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Hemoproteins have recently emerged as attractive biocatalysts for catalyzing carbene-mediated cyclopropanation, a synthetically valuable reaction not found in nature. In this study, we present a hemoglobin-catalyzed strategy for the highly stereoselective synthesis of nitrile-substituted cyclopropanes. This method offers efficiency and environmental friendliness by utilizing an asymmetric olefin cyclopropanation reaction catalyzed by wild-type Vitreoscilla hemoglobin in the presence of in situ generated diazoacetonitrile. A diverse range of nitrile-substituted cyclopropanes could be synthesized in water with exceptional stereoselectivity, achieving up to 99.9% de and ee and high turnover numbers of up to 3232. By employing this sustainable approach, not only can various chiral nitrile-substituted cyclopropanes be efficiently obtained, but also the practical application of hemoglobin in organic synthesis can be expanded. [ABSTRACT FROM AUTHOR]

In this paper, we design a new branch-and-bound algorithm to solve a variant of graph partition problem called two-level graph partition problem, which is arisen in mobile wireless communications. We first exploit the two-level structure of the problem, and propose a new semidefinite relaxation for the problem. Some valid constraints are derived to enhance the tightness of the semidefinite relaxation. Furthermore, we analyze the symmetric structure of the two-level graph partition problem, and propose an effective branch pruning rule to handle the symmetry. Based on the proposed semidefinite relaxation and the symmetry handing technique, a branch-and-bound algorithm is proposed. Our numerical results show that the proposed algorithm outperforms the existing linear integer programming based algorithm on two-level graph partition problems with high density. [ABSTRACT FROM AUTHOR]

Purpose: Multiple myeloma (MM), the second most hematological malignancy, have been studied extensively in the prognosis of the clinical parameters, however there are only a few studies have discussed the role of dual modalities and multiple algorithms of 18F-FDG (18F-fluorodeoxyglucose) PET/CT based radiomics signatures for prognosis in MM patients. We hope to deeply mine the utility of raiomics data in the prognosis of MM. Methods: We extensively explored the predictive ability and clinical decision-making ability of different combination image data of PET, CT, clinical parameters and six machine learning algorithms, Cox proportional hazards model (Cox), linear gradient boosting models based on Cox's partial likelihood (GB-Cox), Cox model by likelihood based boosting (CoxBoost), generalized boosted regression modelling (GBM), random forests for survival model (RFS) and support vector regression for censored data model (SVCR). And the model evaluation methods include Harrell concordance index, time dependent receiver operating characteristic (ROC) curve, and decision curve analysis (DCA). Results: We finally confirmed 5 PET based features, and 4 CT based features, as well as 6 clinical derived features significantly related to progression free survival (PFS) and we included them in the model construction. In various modalities combinations, RSF and GBM algorithms significantly improved the accuracy and clinical net benefit of predicting prognosis compared with other algorithms. For all combinations of various modalities based models, single-modality PET based prognostic models' performance was outperformed baseline clinical parameters based models, while the performance of models of PET and CT combined with clinical parameters was significantly improved in various algorithms. Conclusion: 18F‑FDG PET/CT based radiomics models implemented with machine learning algorithms can significantly improve the clinical prediction of progress and increased clinical benefits providing prospects for clinical prognostic stratification for precision treatment as well as new research areas. [ABSTRACT FROM AUTHOR]

Purpose: Digestive system tumors are a group of tumors with high incidence in the world nowadays. The assessment of digestive system tumor metastasis by conventional imaging seems to be unsatisfactory. [68Ga]Ga-FAPI, which has emerged in recent years, seems to be able to evaluate digestive system tumor metastasis. We aimed to summarize the current evidence of [68Ga]Ga-FAPI PET/CT or PET/MR for the assessment of primary tumors, lymph node metastases, and distant metastases in digestive system tumors. Besides, we also aimed to perform a meta-analysis of the sensitivity of [68Ga]Ga-FAPI PET diagnosis to discriminate between digestive system tumors, primary lesions, and non-primary lesions (lymph node metastases and distant metastases). Materials and methods: PubMed, MEDLINE and Cochrane Library databases were searched from the beginning of the database build to August 12, 2022. All studies undergoing [68Ga]Ga-FAPI PET for the evaluation of digestive tumors were included in the screening and review. Screening and full text review was performed by 3 investigators and data extraction was performed by 2 investigators. Risk of bias was examined with the QUADAS-2 criteria. Diagnostic test meta-analysis was performed with a random-effects model. Results: A total of 541 studies were retrieved. Finally, 22 studies were selected for the systematic review and 18 studies were included in the meta-analysis. In the 18 publications, a total of 524 patients with digestive system tumors, 459 primary tumor lesions of digestive system tumors, and 1921 metastatic lesions of digestive system tumors were included in the meta-analysis. Based on patients, the sensitivity of [68Ga]Ga-FAPI PET for the diagnosis of digestive system tumors was 0.98 (95% CI: 0.94–0.99). Based on lesions, the sensitivity of [68Ga]Ga-FAPI PET for the diagnostic evaluation of primary tumor lesions of the digestive system was 0.97 (95% CI: 0.93–0.99); the sensitivity of [68Ga]Ga-FAPI PET for the diagnostic evaluation of non-primary lesions (lymph node metastases and distant metastases) of the digestive system tumors was 0.94 (95% CI: 0.79–0.99). Conclusion: [68Ga]Ga-FAPI PET has high accuracy and its sensitivity is at a high level for the diagnostic evaluation of digestive system tumors. Clinicians, nuclear medicine physicians, and radiologists may consider using [68Ga]Ga-FAPI PET/CT or PET/MR in the evaluation of primary tumors, lymph node metastases, and distant metastases in digestive system tumors. [ABSTRACT FROM AUTHOR]