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This paper introduces the application for National Natural Science Foundation of China (NSFC) projects on mechanical sciences in the year 2021, analyses the characteristics of fund application in all branches of mechanics, especially biomechanics, points out some problems existing in fund application, and proposes several suggestions about the interdisciplinary research and development on biomechanics.
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Heat shock protein 70 (HSP70) family is one ofthe most conserved proteinin evolutionand plays critical,role in proteostasis.HSP70 is becoming an interesting target for multiple diseases such as cancer and Alzheimer's disease.There are many drugs targeted to HSP70 in preclinical study.In this review,the classification,the structure,the function of HSP70,and the drugs of the HSP70 family are reviewed.
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Objective To investigate the value of 3D-TEE,2D-TEE,CTA and X-ray contrast in assessing left atrial appendage (LAA) shape,size and guidance for the choice of occlusion.Methods Forty-three cases of left atrial fibrillation who were referred for LAA closure were performed TEE to measure the opening maximum diameter,and maximum depth of 2D-TEE at 0°,45°,90° and 135°.When LAA showed most clearly,the opening maximum and minimum diameter of LAA were measured by using 3D-ROOM mode,and the results were compared with those measured by CTA and X-ray contrast.Results There was no significant difference for opening maximum diameter of LAA measured by 3D-TEE,2D-TEE and X-ray contrast (all P＞0.05),but that of CTA statistically larger than 3D-TEE,2D-TEE,X-ray contrast (all P＜0.01).There were significant difference between 2D-TEE at 90°,135° and CTA,2D-TEE at 135° and X-ray contrast in assessing maximum depth of LAA (all P＜0.05).Opening maximum diameter of LAA measured by 3D-TEE was significantly correlated with each angle of 2D-TEE,CTA,and X-ray contrast (r=0.70-0.77,0.57,0.58,all P＜0.01),and the opening maximum diameter measured by 2D-TEE also correlated with CTA and X-ray contrast (r =0.57-0.71,0.45-0.51,all P＜0.01).Also the opening maximum diameter measured by 3D-TEE,2D-TEE,CTA and x-ray contrast were correlated with occluder size (r=0.93,0.70-0.77,0.57,0.47,all P＜0.01).Conclusion Compared with 2D-TEE,CTA and X-ray contrast,3D-TEE is more instructive for occluder selection.
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@#Ocotillol(3)and its epimer(4)have been synthesized from 20(S)-protopanaxatriol ［20(S)-PPT］ via two routes, and their formation mechanism has been speculated. Route 1: Compounds 3 and 4 were obtained from 20(S)-PPT by oxidation with m-CPBA at the yield of 44. 1% and 28. 6%, respectively. Route 2: Compounds 3 and 4 were prepared from 20(S)-PPT by acetylation, oxidation and saponification at the yield of 16. 4% and 16. 2%, respectively. The formation mechanism of compounds 3 and 4 is speculated as below: 1)The chemical environments of both sides of C24(25)double bond in 20(S)-PPT are different due to the existence of intramolecular hydrogen bond, which led to the different oxidation ratio of the two sides, and the different yields of compounds 3 and 4. 2)There is not intramolecular hydrogen bond in acetylated 20(S)-PPT, and the chemical environments of both sides of C24(25)double bond are similar, which resulted in almost equal yields of compounds 3 and 4 synthesized through oxidation with m-CPBA, intramolecular SN2 and saponification.
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Glycosylation is the key step of the synthesis of GM3 ,its reaction conditions are very harsh ,the stereoselec‐tivities are usually poor ,and the configuration of anomeric carbon is difficult to control .Whetherαglycosidic bond can be con‐structed efficiently in sialylation reactions is an important criteria used to evaluate the reaction quality .Studies of GM3 and de‐rivatives methods generally relates to following areas :the choice of the donor compounds and receptor compounds ,the control of stereoselectivity ,and the development of some new glycosidic reaction catalyst .In recent years ,important progress has been made in this research area .Now ,we predominately make a summary and review on the progress of methods for the synthesis of GM3 and derivatives .
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Objective To explore the excretion of the 20(S)-protopanaxatriol(PPT)and its metabolites ocotillol type epi?mers(M1 and M2)in urine,feces samples and the excretion of M1 and M2 in bile samples. Methods The concentration of PPT,M1 and M2 in urine,feces samples and the concentration of M1 and M2 in bile samples were determined by the LC-MS/MS methods with or without the hydrolization byβ-glucuronidase. Results After intragastric(ig)administration of PPT,the cumulative excretion rate for 72 h of PPT,M1 and M2 in feces were 14.88%,1.34%and 0.084%,respectively. With the hydrolization byβ-glucuronidase,the cumulative excretion rate for 72 h of PPT,M1 and M2 in feces were 14.77%,1.36%and 0.085%,respectively. However,the epimers and PPT were hardly detected in urine. After ig administration of M1 or M2,the accumulation excretion rate were 4.41%for M1 and 47.2%for M2 in feces,while both epimers were hardly detected in urine. After ig administration of M1 or M2,the 36 h cumulative bili?ary excretion rate was 3.01%for M1,and only 0.068%for M2. The 36 h cumulative biliary excretion rate of M1 was 8.80%after intra?venous administration ,while only 1.24%for M2. Conclusion After ig administration of PPT,a small amount of PPT and its metabo?lites(M1,M2)are excreted by the feces but little via urine ,and there are stereoselectivity differences in biliary excretion between M1 and M2.
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Antimicrobial peptides ( AMPs) are a kind of micromolecular peptides with antibacterial , antivirus and anti-tumor activities.Unlike conventional antibiotics , acquisition of resistance by a sensitive microbial strain against AMPs is surprisingly improbable .AMPs are not widely used clinically due to their toxicity , susceptibility to proteolysis and high manufacturing cost .Researchers have obtained some AMPs with high activity and low toxicity by structure modifications . The molecular design of AMPs as well as their development in the future are reviewed .
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Objective To evaluate the changes of left ventricular(LV) 3-dimension peak displacement (3D-D) during different cardiac pacing patterns. To provide a reliable mechanical data base for the optimization cardiac pacing. Methods Cardiac pacings in open-chest Beagle canine models( n = 10) were performed using three patterns[I, e. , right ventricular apical pacing (RVA-P), LV lateral pacing (LVL-P)and LV apical pacing(LVA-P)],3D full volumetric real-time imaging were acquired in a completed cardiac cycle. The 3D-D,3D-D peak time (3D-DTc) and the standard deviation of TC(3D-DTSD) were calculated and analyzed in different pacing patterns for difference and spatial correlationship. Results ① The 3D-D of LVL-P and LVA-P state decreased compared with BASE and RVA-P state, there were significant 3D-D difference of mid anterior,mid anteriorspetal, mid interior,mid posterior, mid lateral between LVL-P and BASE, RVA-P patterns( P ＜0.05). There were significant 3D-D difference of mid anterior,mid lateral,mid posterior between LVA-P and RVA-P patterns groups( P ＜0.05). There were significant 3D-D difference of all segments in apical level between LVL-P,LVA-P and BASE, RVA-P states( P ＜0.05). ② Corrected by the heart rate,the 3D-DTC of different cardiac pacing patterns were shorter than BASE state. ③ There were no significant 3D-DTSD difference between different cardiac pacings and BASE patterns. There were significant 3D-DTSD difference between RVA-P and LVA-P patterns (P ＜ 0.05). Conclusions LV mechanical activation and synchronization could be maintained during RVA-P rather than LVA-P and LVL-P. Echocardiographic study of left ventricular 3D-D can actually reveal myocardial mechanical state during different cardiac pacings and BASE patterns.
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Objective To assess longitudinal segmental myocardial strain(?),displacement(D) and the changes of the inner dimension of left ventricle(?L),and to establish their spatial correlationship during cardiac pacing and conductive block.Methods The standard apical four chamber view of left ventricle were acquired during cardiac pacing(n=12),right bundle branch block(RBBB,n=13) and sinus rhythm(n=14) using GE Vivid 7 dimension and the M3S probe with(4.0) MHz for the analysis of the longitudinal myocardial segmental(apical and basal segments) ? and D of left ventricle with two dimensional strain analysis software.The maximal and change longitudinal dimension of left ventricle was measured and calculated at end-diastole and end-systole respectively.The differences of the above parameters were compared and the spatial correlationships among them were analyzed.Results The peak ? of the septal basal segment during cardiac pacing was significant higher than that of the apical segment.There were significant differences in the peak D and(?D)(D_(basal)-D_(apical)) at lateral wall among sinus rhythm,RBBB and pacing group(P
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To provide necessary evidence for studying the pharmacological and clinical effectiveness of Styela clava,the quantities of 21 chemical elements in Styela clava were analysised.It was found that the quantities of several mineral elements in it were higher than that in sea water,which indicated Styela clava had a relatively high ability to concentrate mineral elements.