Exceptional figure of merit achieved in boron-dispersed GeTe-based thermoelectric composites.

GeTe is a promising p-type material with increasingly enhanced thermoelectric properties reported in recent years, demonstrating its superiority for mid-temperature applications. In this work, the thermoelectric performance of GeTe is improved by a facile composite approach. We find that incorporating a small amount of boron particles into the Bi-doped GeTe leads to significant enhancement in power factor and simultaneous reduction in thermal conductivity, through which the synergistic modulation of electrical and thermal transport properties is realized. The thermal mismatch between the boron particles and the matrix induces high-density dislocations that effectively scatter the mid-frequency phonons, accounting for a minimum lattice thermal conductivity of 0.43 Wm-1K-1 at 613 K. Furthermore, the presence of boron/GeTe interfaces modifies the interfacial potential barriers, resulting in increased Seebeck coefficient and hence enhanced power factor (25.4 µWcm-1K-2 at 300 K). Consequently, we obtain a maximum figure of merit Zmax of 4.0 × 10-3 K-1 at 613 K in the GeTe-based composites, which is the record-high value in GeTe-based thermoelectric materials and also superior to most of thermoelectric systems for mid-temperature applications. This work provides an effective way to further enhance the performance of GeTe-based thermoelectrics.

Direct oral anticoagulants in the treatment of chronic thromboembolic pulmonary hypertension patients: A retrospective cohort study.

INTRODUCTION: Direct oral anticoagulants (DOACs) are increasingly prescribed for life-long anticoagulation in chronic thromboembolic pulmonary hypertension (CTEPH) patients, despite not being recommended in the guidelines. This study aims to evaluate the efficacy and safety of DOACs in CTEPH patients. METHODS: From May 2013 to December 2022, patients who were first diagnosed with CTEPH in Fuwai Hospital and started long-term anticoagulation treatment with warfarin or DOACs were retrospectively included and followed up until (1) death, (2) transition to other kinds of anticoagulants, or (3) discontinuation of anticoagulation. Propensity score matching was used to balance confounding bias of baseline characteristics. All-cause death, major bleeding, clinically relevant nonmajor bleeding and venous thromboembolism (VTE) recurrence were obtained and analysed. RESULTS: After propensity score matching, 115 patients taking warfarin and 206 patients taking DOACs were included in our study and followed up for 5.5 [3.4, 7.1] years. There was no significant difference of survival between the warfarin and the DOAC group (p = 0.77). The exposure adjusted event rate of major bleeding (0.3 %/person-year vs 0.4 %/person-year, p = 0.705) and clinically relevant nonmajor bleeding (3.1 %/person-year vs 3.2 %/person-year, p > 0.999) was similar between two groups. The exposure adjusted rate of VTE recurrence was significantly higher in the DOAC group (1.5 %/person-year vs 0.3 %/person-year, p = 0.030). CONCLUSION: In anticoagulation of CTEPH patients, DOACs have similar survival rate, similar risk of bleeding but higher risk of VTE recurrence than warfarin.

Numerical design and characterization of a novel parallel beam combined lens based on X-ray capillary optics.

A novel parallel beam combined lens (PBCL) was designed based on a parabolic monocapillary x-ray lens (PMXRL). The proposed PBCL converted a divergent X-ray beam into a near-solid parallel one, which retains the low divergence characteristics of PMXRL and significantly improves the intensity gain by about one order of magnitude. Compared with the traditional polycapillary parallel x-ray lens (PPXRL), the divergence performance of this lens is improved by an order of magnitude, and the light intensity gain is improved by 3-4 times. In addition, we developed a MATLAB-based visualization tool to simulate X-ray transmission within the PBCL through ray tracing. This tool facilitated the assessment of the PBCL's transmission efficiency and its comparison with conventional PMXRL and the PPXRL. The transport process of the PBCL is systematically investigated under the comprehensive consideration of multiple parameters. This study provided a new idea and theoretical basis for the further development of X-ray modulation technology.

The safety and feasibility assessment of overlap esophagojejunostomy with self-pulling and latter transection technique in totally laparoscopic total gastrectomy.

BACKGROUND: This study presented an innovative technique in totally laparoscopic total gastrectomy (TLTG) for overlap esophagojejunostomy (E-J), termed self-pulling and latter transection (SPLT) (overlap SPLT). It evaluated the effectiveness and short-term outcomes of this novel method through a comparative analysis with the established functional end-to-end (FETE) E-J incorporating SPLT. METHODS: From September 2018 to September 2023, this study enrolled 68 patients with gastric cancer who underwent TLTG with overlap SPLT anastomosis and 120 patients who underwent TLTG with FETE SPLT anastomosis. Clinicopathologic characteristics and surgical and postoperative outcomes data for overlap SPLT cases were gathered and retrospectively compared with those from FETE SPLT TLTG to evaluate the effectiveness and clinical safety. RESULTS: The duration of anastomosis for overlap SPLT was 25.3 ± 7.4 minutes, significantly longer than that for the FETE SPLT (18.1 ± 4.0 minutes, P = .031). Perioperatively, 1 anastomosis-related complication occurred in each group, but this did not constitute a statistically significant difference (P = .682). No statistically significant differences were found between the 2 groups in terms of operative time, postoperative hospital stay, operative cost, surgical margins, or number of lymph nodes removed. Postoperative morbidity rates were similar between the groups (4.4% vs 5.8%, P = .676). CONCLUSION: The overlap SPLT technique is regarded as a safe and feasible method for anastomosis. There were no apparent differences in complications between overlap SPLT and FETE SPLT, but overlap SPLT costed 1 additional stapler cartridge and required a longer duration.

Understanding adherence to continuous positive airway pressure in patients with obstructive sleep apnea post-stroke: A prospective study based on the Andersen model.

Adherence to continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA) post-stroke is often problematic, despite potential benefits. This study aimed to evaluate CPAP adherence in patients with OSA post-stroke based on the Andersen behavioral model of health services utilization. A total of 227 eligible participants were recruited from a Chinese hospital. After baseline assessment, participants were followed for 6 months to determine short-term CPAP adherence. Those with good short-term adherence were followed for an additional 6 months to explore long-term adherence and influencing factors. Short-term CPAP adherence rate was 33%. Being married or living with a partner, having an associate degree or baccalaureate degree or higher, and stronger health beliefs independently predicted short-term CPAP adherence. Only 25% of participants from the adherent group showed good long-term adherence. The factor associated with long-term CPAP adherence was participants not using alcohol. Adherence to CPAP is suboptimal among patients having OSA post-stroke. Addressing unfavorable predisposing factors and modifying health beliefs are suggested.

A hemodynamic model of artery bypass graft considering microcirculation function.

BACKGROUND: The incidence of arterial stenosis is increasing year by year. In order to better diagnose and treat arterial stenosis, numerical simulation technology has become a popular method. OBJECTIVE: A novel model is constructed to investigate the influence of microcirculation on the hemodynamics of artery bypass graft. METHODS: In this paper, a severely narrow artery bypass graft model is considered. The geometric shape includes a narrow artery tube and a bypass graft of the same diameter with a 45° suture angle. The fluid-structure interaction model is considered by finite element numerical calculation, and the flow is simulated with microcirculation as the outlet boundary condition. The changes of blood flow velocity, pressure and wall shear stress are analyzed. RESULTS: The results show that blood almost entirely flows into the graft tube and there is no recirculation area at the anastomosis. CONCLUSION: The artery bypass graft model considering microcirculation function could simulate the physiological characteristics of blood flow more reasonably, and it provide helps for clinicians to diagnose and treat arterial stenosis.

Highly stabilized and efficient thermoelectric copper selenide.

The liquid-like feature of thermoelectric superionic conductors is a double-edged sword: the long-range migration of ions hinders the phonon transport, but their directional segregation greatly impairs the service stability. We report the synergetic enhancement in figure of merit (ZT) and stability in Cu1.99Se-based superionic conductors enabled by ion confinement effects. Guided by density functional theory and nudged elastic band simulations, we elevated the activation energy to restrict ion migrations through a cation-anion co-doping strategy. We reduced the carrier concentration without sacrificing the low thermal conductivity, obtaining a ZT of ∼3.0 at 1,050 K. Notably, the fabricated device module maintained a high conversion efficiency of up to ∼13.4% for a temperature difference of 518 K without obvious degradation after 120 cycles. Our work could be generalized to develop electrically and thermally robust functional materials with ionic migration characteristics.

Numerical investigation of quantitative pulmonary pressure ratio in different degrees of stenosis.

BACKGROUND: Pulmonary artery stenosis endangers people's health. Quantitative pulmonary pressure ratio (QPPR) is very important for clinicians to quickly diagnose diseases and develop treatment plans. OBJECTIVE: Our purpose of this paper is to investigate the effects of different degrees (50% and 80%) of pulmonary artery stenosis on QPPR. METHODS: An idealized model is established based on the normal size of human pulmonary artery. The hemodynamic governing equations are solved using fluid-structure interaction. RESULTS: The results show that the QPPR decreases with the increase of stenosis degree, and it is closely related to the pressure drop at both ends of stenosis. Blood flow velocity and wall shear stress are sensitive to the stenosis degree. When the degree of stenosis is 80%, the amplitude of changes of blood flow velocity and wall shear stress at both ends of stenosis is lower. CONCLUSIONS: The results suggest that the degree of pulmonary artery stenosis has a significant impact on QPPR and hemodynamic changes. This study lays a theoretical foundation for further study of QPPR.

Development of an UPLC-MS/MS method for quantitative analysis of abexinostat levels in rat plasma and application of pharmacokinetics.

Broad-spectrum histone deacetylase inhibitors (HDACi) have excellent anti-tumor effects, such as abexinostat, which was a novel oral HDACi that was widely used in clinical treatment. The purpose of this study was to establish a rapid and reliable method for the detection of abexinostat concentrations in rat plasma using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The mobile phase we used was acetonitrile and 0.1% formic acid, and the internal standard (IS) was givinostat. Selective reaction monitoring (SRM) was used for detection with ion transitions at m/z 397.93 → 200.19 for abexinostat and m/z 422.01 → 186.11 for givinostat, respectively. The intra-day and inter-day precision of abexinostat were less than 11.5% and the intra-day and inter-day accuracy ranged from - 10.7% to 9.7% using this method. During the analysis process, the stability of the test sample was reliable. In addition, the recovery and matrix effects of this method were within acceptable limits. Finally, the method presented in this paper enabled accurate and quick determination of abexinostat levels in rat plasma from the pharmacokinetic study following gavage at a dose of 8.0 mg/kg abexinostat.

Magnified x ray ghost imaging with tapered polycapillary optics free of the penumbra effect.

X ray ghost imaging (XGI) offers both radiation dose-reduction potential and cost-effective benefits owing to the utilization of a single-pixel detector. Most XGI schemes with laboratory x ray sources require a mechanically moving mask for either structured illumination or structured detection. In either configuration, however, its resolution remains limited by the source size and the unit size of the mask. Upon propagation, the details of the object can actually be magnified by the divergence of x rays, but at the same time, the penumbra effect produced by the finite source size is dramatically intensified, which ultimately leads to a degradation of image quality in XGI. To address these limitations, this work proposes a magnified XGI scheme using structured detection equipped with tapered polycapillary optics, which can efficiently suppress the object's penumbra as well as resolve the magnified details of the object. In general, the resolution of this scheme is no longer affected by the source size but by the microcapillary size of polycapillary. Our work fundamentally achieves cancellation of penumbra effect-induced aberration, thus paving the way for high-resolution magnified XGI.

Prognostic significance of quantitative electrocardiographic parameters in patients with non-high-risk pulmonary embolism.

BACKGROUND: Electrocardiogram (ECG) abnormalities indicating right ventricular strain have been reported to have prognostic value in severe cases of acute pulmonary embolism (PE). We aimed to analyze the prognostic significance of other quantitative ECG parameters in non-high-risk acute PE. METHODS: Consecutive patients with non-high-risk acute PE were prospectively enrolled. The following baseline ECG parameters were collected: rhythm, heart rate, QRS axis, right bundle branch block (RBBB) pattern, S1Q3T3 pattern, T-wave inversion, ST-segment elevation, Qr in lead V1, PR Interval, QRS complex duration, QT interval, P-wave amplitude and duration, R- and S-wave amplitudes. The primary endpoint was early discharge within three days. Associations between ECG parameters and early discharge were analyzed. RESULTS: Overall, 383 patients were enrolled (median age: 67 years, 57% female): 277 (72.3%) with low-risk and 106 (27.7%) with intermediate-risk. The two groups of patients differed in several ECG signs of right ventricular strain and many other quantitative parameters like R- and S-wave amplitudes. In the multivariate logistic regression analysis, the S-wave depth in lead V5 (S-V5) was the only independent prognostic factor for early discharge (odds ratio = 0.137, 95% confidence interval = 0.031-0.613, p = 0.009). The optimum cutoff value of S-V5 for predicting early discharge derived from the receiver operative characteristic curve was 0.15 mv (c-statistic = 0.66, p =0.003). CONCLUSIONS: Several ECG signs of right ventricular strain and many other quantitative parameters were associated with disease severity in non-high-risk acute PE. An S-V5 lesser than 0.15 mv was predictive for early discharge in these patients.

Protective effect and mechanism of quercetin on cardiac and renal functions in rats with cardiorenal syndrome / 中国药房

OBJECTIVE To investigate the protective effect and mechanism of quercetin on the cardiac and renal functions of rats with cardiorenal syndrome （CRS） based on the phosphoinositide 3-kinase （PI3K）/protein kinase B （Akt）/nuclear factor kappa- B （NF-κB） signaling pathway. METHODS CRS model of SD rats was induced by left anterior descending coronary artery ligation combined with acute renal ischemia-reperfusion. Model rats were randomly separated into model group， quercetin low-dose group （35 mg/kg）， quercetin high-dose group （70 mg/kg）， high-dose of quercetin+740Y-P group （70 mg/kg quercetin+3.5 mg/kg PI3K/Akt/ NF-κB signaling pathway activator 740Y-P）， with 12 rats in each group. Another 12 normal rats were selected as sham operation group. They were given relevant drugs， once a day， for 14 consecutive days. After administration， the cardiac function indexes [left ventricular ejection fraction （LVEF）， end-diastolic volume （EDV）， isovolumic relaxation time （IVRT）] and renal function indicators [blood urea nitrogen （BUN）， 24-hour urine protein， and serum creatinine （Scr）] were detected， and fibrosis in the cardiac and renal tissues was observed； the levels of inflammatory indexes [interleukin-1β （IL-1β） and tumor necrosis factor-α （TNF-α）] in the serum and cardiac and renal tissues as well as the expression of PI3K/Akt/NF-κB pathway-related proteins in the cardiac and renal tissues were detected. RESULTS Compared with sham operation group， the levels of BUN， 24-hour urine protein and Scr， collagen volume fraction of cardiac and renal tissues， the levels of IL-1β and TNF-α in serum and cardiac and renal tissues， and the phosphorylation of PI3K， Akt and NF-κB p65 protein in cardiac and renal tissues were increased significantly in model group （P＜0.05）； the levels of LVEF， IVRT and EDV were reduced significantly （P＜0.05）. Compared with the model group， the above indexes were reversed significantly in quercetin low-dose and high-dose groups （P＜0.05）， and the reversal effect was better in the high-dose group （P＜0.05）. 740Y-P restored the reverse effect of high-dose quercetin on the indexes （P＜0.05）. CONCLUSIONS Quercetin can alleviate cardiac and renal fibrosis and function injury， the mechanism of which may be 20232016） associated with inhibiting the activation of the PI3K/Akt/NF-κB signaling pathway.

Clinical Observation on the FANG's Scalp Acupuncture Combined with Timing Auricular Point Pressing Therapy in the Treatment of Insomnia Patients with Maintenance Hemodialysis / 广州中医药大学学报

Objective To observe the clinical efficacy of FANG's scalp acupuncture combined with timing auricular point pressing therapy in the treatment of insomnia patients with maintenance hemodialysis(MHD).Methods A total of 70 patients with insomnia on MHD were randomly divided into observation group and control group,with 35 patients in each group.Both groups were given conventional treatment,the control group was given oral use of Estazolam Tablets on the basis of conventional treatment,and the observation group was given FANG's scalp acupuncture combined with timing auricular point pressing therapy.Both groups were treated for a total of 4 weeks of treatment.After 1 month of treatment,the clinical efficacy of the two groups was evaluated,and the changes in the Pittsburgh Sleep Quality Index(PSQI)score and the Kidney Disease Quality of Life Short Form(KDQOL-SF)score,as well as the scores of the Hamilton Depression Scale(HAMD)and the Hamilton Anxiety Scale(HAMA),were observed in the patients of the two groups before and after treatment.The changes in hemoglobin(Hb),serum creatinine(Scr),and blood urea nitrogen(BUN)levels were compared before and after treatment between the two groups,and the safety of the two groups was evaluated.Results(1)After treatment,the PSQI and KDQOL-SF scores of patients in the two groups were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving PSQI and KDQOL-SF scores,and the difference was statistically significant(P＜0.05).(2)After treatment,the HAMD and HAMA scores of patients in the two groups were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving HAMD and HAMA scores,and the differences were statistically significant(P＜0.05).(3)After treatment,the Hb,Scr,BUN levels of patients in the two groups were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving Hb,Scr,BUN levels,and the differences were all statistically significant(P＜0.05).(4)The total effective rate was 77.14%(27/35)in the observation group and 62.86%(22/35)in the control group.The efficacy of the observation group was superior to that of the control group,and the difference was statistically significant(P＜0.05).(5)Comparison of the incidence of adverse reactions in the two groups of patients,the difference was not statistically significant(P＞0.05).Conclusion FANG's scalp acupuncture combined with timing auricular point pressing therapy in the treatment of insomnia patients with MHD can effectively improve the sleep quality of patients and alleviate anxiety and depression,so as to improve the quality of life of patients,with remarkable efficacy.

Identification, expression and protein interaction analysis of Aux/IAA and ARF gene family in Senna tora L / 药学学报

The early response of plant auxin gene family Aux/IAA (auxin/indole-3-acetic acid) and its interaction with auxin response factor (ARF) are important pattern to regulate plant growth and development. This work identified 28 StoIAA and 24 StoARF members based on the whole genome data of the medicinal plant Senna tora L., which were classified into 10 and 8 subfamilies, respectively. Phylogenetic tree and collinearity analysis showed that S. tora has close evolutionary relationship with the IAA and ARF homologous genes of Glycine max, Medicago truncatula, and the segment duplication events dominate the expansion of StoIAA and StoARF. Gene structure analysis showed that the vast majority of StoIAA and StoARF contain characteristic conserved domain. Transcriptome data showed that StoIAAs and StoARFs were expressed in leaves, roots and seeds, some members had tissue specific expression. The StoIAA and StoARF promoter region most contain functional elements related to stress response, growth and development, hormone induction and secondary metabolism. In addition, gene expression analysis showed that many StoIAAs and StoARFs can quickly respond to drought and salt stress and exhibited same expression patterns under both stress condition. The yeast two-hybrid experiment confirmed that StoARF8 and StoARF10 exhibit varying degrees of interaction with multiple StoIAA proteins, respectively. The above results provide a basis for further biological functional analysis of the Aux/IAA and ARF gene family of S. tora.

Wide-temperature-range thermoelectric n-type Mg3(Sb,Bi)2 with high average and peak zT values.

Mg3(Sb,Bi)2 is a promising thermoelectric material suited for electronic cooling, but there is still room to optimize its low-temperature performance. This work realizes >200% enhancement in room-temperature zT by incorporating metallic inclusions (Nb or Ta) into the Mg3(Sb,Bi)2-based matrix. The electrical conductivity is boosted in the range of 300-450 K, whereas the corresponding Seebeck coefficients remain unchanged, leading to an exceptionally high room-temperature power factor >30 µW cm-1 K-2; such an unusual effect originates mainly from the modified interfacial barriers. The reduced interfacial barriers are conducive to carrier transport at low and high temperatures. Furthermore, benefiting from the reduced lattice thermal conductivity, a record-high average zT > 1.5 and a maximum zT of 2.04 at 798 K are achieved, resulting in a high thermoelectric conversion efficiency of 15%. This work demonstrates an efficient nanocomposite strategy to enhance the wide-temperature-range thermoelectric performance of n-type Mg3(Sb,Bi)2, broadening their potential for practical applications.

Causal relationships of circulating amino acids with cardiovascular disease: a trans-ancestry Mendelian randomization analysis.

BACKGROUND: Epidemiological studies demonstrated that multiple amino acids (AAs) were associated with cardiovascular diseases (CVDs), but whether these associations were causal remains unclear. This study aims to investigate the causal relationships between circulating levels of 20 AAs and 10 CVDs in European and East Asian populations by Mendelian randomization (MR). METHODS: This MR study utilized single-nucleotide polymorphisms that were significantly associated with AAs as instrumental variables. Summary-level data for AAs and CVDs were obtained from public genome-wide association studies. The causal effects were primarily estimated by inverse variance weighting with multiplicative random effect method. Sensitivity analyses, including weighted median, weighted mode, and MR Egger regression, were used to test the robustness of our results. RESULTS: In the European population, alanine and serine were inversely associated with angina pectoris (AP) and chronic heart failure, respectively. With each unit increase of leucine, the risk of ischemic stroke increased by 10%. Moreover, tyrosine was positively associated with AP and deep vein thrombosis. In the East Asian population, each unit increase in glycine was associated with 4.1% and 9.0% decreased risks of coronary artery disease (CAD) and myocardial infarction (MI), respectively. A unit increase in serine was associated with 13.1%, 12.6% and 15.5% decreased risks of AP, CAD and MI, respectively. Sensitivity analyses supported the robustness of our results. CONCLUSIONS: This MR study demonstrated significant causal effects of circulating levels of AAs on CVDs, indicating the potential use of AAs as biomarkers or as therapeutic targets for CVD in clinical scenarios.

Clinical Efficacy Evaluation of Ultrasound-Guided C2 Dorsal Root Nerve Pulsed Radiofrequency Combined with Stellate Ganglion Block in the Treatment of Cervicogenic Headache: A Retrospective Cohort Study.

Purpose: To explore the therapeutic effect of C2 dorsal root ganglion pulsed radiofrequency (PRF) combined with stellate ganglion block (SGB) in patients with cervicogenic headache (CEH). Patients and Methods: We retrospectively reviewed 90 patients diagnosed with CEH who were admitted to our hospital between May 2019 and May 2022. All patients were divided into three groups (n = 30 each) according to the actual treatment method used: ultrasound-guided SGB, ultrasound-guided C2 dorsal root ganglion PRF treatment, and ultrasound-guided C2 dorsal root ganglion PRF combined with SGB treatment. Patients' pain intensity, sleep, and mood changes were assessed by statistically analyzing their pain visual analog scale (VAS), Pittsburgh Sleep Quality Inventory (PSQI), and short-form McGill Pain Questionnaire affective item scores before and after treatment. Results: The post-treatment VAS, PSQI, and McGill scores were significantly decreased in all patients (P < 0.05), and all three scores in ultrasound-guided C2 dorsal root ganglion PRF combined with SGB were lower than those in ultrasound-guided SGB alone and ultrasound-guided C2 dorsal root ganglion PRF alone (P < 0.05). Conclusion: The use of ultrasound-guided C2 dorsal root ganglion PRF combined with SGB in patients with CHE is effective in alleviating pain and improving sleep, and deserves to be replicated in the clinic.

Untargeted metabolomics reveal the metabolic profile of normal pulmonary circulation.

BACKGROUND: As an important place of material exchange, the homeostasis of the pulmonary circulation environment and function lays an essential foundation for the normal execution of various physiological functions of the body. Small metabolic molecules in the circulation can reflect the corresponding state of the pulmonary circulation. METHODS: We enrolled patients with Patent Foramen Ovale and obtained blood from the pulmonary arteries and veins through heart catheterization. UPLC-MS based untargeted metabolomics was used to compare the changes and metabolic differences of plasma between pulmonary vein and pulmonary artery. RESULTS: The plasma metabolomics revealed that pulmonary artery had a different metabolomic profile compared to venous. 1060 metabolites were identified, and 61 metabolites were differential metabolites. Purine, Amino acids, Nicotinamide, Tetradecanedioic acid and Bile acid were the most markedly. CONCLUSION: The differential metabolites are mostly related to immune inflammation and damage repaired. It is suggested that the pulmonary circulation is always in a steady state of injury and repair while pathological changes may be triggered when the homeostasis is broken. These changes play an important role in revealing the development process and etiology of lung homeostasis and related diseases. Relevant metabolites can be used as potential targets for further study of pulmonary circulation homeostasis.

Numerical simulation of hemodynamics in patient-specific pulmonary artery stenosis.

BACKGROUND: The incidence rate of pulmonary artery stenosis is increasing year by year and its numerical simulation has become a key project of biomedical engineering. OBJECTIVE: The purpose of this work is to study the changes of hemodynamic parameters in patient-specific pulmonary artery stenosis. METHODS: A pulmonary artery stenosis model is established based on patient-specific computed tomography (CT) images. According to the actual anatomy of patient-specific pulmonary artery stenosis, the stenosis area is simulated using a porous medium to study its hemodynamic changes. The computational fluid dynamics (CFD) method is used to simulate the hemodynamic changes of pulmonary artery stenosis, and to explore the mechanical characteristics between blood flow and vessel wall. RESULTS: The results suggest that the blood pressures of arterial branches increase and the pressure drop at both ends of the stenosis is higher. There is a high flow rate and wall shear stress at the stenosis. CONCLUSION: This study shows that the hemodynamic model of pulmonary artery stenosis can be accurately reconstructed by achieving numerical simulation of the local stenosis through CT images, and this work has important implications for improving the confidence of clinical diagnosis and treatment of pulmonary artery diseases.