Learning to Cut via Hierarchical Sequence/Set Model for Efficient Mixed-Integer Programming.

Cutting planes (cuts) play an important role in solving mixed-integer linear programs (MILPs), which formulate many important real-world applications. Cut selection heavily depends on (P1) which cuts to prefer and (P2) how many cuts to select. Although modern MILP solvers tackle (P1)-(P2) by human-designed heuristics, machine learning carries the potential to learn more effective heuristics. However, many existing learning-based methods learn which cuts to prefer, neglecting the importance of learning how many cuts to select. Moreover, we observe that (P3) what order of selected cuts to prefer significantly impacts the efficiency of MILP solvers as well. To address these challenges, we propose a novel hierarchical sequence/set model (HEM) to learn cut selection policies. Specifically, HEM is a bi-level model: (1) a higher-level module that learns how many cuts to select, (2) and a lower-level module-that formulates the cut selection as a sequence/set to sequence learning problem-to learn policies selecting an ordered subset with the cardinality determined by the higher-level module. To the best of our knowledge, HEM is the first data-driven methodology that well tackles (P1)-(P3) simultaneously. Experiments demonstrate that HEM significantly improves the efficiency of solving MILPs on eleven challenging MILP benchmarks, including two Huawei's real problems.

Mg-MOF-74 Derived Defective Framework for Hydrogen Storage at Above-Ambient Temperature Assisted by Pt Catalyst.

Metal-organic frameworks (MOFs) are promising candidates for room-temperature hydrogen storage materials after modification, thanks to their ability to chemisorb hydrogen. However, the hydrogen adsorption strength of these modified MOFs remains insufficient to meet the capacity and safety requirements of hydrogen storage systems. To address this challenge, a highly defective framework material known as de-MgMOF is prepared by gently annealing Mg-MOF-74. This material retains some of the crystal properties of the original Mg-MOF-74 and exhibits exceptional hydrogen storage capacity at above-ambient temperatures. The MgO5 knots around linker vacancies in de-MgMOF can adsorb a significant amount of dissociated and nondissociated hydrogen, with adsorption enthalpies ranging from -22.7 to -43.6 kJ mol-1, indicating a strong chemisorption interaction. By leveraging a spillover catalyst of Pt, the material achieves a reversible hydrogen storage capacity of 2.55 wt.% at 160 °C and 81 bar. Additionally, this material offers rapid hydrogen uptake/release, stable cycling, and convenient storage capabilities. A comprehensive techno-economic analysis demonstrates that this material outperforms many other hydrogen storage materials at the system level for on-board applications.

Weight loss and all-cause mortality: A propensity score matching cohort study.

BACKGROUND: Weight loss was supposed to help with decreasing risk of premature mortality. However, results on this topic remain debatable and limited by study design. OBJECTIVE: The present study aimed to investigate the association between weight loss and all-cause mortality among US adults with overweight or obesity in a national cohort study by using propensity score matching (PSM) analysis. METHODS: A total of 5486 pairs of participants were matched in the National Health and Nutrition Examination Survey (NHANES, 2003-2015) after PSM. Hazard ratios (95% confidence intervals) (HRs (95% CIs)) were employed to evaluate the association between weight loss indicated by long-term weight loss (LTWL) and all-cause mortality by using Cox proportional hazards regression models. RESULTS: During a median follow-up of 6.8 years, 674 participants died from all-cause mortality. In each PSM match, compared with participants with LTWL < 5%, the HRs (95% CIs) for participants with LTWL of 5-9.9% (2877 pairs), 10-14.9% (1315 pairs), and ≥ 15% (1294 pairs) were 1.18 (0.83-1.68) (P = 0.366), 1.65 (1.17-2.34) (P = 0.005), and 1.91 (1.21-3.00) (P = 0.006), respectively. The significant increased risk of all-cause mortality for LTWL ≥ 15% remained among male, female, participants aged ≥ 65 years, without weight loss intention, with non-communicable diseases, and without exceeding estimated energy requirement. CONCLUSION: Weight loss especially for being ≥ 15% should be cautious for US adults with overweight or obesity.

Microbial Inactivation Property of Pulsed Corona Discharge Plasma and Its Effect on Chilled Pork Preservation.

Although plasma, especially atmospheric plasma generated by corona discharge, has been proven to be effective in sterilization and food preservation, its disinfection mechanism on chilled pork is poorly understood. In this research, the bactericidal and preservation effect of corona discharge plasma (CDP) was investigated. The maximum bactericidal effect was found after 20 kV 4 kHz CDP treatment, with 2.77 log (colony-forming unit [CFU]/g), 2.41 log (CFU/g), and 1.36 log (CFU/g) reduction for Pantoea agglomerans, Serratia liquefaciens, and Kurthia zopfii, respectively, after 10 min of exposure. The efficiency of microbial inactivation was attributed to the increase of ozone, hydrogen peroxide and morphological changes. It was observed that the microbial level and total volatile binding nitrogen value of CDP-treated chilled pork samples were suppressed during storage, whereas the increase of thiobarbituric acid reactive substances value and the changes of color were still worthy of attention. The aim of this study was to explore the effect of pulsed CDP on the inactivation of spoilage microorganism inoculated on the surface of fresh pork. The prospect of this technology in meat preservation industry was also investigated.

Nutritional status, lifestyle habits and cancer mortality: a population-based prospective cohort study.

PURPOSE: We aimed to investigate the relationship between overall nutritional status and cancer mortality. METHODS: A total of 12 262 US adults from six consecutive surveys of the National Health and Nutrition Examination Survey (NHANES 2003-2014) were analyzed. The overall health nutritional biomarkers index (HNBI) score, capturing characteristics of 17 biomarkers was developed to assess the overall nutritional status. The lower the HNBI score, the healthier nutritional status would be. Hazard ratio (HR) and 95% confidence intervals (95% CIs) were calculated by Cox proportional hazards regression models to evaluate the association between the HNBI score and cancer mortality. RESULTS: The lower overall HNBI score was associated with decreased risk of cancer mortality, compared with participants in the 4th quartile of overall HNBI score, the HR (95% CIs) for participants in the 1st quartiles was 0.54 (0.33-0.89) (P-trend = 0.019). Healthier lifestyle habits and not obesity interacted with HNBI score, compared with participants with higher HNBI score and smoking currently/not exercising regularly/obesity, participants with lower HNBI score and not smoking currently/exercising regularly/not obesity were associated with lower risk of cancer mortality, the HR (95% CIs) were 0.43 (0.26-0.73), 0.57 (0.33-0.97), and 0.62 (0.47-0.97), respectively. These significant associations remained among participants who were followed-up more than 2 years. CONCLUSION: Our findings suggested that healthier overall nutritional status was associated with lower risk of cancer mortality among US adults. Not smoking, exercise regularly and not obesity interacted with overall nutritional status. Adherence to better overall nutritional status, lifestyle habits and optimal weight would prevent premature death from cancer.

Trends in Nutritional Biomarkers by Demographic Characteristics Across 14 Years Among US Adults.

Background: Understanding trend in nutritional status is crucial to inform national health priorities to improve diets and reduce related diseases. The present study aimed to analyze trends in the concentrations of all measured nutritional biomarkers and their status among US adults across 14 years. Methods: Trends on the concentrations of nutritional biomarkers and nutritional status evaluated by the prevalence of deficiency, inadequacy, excess, and dyslipidemia were analyzed among US adults in 7 cross-sectional National Health and Nutrition Examination Surveys (NHANES 2003-2016) and by age, sex, race/ethnicity, and socioeconomic status. Results: A total of 38,505 participants (weighted mean age of 47.2 years, 51.4% women) were included in the present study. Across 14 years, increased trends were found in red blood cell (RBC) folate, serum vitamin B12, vitamin D and albumin, the prevalence of iodine deficiency, vitamin B6 inadequacy, and hypophosphatemia, whereas decreased trends were observed in serum vitamin E, phosphorus, total calcium, total protein, apolipoprotein B (Apo B), low-density-lipoprotein cholesterol (LDL-C), triglyceride (TG), total cholesterol (TC), blood lead, cadmium, mercury, and the prevalence of vitamin C deficiency, vitamin D inadequacy, iodine excess, and dyslipidemia with elevated LDL-C, TC, TG, and lowered HDL/LDL. Non-Hispanic blacks (NHB) and participants with low socioeconomic status were accounted for the poor nutritional status of most biomarkers compared to their comparts. Conclusion: Most nutritional biomarkers and their status were improved among US adults from 2003 to 2016, but some specific populations should be paid much attention to improve their nutritional status, especially for NHB and participants with low socioeconomic status.