Direct phasing algorithm for protein crystals with high solvent content using low-resolution diffraction data.

Over the past decade, iterative projection algorithms, an effective approach to recovering phases from a single intensity measurement, have found application in protein crystallography to directly surmount the `phase problem'. However, previous studies have always assumed that some prior knowledge constraints (i.e. a low-resolution envelope about the protein structure in the crystal cell or histogram matching requiring a similar density distribution to the target crystal) must be known for successful phase retrieval, thus hindering its widespread application. In this study, a novel phase-retrieval workflow is proposed that eliminates the need for a reference density distribution by utilizing low-resolution diffraction data in phasing algorithms. The approach involves randomly assigning one out of 12 possible phases at 30° intervals (or two for centric reflections) to produce an initial envelope, which is then refined through density modification after each run of phase retrieval. To evaluate the success of the phase-retrieval procedure, information entropy is introduced as a new metric. This approach was validated using ten protein structures with high solvent content, demonstrating its effectiveness and robustness.

Characteristics of fibrotic-foci-like lung adenocarcinoma on 18 F-FDG PET/computed tomography and HRCT.

PURPOSE: To assess the characteristics of fibrotic-foci-like lung adenocarcinoma on 18 F-fluorodeoxyglucose PET/computed tomography ( 18 F-FDG PET/CT) and high-resolution computed tomography (HRCT). MATERIAL AND METHODS: This was a retrospective study with 20 cases in the fibrotic-foci-like lung adenocarcinoma group; the control group was old fibrotic-foci of the lung with 20 cases. The following 18 F-FDG PET/CT and HRCT features were evaluated: the maximum standardized uptake value (SUVmax); the tumor-to-background ratios of SUVmax (TBRmax); the long-to-short diameter ratio (L/S); anatomic location; location type; internal characteristics; marginal characteristics and surrounding structures. In the fibrotic-foci-like lung adenocarcinoma group, a comparison of 18 F-FDG uptake between the metastatic group ( n  = 10) and the non-metastatic group ( n  = 10) was performed. Finally, the comparison of diagnostic accuracy for fibrotic-foci-like lung adenocarcinoma between 18 F-FDG PET/CT and HRCT was performed. RESULTS: The SUVmax [2.6 (1.7-7.9) vs. 1.0 (0.7-1.4)], TBRmax [2.9 (2.1-9.9) vs. 1.3 (1.2- 1.7)], L/S [2.4 (1.7-3.8) vs. 4.0 (3.2-6.3)], ground-glass opacity (GGO) [13/20 (65.0%) vs. 4/20 (20.0%)], and vessel convergence [7/20 (35.0%) vs. 1/20 (5.0%)] were found to be statistically significant differences between the fibrotic-foci-like lung adenocarcinoma group and the old fibrotic-foci group ( P  < 0.05). SUVmax [7.9 (4.7-8.8) vs. 1.7 (1.2-2.2)] and TBRmax [9.9 (6.5-11.0) vs. 2.1 (1.6-2.9)] were found to be statistically significant differences between the metastatic group and the non-metastatic group ( P  < 0.05). 18 F-FDG PET/CT showed the higher diagnostic accuracy for fibrotic-foci-like lung adenocarcinoma than HRCT [95.0% (19/20) vs. 65.0% (13/20), P  < 0.05]. CONCLUSION: The specific characteristics of fibrotic-foci-like lung adenocarcinoma on 18 F-FDG PET/CT and HRCT were high 18 F-FDG uptake, GGO, and vessel convergence, which could be distinguished from old fibrotic-foci of the lung.

A reference-based multi-lattice indexing method integrating prior information correction and iterative refinement in protein crystallography.

A new multi-lattice indexing method based on the principle of whole-pattern matching given cell dimensions and space-group symmetry is presented for macromolecular crystallography. The proposed method, termed the multi-crystal data processing suite (MCDPS), features a local correction for prior information accompanied by iterative refinement of experimental parameters, both of which are numerically and experimentally demonstrated to be critical for accurately identifying multiple crystal lattices. Further analysis of data reduction and structure determination with conventional single-crystal programs reveals that the processed multi-lattice data sets are comparable in quality to typical single-crystal ones in terms of crystallographic metrics. Importantly, it is confirmed that careful exclusion of overlapping reflections prior to scaling is necessary to guarantee an accurate data reduction result. The potential for multi-lattice indexing in solving the general macroscopic twinning problem is also explored.

Impact of timing of adjuvant chemotherapy on survival in stage III colon cancer: a population-based study.

BACKGROUND: There is no consensus regarding the optimal time to initiate adjuvant chemotherapy after surgery for stage III colon cancer, and the relevant postoperative complications that cause delays in adjuvant chemotherapy are unknown. METHODS: Eligible patients aged ≥66 years who were diagnosed with stage III colon cancer from 1992 to 2008 were identified using the linked Surveillance, Epidemiology, and End Results-Medicare database. Kaplan-Meier analysis and a Cox proportional hazards model were utilized to evaluate the impact of the timing of adjuvant chemotherapy on overall survival (OS). RESULTS: A total of 18,491 patients were included. Delayed adjuvant chemotherapy was associated with worse OS (9-12 weeks: hazard ratio [HR] = 1.222, 95% confidence interval [CI] = 1.063-1.405; 13-16 weeks: HR = 1.252, 95% CI = 1.041-1.505; ≥ 17 weeks: HR = 1.969, 95% CI = 1.663-2.331). The efficacies of adjuvant chemotherapy within 5-8 weeks and ≤4 weeks were similar (HR = 1.045, 95% CI = 0.921-1.185). Compared with the non-chemotherapy group, chemotherapy initiated at ≥21 weeks did not significantly improve OS (HR = 0.882, 95% CI = 0.763-1.018). Patients with postoperative complications, particularly cardiac arrest, ostomy infection, shock, and septicemia, had a significantly higher risk of a 4- to 11-week delay in adjuvant chemotherapy (p < 0.05). CONCLUSIONS: Adjuvant chemotherapy initiated within 8 weeks was acceptable for patients with stage III colon cancer. Delayed adjuvant chemotherapy after 8 weeks was significantly associated with worse OS. However, adjuvant chemotherapy might still be useful even with a delay of approximately 5 months. Moreover, postoperative complications were significantly associated with delayed adjuvant chemotherapy.