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During laser paint stripping of certain materials, flames could occur that may partially block the laser beam attenuating its intensity and contaminate the optics in addition to fire hazards. This paper demonstrates a laser paint stripping (LPS) technique that effectively suppressed combustion flames, plasma and sparks during the process. The samples used were aluminium alloy sheets with multi-layer paint coatings, provided by CRRC Changchun Railway Vehicles Co., Ltd. The laser beam was defocused to decrease the laser fluence and avoid the formation of sparks, while an inert gas, argon, was blown against the processed area to reduce the heat and oxygen around the beam material interaction zone and hence avoid the formation of combustion flames. The scanning speed of the laser beam was carefully controlled to ensure an appropriate pulse overlap and prevent the aluminium alloy substrate from being overheated. The results show that the painting was effectively removed with significant suppression of flames and sparks during the processing.

Background: Pyrotinib is a novel irreversible pan-ErbB receptor tyrosine kinase inhibitor. Evidence of the efficacy of pyrotinib-based treatments for HER2-positive metastatic breast cancer (MBC) in patients exposed to lapatinib is limited.Methods: Ninety-four patients who received pyrotinib as a third- or higher-line treatment for HER2-positive MBC were included in this retrospective study. The primary and secondary endpoints were overall survival (OS) and progression‐free survival (PFS). Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) analysis were implemented to balance important patient characteristics between groups.Results: Thirty (31.9%) patients were pretreated with lapatinib and subsequently received pyrotinib as an anti-HER2 treatment, and 64 (68.1%) patients did not receive this treatment. The OS and PFS indicated a beneficial trend in lapatinib-naive group compared to lapatinib-treated group in either the original cohort (PFS: 9.02 vs 6.36 months, p = 0.05; OS: 20.73 vs 14.35 months, p = 0.08) or the PSM (PFS: 9.02 vs 6.08 months, p = 0.07; OS: 19.07 vs 18.00 months, p = 0.61) or IPTW (PFS: 9.90 vs 6.17 months, p = 0.05; OS: 19.53 vs 15.10 months, p = 0.08) cohorts. Subgroup analyses demonstrated lapatinib treatment-related differences in PFS in the premenopausal subgroup and the no prior trastuzumab treatment subgroup, but no significant differences were observed in OS.Conclusion: Pyrotinib-based therapy demonstrated promising effects in HER2-positive MBC patients in a real-world study, especially in lapatinib-naive patients, and also some activity in lapatinib-treated patients.

A singly fed, electrically small, planar antenna that generates a quasi-isotropic radiation pattern is investigated. The antenna consists of a folded dipole, a pair of capacitively loaded loops (CLLs), and a coplanar stripline (CPS), which are printed on the top and bottom surfaces of a single-layer printed circuit board. Through near-field coupling with the driven CPS, the folded dipole and CLLs are both effectively excited and behave like an electric dipole and a magnetic dipole, respectively. A quasi-isotropic radiation pattern can therefore be obtained by combining the two orthogonal dipoles with the same radiation intensities and quadrature phases. To verify the idea, a prototype operating at 2.4 GHz is designed, fabricated, and measured. It has been shown that this electrically small antenna (0.165 × 0.164 × 0.006 λ 3, ka = 0.73) has a −10 dB impedance bandwidth of 0.99%, a total efficiency of ∼90%, and a nearly isotropic pattern with the difference between the maximum and minimum radiated power densities given by ∼3 dB over the entire spherical radiating surface.

Rationale: Dyspnea is a common and distressing physical symptom among patients in the ICU and may be underdetected and undertreated. Objectives: To determine the frequency of dyspnea relative to pain, the accuracy of nurses and personal caregiver dyspnea ratings relative to patient-reported dyspnea, and the relationship between nurse-detected dyspnea and treatment. Methods: This was an observational study of patients (n = 138) hospitalized in a medical ICU (MICU). Nurses and patients’ personal caregivers at the bedside reported on their perception of patients’ symptoms. Measurements and Main Results: Dyspnea was assessed by patients, caregivers, and nurses with a numerical rating scale. Across all three raters, the frequency of moderate to severe dyspnea was similar or greater than that of pain (P

Objectives: Advanced modeling techniques have been employed by BCBSLA to predict the risk of hospitalization (ROH) among its members. BCBSLA noted a strong association between members who were predicted as “high risk” in their ROH AI Predictive Model and members who actually had a COVID-19 admission. As a result, BCBSLA was asked to create a simplified model that could extend to the entire state of Louisiana knowing that detailed member data would not be available to score Louisiana’s entire population. Methods: The current ROH model employed by BCBSLA for its members was simplified for State use by focusing on available health factors that could be easily assessed. The simplified model was tested using 2019 BCBSLA membership to predict all future hospitalizations between Jan-Jun 2020. Results: The factors chosen for the new simplified model were age, comorbid conditions (diseases of the circulatory system, Hypertension, etc.) and particular events such as hospital or skilled nursing home facility admission within the past 12 months. The simplified model was shown to be highly predictive of future all-cause hospitalizations. The top 20% of predicted high risk members accounted for 70% of all admissions;AUC was very good at 0.89. The model was also predictive of COVID-19 admissions on a naive population. The top 20% of members captured nearly 50% of COVID-19 admissions, AUC 0.74. The model performance was good considering early COVID-19 admissions were likely misclassified in claims data. Conclusions: Using simplified rules, BCBSLA was able to modify their current ROH model so that Louisiana’s health department could identify patients who would be at the highest risk for hospitalized if they contracted COVID-19.

Caring for patients at the end of life is emotionally taxing and may contribute to burnout. Nevertheless, little is known about the factors associated with emotional distress in intensive care unit (ICU) nurses.To identify patient and family factors associated with nurses' emotional distress in caring for dying patients in the ICU.One hundred nurses who cared for 200 deceased ICU patients at two large academic medical centers in the Northeast United States were interviewed about patients' psychological and physical symptoms, their reactions to those patient experiences (e.g., emotional distress), and perceived factors contributing to their emotional distress. Logistic regression analyses modeled nurses' emotional distress as a function of patient symptoms and care.Patients' overall quality of death (odds ratio [OR], 3.08; 95% confidence interval [CI], 1.31-7.25), suffering (OR, 2.34; CI, 1.03-5.29), and loss of dignity (OR, 2.95; CI, 1.19-7.29) were significantly associated with nurse emotional distress. Some 40.5% (79 of 195) of nurses identified families' fears of patient death, and 34.4% (67 of 195) identified families' unrealistic expectations as contributing to their own emotional distress.Patients' emotional distress, physical distress, and perceived quality of death are associated with nurse emotional distress. Unrealistic family expectations for the patient may be a source of nurse emotional distress. Improving patients' quality of death, including enhancing their dignity, reducing their suffering, and promoting acceptance of an impending death among family members may improve the emotional health of nurses.

Background The use of Do-Not-Resuscitate (DNR) orders has increased but many are placed late in the dying process. This study is to determine the association between the timing of DNR order placement in the intensive care unit (ICU) and nurses’ perceptions of patients’ distress and quality of death. Methods 200 ICU patients and the nurses (n = 83) who took care of them during their last week of life were enrolled from the medical ICU and cardiac care unit of New York Presbyterian Hospital/Weill Cornell Medicine in Manhattan and the surgical ICU at the Brigham and Women’s Hospital in Boston. Nurses were interviewed about their perceptions of the patients’ quality of death using validated measures. Patients were divided into 3 groups—no DNR, early DNR, late DNR placement during the patient’s final ICU stay. Logistic regression analyses modeled perceived patient quality of life as a function of timing of DNR order placement. Patient’s comorbidities, length of ICU stay, and procedures were also included in the model. Results 59 patients (29.5%) had a DNR placed within 48 hours of ICU admission (early DNR), 110 (55%) placed after 48 hours of ICU admission (late DNR), and 31 (15.5%) had no DNR order placed. Compared to patients without DNR orders, those with an early but not late DNR order placement had significantly fewer non-beneficial procedures and lower odds of being rated by nurses as not being at peace (Adjusted Odds Ratio namely AOR = 0.30; [CI = 0.09–0.94]), and experiencing worst possible death (AOR = 0.31; [CI = 0.1–0.94]) before controlling for procedures; and consistent significance in severe suffering (AOR = 0.34; [CI = 0.12–0.96]), and experiencing a severe loss of dignity (AOR = 0.33; [CI = 0.12–0.94]), controlling for non-beneficial procedures. Conclusions Placement of DNR orders within the first 48 hours of the terminal ICU admission was associated with fewer non-beneficial procedures and less perceived suffering and loss of dignity, lower odds of being not at peace and of having the worst possible death.

Background:Ear cartilage piercing is increasingly popular and has a significant complication rate. Contrary to popular belief, there are no minimum qualifications required to practice ear piercing. This study evaluated ear cartilage piercing practices in London, UK.Method:Practitioners at 25 piercing parlours completed a telephone questionnaire assessing piercing practice.Results:Ninety-six per cent of practitioners were aware of the risk of infection post-piercing. Four per cent, 12 per cent and 0 per cent of practitioners were aware of keloid scarring, hypertrophic scarring and cauliflower ear respectively. No practitioners were aware of any other complications. Their consent forms did not document any ear cartilage complications. Twenty-eight per cent of participants advised clients to seek medical attention following a complication. Forty per cent did not provide written post-piercing guidance.Conclusion:Piercing practitioners were insufficiently aware of ear cartilage piercing complications. It is unlikely that informed consent was obtained prior to piercing. The post-piercing practice of the majority of parlours did not follow published national guidance.

SummaryIntroduction Previous studies have indicated that a deletion on the short arm of chromosome 1 negatively predicts survival in patients with multiple myeloma (MM). Due to the small sample size in each study, we performed this meta-analysis to comprehensively investigate the association between the 1p deletion and survival in patients with MM. Methods A literature search was conducted in both foreign and Chinese databases, including SinoMed, CNKI, Wanfang, PubMed, EMBASE, and Scopus. Hazard ratios (HR) with 95% confidence intervals (CI) for overall survival (OS) and progression-free survival (PFS) in 11 eligible articles were extracted or calculated to analyze the pooled HR, which was estimated by fixed-effect or random-effect models based on the heterogeneity between included articles. A subgroup analysis and a meta-regression were conducted, and Galbraith plots were generated to examine any possible heterogeneity. Results The HRs for OS were available in nine articles, whereas five articles discussed HRs for PFS. The HR with 95%CI was 1.989 (95%CI 1.522–2.600, P = 0.017, I2 = 57.1%) when comparing the OS of patients with 1p deletion with the OS of those without this deletion. For PFS, 1p deletion still predicted a poor prognosis (HR 2.11, 95%CI 1.54–2.88, P = 0.292, I2 = 19.3%). Moreover, the subgroup analysis suggested that either the deleted gene on 1p or techniques for detecting chromosome abnormalities contributed to the heterogeneity, which was partially consistent with the results derived from a meta-regression analysis and the Galbraith plot method. Conclusion Our meta-analysis provides globally quantifiable confirmation of the adverse prognostic role of 1p deletion in OS and PFS for patients with MM.

A new era has emerged in rectal cancer surgery--transanal total mesorectal excision (TME). Various platforms have been used to facilitate this novel approach, including transanal minimally invasive surgery (TAMIS) and transanal endoscopic microsurgery. We have previously reported the use of TAMIS-TME. This is a report of the first human case of robotic-assisted transanal surgery for TME.

An increasing number of studies have shown that PUMA and C-myb signaling pathways are involved in various human cancers including colon carcinomas. However, few studies have examined gallbladder cancer specimens, and little is known about the clinical and pathological significance signaling changes may have in gallbladder adenocarcinoma. This study has investigated the expression of PUMA and C-myb in benign and malignant lesions of gallbladder and its pathological significance. Tissue specimens from 108 gallbladder adenocarcinoma patients, 46 adjacent tissues, 15 cases of adenomatous polyps, and 35 surgical specimens from chronic cholecystitis patients were routinely paraffin embedded and sectioned. PUMA and C-myb expressions were detected with EnVision immunohistochemistry. Positive rates of PUMA and C-myb are significantly higher in gallbladder adenocarcinoma tissues than that in the other three (P

The mechanical and electronic properties of the heterojunction formed by (4, 4) carbon nanotube (CNT) and (4, 4) silicon carbide nanotube (SiCNT) have been studied by using first-principles density functional theory. It is found that the Young’s modulus of the heterojunction is mainly determined by that of SiCNT. The SiC/C nanotube heterojunction is broken near the junction interface with applying a relative large uniaxial strain along the axial direction, and then forming a SiC cage. Band structure shows that (4, 4) SiC/C nanotube heterojunction is a semiconductor with direct band gap. Both valence band maximum and conduction band minimum originate from CNT segment. The effect of CNT and SiCNT length on the electronic structures of the nanotube heterojunction is investigated. The Schottky barrier of the nanotube heterojunction is also estimated.

Objectives Patients with systemic lupus erythematosus (SLE) refractory to conventional immunosuppression suffer substantial morbidity and mortality due to active disease and treatment toxicity. Immunoablation followed by autologous stem cell transplantation (ASCT) is a novel therapeutic strategy that potentially offers new hope to these patients. Methods This retrospective survey reviews the efficacy and safety of ASCT in 28 SLE patients from eight centres reported to the European Group for Blood and Marrow Transplantation (EBMT) registry between 2001 and 2008. Results Median disease duration before ASCT was 52 (nine to 396) months, 25/28 SLE patients (89%) were female, age 29 (16–48) years. At the time of ASCT, eight (one to 11) American College of Rheumatology (ACR) diagnostic criteria for SLE were present and 17 (60%) patients had nephritis. Peripheral blood stem cells were mobilized with cyclophosphamide and granulocyte-colony stimulating factor in 93% of patients, and ex vivo CD34 stem cell selection was performed in 36%. Conditioning regimens were employed with either low ( n = 10) or intermediate (18) intensities. With a median follow-up of 38 (one to 110) months after ASCT, the five-year overall survival was 81 ± 8%, disease-free survival was 29 ± 9%, relapse incidence (RI) was 56 ± 11% and non-relapse mortality was 15 ± 7%. Graft manipulation by CD34+ selection was associated with a lower RI ( p = 0.001) on univariate analysis. There were five deaths within two years after ASCT: three caused by infection, one by secondary autoimmune disease and one by progressive SLE. Conclusions Our data further support the concept of immunoablation and ASCT to re-induce long-term clinical and serologic remissions in refractory SLE patients even in the absence of maintenance therapy. This study also suggests a beneficial effect of ex vivo graft manipulation on prevention of relapses post-transplantation in SLE.

Surgery alone is curative for most children with localized MYCN-non-amplified neuroblastoma. However, 10–15% will develop recurrent loco-regional disease, and very rarely, patients will relapse metastatically. Currently, it is not possible to predict which child with localized, MYCN-non-amplified neuroblastoma will develop disseminated disease. We report two children who presented with favorable biology, localized neuroblastoma and subsequently relapsed with metastatic disease after treatment with surgery. Whole-genome DNA copy number analyses performed on the diagnostic tumors identified 15 (case 1) and 8 (case 2) segmental chromosomal alterations. Further analysis of the prognostic value of whole-genome analysis in children with localized neuroblastoma is warranted. Pediatr Blood Cancer 2013;60:332–335. © 2012 Wiley Periodicals, Inc.

OBJECTIVES This study examined associations between prenatal drug exposures and congenital organ system malformation diagnoses in newborns (at birth) and infants (hospitalizations after birth up to 30 days of age) in Kentucky. METHODS Data were obtained from Kentucky inpatient hospitalization records for newborns and for infants from 2009 to 2013. Prenatal drug exposures and congenital anomalies were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes for prenatal drug exposures (760.70-760.79; 304; 779.5) and congenital anomalies (740-759). Descriptive analyses and logistic regression were performed. RESULTS Neonatal abstinence syndrome was the most frequent prenatal drug exposure-related diagnosis in newborns (1%). Cardiac and circulatory malformation diagnoses were significantly elevated in newborns prenatally exposed to drugs compared with cardiac and circulatory malformation diagnoses in newborns with no prenatal drug exposures (P < 0.0001); genital and urinary anomalies also were significantly elevated among newborns with prenatal drug exposures (P < 0.05). Newborns and infants diagnosed as having congenital malformations who were prenatally exposed to drugs had significantly extended hospitalization stays and higher total hospitalization charges compared with newborns and infants diagnosed as having congenital malformations who were not prenatally exposed to drugs (P < 0.0001). CONCLUSIONS Further research is needed to identify specific risk factors (eg, drug classes, tobacco) and toxicities (eg, intake amount, frequency of intake, drug metabolism) associated with congenital malformation diagnoses following prenatal exposure to drugs.

Precise tailoring of optical vector beams is demonstrated, shaping their focal electric fields and used to create complex laser micro-patterning on a metal surface. A Spatial Light Modulator (SLM) and a micro-structured S-waveplate were integrated with a picosecond laser system and employed to structure the vector fields into radial and azimuthal polarizations with and without a vortex phase wavefront as well as superposition states. Imprinting Laser Induced Periodic Surface Structures (LIPSS) elucidates the detailed vector fields around the focal region. In addition to clear azimuthal and radial plasmon surface structures, unique, variable logarithmic spiral micro-structures with a pitch Λ ∼1μm, not observed previously, were imprinted on the surface, confirming unambiguously the complex 2D focal electric fields. We show clearly also how the Orbital Angular Momentum(OAM) associated with a helical wavefront induces rotation of vector fields along the optic axis of a focusing lens and confirmed by the observed surface micro-structures.

Purpose: To investigate and compare the quantitative accuracy of 90Y imaging across different generation PET/CT scanners, for the purpose of dosimetry after radioembolization with resin microspheres. Methods: A strict experimental and imaging protocol was followed by 47 international sites using the NEMA 2007/IEC 2008 PET body phantom with an 8-to-1 sphere-to-background ratio of 90Y solution. The phantom was imaged over a 7-day period (activity ranging from 0.5 to 3.0 GBq) and all reconstructed data were analysed at a core laboratory for consistent processing. Quantitative accuracy was assessed through measures of total phantom activity, activity concentration in background and hot spheres, misplaced counts in a nonradioactive insert, and background variability. Results: Of the 69 scanners assessed, 37 had both time-of-flight (ToF) and resolution recovery (RR) capability. These current generation scanners from GE, Philips and Siemens could reconstruct background concentration measures to within 10 % of true values over the evaluated range, with greater deviations on the Philips systems at low count rates, and demonstrated typical partial volume effects on hot sphere recovery, which dominated spheres of diameter 20 mm in diameter, activity concentrations were consistently underestimated by about 20 %. Non-ToF scanners from GE Healthcare and Siemens were capable of producing accurate measures, but with inferior quantitative recovery compared with ToF systems. Conclusion: Current generation ToF scanners can consistently reconstruct 90Y activity concentrations, but they underestimate activity concentrations in small structures (≤37 mm diameter) within a warm background due to partial volume effects and constraints of the reconstruction algorithm. At the highest count rates investigated, measures of background concentration (about 300 kBq/ml) could be estimated on average to within 1 %, 5 % and 2 % for GE Healthcare (all-pass filter, RR + ToF), Philips (4i8s ToF) and Siemens (2i21s all-pass filter, RR + ToF) ToF systems, respectively. Over the range of activities investigated, comparable performance between GE Healthcare and Siemens ToF systems suggests suitability for quantitative analysis in a scenario analogous to that of postradioembolization imaging for treatment of liver cancer., 0, SCOPUS: ar.j, info:eu-repo/semantics/published

Aims The aim of this study was to investigate the relationship between RhoA expression and clinic pathological parameters of hepatocellular carcinoma (HCC), and to evaluate the prognostic value of RhoA for HCC patients. Methods Three methods, including reverse transcription and polymerase chain reaction, Western blot and immunohistochemical staining were employed to detect RhoA expression in 128 HCC specimens. The correlation between RhoA expression and clinicopathologic outcome, and prognostic value of RhoA for HCC patients were analyzed. Results HCC tissues revealed significantly higher levels of both RhoA mRNA and protein than pericarcinomatous liver tissues (PCLT) (P = 0.001). The mRNA and protein expression levels of RhoA in HCC tissues showed strongly positive correlation (correlation coefficient = 0.712, P = 0.01). There was significant correlation among RhoA mRNA and protein overexpression, and venous invasion (P = 0.009 and P = 0.040, respectively) and cell differentiation (P = 0.021 and P = 0.017). HCC patients with RhoA-positive expression showed a significantly poor prognosis than those with RhoA-negative expression (P = 0.039). Conclusions Our data strongly suggested that increased RhoA expression in HCC correlated with venous invasion and cell differentiation of HCC, overexpression of RhoA indicated a poor prognosis in HCC patients.

Over the last decade, hematopoietic stem cells transplantation (HSCT) has been increasingly used in the treatment of severe progressive autoimmune diseases. We report a retrospective survey of 183 multiple sclerosis (MS) patients, recorded in the database of the European Blood and Marrow Transplantation Group (EBMT). Transplant data were available from 178 patients who received an autologous graft. Overall, transplant related mortality (TRM) was 5.3% and was restricted to the period 1995-2000, with no further TRM reported since then. Busulphan-based regimens were significantly associated with TRM. Clinical status at the time of transplant and transplant techniques showed some correlations with toxicity. No toxic deaths were reported among the 53 patients treated with the BEAM (carmustine, etoposide, cytosine-arabinoside, melphalan)/antithymocyte globulin (ATG) regimen without graft manipulation, irrespective of their clinical condition at the time of the transplant. Improvement or stabilization of neurological conditions occurred in 63% of patients at a median follow-up of 41.7 months, and was not associated with the intensity of the conditioning regimen. In this large series, HSCT was shown as a promising procedure to slow down progression in a subset of patients affected by severe, progressive MS; the safety and feasibility of the procedure can be significantly improved by appropriate patient selection and choice of transplant regimen.

Determining the most appropriate inputs to a model has a significant impact on the performance of the model and associated algorithms for classification, prediction, and data analysis. Previously, we proposed an algorithm ICAIVS which utilizes independent component analysis (ICA) as a preprocessing stage to overcome issues of dependencies between inputs, before the data being passed through to an input variable selection (IVS) stage. While we demonstrated previously with artificial data that ICA can prevent an overestimation of necessary input variables, we show here that mixing between input variables is common in real-world data sets so that ICA preprocessing is useful in practice. This experimental test is based on new measures introduced in this paper. Furthermore, we extend the implementation of our variable selection scheme to a statistical dependency test based on mutual information and test several algorithms on Gaussian and sub-Gaussian signals. Specifically, we propose a novel method of quantifying linear dependencies using ICA estimates of mixing matrices with a new linear mixing measure (LMM).

11 C-metomidate PET-CT scanning can identify aldosterone-producing adenomas after unsuccessful lateralisation with CT/MRI and adrenal venous sampling

The translocation t(8;14)(q24;q11) has been described at the cytogenetic and molecular level in pediatric cases of T-cell leukemia/lymphoma [1]. Although infrequent, the cases reported show a very ...

In China, research and development of air-rail intermodality transportation has not been fleshed out. This paper aims to provide a theoretical support for the development of air-rail intermodality. Firstly, the concept of air-rail intermodality system is put forward. Without regard to management system and technical factors, but from a logical point of system function, we describe the internal structure of the system using hierarchical data flow diagram (DFD) and process oriented method for the first time. Based on the function of air-rail intermodality system, the top-level logical architecture framework is built, which is composed of seven subsystems. They are defined and explained respectively. At last, the two main service modules- integrated ticketing system and through baggage handling system are described in detail.

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is an autosomal recessive disorder that leads to a defect in fatty acid oxidation.ACADMis the only candidate gene causing MCAD deficiency. A single nucleotide change, c.985A>G, occurring at exon 11 of theACADMgene, is the most prevalent mutation. In this study, we report a Caucasian family with multiple MCADD individuals. DNA sequence analysis of theACADMgene performed in this family revealed that two family members showing mild MCADD symptoms share the same novel change in exon 11, c.1052C>T, resulting in a threonine-to-isoleucine change. The replacement is a nonconservative amino acid change that occurs in the C-terminal all-alpha domain of the MCAD protein. Here we report the finding of a novel missense mutation, c.1052C>T (p.Thr326Ile), in theACADMgene. To our knowledge, c.1052C>T has not been previously reported in the literature or in any of the current databases we utilize. We hypothesize that this particular mutation in combination with p.Lys304Glu results in an intermediate clinical phenotype of MCADD.

The space and time variations of the light emission in a macroscopic plasma display panel (PDP) discharge cell have been studied with an image-intensified charge-coupled device. The discharge cell is similar to a real PDP cell with a coplanar electrode configuration. The cell dimensions are on the order of 100 times larger than those of a real PDP cell and the operating pressure is about 100 times smaller. Different xenon–neon gas mixtures have been investigated. Optical filters have been used to measure infrared emission from xenon excited states 823.1 and 828.0 nm, and visible emission from neon at 640.2 nm. The measurements show that the neon visible emission occurs only above the cathode while xenon infrared emission occurs above both cathode and anode. Standing striations can be observed above the anode. The strong xenon emission above anode indicates that this region is more efficient than the cathode region in terms of ultraviolet production. The measurements are in excellent qualitative agreement with similar measurements performed in real PDP cells. However the velocity of plasma spreading above the cathode in the macrocell is significantly larger than in a real PDP cell. The interpretation of this discrepancy is given in a companion paper (part II) [J. Appl. Phys. 91, 1000 (2002)] where the experimental results are compared with results from a fluid model of the plasma.

The polarization state of an ultrafast laser is dynamically controlled using two Spatial Light Modulators and additional waveplates. Consequently, four states of polarization, linear horizontal and vertical, radial and azimuthal, all with a ring intensity distribution, were dynamically switched at a frequency ν = 12.5 Hz while synchronized with a motion control system. This technique, demonstrated here for the first time, enables a remarkable level of real-time control of the properties of light waves and applied to real-time surface patterning, shows that highly controlled nanostructuring is possible. Laser ablation of Induced Periodic Surface Structures is used to directly verify the state of polarization at the focal plane.

Wellbore deviations, encountered during oil well drilling operations in rocks exhibiting laminations or foliations, can be attributed to rock-bit interaction. Numerical modeling of the rock-bit interaction process in laminated formation has been performed using a finite element approach. A finite element program was developed with the assumption of plane strain. Anisotropic elements, dynamic, loading, progressive failure, and variable stiffness were used to represent the actual penetration process. The Hoek and Brown failure criterion was used in the failure analysis. An iteration method, using an incremental approach, has been applied for the continuous tooth penetration process where displacements, axial loads, strength and stiffness of elements are modified after each iteration. The program provides quantitative information on stress, displacement, and rock failure for each iteration. Furthermore, deviation due to laminated formation can be inferred and the effects of changing bit geometry can be assessed. The model also shows good quantitative agreement with laboratory wedge indentation tests.

A large number of fatigue cracks and fractures of test specimens and components of various engineering alloys were investigated by means of the fractographic technique. In particular, critical experiments were performed on the observation of natural profiles of fracture plateaus and mating fracture surfaces using the scanning electron microscope. It was found that the profile of a fatigue crack appears to be a tunnel with numerous steps. In consequence, the striations on the matching surfaces are basically in register other than any kinds of symmetrical configurations such as peaks to peaks and valleys to valleys. Furthermore, the appearance of them on one surface is usually more regular and distinct than that on the matching surface due to their greater slip length and, sometimes, slipband notches or cracks. The process of fatigue crack growth is just like alternatively walking up or down the steps of a path in different areas or grains. A more general and practical model schematically illustrating the mechanism of fatigue crack growth and striation formation, which is one of the most fundamental questions on fatigue, is proposed. According to this model, the process of fatigue crack growth under a loading cycle includes four steps: (i) crack-tip opening; (ii) shear crack growth in a very short distance by single system slip decohesion; (iii) normal crack growth by alternative conjugate slip decohesion; and (iv) crack-tip closing, resharpening and, sometimes, inducing one or two slipband notches or cracks at the very tip. It differs markedly from the previous models which, in general, describe the crack advancing under conditions of symmetric deformation at the crack tip and growing straight along the crack plane in a loading cycle. Based on the present model, the markings on the fracture surfaces and phenomena associated with the process of crack growth, such as the secondary shear cracks accompanying by the striations, the slipbands between striations, and the simultaneous growth of branching cracks, can properly be explained.

Proper and rapid identification of malfunctions is of premier importance for the safe operation of Nuclear Power Plants (NPP). Many monitoring or/and diagnosis methodologies based on artificial and computational intelligence have been proposed to aid operator to understand system problems, perform trouble-shooting action and reduce human error under serious pressure. However, because no single method is adequate to handle all requirements for diagnostic system, hybrid approaches where different methods work in conjunction to solve parts of the problem interest researchers greatly. In this study, Multilevel Flow Models (MFM) and Artificial Neural Network (ANN) are proposed and employed to develop a fault diagnosis system with the intention of improving the success rate of recognition on the one hand, and improving the understandability of diagnostic process and results on the other hand. Several simulation cases were conducted for evaluating the performance of the proposed diagnosis system. The simulation results validated the effectiveness of the proposed hybrid approach.

Study Design. Fifty-five human thoracolumbar vertebrae were randomly fatigue loaded and analyzed. Objectives. The purpose of this study was to explore the relationship between fatigue loading, trabecular microfracture, and energy absorption to fracture in human cadaveric thoracolumbar vertebrae. Background. Although trabecular microfractures are found in vivo and have been produced by fatigue loading in vitro, the effect of the level of physiologic fatigue loading on microfracture and energy absorption has not been investigated. Methods. Fifty-five human thoracolumbar vertebrae (T11-L4) were randomly divided into 5 groups: 1) control (no loading, n = 6); 2) axial compression to yield (n = 7); and 3-5) 20,000 cycles of fatigue loading at 2 Hz (each n = 14). The level of fatigue loading was determined as a proportion of the yield load of Group 2 as follows: 10% (Group 3), 20% (Group 4), and 30% (Group 5). Half of the specimens in groups 3 to 5 were used for radiographic and histomorphometric analysis to determine microfracture density and distribution, whereas the other half were tested to determine the energy absorption to yield failure. Results. No radiographic evidence of gross fracture was found in any of the groups following fatigue loading. A mean 7.5% increase in stiffness was found in specimens subject to cyclic loading at 10% of yield stress (Group 3). Fatigue at 20% (Group 4) and 30% of yield stress (Group 5) caused significantly higher (P < 0.05) increases in mean stiffness of 23.6% and 24.2%, respectively. Microfracture density increased from 0.46/mm 2 in Group 3 to 0.66/mm 2 in Group 4 and 0.94/mm 2 in Group 5 (P < 0.05). The energy absorbed to failure decreased from 21.9 J in Group 3 to 18.1 J and 19.6 J in Groups 4 and 5, respectively (P < 0.05). Conclusions. Fatigue loading at physiologic levels produced microfractures that are not detectable by radiography. Increased fatigue load results in an increase in microfracture density and decrease energy absorbed to fracture, indicating a reduced resistance to further fatigue loading.