Full ab initio band structure analysis of interband and intraband contributions for third harmonic generation coefficient of bulk silicon: implementation and application of the sum-over-states

We fully implement the Aversa and Sipe sum-over-states formulism and make a full ab initio band structure analysis of interband and intraband contributions for the third-order nonlinear optical susceptibilities of bulk silicon. The band structure and momentum matrix elements were calculated by using the highly accurate all-electron full potential linearized augmented plane wave method within the local density approximation. The convergence tests including the scissor correction with different k-points meshes and empty states were performed. Both real and imaginary parts of susceptibility were directly calculated and checked by the Kramers-Kronig relation. The converged results are compared with other theoretical and experimental ones and in agreement with the recent ab initio real-time-based calculation. The nonlinear optical coefficient comes from three parts: the pure interband contribution (Pinter), the modulation of interband terms by intraband terms (Pmod), and the intraband contribution (Jintra). For each part, the origin of enhanced peaks is explored by tracing the sum-over-states process. The interband contribution is found to be dramatically modulated by the intraband contribution.Comment: 11 pages, 7 figures, 2 table

Causal Discovery in Radiographic Markers of Knee Osteoarthritis and Prediction for Knee Osteoarthritis Severity With Attention-Long Short-Term Memory.

The goal of this study is to build a prognostic model to predict the severity of radiographic knee osteoarthritis (KOA) and to identify long-term disease progression risk factors for early intervention and treatment. We designed a long short-term memory (LSTM) model with an attention mechanism to predict Kellgren/Lawrence (KL) grade for knee osteoarthritis patients. The attention scores reveal a time-associated impact of different variables on KL grades. We also employed a fast causal inference (FCI) algorithm to estimate the causal relation of key variables, which will aid in clinical interpretability. Based on the clinical information of current visits, we accurately predicted the KL grade of the patient\u27s next visits with 90% accuracy. We found that joint space narrowing was a major contributor to KOA progression. Furthermore, our causal structure model indicated that knee alignments may lead to joint space narrowing, while symptoms (swelling, grinding, catching, and limited mobility) have little impact on KOA progression. This study evaluated a broad spectrum of potential risk factors from clinical data, questionnaires, and radiographic markers that are rarely considered in previous studies. Using our statistical model, providers are able to predict the risk of the future progression of KOA, which will provide a basis for selecting proper interventions, such as proceeding to joint arthroplasty for patients. Our causal model suggests that knee alignment should be considered in the primary treatment and KOA progression was independent of clinical symptoms

Magnetic resonance imaging and mammographic appearance of dermatofibrosarcoma protuberans in a male breast: a case report and literature review

<p>Abstract</p> <p>Introduction</p> <p>Dermatofibrosarcoma protuberans is a rare low-grade soft tissue neoplasm with trunk and extremities being the most common sites of involvement. We report a rare case of male breast with dermatofibrosarcoma protuberans and its imaging features. To our knowledge the imaging appearance of dermatofibrosarcoma protuberans of the breast has never been reported in the literature.</p> <p>Case presentation</p> <p>We report the imaging appearance of dermatofibrosarcoma protuberans on the breast of a 41-year-old Chinese man who initially presented with a palpable lump. A mammogram showed two lesions, one with well circumscribed and the other with an ill defined border, in his right breast. Conventional magnetic resonance imaging was performed and showed the well defined larger lesion with mild central hypointensity while the smaller lesion had an irregular border. Both lesions were well characterized on the fat-suppressed sequences.</p> <p>Conclusions</p> <p>Dermatofibrosarcoma protuberans is a rare soft tissue sarcoma and its occurrence on the breast is even rarer. Mammography and magnetic resonance imaging can help in characterizing the lesion and localizing the lesion for further diagnostic evaluation and surgical planning.</p

Expression of EPO and related factors in the liver and kidney of plain and Tibetan sheep

Erythropoietin (EPO), hypoxia-inducible factor-1α (HIF-1α), hypoxia-inducible factor-2α (HIF2α), and vascular endothelial growth factor (VEGF) are key factors in the regulation of hypoxia, and can transcriptionally activate multiple genes under hypoxic conditions, thereby initiating large hypoxic stress in the network. The liver and kidneys are important metabolic organs of the body. We assessed the expression of EPO, HIF-1α, HIF-2α, and VEGF in liver and kidney tissues of plain and Tibetan sheep using hematoxylin and eosin staining, immunohistochemistry, and RT-qPCR. The results showed that EPO, HIF-1α, HIF-2α, and VEGF were expressed in tubular epithelial cells, collecting duct epithelial cells, mural epithelial cells, and the glomerular cytoplasm of Tibetan sheep, and their expression was significantly higher in Tibetan sheep than in plain sheep (P<0.05). EPO, HIF-1α, HIF-2α, and VEGF are expressed in hepatocytes, interlobular venous endothelial cells, and interlobular bile duct epithelial cells. In plain sheep, positive signals for EPO, HIF-1α, HIF-2α, and VEGF were localized mainly in interlobular venous endothelial cells, whereas VEGF and HIF-2α were negatively expressed in interlobular bile duct epithelial cells and positively expressed in EPO and HIF-1α. The differences in EPO, HIF-1α, and HIF-2α in Tibetan sheep were significantly higher than those in plain sheep (P<0.001). In the liver and kidney tissues of Tibetan sheep, EPO was associated with HIF-1α, HIF-2α, and VEGF (P<0.05). RT-qPCR results showed that EPO was not expressed, and HIF-1α, HIF-2α, and VEGF were expressed (P<0.05). The results showed that the expression of EPO, HIF-1α, HIF-2α, and VEGF in the kidney and liver of Tibetan sheep was higher than that in of plain sheep. Therefore, EPO, HIF-1α, HIF-2α, and VEGF may be involved in the adaptive response of plateau animals, which provides theoretical clarity to further explore the adaptive mechanism of plateau hypoxia in Tibetan sheep