ObjectiveTo observe the effect of sport walking on heart and lungs functions in old women.MethodsForty-two old women aged from 60 to 69 had sport walking for 4 months; the speed and intensity were controlled according to their heart rate respectively. The indexes of respiration, circulation and rheoencephalography were measured before and after exercise.ResultsAfter exercise, blood-pumping function of heart improved obviously, stroke volume increased from (65.22±11.41)ml to (72.10± 10.78)ml, ejection fraction increased from (60.10±5.03)% to (68.78±6.25)%, while heart rate declined from (77.45±8.69) times/min to (7.89±8.21)times/min, capacity increased from (2.86±0.36)L to (3.34±0.53)L, and maximal voluntary ventilation for every minute increased from (96.14± 15.21)L to (114.02±16.01)L, significantly different compared with that before treatment ( P<0.01). The fluid time of rheoencephalography reduced from (0.171±0.058)s to (0.128±0.049)s ( P<0.01).ConclusionSport walking under proper intensity can improve the function of respiration and circulation system in old women, so it is a good way to keep health for the elders.

OBJECTIVE: To explore biomechanical characteristics of minimally invasive different screw fixations in treating Sanders typeⅡcalcaneal fractures. METHODS: Dicom data of calcaneus by CT scan were input into Mimics 21.0 software and Ansys15.0 software to construct three-dimensional finite element digital model of calcaneus;this model was input into UG NX 10.0 software, and calcaneus was cut according to Sanders classification to establish Sanders typeⅡ calcaneus model with posterior articular surface collapse;then simulated minimally invasive screw internal fixation after calcaneal fracture:a screw from posterior articular surface was used to outside-in fix sustentaculum tali, other 4 screws were used to fix calcaneus by different methods through calcaneal tuberosity, and 4 different calcaneal models were obtained. Under the same conditions, 4 types of internal fixation models were loaded respectively, and nonlinear finite element analysis was performed to calculate the stress distribution of different internal fixation models. RESULTS: Under the same condition of loading, the model 3 had smaller displacement value, maximum calcaneus displacement value and maximum equivalent stress value of the screw than other three internal fixation models, and the stress was more dispersed. CONCLUSION In minimally invasive screw internal fixation of calcaneus fracture, after 1 sustentaculum tali screw fixation, 2 screws crossed fix posterior articular surface from calcaneal tuberosity, 2 screws fix parallelly calcaneocuboid joint from calcaneal tuberosity are more suitable for biomechanical requirements, and could provide basic theory for clinical treatment.
Bone Screws ; Calcaneus/surgery* ; Finite Element Analysis ; Fracture Fixation, Internal ; Fractures, Bone/surgery* ; Humans ; Treatment Outcome

OBJECTIVE: To explore the cause for the failure of non-invasive prenatal testing (NIPT) and feasibility of repeated testing. METHODS: Clinical data, test results and pregnancy outcomes of 40 311 pregnant women who received NIPT test from January 2011 to December 2018 were reviewed. RESULTS: Among all the pregnant women, 1116 cases failed in the first test, 9 cases (0.81%) had fetal free DNA concentration lower than 4%, 663 cases (59.41%) were retested after the establishment of Z value gray area, and the remainder 444 cases (39.78%) needed to be retested after the blood collection due to the fetal free DNA concentration lower than 4%. After retesting, 1069 cases (95.78%) obtained effective NIPT results. The results showed that 53 cases were at high risk (6 cases for trisomy 21, 6 cases for trisomy 18, 13 cases for trisomy 13, 16 cases for sex chromosomal abnormality, 12 cases for chromosomal copy number variation). Forty-eight cases were selected for invasive prenatal diagnosis, and 2 cases of 47, XXY and 2 CNV were confirmed. A total of 47 cases (0.12%) did not obtain results because the concentration of fetal free DNA was lower than 4%. Only 16 cases (34%) chose invasive prenatal diagnosis. CONCLUSION Repeated detection of the gray area of Z value can reduce the false positive rate of NIPT and invasive prenatal diagnosis, and the feasibility of repeated detection is high. In the case of fetal free DNA concentration lower than 4%, the success rate of obtaining effective NIPT results by re-sampling and re-detection increases with the increase of gestational age, but may delay the diagnosis for fetal aneuploidies. Therefore, personalized estimation should be made according to gestational age and clinical indications. It is suggested that pregnant women should choose invasive prenatal diagnosis when they have failed in the retest.