New approaches to inventory control: algorithms, asymptotics and robustness

The fundamental problem of managing an inventory over time in the presence of stochastic demand is one of the core problems of operations research. This thesis is motivated by the need (in both government and industry) to understand such complex inventory systems used to model many of society's most important problems. In particular, we investigate simple, efficient and robust inventory policies for several fundamental models commonly used in the study of stochastic inventory systems. Some of these policies have been already implemented in practice and we provide strong theoretic support for their practical utilization in industry. Furthermore, the results on the performance of these policies often yield a rule-of-thumb that is applicable in a variety of settings.Ph.D

Poly[[bis­(μ2-6-methyl­pyrazin-2-carboxyl­ato-κ3 N 1,O:N 4)copper(II)] dihydrate]

In the title compound, {[Cu(C6H5N2O2)2]·2H2O}n, the CuII ion (site symmetry ) is coordinated by two N,O-bidentate ligands and two N-monodentate ligands in a distorted CuO2N4 octa­hedral geometry. Each anion acts as a bridge between two cations, thus forming a two-dimensional polymeric network parallel to the ab plane. The packing is consolidated by O—H⋯O hydrogen bonds. One of the O atoms of the ligand and both water mol­ecules are disordered

Characterization of immune microenvironment identifies prognostic and immunotherapy benefit for trastuzumab-based therapy

Background and Purpose: The tumor immune microenvironment (TIME) of breast cancer with positive human epidermal growth factor receptor 2 (HER2) is significantly related to the efficacy of trastuzumab, indicating the clinical potential of immunocheckpoint therapy combined with trastuzumab. This study aimed to explore the predictors of HER2-positive breast cancer combination therapy and screen the potential beneficiaries of combination therapy. Methods: Transcriptome and genome data of 509 HER2-positive breast cancer samples of patients receiving trastuzumab treatment from Gene Expression Omnibus (GEO) database and 67 HER2-positive breast cancer samples from The Cancer Genome Atlas (TCGA) databases were collected. Trastuzumab-resistant group’s differentially expressed genes were identified and analyzed for functional enrichment and protein-protein interaction. The log-rank test and multivariate COX proportional hazards regression were used with clinical data to create the prediction model. The TIME landscape was characterized using the CIBERSORT. The immunotherapy benefit was valued by the tumor immune dysfunction and exclusion (TIDE) score. Results: The trastuzumab related genetic prognostic index (TRGPI) consisting of four hub genes (GATA6, TRPV6, AMACR, ZHX2) was constructed by analyzing the immune microenvironment and gene expression characteristics between trastuzumab-remission group and trastuzumab-resistance group. Importantly, the results revealed that patients with lower TRPGI were trastuzumab-sensitive and more likely to benefit from immunotherapy because of the increased percentages of CD8+ T cells, active natural killer cells and programmed death-1 (PD-1) expression. Conclusion: This study redefined the benefit population through TIME and provided a selectable strategy of trastuzumab plus immunotherapy for HER2-positive breast cancer

Neuropathologic damage induced by radiofrequency ablation at different temperatures

Objective: To explore the molecular mechanism of neuropathologic damage induced by radiofrequency ablation at different temperatures. Methods: This is basic research, and 36 SD rats were used to construct the neuropathological injury model. The rats were subjected to radiofrequency stimulation at different temperatures and were divided into 6 groups according to the temperature injury: 42°, 47°, 52°, 57°, 62°, and 67°C groups. Conduction time, conduction distance, and nerve conduction velocity were recorded after temperature injury. HE-staining was used to observe the histopathological morphology of the sciatic nerve. The expression of SCN9A, SCN3B, and NFASC protein in sciatic nerve tissue were detected by western blot. Results: With the increase in temperature, nerve conduction velocity gradually decreased, and neurons were damaged when the temperature was 67°C. HE-staining showed that the degrees of degeneration of neurons in rats at 47°, 52°, 57°, 62°, and 67°C were gradually increased. The expression of SCN9A, SCN3B protein in 57°, 62°, 67°C groups were much higher than that of NC, 42°, 47°, 52°C groups. However, the expression of NFASC protein in 57°, 62°, 67°C groups was much lower than that of the NC, 42°, 47°, 52°C groups. Conclusion: There was a positive correlation between temperature caused by the radiofrequency stimulation to neuropathological damage. The mechanism is closely related to the expression of SCN9A, SCN3B, and NFASC protein in nerve tissue caused by heat transfer injury