2006-01-01

A probabilistic risk assessment (PRA) approach has been developed and applied to the risk analysis of capsule abort during ascent. The PRA is used to assist in the identification of modeling and simulation applications that can significantly impact the understanding of crew risk during this potentially dangerous maneuver. The PRA approach is also being used to identify the appropriate level of fidelity for the modeling of those critical failure modes. The Apollo launch escape system (LES) was chosen as a test problem for application of this approach. Failure modes that have been modeled and/or simulated to date include explosive overpressure-based failure, explosive fragment-based failure, land landing failures (range limits exceeded either near launch or Mode III trajectories ending on the African continent), capsule-booster re-contact during separation, and failure due to plume-induced instability. These failure modes have been investigated using analysis tools in a variety of technical disciplines at various levels of fidelity. The current paper focuses on the development and application of a blast overpressure model for the prediction of structural failure due to overpressure, including the application of high-fidelity analysis to predict near-field and headwinds effects.

Transcatheter Arterial Embolization for Gastrointestinal Bleeding Secondary to Gastrointestinal Lymphoma.

PubMed

Zheng, Lin; Shin, Ji Hoon; Han, Kichang; Tsauo, Jiaywei; Yoon, Hyun-Ki; Ko, Gi-Young; Shin, Jong-Soo; Sung, Kyu-Bo

2016-11-01

To evaluate the effectiveness of transcatheter arterial embolization (TAE) for gastrointestinal (GI) bleeding caused by GI lymphoma. The medical records of 11 patients who underwent TAE for GI bleeding caused by GI lymphoma between 2001 and 2015 were reviewed retrospectively. A total of 20 TAE procedures were performed. On angiography, contrast extravasation, and both contrast extravasation and tumor staining were seen in 95 % (19/20) and 5 % (1/20) of the procedures, respectively. The most frequently embolized arteries were jejunal (n = 13) and ileal (n = 5) branches. Technical and clinical success rates were 100 % (20/20) and 27 % (3/11), respectively. The causes of clinical failure in eight patients were rebleeding at new sites. In four patients who underwent repeat angiography, the bleeding focus was new each time. Three patients underwent small bowel resection due to rebleeding after one (n = 2) or four (n = 1) times of TAEs. Another two patients underwent small bowel resection due to small bowel ischemia/perforation after three or four times of TAEs. The 30-day mortality rate was 18 % due to hypovolemic shock (n = 1) and multiorgan failure (n = 1). Angiogram with TAE shows limited therapeutic efficacy to manage GI lymphoma-related bleeding due to high rebleeding at new sites. Although TAE can be an initial hemostatic measure, surgery should be considered for rebleeding due to possible bowel ischemic complication after repeated TAE procedures.

Technical results and effects of operator experience on uterine artery embolization for fibroids: the Ontario Uterine Fibroid Embolization Trial.

PubMed

Pron, Gaylene; Bennett, John; Common, Andrew; Sniderman, Kenneth; Asch, Murray; Bell, Stuart; Kozak, Roman; Vanderburgh, Leslie; Garvin, Greg; Simons, Martin; Tran, Cuong; Kachura, John

2003-05-01

To document the technical results and spectrum of practice of uterine artery embolization (UAE) for fibroids in the health care setting in Canada. The effects of interventional radiologist's (IR's) experience with UAE on procedure and fluoroscopy time were also investigated. The study involved a multicenter prospective single-arm clinical treatment trial and included the practices of 11 IRs at eight university-affiliated teaching and community hospitals. Vascular access with percutaneous femoral artery approach was followed by transcatheter delivery of polyvinyl alcohol (PVA) particles into uterine arteries with fluoroscopic guidance. Technical success, complications, procedural time, fluoroscopy time, and effects of operator experience were outcomes analyzed. Between November 1998 and November 2000, 570 embolization procedures were performed in 555 patients. UAE was bilaterally successful in 97% (95% CI: 95%-98%). Variant anatomy was the most common reason for failure to embolize bilaterally. The procedural complication rate was 5.3% (95% CI: 3.6%-7.4%). Of the 30 events, three involved major complications (one seizure and two allergic reactions) that resulted in additional care or extended hospital stay. Procedure time and fluoroscopy time averaged 61 minutes (95% CI; 58-63 minutes) and 18.9 minutes (95% CI; 18-19.8) and varied significantly among IRs (P <.001; P <.001). The average 27% reduction in procedure time (20 minutes; P <.001) and 24% reduction in fluoroscopy time (5.1 minutes; P <.001) with increasing UAE experience were significant. A high level of technical success with few complications was obtained with a variety of operators in diverse practice settings. Increased experience in UAE significantly reduced procedure and fluoroscopy time.

5 CFR 1204.21 - Submission.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND PROCEDURES AVAILABILITY OF OFFICIAL INFORMATION Appeals § 1204.21 Submission. (a) A person may appeal the following actions, or failure to act by... technically not possible to reproduce electronically maintained information in the requester's preferred...

5 CFR 1204.21 - Submission.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND PROCEDURES AVAILABILITY OF OFFICIAL INFORMATION Appeals § 1204.21 Submission. (a) A person may appeal the following actions, or failure to act by... technically not possible to reproduce electronically maintained information in the requester's preferred...

5 CFR 1204.21 - Submission.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND PROCEDURES AVAILABILITY OF OFFICIAL INFORMATION Appeals § 1204.21 Submission. (a) A person may appeal the following actions, or failure to act by... technically not possible to reproduce electronically maintained information in the requester's preferred...

5 CFR 1204.21 - Submission.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND PROCEDURES AVAILABILITY OF OFFICIAL INFORMATION Appeals § 1204.21 Submission. (a) A person may appeal the following actions, or failure to act by... technically not possible to reproduce electronically maintained information in the requester's preferred...

5 CFR 1204.21 - Submission.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND PROCEDURES AVAILABILITY OF OFFICIAL INFORMATION Appeals § 1204.21 Submission. (a) A person may appeal the following actions, or failure to act by... technically not possible to reproduce electronically maintained information in the requester's preferred...

POLICY CONUNDRUM: RESTORING WILD SALMON TO THE PACIFIC NORTHWEST

EPA Science Inventory

Restoring wild salmon runs to the Pacific Northwest is technically challenging, politically nasty, and socially divisive. Past restoration efforts have been largely unsuccessful. Society's failure to reverse the continuing decline of wild salmon has the characteristics of a pol...

Analytical Chemistry Laboratory

NASA Technical Reports Server (NTRS)

Anderson, Mark

2013-01-01

The Analytical Chemistry and Material Development Group maintains a capability in chemical analysis, materials R&D failure analysis and contamination control. The uniquely qualified staff and facility support the needs of flight projects, science instrument development and various technical tasks, as well as Cal Tech.

Three-dimensional path planning software-assisted transjugular intrahepatic portosystemic shunt: a technical modification.

PubMed

Tsauo, Jiaywei; Luo, Xuefeng; Ye, Linchao; Li, Xiao

2015-06-01

This study was designed to report our results with a modified technique of three-dimensional (3D) path planning software assisted transjugular intrahepatic portosystemic shunt (TIPS). 3D path planning software was recently developed to facilitate TIPS creation by using two carbon dioxide portograms acquired at least 20° apart to generate a 3D path for overlay needle guidance. However, one shortcoming is that puncturing along the overlay would be technically impossible if the angle of the liver access set and the angle of the 3D path are not the same. To solve this problem, a prototype 3D path planning software was fitted with a utility to calculate the angle of the 3D path. Using this, we modified the angle of the liver access set accordingly during the procedure in ten patients. Failure for technical reasons occurred in three patients (unsuccessful wedged hepatic venography in two cases, software technical failure in one case). The procedure was successful in the remaining seven patients, and only one needle pass was required to obtain portal vein access in each case. The course of puncture was comparable to the 3D path in all patients. No procedure-related complication occurred following the procedures. Adjusting the angle of the liver access set to match the angle of the 3D path determined by the software appears to be a favorable modification to the technique of 3D path planning software assisted TIPS.

Model analysis of the link between interest rates and crashes

NASA Astrophysics Data System (ADS)

Broga, Kristijonas M.; Viegas, Eduardo; Jensen, Henrik Jeldtoft

2016-09-01

We analyse the effect of distinct levels of interest rates on the stability of the financial network under our modelling framework. We demonstrate that banking failures are likely to emerge early on under sustained high interest rates, and at much later stage-with higher probability-under a sustained low interest rate scenario. Moreover, we demonstrate that those bank failures are of a different nature: high interest rates tend to result in significantly more bankruptcies associated to credit losses whereas lack of liquidity tends to be the primary cause of failures under lower rates.

The influence of mandibular skeletal characteristics on inferior alveolar nerve block anesthesia.

PubMed

You, Tae Min; Kim, Kee-Deog; Huh, Jisun; Woo, Eun-Jung; Park, Wonse

2015-09-01

The inferior alveolar nerve block (IANB) is the most common anesthetic techniques in dentistry; however, its success rate is low. The purpose of this study was to determine the correlation between IANB failure and mandibular skeletal characteristics. In total, 693 cases of lower third molar extraction (n = 575 patients) were examined in this study. The ratio of the condylar and coronoid distances from the mandibular foramen (condyle-coronoid ratio [CC ratio]) was calculated, and the mandibular skeleton was then classified as normal, retrognathic, or prognathic. The correlation between IANB failure and sex, treatment side, and the CC ratio was assessed. The IANB failure rates for normal, retrognathic, and prognathic mandibles were 7.3%, 14.5%, and 9.5%, respectively, and the failure rate was highest among those with a CC ratio < 0.8 (severe retrognathic mandible). The failure rate was significantly higher in the retrognathic group than in normal group (P = 0.019), and there was no statistically significant difference between the other two groups. IANB failure could be attributable, in part, to the skeletal characteristics of the mandible. In addition, the failure rate was found to be significantly higher in the retrognathic group.

The influence of mandibular skeletal characteristics on inferior alveolar nerve block anesthesia

PubMed Central

You, Tae Min; Kim, Kee-Deog; Huh, Jisun; Woo, Eun-Jung

2015-01-01

Background The inferior alveolar nerve block (IANB) is the most common anesthetic techniques in dentistry; however, its success rate is low. The purpose of this study was to determine the correlation between IANB failure and mandibular skeletal characteristics Methods In total, 693 cases of lower third molar extraction (n = 575 patients) were examined in this study. The ratio of the condylar and coronoid distances from the mandibular foramen (condyle-coronoid ratio [CC ratio]) was calculated, and the mandibular skeleton was then classified as normal, retrognathic, or prognathic. The correlation between IANB failure and sex, treatment side, and the CC ratio was assessed. Results The IANB failure rates for normal, retrognathic, and prognathic mandibles were 7.3%, 14.5%, and 9.5%, respectively, and the failure rate was highest among those with a CC ratio < 0.8 (severe retrognathic mandible). The failure rate was significantly higher in the retrognathic group than in normal group (P = 0.019), and there was no statistically significant difference between the other two groups. Conclusions IANB failure could be attributable, in part, to the skeletal characteristics of the mandible. In addition, the failure rate was found to be significantly higher in the retrognathic group. PMID:28879267

Role of paediatric assist device in bridge to transplant

PubMed Central

Hetzer, Roland; Javier, Mariano Francisco del Maria

2018-01-01

Background While heart transplantation has gained recognition as the gold standard therapy for advanced heart failure, the scarcity of donor organs has become an important concern. The evolution of surgical alternatives such as ventricular assist devices (VADs), allow for recovery of the myocardium and ensure patient survival until heart transplantation becomes possible. This report elaborates the role of VADs as a bridge to heart transplantation in infants and children (≤18 years old) with end-stage heart failure. Methods A retrospective review of the medical records of 201 heart transplant recipients between May 1986 and September 2014 identified 78 children [38.8%; mean age 7.2 (7.8±6.0) years old; IQR: 2.6–11.8 years] with advanced heart failure who were supported with a VAD [left VAD (LVAD) =21; biventricular VAD (BVAD) =57] as a bridge to heart transplantation. Fourteen (17.9%) patients were less than 1 year old; 15 (19.2%) children had a cardiac arrest and underwent cardiopulmonary resuscitation, with 7 of these patients also requiring extracorporeal membrane oxygenation (ECMO) support prior to implantation of a VAD. The aetiology of heart failure was primarily cardiomyopathy (dilative, restrictive from endocardial fibrosis, idiopathic or toxic-induced), reported in 56 (71.8%) patients. The VADs employed were primarily Berlin Heart EXCOR® (n=63), HeartWare (n=13), Berlin Heart INCOR® (n=1), and Toyobo (n=1). Results Mean duration of VAD support was 59 (133.37±191.57) days (range, 1–945 days; IQR: 23–133 days) before a donor heart became available. The primary complication encountered while patients were being bridged to transplant was mediastinal bleeding (7.8%). The main indication for pump exchanges was thrombus formation in the valves. There was no incidence of technical failure of the blood pump or driving system components. Skin infections around the cannulae occurred in 2.5%. Adverse neurological symptoms (thromboembolism 11.1%, cerebral haemorrhage 3.6%) that occurred did not have any permanent neurological sequelae that could be detected on clinical examination in this study. Mean duration of follow-up was 9.4 (10.3±7.6) years (IQR: 3.74–15.14 years). Cumulative survival rates of patients bridged to transplantation with VAD were 93.6%±2.8%, 84.6%±4.1%, 79.1%±4.7%, 63.8%±6.2%, 61.6%±7.1%, and 52.1%±9.3% at 30 days, 1, 5, 10, 15 and 20 years, respectively. There was no statistically significant difference (P=0.79) in survival rates of patients bridged to heart transplantation with VAD compared to those who underwent primary heart transplantation. Post-transplant survival rates stratified according to the type of VAD implanted and number of ventricles supported were not statistically different (P=0.93 and 0.73, respectively). In addition, post-transplant survival rates were not significantly different when age, gender and diagnosis were adjusted for. Furthermore, no statistically significant difference was found when post-transplant survival rates of children who had episodes of rejection were compared to those who did not have episodes of rejection. Conclusions The results in this series demonstrate that VADs satisfactorily support paediatric patients with advanced heart failure from a variety of aetiologies until heart transplantation. The data further suggests that patients bridged with VADs have comparable long-term post-transplant survival as those undergoing primary heart transplantation. PMID:29492386

[Do laymen understand information about hospital quality? An empirical verification using risk-adjusted mortality rates as an example].

PubMed

Sander, Uwe; Kolb, Benjamin; Taheri, Fatemeh; Patzelt, Christiane; Emmert, Martin

2017-11-01

The effect of public reporting to improve quality in healthcare is reduced by the limited intelligibility of information about the quality of healthcare providers. This may result in worse health-related choices especially for older people and those with lower levels of education. There is, as yet, little information as to whether laymen understand the concepts behind quality comparisons and if this comprehension is correlated with hospital choices. An instrument with 20 items was developed to analyze the intelligibility of five technical terms which were used in German hospital report cards to explain risk-adjusted death rates. Two online presentations of risk-adjusted death rates for five hospitals in the style of hospital report cards were developed. An online survey of 353 volunteers tested the comprehension of the risk-adjusted mortality rates and included an experimental hospital choice. The intelligibility of five technical terms was tested: risk-adjusted, actual and expected death rate, reference range and national average. The percentages of correct answers for the five technical terms were in the range of 75.0-60.2%. Between 23.8% and 5.1% of the respondents were not able to answer the question about the technical term itself. The least comprehensible technical terms were "risk-adjusted death rate" and "reference range". The intelligibility of the 20 items that were used to test the comprehension of the risk-adjusted mortality was between 89.5% and 14.2%. The two items that proved to be least comprehensible were related to the technical terms "risk-adjusted death rate" and "reference range". For all five technical terms it was found that a better comprehension correlated significantly with better hospital choices. We found a better than average intelligibility for the technical terms "actual and expected death rate" and for "national average". The least understandable were "risk-adjusted death rate" and "reference range". Since the self-explanatory technical terms "actual and expected death rate" and "national average" are easy to understand and the comprehension is correlated with hospitals choices, we recommend using them for the presentation of measures which contain risk-adjusted mortality. The technical terms "risk-adjusted death rate" and "reference range" should stay in the background, since comprehension problems can be expected and explanations would have to be provided. Copyright © 2017. Published by Elsevier GmbH.

Revisional surgery after failed esophagogastric myotomy for achalasia: successful esophageal preservation.

PubMed

Veenstra, Benjamin R; Goldberg, Ross F; Bowers, Steven P; Thomas, Mathew; Hinder, Ronald A; Smith, C Daniel

2016-05-01

Treatment failure with recurrent dysphagia after Heller myotomy occurs in fewer than 10 % of patients, most of whom will seek repeat surgical intervention. These reoperations are technically challenging, and as such, there exist only limited reports of reoperation with esophageal preservation. We retrospectively reviewed the records of patients who sought operative intervention from March 1998 to December 2014 for obstructed swallowing after esophagogastric myotomy. All patients underwent a systematic approach, including complete hiatal dissection, takedown of prior fundoplication, and endoscopic assessment of myotomy. Patterns of failure were categorized as: fundoplication failure, inadequate myotomy, fibrosis, and mucosal stricture. A total of 58 patients underwent 65 elective reoperations. Four patients underwent esophagectomy as their initial reoperation, while three patients ultimately required esophagectomy. The remainder underwent reoperations with the goal of esophageal preservation. Of these 58, 46 were first-time reoperations; ten were second time; and two were third-time reoperations. Forty-one had prior operations via a trans-abdominal approach, 11 via thoracic approach, and 6 via combined approaches. All reoperations at our institution were performed laparoscopically (with two conversions to open). Inadequate myotomy was identified in 53 % of patients, fundoplication failure in 26 %, extensive fibrosis in 19 %, and mucosal stricture in 2 %. Intraoperative esophagogastric perforation occurred in 19 % of patients and was repaired. Our postoperative leak rate was 5 %. Esophageal preservation was possible in 55 of the 58 operations in which it was attempted. At median follow-up of 34 months, recurrent dysphagia after reoperation was seen in 63 % of those with a significant fibrosis versus 28 % with inadequate myotomy, 25 % with failed wrap, and 100 % with mucosal stricture (p = 0.10). Laparoscopic reoperation with esophageal preservation is successful in the majority of patients with recurrent dysphagia after Heller myotomy. The pattern of failure has implications for relief of dysphagia with reoperative intervention.

A quantitative model of honey bee colony population dynamics.

PubMed

Khoury, David S; Myerscough, Mary R; Barron, Andrew B

2011-04-18

Since 2006 the rate of honey bee colony failure has increased significantly. As an aid to testing hypotheses for the causes of colony failure we have developed a compartment model of honey bee colony population dynamics to explore the impact of different death rates of forager bees on colony growth and development. The model predicts a critical threshold forager death rate beneath which colonies regulate a stable population size. If death rates are sustained higher than this threshold rapid population decline is predicted and colony failure is inevitable. The model also predicts that high forager death rates draw hive bees into the foraging population at much younger ages than normal, which acts to accelerate colony failure. The model suggests that colony failure can be understood in terms of observed principles of honey bee population dynamics, and provides a theoretical framework for experimental investigation of the problem.

Lessons for surgeons in the final moments of Air France Flight 447.

PubMed

Bhangu, Aneel; Bhangu, Sonia; Stevenson, James; Bowley, Douglas M

2013-06-01

All surgeons make mistakes, and learning from critical incidents may help improve performance. The present study aimed to highlight lessons for surgeons from analysis of the final moments of Air France Flight 447. All of the authors work in teams and situations where safety, technical performance, and non-technical skills are critical. This review was born out of discussions regarding the events of Flight 447; specifically, whether the airline disaster was relevant to their work, and whether they could learn anything from it. The study is based on review of the crash reports of Flight 447, which lost flight speed indication after formation of ice prevented air from entering flight speed indicators during a storm. Following a subsequent stall, the aircraft fell at a rate of >10,000 feet/min until it crashed into the Atlantic Ocean, killing 228 passengers and crew. There were errors in decision making, reasoning, communication, and teamwork. Such non-technical skills failures have been recognized previously and can be addressed by existing non-technical skills training. A reliance on autopilot meant that the pilots were unfamiliar with high-altitude flying when the autopilot is disengaged. They were unprepared for and affected by such a sudden and serious problem; an event called "surprise and startle" by the accident investigation. The absence of the senior pilot (who was on a scheduled break) in the critical final minutes slowed error recognition and recovery. Unintended consequences of modern safety strategies may be under-recognized and can lead to adverse events. Both simulation-based and non-simulation-based training should include "surprise and startle" events beyond the scenarios trainees might expect. Likewise, in the face of increasing reliance on modern technology, surgeons should ensure that they would be able to perform procedures in the absence of such technologies. Specific training may improve surgeons' non-technical skills, and recognition of such skills could also be used to help select future surgeons.

Multi-rater Agreement in the Assessment of Anterior Cruciate Ligament Reconstruction Failure. A Radiographic and Video Analysis of the MARS Cohort

PubMed Central

Matava, Matthew J.; Arciero, Robert A.; Baumgarten, Keith M.; Carey, James L.; DeBerardino, Thomas M.; Hame, Sharon L.; Hannafin, Jo A.; Miller, Bruce S.; Nissen, Carl W.; Taft, Timothy N.; Wolf, Brian R.; Wright, Rick W.

2015-01-01

Background ACL reconstruction failure occurs in up to 10% of cases. Technical errors are considered the most common cause of graft failure despite the absence of validated studies. There is limited data regarding the agreement among orthopedic surgeons in terms of the etiology of primary ACL reconstruction failure and accuracy of graft tunnel placement. Purpose The purpose of this study is to test the hypothesis that experienced knee surgeons have a high level of inter-observer reliability in the agreement of the etiology of the primary ACL reconstruction failure, anatomical graft characteristics, tunnel placement. Methods Twenty cases of revision ACL reconstruction were randomly selected from the MARS database. Each case included the patient's history, standardized radiographs, and a concise 30-second arthroscopic video taken at the time of revision demonstrating the graft remnant and location of the tunnel apertures. 10 MARS surgeons not involved with the primary surgery reviewed all 20 cases. Each surgeon completed a two-part questionnaire dealing with each surgeon's training and practice as well as the placement of the femoral and tibial tunnels, condition of the primary graft, and the surgeon's opinion as to the etiology of graft failure. Inter-rater agreement was determined for each question. Inter-rater agreement was determined for each question with the kappa coefficient and prevalence adjusted bias adjusted kappa (PABAK). Results The 10 reviewers were in practice an average of 14 years. All performed at least 25 ACL reconstructions per year and 9 were fellowship-trained in sports medicine. There was wide variability in agreement among knee experts as to the specific etiology of ACL graft failure. When specifically asked about technical error as the cause for failure, inter-observer agreement was only slight (prevalence adjusted bias adjusted kappa [PABAK]: 0.26). There was fair overall agreement on ideal femoral tunnel placement (PABAK: 0.55), but only slight agreement whether a femoral tunnel was too anterior (PABAK: 0.24) and fair agreement whether it was too vertical (PABAK: 0.46). There was poor overall agreement for ideal tibial tunnel placement (PABAK: 0.17). Conclusion This study suggests that more objective criteria are needed to accurately determine the etiology of primary ACL graft failure as well as the ideal femoral and tibial tunnel placement in patients undergoing revision ACL reconstruction. PMID:25537942

Non-technical skills evaluation in the critical care air ambulance environment: introduction of an adapted rating instrument--an observational study.

PubMed

Myers, Julia A; Powell, David M C; Psirides, Alex; Hathaway, Karyn; Aldington, Sarah; Haney, Michael F

2016-03-08

In the isolated and dynamic health-care setting of critical care air ambulance transport, the quality of clinical care is strongly influenced by non-technical skills such as anticipating, recognising and understanding, decision making, and teamwork. However there are no published reports identifying or applying a non-technical skills framework specific to an intensive care air ambulance setting. The objective of this study was to adapt and evaluate a non-technical skills rating framework for the air ambulance clinical environment. In the first phase of the project the anaesthetists' non-technical skills (ANTS) framework was adapted to the air ambulance setting, using data collected directly from clinician groups, published literature, and field observation. In the second phase experienced and inexperienced inter-hospital transport clinicians completed a simulated critical care air transport scenario, and their non-technical skills performance was independently rated by two blinded assessors. Observed and self-rated general clinical performance ratings were also collected. Rank-based statistical tests were used to examine differences in the performance of experienced and inexperienced clinicians, and relationships between different assessment approaches and assessors. The framework developed during phase one was referred to as an aeromedical non-technical skills framework, or AeroNOTS. During phase two 16 physicians from speciality training programmes in intensive care, emergency medicine and anaesthesia took part in the clinical simulation study. Clinicians with inter-hospital transport experience performed more highly than those without experience, according to both AeroNOTS non-technical skills ratings (p = 0.001) and general performance ratings (p = 0.003). Self-ratings did not distinguish experienced from inexperienced transport clinicians (p = 0.32) and were not strongly associated with either observed general performance (r(s) = 0.4, p = 0.11) or observed non-technical skills performance (r(s) = 0.4, p = 0.1). This study describes a framework which characterises the non-technical skills required by critical care air ambulance clinicians, and distinguishes higher and lower levels of performance. The AeroNOTS framework could be used to facilitate education and training in non-technical skills for air ambulance clinicians, and further evaluation of this rating system is merited.

Risk factors for eye bank preparation failure of Descemet membrane endothelial keratoplasty tissue.

PubMed

Vianna, Lucas M M; Stoeger, Christopher G; Galloway, Joshua D; Terry, Mark; Cope, Leslie; Belfort, Rubens; Jun, Albert S

2015-05-01

To assess the results of a single eye bank preparing a high volume of Descemet membrane endothelial keratoplasty (DMEK) tissues using multiple technicians to provide an overview of the experience and to identify possible risk factors for DMEK preparation failure. Cross-sectional study. setting: Lions VisionGift and Wilmer Eye Institute at Johns Hopkins Hospital. All 563 corneal tissues processed by technicians at Lions VisionGift for DMEK between October 2011 and May 2014 inclusive. Tissues were divided into 2 groups: DMEK preparation success and DMEK preparation failure. We compared donor characteristics, including past medical history. The overall tissue preparation failure rate was 5.2%. Univariate analysis showed diabetes mellitus (P = .000028) and its duration (P = .023), hypertension (P = .021), and hyperlipidemia or obesity (P = .0004) were more common in the failure group. Multivariate analysis showed diabetes mellitus (P = .0001) and hyperlipidemia or obesity (P = .0142) were more common in the failure group. Elimination of tissues from donors either with diabetes or with hyperlipidemia or obesity reduced the failure rate from 5.2% to 2.2%. Trends toward lower failure rates occurring with increased technician experience also were found. Our work showed that tissues from donors with diabetes mellitus (especially with longer disease duration) and hyperlipidemia or obesity were associated with higher failure rates in DMEK preparation. Elimination of tissues from donors either with diabetes mellitus or with hyperlipidemia or obesity reduced the failure rate. In addition, our data may provide useful initial guidelines and benchmark values for eye banks seeking to establish and maintain DMEK programs. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of design methods to determine scour depths for bridge structures : [technical summary].

DOT National Transportation Integrated Search

2013-01-01

Scour of bridge foundations is the most common cause of bridge failures. The Federal Highway Administration : (FHWA) has developed a design method, HEC-18, for the state Departments of Transportation (DOTs) to evaluate : the scour potential of existi...

25 CFR 30.123 - What is the Bureau's role in assisting Bureau-funded schools to make AYP?

Code of Federal Regulations, 2010 CFR

2010-04-01

... EDUCATION ADEQUATE YEARLY PROGRESS Failure To Make Adequate Yearly Progress § 30.123 What is the Bureau's...-funded schools to assist them in achieving AYP. This includes technical assistance and other forms of...

25 CFR 30.123 - What is the Bureau's role in assisting Bureau-funded schools to make AYP?

Code of Federal Regulations, 2011 CFR

2011-04-01

... EDUCATION ADEQUATE YEARLY PROGRESS Failure To Make Adequate Yearly Progress § 30.123 What is the Bureau's...-funded schools to assist them in achieving AYP. This includes technical assistance and other forms of...

WILD SALMON RESTORATION IN THE PACIFIC NORTHWEST: FORECASTING THE TWENTY-FIRST CENTURY

EPA Science Inventory

Restoring wild salmon runs to the Pacific Northwest is technically challenging, politically nasty, and socially divisive. Past restoration efforst have been largely unsuccessful. Society's failure to reverse the continuing decline of wild salmon has the characteristics of a pol...

A Mixed Methods Explanatory Study of the Failure/Drop Rate for Freshman STEM Calculus Students

ERIC Educational Resources Information Center

Worthley, Mary

2013-01-01

In a national context of high failure rates in freshman calculus courses, the purpose of this study was to understand who is struggling, and why. High failure rates are especially alarming given a local environment where students have access to a variety of academic, and personal, assistance. The sample consists of students at Colorado State…

Training of residents in laparoscopic tubal sterilization: Long-term failure rates

PubMed Central

Rackow, Beth W.; Rhee, Maria C.; Taylor, Hugh S.

2011-01-01

Objectives Laparoscopic tubal sterilization with bipolar coagulation is a common and effective method of contraception, and a procedure much used to teach laparoscopic surgical skills to Obstetrics and Gynaecology residents (trainees); but it has an inherent risk of failure. This study investigated the long-term failure rate of this procedure when performed by Obstetrics and Gynaecology residents on women treated in their teaching clinics. Methods From 1991 to 1994, Obstetrics and Gynaecology residents carried out 386 laparoscopic tubal sterilizations with bipolar coagulation at Yale-New Haven Hospital. Six to nine years after the procedure, the women concerned were contacted by telephone and data were collected about sterilization failure. Results Two failures of laparoscopic tubal sterilization with bipolar coagulation were identified: an ectopic pregnancy and a spontaneous abortion. For this time period, the long-term sterilization failure rate was 1.9% (0–4.4%). Conclusions The long-term sterilization failure rate for laparoscopic tubal sterilization with bipolar coagulation performed by residents is comparable to the results of prior studies. These findings can be used to properly counsel women at a teaching clinic about the risks of sterilization failure with this procedure, and attest to the adequacy of residents’ training and supervision. PMID:18465476

An analysis of the value of spermicides in contraception.

PubMed

1979-11-01

Development of the so-called modern methods of contraception has somewhat eclipsed interest in traditional methods. However, spermicides are still important for many couples and their use appears to be increasing. A brief history of the use of and research into spermicidal contraceptives is presented. The limitations of spermicides are: the necessity for use at the time of intercourse, and their high failure rate. Estimates of the failure rates of spermicides have ranged from .3 pregnancies per 100 woman-years of use to nearly 40, depending on the product used and the population tested. Just as their use depends on various social factors, so does their failure rate. Characteristics of the user deterine failure rates. Motivation is important in lowering failure rates as is education, the intracouple relationship, and previous experience with spermicides. Method failure is also caused by defects in the product, either in the active ingredient of the spermicide or in the base carrier. The main advantage of spermicidal contraception is its safety. Limited research is currently being conducted on spermicides. Areas for improvement in existing spermicides and areas for possible innovation are mentioned.

The management of neonatal acute and chronic renal failure: A review.

PubMed

Coulthard, Malcolm G

2016-11-01

Most babies with chronic renal failure are identified antenatally, and over half that are treated with peritoneal dialysis receive kidney transplants before school age. Most infants that develop acute renal failure have hypotension following cardiac surgery, or multiple organ failure. Sometimes the falls in glomerular filtration and urine output are physiological and reversible, and sometimes due to kidney injury, but (illogically) it is now common to define them all as having 'acute kidney injury'. Contrary to widespread opinion, careful interpretation of the plasma creatinine concentrations can provide sensitive evidence of early acute renal failure. Conservative management frequently leads to under-nutrition or fluid overload. Acute peritoneal dialysis is often technically fraught in very small patients, and haemotherapies have been limited by vascular access and anticoagulation requirements, the need to blood-prime circuits, and serious limitations in regulating fluid removal. Newer devices, including the Nidus, have been specifically designed to reduce these difficulties. Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.

On possibilities of using global monitoring in effective prevention of tailings storage facilities failures.

PubMed

Stefaniak, Katarzyna; Wróżyńska, Magdalena

2018-02-01

Protection of common natural goods is one of the greatest challenges man faces every day. Extracting and processing natural resources such as mineral deposits contributes to the transformation of the natural environment. The number of activities designed to keep balance are undertaken in accordance with the concept of integrated order. One of them is the use of comprehensive systems of tailings storage facility monitoring. Despite the monitoring, system failures still occur. The quantitative aspect of the failures illustrates both the scale of the problem and the quantitative aspect of the consequences of tailings storage facility failures. The paper presents vast possibilities provided by the global monitoring in the effective prevention of these failures. Particular attention is drawn to the potential of using multidirectional monitoring, including technical and environmental monitoring by the example of one of the world's biggest hydrotechnical constructions-Żelazny Most Tailings Storage Facility (TSF), Poland. Analysis of monitoring data allows to take preventive action against construction failures of facility dams, which can have devastating effects on human life and the natural environment.

Management of failure after surgery for gastro-esophageal reflux disease.

PubMed

Gronnier, C; Degrandi, O; Collet, D

2018-04-01

Surgical treatment of gastro-esophageal reflux disease (ST-GERD) is well-codified and offers an alternative to long-term medical treatment with a better efficacy for short and long-term outcomes. However, failure of ST-GERD is observed in 2-20% of patients; management is challenging and not standardized. The aim of this study is to analyze the causes of failure and to provide a treatment algorithm. The clinical aspects of ST-GERD failure are variable including persistent reflux, dysphagia or permanent discomfort leading to an important degradation of the quality of life. A morphological and functional pre-therapeutic evaluation is necessary to: (i) determine whether the symptoms are due to recurrence of reflux or to an error in initial indication and (ii) to understand the cause of the failure. The most frequent causes of failure of ST-GERD include errors in the initial indication, which often only need medical treatment, and surgical technical errors, for which surgical redo surgery can be difficult. Multidisciplinary management is necessary in order to offer the best-adapted treatment. Copyright © 2018. Published by Elsevier Masson SAS.

Comparative study of two modes of gastroesophageal reflux measuring: conventional esophageal pH monitoring and wireless pH monitoring.

PubMed

Azzam, Rimon Sobhi; Sallum, Rubens A A; Brandão, Jeovana Ferreira; Navarro-Rodriguez, Tomás; Nasi, Ary

2012-01-01

Esophageal pH monitoring is considered to be the gold standard for the diagnosis of gastroesophageal acid reflux. However, this method is very troublesome and considerably limits the patient's routine activities. Wireless pH monitoring was developed to avoid these restrictions. To compare the first 24 hours of the conventional and wireless pH monitoring, positioned 3 cm above the lower esophageal sphincter, in relation to: the occurrence of relevant technical failures, the ability to detect reflux and the ability to correlate the clinical symptoms to reflux. Twenty-five patients referred for esophageal pH monitoring and with typical symptoms of gastroesophageal reflux disease were studied prospectively, underwent clinical interview, endoscopy, esophageal manometry and were submitted, with a simultaneous initial period, to 24-hour catheter pH monitoring and 48-hour wireless pH monitoring. Early capsule detachment occurred in one (4%) case and there were no technical failures with the catheter pH monitoring (P = 0.463). Percentages of reflux time (total, upright and supine) were higher with the wireless pH monitoring (P < 0.05). Pathological gastroesophageal reflux occurred in 16 (64%) patients submitted to catheter and in 19 (76%) to the capsule (P = 0.355). The symptom index was positive in 12 (48%) patients with catheter pH monitoring and in 13 (52%) with wireless pH monitoring (P = 0.777). 1) No significant differences were reported between the two methods of pH monitoring (capsule vs catheter), in regard to relevant technical failures; 2) Wireless pH monitoring detected higher percentages of reflux time than the conventional pH-metry; 3) The two methods of pH monitoring were comparable in diagnosis of pathological gastroesophageal reflux and comparable in correlating the clinical symptoms with the gastroesophageal reflux.

Technical-Induced Hemolysis in Patients with Respiratory Failure Supported with Veno-Venous ECMO - Prevalence and Risk Factors.

PubMed

Lehle, Karla; Philipp, Alois; Zeman, Florian; Lunz, Dirk; Lubnow, Matthias; Wendel, Hans-Peter; Göbölös, Laszlo; Schmid, Christof; Müller, Thomas

2015-01-01

The aim of the study was to explore the prevalence and risk factors for technical-induced hemolysis in adults supported with veno-venous extracorporeal membrane oxygenation (vvECMO) and to analyze the effect of hemolytic episodes on outcome. This was a retrospective, single-center study that included 318 adult patients (Regensburg ECMO Registry, 2009-2014) with acute respiratory failure treated with different modern miniaturized ECMO systems. Free plasma hemoglobin (fHb) was used as indicator for hemolysis. Throughout a cumulative support duration of 4,142 days on ECMO only 1.7% of the fHb levels were above a critical value of 500 mg/l. A grave rise in fHb indicated pumphead thrombosis (n = 8), while acute oxygenator thrombosis (n = 15) did not affect fHb. Replacement of the pumphead normalized fHb within two days. Neither pump or cannula type nor duration on the first system was associated with hemolysis. Multiple trauma, need for kidney replacement therapy, increased daily red blood cell transfusion requirements, and high blood flow (3.0-4.5 L/min) through small-sized cannulas significantly resulted in augmented blood cell trauma. Survivors were characterized by lower peak levels of fHb [90 (60, 142) mg/l] in comparison to non-survivors [148 (91, 256) mg/l, p≤0.001]. In conclusion, marked hemolysis is not common in vvECMO with modern devices. Clinically obvious hemolysis often is caused by pumphead thrombosis. High flow velocity through small cannulas may also cause technical-induced hemolysis. In patients who developed lung failure due to trauma, fHb was elevated independantly of ECMO. In our cohort, the occurance of hemolysis was associated with increased mortality.

Technical-Induced Hemolysis in Patients with Respiratory Failure Supported with Veno-Venous ECMO – Prevalence and Risk Factors

PubMed Central

Lehle, Karla; Philipp, Alois; Zeman, Florian; Lunz, Dirk; Lubnow, Matthias; Wendel, Hans-Peter; Göbölös, Laszlo; Schmid, Christof; Müller, Thomas

2015-01-01

The aim of the study was to explore the prevalence and risk factors for technical-induced hemolysis in adults supported with veno-venous extracorporeal membrane oxygenation (vvECMO) and to analyze the effect of hemolytic episodes on outcome. This was a retrospective, single-center study that included 318 adult patients (Regensburg ECMO Registry, 2009–2014) with acute respiratory failure treated with different modern miniaturized ECMO systems. Free plasma hemoglobin (fHb) was used as indicator for hemolysis. Throughout a cumulative support duration of 4,142 days on ECMO only 1.7% of the fHb levels were above a critical value of 500 mg/l. A grave rise in fHb indicated pumphead thrombosis (n = 8), while acute oxygenator thrombosis (n = 15) did not affect fHb. Replacement of the pumphead normalized fHb within two days. Neither pump or cannula type nor duration on the first system was associated with hemolysis. Multiple trauma, need for kidney replacement therapy, increased daily red blood cell transfusion requirements, and high blood flow (3.0–4.5 L/min) through small-sized cannulas significantly resulted in augmented blood cell trauma. Survivors were characterized by lower peak levels of fHb [90 (60, 142) mg/l] in comparison to non-survivors [148 (91, 256) mg/l, p≤0.001]. In conclusion, marked hemolysis is not common in vvECMO with modern devices. Clinically obvious hemolysis often is caused by pumphead thrombosis. High flow velocity through small cannulas may also cause technical-induced hemolysis. In patients who developed lung failure due to trauma, fHb was elevated independantly of ECMO. In our cohort, the occurance of hemolysis was associated with increased mortality. PMID:26606144

Influence of enamel preservation on failure rates of porcelain laminate veneers.

PubMed

Gurel, Galip; Sesma, Newton; Calamita, Marcelo A; Coachman, Christian; Morimoto, Susana

2013-01-01

The purpose of this study was to evaluate the failure rates of porcelain laminate veneers (PLVs) and the influence of clinical parameters on these rates in a retrospective survey of up to 12 years. Five hundred eighty laminate veneers were bonded in 66 patients. The following parameters were analyzed: type of preparation (depth and margin), crown lengthening, presence of restoration, diastema, crowding, discoloration, abrasion, and attrition. Survival was analyzed using the Kaplan-Meier method. Cox regression modeling was used to determine which factors would predict PLV failure. Forty-two veneers (7.2%) failed in 23 patients, and an overall cumulative survival rate of 86% was observed. A statistically significant association was noted between failure and the limits of the prepared tooth surface (margin and depth). The most frequent failure type was fracture (n = 20). The results revealed no significant influence of crown lengthening apically, presence of restoration, diastema, discoloration, abrasion, or attrition on failure rates. Multivariable analysis (Cox regression model) also showed that PLVs bonded to dentin and teeth with preparation margins in dentin were approximately 10 times more likely to fail than PLVs bonded to enamel. Moreover, coronal crown lengthening increased the risk of PLV failure by 2.3 times. A survival rate of 99% was observed for veneers with preparations confined to enamel and 94% for veneers with enamel only at the margins. Laminate veneers have high survival rates when bonded to enamel and provide a safe and predictable treatment option that preserves tooth structure.

Technical efficiency of nursing homes: do five-star quality ratings matter?

PubMed

Dulal, Rajendra

2017-02-28

This study investigates associations between five-star quality ratings and technical efficiency of nursing homes. The sample consists of a balanced panel of 338 nursing homes in California from 2009 through 2013 and uses two-stage data envelopment (DEA) analysis. The first-stage applies an input oriented variable returns to scale DEA analysis. The second-stage uses a left censored random-effect Tobit regression model. The five-star quality ratings i.e., health inspections, quality measures, staffing available on the Nursing Home Compare website are divided into two categories: outcome and structure form of quality. Results show that quality measures ratings and health inspection ratings, used as outcome form of quality, are not associated with mean technical efficiency. These quality ratings, however, do affect the technical efficiency of a particular nursing home and hence alter the ranking of nursing homes based on efficiency scores. Staffing rating, categorized as a structural form of quality, is negatively associated with mean technical efficiency. These findings show that quality dimensions are associated with technical efficiency in different ways, suggesting that multiple dimensions of quality should be included in the efficiency analysis of nursing homes. They also suggest that patient care can be enhanced through investing more in improving care delivery rather than simply raising the number of staff per resident.

Complications of short versus long cephalomedullary nail for intertrochanteric femur fractures, minimum 1 year follow-up.

PubMed

Vaughn, Josh; Cohen, Eric; Vopat, Bryan G; Kane, Patrick; Abbood, Emily; Born, Christopher

2015-05-01

Hip fractures are becoming increasingly common resulting in significant morbidity, mortality and raising healthcare costs. Both short and long cephalomedullary devices are currently employed to treat intertrochanteric hip fractures. However, which device is optimal continues to be debated as each implant has unique characteristics and theoretical advantages. This study looked to identify rates of complications associated with both long and short cephalomedullary nails for the treatment of intertrochanteric hip fractures. We retrospectively reviewed charts from 2006 to 2011, and we identified 256 patients were identified with AO class 31.1-32.3 fractures. Sixty were treated with short nails and 196 with long nails. Radiographs and charts were then analysed for failures and hardware complications. Catastrophic failure and hardware complication rates were not statistically different between short or long cephalomedullary nails. The overall catastrophic failure rate was 3.1 %; there was a 5 % failure rate in the short-nail group compared with a 2.6 % failure rate in the long-nail group (p = 0.191). There was a 3.33 % secondary femur fracture rate in the short-nail group, compared with none in the long-nail cohort (p = 0.054). The rate of proximal fixation failure was 1.67 % for the short-nail group and 2.0 % in the long-nail group (p = 0.406). Our data suggests equivocal outcomes as measured by similar catastrophic failure rate between both short and long cephalomedullary nails for intertrochanteric femur fractures. However, there was an increased risk of secondary femur fracture with short cephalomedullary nails when compared to long nails that approached statistical significance.

Evaluation of Google Glass Technical Limitations on Their Integration in Medical Systems.

PubMed

Martinez-Millana, Antonio; Bayo-Monton, Jose-Luis; Lizondo, Aroa; Fernandez-Llatas, Carlos; Traver, Vicente

2016-12-15

Google Glass is a wearable sensor presented to facilitate access to information and assist while performing complex tasks. Despite the withdrawal of Google in supporting the product, today there are multiple applications and much research analyzing the potential impact of this technology in different fields of medicine. Google Glass satisfies the need of managing and having rapid access to real-time information in different health care scenarios. Among the most common applications are access to electronic medical records, display monitorizations, decision support and remote consultation in specialties ranging from ophthalmology to surgery and teaching. The device enables a user-friendly hands-free interaction with remote health information systems and broadcasting medical interventions and consultations from a first-person point of view. However, scientific evidence highlights important technical limitations in its use and integration, such as failure in connectivity, poor reception of images and automatic restart of the device. This article presents a technical study on the aforementioned limitations (specifically on the latency, reliability and performance) on two standard communication schemes in order to categorize and identify the sources of the problems. Results have allowed us to obtain a basis to define requirements for medical applications to prevent network, computational and processing failures associated with the use of Google Glass.

Evaluation of Google Glass Technical Limitations on Their Integration in Medical Systems

PubMed Central

Martinez-Millana, Antonio; Bayo-Monton, Jose-Luis; Lizondo, Aroa; Fernandez-Llatas, Carlos; Traver, Vicente

2016-01-01

Google Glass is a wearable sensor presented to facilitate access to information and assist while performing complex tasks. Despite the withdrawal of Google in supporting the product, today there are multiple applications and much research analyzing the potential impact of this technology in different fields of medicine. Google Glass satisfies the need of managing and having rapid access to real-time information in different health care scenarios. Among the most common applications are access to electronic medical records, display monitorizations, decision support and remote consultation in specialties ranging from ophthalmology to surgery and teaching. The device enables a user-friendly hands-free interaction with remote health information systems and broadcasting medical interventions and consultations from a first-person point of view. However, scientific evidence highlights important technical limitations in its use and integration, such as failure in connectivity, poor reception of images and automatic restart of the device. This article presents a technical study on the aforementioned limitations (specifically on the latency, reliability and performance) on two standard communication schemes in order to categorize and identify the sources of the problems. Results have allowed us to obtain a basis to define requirements for medical applications to prevent network, computational and processing failures associated with the use of Google Glass. PMID:27983691

Seismic microzonation in Latin America and the Caribbean: social, cultural, economic and political aspects

NASA Astrophysics Data System (ADS)

Murria, J.

2009-04-01

The lack of success, not to say failure, of seismic microzonation projects in the Latin America and Caribbean nations-and for that matter elsewhere in the world-should not be attributed to the lack of technical and scientific expertise of our engineers and scientists as there exists in our continent sufficient knowledge and information about the techniques and procedures that have been successfully used elsewhere in the world in the implementation of seismic microzonation projects. The main constrains to the implementation of seismic microzonation projects in Latin America and the Caribbean are of an economic, social, political, and cultural aspects rather than the purely scientific and engineering aspects. Another very important factor contributing to this lack of success has been the apparent failure of the scientific and technical community to convince decision makers (both official and private) that the sound implementation of seismic microzonation projects are a valid instrument to mitigate the negative effects that earthquakes have on the population, on the physical infrastructure and on the environment. An attempt will be made in this paper to analyze these "non technical" aspects and try to arrive at some conclusions as well as to some possible lines of action for the successful implementation of seismic microzonation projects in the seismic risk prone Latin American and Caribbean nations.

T-F and S/DOE Gladys McCall No. 1 well, Cameron Parish, Louisiana. Geopressured-geothermal well report, Volume II. Well workover and production testing, February 1982-October 1985. Final report. Appendices 1-7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1985-01-01

These appendices contain the following reports: (1) investigation of coupling failure from the Gladys McCall No. 1 well; (2) failure analysis - oil well casing coupling; (3) technical remedial requirements for 5-inch production tubing string; (4) reservoir limit test data for sand zone No. 9; (5) reservoir fluid study - sand zone No. 9; (6) engineering interpretation of exploration drawdown tests; and (7) reservoir analysis. (ACR)

A new criterion needed to evaluate reliability of digital protective relays

NASA Astrophysics Data System (ADS)

Gurevich, Vladimir

2012-11-01

There is a wide range of criteria and features for evaluating reliability in engineering; but as many as there are, only one of them has been chosen to evaluate reliability of Digital Protective Relays (DPR) in the technical documentation: Mean (operating) Time Between Failures (MTBF), which has gained universal currency and has been specified in technical manuals, information sheets, tender documentation as the key indicator of DPR reliability. But is the choice of this criterion indeed wise? The answer to this question is being sought by the author of this article.

NASA's Lessons Learned and Technical Standards: A Logical Marriage

NASA Technical Reports Server (NTRS)

Gill, Paul; Vaughan, William W.; Garcia, Danny; Weinstein, Richard

2001-01-01

Lessons Learned have been the basis for our accomplishments throughout the ages. They have been passed down from father to son, mother to daughter, teacher to pupil, and older to younger worker. Lessons Learned have also been the basis for NASA's accomplishments for more than forty years. Both government and industry have long recognized the need to systematically document and utilize the knowledge gained from past experiences in order to avoid the repetition of failures and mishaps. Lessons Learned have formed the foundation for discoveries, inventions, improvements, textbooks, and Technical Standards.

[Platforms are needed for innovative basic research in ophthalmology].

PubMed

Wang, Yi-qiang

2012-07-01

Basic research poses the cornerstone of technical innovation in all lines including medical sciences. Currently, there are shortages of professional scientists as well as technical supporting teams and facilities in the field of basic research of ophthalmology and visual science in China. Evaluation system and personnel policies are not supportive for innovative but high-risk-of-failure research projects. Discussion of reasons and possible solutions are given here to address these problems, aiming at promoting buildup of platforms hosting novel and important basic research in eye science in this country.

Artificial Immune System for Flight Envelope Estimation and Protection

DTIC Science & Technology

2014-12-31

Throttle Failure 103 5.3. Estimation Algorithms for Sensor AC 108 5.3.1. Roll Rate Sensor Bias 108...4.13. Reference Features-Pattern for a Roll Rate Sensor Under Low Severity Failure 93 Figure 4.14. Reference Features-Pattern for a Roll Rate...Average PI for Different ACs 134 Figure 6.9. Roll Response Under High Magnitude Stabilator Failure 135 Figure 6.10. Pitch

Improving non-technical skills (teamwork) in post-partum haemorrhage: A grouped randomised trial.

PubMed

Letchworth, Pippa M; Duffy, Shane P; Phillips, Dan

2017-10-01

To determine the effect of a decision support technology on teamwork and associated non-technical (NTS) and technical skills when teams manage post-partum haemorrhage (PPH) in the simulated environment. Multidisciplinary (MDT) maternity teams were taught how to manage post partum haemorrhage. They were randomised to the intervention: using a decision support mobile digital platform or a control group. Each team managed a post-partum simulation, which was recorded and reviewed by assessors. Primary outcome measures to assess teams NTS were the validated Global Assessment of Obstetric Team Performance (GAOTP) and Clinical Teamwork Scale (CTS). Secondary outcome measures were the 'friends and family test', technical skills, and the System Usability Scale (SUS). Sample size estimation was calculated by using 80% power 5% significance two tailed test (p1=85% p2=40%) n=34. 38 teams from August 2014-February 2016, were recruited, technical issues with failure of recording equipment meant 4 teams were excluded from teamwork analysis (1 intervention 3 control). Teamwork improved across all domains with the intervention (using a decision support mobile digital platform) p <0.01. CTS improved between 6.7-16.8% (average 14.2%) and GAOTP between 8.6-17.1% (average 13.5%) for all domains. Using the control group as baseline, the intervention improved teamwork by 25% using CTS and 22% using GAOTP. Fewer technical skills were missed with the intervention (p<0.01). There was no statistical difference in the time technical skills were achieved. Assessors were more likely to recommend intervention teams 87.5% (77/88) than control teams 63.6% (56/88) p<0.01 to their friends or family. The SUS was 'Good' (69) becoming excellently 'Usable' (81.6) over the study period. We report a decision support system, which improved NTS when managing PPH. Lack of teamwork is often cited as the cause of failures in care and we report a usable technology that assists with and improves teamwork during an emergency. Copyright © 2017 Elsevier B.V. All rights reserved.

78 FR 15 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-02

... AD requires repetitive overhaul of the NLG retraction actuator. We are issuing this AD to prevent failure of the retraction actuator, which could cause collapse of the NLG after touchdown and possible... subsequent technical investigations revealed that the NLG retraction actuator eye-end fitting was detached...

Potential for Fuel Tank Fire and Hydrodynamic Ram from Uncontained Aircraft Engine Debris

DOT National Transportation Integrated Search

1997-01-01

This report addresses the potential consequences of the impact and penetration of fuel tanks by debris from uncontained engine failures on commercial jet aircraft. The report presents a brief review of accident data and of the pertinent technical lit...

Report Card on Nuclear Power

ERIC Educational Resources Information Center

Novick, Sheldon

1974-01-01

Problems facing the nuclear power industry include skyrocketing construction costs, technical failures, fuel scarcity, power plant safety, and the disposal of nuclear wastes. Possible solutions include: reductions in nuclear power plant construction, a complete moratorium on new plant construction, the construction of fast breeder reactors and the…

Addressing Control Research Issues Leading to Piloted Simulations in Support of the IFCS F-15

NASA Technical Reports Server (NTRS)

Napolitano, Marcello; Perhinschi, Mario; Campa, Giampiero; Seanor, Brad

2004-01-01

This report summarizes the research effort by a team of researchers at West Virginia University in support of the NASA Intelligent Flight Control System (IFCS) F-15 program. In particular, WVU researchers assisted NASA Dryden researchers in the following technical tasks leading to piloted simulation of the 'Gen_2' IFCS control laws. Task #1- Performance comparison of different neural network (NN) augmentation for the Dynamic Inversion (DI) -based VCAS 'Gen_2' control laws. Task #2- Development of safety monitor criteria for transition to research control laws with and without failure during flight test. Task #3- Fine-tuning of the 'Gen_2' control laws for cross-coupling reduction at post-failure conditions. Matlab/Simulink-based simulation codes were provided to the technical monitor on a regular basis throughout the duration of the project. Additional deliverables for the project were Power Point-based slides prepared for different project meetings. This document provides a description of the methodology and discusses the general conclusions from the simulation results.

Constructing failure in big biology: The socio-technical anatomy of Japan's Protein 3000 Project.

PubMed

Fukushima, Masato

2016-02-01

This study focuses on the 5-year Protein 3000 Project launched in 2002, the largest biological project in Japan. The project aimed to overcome Japan's alleged failure to contribute fully to the Human Genome Project, by determining 3000 protein structures, 30 percent of the global target. Despite its achievement of this goal, the project was fiercely criticized in various sectors of society and was often branded an awkward failure. This article tries to solve the mystery of why such failure discourse was prevalent. Three explanatory factors are offered: first, because some goals were excluded during project development, there was a dynamic of failed expectations; second, structural genomics, while promoting collaboration with the international community, became an 'anti-boundary object', only the absence of which bound heterogeneous domestic actors; third, there developed an urgent sense of international competition in order to obtain patents on such structural information.

[Value of ultrasonically-guided liver puncture biopsy in the diagnosis of primary liver cancer. Apropos of 84 cases].

PubMed

Peghini, M; Eynard, J P; Vergne, R; Seurat, P; Barabe, P; Aubry, P; Diallo, A; Gueye, P M

1987-01-01

Ultrasonographicaly guided fine needle aspiration of liver was performed in 84 patients having a confirmed HCC. This technics utilizes a CHIBA type fine needle, after blood coagulation tests have been checked. Out of 84 fine needle aspirations performed: 64 were positive (76,2%), 9 negative (10,7%), 11 (13,19%) were questionable (6) or nonanalysable (5). It is ascertained that the sensibility of this technics is over 75%. It should be possible to improve it by repeating such an exam in previously negative patients. The causes of failure are discussed. Tolerance of the technics is good. It is attraumatic, and of very easily performance. No accident, no mishap was noted.

Strategy for the management of uncomplicated retinal detachments: the European vitreo-retinal society retinal detachment study report 1.

PubMed

Adelman, Ron A; Parnes, Aaron J; Ducournau, Didier

2013-09-01

To study success and failure in the treatment of uncomplicated rhegmatogenous retinal detachments (RRDs). Nonrandomized, multicenter retrospective study. One hundred seventy-six surgeons from 48 countries spanning 5 continents provided information on the primary procedures for 7678 cases of RRDs including 4179 patients with uncomplicated RRDs. Reported data included specific clinical findings, the method of repair, and the outcome after intervention. Final failure of retinal detachment repair (level 1 failure rate), remaining silicone oil at the study's conclusion (level 2 failure rate), and need for additional procedures to repair the detachment (level 3 failure rate). Four thousand one hundred seventy-nine uncomplicated cases of RRD were included. Combining phakic, pseudophakic, and aphakic groups, those treated with scleral buckle alone (n = 1341) had a significantly lower final failure rate than those treated with vitrectomy, with or without a supplemental buckle (n = 2723; P = 0.04). In phakic patients, final failure rate was lower in the scleral buckle group compared with those who had vitrectomy, with or without a supplemental buckle (P = 0.028). In pseudophakic patients, the failure rate of the initial procedure was lower in the vitrectomy group compared with the scleral buckle group (P = 3×10(-8)). There was no statistically significant difference in failure rate between segmental (n = 721) and encircling (n = 351) buckles (P = 0.5). Those who underwent vitrectomy with a supplemental scleral buckle (n = 488) had an increased failure rate compared with those who underwent vitrectomy alone (n = 2235; P = 0.048). Pneumatic retinopexy was found to be comparable with scleral buckle when a retinal hole was present (P = 0.65), but not in cases with a flap tear (P = 0.034). In the treatment of uncomplicated phakic retinal detachments, repair using scleral buckle may be a good option. There was no significant difference between segmental versus 360-degree buckle. For pseudophakic uncomplicated retinal detachments, the surgeon should balance the risks and benefits of vitrectomy versus scleral buckle and keep in mind that the single-surgery reattachment rate may be higher with vitrectomy. However, if a vitrectomy is to be performed, these data suggest that a supplemental buckle is not helpful. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Retrospective study of rapid-exchange monorail versus over-the-wire technique for femoropopliteal angioplasty.

PubMed

Jahnke, Thomas; Schäfer, Jost Philipp; Bolte, Hendrik; Schäfer, Fritz; Michalek, Jens; Charalambous, Nicholas; Sapoval, Marc; Müller-Hülsbeck, Stefan

2008-01-01

The purpose of this study was to compare procedural outcome of rapid-exchange (RX) monorail versus conventional over-the-wire (OTW) technique for femoropopliteal angioplasty. Demographic data, procedure details, angioplasty success, and complications of 328 consecutive percutaneous transluminal angioplasties (PTAs) were collected from a prospective database and retrospectively analyzed. Procedure details included duration of fluoroscopy, area-dose product, amount of contrast agent, sheath sizes, access route, length of stenosis, presence of total occlusion, technical and anatomical success (residual stenosis < 30% in the absence of complications), need for bail-out stenting, and periprocedural complications. The RX technique alone was used in 102 of 328 cases (31%); the OTW technique, in 226 of 328 of cases (68%). Technical success was 98% for the RX versus 95.4% for the OTW technique (p = 0.2). A significantly greater number of stents had to be implanted due to angioplasty failure when the OTW technique was used (RX, 5.9%; OTW, 13.7%; p = 0.04). There were no significant differences in fluoroscopy time, dose-area product, or amount of contrast medium used. The RX system facilitated the use of smaller sheath sizes (5 Fr = 38% and 6 Fr = 59% for RX versus 5 Fr = 16.8% and > or = 6 Fr = 82.5% for OTW) but showed only a tendency toward lower overall complication rates (16.6% [17/102] in the RX group versus 19.9% [45/226] in the OTW group; p = 0.09). There was no effect on length of hospitalization. RX monorail systems were not associated with higher procedural costs when compared to conventional OTW technique. We conclude that RX monorail systems seem to enhance the technical success of femoropopliteal angioplasty. Although smaller sheath sizes can be used due to the lower profile of the RX systems, there is only a tendency toward lower complication rates.

Validity testing and neuropsychology practice in the VA healthcare system: results from recent practitioner survey (.).

PubMed

Young, J Christopher; Roper, Brad L; Arentsen, Timothy J

2016-05-01

A survey of neuropsychologists in the Veterans Health Administration examined symptom/performance validity test (SPVT) practices and estimated base rates for patient response bias. Invitations were emailed to 387 psychologists employed within the Veterans Affairs (VA), identified as likely practicing neuropsychologists, resulting in 172 respondents (44.4% response rate). Practice areas varied, with 72% at least partially practicing in general neuropsychology clinics and 43% conducting VA disability exams. Mean estimated failure rates were 23.0% for clinical outpatient, 12.9% for inpatient, and 39.4% for disability exams. Failure rates were the highest for mTBI and PTSD referrals. Failure rates were positively correlated with the number of cases seen and frequency and number of SPVT use. Respondents disagreed regarding whether one (45%) or two (47%) failures are required to establish patient response bias, with those administering more measures employing the more stringent criterion. Frequency of the use of specific SPVTs is reported. Base rate estimates for SPVT failure in VA disability exams are comparable to those in other medicolegal settings. However, failure in routine clinical exams is much higher in the VA than in other settings, possibly reflecting the hybrid nature of the VA's role in both healthcare and disability determination. Generally speaking, VA neuropsychologists use SPVTs frequently and eschew pejorative terms to describe their failure. Practitioners who require only one SPVT failure to establish response bias may overclassify patients. Those who use few or no SPVTs may fail to identify response bias. Additional clinical and theoretical implications are discussed.

Scoping review: Hospital nursing factors associated with 30-day readmission rates of patients with heart failure.

PubMed

Jun, Jin; Faulkner, Kenneth M

2018-04-01

To review the current literature on hospital nursing factors associated with 30-day readmission rates of patients with heart failure. Heart failure is a common, yet debilitating chronic illness with high mortality and morbidity. One in five patients with heart failure will experience unplanned readmission to a hospital within 30 days. Given the significance of heart failure to individuals, families and healthcare system, the Center for Medicare and Medicaid Services has made reducing 30-day readmission rates a priority. Scoping review, which maps the key concepts of a research area, is used. Published primary studies in English assessing factors related to nurses in hospitals and readmission of patients with heart failure were included. Other inclusion criteria were written in English and published in peer-reviewed journals. The search resulted in 2,782 articles. After removing duplicates and reviewing the inclusion and exclusion criteria, five articles were selected. Three nursing workforce factors emerged as follows: (i) nursing staffing, (ii) nursing care and work environment, and (iii) nurses' knowledge of heart failure. This is the first scoping review examining the association between hospital nursing factors and 30-day readmission rates of patients with heart failure. Further studies examining the extent of nursing structural and process factors influencing the outcomes of patients with heart failure are needed. Nurses are an integral part of the healthcare system. Identifying the factors related to nurses in hospitals is important to ensure comprehensive delivery of care to the chronically ill population. Hospital administrators, managers and policymakers can use the findings from this review to implement strategies to reduce 30-day readmission rates of patients with heart failure. © 2018 John Wiley & Sons Ltd.

Comparative study of the failure rates among 3 implantable defibrillator leads.

PubMed

van Malderen, Sophie C H; Szili-Torok, Tamas; Yap, Sing C; Hoeks, Sanne E; Zijlstra, Felix; Theuns, Dominic A M J

2016-12-01

After the introduction of the Biotronik Linox S/SD high-voltage lead, several cases of early failure have been observed. The purpose of this article was to assess the performance of the Linox S/SD lead in comparison to 2 other contemporary leads. We used the prospective Erasmus MC ICD registry to identify all implanted Linox S/SD (n = 408), Durata (St. Jude Medical, model 7122) (n = 340), and Endotak Reliance (Boston Scientific, models 0155, 0138, and 0158) (n = 343) leads. Lead failure was defined by low- or high-voltage impedance, failure to capture, sense or defibrillate, or the presence of nonphysiological signals not due to external interference. During a median follow-up of 5.1 years, 24 Linox (5.9%), 5 Endotak (1.5%), and 5 Durata (1.5%) leads failed. At 5-year follow-up, the cumulative failure rate of Linox leads (6.4%) was higher than that of Endotak (0.4%; P < .0001) and Durata (2.0%; P = .003) leads. The incidence rate was higher in Linox leads (1.3 per 100 patient-years) than in Endotak and Durata leads (0.2 and 0.3 per 100 patient-years, respectively; P < .001). A log-log analysis of the cumulative hazard for Linox leads functioning at 3-year follow-up revealed a stable failure rate of 3% per year. The majority of failures consisted of noise (62.5%) and abnormal impedance (33.3%). This study demonstrates a higher failure rate of Linox S/SD high-voltage leads compared to contemporary leads. Although the mechanism of lead failure is unclear, the majority presents with abnormal electrical parameters. Comprehensive monitoring of Linox S/SD high-voltage leads includes remote monitoring to facilitate early detection of lead failure. Copyright © 2016. Published by Elsevier Inc.

Failure factors in non-life insurance companies in United Kingdom

NASA Astrophysics Data System (ADS)

Samsudin, Humaida Banu

2013-04-01

Failure in insurance company is a condition of financial distress where a company has difficulty paying off its financial obligations to its creditors. This study continues the research from the study in identifying the determinants for run-off non-life insurance companies in United Kingdom. The analysis continues to identify other variables that could lead companies to financial distress that is macroeconomic factors (GDP rates, inflation rates and interest rates); total companies failed a year before and average size for failed companies'. The result from the analysis indicates that inflation rates, interest rates, total companies failed a year before and average sizes for failed companies are the best predictors. An early detection of failure can prevent companies from bankruptcy and allow management to take action to reduce the failure costs.

Failure Rates and Patterns of Recurrence in Patients With Resected N1 Non-Small-Cell Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varlotto, John M., E-mail: jvarlotto@hmc.psu.edu; Medford-Davis, Laura Nyshel; Recht, Abram

2011-10-01

Purpose: To examine the local and distant recurrence rates and patterns of failure in patients undergoing potentially curative resection of N1 non-small-cell lung cancer. Methods and Materials: The study included 60 consecutive unirradiated patients treated from 2000 to 2006. Median follow-up was 30 months. Failure rates were calculated by the Kaplan-Meier method. A univariate Cox proportional hazard model was used to assess factors associated with recurrence. Results: Local and distant failure rates (as the first site of failure) at 2, 3, and 5 years were 33%, 33%, and 46%; and 26%, 26%, and 32%, respectively. The most common site ofmore » local failure was in the mediastinum; 12 of 18 local recurrences would have been included within proposed postoperative radiotherapy fields. Patients who received chemotherapy were found to be at increased risk of local failure, whereas those who underwent pneumonectomy or who had more positive nodes had significantly increased risks of distant failure. Conclusions: Patients with resected non-small-cell lung cancer who have N1 disease are at substantial risk of local recurrence as the first site of relapse, which is greater than the risk of distant failure. The role of postoperative radiotherapy in such patients should be revisited in the era of adjuvant chemotherapy.« less

A Decreasing Failure Rate, Mixed Exponential Model Applied to Reliability.

DTIC Science & Technology

1981-06-01

Trident missile systems have been observed. The mixed exponential distribu- tion has been shown to fit the life data for the electronic equipment on...these systems . This paper discusses some of the estimation problems which occur with the decreasing failure rate mixed exponential distribution when...assumption of constant or increasing failure rate seemed to be incorrect. 2. However, the design of this electronic equipment indicated that

High-Strain Rate Failure Modeling Incorporating Shear Banding and Fracture

DTIC Science & Technology

2017-11-22

High Strain Rate Failure Modeling Incorporating Shear Banding and Fracture The views, opinions and/or findings contained in this report are those of...SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6. AUTHORS...Report as of 05-Dec-2017 Agreement Number: W911NF-13-1-0238 Organization: Columbia University Title: High Strain Rate Failure Modeling Incorporating

Mechanistic Considerations Used in the Development of the PROFIT PCI Failure Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pankaskie, P. J.

A fuel Pellet-Zircaloy Cladding (thermo-mechanical-chemical) Interactions (PC!) failure model for estimating the probability of failure in !ransient increases in power (PROFIT) was developed. PROFIT is based on 1) standard statistical methods applied to available PC! fuel failure data and 2) a mechanistic analysis of the environmental and strain-rate-dependent stress versus strain characteristics of Zircaloy cladding. The statistical analysis of fuel failures attributable to PCI suggested that parameters in addition to power, transient increase in power, and burnup are needed to define PCI fuel failures in terms of probability estimates with known confidence limits. The PROFIT model, therefore, introduces an environmentalmore » and strain-rate dependent strain energy absorption to failure (SEAF) concept to account for the stress versus strain anomalies attributable to interstitial-disloction interaction effects in the Zircaloy cladding. Assuming that the power ramping rate is the operating corollary of strain-rate in the Zircaloy cladding, then the variables of first order importance in the PCI fuel failure phenomenon are postulated to be: 1. pre-transient fuel rod power, P{sub I}, 2. transient increase in fuel rod power, {Delta}P, 3. fuel burnup, Bu, and 4. the constitutive material property of the Zircaloy cladding, SEAF.« less

Failure on the American Board of Surgery Examinations of General Surgery Residency Graduates Correlates Positively with States' Malpractice Risk.

PubMed

Dent, Daniel L; Al Fayyadh, Mohammed J; Rawlings, Jeremy A; Hassan, Ramy A; Kempenich, Jason W; Willis, Ross E; Stewart, Ronald M

2018-03-01

It has been suggested that in environments where there is greater fear of litigation, resident autonomy and education is compromised. Our aim was to examine failure rates on American Board of Surgery (ABS) examinations in comparison with medical malpractice payments in 47 US states/territories that have general surgery residency programs. We hypothesized higher ABS examination failure rates for general surgery residents who graduate from residencies in states with higher malpractice risk. We conducted a retrospective review of five-year (2010-2014) pass rates of first-time examinees of the ABS examinations. States' malpractice data were adjusted based on population. ABS examinations failure rates for programs in states with above and below median malpractice payments per capita were 31 and 24 per cent (P < 0.01) respectively. This difference was seen in university and independent programs regardless of size. Pearson correlation confirmed a significant positive correlation between board failure rates and malpractice payments per capita for Qualifying Examination (P < 0.02), Certifying Examination (P < 0.02), and Qualifying and Certifying combined index (P < 0.01). Malpractice risk correlates positively with graduates' failure rates on ABS examinations regardless of program size or type. We encourage further examination of training environments and their relationship to surgical residency graduate performance.

40 CFR 51.352 - Basic I/M performance standard.

Code of Federal Regulations, 2010 CFR

2010-07-01

...% emission test failure rate among pre-1981 model year vehicles. (10) Waiver rate. A 0% waiver rate. (11... 20% emission test failure rate among pre-1981 model year vehicles. (11) Waiver rate. A 0% waiver rate... Requirements § 51.352 Basic I/M performance standard. (a) Basic I/M programs shall be designed and implemented...

40 CFR 51.352 - Basic I/M performance standard.

Code of Federal Regulations, 2014 CFR

2014-07-01

...% emission test failure rate among pre-1981 model year vehicles. (10) Waiver rate. A 0% waiver rate. (11... 20% emission test failure rate among pre-1981 model year vehicles. (11) Waiver rate. A 0% waiver rate... Requirements § 51.352 Basic I/M performance standard. (a) Basic I/M programs shall be designed and implemented...

40 CFR 51.352 - Basic I/M performance standard.

Code of Federal Regulations, 2011 CFR

2011-07-01

...% emission test failure rate among pre-1981 model year vehicles. (10) Waiver rate. A 0% waiver rate. (11... 20% emission test failure rate among pre-1981 model year vehicles. (11) Waiver rate. A 0% waiver rate... Requirements § 51.352 Basic I/M performance standard. (a) Basic I/M programs shall be designed and implemented...

40 CFR 51.352 - Basic I/M performance standard.

Code of Federal Regulations, 2012 CFR

2012-07-01

...% emission test failure rate among pre-1981 model year vehicles. (10) Waiver rate. A 0% waiver rate. (11... 20% emission test failure rate among pre-1981 model year vehicles. (11) Waiver rate. A 0% waiver rate... Requirements § 51.352 Basic I/M performance standard. (a) Basic I/M programs shall be designed and implemented...

40 CFR 51.352 - Basic I/M performance standard.

Code of Federal Regulations, 2013 CFR

2013-07-01

...% emission test failure rate among pre-1981 model year vehicles. (10) Waiver rate. A 0% waiver rate. (11... 20% emission test failure rate among pre-1981 model year vehicles. (11) Waiver rate. A 0% waiver rate... Requirements § 51.352 Basic I/M performance standard. (a) Basic I/M programs shall be designed and implemented...

The Endurant Stent Graft System: 15-month follow-up report in patients with challenging abdominal aortic anatomies.

PubMed

Hyhlik-Dürr, Alexander; Weber, Tim F; Kotelis, Drossos; Rengier, Fabian; Gahlen, Johannes; Böck, Stefanie; Köhler, Jürgen; Ratusinski, Christoph-M; Böckler, Dittmar

2011-08-01

The objective of this study is to report a 15-month follow-up with the Endurant Stent Graft System in patients with challenging aortic anatomies. At three German clinics, a consecutive series of 50 patients underwent endovascular abdominal aortic repair (EVAR) for challenging abdominal aortic aneurysm with the Endurant stent graft between November 2008 and May 2009. EVAR was elective in 48 cases and emergent in two. Patients had short (≤15 mm) aortic necks, severe suprarenal/infrarenal angulation, and/or small (<8 mm), calcified, severely angulated, or tortuous iliac or femoral access vessels. Additionally, a cohort of 40 patients without challenging anatomies were retrospectively analysed to clarify differences concerning technical success, mortality, and morbidity between these groups. The primary technical success rate was 92% (46/50). The 30-day mortality rate was 2% (1/50), the death due to multiorgan failure. Intraoperative angiograms revealed three type I endoleaks (2 proximal and 1 distal), and one of those was persisting at 30 days (30-day rate, 2%). Postoperative imaging discovered no further type I or type III endoleaks. The 30-day rate of the type II endoleak was 6% (3/50). There were two cases of graft limb occlusion, both requiring reintervention within 30 days. Follow-up was available in all of the 50 patients (100%) over a median of 15 months (1-25). During this time, seven patients died (overall mortality, 16%; 8/50), besides the above-described patient, all of them unrelated to the procedure. Compared to the 30-day results with the Endurant stent graft in non-challenging anatomies (no type I endoleak; no graft limb occlusion; all-cause mortality, 0%), procedure-related complications in challenging anatomies are increasing. Early and 15-month results with the Endurant stent graft in patients with challenging aortic anatomies are encouraging.

On rate-state and Coulomb failure models

USGS Publications Warehouse

Gomberg, J.; Beeler, N.; Blanpied, M.

2000-01-01

We examine the predictions of Coulomb failure stress and rate-state frictional models. We study the change in failure time (clock advance) Δt due to stress step perturbations (i.e., coseismic static stress increases) added to "background" stressing at a constant rate (i.e., tectonic loading) at time t0. The predictability of Δt implies a predictable change in seismicity rate r(t)/r0, testable using earthquake catalogs, where r0 is the constant rate resulting from tectonic stressing. Models of r(t)/r0, consistent with general properties of aftershock sequences, must predict an Omori law seismicity decay rate, a sequence duration that is less than a few percent of the mainshock cycle time and a return directly to the background rate. A Coulomb model requires that a fault remains locked during loading, that failure occur instantaneously, and that Δt is independent of t0. These characteristics imply an instantaneous infinite seismicity rate increase of zero duration. Numerical calculations of r(t)/r0 for different state evolution laws show that aftershocks occur on faults extremely close to failure at the mainshock origin time, that these faults must be "Coulomb-like," and that the slip evolution law can be precluded. Real aftershock population characteristics also may constrain rate-state constitutive parameters; a may be lower than laboratory values, the stiffness may be high, and/or normal stress may be lower than lithostatic. We also compare Coulomb and rate-state models theoretically. Rate-state model fault behavior becomes more Coulomb-like as constitutive parameter a decreases relative to parameter b. This is because the slip initially decelerates, representing an initial healing of fault contacts. The deceleration is more pronounced for smaller a, more closely simulating a locked fault. Even when the rate-state Δt has Coulomb characteristics, its magnitude may differ by some constant dependent on b. In this case, a rate-state model behaves like a modified Coulomb failure model in which the failure stress threshold is lowered due to weakening, increasing the clock advance. The deviation from a non-Coulomb response also depends on the loading rate, elastic stiffness, initial conditions, and assumptions about how state evolves.

UNDERSTANDING THE TECHNICAL AND SOCIAL REASONS FOR SOLAR BATTERY CHARGING SYSTEM FAILURES IN THAILAND. (U915644)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

25 CFR 30.122 - Must the Bureau assist a school it identified for school improvement, corrective action, or...

Code of Federal Regulations, 2010 CFR

2010-04-01

..., DEPARTMENT OF THE INTERIOR EDUCATION ADEQUATE YEARLY PROGRESS Failure To Make Adequate Yearly Progress § 30... restructuring, the Bureau must provide technical or other assistance described in 20 U.S.C. 6316(b)(4) and 20 U...

25 CFR 30.122 - Must the Bureau assist a school it identified for school improvement, corrective action, or...

Code of Federal Regulations, 2011 CFR

2011-04-01

..., DEPARTMENT OF THE INTERIOR EDUCATION ADEQUATE YEARLY PROGRESS Failure To Make Adequate Yearly Progress § 30... restructuring, the Bureau must provide technical or other assistance described in 20 U.S.C. 6316(b)(4) and 20 U...

High-Leverage Leadership: Improving Outcomes in Educational Settings

ERIC Educational Resources Information Center

Mongon, Denis; Chapman, Christopher

2011-01-01

Globalisation of world trade, international media, technological innovation and social change are creating opportunities and challenges that today's pupils will inherit and build on. A pupil's academic, technical and social capacity will define their success or failure. Therefore, educational outcomes and well-being for young people across…

Rule-Based Relaxation of Reference Identification Failures. Technical Report No. 396.

ERIC Educational Resources Information Center

Goodman, Bradley A.

In a step toward creating a robust natural language understanding system which detects and avoids miscommunication, this artificial intelligence research report provides a taxonomy of miscommunication problems that arise in expert-apprentice dialogues (including misunderstandings, wrong communication, and bad analogies), and proposes a flexible…

Erratum to Dynamic stresses, Coulomb failure, and remote triggering and to Surface wave potential for triggering tectonic (nonvolcanic) tremor

USGS Publications Warehouse

Hill, David P.

2012-01-01

Hill (2008) and Hill (2010) contain two technical errors: (1) a missing factor of 2 for computed Love‐wave amplitudes, and (2) a sign error in the off‐diagonal elements in the Euler rotation matrix.

Preschool Contracting: A Technical Assistance Guide. Revision.

ERIC Educational Resources Information Center

Kentucky State Dept. of Education, Frankfort.

This document presents information needed for development of contractual or cooperative arrangements between local school districts and other agencies and programs in Kentucky in order to better serve preschool children who are at risk of educational failure or who have identified disabilities. After an introductory section, the Preschool…

Mechanical Properties of Transgenic Silkworm Silk Under High Strain Rate Tensile Loading

NASA Astrophysics Data System (ADS)

Chu, J.-M.; Claus, B.; Chen, W.

2017-12-01

Studies have shown that transgenic silkworm silk may be capable of having similar properties of spider silk while being mass-producible. In this research, the tensile stress-strain response of transgenic silkworm silk fiber is systematically characterized using a quasi-static load frame and a tension Kolsky bar over a range of strain-rates between 10^{-3} and 700/s. The results show that transgenic silkworm silk tends to have higher overall ultimate stress and failure strain at high strain rate (700/s) compared to quasi-static strain rates, indicating rate sensitivity of the material. The failure strain at the high strain rate is higher than that of spider silk. However, the stress levels are significantly below that of spider silk, and far below that of high-performance fiber. Failure surfaces are examined via scanning electron microscopy and reveal that the failure modes are similar to those of spider silk.

Three-Dimensional Path Planning Software-Assisted Transjugular Intrahepatic Portosystemic Shunt: A Technical Modification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsauo, Jiaywei, E-mail: 80732059@qq.com; Luo, Xuefeng, E-mail: luobo-913@126.com; Ye, Linchao, E-mail: linchao.ye@siemens.com

2015-06-15

PurposeThis study was designed to report our results with a modified technique of three-dimensional (3D) path planning software assisted transjugular intrahepatic portosystemic shunt (TIPS).Methods3D path planning software was recently developed to facilitate TIPS creation by using two carbon dioxide portograms acquired at least 20° apart to generate a 3D path for overlay needle guidance. However, one shortcoming is that puncturing along the overlay would be technically impossible if the angle of the liver access set and the angle of the 3D path are not the same. To solve this problem, a prototype 3D path planning software was fitted with a utility to calculate themore » angle of the 3D path. Using this, we modified the angle of the liver access set accordingly during the procedure in ten patients.ResultsFailure for technical reasons occurred in three patients (unsuccessful wedged hepatic venography in two cases, software technical failure in one case). The procedure was successful in the remaining seven patients, and only one needle pass was required to obtain portal vein access in each case. The course of puncture was comparable to the 3D path in all patients. No procedure-related complication occurred following the procedures.ConclusionsAdjusting the angle of the liver access set to match the angle of the 3D path determined by the software appears to be a favorable modification to the technique of 3D path planning software assisted TIPS.« less

Treatment of type II endoleak using Onyx with long-term imaging follow-up.

PubMed

Khaja, Minhaj S; Park, Auh Whan; Swee, Warren; Evans, Avery J; Fritz Angle, J; Turba, Ulku C; Sabri, Saher S; Matsumoto, Alan H

2014-06-01

The purpose of our study is to report our experience with the use of an ethylene vinyl alcohol copolymer (Onyx) in an off-label fashion for the treatment of type II endoleak after endovascular repair of the thoracic (TEVAR) and abdominal (EVAR) aorta. A retrospective review of patients with type I and/or II endoleak treated with Onyx was performed. Data regarding the technical, clinical, and imaging outcomes were collected. Technical success was defined as decreased or eliminated endoleak on the first imaging follow-up. Clinical success was defined as unchanged or decreased aneurysm sac size on subsequent follow-up. Eighteen patients (15 male, 3 female) with a mean age of 79 years (range 69-92) met inclusion criteria (16 abdominal aortic aneurysm, 2 thoracic aortic aneurysm). Sixteen patients had type II endoleak, and 2 had complex type II endoleak with a type I component. The interval between endograft placement and treatment was a mean of 30 months. Direct sac treatment approach was used in 13 patients; transarterial approach was used in 3 patients. Seven patients required the use of coils, N-butyl cyanoacrylate glue, or Amplatzer vascular plugs. The average volume of Onyx used per treatment was 5.6 mL (range 2.5-13). Duration of imaging follow-up was 0.75-72.5 months (mean 32.8). Sixteen of 18 (88.9 %) patients had initial technical and clinical success. Two of 18 patients (11.1 %) were initial technical failures, and 1 remained a failure despite a second treatment and attempted surgical ligation. Eight of 18 (44.4 %) of patients eventually required a second intervention, 5 (27.8 %) of them due to delayed clinical failure. Complications included 1 psoas hematoma, 1 transient L2 nerve paresis, and 1 intraperitoneal Onyx leak; all of these were without clinical sequelae. Onyx with or without coil/glue/Amplatzer plug embolization is safe and useful in the treatment of type II endoleak after TEVAR and EVAR. However, long-term clinical and imaging follow-up is needed for early detection and management of recurrence of the primary endoleak or the development of new, secondary endoleaks or enlargement of the aneurysm sac.

Vocal fold tissue failure: preliminary data and constitutive modeling.

PubMed

Chan, Roger W; Siegmund, Thomas

2004-08-01

In human voice production (phonation), linear small-amplitude vocal fold oscillation occurs only under restricted conditions. Physiologically, phonation more often involves large-amplitude oscillation associated with tissue stresses and strains beyond their linear viscoelastic limits, particularly in the lamina propria extracellular matrix (ECM). This study reports some preliminary measurements of tissue deformation and failure response of the vocal fold ECM under large-strain shear The primary goal was to formulate and test a novel constitutive model for vocal fold tissue failure, based on a standard-linear cohesive-zone (SL-CZ) approach. Tissue specimens of the sheep vocal fold mucosa were subjected to torsional deformation in vitro, at constant strain rates corresponding to twist rates of 0.01, 0.1, and 1.0 rad/s. The vocal fold ECM demonstrated nonlinear stress-strain and rate-dependent failure response with a failure strain as low as 0.40 rad. A finite-element implementation of the SL-CZ model was capable of capturing the rate dependence in these preliminary data, demonstrating the model's potential for describing tissue failure. Further studies with additional tissue specimens and model improvements are needed to better understand vocal fold tissue failure.

Control system failure monitoring using generalized parity relations. M.S. Thesis Interim Technical Report

NASA Technical Reports Server (NTRS)

Vanschalkwyk, Christiaan Mauritz

1991-01-01

Many applications require that a control system must be tolerant to the failure of its components. This is especially true for large space-based systems that must work unattended and with long periods between maintenance. Fault tolerance can be obtained by detecting the failure of the control system component, determining which component has failed, and reconfiguring the system so that the failed component is isolated from the controller. Component failure detection experiments that were conducted on an experimental space structure, the NASA Langley Mini-Mast are presented. Two methodologies for failure detection and isolation (FDI) exist that do not require the specification of failure modes and are applicable to both actuators and sensors. These methods are known as the Failure Detection Filter and the method of Generalized Parity Relations. The latter method was applied to three different sensor types on the Mini-Mast. Failures were simulated in input-output data that were recorded during operation of the Mini-Mast. Both single and double sensor parity relations were tested and the effect of several design parameters on the performance of these relations is discussed. The detection of actuator failures is also treated. It is shown that in all the cases it is possible to identify the parity relations directly from input-output data. Frequency domain analysis is used to explain the behavior of the parity relations.

EASEPort NPWT System to Enhance Skin Graft Survival--A Simple Assembly.

PubMed

Prasetyono, Theddeus O H; Rini, Irena Sakura; Wibisono, Cindy

2015-03-01

Skin graft has been known to be prone to failure. This study was aimed to make a simplification of the negative pressure wound therapy (NPWT), which follows EASEPort (effective, affordable, safe, easily handled, and portable) concept to support the take of skin graft. The design of the EASEPort-NPWT was then made and technically verified. Thereafter, an animal experimental study comparing the EASEPort-NPWT to the classic tie-over technique on skin graft over exudative wound was conducted. The EASEPort-NPWT was verified to be able to yield and sustain the subatmospheric pressure needed. In the animal study, the treatment group showed better skin graft survival rate (97.55 ± 11.18% take) than the control group (54.88 ± 19.73%) on day-7. Histopathology examination showed good quality of the skin structures taken from the treatment group, which was better than the structures of the skin in the control group. In summary, this study has been able to fulfill its objective to create a device following EASEPort concept. Subsequently, the EASEPort-NPWT was able to enhance skin graft survival rate in exudative wound.

[Rage against the machine -- necessity of robotic assisted prostatectomy].

PubMed

Friedrich, M; Steiner, T; Popken, G

2013-03-01

During the last decade urologists have faced a dramatic increase in robotic surgery. Despite the exceptional acceptance of this technique there is a complete lack of evidence for the equi-efficacy or superiority of this technique compared to open or laparoscopic prostatectomy. There is now an increasing body of evidence for the evaluation of robotic assisted prostatectomy. Robotic assisted prostatectomy is a safe procedure. The rate of technical failure is small. The rate of surgical complications is comparable with that of open or conventional laparoscopic prostatectomy. Similar to the conventional laparoscopic prostatectomy there is a trend for a minor blood loss and a smaller transfusion rate compared to the retropubic approach. In recent meta-analyses there is no advatage regarding the oncological or functional outcome for robotic prostatectomy. Neither the rate of positive surgical margins nor the rate of biochemical recurrence favours robotic prostatectomy. Regarding functional outcome some publications describe better results for urinary and sexual function for robotic surgery. Careful evaluation of these data reveals a low level of evidence due to a strong bias in favour of robotic surgery. In contrast, recent analysis of "Medicare" data reveal a considerable poorer urinary function after robotic prostatectomy compared to open retropubic prostatectomy. The Urological Board of the Helios Hospital Group does not recommend the use of a robotic device for radical prostatectomy. © Georg Thieme Verlag KG Stuttgart · New York.

Stent placement with the monorail technique for treatment of mesenteric artery stenosis.

PubMed

Schaefer, Philipp J; Schaefer, Fritz K W; Hinrichsen, Holger; Jahnke, Thomas; Charalambous, Nikolas; Heller, Martin; Mueller-Huelsbeck, Stefan

2006-04-01

To analyze the immediate and midterm success of stenting of mesenteric arteries by a monorail technique in patients with chronic mesenteric ischemia. In this prospective case series, 19 patients (11 male, 8 female; mean age, 62.9 +/- 10.4 y; range, 36-82 y) with 23 symptomatic stenoses of mesenteric arteries were treated with stent placement by a monorail technique in a radiologic intervention center over a period of 4.5 years. Clinical examinations and duplex sonography were used to evaluate the stents' patency and clinical success. Kaplan-Meier graphs were calculated to analyze the patency and freedom-from-symptom rate. Initial technical success rate was 22/23 (96%). Mean follow-up was 17 months (range, 1-58 mo). Primary patency and primary clinical success rates were 82% and 78%, respectively. According to Kaplan-Meier tables, the patency rates were 96%, 87%, 76%, and 61% at 0, 1, 15, and 24 months, respectively, and the freedom-from-symptom rates were 95%, 90%, 72%, and 54% at 0, 1, 24, and 30 months, respectively. No peri-interventional complications occurred. Two patients died of cardiac failure in the hospital within 30 days after intervention; deaths were not related to the intervention. Stent placement by a monorail technique in mesenteric arteries is an effective and safe treatment for symptomatic stenoses in patients with chronic mesenteric ischemia after a mean follow-up of 17 months.

Failure to Rescue, Rescue Surgery and Centralization of Postoperative Complications: A Challenge for General and Acute Care Surgeons.

PubMed

Zago, Mauro; Bozzo, Samantha; Carrara, Giulia; Mariani, Diego

2017-01-01

To explore the current literature on the failure to rescue and rescue surgery concepts, to identify the key items for decreasing the failure to rescue rate and improve outcome, to verify if there is a rationale for centralization of patients suffering postoperative complications. There is a growing awareness about the need to assess and measure the failure to rescue rate, on institutional, regional and national basis. Many factors affect failure to rescue, and all should be individually analyzed and considered. Rescue surgery is one of these factors. Rescue surgery assumes an acute care surgery background. Measurement of failure to rescue rate should become a standard for quality improvement programs. Implementation of all clinical and organizational items involved is the key for better outcomes. Preparedness for rescue surgery is a main pillar in this process. Centralization of management, audit, and communication are important as much as patient centralization. Celsius.

The choices before us.

PubMed

Streeten, P P

1980-01-01

This introduction is from the 16th World Conference of SID in Colombo, Sri Lanka, August 1979, which addressed the theme of development choices for the 1980's and beyond. Choices may refer to different political, ideological or social systems. Choices may refer to strategies and technical issues, e.g. agriculture vs. industry. A third meaning of choice is implicit in the idea of a Third World, or alternative, method of development. The third meaning implies a rejection of Western institutions, values, and standards. In the past, the transfer of Western or in this case Northern, institutions and standards has disappointed and created obstacles to development. The rapid rate of population growth forces choices of population control and resource management. Common themes of development have emerged from conference discussions: the need to build development efforts on indigenous values; the need for new institutions both at the sub-national and at the super-national level; and, the need to adjust to inevitable changes rationally and with foresight. The nation state is too large for many functions that are better decentralized and left to village or district administrations, yet it is too small to respond to global challenges and environmental risks like harvest failure, credit risks, marketing risks, failure of supplies. The interests of the state are not identical with those of society or particular groups in society.

Should Jehovah's Witness patients be listed for heart transplantation?

PubMed

Elmistekawy, Elsayed; Mesana, Thierry G; Ruel, Marc

2012-10-01

This best evidence topic in Cardiac Surgery was written according to a structured protocol. The question addressed was: for [Jehovah's Witness patients with end-stage heart failure] can these patients undergo a [heart transplantation] without an increased rate of mortality. Altogether, 133 papers were found using the reported search strategy. Of those, 29 papers represented the best evidence to answer the clinical question. Five papers focusing on patients of the Jehovah's Witness (JW) faith who had end-stage heart failure were published. Successful heart transplantation was performed in a total of seven patients without mortality, re-exploration or blood transfusion. One patient had left ventricular reduction surgery twice and another patient had bypass surgery several years after transplantation. Other successful organ transplantations were also reported, including lung, liver, kidney and pancreas in both adult and paediatric patients of the JW faith, with comparable mortality and morbidity to non-JW patients. A publication bias is likely; nevertheless, we conclude that although there are no large studies directly focused on heart transplantation in JW patients, a multidisciplinary team approach to such surgery can make it technically feasible and without an increased mortality risk in suitable candidates. Therefore, such patients may be considered for heart transplantation under selected and favourable circumstances.

Final Report for Project 13-4791: New Mechanistic Models of Creep-Fatigue Crack Growth Interactions for Advanced High Temperature Reactor Components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruzic, Jamie J; Siegmund, Thomas; Tomar, Vikas

This project developed and validated a novel, multi-scale, mechanism-based model to quantitatively predict creep-fatigue crack growth and failure for Ni-based Alloy 617 at 800°C. Alloy 617 is a target material for intermediate heat exchangers in Generation IV very high temperature reactor designs, and it is envisioned that this model will aid in the design of safe, long lasting nuclear power plants. The technical effectiveness of the model was shown by demonstrating that experimentally observed crack growth rates can be predicted under both steady state and overload crack growth conditions. Feasibility was considered by incorporating our model into a commercially availablemore » finite element method code, ABAQUS, that is commonly used by design engineers. While the focus of the project was specifically on an alloy targeted for Generation IV nuclear reactors, the benefits to the public are expected to be wide reaching. Indeed, creep-fatigue failure is a design consideration for a wide range of high temperature mechanical systems that rely on Ni-based alloys, including industrial gas power turbines, advanced ultra-super critical steam turbines, and aerospace turbine engines. It is envisioned that this new model can be adapted to a wide range of engineering applications.« less

Novel Solution for Massive Glenoid Defects in Shoulder Arthroplasty: A Patient-Specific Glenoid Vault Reconstruction System.

PubMed

Dines, David M; Gulotta, Lawrence; Craig, Edward V; Dines, Joshua S

Complex glenoid deformities present the most difficult challenges in shoulder arthroplasty. These deformities may be caused by severe degenerative or congenital deformity, posttraumatic anatomy, tumor, or, in most cases, bone loss after glenoid failure in anatomical total shoulder arthroplasty. Methods of treating severe bone loss have included inlay and onlay bone-graft options with augmented fixation and, in severe cases, salvage hemiarthroplasty with limited goal expectations. Unfortunately, none of these methods has provided consistently satisfactory reproducible results. In fact, each has had high rates of failure and complications. Borrowing from hip and knee arthroplasty surgeons' experience in using CAD/CAM (computer-aided design/computer-aided manufacturing) patient-specific implants to fill significant bony defects, Dr. D. M. Dines developed a glenoid vault reconstruction system (VRS) in conjunction with the Comprehensive Shoulder Arthroplasty System (Zimmer Biomet) to treat severe glenoid bone deficiency. The VRS is patient-specific; each case involves making a preoperative plan based on 3-dimensional reconstruction of a 2-dimensional computed tomography scan. The patient-specific implant and instrumentation that are created are used to reconstruct the deformed glenoid in an anatomical position without the need for additional bone graft. In this article, we describe the implant and its indications, technical aspects of production, and surgical technique.

Failure Rates of Orthodontic Fixed Lingual Retainers bonded with Two Flowable Light-cured Adhesives: A Comparative Prospective Clinical Trial.

PubMed

Talic, Nabeel F

2016-08-01

This comparative prospective randomized clinical trial examined the in vivo failure rates of fixed mandibular and maxillary lingual retainers bonded with two light-cured flowable composites over 6 months. Consecutive patients were divided into two groups on a 1:1 basis. Two hundred fixed lingual retainers were included, and their failures were followed for 6 months. One group (n = 50) received retainers bonded with a nano-hybrid composite based on nano-optimized technology (Tetric-N-Flow, Ivoclar Vivadent). Another group (n = 50) received retainers bonded with a low viscosity (LV) composite (Transbond Supreme LV, 3M Unitek). There was no significant difference between the overall failure rates of mandibular retainers bonded with Transbond (8%) and those bonded with Tetric-N-Flow (18%). However, the odds ratio for failure using Tetric-N-flow was 2.52-fold greater than that of Transbond. The failure rate of maxillary retainers bonded with Transbond was higher (14%), but not significantly different, than that of maxillary retainers bonded with Tetric-N-flow (10%). There was no significant difference in the estimated mean survival times of the maxillary and mandibular retainers bonded with the two composites. Both types of composites tested in the current study can be used to bond fixed maxillary and mandibular lingual retainers, with low failure rates.

Multimodal activity monitoring for home rehabilitation of geriatric fracture patients--feasibility and acceptance of sensor systems in the GAL-NATARS study.

PubMed

Marschollek, Michael; Becker, Marcus; Bauer, Jürgen M; Bente, Petra; Dasenbrock, Lena; Elbers, Katharina; Hein, Andreas; Kolb, Gerald; Künemund, Harald; Lammel-Polchau, Christopher; Meis, Markus; Meyer Zu Schwabedissen, Hubertus; Remmers, Hartmut; Schulze, Mareike; Steen, Enno-Edzard; Thoben, Wilfried; Wang, Ju; Wolf, Klaus-Hendrik; Haux, Reinhold

2014-01-01

Demographic change will lead to a diminishing care workforce faced with rising numbers of older persons in need of care, suggesting meaningful use of health-enabling technologies, and home monitoring in particular, to contribute to supporting both the carers and the persons in need. We present and discuss the GAL-NATARS study design along with first results regarding technical feasibility of long-term home monitoring and acceptance of different sensor modalities. Fourteen geriatric participants with mobility-impairing fractures were recruited in three geriatric clinics. Following inpatient geriatric rehabilitation, their homes were equipped with ambient sensor components for three months. Additionally, a wearable accelerometer was employed. Technical feasibility was assessed by system and component downtimes, technology acceptance by face-to-face interviews. The overall system downtime was 6%, effected by two single events, but not by software failures. Technology acceptance was rated very high by all participants at the end of the monitoring periods, and no interference with their social lives was reported. Home-monitoring technologies were well-accepted by our participants. The information content of the data still needs to be evaluated with regard to clinical outcome parameters as well as the effect on the quality of life before recommending large-scale implementations.

Emergency endotracheal intubation under fluoroscopy guidance for patients with acute dyspnea or asphyxia.

PubMed

Jiao, Dechao; Xie, Na; Han, Xinwei; Wu, Gang

2016-11-01

To evaluate the feasibility and effectiveness of emergency endotracheal intubation (EEI) under fluoroscopy guidance for patients with acute dyspnea or asphyxia. From October 2011 to October 2014, of 1521 patients with acute dyspnea or asphyxia who required EEI in 6 departments, 43 patients who experienced intubation difficulty or failure were entered into this study. Data on technical success, procedure time, complications, and clinical outcome were collected. The pulse oxygen saturation and Hugh-Jones classification changes were analyzed. Fluoroscopy-guided EEI was technically successful in all patients. Acute dyspnea had resolved in all patients with clinical success rate 100% after the procedure. There were no serious complications during or after the procedure. The pulse oxygen saturation and Hugh-Jones classification showed significant increase after EEI (P < .05). Further treatments, including tracheal stents (n = 21), surgical resection (n = 16), palliative tracheotomy (n = 4), and bronchoscopic treatment (n = 2), were performed 1 to 72 hours after EEI. During a mean follow-up period of 13.2 months, 13 patients had died and 30 patients remained alive without dyspnea. Fluoroscopy-guided EEI is a safe and feasible procedure, and may serve as an alternative treatment option for patients when traditional EEI is unsuccessful. Copyright © 2016 Elsevier Inc. All rights reserved.

European external quality control study on the competence of laboratories to recognize rare sequence variants resulting in unusual genotyping results.

PubMed

Márki-Zay, János; Klein, Christoph L; Gancberg, David; Schimmel, Heinz G; Dux, László

2009-04-01

Depending on the method used, rare sequence variants adjacent to the single nucleotide polymorphism (SNP) of interest may cause unusual or erroneous genotyping results. Because such rare variants are known for many genes commonly tested in diagnostic laboratories, we organized a proficiency study to assess their influence on the accuracy of reported laboratory results. Four external quality control materials were processed and sent to 283 laboratories through 3 EQA organizers for analysis of the prothrombin 20210G>A mutation. Two of these quality control materials contained sequence variants introduced by site-directed mutagenesis. One hundred eighty-nine laboratories participated in the study. When samples gave a usual result with the method applied, the error rate was 5.1%. Detailed analysis showed that more than 70% of the failures were reported from only 9 laboratories. Allele-specific amplification-based PCR had a much higher error rate than other methods (18.3% vs 2.9%). The variants 20209C>T and [20175T>G; 20179_20180delAC] resulted in unusual genotyping results in 67 and 85 laboratories, respectively. Eighty-three (54.6%) of these unusual results were not recognized, 32 (21.1%) were attributed to technical issues, and only 37 (24.3%) were recognized as another sequence variant. Our findings revealed that some of the participating laboratories were not able to recognize and correctly interpret unusual genotyping results caused by rare SNPs. Our study indicates that the majority of the failures could be avoided by improved training and careful selection and validation of the methods applied.

Near Field Communication-based telemonitoring with integrated ECG recordings.

PubMed

Morak, J; Kumpusch, H; Hayn, D; Leitner, M; Scherr, D; Fruhwald, F M; Schreier, G

2011-01-01

Telemonitoring of vital signs is an established option in treatment of patients with chronic heart failure (CHF). In order to allow for early detection of atrial fibrillation (AF) which is highly prevalent in the CHF population telemonitoring programs should include electrocardiogram (ECG) signals. It was therefore the aim to extend our current home monitoring system based on mobile phones and Near Field Communication technology (NFC) to enable patients acquiring their ECG signals autonomously in an easy-to-use way. We prototypically developed a sensing device for the concurrent acquisition of blood pressure and ECG signals. The design of the device equipped with NFC technology and Bluetooth allowed for intuitive interaction with a mobile phone based patient terminal. This ECG monitoring system was evaluated in the course of a clinical pilot trial to assess the system's technical feasibility, usability and patient's adherence to twice daily usage. 21 patients (4f, 54 ± 14 years) suffering from CHF were included in the study and were asked to transmit two ECG recordings per day via the telemonitoring system autonomously over a monitoring period of seven days. One patient dropped out from the study. 211 data sets were transmitted over a cumulative monitoring period of 140 days (overall adherence rate 82.2%). 55% and 8% of the transmitted ECG signals were sufficient for ventricular and atrial rhythm assessment, respectively. Although ECG signal quality has to be improved for better AF detection the developed communication design of joining Bluetooth and NFC technology in our telemonitoring system allows for ambulatory ECG acquisition with high adherence rates and system usability in heart failure patients.

Better treatment strategies for patients with acute cholecystitis and American Society of Anesthesiologists classification 3 or greater.

PubMed

Yun, Sung Su; Hwang, Dae Wook; Kim, Se Won; Park, Sang Hwan; Park, Sang Jin; Lee, Dong Shick; Kim, Hong Jin

2010-07-01

Laparoscopic cholecystectomy is the best treatment choice for acute cholecystitis. However, it still carries high conversion and mortality rates. The purpose of this study was to find out better treatment strategies for high surgical risk patients with acute cholecystitis. Between January 2002 and June 2008, we performed percutaneous cholecystostomy instead of emergency cholecystectomy in 44 patients with acute cholecystitis and American Society of Anesthesiologists (ASA) classification 3 or greater. This was performed in 31 patients as a bridge procedure before elective cholecystectomy (bridge group) and as a palliative procedure in 11 patients (palliation group). The mean age of patients was 71.6 years (range 52-86 years). The mean ASA classifications before and after percutaneous cholecystostomy were 3.3 +/- 0.5 and 2.5 +/- 0.6, respectively, in the bridge group, and 3.6 +/- 0.7 and 3.1 +/- 1.0, in the palliation group, respectively. Percutaneous cholecystostomy was technically successful in all patients. There were two deaths after percutaneous cholecystostomy in the palliation group due to underlying ischemic heart disease and multiple organ failure. Resumption of oral intake was possible 2.9 +/- 1.8 days in the bridge group and 3.9 +/- 3.5 days in the palliation group after percutaneous cholecystostomy. We attempted 17 laparoscopic cholecystectomies and experienced one failure due to bile duct injury (success rate: 94.1%). The postoperative course of all cholecystectomy patients was uneventful. Percutaneous cholecystostomy is an effective bridge procedure before cholecystectomy in patients with acute cholecystitis and ASA classification 3 or greater.

Novel Corrosion Sensor for Vision 21 Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heng Ban; Bharat Soni

2007-03-31

Advanced sensor technology is identified as a key component for advanced power systems for future energy plants that would have virtually no environmental impact. This project intends to develop a novel high temperature corrosion sensor and subsequent measurement system for advanced power systems. Fireside corrosion is the leading mechanism for boiler tube failures and has emerged to be a significant concern for current and future energy plants due to the introduction of technologies targeting emissions reduction, efficiency improvement, or fuel/oxidant flexibility. Corrosion damage can lead to catastrophic equipment failure, explosions, and forced outages. Proper management of corrosion requires real-time indicationmore » of corrosion rate. However, short-term, on-line corrosion monitoring systems for fireside corrosion remain a technical challenge to date due to the extremely harsh combustion environment. The overall goal of this project is to develop a technology for on-line fireside corrosion monitoring. This objective is achieved by the laboratory development of sensors and instrumentation, testing them in a laboratory muffle furnace, and eventually testing the system in a coal-fired furnace. This project successfully developed two types of sensors and measurement systems, and successful tested them in a muffle furnace in the laboratory. The capacitance sensor had a high fabrication cost and might be more appropriate in other applications. The low-cost resistance sensor was tested in a power plant burning eastern bituminous coals. The results show that the fireside corrosion measurement system can be used to determine the corrosion rate at waterwall and superheater locations. Electron microscope analysis of the corroded sensor surface provided detailed picture of the corrosion process.« less

Sensitivity analysis by approximation formulas - Illustrative examples. [reliability analysis of six-component architectures

NASA Technical Reports Server (NTRS)

White, A. L.

1983-01-01

This paper examines the reliability of three architectures for six components. For each architecture, the probabilities of the failure states are given by algebraic formulas involving the component fault rate, the system recovery rate, and the operating time. The dominant failure modes are identified, and the change in reliability is considered with respect to changes in fault rate, recovery rate, and operating time. The major conclusions concern the influence of system architecture on failure modes and parameter requirements. Without this knowledge, a system designer may pick an inappropriate structure.

Comparison between mixed and laminar airflow systems in operating rooms and the influence of human factors: experiences from a Swedish orthopedic center.

PubMed

Erichsen Andersson, Annette; Petzold, Max; Bergh, Ingrid; Karlsson, Jón; Eriksson, Bengt I; Nilsson, Kerstin

2014-06-01

The importance of laminar airflow systems in operating rooms as protection from surgical site infections has been questioned. The aim of our study was to explore the differences in air contamination rates between displacement ventilation and laminar airflow systems during planned and acute orthopedic implant surgery. A second aim was to compare the influence of the number of people present, the reasons for traffic flow, and the door-opening rates between the 2 systems. Active air sampling and observations were made during 63 orthopedic implant operations. The laminar airflow system resulted in a reduction of 89% in colony forming units in comparison with the displacement system (P < .001). The air samples taken in the preparation rooms showed high levels of bacterial growth (≈ 40 CFU/m(3)). Our study shows that laminar airflow-ventilated operating rooms offer high-quality air during surgery, with very low levels of colony forming units close to the surgical wound. The continuous maintenance of laminar air flow and other technical systems are crucial, because minor failures in complex systems like those in operating rooms can result in a detrimental effect on air quality and jeopardize the safety of patients. The technical ventilation solutions are important, but they do not guarantee clean air, because many other factors, such as the organization of the work and staff behavior, influence air cleanliness. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Remote operation of an orbital maneuvering vehicle in simulated docking maneuvers

NASA Technical Reports Server (NTRS)

Brody, Adam R.

1990-01-01

Simulated docking maneuvers were performed to assess the effect of initial velocity on docking failure rate, mission duration, and delta v (fuel consumption). Subjects performed simulated docking maneuvers of an orbital maneuvering vehicle (OMV) to a space station. The effect of the removal of the range and rate displays (simulating a ranging instrumentation failure) was also examined. Naive subjects were capable of achieving a high success rate in performing simulated docking maneuvers without extensive training. Failure rate was a function of individual differences; there was no treatment effect on failure rate. The amount of time subjects reserved for final approach increased with starting velocity. Piloting of docking maneuvers was not significantly affected in any way by the removal of range and rate displays. Radial impulse was significant both by subject and by treatment. NASA's 0.1 percent rule, dictating an approach rate no greater than 0.1 percent of the range, is seen to be overly conservative for nominal docking missions.

Analysis of factors affecting failure of glass cermet tunnel restorations in a multi-center study.

PubMed

Pilebro, C E; van Dijken, J W

2001-06-01

The aim of this study was to analyze factors influencing the failures of tunnel restorations performed with a glass cermet cement (Ketac Silver). Caries activity, lesion size, tunnel cavity opening size, partial or total tunnel, composite lamination or operating time showed no significant correlation to failure rate. Twelve dentists in eight clinics clinically experienced and familiar with the tunnel technique placed 374 restorations. The occlusal sections of fifty percent of the restorations were laminated with hybrid resin composite. The results of the yearly clinical and radiographic evaluations over the course of 3 years were correlated to factors that could influence the failure rate using logistic regression analysis. At the 3-year recall a cumulative number of 305 restorations were available. The cumulative replacement rate was 20%. The main reasons for replacement were marginal ridge fracture (14%) and dentin caries (3%). Another 7% of the restorations which had not been replaced were classified as failures because of untreated dentin caries. The only significant variable observed was the individual failure rate of the participating dentists varying between 9 and 50% (p=0.013).

Increase in hospital admission rates for heart failure in The Netherlands, 1980-1993.

PubMed Central

Reitsma, J. B.; Mosterd, A.; de Craen, A. J.; Koster, R. W.; van Capelle, F. J.; Grobbee, D. E.; Tijssen, J. G.

1996-01-01

OBJECTIVE: To study the trend in hospital admission rates for heart failure in the Netherlands from 1980 to 1993. DESIGN: All hospital admissions in the Netherlands with a principal discharge diagnosis of heart failure were analysed. In addition, individual records of heart failure patients from a subset of 7 hospitals were analysed to estimate the frequency and timing of readmissions. RESULTS: The total number of discharges for men increased from 7377 in 1980 to 13 022 in 1993, and for women from 7064 to 12 944. From 1980 through 1993 age adjusted discharge rates rose 48% for men and 40% for women. Age adjusted in-hospital mortality for heart failure decreased from 19% in 1980 to 15% in 1993. For all age groups in-hospital mortality for men was higher than for women. The mean length of hospital admissions in 1993 was 14.0 days for men and 16.4 days for women. A review of individual patient records from a 6.3% sample of all hospital admissions in the Netherlands indicated that within a 2 year period 18% of the heart failure patients were admitted more than once and 5% more than twice. CONCLUSIONS: For both men and women a pronounced increase in age adjusted discharge rates for heart failure was observed in the Netherlands from 1980 to 1993. Readmissions were a prominent feature among heart failure patients. Higher survival rates after acute myocardial infarction and the longer survival of patients with heart disease, including heart failure may have contributed to the observed increase. The importance of advances in diagnostic tools and of possible changes in admission policy remain uncertain. PMID:8944582

First time description of early lead failure of the Linox Smart lead compared to other contemporary high-voltage leads.

PubMed

Weberndörfer, Vanessa; Nyffenegger, Tobias; Russi, Ian; Brinkert, Miriam; Berte, Benjamin; Toggweiler, Stefan; Kobza, Richard

2018-05-01

Early lead failure has recently been reported in ICD patients with Linox SD leads. We aimed to compare the long-term performance of the following lead model Linox Smart SD with other contemporary high-voltage leads. All patients receiving high-voltage leads at our center between November 2009 and May 2017 were retrospectively analyzed. Lead failure was defined as the occurrence of one or more of the following: non-physiological high-rate episodes, low- or high-voltage impedance anomalies, undersensing, or non-capture. In total, 220 patients were included (Linox Smart SD, n = 113; contemporary lead, n = 107). During a median follow-up of 3.8 years (IQR 1.6-5.9 years), a total of 16 (14 in Linox Smart SD and 2 in contemporary group) lead failures occurred, mostly due to non-physiological high-rate sensing or impedance abnormalities. Lead failure incidence rates per 100 person-years were 2.9 (95% CI 1.7-4.9) and 0.6 (95% CI 0.1-2.3) for Linox Smart SD compared to contemporary leads respectively. Kaplan Meier estimates of 5-year lead failure rates were 14.0% (95% CI 8.1-23.6%) and 1.3% (95% CI 0.2-8.9%), respectively (log-rank p = 0.028). Implantation of a Linox Smart SD lead increased the risk of lead failure with a hazard ratio (HR) of 4.53 (95% CI 1.03-19.95, p = 0.046) and 4.44 (95% CI 1.00-19.77, p = 0.05) in uni- and multivariable Cox models. The new Linox Smart SD lead model was associated with high failure rates and should be monitored closely to detect early signs of lead failure.

Failure to activate the in-hospital emergency team: causes and outcomes.

PubMed

Barbosa, Vera; Gomes, Ernestina; Vaz, Senio; Azevedo, Gustavo; Fernandes, Gonçalo; Ferreira, Amélia; Araujo, Rui

2016-01-01

To determine the incidence of afferent limb failure of the in-hospital Medical Emergency Team, characterizing it and comparing the mortality between the population experiencing afferent limb failure and the population not experiencing afferent limb failure. A total of 478 activations of the Medical Emergency Team of Hospital Pedro Hispano occurred from January 2013 to July 2015. A sample of 285 activations was obtained after excluding incomplete records and activations for patients with less than 6 hours of hospitalization. The sample was divided into two groups: the group experiencing afferent limb failure and the group not experiencing afferent limb failure of the Medical Emergency Team. Both populations were characterized and compared. Statistical significance was set at p ≤ 0.05. Afferent limb failure was observed in 22.1% of activations. The causal analysis revealed significant differences in Medical Emergency Team activation criteria (p = 0.003) in the group experiencing afferent limb failure, with higher rates of Medical Emergency Team activation for cardiac arrest and cardiovascular dysfunction. Regarding patient outcomes, the group experiencing afferent limb failure had higher immediate mortality rates and higher mortality rates at hospital discharge, with no significant differences. No significant differences were found for the other parameters. The incidence of cardiac arrest and the mortality rate were higher in patients experiencing failure of the afferent limb of the Medical Emergency Team. This study highlights the need for health units to invest in the training of all healthcare professionals regarding the Medical Emergency Team activation criteria and emergency medical response system operations.

The failure of earthquake failure models

USGS Publications Warehouse

Gomberg, J.

2001-01-01

In this study I show that simple heuristic models and numerical calculations suggest that an entire class of commonly invoked models of earthquake failure processes cannot explain triggering of seismicity by transient or "dynamic" stress changes, such as stress changes associated with passing seismic waves. The models of this class have the common feature that the physical property characterizing failure increases at an accelerating rate when a fault is loaded (stressed) at a constant rate. Examples include models that invoke rate state friction or subcritical crack growth, in which the properties characterizing failure are slip or crack length, respectively. Failure occurs when the rate at which these grow accelerates to values exceeding some critical threshold. These accelerating failure models do not predict the finite durations of dynamically triggered earthquake sequences (e.g., at aftershock or remote distances). Some of the failure models belonging to this class have been used to explain static stress triggering of aftershocks. This may imply that the physical processes underlying dynamic triggering differs or that currently applied models of static triggering require modification. If the former is the case, we might appeal to physical mechanisms relying on oscillatory deformations such as compaction of saturated fault gouge leading to pore pressure increase, or cyclic fatigue. However, if dynamic and static triggering mechanisms differ, one still needs to ask why static triggering models that neglect these dynamic mechanisms appear to explain many observations. If the static and dynamic triggering mechanisms are the same, perhaps assumptions about accelerating failure and/or that triggering advances the failure times of a population of inevitable earthquakes are incorrect.

Online Testing Suffers Setbacks in Multiple States

ERIC Educational Resources Information Center

Davis, Michelle R.

2013-01-01

Widespread technical failures and interruptions of recent online testing in a number of states have shaken the confidence of educators and policymakers in high-tech assessment methods and raised serious concerns about schools' technological readiness for the coming common-core online tests. The glitches arose as many districts in the 46 states…

45 CFR 305.62 - Disregard of a failure which is of a technical nature.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., DEPARTMENT OF HEALTH AND HUMAN SERVICES PROGRAM PERFORMANCE MEASURES, STANDARDS, FINANCIAL INCENTIVES, AND... adversely affect the performance of the State's IV-D program or does not adversely affect the determination of the level of the State's paternity establishment or other performance measures percentages. ...

The Cult of Technical Rationality.

ERIC Educational Resources Information Center

Hansel, John L.

1985-01-01

Argues that the decline in the competitiveness of American industries arises from a failure to innovate in quality management rather than from a decline in product quality. Discusses the superiority of the U.S. in generating technological innovations and its lag in the commercialization of the fruits of that technology. (HB)

"Future Proofing" Faculty: The Struggle To Create Technical Lifelong Learners.

ERIC Educational Resources Information Center

Nay, Fred W.; Malm, Loren D.; Malone, Bobby G.; Oliver, Brad E.; Saunders, Nancy G.; Thompson, Jay C., Jr.

College faculty can avoid investing valuable time and resources in inappropriate technologies by staying in step with technological progress. A "future proof" approach to technology recognizes and welcomes small failures, considering them part of the ongoing process of absorbing technology into the learning process. Future proofing attempts to…

Reference and Reference Failures. Technical Report No. 398.

ERIC Educational Resources Information Center

Goodman, Bradley A.

In order to build robust natural language processing systems that can detect and recover from miscommunication, the investigation of how people communicate and how they recover from problems in communication described in this artificial intelligence report focused on reference problems which a listener may have in determining what or whom a…

Moral Disengagement in Science and Business Students: An Exploratory Study

ERIC Educational Resources Information Center

Cory, Suzanne N.

2015-01-01

Cases of unethical business practices and technical failures have been extensively reported. It seems that actions are often taken by individuals with little apparent concern for those affected by their negative outcomes, which can be described as moral disengagement. This study investigates levels of moral disengagement demonstrated by business…

Directory of aerospace safety specialized information sources

NASA Technical Reports Server (NTRS)

Fullerton, E. A.; Rubens, L. S.; Mandel, G.; Mckenna, P. J.

1974-01-01

Directory aids safety specialists in locating information sources and individual experts in engineering-related fields. Lists 170 organizations and approximately 300 individuals who can provide safety-related technical information in form of documentation, data, and consulting expertise. Information on hazard and failure cause identification, accident analysis, and materials characteristics are covered.

Transcatheter Arterial Embolization for Hepatic Arterial Injury Related to Percutaneous Transhepatic Portal Intervention

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shimohira, Masashi, E-mail: mshimohira@gmail.com; Hashizume, Takuya; Sasaki, Shigeru

PurposeTo assess the usefulness of transcatheter arterial embolization (TAE) for the hepatic arterial injury related to percutaneous transhepatic portal intervention (PTPI).Materials and MethodsFifty-four patients, 32 males and 22 females with a median age of 68 years (range 43–82 years), underwent PTPI. The procedures consisted of 33 percutaneous transhepatic portal vein embolizations, 19 percutaneous transhepatic variceal embolizations, and 2 percutaneous transhepatic portal venous stent placements. Two patients with gastric varices underwent percutaneous transhepatic variceal embolization twice because of recurrence. Therefore, the total number of procedures was 56. Among them, hepatic arterial injury occurred in 6 PTPIs in 5 patients, and TAE was performed.more » We assessed technical success, complications related to TAE, and clinical outcome. Technical success was defined as the disappearance of findings due to hepatic arterial injury on digital subtraction angiography.ResultsAs hepatic arterial injuries, 4 extravasations and 2 arterioportal shunts developed. All TAEs were performed successfully. The technical success rate was 100 %. Complication of TAE occurred in 5 of 6 TAEs; 3 were focal liver infarction, not requiring further treatment, and 2 were biloma that required percutaneous drainage. Five TAEs in 4 patients were performed immediately after the PTPI, and these 4 patients were alive. However, one TAE was performed 10 h later, and the patient died due to multiple organ failure 2 months later although TAE was successful.ConclusionTAE is a useful treatment for hepatic arterial injury related to PTPI. However, it should be performed at an early stage.« less

An Efficient Implementation of Fixed Failure-Rate Ratio Test for GNSS Ambiguity Resolution.

PubMed

Hou, Yanqing; Verhagen, Sandra; Wu, Jie

2016-06-23

Ambiguity Resolution (AR) plays a vital role in precise GNSS positioning. Correctly-fixed integer ambiguities can significantly improve the positioning solution, while incorrectly-fixed integer ambiguities can bring large positioning errors and, therefore, should be avoided. The ratio test is an extensively used test to validate the fixed integer ambiguities. To choose proper critical values of the ratio test, the Fixed Failure-rate Ratio Test (FFRT) has been proposed, which generates critical values according to user-defined tolerable failure rates. This contribution provides easy-to-implement fitting functions to calculate the critical values. With a massive Monte Carlo simulation, the functions for many different tolerable failure rates are provided, which enriches the choices of critical values for users. Moreover, the fitting functions for the fix rate are also provided, which for the first time allows users to evaluate the conditional success rate, i.e., the success rate once the integer candidates are accepted by FFRT. The superiority of FFRT over the traditional ratio test regarding controlling the failure rate and preventing unnecessary false alarms is shown by a simulation and a real data experiment. In the real data experiment with a baseline of 182.7 km, FFRT achieved much higher fix rates (up to 30% higher) and the same level of positioning accuracy from fixed solutions as compared to the traditional critical value.

Managing change: an overview.

PubMed

Lorenzi, N M; Riley, R T

2000-01-01

As increasingly powerful informatics systems are designed, developed, and implemented, they inevitably affect larger, more heterogeneous groups of people and more organizational areas. In turn, the major challenges to system success are often more behavioral than technical. Successfully introducing such systems into complex health care organizations requires an effective blend of good technical and good organizational skills. People who have low psychological ownership in a system and who vigorously resist its implementation can bring a "technically best" system to its knees. However, effective leadership can sharply reduce the behavioral resistance to change-including to new technologies-to achieve a more rapid and productive introduction of informatics technology. This paper looks at four major areas-why information system failures occur, the core theories supporting change management, the practical applications of change management, and the change management efforts in informatics.

Figures and First Years: Examining first-year Calculus I student ability to incorporate figures into technical reports

NASA Astrophysics Data System (ADS)

Antonacci, Nathan; Rogers, Michael; Pfaff, Thomas

This three-year study focused on first-year Calculus I students and their abilities to incorporate figures into technical reports. Students were handed guidelines as part of their Multidisciplinary Sustainability Education Module meant to aid them in crafting effective figures. Figure-specific questionnaires were added in the class to gain insight into the quantitative literacy skills students possessed both before starting their course and after its completion. Reviews of the figures in 78 technical reports written by 106 students showed repeated failure to refer to figures in discussion sections and use them in evidence-based arguments. Analysis of quantitative literacy skills revealed that the students could both read and interpret figures, suggesting that issues with literacy were not the main contributor to the sub-par graphs.

STS-114 Engine Cut-off Sensor Anomaly Technical Consultation Report

NASA Technical Reports Server (NTRS)

Wilson, Timmy R.; Kichak, Robert A.; Ungar, Eugene K.; Cherney, Robert; Rickman, Steve L.

2009-01-01

The NESC consultation team participated in real-time troubleshooting of the Main Propulsion System (MPS) Engine Cutoff (ECO) sensor system failures during STS-114 launch countdown. The team assisted with External Tank (ET) thermal and ECO Point Sensor Box (PSB) circuit analyses, and made real-time inputs to the Space Shuttle Program (SSP) problem resolution teams. Several long-term recommendations resulted. One recommendation was to conduct cryogenic tests of the ECO sensors to validate, or disprove, the theory that variations in circuit impedance due to cryogenic effects on swaged connections within the sensor were the root cause of STS-114 failures.

Nondestructive evaluation tools and experimental studies for monitoring the health of space propulsion systems

NASA Technical Reports Server (NTRS)

Generazio, Edward R.

1991-01-01

An overview is given of background and information on space propulsion systems on both the programmatic and technical levels. Feasibility experimental studies indicate that nondestructive evaluation tools such as ultrasonic, eddy current and x-ray may be successfully used to monitor the life limiting failure mechanisms of space propulsion systems. Encouraging results were obtained for monitoring the life limiting failure mechanisms for three space propulsion systems; the degradation of tungsten arcjet and magnetoplasmadynamic electrodes; presence and thickness of spallable electrically conducting molybdenum films in ion thrusters; and the degradation of the catalyst in hydrazine thrusters.

Overview of Threats and Failure Models for Safety-Relevant Computer-Based Systems

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo

2015-01-01

This document presents a high-level overview of the threats to safety-relevant computer-based systems, including (1) a description of the introduction and activation of physical and logical faults; (2) the propagation of their effects; and (3) function-level and component-level error and failure mode models. These models can be used in the definition of fault hypotheses (i.e., assumptions) for threat-risk mitigation strategies. This document is a contribution to a guide currently under development that is intended to provide a general technical foundation for designers and evaluators of safety-relevant systems.

Advanced Gas Turbine (AGT) power-train system development

NASA Technical Reports Server (NTRS)

Helms, H. E.; Johnson, R. A.; Gibson, R. K.

1982-01-01

Technical work on the design and component testing of a 74.5 kW (100 hp) advanced automotive gas turbine is described. Selected component ceramic component design, and procurement were tested. Compressor tests of a modified rotor showed high speed performance improvement over previous rotor designs; efficiency improved by 2.5%, corrected flow by 4.6%, and pressure ratio by 11.6% at 100% speed. The aerodynamic design is completed for both the gasifier and power turbines. Ceramic (silicon carbide) gasifier rotors were spin tested to failure. Improving strengths is indicated by burst speeds and the group of five rotors failed at speeds between 104% and 116% of engine rated speed. The emission results from combustor testing showed NOx levels to be nearly one order of magnitude lower than with previous designs. A one piece ceramic exhaust duct/regenerator seal platform is designed with acceptable low stress levels.

Alternative Treatment for Bleeding Peristomal Varices: Percutaneous Parastomal Embolization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pabon-Ramos, Waleska M., E-mail: waly.pr@duke.edu; Niemeyer, Matthew M.; Dasika, Narasimham L., E-mail: narasimh@med.umich.edu

2013-10-15

Purpose: To describe how peristomal varices can be successfully embolized via a percutaneous parastomal approach. Methods: The medical records of patients who underwent this procedure between December 1, 2000, and May 31, 2008, were retrospectively reviewed. Procedural details were recorded. Median fluoroscopy time and bleeding-free interval were calculated. Results: Seven patients underwent eight parastomal embolizations. The technical success rate was 88 % (one failure). All embolizations were performed with coils combined with a sclerosant, another embolizing agent, or both. Of the seven successful parastomal embolizations, there were three cases of recurrent bleeding; the median time to rebleeding was 45 daysmore » (range 26-313 days). The remaining four patients did not develop recurrent bleeding during the follow-up period; their median bleeding-free interval was 131 days (range 40-659 days). Conclusion: This case review demonstrated that percutaneous parastomal embolization is a feasible technique to treat bleeding peristomal varices.« less

The feasibility of remote-controlled assistance as a search tool for patient education.

PubMed

Lin, I K; Bray, B E; Smith, J A; Lange, L L

2001-01-01

Patients often desire more information about their conditions than they receive during a physician office visit. To address the patient's information needs, a touchscreen information kiosk was implemented. Results from the first prototype identified interface, security, and technical issues. Misspelling of search terms was identified as the most observable cause of search failure. An experimental remote control assistance feature was added in the second prototype. The feature allowed a medical librarian to provide real-time remote help during searches by taking control of the patient's computer. Remote assistance improved patient satisfaction, increased ease of use, and raised document retrieval rate (86.7% vs. 56.7%). Both patients and librarians found the application useful. Reasons included its convenience and flexibility, opportunity for direct patient contact, ability to teach through direct demonstration, and complementing the librarian's role as an information gateway. The project demonstrated the feasibility of applying remote control technology to patient education.

Microcircuit Device Reliability. Digital Failure Rate Data

DTIC Science & Technology

1981-01-01

Center Staff I IT Research Institute Under Contract to: Rome Air Development Center Griffiss AFB, NY 13441 fortes Ordering No. MDR- 17 biKi frbi...r ■■ ■—■ — SECURITY CLASSIFICATION Or THIS PAGE (Whin Dmlm Enlti»<l) REPORT DOCUMENTATION PAGE «EPO«TNUMBER MDR- 17 4. TITLE (md...MDR- 17 presents com- parisons between actual field experienced failure rates and MIL-HDBK-217C, Notice 1, predicted failure rates. The use of

Infraclavicular versus axillary nerve catheters: A retrospective comparison of early catheter failure rate.

PubMed

Quast, Michaela B; Sviggum, Hans P; Hanson, Andrew C; Stoike, David E; Martin, David P; Niesen, Adam D

2018-05-01

Continuous brachial plexus catheters are often used to decrease pain following elbow surgery. This investigation aimed to assess the rate of early failure of infraclavicular (IC) and axillary (AX) nerve catheters following elbow surgery. Retrospective study. Postoperative recovery unit and inpatient hospital floor. 328 patients who received IC or AX nerve catheters and underwent elbow surgery were identified by retrospective query of our institution's database. Data collected included unplanned catheter dislodgement, catheter replacement rate, postoperative pain scores, and opioid administration on postoperative day 1. Catheter failure was defined as unplanned dislodging within 24 h of placement or requirement for catheter replacement and evaluated using a covariate adjusted model. 119 IC catheters and 209 AX catheters were evaluated. There were 8 (6.7%) failed IC catheters versus 13 (6.2%) failed AX catheters. After adjusting for age, BMI, and gender there was no difference in catheter failure rate between IC and AX nerve catheters (p = 0.449). These results suggest that IC and AX nerve catheters do not differ in the rate of early catheter failure, despite differences in anatomic location and catheter placement techniques. Both techniques provided effective postoperative analgesia with median pain scores < 3/10 for patients following elbow surgery. Reasons other than rate of early catheter failure should dictate which approach is performed. Copyright © 2018. Published by Elsevier Inc.

External Tank Program Legacy of Success

NASA Technical Reports Server (NTRS)

Welzyn, Ken; Pilet, Jeff

2010-01-01

I.Goal: a) Extensive TPS damage caused by extreme hail storm. b) Repair plan required to restore TPS to minimize program manifest impacts. II. Challenges: a) Skeptical technical community - Concerned about interactions of damage with known/unknown failure modes. b) Schedule pressure to accommodate ISS program- Next tank still at MAF c)Limited ET resources. III. How d We Do It?: a) Developed unique engineering requirements and tooling to minimize repairs. b) Performed large amount of performance testing to demonstrate understanding of repairs and residual conditions. c) Effectively communicated results to technical community and management to instill confidence in expected performance.

National trends in rates of death and hospital admissions related to acute myocardial infarction, heart failure and stroke, 1994–2004

PubMed Central

Tu, Jack V.; Nardi, Lorelei; Fang, Jiming; Liu, Juan; Khalid, Laila; Johansen, Helen

2009-01-01

Background Rates of death from cardiovascular and cerebrovascular diseases have been steadily declining over the past few decades. Whether such declines are occurring to a similar degree for common disorders such as acute myocardial infarction, heart failure and stroke is uncertain. We examined recent national trends in mortality and rates of hospital admission for these 3 conditions. Methods We analyzed mortality data from Statistic Canada’s Canadian Mortality Database and data on hospital admissions from the Canadian Institute for Health Information’s Hospital Morbidity Database for the period 1994–2004. We determined age- and sex-standardized rates of death and hospital admissions per 100 000 population aged 20 years and over as well as in-hospital case-fatality rates. Results The overall age- and sex-standardized rate of death from cardiovascular disease in Canada declined 30.0%, from 360.6 per 100 000 in 1994 to 252.5 per 100 000 in 2004. During the same period, the rate fell 38.1% for acute myocardial infarction, 23.5% for heart failure and 28.2% for stroke, with improvements observed across most age and sex groups. The age- and sex-standardized rate of hospital admissions decreased 27.6% for stroke and 27.2% for heart failure. The rate for acute myocardial infarction fell only 9.2%. In contrast, the relative decline in the inhospital case-fatality rate was greatest for acute myocardial infarction (33.1%; p < 0.001). Much smaller relative improvements in case-fatality rates were noted for heart failure (8.1%) and stroke (8.9%). Interpretation The rates of death and hospital admissions for acute myocardial infarction, heart failure and stroke in Canada changed at different rates over the 10-year study period. Awareness of these trends may guide future efforts for health promotion and health care planning and help to determine priorities for research and treatment. PMID:19546444

Movement evaluation of front crawl swimming: Technical skill versus aesthetic quality

PubMed Central

2017-01-01

The study aim was to compare expert with non-expert swimmers’ rating of the aesthetic and technical qualities of front crawl in video-taped recordings of swimmers with low, middle, and high level proficiency. The results suggest that: i) observers’ experience affects their judgment: only the expert observers correctly rated the swimmers’ proficiency level; ii) evaluation of movement (technical and aesthetic scores) is correlated with the level of skill as expressed in the kinematics of the observed action (swimming speed, stroke frequency, and stroke length); iii) expert and non-expert observers use different strategies to rate the aesthetic and technical qualities of movement: equating the technical skill with the aesthetic quality is a general rule non-expert observers follow in the evaluation of human movement. PMID:28886063

Using Generic Data to Establish Dormancy Failure Rates

NASA Technical Reports Server (NTRS)

Reistle, Bruce

2014-01-01

Many hardware items are dormant prior to being operated. The dormant period might be especially long, for example during missions to the moon or Mars. In missions with long dormant periods the risk incurred during dormancy can exceed the active risk contribution. Probabilistic Risk Assessments (PRAs) need to account for the dormant risk contribution as well as the active contribution. A typical method for calculating a dormant failure rate is to multiply the active failure rate by a constant, the dormancy factor. For example, some practitioners use a heuristic and divide the active failure rate by 30 to obtain an estimate of the dormant failure rate. To obtain a more empirical estimate of the dormancy factor, this paper uses the recently updated database NPRD-2011 [1] to arrive at a set of distributions for the dormancy factor. The resulting dormancy factor distributions are significantly different depending on whether the item is electrical, mechanical, or electro-mechanical. Additionally, this paper will show that using a heuristic constant fails to capture the uncertainty of the possible dormancy factors.

Estimation of Energy Efficiency of Means of Transport According to the Results of Technical Diagnostics

NASA Astrophysics Data System (ADS)

Shalkov, Anton; Mamaeva, Mariya

2017-11-01

The article considers the questions of application of nondestructive methods control of reducers of conveyor belts as a means of transport. Particular attention is paid to such types of diagnostics of technical condition as thermal control and analysis of the state of lubricants. The urgency of carrying out types of nondestructive testing presented in the article is determined by the increase of energy efficiency of transport systems of coal and mining enterprises, in particular, reducers of belt conveyors. Periodic in-depth spectral-emission diagnostics and monitoring of a temperature mode of operation oil in the operation of the control equipment and its technical condition and prevent the MTBF allows the monitoring of the actual technical condition of the gearbox of a belt conveyor. In turn, the thermal imaging diagnostics reveals defects at the earliest stage of their formation and development, which allows planning the volumes and terms of equipment repair. Presents diagnostics of the technical condition will allow monitoring in time the technical condition of the equipment and avoiding its premature failure. Thereby it will increase the energy efficiency of both the transport system and the enterprise as a whole, and also avoid unreasonable increases in operating and maintenance costs.

Accounting for Epistemic Uncertainty in Mission Supportability Assessment: A Necessary Step in Understanding Risk and Logistics Requirements

NASA Technical Reports Server (NTRS)

Owens, Andrew; De Weck, Olivier L.; Stromgren, Chel; Goodliff, Kandyce; Cirillo, William

2017-01-01

Future crewed missions to Mars present a maintenance logistics challenge that is unprecedented in human spaceflight. Mission endurance – defined as the time between resupply opportunities – will be significantly longer than previous missions, and therefore logistics planning horizons are longer and the impact of uncertainty is magnified. Maintenance logistics forecasting typically assumes that component failure rates are deterministically known and uses them to represent aleatory uncertainty, or uncertainty that is inherent to the process being examined. However, failure rates cannot be directly measured; rather, they are estimated based on similarity to other components or statistical analysis of observed failures. As a result, epistemic uncertainty – that is, uncertainty in knowledge of the process – exists in failure rate estimates that must be accounted for. Analyses that neglect epistemic uncertainty tend to significantly underestimate risk. Epistemic uncertainty can be reduced via operational experience; for example, the International Space Station (ISS) failure rate estimates are refined using a Bayesian update process. However, design changes may re-introduce epistemic uncertainty. Thus, there is a tradeoff between changing a design to reduce failure rates and operating a fixed design to reduce uncertainty. This paper examines the impact of epistemic uncertainty on maintenance logistics requirements for future Mars missions, using data from the ISS Environmental Control and Life Support System (ECLS) as a baseline for a case study. Sensitivity analyses are performed to investigate the impact of variations in failure rate estimates and epistemic uncertainty on spares mass. The results of these analyses and their implications for future system design and mission planning are discussed.

Application of failure mode and effect analysis in an assisted reproduction technology laboratory.

PubMed

Intra, Giulia; Alteri, Alessandra; Corti, Laura; Rabellotti, Elisa; Papaleo, Enrico; Restelli, Liliana; Biondo, Stefania; Garancini, Maria Paola; Candiani, Massimo; Viganò, Paola

2016-08-01

Assisted reproduction technology laboratories have a very high degree of complexity. Mismatches of gametes or embryos can occur, with catastrophic consequences for patients. To minimize the risk of error, a multi-institutional working group applied failure mode and effects analysis (FMEA) to each critical activity/step as a method of risk assessment. This analysis led to the identification of the potential failure modes, together with their causes and effects, using the risk priority number (RPN) scoring system. In total, 11 individual steps and 68 different potential failure modes were identified. The highest ranked failure modes, with an RPN score of 25, encompassed 17 failures and pertained to "patient mismatch" and "biological sample mismatch". The maximum reduction in risk, with RPN reduced from 25 to 5, was mostly related to the introduction of witnessing. The critical failure modes in sample processing were improved by 50% in the RPN by focusing on staff training. Three indicators of FMEA success, based on technical skill, competence and traceability, have been evaluated after FMEA implementation. Witnessing by a second human operator should be introduced in the laboratory to avoid sample mix-ups. These findings confirm that FMEA can effectively reduce errors in assisted reproduction technology laboratories. Copyright © 2016 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Improving the Estimates of International Space Station (ISS) Induced K-Factor Failure Rates for On-Orbit Replacement Unit (ORU) Supportability Analyses

NASA Technical Reports Server (NTRS)

Anderson, Leif F.; Harrington, Sean P.; Omeke, Ojei, II; Schwaab, Douglas G.

2009-01-01

This is a case study on revised estimates of induced failure for International Space Station (ISS) on-orbit replacement units (ORUs). We devise a heuristic to leverage operational experience data by aggregating ORU, associated function (vehicle sub -system), and vehicle effective' k-factors using actual failure experience. With this input, we determine a significant failure threshold and minimize the difference between the actual and predicted failure rates. We conclude with a discussion on both qualitative and quantitative improvements the heuristic methods and potential benefits to ISS supportability engineering analysis.

Technical aspects of the Space Telescope Imaging Spectrograph Repair (STIS-R)

NASA Astrophysics Data System (ADS)

Rinehart, S. A.; Domber, J.; Faulkner, T.; Gull, T.; Kimble, R.; Klappenberger, M.; Leckrone, D.; Niedner, M.; Proffitt, C.; Smith, H.; Woodgate, B.

2008-07-01

In August 2004, the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) ceased operation due to a failure of the 5V mechanism power converter in the Side 2 Low Voltage Power Supply (LVPS2). The failure precluded movement of any STIS mechanism and, because of the earlier (2001) loss of the Side 1 electronics chain, left the instrument shuttered and in safe mode after 7.5 years of science operations. A team was assembled to analyze the fault and to determine if STIS repair (STIS-R) was feasible. The team conclusively pinpointed the Side 2 failure to the 5V mechanism converter, and began studying EVA techniques for opening STIS during Servicing Mission 4 (SM4) to replace the failed LVPS2 board. The restoration of STIS functionality via surgical repair by astronauts has by now reached a mature and final design state, and will, along with a similar repair procedure for the Advanced Camera for Surveys (ACS), represent a first for Hubble servicing. STIS-R will restore full scientific functionality of the spectrograph on Side 2, while Side 1 will remain inoperative. Because of the high degree of complementarity between STIS and the new Cosmic Origins Spectrograph (COS, to be installed during SM4)), successful repair of the older spectrograph is an important scientific objective. In this presentation, we focus on the technical aspects associated with STIS-R.

Understanding and Resolving Failures in Human-Robot Interaction: Literature Review and Model Development

PubMed Central

Honig, Shanee; Oron-Gilad, Tal

2018-01-01

While substantial effort has been invested in making robots more reliable, experience demonstrates that robots operating in unstructured environments are often challenged by frequent failures. Despite this, robots have not yet reached a level of design that allows effective management of faulty or unexpected behavior by untrained users. To understand why this may be the case, an in-depth literature review was done to explore when people perceive and resolve robot failures, how robots communicate failure, how failures influence people's perceptions and feelings toward robots, and how these effects can be mitigated. Fifty-two studies were identified relating to communicating failures and their causes, the influence of failures on human-robot interaction (HRI), and mitigating failures. Since little research has been done on these topics within the HRI community, insights from the fields of human computer interaction (HCI), human factors engineering, cognitive engineering and experimental psychology are presented and discussed. Based on the literature, we developed a model of information processing for robotic failures (Robot Failure Human Information Processing, RF-HIP), that guides the discussion of our findings. The model describes the way people perceive, process, and act on failures in human robot interaction. The model includes three main parts: (1) communicating failures, (2) perception and comprehension of failures, and (3) solving failures. Each part contains several stages, all influenced by contextual considerations and mitigation strategies. Several gaps in the literature have become evident as a result of this evaluation. More focus has been given to technical failures than interaction failures. Few studies focused on human errors, on communicating failures, or the cognitive, psychological, and social determinants that impact the design of mitigation strategies. By providing the stages of human information processing, RF-HIP can be used as a tool to promote the development of user-centered failure-handling strategies for HRIs.

Predicting Quarantine Failure Rates

PubMed Central

2004-01-01

Preemptive quarantine through contact-tracing effectively controls emerging infectious diseases. Occasionally this quarantine fails, however, and infected persons are released. The probability of quarantine failure is typically estimated from disease-specific data. Here a simple, exact estimate of the failure rate is derived that does not depend on disease-specific parameters. This estimate is universally applicable to all infectious diseases. PMID:15109418

High rate of virological failure and low rate of switching to second-line treatment among adolescents and adults living with HIV on first-line ART in Myanmar, 2005-2015

PubMed Central

Harries, Anthony D.; Kumar, Ajay M. V.; Oo, Myo Minn; Kyaw, Khine Wut Yee; Win, Than; Aung, Thet Ko; Min, Aung Chan; Oo, Htun Nyunt

2017-01-01

Background The number of people living with HIV on antiretroviral treatment (ART) in Myanmar has been increasing rapidly in recent years. This study aimed to estimate rates of virological failure on first-line ART and switching to second-line ART due to treatment failure at the Integrated HIV Care program (IHC). Methods Routinely collected data of all adolescent and adult patients living with HIV who were initiated on first-line ART at IHC between 2005 and 2015 were retrospectively analyzed. The cumulative hazard of virological failure on first-line ART and switching to second-line ART were estimated. Crude and adjusted hazard ratios were calculated using the Cox regression model to identify risk factors associated with the two outcomes. Results Of 23,248 adults and adolescents, 7,888 (34%) were tested for HIV viral load. The incidence rate of virological failure among those tested was 3.2 per 100 person-years follow-up and the rate of switching to second-line ART among all patients was 1.4 per 100 person-years follow-up. Factors associated with virological failure included: being adolescent; being lost to follow-up at least once; having WHO stage 3 and 4 at ART initiation; and having taken first-line ART elsewhere before coming to IHC. Of the 1032 patients who met virological failure criteria, 762 (74%) switched to second-line ART. Conclusions We found high rates of virological failure among one third of patients in the cohort who were tested for viral load. Of those failing virologically on first-line ART, about one quarter were not switched to second-line ART. Routine viral load monitoring, especially for those identified as having a higher risk of treatment failure, should be considered in this setting to detect all patients failing on first-line ART. Strategies also need to be put in place to prevent treatment failure and to treat more of those patients who are actually failing. PMID:28182786

Is rhythm-control superior to rate-control in patients with atrial fibrillation and diastolic heart failure?

PubMed

Kong, Melissa H; Shaw, Linda K; O'Connor, Christopher; Califf, Robert M; Blazing, Michael A; Al-Khatib, Sana M

2010-07-01

Although no clinical trial data exist on the optimal management of atrial fibrillation (AF) in patients with diastolic heart failure, it has been hypothesized that rhythm-control is more advantageous than rate-control due to the dependence of these patients' left ventricular filling on atrial contraction. We aimed to determine whether patients with AF and heart failure with preserved ejection fraction (EF) survive longer with rhythm versus rate-control strategy. The Duke Cardiovascular Disease Database was queried to identify patients with EF > 50%, heart failure symptoms and AF between January 1,1995 and June 30, 2005. We compared baseline characteristics and survival of patients managed with rate- versus rhythm-control strategies. Using a 60-day landmark view, Kaplan-Meier curves were generated and results were adjusted for baseline differences using Cox proportional hazards modeling. Three hundred eighty-two patients met the inclusion criteria (285 treated with rate-control and 97 treated with rhythm-control). The 1-, 3-, and 5-year survival rates were 93.2%, 69.3%, and 56.8%, respectively in rate-controlled patients and 94.8%, 78.0%, and 59.9%, respectively in rhythm-controlled patients (P > 0.10). After adjustments for baseline differences, no significant difference in mortality was detected (hazard ratio for rhythm-control vs rate-control = 0.696, 95% CI 0.453-1.07, P = 0.098). Based on our observational data, rhythm-control seems to offer no survival advantage over rate-control in patients with heart failure and preserved EF. Randomized clinical trials are needed to verify these findings and examine the effect of each strategy on stroke risk, heart failure decompensation, and quality of life.

Limits on rock strength under high confinement

NASA Astrophysics Data System (ADS)

Renshaw, Carl E.; Schulson, Erland M.

2007-06-01

Understanding of deep earthquake source mechanisms requires knowledge of failure processes active under high confinement. Under low confinement the compressive strength of rock is well known to be limited by frictional sliding along stress-concentrating flaws. Under higher confinement strength is usually assumed limited by power-law creep associated with the movement of dislocations. In a review of existing experimental data, we find that when the confinement is high enough to suppress frictional sliding, rock strength increases as a power-law function only up to a critical normalized strain rate. Within the regime where frictional sliding is suppressed and the normalized strain rate is below the critical rate, both globally distributed ductile flow and localized brittle-like failure are observed. When frictional sliding is suppressed and the normalized strain rate is above the critical rate, failure is always localized in a brittle-like manner at a stress that is independent of the degree of confinement. Within the high-confinement, high-strain rate regime, the similarity in normalized failure strengths across a variety of rock types and minerals precludes both transformational faulting and dehydration embrittlement as strength-limiting mechanisms. The magnitude of the normalized failure strength corresponding to the transition to the high-confinement, high-strain rate regime and the observed weak dependence of failure strength on strain rate within this regime are consistent with a localized Peierls-type strength-limiting mechanism. At the highest strain rates the normalized strengths approach the theoretical limit for crystalline materials. Near-theoretical strengths have previously been observed only in nano- and micro-scale regions of materials that are effectively defect-free. Results are summarized in a new deformation mechanism map revealing that when confinement and strain rate are sufficient, strengths approaching the theoretical limit can be achieved in cm-scale sized samples of rocks rich in defects. Thus, non-frictional failure processes must be considered when interpreting rock deformation data collected under high confinement and low temperature. Further, even at higher temperatures the load-bearing ability of crustal rocks under high confinement may not be limited by a frictional process under typical geologic strain rates.

Relative importance of physical and economic factors in Appalachian coalbed gas assessment

USGS Publications Warehouse

Attanasi, E.D.

1998-01-01

In the 1995 National Assessment of Oil and Gas Resources prepared by the U.S. Geological Survey, only 20% of the assessed technically recoverable Appalachian Province coalbed gas resources were economic. Physical and economic variables are examined to explain the disparity between economic and technically recoverable coalbed gas. The Anticline and Syncline plays of the Northern Appalachian Basin, which account for 77% of the assessed technically recoverable coalbed gas, are not economic. Analysis shows marginal reductions in costs or rate of return will not turn these plays into commercial successes. Physical parameters that determine ultimate well recoverability and the rate of gas recovery are primary reasons the Northern Appalachian Basin plays are non-commercial. If the application of new well stimulation technology could offset slow gas desorption rates, Appalachian Province economic gas could increase to more then 70% of the technically recoverable gas. Similarly, if operators are able to develop strategies to selectively drill plays by avoiding dry holes and non-commercial occurrences, the economic fraction of technically recoverable gas could increase to over half.In the 1995 National Assessment of Oil and Gas Resources prepared by the U.S. Geological Survey, only 20% of the assessed technically recoverable Appalachian Province coalbed gas resources were economic. Physical and economic variables are examined to explain the disparity between economic and technically recoverable coalbed gas. The Anticline and Syncline plays of the Northern Appalachian Basin, which account for 77% of the assessed technically recoverable coalbed gas, are not economic. Analysis shows marginal reductions in costs or rate of return will not turn these plays into commercial successes. Physical parameters that determine ultimate well recoverability and the rate of gas recovery are primary reasons the Northern Appalachian Basin plays are non-commercial. If the application of new well stimulation technology could offset slow gas desorption rates, Appalachian Province economic gas could increase to more then 70% of the technically recoverable gas. Similarly, if operators are able to develop strategies to selectively drill plays by avoiding dry holes and non-commercial occurrences, the economic fraction of technically recoverable gas could increase to over half.

On a Stochastic Failure Model under Random Shocks

NASA Astrophysics Data System (ADS)

Cha, Ji Hwan

2013-02-01

In most conventional settings, the events caused by an external shock are initiated at the moments of its occurrence. In this paper, we study a new classes of shock model, where each shock from a nonhomogeneous Poisson processes can trigger a failure of a system not immediately, as in classical extreme shock models, but with delay of some random time. We derive the corresponding survival and failure rate functions. Furthermore, we study the limiting behaviour of the failure rate function where it is applicable.

Relation between lowered colloid osmotic pressure, respiratory failure, and death.

PubMed

Tonnesen, A S; Gabel, J C; McLeavey, C A

1977-01-01

Plasma colloid osmotic pressure was measured each day in 84 intensive care unit patients. Probit analysis demonstrated a direct relationship between colloid osmotic pressure (COP) and survival. The COP associated with a 50% survival rate was 15.0 torr. COP was higher in survivors than in nonsurvivors without respiratory failure and in patients who recovered from respiratory failure. We conclude that lowered COP is associated with an elevated mortality rate. However, the relationship to death is not explained by the relationship to respiratory failure.

Failure analysis and modeling of a VAXcluster system

NASA Technical Reports Server (NTRS)

Tang, Dong; Iyer, Ravishankar K.; Subramani, Sujatha S.

1990-01-01

This paper discusses the results of a measurement-based analysis of real error data collected from a DEC VAXcluster multicomputer system. In addition to evaluating basic system dependability characteristics such as error and failure distributions and hazard rates for both individual machines and for the VAXcluster, reward models were developed to analyze the impact of failures on the system as a whole. The results show that more than 46 percent of all failures were due to errors in shared resources. This is despite the fact that these errors have a recovery probability greater than 0.99. The hazard rate calculations show that not only errors, but also failures occur in bursts. Approximately 40 percent of all failures occur in bursts and involved multiple machines. This result indicates that correlated failures are significant. Analysis of rewards shows that software errors have the lowest reward (0.05 vs 0.74 for disk errors). The expected reward rate (reliability measure) of the VAXcluster drops to 0.5 in 18 hours for the 7-out-of-7 model and in 80 days for the 3-out-of-7 model.

Historic and Current Launcher Success Rates

NASA Technical Reports Server (NTRS)

Rust, Randy

2002-01-01

This presentation reviews historic and current space launcher success rates from all nations with a mature launcher industry. Data from the 1950's through present day is reviewed for possible trends such as when in the launch timeline a failure occurred, which stages had the highest failure rate, overall launcher reliability, a decade by decade look at launcher reliability, when in a launchers history did failures occur, and the reliability of United States human-rated launchers. This information is useful in determining where launcher reliability can be improved and where additional measures for crew survival (i.e., Crew Escape systems) will have the greatest emphasis

[Reduction of rehospitalisation on elderly heart failure patients: A retrospective cohort VISage network].

PubMed

Labranche, D; Mestre-Fernandes, C; Delahaye, F; Sanchez, S

2016-11-01

Heart failure was a public health problem for one million of French patients. Patients are particularly concerned in rehospitalisation for this chronic pathology. A specific healthcare network was created to take care of patients with heart failure directly at home. This healthcare network (named VISage) brings a specific and adapted monitoring in heart failure. The main of this study was to evaluate the impact of healthcare network in rehospitalisation rate for heart failure of patients. We conducted a retrospective cohort study with patients' hospital files of the CH Vienne. Patients who were included in our healthcare network (VISage) were screened. Primary endpoint was 30days, 6 months, and 1year rehospitalisation rate for heart failure before and after using healthcare network. One hundred and four patients with comorbidities were included between February 2009 and November 2015. A significant reduction of rehospitalisation rate for heart failure was observed before and after network: 0.65 (±0.52) vs. 0.17 (±0.43) 30days, 1.17 (±0.74) vs. 0.42 (±0.71) at 6 months and 1.35 (±0.95) vs. 0.47 (±0.74) at 1 year (P<0.0001). Results were significant for global rehospitalisation rate too. No significant differences were shown on hospital length of stay. Coordinated healthcare by a specific network at home for elderly is benefic for the rehospitalisation rate. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Examination of the relationship between project management critical success factors and project success of oil and gas drilling projects

NASA Astrophysics Data System (ADS)

Alagba, Tonye J.

Oil and gas drilling projects are the primary means by which oil companies recover large volumes of commercially available hydrocarbons from deep reservoirs. These types of projects are complex in nature, involving management of multiple stakeholder interfaces, multidisciplinary personnel, complex contractor relationships, and turbulent environmental and market conditions, necessitating the application of proven project management best practices and critical success factors (CSFs) to achieve success. Although there is some practitioner oriented literature on project management CSFs for drilling projects, none of these is based on empirical evidence, from research. In addition, the literature has reported alarming rates of oil and gas drilling project failure, which is attributable not to technical factors, but to failure of project management. The aim of this quantitative correlational study therefore, was to discover an empirically verified list of project management CSFs, which consistent application leads to successful implementation of oil and gas drilling projects. The study collected survey data online, from a random sample of 127 oil and gas drilling personnel who were members of LinkedIn's online community "Drilling Supervisors, Managers, and Engineers". The results of the study indicated that 10 project management factors are individually related to project success of oil and gas drilling projects. These 10 CSFs are namely; Project mission, Top management support, Project schedule/plan, Client consultation, Personnel, Technical tasks, Client acceptance, Monitoring and feedback, Communication, and Troubleshooting. In addition, the study found that the relationships between the 10 CSFs and drilling project success is unaffected by participant and project demographics---role of project personnel, and project location. The significance of these findings are both practical, and theoretical. Practically, application of an empirically verified CSFs list to oil and gas drilling projects could help oil companies improve the performance of future drilling projects. Theoretically, the study's findings may help to bridge a gap in the project management CSFs literature, and add to the general project management body of knowledge.

Local Failure in Resected N1 Lung Cancer: Implications for Adjuvant Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Higgins, Kristin A., E-mail: kristin.higgins@duke.edu; Chino, Junzo P.; Berry, Mark

2012-06-01

Purpose: To evaluate actuarial rates of local failure in patients with pathologic N1 non-small-cell lung cancer and to identify clinical and pathologic factors associated with an increased risk of local failure after resection. Methods and Materials: All patients who underwent surgery for non-small-cell lung cancer with pathologically confirmed N1 disease at Duke University Medical Center from 1995-2008 were identified. Patients receiving any preoperative therapy or postoperative radiotherapy or with positive surgical margins were excluded. Local failure was defined as disease recurrence within the ipsilateral hilum, mediastinum, or bronchial stump/staple line. Actuarial rates of local failure were calculated with the Kaplan-Meiermore » method. A Cox multivariate analysis was used to identify factors independently associated with a higher risk of local recurrence. Results: Among 1,559 patients who underwent surgery during the time interval, 198 met the inclusion criteria. Of these patients, 50 (25%) received adjuvant chemotherapy. Actuarial (5-year) rates of local failure, distant failure, and overall survival were 40%, 55%, and 33%, respectively. On multivariate analysis, factors associated with an increased risk of local failure included a video-assisted thoracoscopic surgery approach (hazard ratio [HR], 2.5; p = 0.01), visceral pleural invasion (HR, 2.1; p = 0.04), and increasing number of positive N1 lymph nodes (HR, 1.3 per involved lymph node; p = 0.02). Chemotherapy was associated with a trend toward decreased risk of local failure that was not statistically significant (HR, 0.61; p = 0.2). Conclusions: Actuarial rates of local failure in pN1 disease are high. Further investigation of conformal postoperative radiotherapy may be warranted.« less

Molecular Dynamics Modeling of PPTA Crystals in Aramid Fibers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mercer, Brian Scott

2016-05-19

In this work, molecular dynamics modeling is used to study the mechanical properties of PPTA crystallites, which are the fundamental microstructural building blocks of polymer aramid bers such as Kevlar. Particular focus is given to constant strain rate axial loading simulations of PPTA crystallites, which is motivated by the rate-dependent mechanical properties observed in some experiments with aramid bers. In order to accommodate the covalent bond rupture that occurs in loading a crystallite to failure, the reactive bond order force eld ReaxFF is employed to conduct the simulations. Two major topics are addressed: The rst is the general behavior ofmore » PPTA crystallites under strain rate loading. Constant strain rate loading simulations of crystalline PPTA reveal that the crystal failure strain increases with increasing strain rate, while the modulus is not a ected by the strain rate. Increasing temperature lowers both the modulus and the failure strain. The simulations also identify the C N bond connecting the aromatic rings as weakest primary bond along the backbone of the PPTA chain. The e ect of chain-end defects on PPTA micromechanics is explored, and it is found that the presence of a chain-end defect transfers load to the adjacent chains in the hydrogen-bonded sheet in which the defect resides, but does not in uence the behavior of any other chains in the crystal. Chain-end defects are found to lower the strength of the crystal when clustered together, inducing bond failure via stress concentrations arising from the load transfer to bonds in adjacent chains near the defect site. The second topic addressed is the nature of primary and secondary bond failure in crystalline PPTA. Failure of both types of bonds is found to be stochastic in nature and driven by thermal uctuations of the bonds within the crystal. A model is proposed which uses reliability theory to model bonds under constant strain rate loading as components with time-dependent failure rate functions. The model is shown to work well for predicting the onset of primary backbone bond failure, as well as the onset of secondary bond failure via chain slippage for the case of isolated non-interacting chain-end defects.« less

Crowd-sourced assessment of technical skills: an opportunity for improvement in the assessment of laparoscopic surgical skills.

PubMed

Deal, Shanley B; Lendvay, Thomas S; Haque, Mohamad I; Brand, Timothy; Comstock, Bryan; Warren, Justin; Alseidi, Adnan

2016-02-01

Objective, unbiased assessment of surgical skills remains a challenge in surgical education. We sought to evaluate the feasibility and reliability of Crowd-Sourced Assessment of Technical Skills. Seven volunteer general surgery interns were given time for training and then testing, on laparoscopic peg transfer, precision cutting, and intracorporeal knot-tying. Six faculty experts (FEs) and 203 Amazon.com Mechanical Turk crowd workers (CWs) evaluated 21 deidentified video clips using the Global Objective Assessment of Laparoscopic Skills validated rating instrument. Within 19 hours and 15 minutes we received 662 eligible ratings from 203 CWs and 126 ratings from 6 FEs over 10 days. FE video ratings were of borderline internal consistency (Krippendorff's alpha = .55). FE ratings were highly correlated with CW ratings (Pearson's correlation coefficient = .78, P < .001). We propose the use of Crowd-Sourced Assessment of Technical Skills as a reliable, basic tool to standardize the evaluation of technical skills in general surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessment of the Accuracy and Cut-Failure Rates of Eye Bank-Cut Corneas for Use in Endothelial Keratoplasty: A Comparison of Outcomes Between 2010 and 2013.

PubMed

Katzman, Lee R; Hoover, Caroline K; Khalifa, Yousuf M; Jeng, Bennie H

2015-11-01

To evaluate the accuracy of eye bank-prepared precut donor corneas over time by comparing cut-failure rates and corneal thickness measurements in 2010 and 2013. A total of 2511 human corneas cut by a technician-operated mechanical microkeratome intended for endothelial keratoplasty were evaluated prospectively at one large eye bank facility in 2010 and in 2013. The endothelium was evaluated by slit lamp, and specular microscopy both before and after cutting was performed. Graft thickness as measured by pachymetry and/or optical coherence tomography was collected to assess the accuracy of the cut tissue. Cut-failure rates were compared between normal donor tissue and tissue with significant preexisting scarring. The combined cut-failure rate in 2010 and 2013 was 2.3% (23/1000) and 1.6% (24/1511), respectively (P = 0.23). The cut-failure rate among normal tissue in 2010 and 2013 was 2.0% (19/927) and 1.4% (19/1400), respectively (P = 0.24). The cut-failure rate among previously scarred tissue in 2010 and 2013 was 5.5% (4/73) and 4.5% (5/111), respectively (P = 0.74). The mean surgeon-requested graft thickness was 144.7 μm (range 100-150, SD 13.6) and 127.2 μm (range 75-150, SD 25.2) in 2010 and 2013, respectively (P < 0.0001). The mean deviation from target graft thickness was 21.3 μm (SD 16.3) and 13.6 μm (SD 12.5) in 2010 and 2013, respectively (P < 0.0001). From 2010 to 2013, the combined cut-failure rates trended toward improvement, while the accuracy of graft thickness improved. This study suggests that the accuracy and success rates of tissue preparation for endothelial keratoplasty improve with experience and volume.

A novel approach to assessing technical competence of colorectal surgery residents: the development and evaluation of the Colorectal Objective Structured Assessment of Technical Skill (COSATS).

PubMed

de Montbrun, Sandra L; Roberts, Patricia L; Lowry, Ann C; Ault, Glenn T; Burnstein, Marcus J; Cataldo, Peter A; Dozois, Eric J; Dunn, Gary D; Fleshman, James; Isenberg, Gerald A; Mahmoud, Najjia N; Reznick, Richard K; Satterthwaite, Lisa; Schoetz, David; Trudel, Judith L; Weiss, Eric G; Wexner, Steven D; MacRae, Helen

2013-12-01

To develop and evaluate an objective method of technical skills assessment for graduating subspecialists in colorectal (CR) surgery-the Colorectal Objective Structured Assessment of Technical Skill (COSATS). It may be reasonable for the public to assume that surgeons certified as competent have had their technical skills assessed. However, technical skill, despite being the hallmark of a surgeon, is not directly assessed at the time of certification by surgical boards. A procedure-based, multistation technical skills examination was developed to reflect a sample of the range of skills necessary for CR surgical practice. These consisted of bench, virtual reality, and cadaveric models. Reliability and construct validity were evaluated by comparing 10 graduating CR residents with 10 graduating general surgery (GS) residents from across North America. Expert CR surgeons, blinded to level of training, evaluated performance using a task-specific checklist and a global rating scale. The mean global rating score was used as the overall examination score and a passing score was set at "borderline competent for CR practice." The global rating scale demonstrated acceptable interstation reliability (0.69) for a homogeneous group of examinees. Both the overall checklist and global rating scores effectively discriminated between CR and GS residents (P < 0.01), with 27% of the variance attributed to level of training. Nine CR residents but only 3 GS residents were deemed competent. The Colorectal Objective Structured Assessment of Technical Skill effectively discriminated between CR and GS residents. With further validation, the Colorectal Objective Structured Assessment of Technical Skill could be incorporated into the colorectal board examination where it would be the first attempt of a surgical specialty to formally assess technical skill at the time of certification.

Health IT success and failure: recommendations from literature and an AMIA workshop.

PubMed

Kaplan, Bonnie; Harris-Salamone, Kimberly D

2009-01-01

With the United States joining other countries in national efforts to reap the many benefits that use of health information technology can bring for health care quality and savings, sobering reports recall the complexity and difficulties of implementing even smaller-scale systems. Despite best practice research that identified success factors for health information technology projects, a majority, in some sense, still fail. Similar problems plague a variety of different kinds of applications, and have done so for many years. Ten AMIA working groups sponsored a workshop at the AMIA Fall 2006 Symposium. It was entitled "Avoiding The F-Word: IT Project Morbidity, Mortality, and Immortality" and focused on this under-addressed problem. PARTICIPANTS discussed communication, workflow, and quality; the complexity of information technology undertakings; the need to integrate all aspects of projects, work environments, and regulatory and policy requirements; and the difficulty of getting all the parts and participants in harmony. While recognizing that there still are technical issues related to functionality and interoperability, discussion affirmed the emerging consensus that problems are due to sociological, cultural, and financial issues, and hence are more managerial than technical. Participants drew on lessons from experience and research in identifying important issues, action items, and recommendations to address the following: what "success" and "failure" mean, what contributes to making successful or unsuccessful systems, how to use failure as an enhanced learning opportunity for continued improvement, how system successes or failures should be studied, and what AMIA should do to enhance opportunities for successes. The workshop laid out a research agenda and recommended action items, reflecting the conviction that AMIA members and AMIA as an organization can take a leadership role to make projects more practical and likely to succeed in health care settings.

Adrenal venous sampling: the learning curve of a single interventionalist with 282 consecutive procedures.

PubMed

Jakobsson, Hugo; Farmaki, Katerina; Sakinis, Augustinas; Ehn, Olof; Johannsson, Gudmundur; Ragnarsson, Oskar

2018-01-01

Primary aldosteronism (PA) is a common cause of secondary hypertension. Adrenal venous sampling (AVS) is the gold standard for assessing laterality of PA, which is of paramount importance to decide adequate treatment. AVS is a technically complicated procedure with success rates ranging between 30% and 96%. The aim of this study was to investigate the success rate of AVS over time, performed by a single interventionalist. This was a retrospective study based on consecutive AVS procedures performed by a single operator between September 2005 and June 2016. Data on serum concentrations of aldosterone and cortisol from right and left adrenal vein, inferior vena cava, and peripheral vein were collected and selectivity index (SI) calculated. Successful AVS was defined as SI > 5. In total, 282 AVS procedures were performed on 269 patients, 168 men (62%) and 101 women (38%), with a mean age of 55±11 years (range, 26-78 years). Out of 282 AVS procedures, 259 were successful, giving an overall success rate of 92%. The most common reason for failure was inability to localize the right adrenal vein (n=16; 76%). The success rates were 63%, 82%, and 94% during the first, second, and third years, respectively. During the last 8 years the success rate was 95%, and on average 27 procedures were performed annually. Satisfactory AVS success rate was achieved after approximately 36 procedures and satisfactory success rate was maintained by performing approximately 27 procedures annually. AVS should be limited to few operators that perform sufficiently large number of procedures to achieve, and maintain, satisfactory AVS success rate.

A Study to Compare the Failure Rates of Current Space Shuttle Ground Support Equipment with the New Pathfinder Equipment and Investigate the Effect that the Proposed GSE Infrastructure Upgrade Might Have to Reduce GSE Infrastructure Failures

NASA Technical Reports Server (NTRS)

Kennedy, Barbara J.

2004-01-01

The purposes of this study are to compare the current Space Shuttle Ground Support Equipment (GSE) infrastructure with the proposed GSE infrastructure upgrade modification. The methodology will include analyzing the first prototype installation equipment at Launch PAD B called the "Pathfinder". This study will begin by comparing the failure rate of the current components associated with the "Hardware interface module (HIM)" at the Kennedy Space Center to the failure rate of the neW Pathfinder components. Quantitative data will be gathered specifically on HIM components and the PAD B Hypergolic Fuel facility and Hypergolic Oxidizer facility areas which has the upgraded pathfinder equipment installed. The proposed upgrades include utilizing industrial controlled modules, software, and a fiber optic network. The results of this study provide evidence that there is a significant difference in the failure rates of the two studied infrastructure equipment components. There is also evidence that the support staff for each infrastructure system is not equal. A recommendation to continue with future upgrades is based on a significant reduction of failures in the new' installed ground system components.

Mechanisms, predictors, and trends of electrical failure of Riata leads.

PubMed

Cheung, Jim W; Al-Kazaz, Mohamed; Thomas, George; Liu, Christopher F; Ip, James E; Bender, Seth R; Siddiqi, Faisal K; Markowitz, Steven M; Lerman, Bruce B

2013-10-01

Riata and Riata ST implantable cardioverter-defibrillator leads have been shown to be prone to structural and electrical failure. To determine predictors, mechanisms, and temporal patterns of Riata/ST lead electrical failure. All 314 patients who underwent Riata/ST lead implantation at our institution with greater than or equal to 90 days of follow-up were studied. The Kaplan-Meier analysis of lead survival was performed. Results from the returned product analysis of explanted leads with electrical lead failure were recorded. During a median follow-up of 4.1 years, the Riata lead electrical failure rate was 6.6%. The rate of externalized conductors among failed leads was 57%. The engineering analysis of 10 explanted leads revealed 5 (50%) leads with electrical failure owing to breach of ethylene tetrafluoroethylene conductor coating. Female gender (hazard ratio 2.7; 95% confidence interval 1.1-6.7; P = .04) and age (hazard ratio 0.95; 95% confidence interval 0.92-0.97; P < .001) were multivariate predictors of lead failure. By using log-log analysis, we noted that the rate of Riata lead failure initially increased exponentially with a power of 2.1 but leads surviving past 4 years had a linear pattern of lead failure with a power of 1.0. Younger age and female gender are independent predictors of Riata lead failure. Loss of integrity of conductor cables with ethylene tetrafluoroethylene coating is an important mode of electrical failure of the Riata lead. Further study of Riata lead failure trends is warranted to guide lead management. © 2013 Heart Rhythm Society. All rights reserved.

Comment on "Synchronization of chaotic systems with delay using intermittent linear state feedback" [Chaos 18, 033122 (2008)].

PubMed

Zhang, Yinping; Wang, Qing-Guo

2008-12-01

In the referenced paper, there is technical carelessness in the third lemma and in the main result. Hence, it is a possible failure when the result is used to design the intermittent linear state feedback controller for exponential synchronization of two chaotic delayed systems.

NASA-DoD Lead-Free Electronics Project

NASA Technical Reports Server (NTRS)

Kessel, Kurt

2007-01-01

The primary technical objective of the project is to undertake comprehensive testing to generate information on failure modes/criteria to better understand the reliability of: Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with lead-free alloys Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with mixed (lead/lead-free) alloys.

Alternative Fuels Data Center: Reliable Temperature Compensation is

Science.gov Websites

Technical Bulletin addresses the potential hazards created by failure of compressed natural gas (CNG ) dispensers that do not accurately compensate for the temperature of the natural gas in vehicle storage containers as they are filled and the history of serious incidents as a result. Accurate temperature

Radiation and shielding study for the International Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Baze, M.; Firminhac, R. H.; Horne, W. E.; Kennedy, R. C.; Measel, P. R.; Sivo, L. L.; Wilkinson, M. C.

1974-01-01

Technical advisory services to ensure integrity of parts and material exposed to energetic particle radiation for the IUE scientific instruments, spacecraft, and subsystems are provided. A significant potential for interference, degradation, or failure for unprotected or sensitive items was found. Vulnerable items were identified, and appropriate tests, changes, and shields were defined.

Why Integrating Technology Has Been Unsuccessful in Kuwait? An Exploratory Study

ERIC Educational Resources Information Center

Alfelaij, Bader

2016-01-01

In Kuwait, unsuccessful attempts to use and integrate technology into classrooms and lecture halls are currently being witnessed in schools and higher education institutions. Such failure is believed to be the consequence of various challenges, such as cultural, technical and contextual challenges. In this exploratory study, the researcher has…

77 FR 54839 - Clarification of Submission of Requests for Relief or Alternatives From the Regulatory...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-06

... the examination or testing, evaluates the susceptibility to known degradation, mechanisms or failure... and applicants have not been supported by adequate descriptive and detailed technical information... attempted. Sections 50.55a(f)(6)(i) and (g)(6)(i) state that the NRC will evaluate determinations that ASME...

Composite-Unit Accelerated Life Testing (CUALT) of Sonar Transducers

DTIC Science & Technology

1979-09-01

Developed and technically defended the Texas Research Institute CUALT plan, Helped prepare sections 5 and 7. Edward Hobaica and Ray Haworth - Developed...le2--Te- TT-Sonar 3R. A. Larmi, E. C. Hobaica , Failure Modes & Effects Analysis for the DT-308’ (now called the DT-605) Hydrophone, EB Div Report No.: U

Understanding Teamwork in Trauma Resuscitation through Analysis of Team Errors

ERIC Educational Resources Information Center

Sarcevic, Aleksandra

2009-01-01

An analysis of human errors in complex work settings can lead to important insights into the workspace design. This type of analysis is particularly relevant to safety-critical, socio-technical systems that are highly dynamic, stressful and time-constrained, and where failures can result in catastrophic societal, economic or environmental…

Sensitivity of fetal RHD screening for safe guidance of targeted anti-D immunoglobulin prophylaxis: prospective cohort study of a nationwide programme in the Netherlands.

PubMed

de Haas, Masja; Thurik, Florentine F; van der Ploeg, Catharina P B; Veldhuisen, Barbera; Hirschberg, Hoang; Soussan, Aicha Ait; Woortmeijer, Heleen; Abbink, Frithjofna; Page-Christiaens, Godelieve C M L; Scheffer, Peter G; Ellen van der Schoot, C

2016-11-07

 To determine the accuracy of non-invasive fetal testing for the RHD gene in week 27 of pregnancy as part of an antenatal screening programme to restrict anti-D immunoglobulin use to women carrying a child positive for RHD DESIGN:  Prospectively monitoring of fetal RHD testing accuracy compared with serological cord blood typing on introduction of the test. Fetal RHD testing was performed with a duplex real time quantitative polymerase chain reaction, with cell-free fetal DNA isolated from 1 mL of maternal plasma The study period was between 4 July 2011 and 7 October 2012. The proportion of women participating in screening was determined.  Nationwide screening programme, the Netherlands. Tests are performed in a centralised setting.  25 789 RhD negative pregnant women.  Sensitivity, specificity, false negative rate, and false positive rate of fetal RHD testing compared with serological cord blood typing; proportion of technical failures; and compliance to the screening programme.  A fetal RHD test result and serological cord blood result were available for 25 789 pregnancies. Sensitivity for detection of fetal RHD was 99.94% (95% confidence interval 99.89% to 99.97%) and specificity was 97.74% (97.43% to 98.02%). Nine false negative results for fetal RHD testing were registered (0.03%, 95% confidence interval 0.01% to 0.06%). In two cases these were due to technical failures. False positive fetal RHD testing results were registered for 225 samples (0.87%, 0.76% to 0.99%). Weak RhD expression was shown in 22 of these cases, justifying anti-D immunoglobulin use. The negative and positive predictive values were 99.91% (95% confidence interval 99.82% to 99.95%) and 98.60% (98.40% to 98.77%), respectively. More than 98% of the women participated in the screening programme.  Fetal RHD testing in week 27 of pregnancy as part of a national antenatal screening programme is highly reliable and can be used to target both antenatal and postnatal anti-D immunoglobulin use. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Structures Division

NASA Technical Reports Server (NTRS)

1997-01-01

The NASA Lewis Research Center Structures Division is an international leader and pioneer in developing new structural analysis, life prediction, and failure analysis related to rotating machinery and more specifically to hot section components in air-breathing aircraft engines and spacecraft propulsion systems. The research consists of both deterministic and probabilistic methodology. Studies include, but are not limited to, high-cycle and low-cycle fatigue as well as material creep. Studies of structural failure are at both the micro- and macrolevels. Nondestructive evaluation methods related to structural reliability are developed, applied, and evaluated. Materials from which structural components are made, studied, and tested are monolithics and metal-matrix, polymer-matrix, and ceramic-matrix composites. Aeroelastic models are developed and used to determine the cyclic loading and life of fan and turbine blades. Life models are developed and tested for bearings, seals, and other mechanical components, such as magnetic suspensions. Results of these studies are published in NASA technical papers and reference publication as well as in technical society journal articles. The results of the work of the Structures Division and the bibliography of its publications for calendar year 1995 are presented.

Structures Division 1994 Annual Report

NASA Technical Reports Server (NTRS)

1996-01-01

The NASA Lewis Research Center Structures Division is an international leader and pioneer in developing new structural analysis, life prediction, and failure analysis related to rotating machinery and more specifically to hot section components in air-breathing aircraft engines and spacecraft propulsion systems. The research consists of both deterministic and probabilistic methodology. Studies include, but are not limited to, high-cycle and low-cycle fatigue as well as material creep. Studies of structural failure are at both the micro- and macrolevels. Nondestructive evaluation methods related to structural reliability are developed, applied, and evaluated. Materials from which structural components are made, studied, and tested are monolithics and metal-matrix, polymer-matrix, and ceramic-matrix composites. Aeroelastic models are developed and used to determine the cyclic loading and life of fan and turbine blades. Life models are developed and tested for bearings, seals, and other mechanical components, such as magnetic suspensions. Results of these studies are published in NASA technical papers and reference publication as well as in technical society journal articles. The results of the work of the Structures Division and the bibliography of its publications for calendar year 1994 are presented.

Novel Dissimilar Joints Between Alloy 800H and 2.25%Cr and 1%Mo Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

DebRoy, Tarasankar

Dissimilar metal joints between ferritic steels and nickel base alloys are currently fabricated using conventional arc welding processes with selected filler metal combinations. The dissimilar metal joints contain abrupt changes in composition over a relatively small distance. Many years of service at elevated temperatures has shown that these welds are susceptible to creep and creep fatigue failures. The primary mechanism for these creep failures involves carbon diffusion from the ferritic steel to the nickel base alloy. As a result, a carbon depleted zone is created that contains very few stable carbides. This work used additive manufacturing (AM) technologies as amore » highly controllable means for reducing carbon migration through theoretically designed, compositionally graded transition joints guided by appropriate thermodynamic, kinetic and heat transfer and fluid flow modeling. The contents of the report include the objectives and tasks set forth by the PI and collaborators, major technical accomplishments throughout the research and additional details in the form of technical publications resulting from the NEUP grant and reports from the collaborating university and national laboratory.« less

Failure rate of inferior alveolar nerve block among dental students and interns

PubMed Central

AlHindi, Maryam; Rashed, Bayan; AlOtaibi, Noura

2016-01-01

Objectives: To report the failure rate of inferior alveolar nerve block (IANB) among dental students and interns, causes of failure, investigate awareness of different IANB techniques, and to report IANB-associated complications. Methods: A 3-page questionnaire containing 13 questions was distributed to a random sample of 350 third to fifth years students and interns at the College of Dentistry, King Saud University, Riyadh, Saudi Arabia on January 2011. It included demographic questions (age, gender, and academic level) and questions on IANB failure frequency and reasons, actions taken to overcome the failure, and awareness of different anesthetic techniques, supplementary techniques, and complications. Results: Of the 250 distributed questionnaires, 238 were returned (68% response rate). Most (85.7%) of surveyed sample had experienced IANB failure once or twice. The participants attributed the failures most commonly (66.45%) to anatomical variations. The most common alternative technique used was intraligamentary injection (57.1%), although 42.8% of the sample never attempted any alternatives. Large portion of the samples stated that they either lacked both knowledge of and training for other techniques (44.9%), or that they had knowledge of them but not enough training to perform them (45.8%). Conclusion: To decrease IANB failure rates for dental students and interns, knowledge of landmarks, anatomical variation and their training in alternatives to IANB, such as the Gow-Gates and Akinosi techniques, both theoretically and clinically in the dental curriculum should be enhanced. PMID:26739980

Failure rate of inferior alveolar nerve block among dental students and interns.

PubMed

AlHindi, Maryam; Rashed, Bayan; AlOtaibi, Noura

2016-01-01

To report the failure rate of inferior alveolar nerve block (IANB) among dental students and interns, causes of failure, investigate awareness of different IANB techniques, and to report IANB-associated complications.   A 3-page questionnaire containing 13 questions was distributed to a random sample of 350 third to fifth years students and interns at the College of Dentistry, King Saud University, Riyadh, Saudi Arabia on January 2011. It included demographic questions (age, gender, and academic level) and questions on IANB failure frequency and reasons, actions taken to overcome the failure, and awareness of different anesthetic techniques, supplementary techniques, and complications.   Of the 250 distributed questionnaires, 238 were returned (68% response rate). Most (85.7%) of surveyed sample had experienced IANB failure once or twice. The participants attributed the failures most commonly (66.45%) to anatomical variations. The most common alternative technique used was intraligamentary injection (57.1%), although 42.8% of the sample never attempted any alternatives. Large portion of the samples stated that they either lacked both knowledge of and training for other techniques (44.9%), or that they had knowledge of them but not enough training to perform them (45.8%).  To  decrease IANB failure rates for dental students and interns, knowledge of landmarks, anatomical variation and their training in alternatives to IANB, such as the Gow-Gates and Akinosi techniques, both theoretically and clinically in the dental curriculum should be enhanced.

Disease management: remote monitoring in heart failure patients with implantable defibrillators, resynchronization devices, and haemodynamic monitors.

PubMed

Abraham, William T

2013-06-01

Heart failure represents a major public health concern, associated with high rates of morbidity and mortality. A particular focus of contemporary heart failure management is reduction of hospital admission and readmission rates. While optimal medical therapy favourably impacts the natural history of the disease, devices such as cardiac resynchronization therapy devices and implantable cardioverter defibrillators have added incremental value in improving heart failure outcomes. These devices also enable remote patient monitoring via device-based diagnostics. Device-based measurement of physiological parameters, such as intrathoracic impedance and heart rate variability, provide a means to assess risk of worsening heart failure and the possibility of future hospitalization. Beyond this capability, implantable haemodynamic monitors have the potential to direct day-to-day management of heart failure patients to significantly reduce hospitalization rates. The use of a pulmonary artery pressure measurement system has been shown to significantly reduce the risk of heart failure hospitalization in a large randomized controlled study, the CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Heart Failure Patients (CHAMPION) trial. Observations from a pilot study also support the potential use of a left atrial pressure monitoring system and physician-directed patient self-management paradigm; these observations are under further investigation in the ongoing LAPTOP-HF trial. All these devices depend upon high-intensity remote monitoring for successful detection of parameter deviations and for directing and following therapy.

The Effectiveness of Mail Survey Techniques in Studies of Semiprofessional Work Groups: Response Rates of Vocational-Technical Teachers.

ERIC Educational Resources Information Center

DeBord, Larry W.

1979-01-01

A study of the factors influencing response rates in survey research--including kind of instrument used and personality and job characteristics of those surveyed--examined response rates to a mailed questionnaire in a sample of vocational-technical teachers and their program directors. Offers suggestions on improving response rates in…

Being on sick leave due to heart failure: self-rated health, encounters with healthcare professionals and social insurance officers and self-estimated ability to return to work.

PubMed

Nordgren, Lena; Söderlund, Anne

2015-01-01

Younger people with heart failure often experience poor self-rated health. Furthermore, poor self-rated health is associated with long-term sick leave and disability pension. Socio-demographic factors affect the ability to return to work. However, little is known about people on sick leave due to heart failure. The aim of this study was to investigate associations between self-rated health, mood, socio-demographic factors, sick leave compensation, encounters with healthcare professionals and social insurance officers and self-estimated ability to return to work, for people on sick leave due to heart failure. This population-based investigation had a cross-sectional design. Data were collected in Sweden in 2012 from two official registries and from a postal questionnaire. In total, 590 subjects, aged 23-67, responded (response rate 45.8%). Descriptive statistics, correlation analyses (Spearman bivariate analysis) and logistic regression analyses were used to investigate associations. Poor self-rated health was strongly associated with full sick leave compensation (OR = 4.1, p < .001). Compared self-rated health was moderately associated with low income (OR =  .6, p =  .003). Good self-rated health was strongly associated with positive encounters with healthcare professionals (OR = 3.0, p =  .022) and to the impact of positive encounters with healthcare professionals on self-estimated ability to return to work (OR = 3.3, p < .001). People with heart failure are sicklisted for long periods of time and to a great extent receive disability pension. Not being able to work imposes reduced quality of life. Positive encounters with healthcare professionals and social insurance officers can be supportive when people with heart failure struggle to remain in working life.

Scaling of coupled dilatancy-diffusion processes in space and time

NASA Astrophysics Data System (ADS)

Main, I. G.; Bell, A. F.; Meredith, P. G.; Brantut, N.; Heap, M.

2012-04-01

Coupled dilatancy-diffusion processes resulting from microscopically brittle damage due to precursory cracking have been observed in the laboratory and suggested as a mechanism for earthquake precursors. One reason precursors have proven elusive may be the scaling in space: recent geodetic and seismic data placing strong limits on the spatial extent of the nucleation zone for recent earthquakes. Another may be the scaling in time: recent laboratory results on axi-symmetric samples show both a systematic decrease in circumferential extensional strain at failure and a delayed and a sharper acceleration of acoustic emission event rate as strain rate is decreased. Here we examine the scaling of such processes in time from laboratory to field conditions using brittle creep (constant stress loading) to failure tests, in an attempt to bridge part of the strain rate gap to natural conditions, and discuss the implications for forecasting the failure time. Dilatancy rate is strongly correlated to strain rate, and decreases to zero in the steady-rate creep phase at strain rates around 10-9 s-1 for a basalt from Mount Etna. The data are well described by a creep model based on the linear superposition of transient (decelerating) and accelerating micro-crack growth due to stress corrosion. The model produces good fits to the failure time in retrospect using the accelerating acoustic emission event rate, but in prospective tests on synthetic data with the same properties we find failure-time forecasting is subject to systematic epistemic and aleatory uncertainties that degrade predictability. The next stage is to use the technology developed to attempt failure forecasting in real time, using live streamed data and a public web-based portal to quantify the prospective forecast quality under such controlled laboratory conditions.

Syndromic surveillance for health information system failures: a feasibility study.

PubMed

Ong, Mei-Sing; Magrabi, Farah; Coiera, Enrico

2013-05-01

To explore the applicability of a syndromic surveillance method to the early detection of health information technology (HIT) system failures. A syndromic surveillance system was developed to monitor a laboratory information system at a tertiary hospital. Four indices were monitored: (1) total laboratory records being created; (2) total records with missing results; (3) average serum potassium results; and (4) total duplicated tests on a patient. The goal was to detect HIT system failures causing: data loss at the record level; data loss at the field level; erroneous data; and unintended duplication of data. Time-series models of the indices were constructed, and statistical process control charts were used to detect unexpected behaviors. The ability of the models to detect HIT system failures was evaluated using simulated failures, each lasting for 24 h, with error rates ranging from 1% to 35%. In detecting data loss at the record level, the model achieved a sensitivity of 0.26 when the simulated error rate was 1%, while maintaining a specificity of 0.98. Detection performance improved with increasing error rates, achieving a perfect sensitivity when the error rate was 35%. In the detection of missing results, erroneous serum potassium results and unintended repetition of tests, perfect sensitivity was attained when the error rate was as small as 5%. Decreasing the error rate to 1% resulted in a drop in sensitivity to 0.65-0.85. Syndromic surveillance methods can potentially be applied to monitor HIT systems, to facilitate the early detection of failures.

75 FR 9203 - Guidance on Preparation of Market-Based Rate Filings and Electric Quarterly Reports by Public...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-01

... Preparation of Market-Based Rate Filings and Electric Quarterly Reports by Public Utilities; Supplemental Notice of Technical Conference February 22, 2010. As announced in the ``Notice of Technical Conference'' issued on January 28, 2010, a technical conference will be held on March 3, 2010, from 9 a.m. to 3 p.m...

Age and admission times as predictive factors for failure of admissions to discharge-stream short-stay units.

PubMed

Shetty, Amith L; Shankar Raju, Savitha Banagar; Hermiz, Arsalan; Vaghasiya, Milan; Vukasovic, Matthew

2015-02-01

Discharge-stream emergency short-stay units (ESSU) improve ED and hospital efficiency. Age of patients and time of hospital presentations have been shown to correlate with increasing complexity of care. We aim to determine whether an age and time cut-off could be derived to subsequently improve short-stay unit success rates. We conducted a retrospective audit on 6703 (5522 inclusions) patients admitted to our discharge-stream short-stay unit. Patients were classified as appropriate or inappropriate admissions, and deemed successful if discharged out of the unit within 24 h; and failures if they needed inpatient admission into the hospital. We calculated short-stay unit length of stay for patients in each of these groups. A 15% failure rate was deemed as acceptable key performance indicator (KPI) for our unit. There were 197 out of 4621 (4.3%, 95% CI 3.7-4.9%) patients up to the age of 70 who failed admission to ESSU compared with 67 out of 901 (7.4%, 95% CI 5.9-9.3%, P < 0.01) of patients over the age of 70, reflecting an increased failure rate in geriatric population. When grouped according to times of admission to the ESSU (in-office 06.00-22.00 hours vs out-of-office 22.00-06.00 hours) no significant difference rates in discharge failure (4.7% vs 5.2%, P = 0.46) were noted. Patients >70 years of age have higher rates of failure after admission to discharge-stream ESSU. Although in appropriately selected discharge-stream patients, no age group or time-band of presentation was associated with increased failure rate beyond the stipulated KPI. © 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

47 CFR 18.207 - Technical report.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Technical report. 18.207 Section 18.207... Applications and Authorizations § 18.207 Technical report. When required by the Commission a technical report...(s) under which the equipment is or will be marketed. (e) A statement of the rated technical...

47 CFR 18.207 - Technical report.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Technical report. 18.207 Section 18.207... Applications and Authorizations § 18.207 Technical report. When required by the Commission a technical report...(s) under which the equipment is or will be marketed. (e) A statement of the rated technical...

47 CFR 18.207 - Technical report.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Technical report. 18.207 Section 18.207... Applications and Authorizations § 18.207 Technical report. When required by the Commission a technical report...(s) under which the equipment is or will be marketed. (e) A statement of the rated technical...

Selected Mildly Obese Donors Can Be Used Safely in Simultaneous Pancreas and Kidney Transplantation.

PubMed

Alhamad, Tarek; Malone, Andrew F; Lentine, Krista L; Brennan, Daniel C; Wellen, Jason; Chang, Su-Hsin; Chakkera, Harini A

2017-06-01

Donor obesity, defined as donor body mass index (D-BMI) of 30 kg/m or greater, has been associated with increased risk of technical failure and poor pancreas allograft outcomes. Many transplant centers establish a threshold of D-BMI of 30 kg/m to decline donor offers for pancreas transplantation. However, no previous studies differentiate the impact of mild (D-BMI, 30-35 kg/m) versus severe obesity (D-BMI, ≥35 kg/m) on pancreas allograft outcomes. We examined Organ Procurement Transplant Network database records for 9916 simultaneous pancreas-kidney transplants (SPKT) performed between 2000 and 2013. We categorized donor body mass index (D-BMI) into 4 groups: 20 to 25 (n = 5724), 25 to 30 (n = 3303), 30 to 35 (n = 751), and 35 to 50 kg/m (n= 138). Associations of D-BMI with pancreas and kidney allograft failure were assessed by multivariate Cox regression adjusted for recipient, donor, and transplant factors. Compared with D-BMI 20 to 25 kg/m, only D-BMI 35 to 50 kg/m was associated with significantly higher pancreas allograft [adjusted hazard ratio [aHR], 1.37; 95% confidence interval (CI], 1.04-1.79] and kidney allograft (aHR, 1.36; CI, 1.02-1.82) failure over the study period (13 years). Donor BMI 30 to 35 kg/m did not impact pancreas allograft (aHR, 0.99; CI, 0.86-1.37) or kidney allograft (aHR, 0.98; CI, 0.84-1.15) failure. Similar patterns were noted at 3 months, and 1, 5, and 10 years posttransplant. These data support that pancreata from mildly obese donors (BMI, 30-35 kg/m) can be safely used for transplantation, with comparable short-term and long-term outcomes as organs from lean donors. Consideration of pancreata from obese donors may decrease the pancreas discard rate.

Forecasting overhaul or replacement intervals based on estimated system failure intensity

NASA Astrophysics Data System (ADS)

Gannon, James M.

1994-12-01

System reliability can be expressed in terms of the pattern of failure events over time. Assuming a nonhomogeneous Poisson process and Weibull intensity function for complex repairable system failures, the degree of system deterioration can be approximated. Maximum likelihood estimators (MLE's) for the system Rate of Occurrence of Failure (ROCOF) function are presented. Evaluating the integral of the ROCOF over annual usage intervals yields the expected number of annual system failures. By associating a cost of failure with the expected number of failures, budget and program policy decisions can be made based on expected future maintenance costs. Monte Carlo simulation is used to estimate the range and the distribution of the net present value and internal rate of return of alternative cash flows based on the distributions of the cost inputs and confidence intervals of the MLE's.

In-Flight Validation of a Pilot Rating Scale for Evaluating Failure Transients in Electronic Flight Control Systems

NASA Technical Reports Server (NTRS)

Kalinowski, Kevin F.; Tucker, George E.; Moralez, Ernesto, III

2006-01-01

Engineering development and qualification of a Research Flight Control System (RFCS) for the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) JUH-60A has motivated the development of a pilot rating scale for evaluating failure transients in fly-by-wire flight control systems. The RASCAL RFCS includes a highly-reliable, dual-channel Servo Control Unit (SCU) to command and monitor the performance of the fly-by-wire actuators and protect against the effects of erroneous commands from the flexible, but single-thread Flight Control Computer. During the design phase of the RFCS, two piloted simulations were conducted on the Ames Research Center Vertical Motion Simulator (VMS) to help define the required performance characteristics of the safety monitoring algorithms in the SCU. Simulated failures, including hard-over and slow-over commands, were injected into the command path, and the aircraft response and safety monitor performance were evaluated. A subjective Failure/Recovery Rating (F/RR) scale was developed as a means of quantifying the effects of the injected failures on the aircraft state and the degree of pilot effort required to safely recover the aircraft. A brief evaluation of the rating scale was also conducted on the Army/NASA CH-47B variable stability helicopter to confirm that the rating scale was likely to be equally applicable to in-flight evaluations. Following the initial research flight qualification of the RFCS in 2002, a flight test effort was begun to validate the performance of the safety monitors and to validate their design for the safe conduct of research flight testing. Simulated failures were injected into the SCU, and the F/RR scale was applied to assess the results. The results validate the performance of the monitors, and indicate that the Failure/Recovery Rating scale is a very useful tool for evaluating failure transients in fly-by-wire flight control systems.

A new kid on the block: The Memory Validity Profile (MVP) in children with neurological conditions.

PubMed

Brooks, Brian L; Fay-McClymont, Taryn B; MacAllister, William S; Vasserman, Marsha; Sherman, Elisabeth M S

2018-06-06

Determining the validity of obtained data is an inherent part of a neuropsychological assessment. The purpose of this study was investigate the failure rate of the Memory Validity Profile (MVP) in a large clinical sample of children and adolescents with neurological diagnoses. Data were obtained from 261 consecutive patients (mean age = 12.0, SD = 3.9, range = 5-19) who were referred for a neuropsychological assessment in a tertiary care pediatric hospital and were administered the MVP. In this sample, 4.6% of youth failed the MVP. Mean administration time for the MVP was 7.4 min, although time to complete was not associated with failure rates. Failure rates were held relatively consistent at approximately 5% across age ranges, diagnoses, and psychomotor processing speed abilities. Having very low, below normal, or above normal intellectual abilities did not alter failure rate on the MVP. However, those with intellectual disability (i.e., IQ<70) had a higher fail rate at 12% on MVP Total Score, but only 6% on the MVP Visual portion. Failure rates on the MVP were associated with lower scores on memory tests. This study provides support for using the MVP in children as young as 5 years with neurological diagnoses.

Effect of Strain Rate on Joint Strength and Failure Mode of Lead-Free Solder Joints

NASA Astrophysics Data System (ADS)

Lin, Jian; Lei, Yongping; Fu, Hanguang; Guo, Fu

2018-03-01

In surface mount technology, the Sn-3.0Ag-0.5Cu solder joint has a shorter impact lifetime than a traditional lead-tin solder joint. In order to improve the impact property of SnAgCu lead-free solder joints and identify the effect of silver content on tensile strength and impact property, impact experiments were conducted at various strain rates on three selected SnAgCu based solder joints. It was found that joint failure mainly occurred in the solder material with large plastic deformation under low strain rate, while joint failure occurred at the brittle intermetallic compound layer without any plastic deformation at a high strain rate. Joint strength increased with the silver content in SnAgCu alloys in static tensile tests, while the impact property of the solder joint decreased with increasing silver content. When the strain rate was low, plastic deformation occurred with failure and the tensile strength of the Sn-3.0Ag-0.5Cu solder joint was higher than that of Sn-0.3Ag-0.7Cu; when the strain rate was high, joint failure mainly occurred at the brittle interface layer and the Sn-0.3Ag-0.7Cu solder joint had a better impact resistance with a thinner intermetallic compound layer.

[The Development and Application of the Orthopaedics Implants Failure Database Software Based on WEB].

PubMed

Huang, Jiahua; Zhou, Hai; Zhang, Binbin; Ding, Biao

2015-09-01

This article develops a new failure database software for orthopaedics implants based on WEB. The software is based on B/S mode, ASP dynamic web technology is used as its main development language to achieve data interactivity, Microsoft Access is used to create a database, these mature technologies make the software extend function or upgrade easily. In this article, the design and development idea of the software, the software working process and functions as well as relative technical features are presented. With this software, we can store many different types of the fault events of orthopaedics implants, the failure data can be statistically analyzed, and in the macroscopic view, it can be used to evaluate the reliability of orthopaedics implants and operations, it also can ultimately guide the doctors to improve the clinical treatment level.

Evaluation and treatment of failed shoulder instability procedures.

PubMed

Ho, Anthony G; Gowda, Ashok L; Michael Wiater, J

2016-09-01

Management of the unstable shoulder after a failed stabilization procedure can be difficult and challenging. Detailed understanding of the native shoulder anatomy, including its static and dynamic restraints, is necessary for determining the patient's primary pathology. In addition, evaluation of the patient's history, physical exam, and imaging is important for identifying the cause for failure after the initial procedure. Common mistakes include under-appreciation of bony defects, failure to recognize capsular laxity, technical errors, and missed associated pathology. Many potential treatment options exist for revision surgery, including open or arthroscopic Bankart repair, bony augmentation procedures, and management of Hill Sachs defects. The aim of this narrative review is to discuss in-depth the common risk factors for post-surgical failure, components for appropriate evaluation, and the different surgical options available for revision stabilization. Level of evidence Level V.

A stitch in time saves nine: external quality assessment rounds demonstrate improved quality of biomarker analysis in lung cancer

PubMed Central

Keppens, Cleo; Tack, Véronique; Hart, Nils ‘t; Tembuyser, Lien; Ryska, Ales; Pauwels, Patrick; Zwaenepoel, Karen; Schuuring, Ed; Cabillic, Florian; Tornillo, Luigi; Warth, Arne; Weichert, Wilko; Dequeker, Elisabeth

2018-01-01

Biomarker analysis has become routine practice in the treatment of non-small cell lung cancer (NSCLC). To ensure high quality testing, participation to external quality assessment (EQA) schemes is essential. This article provides a longitudinal overview of the EQA performance for EGFR, ALK, and ROS1 analyses in NSCLC between 2012 and 2015. The four scheme years were organized by the European Society of Pathology according to the ISO 17043 standard. Participants were asked to analyze the provided tissue using their routine procedures. Analysis scores improved for individual laboratories upon participation to more EQA schemes, except for ROS1 immunohistochemistry (IHC). For EGFR analysis, scheme error rates were 18.8%, 14.1% and 7.5% in 2013, 2014 and 2015 respectively. For ALK testing, error rates decreased between 2012 and 2015 by 5.2%, 3.2% and 11.8% for the fluorescence in situ hybridization (FISH), FISH digital, and IHC subschemes, respectively. In contrast, for ROS1 error rates increased between 2014 and 2015 for FISH and IHC by 3.2% and 9.3%. Technical failures decreased over the years for all three markers. Results show that EQA contributes to an ameliorated performance for most predictive biomarkers in NSCLC. Room for improvement is still present, especially for ROS1 analysis. PMID:29755669

Discrepant perceptions of communication, teamwork and situation awareness among surgical team members.

PubMed

Wauben, L S G L; Dekker-van Doorn, C M; van Wijngaarden, J D H; Goossens, R H M; Huijsman, R; Klein, J; Lange, J F

2011-04-01

To assess surgical team members' differences in perception of non-technical skills. Questionnaire design. Operating theatres (OTs) at one university hospital, three teaching hospitals and one general hospital in the Netherlands. Sixty-six surgeons, 97 OT nurses, 18 anaesthetists and 40 nurse anaesthetists. All surgical team members, of five hospitals, were asked to complete a questionnaire and state their opinion on the current state of communication, teamwork and situation awareness at the OT. Ratings for 'communication' were significantly different, particularly between surgeons and all other team members (P ≤ 0.001). The ratings for 'teamwork' differed significantly between all team members (P ≤ 0.005). Within 'situation awareness' significant differences were mainly observed for 'gathering information' between surgeons and other team members (P < 0.001). Finally, 72-90% of anaesthetists, OT nurses and nurse anaesthetists rated routine team briefings and debriefings as inadequate. This study shows discrepancies on many aspects in perception between surgeons and other surgical team members concerning communication, teamwork and situation awareness. Future research needs to ascertain whether these discrepancies are linked to greater risk of adverse events or to process as well as systems failures. Establishing this link would support implementation and use of complex team interventions that intervene at multiple levels of the healthcare system.

[Esophagojejunal anastomoses with the EEA stapler after total gastrectomy. Technic and immediate results apropos of a recent series of 32 cases].

PubMed

Le Treut, Y P; Delpero, J R; Sabiani, P; Berthet, B; Bozon-Verduraz, E; Pol, B; Bricot, R

1987-12-01

32 consecutive total gastrectomies for cancer (20 extended total gastrectomies) were carried out through an abdominal approach. Reconstruction using a Rouxen-Y loop (28 cases) or an interposed jejunal loop (four cases) was done with an EEA stapled oesophago jejunostomy: 25 end to side and 5 end to end anastomosis were performed and two technical failures led to complete manual anastomosis. All patients have had post-operative X-ray examination: there was no anastomotic leakage in this series, even in the 3 patients (10%) who have died during the post-operative course. A critical study of this series and eight others one from elsewhere is presented: it is concluded that the stapling device allows an easier and safer oesophagojejunostomy than manual procedure, when great care is taken of technical details.

25 CFR 163.62 - Annual funding needs assessment and rating.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 25 Indians 1 2012-04-01 2011-04-01 true Annual funding needs assessment and rating. 163.62 Section... REGULATIONS Alaska Native Technical Assistance Program § 163.62 Annual funding needs assessment and rating. (a) Each year, the Secretary will request a technical assistance project needs assessment from ANCSA...

25 CFR 163.62 - Annual funding needs assessment and rating.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 1 2014-04-01 2014-04-01 false Annual funding needs assessment and rating. 163.62... FORESTRY REGULATIONS Alaska Native Technical Assistance Program § 163.62 Annual funding needs assessment and rating. (a) Each year, the Secretary will request a technical assistance project needs assessment...

25 CFR 163.62 - Annual funding needs assessment and rating.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 1 2011-04-01 2011-04-01 false Annual funding needs assessment and rating. 163.62... FORESTRY REGULATIONS Alaska Native Technical Assistance Program § 163.62 Annual funding needs assessment and rating. (a) Each year, the Secretary will request a technical assistance project needs assessment...

25 CFR 163.62 - Annual funding needs assessment and rating.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 1 2013-04-01 2013-04-01 false Annual funding needs assessment and rating. 163.62... FORESTRY REGULATIONS Alaska Native Technical Assistance Program § 163.62 Annual funding needs assessment and rating. (a) Each year, the Secretary will request a technical assistance project needs assessment...

25 CFR 163.62 - Annual funding needs assessment and rating.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Annual funding needs assessment and rating. 163.62... FORESTRY REGULATIONS Alaska Native Technical Assistance Program § 163.62 Annual funding needs assessment and rating. (a) Each year, the Secretary will request a technical assistance project needs assessment...

The Path to Convergence: Design, Coordination and Social Issues in the Implementation of a Middleware Data Broker.

NASA Astrophysics Data System (ADS)

Slota, S.; Khalsa, S. J. S.

2015-12-01

Infrastructures are the result of systems, networks, and inter-networks that accrete, overlay and segment one another over time. As a result, working infrastructures represent a broad heterogeneity of elements - data types, computational resources, material substrates (computing hardware, physical infrastructure, labs, physical information resources, etc.) as well as organizational and social functions which result in divergent outputs and goals. Cyber infrastructure's engineering often defaults to a separation of the social from the technical that results in the engineering succeeding in limited ways, or the exposure of unanticipated points of failure within the system. Studying the development of middleware intended to mediate interactions among systems within an earth systems science infrastructure exposes organizational, technical and standards-focused negotiations endemic to a fundamental trait of infrastructure: its characteristic invisibility in use. Intended to perform a core function within the EarthCube cyberinfrastructure, the development, governance and maintenance of an automated brokering system is a microcosm of large-scale infrastructural efforts. Points of potential system failure, regardless of the extent to which they are more social or more technical in nature, can be considered in terms of the reverse salient: a point of social and material configuration that momentarily lags behind the progress of an emerging or maturing infrastructure. The implementation of the BCube data broker has exposed reverse salients in regards to the overall EarthCube infrastructure (and the role of middleware brokering) in the form of organizational factors such as infrastructural alignment, maintenance and resilience; differing and incompatible practices of data discovery and evaluation among users and stakeholders; and a preponderance of local variations in the implementation of standards and authentication in data access. These issues are characterized by their role in increasing tension or friction among components that are on the path to convergence and may help to predict otherwise-occluded endogenous points of failure or non-adoption in the infrastructure.

Mechanistic analysis of time-dependent failure of oxynitride glass-joined silicon nitride below 1000 degree C

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Brien, M.H.; Coon, D.M.

Time-dependent failure at elevated temperatures currently governs the service life of oxynitride glass-joined silicon nitride. Creep, devitrification, stress- aided oxidation-controlled slow crack growth, and viscous cabitation-controlled failure are examined as possible controlling mechanisms. Creep deformation failure is observed above 1000{degrees}C. Fractographic evidence indicates cavity formation and growth below 1000{degrees}C. Auger electron spectroscopy verified that the oxidation rate of the joining glass is governed by the oxygen supply rate. Time-to-failure data and those predicted using the Tsai and Raj, and Raj and Dang viscous cavitation models. It is concluded that viscous relaxation and isolated cavity growth control the rate of failuremore » in oxynitride glass-filled silicon nitride joints below 1000{degrees}C. Several possible methods are also proposed for increasing the service lives of these joints.« less

Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

PubMed

De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

2017-02-16

Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator (ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation ("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction (not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a non-prospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries (GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.

Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

PubMed Central

De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

2017-01-01

Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator (ICD) leads. Conductor externalization is a “unique” failure mechanism: Cables externalize through the insulation (“inside-out” abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction (not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a non-prospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries (GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads. PMID:28255544