Damage characteristics of weak rocks with different dip angles during creep.

To investigate the influence of the weak layer dip angle on the creep rupture of the composite rock mass, this paper conducts a graded loading creep experiment on the composite rock mass with different dip angles using the acoustic emission method to examine the fracture evolution process. With increasing load grade, the cumulative total ring count of the rock mass shows a "U"-shaped trend, and the acoustic emission spatial positioning results show that acoustic emission events in the rock mass fracture process are primarily concentrated in the vicinity of the weak layer, while events in other areas are few and dispersed. For rock masses with weak layer dip angles of 0° and 15°, cracks occur in both soft and hard rocks, where shear cracks are dominant in soft rocks, tensile cracks are dominant in hard rocks, and finally, the rock mass mainly exhibits tensile splitting failure. For rock masses with weak layer dip angles of 30° and 45°, most of the cracks exist in the interior of the soft rock, which is dominated by shear cracks. With increasing graded loads, the shear cracks continue to develop along the direction of the weak layer, the upper rock mass keeps slipping and dislocating, and the final failure mode is mainly shear-slip failure. The damage evolution varies with the inclination angle of the weak layer, which can be divided into three stages: initial damage accumulation, damage acceleration, and damage destruction. This demonstrates the ability to predict, prevent, and control the occurrence of creep disasters in rock masses with weak layers.

The Effect of Combination Use of Hemodialysis and Hemoperfusion on Microinflammation in Elderly Patients with Maintenance Hemodialysis.

BACKGROUND: Patients with maintenance hemodialysis (MHD) generally have a microinflammatory state. The aim of this study was to investigate the effects of hemodialysis (HD) combined with hemoperfusion (HP) on microinflammatory state in elderly patients with MHD. METHODS: One hundred and fifty elderly patients with MHD were randomly divided into the control group and the observation group. The control group received simple HD treatment, and the observation group received combined HD + HP treatment on the basis of the control group. After 6 months of continuous treatment, the patients were evaluated to compare the quality of life, inflammation, adverse reactions, and nutritional indicators in the 2 groups before and after treatment. RESULTS: There was no significant difference in the quality of life between the 2 groups before treatment. After treatment, the scores of psychological aspects, physiological aspects, social aspects, environmental aspects, and independent ability in the observation group were higher than those in the control group, with statistical significance (p < 0.05). There was no statistical significance in the level of inflammation between 2 groups before treatment. After treatment, the levels of hs-CRP, Hcy, IL-6, and TNF-α in the observation group were significantly lower than those in the control group, with statistical significance (p < 0.05). The incidence of dry mouth, skin reaction, neuritis, and subcutaneous tissue fibrosis in the observation group was lower than that in the control group, with statistical significance (p < 0.05). There was no statistical significance in nutritional level indexes between 2 groups before treatment (p1 > 0.05). After treatment, the levels of hemoglobin, total protein, albumin, and transferrin in the observation group were significantly higher than those in the control group, with statistical significance (p < 0.05). CONCLUSION: The clinical effect of HD combined with HP in elderly MHD patients is significant, which can effectively reduce the incidence of adverse reactions and inflammation in the patients and improve the quality of life and nutritional indicators of the patients.

Initiation and Suppression of Crack Propagation during Magnesium Alloy Rolling.

The conventional rolling of magnesium alloy with a single pass and large reduction will cause severe edge cracking. The sheet without cracks can be achieved by limited width rolling. The microstructure evolution of the sheet with cracks after conventional rolling and the sheet without cracks after limited width rolling is explored, and an effective mechanism for solving edge cracks is proposed. Conventional rolling can fully develop twin evolution due to high deformation, and three stages of twinning evolution can be observed and the secondary twins easily become the nucleation points of micro cracks, resulting in a large number of cracks propagating along the twin lamellae. Cracks terminate at dislocation accumulation because the accumulation of a large number of dislocations can hinder propagation. Dislocation shearing of twins to eliminate the high localization caused by twins and induce the tensile twins to weaken the basal surface texture provides an effective plastic deformation mechanism of crack inhibition, which is useful for expanding the engineering application of magnesium alloy rolled sheets.

Antianginal efficacy of ranolazine when added to treatment with amlodipine: the ERICA (Efficacy of Ranolazine in Chronic Angina) trial.

OBJECTIVES: The purpose of this study was to determine if ranolazine improves angina in stable coronary patients with persisting symptoms despite maximum recommended dose of amlodipine. BACKGROUND: Ranolazine is a unique antianginal agent that has been effective in stable angina, but it has not been studied in the setting of maximum recommended doses of conventional antianginal agents. METHODS: Stable patients with coronary disease and > or =3 anginal attacks per week despite maximum recommended dosage of amlodipine (10 mg/day) were randomized to 1,000 mg ranolazine or placebo twice a day for 6 weeks. Primary end point was the frequency of angina episodes per week during the double-blind treatment phase. Efficacy was also assessed by nitroglycerin consumption per week and the Seattle Angina Questionnaire (SAQ). Adjustment for multiple testing of secondary end points used a hierarchic closed testing procedure. Efficacy was assessed in subgroups based on baseline angina frequency, concomitant long-acting nitrate use, gender, and age. Safety was assessed by adverse events and electrocardiogram evaluations. RESULTS: A total of 565 patients were randomized: 281 patients to ranolazine and 284 patients to placebo. Baseline characteristics were similar between treatment groups. At baseline, angina frequency averaged 5.63 +/- 0.18 episodes/week, and nitroglycerin consumption averaged 4.72 +/- 0.21 tablets/week. Compared with placebo, ranolazine significantly reduced frequency of angina episodes (2.88 +/- 0.19 on ranolazine vs. 3.31 +/- 0.22 on placebo; p = 0.028) and nitroglycerin consumption (2.03 +/- 0.20 on ranolazine vs. 2.68 +/- 0.22; p = 0.014), with treatment effect that appeared consistent across subgroups. The median angina weekly episode rate at baseline was 4.5 per week. Subgroup analysis showed statistically significant reductions of angina frequency, nitroglycerin use, and SAQ angina frequency for patients with a baseline frequency >4.5 per week but only of angina frequency for those with baseline frequency < or =4.5 per week. Patients with more frequent angina appeared to have a more pronounced treatment effect. No hemodynamic changes were observed. Ranolazine was well tolerated. CONCLUSIONS: Ranolazine significantly reduced frequency of angina and nitroglycerin consumption compared with placebo and was well tolerated. (The ERICA [Efficacy of Ranolazine In Chronic Angina] Trial; http://clinicaltrials.gov; NCT00091429).

Trial to evaluate the management of paroxysmal supraventricular tachycardia during an electrophysiology study with tecadenoson.

BACKGROUND: Tecadenoson is a potent selective A1-adenosine receptor agonist with a dose-dependent negative dromotropic effect on the AV node. Tecadenoson terminates induced paroxysmal supraventricular tachycardia (PSVT) without the clinically significant side effects caused by stimulation of other adenosine receptors. This trial was designed to determine a safe and effective tecadenoson bolus for termination of electrophysiologically induced PSVT. METHODS AND RESULTS: Patients with a history of symptomatic PSVT and inducible PSVT at the time of a clinically indicated electrophysiology study were randomized into a multicenter, double-blind, placebo-controlled trial. Five 2-dose tecadenoson bolus regimens were evaluated versus placebo (75/150, 150/300, 300/600, 450/900, 900 microg/900 microg). The second bolus was administered only if PSVT persisted for 1 minute after the first bolus. Each tecadenoson regimen resulted in a significant therapeutic conversion rate compared with placebo (range, 50.0% to 90.3%, analysis of all patients dosed; n=181; P<0.0005). Conversion by the first bolus was dose related (range: placebo, 3.3% to 86.7% for 900 microg/900 microg). Time to conversion was dose dependent, with a median time of <1 minute for the 3 highest dose regimens. Postconversion arrhythmias were transient, requiring no additional treatment in 4 regimens (including placebo). Transient second- and third-degree heart block occurred at higher doses (300/600, 450/900, 900 microg/900 microg) and was supported with backup pacing when needed. No effect on blood pressure was observed. Ten patients with a history of asthma or chronic obstructive pulmonary disease tolerated tecadenoson without bronchospasm. CONCLUSIONS: We identified an optimal tecadenoson regimen (300 microg/600 microg) that effectively and rapidly converted 90% (28 of 31) of PSVT patients to normal sinus rhythm with no significant adverse effects.