Defect-induced discrete breather in dissipative optical lattices with weak nonlinearity.

It is widely believed that the discrete breather (DB) can only be created when the nonlinearity is strong in nonlinear systems. However, we here establish that this belief is incorrect. In this work, we systemically investigate the generation of DBs induced by coupling of the defects and nonlinearity for Bose-Einstein condensates in dissipative optical lattices. The results show that, only in a clean lattice is strong nonlinearity a necessary condition for generating of DB; whereas, if the lattice has a defect, the DBs can also be discovered even in weak nonlinearity, and its generation turns out to be controllable. In addition, we further reveal a critical interval of the defect in weak nonlinearity, within which DBs can be found, while outside DBs do not exist. Furthermore, we also explore the impact of multiple defects on the generation of DBs, and analyze the underlying physical mechanisms of these interesting phenomena. The results not only have the potential to be used for more precise engineering in the DB experiments, but also suggest that the DB may be ubiquitous since the defects and dissipation are unavoidable in real physics.

Value of magnetic resonance imaging radiomics features in predicting histologic grade of invasive ductal carcinoma of the breast.

BACKGROUND: Breast cancer has the second highest mortality rate of all cancers and occurs mainly in women. OBJECTIVE: To investigate the relationship between magnetic resonance imaging (MRI) radiomics features and histological grade of invasive ductal carcinoma (IDC) of the breast and to evaluate its diagnostic efficacy. METHODS: The two conventional MRI quantitative indicators, i.e. the apparent diffusion coefficient (ADC) and the initial enhancement rate, were collected from 112 patients with breast cancer. The breast cancer lesions were manually segmented in dynamic contrast-enhanced MRI (DCE-MRI) and ADC images, the differences in radiomics features between Grades I, II and III IDCs were compared and the diagnostic efficacy was evaluated. RESULTS: The ADC values (0.77 ± 0.22 vs 0.91 ± 0.22 vs 0.92 ± 0.20, F= 4.204, p< 0.01), as well as the B_sum_variance (188.51 ± 67.803 vs 265.37 ± 77.86 vs 263.74 ± 82.58, F= 6.040, p< 0.01), L_energy (0.03 ± 0.02 vs 0.13 ± 0.11 vs 0.12 ± 0.14, F= 7.118, p< 0.01) and L_sum_average (0.78 ± 0.32 vs 16.34 ± 4.23 vs 015.45 ± 3.74, F= 21.860, p< 0.001) values of patients with Grade III IDC were significantly lower than those of patients with Grades I and II IDC. The B_uniform (0.15 ± 0.12 vs 0.11 ± 0.04 vs 0.12 ± 0.03, F= 3.797, p< 0.01) and L_SRE (0.85 ± 0.07 vs 0.78 ± 0.03 vs 0.79 ± 0.32, F= 3.024, p< 0.01) values of patients with Grade III IDC were significantly higher than those of patients with Grades I and II IDC. All differences were statistically significant (p< 0.05). The ADC radiomics signature model had a higher area-under-the-curve value in identifying different grades of IDC than the ADC value model and the DCE radiomics signature model (0.869 vs 0.711 vs 0.682). The accuracy (0.812 vs 0.647 vs 0.710), specificity (0.731 vs 0.435 vs 0.342), positive predictive value (0.815 vs 0.663 vs 0.669) and negative predictive value (0.753 vs 0.570 vs 0.718) of the ADC radiomics signature model were all significantly better than the ADC value model and the DCE radiomics signature model. CONCLUSION: ADC values and breast MRI radiomics signatures are significant in identifying the histological grades of IDC, with the ADC radiomics signatures having greater value.

Analysis of characteristics of intracranial cavernous angioma and bleeding factors in middle-aged and elderly patients.

Objective: Intracranial cavernous angioma (ICA) is a cerebrovascular malformation. It causes local neurological dysfunction, epilepsy, intracranial hemorrhage (ICH) and other symptoms, seriously affecting the safety of patients. This study analyzed middle-aged and elderly patients with ICA in our hospital, summarized the characteristics of the disease and investigated the related factors of ICH. Methods: We conducted a retrospective analysis of 120 middle-aged and elderly patients who were diagnosed with ICA by magnetic resonance imaging in our hospital from March 2018 to September 2021. The cases were assigned to either a bleeding group (i.e., the experimental group) or a non-bleeding group (i.e., the control group). The characteristics of the disease, including gender, age, number of lesions, form and symptoms of onset, distribution of lesions, blood supply vessels in the lesion area, size of the lesion and presence of bleeding, were summarized and analyzed. The relationship between these factors and ICH was investigated, and the data were analyzed using SPSS 25.0 software. Results: There were 56 cases in the experimental group and 64 cases in the control group. A univariate analysis showed that gender, age, body mass index, blood lipids, number of lesions, course of the disease, onset of symptoms and disease characteristics were not associated with ICH in the middle-aged and elderly patients with ICA (P > 0.05). The maximum diameter, volume, location and blood supply area of the lesions were related to ICA complicated with ICH (P < 0.05). A multivariate unconditional logistic regression analysis revealed that the maximum diameter, volume, location and blood supply area of the lesions were independent risk factors for ICH in the middle-aged and elderly patients with ICA. The odds ratio (OR) of the maximum diameter of the lesion was 4.410, the OR of the lesion volume was 7.316, the OR of the lesion site was 7.470, and the OR of the blood supply area was 1.6588. Conclusion: Intracranial cavernous angioma lesions in middle-aged and elderly patients occur mainly in the supratentorial area, with a small part located in the infratentorial area. The main form of the disease is chronic recurrence. The occurrence of bleeding is related to the size, location and blood supply of the lesion.

Evolution Characteristics of Electromagnetic Power Radiated in Lightning Discharge Processes.

Combining the spectra of could-to-ground lightning discharge processes obtained by a slit-less spectrograph with synchronous electric field information, the temperature, the conductivity, the current peak, electromagnetic power peak and the luminance of the discharge channel are calculated. The values are in a normal range reported by references. The correlation among cut-off time before a subsequent return stroke, the luminance and electromagnetic power peak of the channel is discussed. The change trends of the conductivity, the current peak and electromagnetic power peak are also investigated. The results show when cut-off time is long, neutralized charges will grow, the current will rise and electromagnetic power radiated from the channel will increase. When the conductivity and the peak of the electric field change increase simultaneously, the current in the channel will rise and electromagnetic power radiated from the channel will be greater. This work will provide some references for calculating optical and electromagnetic energy radiated by lightning discharge processes.