Application of terrain-vehicle mechanics for determination and prediction of mobility performance of autonomous wheeled mobile robot （AWMR） in rough terrain is a new research area currently receiving much attention ...Application of terrain-vehicle mechanics for determination and prediction of mobility performance of autonomous wheeled mobile robot （AWMR） in rough terrain is a new research area currently receiving much attention for both terrestrial and planetary missions due to its significant role in design, evaluation, optimization, and motion control of AWMRs. In this paper, decoupled closed form terramechanics considering important wheel-terrain parameters is applied to model and predict traction. Numerical analysis of traction performance in terms of drawbar pull, tractive efficiency, and driving torque is carried out for wheels of different radii, widths, and lug heights, under different wheel slips. Effects of normal forces on wheels are analyzed. Results presented in figures are discussed and used to draw some conclusions. Furthermore, a multiobjective optimization （MOO） method for achieving optimal mobility is presented. The MOO problem is formulated based on five independent variables in- eluding wheel radius r, width b, lug height h, wheel slip s, and wheel rotation angle 0 with three objectives to maximize drawbar pull and tractive efficiency while minimizing the dynamic traction ratio. Genetic algorithm in MATLAB is used to obtain opti- mized wheel design and traction control parameters such as drawbar pull, tractive efficiency, and dynamic traction ratio required for good mobility performance. Comparison of MOO results with experimental results shows a good agreement. A method to apply the MOO results for online traction and mobility prediction and control is discussed.展开更多
To the Editor:Noonan syndrome (NS)is a common genetic multisystem disorder caused by aberrant signal flux through mitogen-activated protein kinase (Ras-MAPK) and has an estimated prevalence of 1 in 1000-2500[1]. It wa...To the Editor:Noonan syndrome (NS)is a common genetic multisystem disorder caused by aberrant signal flux through mitogen-activated protein kinase (Ras-MAPK) and has an estimated prevalence of 1 in 1000-2500[1]. It was characterized by Jacqueline Noonan,who reported nine patients with pulmonary valve stenosis,small stature, hypertelorism,mild intellectual disability,webbed neck, undescended testes,and skeletal malformations[2], The lymphatic disorders are rare,it can happen at any age but most instances happen at birth,which are known to be particularly associated with NS,though it has not been well characterized to date.Gene mutations identified in individuals with the NS,regulate impertinently the Ras/ MAPK signal transduction pathway and they can currently explain 70 %of the NS cases.Therefore,it is very important for genetic counseling and life management.[2] Here,we reported a rare Noonan syndrome 9 patient in Asian with significant,persistent and progressive bilateral lower limb dysplasia.展开更多
The International Society of Reproductive Genetics(ISRG)assembled a workgroup made up of clinicians,clinical laboratory directors,and scientists for the purpose of creating the guidelines for preimplantation genetic t...The International Society of Reproductive Genetics(ISRG)assembled a workgroup made up of clinicians,clinical laboratory directors,and scientists for the purpose of creating the guidelines for preimplantation genetic testing(PGT).The most up-to-date information and clinical insights for the optimal PGT practice were incorporated in these guidelines.Recommendations are provided for embryologists,medical geneticists,clinical laboratorians,and other healthcare providers to improve the wellbeing of patients seeking assisted reproductive treatment and their offspring.展开更多
Objective::To evaluate the clinical utility of noninvasive prenatal screening(NIPS)for fetuses with congenital heart disease(CHD)and impact of NIPS results on pregnancy outcome.Methods::This was a retrospective study ...Objective::To evaluate the clinical utility of noninvasive prenatal screening(NIPS)for fetuses with congenital heart disease(CHD)and impact of NIPS results on pregnancy outcome.Methods::This was a retrospective study of pregnant women with fetuses diagnosed with CHDs by sonographic examination,who willing to underwent NIPS as a side-test for fetal aneuploidies.From August 2016 to October 2017,in the sonographic examination center of Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region.NIPS was offered to 117 women,19-32 years old,who carried fetuses with CHD diagnosed by fetal ultrasound(mean gestational age=24 weeks).The pregnancy outcomes were followed-up.Results::NIPS positive rate in our pregnancies with CHD fetuses’cohort was 11.1%(13/117),and the positive predictive value for aneuploidies is 85.7%(6/7).In the NIPS positive group(n=13),all pregnancies terminated,76.9%(10/13)of those decisions were made on ultrasound finding alone.In the NIPS negative group(n=104),2 lost follow-up,79 pregnancies terminated,among which 77.2%(61/79)of the decision was made by ultrasound results alone.Twenty-three pregnancies continued and 78.3%of those fetuses carried single type CHD.In terminated pregnancies that did not considered NIPS results(71/115),73.2%(52/71)of those carried fetuses with two or more types of CHDs.Conclusion::NIPS can detect common aneuploidy associated with CHD with high positive predictive value and screening yield.The NIPS result played certain meaningful roles in determining pregnancy outcomes,particularly for fetus with simplex CHD;yet the parents’decision of pregnancy was mainly made based on ultrasound findings.展开更多
基金Project supported by the National Natural Science Foundation of China(No. 60775060)the Natural Science Foundation of Heilongjiang Province of China (No. F200801)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education (Nos. 200802171053 and 20102304110006)the Harbin Science and Technology Innovation Talents Special Fund (No. 2012RFXXG059),China
文摘Application of terrain-vehicle mechanics for determination and prediction of mobility performance of autonomous wheeled mobile robot （AWMR） in rough terrain is a new research area currently receiving much attention for both terrestrial and planetary missions due to its significant role in design, evaluation, optimization, and motion control of AWMRs. In this paper, decoupled closed form terramechanics considering important wheel-terrain parameters is applied to model and predict traction. Numerical analysis of traction performance in terms of drawbar pull, tractive efficiency, and driving torque is carried out for wheels of different radii, widths, and lug heights, under different wheel slips. Effects of normal forces on wheels are analyzed. Results presented in figures are discussed and used to draw some conclusions. Furthermore, a multiobjective optimization （MOO） method for achieving optimal mobility is presented. The MOO problem is formulated based on five independent variables in- eluding wheel radius r, width b, lug height h, wheel slip s, and wheel rotation angle 0 with three objectives to maximize drawbar pull and tractive efficiency while minimizing the dynamic traction ratio. Genetic algorithm in MATLAB is used to obtain opti- mized wheel design and traction control parameters such as drawbar pull, tractive efficiency, and dynamic traction ratio required for good mobility performance. Comparison of MOO results with experimental results shows a good agreement. A method to apply the MOO results for online traction and mobility prediction and control is discussed.
文摘To the Editor:Noonan syndrome (NS)is a common genetic multisystem disorder caused by aberrant signal flux through mitogen-activated protein kinase (Ras-MAPK) and has an estimated prevalence of 1 in 1000-2500[1]. It was characterized by Jacqueline Noonan,who reported nine patients with pulmonary valve stenosis,small stature, hypertelorism,mild intellectual disability,webbed neck, undescended testes,and skeletal malformations[2], The lymphatic disorders are rare,it can happen at any age but most instances happen at birth,which are known to be particularly associated with NS,though it has not been well characterized to date.Gene mutations identified in individuals with the NS,regulate impertinently the Ras/ MAPK signal transduction pathway and they can currently explain 70 %of the NS cases.Therefore,it is very important for genetic counseling and life management.[2] Here,we reported a rare Noonan syndrome 9 patient in Asian with significant,persistent and progressive bilateral lower limb dysplasia.
基金National Key Research and Development Program of China(2021YFC2700701,2021YFC2701002,2020YFA0804000,2018YFC1004901)National Natural Science Foundation of China(82171677,81901495,82088102,81971344,82171686,82071661)+6 种基金Clinical Research Project of Shanghai Municipal Health Commission(202140110)CAMS Innovation Fund for Medical Sciences(2019-I2M-5-064)International Science and Technology Collaborative Fund of Shanghai(18410711800)Collaborative Innovation Program of Shanghai Municipal Health Commission(2020CXJQ01)Shanghai Municipal Commission of Science and Technology Program(21Y21901002,22S31901500)Clinical Research Plan of SHDC(SHDC2020CR1008A)Shanghai Frontiers Science Research Base of Reproduction and Development,and Shanghai"Science and Technology Innovation Action Plan"Hong Kong,Macao,and Taiwan Science and Technology Cooperation Project(19410760100)
文摘The International Society of Reproductive Genetics(ISRG)assembled a workgroup made up of clinicians,clinical laboratory directors,and scientists for the purpose of creating the guidelines for preimplantation genetic testing(PGT).The most up-to-date information and clinical insights for the optimal PGT practice were incorporated in these guidelines.Recommendations are provided for embryologists,medical geneticists,clinical laboratorians,and other healthcare providers to improve the wellbeing of patients seeking assisted reproductive treatment and their offspring.
基金supported by the Guangxi Zhuang Autonomous Region Health Commission(project number S201543 and Z20190827)
文摘Objective::To evaluate the clinical utility of noninvasive prenatal screening(NIPS)for fetuses with congenital heart disease(CHD)and impact of NIPS results on pregnancy outcome.Methods::This was a retrospective study of pregnant women with fetuses diagnosed with CHDs by sonographic examination,who willing to underwent NIPS as a side-test for fetal aneuploidies.From August 2016 to October 2017,in the sonographic examination center of Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region.NIPS was offered to 117 women,19-32 years old,who carried fetuses with CHD diagnosed by fetal ultrasound(mean gestational age=24 weeks).The pregnancy outcomes were followed-up.Results::NIPS positive rate in our pregnancies with CHD fetuses’cohort was 11.1%(13/117),and the positive predictive value for aneuploidies is 85.7%(6/7).In the NIPS positive group(n=13),all pregnancies terminated,76.9%(10/13)of those decisions were made on ultrasound finding alone.In the NIPS negative group(n=104),2 lost follow-up,79 pregnancies terminated,among which 77.2%(61/79)of the decision was made by ultrasound results alone.Twenty-three pregnancies continued and 78.3%of those fetuses carried single type CHD.In terminated pregnancies that did not considered NIPS results(71/115),73.2%(52/71)of those carried fetuses with two or more types of CHDs.Conclusion::NIPS can detect common aneuploidy associated with CHD with high positive predictive value and screening yield.The NIPS result played certain meaningful roles in determining pregnancy outcomes,particularly for fetus with simplex CHD;yet the parents’decision of pregnancy was mainly made based on ultrasound findings.
