Can a 3 months treatment with oral Desogestrel prior to insertion of the etonogestrel-releasing contraceptive implant improve continuation rate at 1 year? A randomized trial.

Objective: To evaluate if daily oral 75 µg of Desogestrel (DSG) for 3 months prior to the insertion of etonogestrel-releasing contraceptive implant (ENG-IMPLANT) might help reduce its premature discontinuation.

Results: A total of 66 women were randomized in the ENG-IMPLANT group (26) and in the DSG + ENG-IMPLANT group (40), respectively, in the Geneva University Hospitals and Basel University Hospital, from August 15th, 2016 through September 30th, 2019. In the DSG + ENG-IMPLANT group, patients were given a 3 months' supply of 75 µg of DSG before the insertion of the ENG-IMPLANT.

Argonaute5 and its associated small RNAs modulate the transcriptional response during the rhizobia- symbiosis.

Both plant- and rhizobia-derived small RNAs play an essential role in regulating the root nodule symbiosis in legumes. Small RNAs, in association with Argonaute proteins, tune the expression of genes participating in nodule development and rhizobial infection. However, the role of Argonaute proteins in this symbiosis has been overlooked.

AAPM MEDICAL PHYSICS PRACTICE GUIDELINE 2.b.: Commissioning and quality assurance of X-ray-based image-guided radiotherapy systems.

The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States.

Glutathione Directly Intercepts DNA Radicals To Inhibit Oxidative DNA-Protein Cross-Linking Induced by the One-Electron Oxidation of Guanine.

Oxidative DNA damage can lead to cancer, and as enzymatic DNA repair systems become compromised during the aging process, the role of exogenous antioxidants becomes more critical. Here, we examined whether such non-enzymatic DNA repair can be effected by the common cellular antioxidant glutathione, investigating both permanent DNA damage products and the guanine radical intermediates that form them, using the flash-quench technique to carry out the one-electron oxidation of guanine. In gel-shift assays, the presence of reduced glutathione at physiological (millimolar) concentrations strongly inhibits oxidative DNA-protein cross-linking.

Photoprocessing of large PAH cations.

In cosmic environments, polycyclic aromatic hydrocarbons (PAHs) strongly interact with vacuum ultraviolet (VUV) photons emitted by young stars. Trapped PAH cations ranging in size from 30 to 48 carbon atoms were irradiated by tunable synchrotron light (DESIRS beamline at SOLEIL). Their ionization and dissociation cross sections were determined and compared with TD-DFT computed photoabsorption cross sections.

Investigating the importance of edge-structure in the loss of H/H of PAH cations: the case of dibenzopyrene isomers.

We present a detailed study of the main dehydrogenation processes of two dibenzopyrene cation (CH) isomers, namely dibenzo(a,e)pyrene (AE) and dibenzo(a,l)pyrene (AL). First, action spectroscopy under VUV photons was performed using synchrotron radiation in the 8-20 eV range. We observed lower dissociation thresholds for the non-planar molecule (AL) than for the planar one (AE) for the main dissociation pathways: H and 2H/H loss.

Charge Density Influence on Enthalpy of Formation of Uranyl Peroxide Cage Cluster Salts.

More than 60 unique uranyl peroxide cage clusters have been reported that contain as many as 124 uranyl ions and that have overall diameters extending to 4 nm. They self-assemble in water under ambient conditions, are models for understanding structure-size-property relations as well as testing computational models for actinides, and have potential applications in nuclear fuel cycles. High-temperature drop solution calorimetry has been used to derive the enthalpies of formation of the salts of seven topologically diverse uranyl peroxide cage clusters containing from 22 to 28 uranyl ions that are bridged by various combinations of peroxide, pyrophosphate, and phosphite.

Automated identification and reduction of artifacts in cine four-dimensional computed tomography (4DCT) images using respiratory motion model.

Purpose: Four-dimensional computed tomography (4DCT) images are often marred by artifacts that substantially degrade image quality and confound image interpretation. Human observation remains the standard method of 4DCT artifact evaluation, which is time-consuming and subjective. We develop a method to automatically identify and reduce artifacts in cine 4DCT images.

Lattice Dynamics of the Rhombohedral Polymorphs of CaSi.

The structures of two trigonal-rhombohedral CaSi polymorphs (space group R3̅m) were studied by X-ray diffraction and polarized Raman scattering spectroscopy. Raman-active even-parity vibrational modes of A and E are unambiguously identified and assigned to the specific lattice eigenmodes. Experimental data are found to be in very good agreement with those predicted by density functional theory lattice dynamics calculations.

VUV photo-processing of PAH cations: quantitative study on the ionization versus fragmentation processes.

Interstellar polycyclic aromatic hydrocarbons (PAHs) are strongly affected by the absorption of vacuum ultraviolet (VUV) photons in the interstellar medium (ISM), yet the branching ratio between ionization and fragmentation is poorly studied. This is crucial for the stability and charge state of PAHs in the ISM in different environments, affecting in turn the chemistry, the energy balance, and the contribution of PAHs to the extinction and emission curves. We studied the interaction of PAH cations with VUV photons in the 7 - 20 eV range from the synchrotron SOLEIL beamline, DESIRS.

Evaluation of 4D CT acquisition methods designed to reduce artifacts.

Four-dimensional computed tomography (4D CT) is used to account for respiratory motion in radiation treatment planning, but artifacts resulting from the acquisition and postprocessing limit its accuracy. We investigated the efficacy of three experimental 4D CT acquisition methods to reduce artifacts in a prospective institutional review board approved study. Eighteen thoracic patients scheduled to undergo radiation therapy received standard clinical 4D CT scans followed by each of the alternative 4D CT acquisitions: 1) data oversampling, 2) beam gating with breathing irregularities, and 3) rescanning the clinical acquisition acquired during irregular breathing.

Assessment of a quantitative metric for 4D CT artifact evaluation by observer consensus.

The benefits of four-dimensional computed tomography (4D CT) are limited by the presence of artifacts that remain difficult to quantify. A correlation-based metric previously proposed for ciné 4D CT artifact identification was further validated as an independent artifact evaluator by using a novel qualitative assessment featuring a group of observers reaching a consensus decision on artifact location and magnitude. The consensus group evaluated ten ciné 4D CT scans for artifacts over each breathing phase of coronal lung views assuming one artifact per couch location.

Pre-radiotherapy FDG PET predicts radiation pneumonitis in lung cancer.

Background: A retrospective analysis is performed to determine if pre-treatment [18 F]-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) image derived parameters can predict radiation pneumonitis (RP) clinical symptoms in lung cancer patients.

Methods And Materials: We retrospectively studied 100 non-small cell lung cancer (NSCLC) patients who underwent FDG PET/CT imaging before initiation of radiotherapy (RT). Pneumonitis symptoms were evaluated using the Common Terminology Criteria for Adverse Events version 4.