Mechanical Properties of Aeolian Sand Concrete Made from Alkali-Treated Aeolian Sand and Zeolite Powder

The aim of this study is to promote the application of the excited zeolite powder (ZP)with aeolian sand powder (ASP) in the field of aeolian-sand concrete (ASC) production. This study utilises NaOH to treat composite cementitious materials containing aeolian sand and zeolite powders, which were used to replace 50% of the cement in aeolian-sand concrete (ASC). Production of alkali-inspired cement-based windswept concrete(AAZC).The mechanical properties of treated ASC considerably improved, especially when the NaOH dosage was 4% by mass. After curing this sample (denoted as AAZC-4) for 28 d, its compressive strength improved by 17.2%, and its split tensile increased by 16.3%. Potassium feldspar and montmorillonite in zeolite powder and SiO2 in the sand were decomposed by OH− and combined with other elements to generate various silicate gels and A-type potassium zeolite crystals inside the concrete. Microscopic examination showed that the gels and crystals intertwined to fill the pores, decreasing (increasing) the percentage of large (small) pores, thus optimising the pore structure. This substantially improved the mechanical properties of ASC. Freeze–thaw salt-intrusion tests showed that the extent of mass loss, degree of damage and loss of compressive strength of AAZC-4 were similar to those of ordinary concrete but were reduced by 36.8%, 19% and 52.1%, respectively, compared with those of ASC. Therefore, AAZC-4 has a sustainable working performance in chloride-ion permeable environments in cold and arid areas

Agronomic evaluation of nutrient management for potato in Northwest China

In northwest China the lack of knowledge on soil nutrient fertility and of appropriate nutrient management practices has restricted potato production. Field trials were conducted from 2002 to 2007 to determine the main limiting nutrients for potato (Solanum tuberosum L), and to evaluate the nutrient management practice (NMP) based on an Agro Services International (ASI) systematic approach. Results indicated that average potato yields in nutrient omission plots were in the order 0-N (22.2 t ha-1) ≈ 0-P (22.4 t ha-1) < 0-K (31.5 t ha-1). N deficiency is a general feature of irrigated potato in northwest region, but P and K supply are frequently additional limiting factors. The mean agronomic efficiencies (AE) of N, P and K were 34.4 kg tuber kg-1 N, 32.4 kg tuber kg-1 P2O5 and 41.3 kg tuber kg-1 K2O, respectively, and the mean partial factor productivities (PFP) of N, P and K were 220 kg tuber kg-1 N, 291 kg tuber kg-1 P2O5 and 306 kg tuber kg-1 K2O, respectively. There was a significant negative relationship between AE or PFP of N, P or K and the respective nutrient rate. The positive relationship between yield of nutrient omission plots and PFP and AE suggests nutrient use efficiency is affected by soil indigenous productivity. NMP based on an ASI systematic approach produced significant higher yields, nutrient use efficiencies and economic returns than farmer’s practice

Rationale, design, and baseline characteristics in Evaluation of LIXisenatide in Acute Coronary Syndrome, a long-term cardiovascular end point trial of lixisenatide versus placebo

BACKGROUND: Cardiovascular (CV) disease is the leading cause of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM). Furthermore, patients with T2DM and acute coronary syndrome (ACS) have a particularly high risk of CV events. The glucagon-like peptide 1 receptor agonist, lixisenatide, improves glycemia, but its effects on CV events have not been thoroughly evaluated. METHODS: ELIXA (www.clinicaltrials.gov no. NCT01147250) is a randomized, double-blind, placebo-controlled, parallel-group, multicenter study of lixisenatide in patients with T2DM and a recent ACS event. The primary aim is to evaluate the effects of lixisenatide on CV morbidity and mortality in a population at high CV risk. The primary efficacy end point is a composite of time to CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. Data are systematically collected for safety outcomes, including hypoglycemia, pancreatitis, and malignancy. RESULTS: Enrollment began in July 2010 and ended in August 2013; 6,068 patients from 49 countries were randomized. Of these, 69% are men and 75% are white; at baseline, the mean ± SD age was 60.3 ± 9.7 years, body mass index was 30.2 ± 5.7 kg/m(2), and duration of T2DM was 9.3 ± 8.2 years. The qualifying ACS was a myocardial infarction in 83% and unstable angina in 17%. The study will continue until the positive adjudication of the protocol-specified number of primary CV events. CONCLUSION: ELIXA will be the first trial to report the safety and efficacy of a glucagon-like peptide 1 receptor agonist in people with T2DM and high CV event risk