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Logic-in-memory (LIM) architecture holds great potential to break the von Neumann bottleneck. Despite the extensive research on novel devices, challenges persist in developing suitable engineering building blocks for such designs. Herein, we propose a reconfigurable strategy for efficient implementation of Boolean logics based on a hafnium oxide-based ferroelectric field effect transistor (HfO 2 -based FeFET). The logic results are stored within the device itself (in situ) during the computation process, featuring the key characteristics of LIM. The fast switching speed and low power consumption of a HfO 2 -based FeFET enable the execution of Boolean logics with an ultralow energy of lower than 8 attojoule (aJ). This represents a significant milestone in achieving aJ-level computing energy consumption. Furthermore, the system demonstrates exceptional reliability with computing endurance exceeding 10 8 cycles and retention properties exceeding 1000 s. These results highlight the remarkable potential of a FeFET for the realization of high performance beyond the von Neumann LIM computing architectures.

The environmental pollution caused by mineral exploitation and energy consumption poses a serious threat to ecological security and human health, particularly in resource-based cities. To address this issue, a comprehensive investigation was conducted on potentially toxic elements (PTEs) in road dust from different seasons to assess the environmental risks and influencing factors faced by Datong City. Multivariate statistical analysis and absolute principal component score were employed for source identification and quantitative allocation. The geo-accumulation index and improved Nemerow index were utilized to evaluate the pollution levels of PTEs. Monte Carlo simulation was employed to assess the ecological-health risks associated with PTEs content and source orientation. Furthermore, geo-detector and random forest analysis were conducted to examine the key environmental variables and driving factors contributing to the spatiotemporal variation in PTEs content. In all PTEs, Cd, Hg, and Zn exhibited higher levels of content, with an average content/background value of 3.65 to 4.91, 2.53 to 3.34, and 2.15 to 2.89 times, respectively. Seasonal disparities were evident in PTEs contents, with average levels generally showing a pattern of spring (winter) > summer (autumn). PTEs in fine road dust (FRD) were primarily influenced by traffic, natural factors, coal-related industrial activities, and metallurgical activities, contributing 14.9-33.9 %, 41.4-47.5 %, 4.4-8.3 %, and 14.2-29.4 % to the total contents, respectively. The overall pollution and ecological risk of PTEs were categorized as moderate and high, respectively, with the winter season exhibiting the most severe conditions, primarily driven by Hg emissions from coal-related industries. Non-carcinogenic risk of PTEs for adults was within the safe limit, yet children still faced a probability of 4.1 %-16.4 % of unacceptable risks, particularly in summer. Carcinogenic risks were evident across all demographics, with children at the highest risk, mainly due to Cr and smelting industrial sources. Geo-detector and random forest model indicated that spatial disparities in prioritized control elements (Cr and Hg) were primarily influenced by particulate matter (PM 10 ) and anthropogenic activities (industrial and socio-economic factors); variations in particulate matter (PM 10 and PM 2.5 ) and meteorological factors (wind speed and precipitation) were the primary controllers of seasonal disparities of Cr and Hg., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Vesicle transport plays important roles in plant tolerance against abiotic stresses. However, the contribution of a vesicle formation related protein CaSec16 (COPII coat assembly protein Sec16-like) in pepper tolerance to salt stress remains unclear. In this study, we report that the expression of CaSec16 was upregulated by salt stress. Compared to the control, the salt tolerance of pepper with CaSec16-silenced was compromised, which was shown by the corresponding phenotypes and physiological indexes, such as the death of growing point, the aggravated leaf wilting, the higher increment of relative electric leakage (REL), the lower content of total chlorophyll, the higher accumulation of dead cells, H 2 O 2 , malonaldehyde (MDA), and proline (Pro), and the inhibited induction of marker genes for salt-tolerance and vesicle transport. In contrast, the salt tolerance of pepper was enhanced by the transient overexpression of CaSec16. In addition, heterogeneously induced CaSec16 protein did not enhance the salt tolerance of Escherichia coli, an organism lacking the vesicle transport system. By yeast two-hybrid method, an ankyrin protein, CaANK2B, was identified as the interacting protein of CaSec16. The expression of CaANK2B showed a downward trend during the process of salt stress. Compared with the control, pepper plants with transient-overexpression of CaANK2B displayed increased salt tolerance, whereas those with CaANK2B-silenced exhibited reduced salt tolerance. Taken together, both the vesicle formation related protein CaSec16 and its interaction partner CaANK2B can improve the pepper tolerance to salt stress., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Minghui Lu reports was provided by National Natural Science Foundation of China. Minghui Lu reports was provided by Earmarked Fund for China Agriculture Research System. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Contamination, hazard level and source of 10 widely concerned potentially toxic metal(loid)s (PTMs) Co, As, Pb, Cr, Cu, Zn, Ni, Mn, Ba, and V in fine dust with particle size below 63 μm (FD63) were investigated to assess the environmental quality of college campuses and influencing factors. PTMs sources were qualitatively analyzed using statistical methods and quantitatively apportioned using positive matrix factorization. Probabilistic contamination degrees of PTMs were evaluated using enrichment factor and Nemerow integrated enrichment factor. Eco-health risk levels of content-oriented and source-oriented for PTMs were evaluated using Monte Carlo simulation. Mean levels of Zn (643.8 mg kg -1 ), Pb (146.0 mg kg -1 ), Cr (145.9 mg kg -1 ), Cu (95.5 mg kg -1 ), and Ba (804.2 mg kg -1 ) in FD63 were significantly larger than soil background values. The possible sources of the concerned PTMs in FD63 were traffic non-exhaust emissions, natural source, mixed source (auto repair waste, paints and pigments) and traffic exhaust emissions, which accounted for 45.7%, 25.4%, 14.5% and 14.4% of total PTMs contents, respectively. Comprehensive contamination levels of PTMs were very high, mainly caused by Zn pollution and non-exhaust emissions. Combined ecological risk levels of PTMs were low and moderate, chiefly caused by Pb and traffic exhaust emissions. The non-cancer risks of the PTMs in FD63 to college students fell within safety level, while the carcinogenic PTMs in FD63 had a certain cancer risks to college students. The results of source-specific health risk assessment indicated that Cr and As were the priority PTMs, and the mixed source was the priority pollution source of PTMs in FD63 from college campuses, which should be paid attention to by the local government., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Two-dimensional material-based field-effect transistors (2DM-FETs) are playing a revolutionary role in electronic devices. However, before electronic design automation (EDA) for 2DM-FETs can be achieved, it remains necessary to determine how to incorporate contact transports into model. Reported methods compromise between physical intelligibility and model compactness due to the heterojunction nature. To address this, quasi-Fermi-level phase space theory (QFLPS) is generalized to incorporate contact transports using the Landauer formula. It turns out that the Landauer-QFLPS model effectively overcomes the issue of concern. The proposed new formula can describe 2DM-FETs with Schottky or Ohmic contacts with superior accuracy and efficiency over previous methods, especially when describing non-monotonic drain conductance characteristics. A three-bit threshold inverter quantizer (TIQ) circuit is fabricated using ambipolar black phosphorus and it is demonstrated that the model accurately predicts circuit performance. The model could be very effective and valuable in the development of 2DM-FET-based integrated circuits., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Re-suspended surface dust (RSD) often poses higher environmental risks due to its specific physical characteristics. To ascertain the priority pollution sources and pollutants for the risk control of toxic metals (TMs) in RSD of medium-sized industrial cities, this study took Baotou City, a representative medium-sized industrial city in North China, as an example to systematically study TMs pollution in RSD. The levels of Cr (242.6 mg kg -1 ), Pb (65.7 mg kg -1 ), Co (54.0 mg kg -1 ), Ba (1032.4 mg kg -1 ), Cu (31.8 mg kg -1 ), Zn (81.7 mg kg -1 ), and Mn (593.8 mg kg -1 ) in Baotou RSD exceeded their soil background values. Co and Cr exhibited significant enrichment in 94.0 % and 49.4 % of samples, respectively. The comprehensive pollution of TMs in Baotou RSD was very high, mainly caused by Co and Cr. The main sources of TMs in the study area were industrial emissions, construction, and traffic activities, accounting for 32.5, 25.9, and 41.6 % of the total TMs respectively. The overall ecological risk in the study area was low, but 21.5 % of samples exhibited moderate or higher risk. The carcinogenic risks of TMs in the RSD to local residents and their non-carcinogenic risks to children cannot be ignored. Industrial and construction sources were priority pollution sources for eco-health risks, with Cr and Co being the target TMs. The south, north and west of the study area were the priority control areas for TMs pollution. The probabilistic risk assessment method combining of Monte Carlo simulation and source analysis can effectively identify the priority pollution sources and pollutants. These findings provide scientific basis for TMs pollution control in Baotou and constitute a reference for environmental management and protection of residents' health in other similar medium-sized industrial cities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Long non-coding RNAs (lncRNAs) have been certified to play vital biological functions in glioma and have received considerable attention in the recent literature. Nonetheless, the role of LINC01158 in glioma remains to be elucidated., Methods: qRT-PCR, western blot and GEPIA database were applied for reporting the expression of CENPK and LINC01158 in glioma and the correlation between LINC01158 and CENPK expression. EdU, colony formation, CCK-8, caspase-3 activity and TUNEL assays probed the impacts of LINC01158 on glioma cell growth. Subcellular fractionation and FISH assays revealed the cellular distribution of LINC01158. Luciferase reporter and RIP assays examined ceRNA network of LINC01158, CENPK and miR-6734-3p., Results: LINC01158 and CENPK were both overexpressed in glioma and a positive regulation of LINC01158 on CENPK was corroborated. LINC01158 served a pro-proliferative and anti-apoptotic part in glioma by sponging miR-6734-3p to augment CENPK., Conclusion: LINC01158 enhances CENPK by serving as sponge for miR-6734-3p to facilitate glioma development, proposing LINC01158 as a new player in glioma.

Purpose: As the factors affecting the efficacy of the bare-metal stent in the treatment of aneurysm with a visceral vessel attached were not fully understood, we aimed to discuss the effects of different characteristics of the stent on the hemodynamics and flexibility in the treatment of the aneurysm., Methods: Single-layer (with different strut widths) and multi-layer (with a different number of struts) stent models divided into three porosity groups, with porosities of 72.3, 60.5, and 52.4%, were modeled for a comparison of their hemodynamic isolation and flexibility performance via computational fluid dynamics and finite element methods., Results: The velocity and timeaveraged wall shear stress decreased more noticeably with multi-layer stent interventions. A higher oscillatory shear index and relative residence time occurred at the aneurysmal sac wall after multi-layer stents were employed. Time-averaged wall shear stress on the aneurysmal wall decreased with an increase in the number of struts or a decrease in pore size, but oscillatory shear index and relative residence time increased as the number of struts increased or the pore size decreased. Besides, all stents affect the branch patency slightly. In the bending test, when the porosity exceeded 60.5%, multi-layer stents were more flexible., Conclusion: The number of struts or pore size of stent dominated the isolation in the management of the aneurysm and affected the flexibility significantly when the porosity was below 60.5%. These findings may contribute to the special design of the stent in the treatment of such types of aneurysms.

Objective: Biodegradable stents represent a new technological development in the field of cardiovascular angioplasty. The stent geometry plays a crucial role in determining stent performance., Methods: This study describes four stent models with various strut geometries (circular, triangular, hexagonal, and spline) and identical links. The performance of the various stents is assessed by modeling the processes of compression and balloon expansion using experimental and numerical techniques., Results: Four adjustable variables related to radial strength, foreshortening rate, maximum expanded diameter and coverage are considered in this studies. The maximum stress distributions from our numerical analysis are in agreement with the experimental fracture measurements., Conclusion: Analysis of the stent parameters indicates that the hexagonal geometry is a relatively good stent strut design. The results described in this paper will be useful in further optimization studies and for the development of stents with a higher radial strength and increased fracture resistance.

Objectives: Postoperative pancreatic fistula (POPF) is a major concern after pancreatoduodenectomy (PD). We recently designed a new anastomotic method to reduce the rate of pancreatic fistula: polytetrafluoroethylene suture buttress-reinforced pancreaticojejunostomy (PBRP)., Methods: An animal model and a computer simulation were used to measure the maximum stress and tensile strength of the pancreas with and without the suture buttresses. Then, a randomized controlled trial (RCT) was performed to compare the outcome of PD between patients who underwent PBRP vs traditional pancreaticojejunostomy (TP)., Results: The maximum load in the animal model was significantly higher with the suture buttresses than without (5.47 ± 1.67 N vs 3.72 ± 1.36 N, p < 0.01), and in the computer simulation, the peak stress was lower with the suture buttresses than without (54.86 vs 486.8 MPa). There were no significant differences between the two groups in the overall frequency of POPF, but the rate of clinically relevant POPF was significantly lower in the PBRP group (2.8 vs 22.8%, p = 0.028). The pancreaticojejunostomy time was significantly longer in the PBRP group (19.57 ± 3.31 vs 17.17 ± 4.83 min, p = 0.018), and the PBRP group showed a shorter drainage tube retention duration (10 vs 12 days, p = 0.006) and postoperative hospital stay (13 d vs 15 d, p = 0.031)., Conclusions: PBRP is a feasible and reliable procedure for preventing clinically relevant POPF. Additional multi-institution randomized trials should be conducted to confirm these results.

Although multilayer stents (MSs) can be used to treat aneurysm effectively, for some aneurysms with branches attached, the hemodynamic mechanisms are still unclear. In this work, we modeled five cases that involve 1-4-layer stents implanted in aneurysms with side branches, and the numerical approach was used. Case 1 corresponds to an aneurysm without a stent, and cases 2-5 represent 1-4-layer stents being employed within aneurysms, respectively. The results showed that the velocity within the sac declined dramatically and the eddies' intensity weakened with increased number of stent layers, time-averaged wall shear stress (TAWSS), and nitric oxide production rate (TAR NO ) dropped linearly with increase in stent porosity, and oscillatory shear index (OSI) and relative residence time (RRT) increased evidently with MS intervention. Moreover, the MSs had a slight effect on the patency of the side branch; its flow rate was still above the normal case than without aneurysm. It can be concluded that MSs are helpful in promoting the growth of thrombus within the aneurysm through an isolated hemodynamic environment and keeping the branch unobstructed, but more clinical evidences are required.

Background: Blood flow condition may have influence upon the hydraulic conductivity of venous graft (L p,vein ) in an arterial bypass, then affecting the accumulation of low-density lipoproteins (LDLs) within the graft wall. To probe this possibility, we first measured in vitro the filtration rates of swine lateral saphenous vein segments under different flow rates, and the correlation of L p,vein with wall shear stress (WSS) was then obtained., Results: The experimental results showed that when WSS was very low, L p,vein would increase drastically with WSS from 1.16 ± 0.15 × 10 -11 m/s Pa at 0 dyn/cm 2 to 2.17 ± 0.20 × 10 -11 m/s Pa at 0.7 dyn/cm 2 , then became constant of approximately 2.33 × 10 -11 m/s Pa as the WSS increased further. Based on the experimental results, we assumed three different cases of L p,vein and numerically simulated the LDLs transport in an arterial bypass model with venous graft. Case A: L p,vein  = 2.33 × 10 -11 m/s Pa; Case B: L p,vein  = 1.16 × 10 -11 m/s Pa (static condition with WSS of 0); Case C: L p,vein was shear dependent. The simulation showed that the deposition/accumulation of LDLs within the venous graft wall in Case A was greatly enhanced when compared with that in Case B. However, the LDL accumulation in the graft wall was similar for Case A and Case C., Conclusions: Our study, therefore, indicates that when the venous graft was implanted as a bypass graft, the L p,vein might remain nearly constant along its whole length except for very few areas where the value of WSS was extremely low (less than 0.7 dyn/cm 2 ) and the effects of L p,vein modulated by blood flow on LDL transport may be neglected.

Background: The accuracy and safety of pedicle screw insertion was markedly improved with the introduction of intraoperative three-dimensional navigation system during the last decade. This study aimed to evaluate the accuracy of pedicle screw placement using O-arm-based navigation system versus conventional freehand technique., Methods: We reviewed the accuracy of 341 thoracic ( n  = 173) and lumbosacral ( n  = 168) pedicle screws placed in 60 consecutive patients using either O-arm-based navigation or freehand technique in the Department of Neurosurgery of Beijing Tsinghua Changgung Hospital between January 2015 and June 2018. Patient-specific characteristics, treatment-related characteristics, and screw-specific accuracy were analyzed. The accuracy of pedicle screw placement was measured by Gertzbein-Robbins scale and screw grades A and B were clinically acceptable., Results: One hundred ninety-one screws were inserted in the O-arm-based navigation group and 150 in the freehand group. One hundred eighty-three (95.81%) clinically acceptable screws were placed in the navigation group and 135 (90.00%) in the freehand group ( p  = 0.034). Twenty-three (6.74%) screw revisions were performed in the two groups (8 screws in the navigation group and 15 screws in the freehand group) and significant difference was observed in thoracic spine ( p  = 0.018), while no statistical significance was presented in lumbosacral spine ( p  > 0.05). Twenty-four (12.57%) screws in the navigation group and 24 (16.00%) in the freehand group violated the cortex ( p  > 0.05). Medial screw deviation was the most common problem in the two groups., Conclusion: The O-arm-based navigation exhibits higher accuracy for pedicle screw insertion than the freehand insertion technique., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s) 2019.)

Muscle atrophy of the residual limb after lower-limb amputation is a disadvantage of amputees' rehabilitation. To investigate the biomechanics mechanism of muscle atrophy of the residual limb, we built a finite element model of a residual limb including muscle, skeletons and main vessels based on magnetic resonance images of a trans-femoral amputee, and studied the biomechanics effects of the socket of the lower-limb prosthesis on the soft tissue and vessels in the residual limb. It was found that the descending branch of the lateral femoral circumflex artery suffered the most serious constriction due to the extrusion, while that of the deep femoral artery was comparatively light. Besides, the degree of the constriction of the descending branch of the lateral femoral circumflex vein, femoral vein and deep femoral vein decreased in turn, and that of the great saphenous vein was serious. The stress-strain in the anterior femoral muscle group were highest, while the stress concentration of the inferior muscle group was observed at the end of the thighbone, and other biomechanical indicators at the inferior region were also high. This study validated that the extrusion of the socket on the vessels could cause muscle atrophy to some degree, and provided theoretical references for learning the mechanism of muscle atrophy in residual limb and its effective preventive measures.

The phenomenon of sex differences exists in patients who have abdominal aortic aneurysms (AAA). The occurrence rate of AAA is higher in male, while the rates of rupture and postoperative mortality are higher for female. This phenomenon of sex differences would affect the diagnosis, treatment and postoperative rehabilitation for AAA patients. This article reviewed the recent research status of sex differences on AAA, and explored the phenomenon of sex differences from the aspects of threshold determination, biomechanics and mechanobiology. This review points out that the sex differences on AAA could ascribe to the differences of biomechanical environment and biological properties induced by the vascular size, anatomy structure and structure components of abdominal aortic artery. The comprehensive investigations of the sex differences on AAA could help to optimize the diagnosis, treatment and device design, patient care and rehabilitation strategy of AAA based on sex differences phenomenon.

The typical helical flow within the human arterial system is widely used when designing cardiovascular devices, as this helical flow can be generated using the "crossed limbs" strategy of the bifurcated stent graft (BSG) and enhanced by the tapered structure of arteries. Here, we propose the use of a deflected blended bifurcated stent graft (BBSG) with various tapers, using conventional blended BSGs with the same degree of taper as a comparison. Hemodynamic performances, including helical strength and wall shear stress- (WSS-) based indicators, were assessed. Displacement forces that may induce stent-graft migration were assessed using numerical simulations and in vitro experiments. The results showed that as the taper increased, the displacement force, helicity strength, and time-averaged wall shear stress (TAWSS) within the iliac grafts increased, whereas the oscillating shear index (OSI) and relative residence time (RRT) gradually decreased for both types of BBSGs. With identical tapers, deflected BBSGs, compared to conventional BBSGs, exhibited a wider helical structure and lower RRT on the iliac graft and lower displacement force; however, there were no differences in hemodynamic indicators. In summary, the presence of tapering facilitated helical flow and produced better hemodynamic performance but posed a higher risk of graft migration. Conventional and deflected BBSGs with taper might be the two optimal configurations for endovascular aneurysm repair, given the helical flow. The deflected BBSG provides a better configuration, compared to the conventional BBSG, when considering the reduction of migration risk.

Background: Abdominal aortic aneurysm (AAA) is a kind of dangerous aortic vascular disease, which is characterized by abdominal aorta partial enlargement. At present, endovascular aneurysm repair (EVAR) is one of the main treatments of abdominal aortic aneurysm. However for some patients after EVAR the aneurysm re-expanded and even ruptured, leading to poor postoperative effect. The stent-graft endoleak after EVAR was realized to influence the AAA in-sac pressure and contribute to the aneurysm re-enlargement., Methods: In order to analyze the influence of endoleaks positions on the pressure shielding ability of stent-graft after EVAR, type I and type III endoleak models were reconstructed based on computed tomography (CT) scan images, and the hemodynamic environment in AAA was numerically simulated., Results: When the endoleak was at the proximal position the pressure shielding ability will be obviously weakened. While, the pressure shielding ability was higher in the systole phase than that in diastole phase when the endoleak located at the middle or distal positions. Unfortunately, when the endoleak located at the proximal position, the pressure shielding ability would be relatively weak in the whole cardiac cycle., Conclusions: The results revealed that the influence of endoleaks on pressure shielding ability of stent-graft was both location and time specific.

Helical flow has been introduced to improve the hemodynamic performance of vascular devices such as arterial grafts, stents and arteriovenous shunts to overcome the flow induced thrombus formation and intimal hyperplasia. However, the quite low intensity of helical flow in the existing devices may limit their function. To obtain desirably high intensity, inspired by the helical flow and tapered configuration of the arterial system, we proposed a new conceptual design of the medical devices, which take the form of a tapered helical shape. We demonstrated its effectiveness in arterial grafts by numerically comparing the hemodynamic performance of helical grafts with different smooth tapers. The results show that the helicity density quantifying the helical flow enlarges sharply with the increase of the taper under both steady and pulsatile flow conditions. Moreover, the amplified helical flow induced by the taper would lead to highly elevated wall shear stress, remarkably reduced oscillating shear index and relative residence time at both the grafts and the anastomosis of the host vessel. The present findings therefore indicated that the new helical graft with taper would significantly enhance the helical flow in the grafts and host vessel, which may reduce the possibility of thrombus formation in the graft and intimal hyperplasia in the host vessel and hence improve the graft patency. In addition, the concept of helical shape with taper may also be applied to design arterial stents and arteriovenous shunts to obtain better hemodynamic performance., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The glycocalyx is a key mechanosensor on the surfaces of vascular cells (endothelial cells and smooth muscle cells), and recently, we reported that the redistribution of the hemodynamic factors in tail-suspended (TS) hindlimb-unloaded rats induces the dimensional adaptation of the endothelial glycocalyx in a regional-dependent manner. In the present study, we investigated the coverage and gene expression of the glycocalyx and its possible relationship with smooth muscle contractility in the conduit arteries from the TS rats. The coverage of the glycocalyx, determined by the area analysis of the fluorescein isothiocyanate-labeled wheat germ agglutinin (WGA-FITC) staining to the cryosections of rat vessels, showed a 27.2% increase in the common carotid artery, a 13.3 and 8.0% decrease in the corresponding abdominal aorta and the femoral artery after 3 wk of tail suspension. The relative mRNA levels of syndecan-2, 3, 4, glypican-1, smooth muscle protein 22 (SM22), smoothelin (SMTN), and calponin were enhanced to 1.40, 1.53, 1.70, 1.90, 2.93, 2.30, and 5.23-fold, respectively, in the common carotid artery of the TS rat. However, both glycocalyx-related genes and smooth muscle contractile apparatus were totally or partially downregulated in the abdominal aorta and femoral artery of the TS rat. A linear positive correlation between the normalized coverage of glycocalyx and normalized mRNA levels of SM22, SMTN, and calponin exists. These results suggest the regional-dependent adaptation of the glycocalyx in simulated microgravity condition, which may affect its mechanotransduction of shear stress to regulate the contractility of the smooth muscle, finally contributing to postspaceflight orthostatic intolerance., (Copyright © 2016 the American Physiological Society.)

The aim of this study was to investigate the drug distribution in arteries treated with DES-BMS stenting strategy and to analyze the influence of proximal DES on distal segments of BMS. A straight artery model (Straight Model) and a branching artery model (Branching Model) were constructed in this study. In each model, the DES was implanted at the proximal position and the BMS was implanted distally. Hemodynamic environments, drug delivery and distribution features were simulated and analyzed in each model. The results showed that blood flow would contribute to non-uniform drug distribution in arteries. In the Straight Model the proximal DES would cause drug concentration in BMS segments. While in the Branching Model the DES in the main artery has slight influence on the BMS segments in the branch artery. In conclusion, due to the blood flow washing effect the uniformly released drug from DES would distribute focally and distally. The proximal DES would have greater influence on the distal BMS in straight artery than that in branching artery. This preliminary study would provide good reference for atherosclerosis treatment, especially for some complex cases, like coronary branching stenting., (Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.)

Previous animal studies by using tail-suspended hindlimb-unloaded rat model have shown that simulated microgravity-induced vessel structural and functional remodeling may be anatomic region dependent. However, little care has been taken to assess the structural adaptation of the endothelial glycocalyx, the apical surface of the endothelium, the key mechanosensor mediating nitric oxide (NO) production, and the natural protective barrier of the vasculature. Therefore, the present study extended simulated microgravity-induced vessel remodeling to the endothelial glycocalyx level. The percents of bone mineral density (BMD) change from both control and tail-suspended (TS) rats were measured by micro-computed tomography (Micro-CT). Structural parameters such as the luminal diameter (D), the thickness of each layer, the ratio of intima to media (IMR), the cross-sectional areas of the intima (CSAI) and media (CSAM) of vessels from three different regions (the common carotid artery, abdominal aorta, and femoral artery) were assessed by hematoxylin and eosin staining. Dimensions of the glycocalyx above, below, and away from the endothelial cell nucleus were examined by fluorescein isothiocyanate-labeled wheat germ agglutinin (WGA-FITC) binding to the cryosection of vessels. Our results show that 3-week tail suspension of rats increases the thickness and CSA of the abdominal aortic endothelium by 23.7 and 21.1%, respectively, thickens the media layer of the common carotid artery by 34.0%, and increases the luminal diameter, the CSA of the intima and media of the femoral artery by 75.7, 93, and 61.2%, respectively. Correspondingly, the dimension of the glycocalyx away from the common carotid arterial and the abdominal aortic endothelial cell nucleus from tail-suspended rats shows a 1.66- and 1.64-fold increase respectively, while it shows a 0.79-fold reduction on the top of the femoral endothelial cells. These results suggest that simulated microgravity induces vascular endothelial glycocalyx remodeling in a regional-dependent manner. The perturbation of the endothelial glycocalyx at the lower body artery may be the first event of vascular remodeling initiating endothelial dysfunction, contributing to postspaceflight orthostatic intolerance.

Despite the crucial role of nitric oxide (NO) in the homeostasis of the vasculature, little quantitative information exists concerning NO transport and distribution in medium and large-sized arteries where atherosclerosis and aneurysm occur and hemodynamics is complex. We hypothesized that local hemodynamics in arteries may govern NO transport and affect the distribution of NO in the arteries, hence playing an important role in the localization of vascular diseases. To substantiate this hypothesis, we presented a lumen/wall model of the human aorta based on its MRI images to simulate the production, transport and consumption of NO in the arterial lumen and within the aortic wall. The results demonstrated that the distribution of NO in the aorta was quite uneven with remarkably reduced NO bioavailability in regions of disturbed flow, and local hemodynamics could affect NO distribution mainly via flow dependent NO production rate of endothelium. In addition, erythrocytes in the blood could moderately modulate NO concentration in the aorta, especially at the endothelial surface. However, the reaction of NO within the wall could only slightly affect NO concentration on the luminal surface, but strongly reduce NO concentration within the aortic wall. A strong positive correlation was revealed between wall shear stress and NO concentration, which was affected by local hemodynamics and NO reaction rate. In conclusion, the distribution of NO in the aorta may be determined by local hemodynamics and modulated differently by NO scavengers in the lumen and within the wall.

Objective: To test the hypothesis that the venous graft when implanted in an arterial bypass might endure a significantly elevated water filtration rate, leading to fast infiltration/accumulation of low-density lipoproteins (LDLs) within the graft wall and hence the accelerated atherogenesis., Methods: We measured filtration rates of the swine femoral artery and lateral saphenous vein under venous and arterial hemodynamic conditions in vitro. Based on the measured filtration rates, we numerically simulated LDL transport in an arterial bypass model with a venous graft. Moreover, in order to validate the theoretical prediction, we measured DiI-LDLs uptake by both arteries and veins under arterial condition., Results: The experimental results showed that when subjected to arterial hemodynamic condition, the filtration rate of the venous wall was increased sharply, and significantly higher than that of the artery. Moreover, different from the hydraulic conductivity of artery, the venous one would increase with increasing pressure. The numerical results showed that for the venous graft, both luminal surface LDL concentration and LDL accumulation within the vessel wall were significantly higher than those for the host artery. In addition, the experiment, which was used to confirm theoretical prediction, showed that the amount of DiI-LDLs uptake by the venous wall was much higher compared with arterial wall., Conclusion: The present study suggests that the accelerated atherogenesis of the venous graft is attributable to its elevated filtration rate that may lead to both aggravated concentration polarization of LDLs and enhanced convective transport of LDLs into the graft wall., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

To elucidate the difference between Newtonian and shear thinning non-Newtonian assumptions of blood in the analysis of DES drug delivery, we numerically simulated the local flow pattern and the concentration distribution of the drug at the lumen-tissue interface for a structurally simplified DES deployed in a curved segment of an artery under pulsatile blood flow conditions. The numerical results showed that when compared with the Newtonian model, the Carreau (shear thinning) model could lead to some differences in the luminal surface drug concentration in certain areas along the outer wall of the curved vessel. In most areas of the vessel, however, there were no significant differences between the 2 models. Particularly, no significant difference between the two models was found in terms of the area-averaged luminal surface drug concentration. Therefore, we believe that the shear thinning property of blood may play little roles in DES drug delivery. Nevertheless, before we draw the conclusion that Newtonian assumption of blood can be used to replace its non-Newtonian one for the numerical simulation of drug transport in the DES implanted coronary artery, other more complex mechanical properties of blood such as its thixotropic behavior should be tested.