Optimal set of grid size and angular increment for practical dose calculation using the dynamic conformal arc technique: a systematic evaluation of the dosimetric effects in lung stereotactic body radiation therapy

Purpose To recommend the optimal plan parameter set of grid size and angular increment for dose calculations in treatment planning for lung stereotactic body radiation therapy (SBRT) using dynamic conformal arc therapy (DCAT) considering both accuracy and computational efficiency. Materials and methods Dose variations with varying grid sizes (2, 3, and 4 mm) and angular increments (2°, 4°, 6°, and 10°) were analyzed in a thorax phantom for 3 spherical target volumes and in 9 patient cases. A 2-mm grid size and 2° angular increment are assumed sufficient to serve as reference values. The dosimetric effect was evaluated using dose–volume histograms, monitor units (MUs), and dose to organs at risk (OARs) for a definite volume corresponding to the dose–volume constraint in lung SBRT. The times required for dose calculations using each parameter set were compared for clinical practicality. Results Larger grid sizes caused a dose increase to the structures and required higher MUs to achieve the target coverage. The discrete beam arrangements at each angular increment led to over- and under-estimated OARs doses due to the undulating dose distribution. When a 2° angular increment was used in both studies, a 4-mm grid size changed the dose variation by up to 3–4% (50 cGy) for the heart and the spinal cord, while a 3-mm grid size produced a dose difference of \u3c1% (12 cGy) in all tested OARs. When a 3-mm grid size was employed, angular increments of 6° and 10° caused maximum dose variations of 3% (23 cGy) and 10% (61 cGy) in the spinal cord, respectively, while a 4° increment resulted in a dose difference of \u3c1% (8 cGy) in all cases except for that of one patient. The 3-mm grid size and 4° angular increment enabled a 78% savings in computation time without making any critical sacrifices to dose accuracy. Conclusions A parameter set with a 3-mm grid size and a 4° angular increment is found to be appropriate for predicting patient dose distributions with a dose difference below 1% while reducing the computation time by more than half for lung SBRT using DCAT

Production of Transgenic Cloned Miniature Pigs with Membrane-bound Human Fas Ligand (FasL) by Somatic Cell Nuclear Transfer

Cell-mediated xenograft rejection, including NK cells and CD8+ CTL, is a major obstacle in successful pig-to-human xenotransplantation. Human CD8+ CTL and NK cells display high cytotoxicity for pig cells, mediated at least in part by the Fas/FasL pathway. To prevent cell-mediated xenocytotoxicity, a membrane-bound form of human FasL (mFasL) was generated as an inhibitor for CTL and NK cell cytotoxicity that could not be cleaved by metalloproteinase to produce putative soluble FasL. We produced two healthy transgenic pigs harboring the mFasL gene via somatic cell nuclear transfer (SCNT). In a cytotoxicity assay using transgenic clonal cell lines and transgenic pig ear cells, the rate of CD8+ CTL-mediated cytotoxicity was significantly reduced in transgenic pig's ear cells compared with that in normal minipig fetal fibroblasts. Our data indicate that grafts of transgenic pigs expressing membrane-bound human FasL control the cellular immune response to xenografts, creating a window of opportunity to facilitate xenograft survival

In Vivo Analysis of Three-Dimensional Dynamic Scapular Dyskinesis in Scapular or Clavicular Fractures

The three-dimensional (3D) kinematics of the scapula were analyzed in vivo in 10 patients with scapular and 10 patients with clavicular fracture. Both the injured shoulder and normal contralateral shoulder were evaluated by computed tomography in the neutral and fully elevated positions. 3D rotational and translational movements of the scapula relative to the thorax during arm elevation were analyzed. A computer simulation program was used to compare rotational elevation/depression in the coronal plane, anterior/posterior tilting in the sagittal plane and protraction/retraction in the axial plane between the normal and affected sides. Anterior/posterior translational movement along the X-axis, upward/downward movement along the Y-axis, and lateral/medial movement along the Z-axis in the Euler space during forward elevation were also compared. In scapular fracture, rotational elevation of the scapula decreased in the coronal plane and posterior tilting of the scapula increased in the sagittal plane. Anterior and superior translation were higher in scapular fracture than in the corresponding normal sides. However, no significant abnormal rotational and translational kinematic changes were observed during elevation in clavicular fracture. In vivo 3D computerized motion analysis was useful for evaluating scapular dyskinesis. Scapular fracture can cause scapular dyskinesis, but not all clavicular fractures alter scapular motion biomechanics

Digital Workflow for Retrofitting a Surveyed Crown Using a Removable Partial Denture as an Antagonist

Digital workflow expedites the procedure of retrofitting a surveyed crown against an existing removable partial denture (RPD). This article describes a simple and straightforward technique of digital workflow where an existing RPD is scanned as an antagonist to design the rest seat, guide plane, and height of contour of a surveyed crown.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156192/2/jopr13187_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156192/1/jopr13187.pd

Evolution of optical phonons in CdS nanowires, nanobelts, and nanosheets

We report Raman scattering from single and ensemble CdS nanowires, nanobelts, and nanosheets. The Raman spectra of nanobelts and nanosheets are notably different from those of nanowires, exhibiting a strong enhancement of the multiphonon response. Moreover, the first-order longitudinal optical (LO) phonon energy systematically increases with increasing lateral size from nanowires to nanobelts, and to nanosheets. These results suggest that the optical phonons in the CdS nanostructures are influenced by strain, crystallinity, and exciton-LO phonon coupling.open342

Cell-free synthesis of functional phospholipase A1 from Serratia sp.

Additional file 1: Figure S1 Gas chromatography analysis of sesame oil incubated with cell-free synthesized PLA1

Screening models using multiple markers for early detection of late-onset preeclampsia in low-risk pregnancy

BACKGROUND: Our primary objective was to establish a cutoff value for the soluble fms-like tyrosine kinase 1(sFlt-1)/placental growth factor (PlGF) ratio measured using the Elecsys assay to predict late-onset preeclampsia in low-risk pregnancies. Our secondary objective was to evaluate the ability of combination models using Elecsys data, second trimester uterine artery (UtA) Doppler ultrasonography measurements, and the serum fetoplacental protein levels used for Down’s syndrome screening, to predict preeclampsia. METHODS: This prospective cohort study included 262 pregnant women with a low risk of preeclampsia. Plasma levels of pregnancy-associated plasma protein-A (PAPP-A) and serum levels of alpha-fetoprotein, unconjugated estriol, human chorionic gonadotropin, and inhibin-A were measured, and sFlt-1/PlGF ratios were calculated. All women underwent UtA Doppler ultrasonography at 20 to 24 weeks of gestation. RESULTS: Eight of the 262 women (3.0%) developed late-onset preeclampsia. Receiver operating characteristic curve analysis showed that the third trimester sFlt-1/PlGF ratio yielded the best detection rate (DR) for preeclampsia at a fixed false-positive rate (FPR) of 10%, followed by the second trimester sFlt-1/PlGF ratio, sFlt-1 level, and PlGF level. Binary logistic regression analysis was used to determine the five best combination models for early detection of late-onset preeclampsia. The combination of the PAPP-A level and the second trimester sFlt-1/PlGF ratio yielded a DR of 87.5% at a fixed FPR of 5%, the combination of second and third trimester sFlt-1/PlGF ratios yielded a DR of 87.5% at a fixed FPR of 10%, the combination of body mass index and the second trimester sFlt-1 level yielded a DR of 87.5% at a fixed FPR of 10%, the combination of the PAPP-A and inhibin-A levels yielded a DR of 50% at a fixed FPR of 10%, and the combination of the PAPP-A level and the third trimester sFlt-1/PlGF ratio yielded a DR of 62.5% at a fixed FPR of 10%. CONCLUSIONS: The combination of the PAPP-A level and the second trimester sFlt-1/PlGF ratio, and the combination of the second trimester sFlt-1 level with body mass index, were better predictors of late-onset preeclampsia than any individual marker