| 1 | Old vs new: Risk factors predicting early onset colorectal cancer显示文摘BACKGROUND Colorectal cancer(CRC)is the second leading cause of all cancer related deaths in the United States and Europe.Although the incidence has been decreasing for individuals’≥50,it has been on the rise for individuals<50.AIM To identify potential risk factors for early-onset CRC.METHODS A population-based cohort analysis using a national database,Explorys,screened all patients with an active electronic medical record from January 2012 to December 2016 with a diagnosis of CRC.Subgroups were stratified based on age(25–49 years vs≥50 years).Demographics,comorbidities,and symptom profiles were recorded and compared between both age groups.Furthermore,the younger group was also compared with a control group consisting of individuals aged 25-49 years within the same timeframe without a diagnosis of CRC.Twentydata points for CRC related factors were analyzed to identify potential risk factors specific to early-onset CRC.RESULTS A total of 68860 patients were identified with CRC,of which 5710(8.3%)were younger than 50 years old,with 4140(73%)between 40-49 years of age.Multivariable analysis was reported using odds ratio(OR)with 95%CI and demonstrated that several factors were associated with an increased risk of CRC in the early-onset group versus the later-onset group.These factors included:African-American race(OR 1.18,95%CI:1.09-1.27,P<0.001),presenting symptoms of abdominal pain(OR 1.82,95%CI:1.72-1.92,P<0.001),rectal pain(OR 1.50,95%CI:1.28-1.77,P<0.001),altered bowel function(OR 1.12,95%CI:1.05-1.19,P=0.0005),having a family history of any cancer(OR 1.78,95%CI:1.67-1.90,P<0.001),gastrointestinal(GI)malignancy(OR 2.36,95%CI:2.18-2.55,P<0.001),polyps(OR 1.41,95%CI:1.08-1.20,P<0.001),and obesity(OR 1.14,95%CI:1.08-1.20,P<0.001).Comparing the early-onset cohort versus the control group,factors that were associated with an increased risk of CRC were:male gender(OR 1.34,95%CI:1.27-1.41),P<0.001),Caucasian(OR 1.48,95%CI:1.40-1.57,P<0.001)and African-American race(OR 1.25,95%CI:1.17-1.35,P<0.001),presenting symptoms of abdominal pain(OR 4.73,95%CI:4.49-4.98,P<0.001),rectal pain(OR 7.48,95%CI:6.42-8.72,P<0.001),altered bowel function(OR 5.51,95%CI:5.19-5.85,P<0.001),rectal bleeding(OR 9.83,95%CI:9.12-10.6,P<0.001),weight loss(OR 7.43,95%CI:6.77-8.15,P<0.001),having a family history of cancer(OR 11.66,95%CI:10.97-12.39,P<0.001),GI malignancy(OR 28.67,95%CI:26.64-30.86,P<0.001),polyps(OR 8.15,95%CI:6.31-10.52,P<0.001),tobacco use(OR 2.46,95%CI:2.33-2.59,P<0.001),alcohol use(OR 1.71,95%CI:1.62-1.80,P<0.001),presence of colitis(OR 4.10,95%CI:3.79-4.43,P<0.001),and obesity(OR 2.88,95%CI:2.74-3.04,P<0.001).CONCLUSION Pending further investigation,these potential risk factors should lower the threshold of suspicion for early CRC and potentially be used to optimize guidelines for early screening. | Aslam R Syed Payal Thakkar Zachary D Horne Heitham Abdul-Baki Gursimran Kochhar Katie Farah Shyam Thakkar | 2019 | World Journal of Gastrointestinal Oncology2019，11，11： | 6 |
| 7 | Three-degree-of-freedom Parallel Manipulator to Track the Sun for Concentrated Solar Power Systems显示文摘In concentrated solar power(CSP) generating stations, incident solar energy is reflected from a large number of mirrors or heliostats to a faraway receiver. In typical CSP installations, the mirror needs to be moved about two axes independently using two actuators in series with the mirror effectively mounted at a single point. A three degree-of-freedom parallel manipulator, namely the 3-RPS parallel manipulator, is proposed to track the sun. The proposed 3-RPS parallel manipulator supports the load of the mirror, structure and wind loading at three points resulting in less deflection, and thus a much larger mirror can be moved with the required tracking accuracy and without increasing the weight of the support structure. The kinematics equations to determine motion of the actuated prismatic joints in the 3-RPS parallel manipulator such that the sun's rays are reflected on to a stationary receiver are developed. Using finite element analysis, it is shown that for same sized mirror, wind loading and maximum deflection requirement, the weight of the support structure is between 15% and 60% less with the 3-RPS parallel manipulator when compared to azimuth-elevation or the target-aligned configurations. | ASHITH SHYAM R B GHOSAL A | 2015 | Chinese Journal of Mechanical Engineering2015，28，4： | 1 |
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