Changing impacts of Alaska-Aleutian subduction zone tsunamis in California under future sea-level rise.

The amplification of coastal hazards such as distant-source tsunamis under future relative sea-level rise (RSLR) is poorly constrained. In southern California, the Alaska-Aleutian subduction zone has been identified as an earthquake source region of particular concern for a worst-case scenario distant-source tsunami. Here, we explore how RSLR over the next century will influence future maximum nearshore tsunami heights (MNTH) at the Ports of Los Angeles and Long Beach. Earthquake and tsunami modeling combined with local probabilistic RSLR projections show the increased potential for more frequent, relatively low magnitude earthquakes to produce distant-source tsunamis that exceed historically observed MNTH. By 2100, under RSLR projections for a high-emissions representative concentration pathway (RCP8.5), the earthquake magnitude required to produce >1 m MNTH falls from ~Mw9.1 (required today) to Mw8.0, a magnitude that is ~6.7 times more frequent along the Alaska-Aleutian subduction zone.

Back to full interseismic plate locking decades after the giant 1960 Chile earthquake.

Great megathrust earthquakes arise from the sudden release of energy accumulated during centuries of interseismic plate convergence. The moment deficit (energy available for future earthquakes) is commonly inferred by integrating the rate of interseismic plate locking over the time since the previous great earthquake. But accurate integration requires knowledge of how interseismic plate locking changes decades after earthquakes, measurements not available for most great earthquakes. Here we reconstruct the post-earthquake history of plate locking at Guafo Island, above the seismogenic zone of the giant 1960 (Mw = 9.5) Chile earthquake, through forward modeling of land-level changes inferred from aerial imagery (since 1974) and measured by GPS (since 1994). We find that interseismic locking increased to ~70% in the decade following the 1960 earthquake and then gradually to 100% by 2005. Our findings illustrate the transient evolution of plate locking in Chile, and suggest a similarly complex evolution elsewhere, with implications for the time- and magnitude-dependent probability of future events.

The Cell-CT 3-dimensional cell imaging technology platform enables the detection of lung cancer using the noninvasive LuCED sputum test.

The war against cancer has yielded important advances in the early diagnosis and treatment of certain cancer types, but the poor detection rate and 5-year survival rate for lung cancer has changed little over the past 40 years. Early detection through emerging lung cancer screening programs promise the most reliable means of improving mortality. Sputum cytology has been tried without success because sputum contains few malignant cells that are difficult for cytologists to detect. However, research has shown that sputum contains diagnostic malignant cells and could serve as a means of lung cancer detection if those cells could be detected and correctly characterized. Recently, the National Lung Screening Trial reported that screening using 3 consecutive low-dose x-ray computed tomography scans provides a 20% reduction in lung cancer mortality compared with chest x-ray. However, this reduction in mortality comes with an unacceptable false-positive rate that increases patient risks and the overall cost of lung cancer screening. The LuCED test for detection of early lung cancer is reviewed in the current article. LuCED is based on patient sputum that is enriched for bronchial epithelial cells. The enriched sample is then processed on the Cell-CT, which images cells in 3 dimensions with submicron resolution. Algorithms are applied to the 3-dimensional cell images to extract morphometric features that drive a classifier to identify cells that have abnormal characteristics. The final status of these candidate abnormal cells is established by the pathologist's manual review. LuCED promotes accurate cell classification that could enable the cost-effective detection of lung cancer.

Automated 3-dimensional morphologic analysis of sputum specimens for lung cancer detection: Performance characteristics support use in lung cancer screening.

BACKGROUND: The LuCED Lung Test comprises an automated 3-dimensional morphologic analysis of epithelial cells in sputum. For each cell, 594 morphology-based features are measured to drive algorithmic classifiers that quantitatively assess whether neoplastic cells are present. The current interim clinical study involves sputum samples from patients with known benign and malignant outcomes to assess the feasibility of LuCED as an adjunctive test after suspicious low-dose computed tomography (LDCT) results or as an independent screening test for lung cancer. METHODS: Sputum samples were fixed, enriched for epithelial cells, and analyzed with a 3-dimensional cell scanner called Cell-CT. Candidate abnormal cells were identified by the classifiers for manual review. The sensitivity, specificity, and negative and positive predictive values were calculated for the detection of neoplastic cases. RESULTS: A total of 91 sputum samples from patients with confirmed lung cancer (49 patients) and patients with no known malignancy (42 patients) were evaluated. After cytology review, sensitivity in the positive group was 91.8%, and specificity was 95.2%. Specificity was not 100% because there were 2 cases in which abnormal cells were identified by the Cell-CT that were confirmed as such at the time of manual cytology review. However, at the time of last follow-up, malignancy had not been detected in these 2 cases. Modeling in a population with a 1% prevalence of lung cancer, the positive and negative predictive values would be 95.4% and 99.9%, respectively. CONCLUSIONS: LuCED testing is highly sensitive and specific for the detection of lung cancer and has potential value as an adjunctive test after suspicious LDCT findings or as a primary screening test in which LuCED-positive cases would be triaged to diagnostic CT. Further prospective studies currently are underway to evaluate its full usefulness.

An alternative approach to account for patient organ doses from imaging guidance procedures.

PURPOSE: To investigate the feasibility of an alternative method of accounting for additional organ doses resulting from image guidance procedures during patient treatment planning through tabulated values based on scan protocol and scan site. METHODS AND MATERIALS: Patient-specific imaging dose to 30 patients resulting from Varian OBI kV-CBCT scans using the Standard Head (17 patients), Low-dose Thorax (8 patients), and Pelvic (5 patients) scan protocols were retrospectively calculated using Monte Carlo methods. Dose dependence on scan location and patient geometry was explored. Patient organ doses were analyzed by using dose-volume histograms and expressed by the mean, minimum dose delivered to 50% of the organ volume, D50. The reported doses are dose-to-medium instead of dose-to-water. RESULTS: The organ doses from all patient-specific calculations show predictable and limited ranges across patients. For brain isocenters using Standard Head Scans: Bone: 0.7-1.1 cGy, Brain: 0.2-0.3 cGy, Brainstem: 0.2-0.3 cGy, Skin: 0.3-0.4 cGy, Eye: 0.03-0.3 cGy. For head and neck patients using the Standard Head Scan: Bone: 0.3-0.6 cGy, Parotids: 0.3-0.4 cGy, Spinal Cord: 0.15-0.25 cGy, Thyroid: 0.1-0.25 cGy, Skin: 0.2-0.3 cGy, Trachea-Esophagus: 0.1-0.2 cGy. For chest using Thorax Scans: Bone: 1.1-1.8 cGy, Soft tissue organs (Bowel, Lung, Heart, Kidney, Esophagus, and Spinal Cord): 0.3-0.6 cGy. For abdominal site using Pelvic Scans: Bone: 3.2-4.2 cGy. Soft tissue organs (Bladder, Bowel, Rectum, Prostate, and Skin) D50s fell between 1.2 and 2.2 cGy. Femoral Heads: 2.5-3.4 cGy. CONCLUSIONS: It is adequate to estimate and account for organ dose by using tabulated values based on scan procedure and site because organ doses from imaging procedures are only modestly dependent upon scan location and body size. Considering the dose variation and magnitude of dose from each scan protocol in comparison to therapeutic doses, this approach provides a simple alternative to account for additional imaging guidance doses during patient treatment planning. Clinicians can use these tabulated values to make informed decisions in selecting the appropriate imaging procedures and imaging frequency during radiotherapy treatment.

Resolution improvement in optical projection tomography by the focal scanning method.

Optical projection tomography (OPT) requires the depth of field (DOF) of the lens to cover at least half of the sample. There is a trade-off between obtaining high resolution with a high-NA lens and obtaining large DOF with a low-NA lens. The DOF of a high-NA objective lens can be extended by scanning its focal plane through the sample. We call this extended DOF image a "pseudoprojection." Images reconstructed from these pseudoprojections have isometric resolution, which can be the same as the lateral resolution of the high-NA objective. The focal scanning method produces an over 10× improvement in OPT resolution.

Dual-mode optical projection tomography microscope using gold nanorods and hematoxylin-stained cancer cells.

An optical projection tomography microscope (OPTM) can improve axial resolution by viewing a sample from different perspectives. Here, we report a dual-mode OPTM that can generate 3D images of single cancer cells in both absorption mode and polarization mode. Cancer cells were labeled with hematoxylin for absorption imaging and nanorods for polarization imaging. Absorption images can provide morphologic information, and polarization images can provide molecular information. The combination of molecular detection and 3D cytological cell analysis may help with early cancer diagnosis.

Chemical composition of enamel surface as a predictor of in-vitro shear bond strength.

INTRODUCTION: Orthodontic bond failure varies between patients. It has been speculated that the chemical composition of the enamel surface might play a role in the variations in bond failure. METHODS: X-ray photoelectron spectroscopy was used in analyzing the surface chemical composition of 49 pairs of maxillary right and left first premolars from patients requiring extractions as part of the orthodontic treatment. After x-ray photoelectron spectroscopy analysis, 49 enamel samples were randomly selected for an in-vitro shear bonding study with a materials testing system, Synergie 400 machine (MTS Systems, Eden Prairie, Minn). RESULTS: The in-vitro shear bond strength was found to have a mean of 6.93 +/- 2.71 MPa. Twelve elements were detected; the major ones were calcium, phosphorus, oxygen, nitrogen, and carbon. Regression analysis with the 12 elements explained 33.3% of the variations in bond strength. However, the contribution was not significant (P = 0.170). CONCLUSIONS: The chemical composition of the buccal surface of maxillary first premolars was not significant in predicting in-vitro mean shear bond strength. Other factors are likely to be important contributors to the large variations frequently seen in bond strength studies.

Premalignant and malignant cells in sputum from lung cancer patients.

BACKGROUND: The objective of this study was to assess the frequency of premalignant and malignant cells in sputum from patients with lung cancer and to measure the dependence of these cells on cancer stage, histologic type, tumor size, and tumor location. METHODS: This analysis included 444 patients with lung cancer. First, all patients were asked to produce sputum spontaneously; then, they underwent sputum induction. Slide preparations of the sputa were screened for the presence of abnormal cells. RESULTS: Of all patients with lung cancer who had produced adequate specimens, 74.6% had sputum that was positive for premalignant or worse cells, whereas 48.7% had sputum that was positive for malignant cells alone. Surprisingly, the presence of premalignant or worse cells in sputum depended only moderately on disease stage (82.9% of stage IV cancers vs 65.9% of stage I cancers), tumor size (78.6% of tumors >2 cm vs 64.7% of tumors

Dual-modal three-dimensional imaging of single cells with isometric high resolution using an optical projection tomography microscope.

The practice of clinical cytology relies on bright-field microscopy using absorption dyes like hematoxylin and eosin in the transmission mode, while the practice of research microscopy relies on fluorescence microscopy in the epi-illumination mode. The optical projection tomography microscope is an optical microscope that can generate 3-D images of single cells with isometric high resolution both in absorption and fluorescence mode. Although the depth of field of the microscope objective is in the submicron range, it can be extended by scanning the objective's focal plane. The extended depth of field image is similar to a projection in a conventional x-ray computed tomography. Cells suspended in optical gel flow through a custom-designed microcapillary. Multiple pseudoprojection images are taken by rotating the microcapillary. After these pseudoprojection images are further aligned, computed tomography methods are applied to create 3-D reconstruction. 3-D reconstructed images of single cells are shown in both absorption and fluorescence mode. Fluorescence spatial resolution is measured at 0.35 microm in both axial and lateral dimensions. Since fluorescence and absorption images are taken in two different rotations, mechanical error may cause misalignment of 3-D images. This mechanical error is estimated to be within the resolution of the system.

One-dimensional neutron imager for the Sandia Z facility.

A multiinstitution collaboration is developing a neutron imaging system for the Sandia Z facility. The initial system design is for slit aperture imaging system capable of obtaining a one-dimensional image of a 2.45 MeV source producing 5x10(12) neutrons with a resolution of 320 microm along the axial dimension of the plasma, but the design being developed can be modified for two-dimensional imaging and imaging of DT neutrons with other resolutions. This system will allow us to understand the spatial production of neutrons in the plasmas produced at the Z facility.

Simultaneous 3D imaging of morphology and nanoparticle distribution in single cells with the Cell-CT technology.

The Cell-CT is an optical projection tomography microscope (OPTM) developed for high resolution 3D imaging of single cells based on absorption stains and brightfield microscopy. In this study we demonstrate the use of the Cell-CT in multi-color mode for simultaneous imaging of cellular 3D morphology and the 3D distribution of nanoparticle clusters in the cytoplasm. The ability to image cellular processes in relation to cellular compartments with a non-fluorescence 3D technology opens new perspectives for molecular research.

Argon laser vs conventional visible light-cured orthodontic bracket bonding: an in-vivo and in-vitro study.

INTRODUCTION: Many advantages of argon lasers have been reported, including high-speed orthodontic adhesive curing and less enamel demineralization. The purpose of this study was to compare bond strengths after curing with the argon laser (10 seconds) and the conventional curing light (40 seconds) in vivo and in vitro. METHODS: Four premolars from each of 23 volunteers were randomly assigned to either the argon laser group or the conventional light group for the in-vivo study. Shear bond strengths were measured after 14 days with custom-designed debonding pliers. In-vitro bond strengths were measured by using 4 premolars from each of 25 volunteers. Shear bond strength was measured after 14 days of thermocycling with the same protocol as the in-vivo study. Adhesive remnant index scores (ARI) were determined. RESULTS: No significant differences were found in bond strengths according to curing method, dental arch, or sex. In-vivo results were significantly lower (P < .05) than in-vitro results. A significant (P < .05) difference in ARI scores between the curing methods was determined; no significant correlation between mean bond strengths and ARI scores was determined. CONCLUSIONS: Bond strength for argon laser curing is comparable to conventional light curing and is sufficient for clinical applications. Although the argon laser left more adhesive on the tooth surfaces on debonding, there was no increase in enamel surface fractures.

Examination of spinel and nonspinel structural models for gamma-Al2O3 by DFT and rietveld refinement simulations.

Despite the widespread use of gamma-Al2O3, there is still considerable disagreement over the nature of its structure due to both its poor crystallinity and differing preparation techniques during experimentation. Using density-functional theory (DFT) calculations and Rietveld simulations and refinement, the structure of three spinel-related models and a recently proposed nonspinel model were studied in reference to synchrotron X-ray powder diffraction (SXPD) patterns. The spinel-based structural models represent the structural features of gamma-Al2O3 better than the nonspinel model. The major failure of the nonspinel model is that the model cannot reproduce the SXPD reflection originating from tetrahedral aluminum. The Rietveld-refined spinel model can accurately reproduce the lattice parameters and other structural features of gamma-Al2O3, and it can generate a consistent diffraction peak at 2theta which lies between the splitting peaks of the experimental pattern that are originated from the disordered tetrahedral aluminum cations.

Density functional theory study of pyrrole adsorption on Mo(110).

The objective of the present study is to identify possible adsorption configurations of pyrrole on Mo(110) using density functional theory (DFT) calculations. Several adsorption configurations were studied including pyrrole and pyrrolyl adsorption as parallel, perpendicular, and tilted adsorption modes relative to the Mo(110) surface plane. Based on the DFT calculations, pyrrole is suggested to adsorb in a parallel mode with respect to the Mo(110) surface through its pi-orbital as mu3,eta(5)-Pyr-0 degrees with an adsorption energy of -28.7 to -31.5 kcal mol(-1). The possibility of a coexisting mode where pyrrole adsorbs on the surface with a slightly tilted molecular plane as mu3,eta(4)(N,C2,C3,C4)-Pyr-5 degrees is also likely to occur, particularly at higher pyrrole coverages. The slightly tilted configuration is suggested to arise from the lateral interactions of adsorbed pyrrole on Mo(110), and not the result of a phase transformation on the surface since this requires a relatively high activation energy as indicated by additional linear synchronous transit (LST)/quadratic synchronous transit (QST) calculations. Both adsorption geometries bond to three surface Mo atoms, and Mo(110) did not promote hydrogen abstraction. Pyrrolyl adsorption on Mo(110) is energetically possible, but unlikely to occur because gas-phase hydrogen has not been previously experimentally observed as a pyrrole decomposition product on Mo(110).

Three-dimensional imaging of single isolated cell nuclei using optical projection tomography.

A method is presented for imaging single isolated cell nuclei in 3D, employing computed tomographic image reconstruction. The system uses a scanning objective lens to create an extended depth-of-field (DOF) image similar to a projection or shadowgram. A microfabricated inverted v-groove allows a microcapillary tube to be rotated with sub-micron precision, and refractive index matching within 0.02 both inside and outside the tube keeps optical distortion low. Cells or bare cell nuclei are injected into the tube and imaged in 250 angular increments from 0 to 180 degrees to collect 250 extended DOF images. After these images are further aligned, the filtered backprojection algorithm is applied to compute the 3D image. To estimate the cutoff spatial frequency in the projection image, a spatial frequency ratio function is calculated by comparing the extended depth-of-field image of a typical cell nucleus to the fixed focus image. To assess loss of resolution from fixed focus image to extended DOF image to 3D reconstructed image, the 10-90% rise distance is measured for a dyed microsphere. The resolution is found to be 0.9 microm for both extended DOF images and 3D reconstructed images. Surface and translucent volume renderings and cross-sectional slices of the 3D images are shown of a stained nucleus from fibroblast and cancer cell cultures with added color histogram mapping to highlight 3D chromatin structure.