Micro-computerized Three-dimensional Reconstruction of the Palmar Arteries and Its Clinical Significance

Thirty adult upper extremities were used to study the arteries of the hand byangiography,cross-sectional dissection and three-dimensional reconstruction withmicrocomputer.The arterial skeleton of the palm was composed of superficial,deep anddorsal planes.There were three main anastomotic pathways between the radial and ulnararteries or their branches in the radio-ulnar direction,while in the palmar dorsal dirce-tion there were three anastomotic zones between the palrnar and dorsal arterial plancs.The branches of the deep palmar arch radiated distally,proximally,palmarly anddorsally,so that the arch acted as the center of the arterial network of the hand.Thetransverse arterial allocations in the carpo-metacarpal segment of the palm were four intypes,but in the mid-palmar and metacarpo-phalangcal segments were three only.Accord-ing to the sources,cross-sectional area,irrigation territories and anastomoses of the ar-teries in each segment,the clinical significance in the rcplantation of the amputatcd palmshas been

Three-Point Bending Test and Crack Detection by Acoustic Emission on Different Spring Steel Wires with Different Crystallographic Textures

In the production of compression springs,high forming velocities and grades of deformation during winding and setting may induce cracks that can lead to failure causing risks of an accident and damage.The AE(acoustic emission)technology,a non-destructive monitoring method,can detect acoustic signals reflected from cracks.To establish this method in the production of technical springs,it was necessary,to find out whether the AE signal is influenced by material properties,phase fractions distribution from tempered martensite,retained austenite,and microstructure including crystallographic texture.In addition,it was investigated to what extent the detected AE signal can be useful to separate between an actual crack and other material responses.Within an in-situ three-point bending test with the AE technology,macro-and micro-crack-typical AE signals were detected for five different spring steel wires(SH,VDSiCr,and FDSiCr according to EN-10270-1 and EN-10270-2).The relative energy related to the initiation,propagation,and growth of cracks caused by mechanical stress was measured using a piezoelectric sensor.If a crack AE signal appeared for the first time,the bending tests were stopped immediately.The results show that the frequency spectrum combined with the intensity of the acoustic signals generated during crack growth depends on the material properties and the crystallographic texture.Furthermore,it could be shown that it is possible to differentiate between micro-crack-typical AE signals and other signals that result from different material responses.

Bone Protection Effects of A Novel Chinese Herbal Formula,Taikong Yangxin Prescription(太空养心方),in Hindlimb Unloaded Rats against Bone Deterioration

ABSTRACT Objective： To investigate the protective effects of a Chinese herbal formula, Taikong Yangxin Prescription （太空养心方,TKYXP） against bone deterioration in a hindlimb unloaded （tail-suspension） rat model. Methods： Thirty-two male Sprague-Dawley rats were divided into 4 groups： tail-suspension group fed with 2.5 g·kg^-1·day^-1 of TKYXP extract （high dose）, tail-suspension group fed with 1.25 g·kg^-1·day^-1 （low dose）, tail-suspended group treated with water placebo （placebo control group） and non tail-suspended group. The effects of TKYXP on bone were assessed using peripheral quantitative computed tomography （pQCT）, micro- computerized tomography （micro-CT） and three-point bending biomechanical test on the femur in vivo. Results： TKYXP had a significant protective effect against bone loss induced by tail-suspension on day 28, as shown in the reduction in bone mineral density （BMD） loss, preservation of bone micro-architecture and biomechanical strength. The administration ofhigh dose TKYXP could significantly reduce the total BMD loss by 4.8% and 8.0% at the femur and tibia regions, respectively, compared with the placebo control group （P〈0.01） on day 28. Its bone protective effect on the femur was further substantiated by the increases of the trabecular BMD （by 6.6%）, bone volume fraction （by 20.9%）, trabecular number （by 9.5%） and thickness （by 11.9%） as compared with the placebo control group. Conclusion： TKYXP may protect the bone under weightless influence from gradual structural deterioration in the tail-suspension model.