Laboratory Evaluation of Performance Recovery of Aged SBS-modified Asphalt Using Regenerants with Different Base Oil Components

In this study,the regenerative effects of different regenerants on aged SBS-modified asphalt from different perspectives were investigated,including their conventional properties,viscoelastic behavior,creep-related properties,and micromorphology.Base oils composed of different proportions of aromatic and saturated hydrocarbons as well as the styrene-butadiene-styrene(SBS)restorer were used to prepare the regenerants.The results showed that the components of the base oil of the regenerant played a crucial role in determining the characteristics and performance of the recycled SBSmodified asphalt.Regenerants containing a high proportion of aromatics dissolved the hard segment in the SBS restorer,thereby delaying the effect of a reduction in the regenerants on the performance of the aged asphalts at a high temperature.Regenerants containing a high proportion of saturates dissolved the soft segment in the SBS restorer to enhance the lowtemperature performance of the recycled asphalts.In addition,the stress sensitivity of the recycled asphalts increased with the fraction of aromatics in the regenerant.As the aromatic content of the base oil components of the regenerants increased and their saturate content decreased,the state of dispersion of the SBS phase in the recycled SBS-modified asphalts improved.The optimal content of aromatics in the base oil of the regenerants should be set in the range of 33%to 47%to ensure the adequate performance of the recycled asphalts and a high efficiency of the SBS restorer.

A United States Population-Based Study on Clinical Outcomes Following Primary Carotid Endarterectomy: Who and When?

Introduction: Carotid Endarterectomy (CEA) is widely recognized as effective in significantly reducing the risk of recurrent stroke emanating from extracranial carotid atherosclerosis and approximately 140,000 carotid endarterectomies are performed annually in the United States (US). As such, data are scarce on the prevalence and clinical outcomes of CEA across different age groups. This study aimed to determine and analyze the prevalence, demographic and clinical outcomes of CEA across six decades of life. Methods: Data on 40,276,240 patients were abstracted from discharge data obtained from the Nationwide Inpatient Sample (NIS) database, a part of the Healthcare Cost and Utilization Project (HCUP) of the Agency for Healthcare Research and Quality (2004-2008). Demographic and clinical characteristics of patients undergoing CEA as the primary procedure were abstracted including age, gender, elective or non-elective admission, comorbidities, Length of Stay (LOS), secondary procedures, NIS severity of illness and risk of mortality class, complications and mortality. CEA outcomes were compared across six decades of life starting at age 41. Categorical variables were compared using the Chi-square test, and the Student’s t-test was used to compare continuous variables. Results: 118,947 patients who underwent CEA as their primary procedure were identified. Caucasians accounted for 67.1% of the population. The overall mean age was 71.2 ± 9.5 years, with a Male: Female ratio of 1.3:1. Nineteen percent of patients had non-elective admission, with the highest percentage (29.5%) in those >91 years old. Over three percent of patients had a prior stroke. The overall number of CEA performed peaked in the 8th decade of life (38.4%). The most common co-morbidities were hypertension, diabetes mellitus, and chronic pulmonary disease. Mean LOS was 3.3 days. Forty-two percent of all cases were performed in a teaching hospital, with the percentage increasing with advancing age. The overall mortality and stroke rates were 0.4% and 0.9%, respectively, and these rates were highest in the oldest patients (>91 years). The overall myocardial infarction rate was 0.8% which was highest incidence in the 7th and 9th decades (1.1%). On multivariate analysis, age >80 years (Odds Ratio (OR), 2.9;95% Confidence Interval (CI), 1.1 - 8.0), Non-white race (OR, 1.7;CI, 1.1 - 2.7), Charlson co-morbidity index score of 1 - 5 (OR, 1.7;CI, 1.3 - 2.4), carotid artery stenosis with stroke at presentation (OR, 1.7;CI, 1.1 - 2.5), Congestive Heart Failure (CHF) (OR, 3.7;CI, 2.8 - 4.8) and renal failure (OR, 2.2;CI, 1.6 - 3.1) were independent risk factors associated with increased CEA mortality. Conclusions: The percent of patients over 80 years is the fastest-growing segment of the US population, and CEA is an increasingly commonly procedure in elderly patients with a low mortality rate across all age groups. On a population level age >80, non-Caucasian race, the presence of specific co-morbidities (i.e., Stoke at presentation, congestive heart failure, renal failure), and a high Charlson co-morbidity index score are independent predictors of an increased CEA related mortality.

Impact of endoscopically minimal involvement on IL-8 mRNA expression in esophageal mucosa of patients with non-erosive reflux disease

AIM:Little has been known about the pathogenesis of non- erosive reflux disease(NERD).Recent studies have implicated interleukin 8(IL-8)in the development and progression of gastroesophgeal reflux disease(GERD).The purpose of this study was to determine IL-8 RNA expression levels in NERD patients with or without subtle mucosal changes. METHODS:We studied 26 patients with NERD and 13 asymptomatic controls.Biopsy sample was taken from the esophagus 3 cm above the gastroesophageal junction and snap frozen for measurement of IL-8 mRNA levels by real-time quantitative polymerase chain reaction(PCR).We also examined mRNA expression of IL-8 receptors,CXCR-1 and -2 by reverse transcriptase PCR.The patients were endoscopically classified into grade M(mucosal color changes without visible mucosal break)and N(neither minimal involvement nor mucosal break)of the modified Los Angeles classification. RESULTS:The relative IL-8 mRNA expression levels were significantly higher in esophageal mucosa of NERD patients than those in esophageal mucosa of the controls.There was a significant difference in IL-8 mRNA levels between grades M and N.The CXCR-1 and -2 mRNAs were constitutively expressed in esophageal mucosa.CONCLUSION: Our results suggest that high IL-8 levels in esophageal mucosa may be involved in the pathogenesis of NERD through interaction with its receptors. NERD seems to be composed of a heterogeneous population in terms of not only endoscopically minimal involvement but also immune and inflammatory processes.

夏商周青铜器铅同位素示踪研究数据库的构建

A data base of lead isotope ratio of ancient Chinese bronzes is set up. There are 2 888 members, including bronze objects, casting remains, and related ores, etc. in the file. The file contents of data base are made from analysis work on Chinese bronze previously carried out in several laboratories in China, Japan and USA. The main body of the file contents is formed from records, analysis data, reference documents, and images. The data base is designed for sharing information in provenance study on raw metal material for bronze production in China Bronze Age.

Expression of liver cancer associated gene HCCA3

AIM: To study and clone a novel liver cancer related gene, and to explore the molecular basis of liver cancer genesis. METHODS: Using mRNA differential display polymerase chain reaction (DDPCR), we investigated the difference of mRNA in human hepatocellular carcinoma (HCC) and paired surrounding liver tissues, and got a gene probe. By screening a human placenta cDNA library and genomic homologous extend, we obtained a full-length cDNA named HCCA3. We analyzed the expression of this novel gene in 42 pairs of HCC and the surrounding liver tissues, and distribution in human normal tissues by means of Northern blot assay. RESULTS: A full-length cDNA of liver cancer associated gene HCCA3 has been submitted to the GeneBank nucleotide sequence databases (Accession No. AF276707). The positive expression rate of this gene was 78.6% (33/42) in HCC tissues, and the clinical pathological data showed that the HCCA3 was closely associated with the invasion of tumor capsule (P=0.023) and adjacant small metastasis satellite nodules lesions (P=0.041). The HCCA3 was widely distributed in the human normal tissues, which was intensively expressed in lungs, brain and colon tissues, while lowly expressed in the liver tissues. CONCLUSION: A novel full-length cDNA was cloned and differentiated, which was highly expressed in liver cancer tissues. The high expression was closely related to the tumor invasiveness and metastasis,that may be the late heredited change in HCC genesis.

hOGG1 Ser326Cys polymorphism modifies the significance of the environmental risk factor for colon cancer

AIM:To determine the association of hOGG1 (8-oxoguanine glycosylase I,OGG1) polymorphism of Ser326Cys substitution with colon cancer risk and possible interaction with known environmental risk factors. METHODS:A case-control study with 125 colon cancer cases and 247 controls was conducted, RESULTS:There was no major difference in Ser326Cys genotype distribution between cases and controls.The meat intake tended to increase the odds ratio for colon cancer with an OR of 1.72 (95 % confidence interval;CI=1.12-2.76). Such tendency was more prominent in Cys/Cys carriers (OR=4.31,95 % CI=1.64-11.48),but meat intake was not a significant risk factor for colon cancer in Ser/Ser or Ser/ Cys carriers.The OR for colon cancer was elevated with marginal significance in smokers who were Cys/Cys carriers (OR=2.75,95 % CI=1.07-7.53) but not in Ser/Ser or Ser/ Cys carriers. CONCLUSION:These results suggest that the hOGG1 Ser326Cys polymorphism is probably not a major contributor to individual colon cancer susceptibility overall,but the Cys/ Cys genotype may alter the impact of some environmental factors on colon cancer development.

Microstructure and mechanical properties of extruded Mg-6.5Gd-1.3Nd-0.7Y-0.3Zn alloy

The Mg-6.5Gd-1.3Nd-0.7Y-0.3Zn alloy ingot and sheet were prepared by casting and hot extrusion techniques,and the microstructure,age hardening behavior and mechanical properties were investigated.The results show that the as-cast alloy mainly containsα-Mg solid solution and compounds of Mg5RE and Mg24RE5(RE=Gd,Y and Nd)phases.The grain size is refined after hot extrusion,and the Mg5RE and Mg24RE5 compounds are broken during the extrusion process.The extruded alloy exhibits remarkable age hardening response and excellent mechanical properties in the peak-aging state.The ultimate tensile strength,yield strength and elongation are 310 MPa,201 MPa and 5.8%at room temperature,and 173 MPa,133 MPa and 25.0%at 300℃,respectively.

Partial Availability and RGBI Methods to Improve System Performance in Different Interval of Time: The Drill Facility System Case Study

The main objective of this study is to propose a methodology to define the operational availability for a system in different interval of time based on Monte Carlo simulation. In addition, it is also an objective to identify critical equipment in such interval of time and define when carrying out inspections to detect and prevent failures. Nowadays, many software packages which apply Monte Carlo simulation based on reliability diagram block do not show the operational availability defined by interval of time. In most of cases, there’s no result that shows how system performs in specific interval of time. Depending on situation, it’s important to define the operational availability by different interval of time in order to follow up system performance along time. In order to solve such problem, it is proposed the “partial availability methodology” based on system age. Indeed, such method regards equipment age based in different period of time that will results in Partial Availability. That means, as instance, in case of two years of simulation there will be the cumulative operational availability and partial operational availability results for first and second years for example. Therefore, it is also important to define the inspection time in each interval of time (year) in order to detect possible equipment failure and define preventive maintenance to avoid such failures that will be performed by RGBI method. In order to show such methodologies, it will be carried out a drill facility case study which is required to define operational availability of the system on the first and second years as well as inspection time.

Long-term follow-up results of dural reconstruction without bone graft at anterior skull-base defects

OBJECTIVE: To clarify whether it is necessary to reconstruct bone defects at the anterior skull base. METHODS: A long-term follow-up study of 50 patients with anterior skull-base defects in which the dura was reconstructed without bone grafts was conducted. CT and MRI examinations were taken periodically after surgery. RESULTS: The ordinates of the bone defects averaged 3.5 cm (range, 2 - 6 cm), and the abscissas averaged 2.8 cm (range, 2 - 5 cm). The abscissas of the bone defects measured 2 - 3 cm in 38 patients, 3 - 4 cm in 10 patients, and 4 - 5 cm in 2 patients. The follow-up ranged from 3 months to 5 years (average, 2 years). CONCLUSIONS: At normal intracranial pressure, if the dura mater is repaired properly at the skull-base defects and reinforced with a pedicled pericranial flap, encephalomeningocele and cerebrospinal fluid (CSF) leakage can be prevented. It may not be necessary to make free bone grafts when the size of the cranial base bone defect is smaller than 4 cm.