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We report first-principles total-energy density-functional theory electronic structure calculations for the neutral and charge states of H intrinsic ͑Frenkel pair͒ and extrinsic ͑H vacancy or interstitial͒ point defects in KH 2 PO 4 . The relaxed atomic structures, the formation energy, the ionization energy, and electron and hole affinities for the various defects have been calculated. For the Frenkel pair, the additional hole leads to a decrease of the OuO bond length between the two O atoms next to the H vacancy, while the effect of the additional electron is small. For the H vacancy, the added hole is trapped and shared by the two O atoms adjacent to the vacancy, reducing dramatically the OuO bond length, thus forming a molecular-type polaron. We find that the positively charged H vacancy introduces states in the gap, in contrast with its neutral state, confirming the experimental suggestion that it is a relevant absorbing center. The negatively charged H vacancy leads to an increase of the two O atoms close to the H vacancy, and does not induce states in the gap. The H interstitial does not interact with the host atoms in the neutral state. However, the addition of an electron leads to the ejection of a H host atom and the subsequent formation of a H 2 interstitial molecule and a H vacancy, in agreement with experimental suggestions. In the positively charged state the H interstitial binds to its nearest-neighbor O atom forming a hydroxyl bond. The H interstitial in both positive and negative charge states induces no defect states in the band gap, in contrast with its neutral state. The calculations provide insights into the role of the charged and neutral defects on the transient optical absorption under irradiation by high-intensity laser beam.

Background Surgery is becoming more practical and effective than conservative treatment in improving the poor outcomes of patients with breast cancer liver metastasis (BCLM). However, there is no generally acknowledged set of standards for identifying BCLM candidates who will benefit from surgery. Methods Between January 2011 and September 2018, 67 female BCLM patients who underwent partial hepatectomy were selected for analysis in the present study. Prognostic factors after hepatectomy were determined. Univariate and multivariate analyses were performed to identify predictors of overall survival (OS) and intrahepatic recurrence-free survival (IHRFS). Results The 1-, 3-and 5-year OS of patients treated with surgery was 93.5%, 73.7% and 32.2%, respectively, with a median survival time of 57.59 months. The Pringle manoeuvre [hazard radio (HR) = 0.117, 95% CI0.015-0.942, p = 0.044] and an increased interval between breast surgery and BCLM diagnosis (HR0.178, 95% CI 0.037-0.869, p = 0.033) independently predicted improved overall survival for BCLM patients. The 1-, 2-and 3-year IHRFS of patients who underwent surgery was 62.8, 32.6% and 10.9%, respectively, with a median intrahepatic recurrence-free survival time of 13.47 months. Moderately differentiated tumours (HR 0.259, 95% CI 0.078-0.857, p = 0.027) and the development of liver metastasis more than 2 years after breast surgery (HR 0.270, 95% CI 0.108-0.675, p = 0.005) might be predictors of increased IHRFS. Conclusions An interval of more than 2 years between breast cancer surgery and liver metastasis seems to be an indication of liver surgery in BCLM patients. The Pringle manoeuvre and moderately differentiated tumours are potential predictors associated with OS and IHRFS, respectively, as benefits from liver resection. Studies with increased sample sizes are warranted to validate our results.