27 research outputs found
The influence of the number of free surfaces on the energy distribution and attenuation law of blasting vibration signals from peripheral holes: field experiment and simulation
Tunnels are commonly excavated using drilling and blasting methods, and the surrounding rock is greatly affected by the vibration of surrounding hole blasting. To study the influence of the number of free surfaces on the energy distribution and attenuation law of surrounding hole blasting vibration signals, on-site experiments and numerical simulation experiments were conducted. The research results indicate that the higher the number of free surfaces, the smaller the peak vibration velocity. The longitudinal Fourier main frequency decreases with the distance from the monitoring point. The more free surface, the greater the centroid frequency and zero crossing frequency. In addition, numerical simulation shows that the degree of rock fragmentation after blasting increases with the increase of the number of free surface of rock
Research advances in drug therapy of endometriosis
Endometriosis is one of the most common benign gynecological disorders in reproductive-aged women. The major symptoms are chronic pelvic pain and infertility. Despite its profound impact on women’s health and quality of life, its pathogenesis has not been fully elucidated, it cannot be cured and the long-term use of drugs yields severe side effects and hinders fertility. This review aims to present the advances in pathogenesis and the newly reported lead compounds and drugs managing endometriosis. This paper investigated Genetic changes, estrogen-dependent inflammation induction, progesterone resistance, imbalance in proliferation and apoptosis, angiogenesis, lymphangiogenesis and neurogenesis, and tissue remodeling in its pathogenesis; and explored the pharmacological mechanisms, constitutive relationships, and application prospects of each compound in the text. To date, Resveratrol, Bay1316957, and bardoxifene were effective against lesions and pain in controlled animal studies. In clinical trials, Quinagolide showed no statistical difference with the placebo group; the results of phase II clinical trial of the IL-33 antibody have not been announced yet; clinical trial stage III of vilaprisan was suspended due to drug toxicity. Elagolix was approved for the treatment of endometriosis-related pain, but clinical studies of Elagolix for the pretreatment of patients with endometriosis to before In vitro fertilization treatment have not been fulfilled. The results of a clinical study of Linzagolix in patients with moderate to severe endometriosis-related pain have not been disclosed yet. Letrozole improved the fertility of patients with mild endometriosis. For endometriosis patients with infertility, oral GnRH antagonists and aromatase inhibitors are promising drugs, especially Elagolix and Letrozole
Antibacterial activity of water-phase extracts from bamboo shavings against food spoilage microorganisms
Water-phase extract of bamboo shavings (WEBS), by supercritical carbon dioxide extraction, was evaluated for its antimicrobial action against the range of food borne and food spoilage pathogens using agar disc diffusion assay in nutrient agar and Czapek Dox Agar media. The WEBS exhibited antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Aspergillus niger, Penicilliun citrinum and Saccharomyces cerevisiae with a concentration-dependent relationship. The minimum inhibitory concentrations (MICs) of the WEBS against the tested bacterial strains were found in the range of 4.9 - 32 mg/ml using the two-fold dilution method. Different heat treatment conditions have no significant influence on the antibacterial activity. Emodin was taken as the standard sample to test for the content of total anthraquinone compound and preliminarily verify its antibacterial mechanism, so as to lay a theoretical foundation for development of its natural preservatives.Key words: Water-phase extract of bamboo shavings (WEBS), antimicrobial activity, natural preservative
Pollutant Migration Pattern during Open-Pit Rock Blasting Based on Digital Image Analysis Technology
Previous studies have revealed that toxic gases and dust (smoke dust) are the most common pollutants generated by the blasting operations in open-pit mines, which might lead to a threat to the environment’s condition, health and safety, and properties protection around the blasting site. In order to deal with the problems, a pollution evaluation system was established based on the fractal dimension theory (Dbox(P)) and grayscale average algorithm (Ga) in digital image-processing technology to recognize and analyze the distributions of the smoke-dust cloud, and subsequently determine the pollution degrees. The computation processes of Dbox(P) and Ga indicate three fitted correlations between the parameters and diffusion time of smoke dust. Then, a pollution index (Pi) is put forward to integrate the global and local features of Dbox(P) and Ga, and develop a hazard classification mechanism for the blasting pollutants. Results obviously denote three diffusion stages of the pollutants, mainly including generation stage, cloud-formation stage, and diffusion stage. In addition, it has been validated that the proposed system can also be utilized in single-point areas within a whole digital image. Besides, there are variation trends of the thresholds T1 and T2 in binarization with the diffusion of pollutants. With this identification and evaluation system, the pollution condition of smoke dust can be obviously determined and analyzed
Development of a Procedure for Prioritizing Intersection Improvement Projects Considering Safety and Operational Factors
To utilize the limited budget allocated for intersection improvements more effectively, transportation agencies need to develop an annual plan that can prioritize intersection improvement projects and select the projects that can maximize the budget utilization for implementing. The current method used in Florida is based solely on the ratio of improvement of safety performance to project costs. This article presents a new decision-making supporting procedure, namely, Multi-Layer Prioritization (MLP), to prioritize intersection improvement projects considering safety and operational factors rather than considering safety factor only. The new procedure combines the successive ranking methodology and the hierarchical clustering algorithm to prioritize projects in several layers with which various factors associate in terms of relative importance of the factors. The consideration of safety and operational factors in the new procedure can provide more effective prioritization results, whereas the successive structure of the new procedure offers flexibility to increase or change considering factors. Three factors-benefit-cost ratio for safety performance, reduction in average control delay, and existing control delay-are utilized in the proposed procedure. And a case study was also conducted to demonstrate the new procedure using intersection improvement projects collected in Florida
Modeling Impacts of Access Designs on Injury Severity at Midblock Segments of Urban Multilane Highways Using Heterogeneous Choice Regression
This paper presents results of a study that developed a statistical model to evaluate impacts of six types of access design on crash injury severity at midblock segments on urban multilane highways. A heterogeneous choice model was developed in this study to identify the significant factors contributing to crash injury severity and to quantify the impacts of access design on crash injury severity at midblock segments on urban multilane highways. For model development, a total of 153 access points with different access design were selected from Florida state roads and 1830 crashes occurred in these access points for three years (2008-2010) were collected for modeling. Results of this study shows at four-leg access points, changing full median opening to directional median opening will decrease the probability of severe injury or fatality by 2.44% and that of no-capacitating injury by 8.5%. And at three-leg access points, replacing full median opening with direction median opening will not influence crash injury severity significantly. Closing median opening will decrease injury severity compared to other access designs. Other significant factors contributing to injury severity at access points were also identified as crash type, left-turn storage space on major roads, pavement surface width, outside shoulder width, median width, speed limit, AADT, high density residential area, day light condition, age of driver at-fault, and truck involvement. The results are expected to assist transportation agencies in implementing proper countermeasures to improve safety performance at midblock segments of urban multilane highways
Protective Effect of Agaricus brasiliensis on STZ-Induced Diabetic Neuropathic Pain in Rats
Objective. The present investigation examined the neuroprotective effect of Agaricus brasiliensis (AbS) against STZ-induced diabetic neuropathic pain in laboratory rats. STZ-induced diabetic rats were administered orally with AbS. Body weight, serum glucose, and behavioral parameters were measured before and at the end of the experiment to see the effect of AbS on these parameters. After 6 weeks of treatments, all animals were sacrificed to study various biochemical parameters. Treatment with AbS 80 mg/kg in diabetic animals showed significant increase in body weight, pain threshold, and paw withdrawal threshold and significant decrease in serum glucose, LPO and NO level, Na-K-ATPase level, and TNF-and IL-1 level as compared to vehicle treated diabetic animals in dose and time dependent manner. AbS can offer pain relief in PDN. This may be of potential benefit in clinical practice for the management of diabetic neuropathy
Protective Effect of Agaricus brasiliensis on STZ-Induced Diabetic Neuropathic Pain in Rats
Objective. The present investigation examined the neuroprotective effect of Agaricus brasiliensis (AbS) against STZ-induced diabetic neuropathic pain in laboratory rats. STZ-induced diabetic rats were administered orally with AbS. Body weight, serum glucose, and behavioral parameters were measured before and at the end of the experiment to see the effect of AbS on these parameters. After 6 weeks of treatments, all animals were sacrificed to study various biochemical parameters. Treatment with AbS 80 mg/kg in diabetic animals showed significant increase in body weight, pain threshold, and paw withdrawal threshold and significant decrease in serum glucose, LPO and NO level, Na-K-ATPase level, and TNF-alpha. and IL-1 beta. level as compared to vehicle treated diabetic animals in dose and time dependent manner. AbS can offer pain relief in PDN. This may be of potential benefit in clinical practice for the management of diabetic neuropathy