Flow Index Research Articles

Invasive quantitative assessment of coronary microvascular dysfunction in patients with hypertrophic cardiomyopathy

Abstract Background Patients (P) with hypertrophic cardiomyopathy (HCM) commonly suffer from coronary microvascular dysfunction (CMD) - the affection of function/structure of the coronary microvasculature. Invasive assessment of CMD through thermodilution methods allows for the calculation of coronary flow reserve (CFR) and index of microvascular resistance (IMR). These methods, while extensively studied in the context of non-obstructive coronary artery disease and myocardial infarction, have not been thoroughly validated in HCM P. Objectives To invasively assess the presence of CMD in P with HCM and to determine clinical predictors of invasively assessed CMD. Methods In a prospective single-centre study, we opportunistically recruited consecutive adult P with an established diagnosis of HCM with or without LVOTO that had an indication to pursue elective coronarography – such as pre-procedural evaluation for alcoholic septal ablation (ASA) or exclusion of epicardial coronary artery disease. P characteristics and coronary hemodynamic invasive assessment data were extracted. CFR was calculated as the ratio between resting and hyperemia mean transit times (TmnRest;TmnHyper). IMR was calculated as the ratio between distal coronary pressure (Pd) and the inverse of TmnHyper (IMR=Pd/TmnHyper-1). A cutoff of ≤22.0 in IMR, an ≥d 2 in CFR was used. We excluded P with end-stage HCM (LV EF <50% and/or or left ventricular wall thinning), or with epicardial coronary artery disease. Continuous variables were reported as mean ± SD or median and IQR depending on data distribution pattern and categorical data as frequencies and percentages. A linear regression model was used to test predictors of IMR and CFR involvement. Results 25 HCM P with a mean age of 63±10 years were included, 14 (56%) were female. In 20 (80%) of the P the cause for coronary angiography was ASA. All P referred for ASA had LVOTO and were on beta-blocker therapy (Table 1.). Median CFR was 2.5 [1.5-3] and median IMR was 19 [14-22], both within normal range. A total of 13 (44%) P had a reduced CFR and 5 (20%) of P had an increased IMR. 14 P (56%) had an altered CFR or IMR value, with the presence of a functional CMD phenotype in 10 P (40%) (Table 2). Angina was associated with a higher IMR (5.3, 95% CI - 0.05-10, p=0.053) and for each +1 increase in CCS a larger increase in the likelihood of a higher IMR was observed (CCS 1, +7 (95%CI 0.68 – 14); CCS 2, +9 (95%CI 4 – 14); CCS 3, 10 (95%CI 2 – 18)). A similar but non significant trend was observed for higher CCS correlating with lower CFR (Table 3). Conclusion In a prospective cohort of HCM P submited to invasive angiographic evaluation 56% had at least one invasive measure compatible with CMD. Angina, and a higher degree of anginal symptoms correlated positively with the presence of higher IMR and therefore with a higher level of CMD. In the future, we intend to correlate these findings with multimodality imaging/clinical outcomes.Patient characteristics and LR results

Children after kidney transplantation show severe cardiac alterations

Abstract Sudden cardiac death is among the most common causes of death in patients with chronic kidney diseases (CKD) after pediatric kidney transplantation (KTx), but defined diagnostic procedures identifying children at risk are not established. Echocardiographically detectable damage in the context of CKD has been described, but there are few data after KTx in childhood. The aim was to characterize structural and functional cardiac alterations on cardiac MRI (cMRI) and echocardiography in children after KTx and to elucidate the significance of diastolic dysfunction in this special context. 46 KTx recipients (mean age 16.0±3.5 years) and due to missing reference values 46 age- and sex-matched healthy controls were examined with non-contrast cMRI. Native T1 time (nT1), left ventricular mass z-score (LVMIz), ejection fraction (EF), global longitudinal strain (GLS) were measured. KTx recipients underwent comprehensive echocardiography: EF, mitral inflow (E-, A-wave), TDI e', E/e'-ratio, isovolumetric relaxation time (IVRT), pulmonary venous flow (PVFsys, PVFdia), atrial reversal (PVF-AR) and left atrial volume index (LAVI), left ventricular mass z-score (LVMz). Multivariable linear regression analysis (co-variates: age, sex, height) were used to show associations between cMRI and echo parameters. In cMRI KTx recipients had a siginficant higher nT1 than healthy controls (septal: 1198±49ms vs. 1155±23ms, p<0.0001; lateral: 1141±57ms vs. 1109±37ms, p=0.003). In KTx recipients, LVMIz was higher (0.1±1.1g/m2 vs. -0.3±0.7g/m2; p=0.026), GLS was lower than in healthy controls (-19± 2.1% vs. -20.3±2.7%, p=0.01). While based on cMRI 2 patients were diagnosed with left ventricluar hypertrophy (LVH), 11% (n=5) displayed LVH on echo. EF was preserved in all patients. However, in echocardiography, 90% (n=40) of the KTx recipients showed diastolic parameters out of the age-specific normal range (Fig.1) with changes in two or more diastolic parameters in half of the cohort. Associations with septal nT1 on cMRI could be demonstrated for septal E/e´ (ß=8.415, p=0.042), A-wave (ß=1.037, p=0.045), LAVI (ß=3.347, p=0.002) and PVF-AR (ß=2.945, p=0.021); associations with lateral nT1: septal E/e´ (ß=9.590, p=0.045) and LAVI (ß=3.393, p=0.009) (Fig. 2); 7 (15 %) had an elevated nT1 septal, lateral and E/e´ out of the normal range. Young KTx recipients show a high prevalence of diastolic dysfunction with preserved EF. Impaired diastolic function was associated with structural alterations reflecting myocardial fibrosis. Our findings suggest that a large number of children after KTx suffer from heart failure with preserved EF – an entity not yet defined in children but described for adults, in whom it is associated with sudden cardiac death. Further studies are needed to describe the clinical relevance of these findings, which gain explicit importance, as the prognosis of HFpEF in adults is improved by SGLT2i, a treatment option not yet considered in our high-risk patient group.

Noninvasive predictors of residual coronary microvascular dysfunction after elective percutaneous coronary intervention

Abstract Backgrounds Coronary computed tomographic angiography (CCTA) provides noninvasive assessments of coronary plaque morphologies and perivascular inflammation. Morphological features associated with residual coronary microvascular dysfunction (CMD) after elective percutaneous coronary intervention (PCI) remains unknown. Purpose This study aimed to examine prevalence and predictors of residual CMD and its phenotypes after elective PCI. Methods We investigated consecutive patients who were scheduled for elective fractional flow reserve (FFR)-guided PCI for de novo single lesions with pre-PCI CCTA data. Pre- and post-PCI comprehensive physiological assessments including coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) were performed by using pressure temperature sensor-tipped guidewire in all patients. Patients with periprocedural myocardial infarction were excluded. Residual CMD was defined as lesions with post-PCI coronary flow reserve (CFR) <2.0, which was further categorized as functional (IMR<25) or structural (IMR ≥25) CMD. Results A total of 198 de novo lesions in 198 patients were included in the final dataset. Pre- and post-PCI mean CFR were 1.79 [1.27, 2.53] and 2.72 [2.00, 4.04], respectively. Residual CMD was observed in 24.7% (49/198) of patients, categorized as functional (n=26) or structural (n=23). Patients with residual CMD showed older age, less frequent diabetes mellitus, current smoking and a culprit lesion in left anterior descending artery (LAD), and higher CCTA-defined calcium score in the culprit vessel compared with those in patients without residual CMD. Multivariable logistic regression analysis showed that age (adjusted odds ratio [OR]:1.04; 95% confidence interval [CI]: 1.00 to 1.08; p=0.04) and non-LAD (adjusted OR: 2.18; 95%CI: 1.03 to 4.63; p=0.04) were independently associated with residual CMD. In patients with residual CMD, patients with structural CMD tended to have more frequent diabetes mellitus (43.5% vs 19.2%, P=0.13) and atrial fibrillation (26.1% vs 7.7%) and showed significantly lower pericoronary adipose tissue attenuation (PCATA) in right coronary artery (RCA) by CCTA (-79.9 HU vs -74.6 HU, P=0.04) compared with patients with functional CMD. CCTA-detected epicardial fat volume and attenuation showed no significant differences between patients with residual functional CMD, those with residual structural CMD, and those without residual CMD. Multivariable analysis revealed that diabetes mellitus (adjusted OR: 5.18; 95%CI: 1.14 to 23.7; p=0.03) and PCATA in RCA (adjusted OR: 0.93; 95% CI: 0.85 to 1.00; p=0.05) were independently predictive of residual structural CMD. Conclusions Residual CMD was observed in approximately 25% of patients undergoing elective PCI. CCTA-defined calcium score and PCATA, along with clinical factors could be potential predictors of post-PCI residual CMD and its phenotypes.

Invasive assessment of coronary microvascular dysfunction with MACEs: a meta-analysis

Abstract Aims Although obstructive coronary artery disease (CAD) is considered a prerequisite for myocardial ischemia, it is established that abnormalities of coronary microcirculation may restrict myocardial perfusion in the absense of CAD. Coronary microvascular dysfunction (CMD) is likely associated with elevated risk for MACEs. We performed a meta-analysis of randomized controlled trials to determine the prognostic value of CMD, assessed by invasive techniques, in predicting cardiovascular endpoints in patients without epicardial CAD. Methods and results We identified all studies between 1 January 2000 and 1 December 2023, where coronary flow was invasively measured and clinical outcomes were reported. We included RCTs and all prospective and retrospective studies with a control group, which measured coronary flow reserve (CFR) and/or index of microcirculatory resistance (IMR), as assessed invasively. The endpoints were all-cause mortality and MACEs, including cardiovascular death, myocardial infarction, hospitalization for heart failure (HF) and coronary revascularization. Twenty-five articles enrolling a total of 9.800 subjects (mean age: 55.5±10.6 years) were included with a mean follow-up period of 37 months were eventually deemed eligible for our final analysis. Of these, 3.421 (34,9%) patients had CFR<2.5 and/or IMR>25, indicating CMD, while 6.379 (65,1%) subjects were found without CMD. The analysis of the pooled results demonstrated that the presence of CMD depicted by abnormal CFR and/or IMR was associated with a substantially higher risk for all-cause mortality during a median follow-up period of 3.2 years. The odds ratio for all-cause mortality in patients with CMD compared with those without CMD was 2.31 (95% CI: 1.62 - 2.54, p<0.01). A similar effect of abnormal CFR and IMR was also observed for cardiovascular morality (HR 2.47, 95% CI: 1.81 - 3.38, p<0.01). In addition, the composite of revascularization was also assessed in the total of the selected studies. In particular, the pooled analysis demonstrated a positive association of CMD with a higher future risk for revascularization (HR 1.87, 95% CI: 1.33 – 2.62, p<0.01). The composite of hospitalization for heart failure was also assessed. In addition, the pooled analysis demonstrated a positive association between CMD and hospitalization for HF (HR 2.50, 95% CI: 1.63 - 3.85, p<0.01).A similar effect of abnormal CMD was also observed for myocardial infraction (HR 1.73, 95% CI: 1.33 - 2.24). Elevated IMR (>40) seems to be to be prognostically more relevant than abnormal CFR in the setting of acute myocardial infarction. Conclusions CMD is associated with a nearly 3-fold increase in mortality and a 2-fold increase in major adverse cardiac events. Impaired coronary flow is strongly associated with increased risk of all-cause mortality and MACEs. Future studies and randomized controlled trials are needed to identify strategies to diagnose and treat CMD.

Understanding perioperative risk determinants in carotid endarterectomy: the impact of compromised circle of Willis morphology on inter-hemispheric blood flow indices based on intraoperative internal carotid artery stump pulse pressure and backflow patterns.

Carotid artery stenosis (CAS) often requires surgical intervention through carotid endarterectomy (CEA) to prevent stroke. Accurate cerebrovascular risk assessments are crucial in CEA, as poor collateral circulation can lead to insufficient interhemispheric blood flow compensation, resulting in ischemic complications. Therefore, understanding perioperative risk determinants is vital. This study aims to determine the impact of compromised circle of Willis (CoW) morphology on inter-hemispheric blood flow, focusing on indices based on intraoperative internal carotid artery stump pulse pressure and backflow patterns. In 80 CAS patients who underwent CEA, preoperative CT angiography for CoW was conducted. Patients were categorized into five subgroups based on their CoW anatomy and three additional groups based on intraoperative internal carotid artery (ICA) stump backflow patterns evaluated by the surgeon. Continuous blood pressure signals, including systolic, diastolic, mean, and pulse pressure values, were recorded during the procedure. The relationship between CoW anatomical variants and the systolic and diastolic segments of the averaged pressure waveforms, particularly diastolic pressure decay, was analyzed. The correlation between CoW anatomy and stump backflow intensity was also examined. Significant variability in ICA stump backflow and pressure values was evident across CoW variants. Patients with compromised CoW morphology exhibited weaker backflow patterns and lower ICA stump pulse pressure values, consistent with impaired interhemispheric blood flow. Notably, ICA stump diastolic pressure decay was consistent across most CoW variant groups, indicating developed collateral circulation in cases with CoW anomalies. Thus, impaired CoW integrity is associated with compromised interhemispheric blood flow indices based on intraoperative ICA stump pulse pressure and backflow patterns during CEA. Integrating intraoperative pulse waveform analysis with preoperative CT angiography provides a more detailed assessment of cerebrovascular risk, guiding the selective use of shunts. This combined approach may improve surgical outcomes and patient safety by identifying patients at increased risk of perioperative neurological events due to CoW anomalies.

Mechanical recycling of polyamide 6 and polypropylene for automotive applications

AbstractThis study investigates the mechanical recycling of polyamide 6 (PA6) from discarded fishing nets and polypropylene (PP) from automotive battery scraps and household waste for automotive applications. The mechanical properties of both materials were evaluated through tensile, impact, and thermal testing, revealing that recycled PA6 (r‐PA6) and recycled PP (r‐PP) can achieve mechanical performance similar to virgin materials. Recycled PA6 was reinforced with 30% glass fiber (GF), significantly enhancing its tensile strength from 70 to 170 MPa, comparable with virgin PA6's (76 MPa). Furthermore, the tensile modulus of r‐PA6 increased from 7720 to 8500 MPa. Recycled PP was compounded with thermoplastic elastomers (TPE) and fillers, such as calcium carbonate (CaCO₃) and talc, improving its impact strength from 5 to 18 KJ/m2 and improving thermal stability, with a heat deflection temperature (HDT) reaching 95°C. The optimized formulations for r‐PP, particularly from automotive battery scrap, achieved a melt flow index (MFI) of 12–16 g/10 min, preventing molding defects. This study highlights the importance of controlled thermal treatments, appropriate additive use, and accurate processing conditions in producing high‐quality recycled polymer compounds.Highlights Recycled PA6 reinforced with 30% GF achieves a tensile strength of 170 MPa. Thermal treatment increases the tensile modulus of r‐PA6 to 8500 MPa, similar to virgin PA6. Incorporating TPE improves the impact strength of r‐PP to 18 KJ/m2. Calcium carbonate and talc enhance the thermal stability of r‐PP to 95°C. The melt flow index of r‐PP optimized to 12–16 g/10 min for better moldability.

Linking curve number with environmental flows: a novel approach.

Change in flow regime is one of the major reasons which influence the services offered by rivers and integrity of their aquatic ecosystems requiring certain amount of flow in the river known as environmental flow. In this study, the environmental flows described by Tennant's method are correlated with a very versatile index defined in terms of Curve Number (CN) that incorporates hydrometeorological and geomorphological characteristics of catchment. Parameter CN is commonly known to be closely related with catchment characteristics (viz., land use, soil type, etc.). The rainfall-runoff data of 17 catchments from five major Indian river basins (i.e., Brahmani-Baitarani, Godavari, Mahanadi, Mahi, and Narmada) of low flow season (October-June) are used to derive the relationship between percentage of average annual flow (%AAF) and CN. The %AAF is seen to increase linearly with increasing CN, and vice versa, for all catchments and the correlation (R) is found to be greater than 0.7 for 16 (out of 17) catchments. The correlation between %AAF and CN is maximum for Dhariawad (R2 = 0.899) and Baronda (R2 = 0.814) catchments, indicating excellent relationship between %AAF and CN, which can be useful for the environmental flow prediction based on catchment characteristics. The existence of such a relationship is further strengthened by the relation established between the standard normal deviate of CN and the Standard Flow Index (SQI), a variation of %AAF, using the same field data.

Recycled polypropylene/crystalline cellulose composites obtained using polypropylene functionalized with maleinized hyperbranched polyol polyester as compatibilizing and plasticizing agent

AbstractRecycled polypropylene (rPP)/crystalline cellulose (rPP/CC) composites are promising alternatives for reducing the detrimental environmental consequences of virgin PP. However, the incompatibility of the rPP/CC composites hinders their widespread application. In this study, PP functionalized with maleinized hyperbranched polyol polyester (PP‐g‐MHBP) was used as a compatibilizing and plasticizing agent for the rPP/CC composites. Furthermore, the effect of PP‐g‐MHBP content on the rheological, thermal, morphological, and mechanical properties of the rPP/CC composites was evaluated. The composites were prepared at a mixing speed of 50 rpm for 7 min and the PP‐g‐MHBP content was varied between 0 and 20 wt%. The torque stabilization time was less than 1 min. The activation energy of flow () decreased with increasing PP‐g‐MHBP content, with its values ranging from 0.78 × 102 to 1.42 × 102 kcal.mol−1. The flow index () followed the opposite trend with values ranging from 0.55 ± 0.0030 to 0.85 ± 0.0010. PP‐g‐MHBP enhanced the processability, thermal stability and conductivity. The crystallinity, interactions between rPP and CC, and tensile modulus of the rPP/CC composites were also enhanced. Furthermore, it reduced the agglomeration of CC particles.Highlights The torque stabilization was lowest for all composites. The composites displayed low activation energy of flow. Recycled polypropylene and crystalline cellulose exhibited good interaction. The plasticizing effect was higher than that of compatibilization. The thermal stability and mechanical properties of the composites improved.

Study of Mechanical and Thermal Properties of Environmentally Friendly Composites from Beer Bagasse.

The influence of bagasse fibres from beer manufacturing in mechanical, thermal, and rheological properties of three polymers (BioPE, PLA, and PP) has been studied in order to develop new environmentally friendly biocomposites for injection moulding applications. Totals of 10 wt%, 20 wt%, and 30 wt% of bagasse fibre (BSG) were added to the polymers by extrusion compounding, adding specific compatibilising additives, and injected samples were mechanically characterised by tensile, Charpy impact, and hardness tests. In addition, the fractures obtained after the impact test were observed using scanning electron microscopy (SEM) to assess the compatibility matrix filler. Characterisation of the thermal properties is also carried out by using differential scanning calorimetry (DSC) and thermogravimetry (TGA). Additionally, melt flow index of the biocomposites is also studied. An increase in the rigidity of the BioPE and PP composites was produced with the increase in BSG content, dealing with a decrease in maximum strain and impact resistance; whereas, in the filled BGS PLA biocomposites, Young's modulus was lower than that of the PLA material, improving the ductility of the PLA-BGS formulations. Compatibilisation effect was, therefore, different in the nine developed formulations, and the BGS content also influenced their thermal, mechanical, and rheological behaviours.

Dynamic behavior of melt electrospinning of blended polypropylene

Melt electrospinning is a promising process for fiber production without the need for solvents and with potential applications in various fields. In this study, we investigated the dynamic behavior of melt electrospinning under different blending ratios and process conditions. We used high melt flow index polypropylene and low molecular weight polypropylene, which were blended to lower the melt viscosity, and fibers were successfully manufactured through the melt electrospinning process. The effects of blending ratio and applied voltage on jet and drop formation, as well as fiber morphology, were examined. The results showed that blending low-molecular-weight polypropylene significantly influenced the jet and drop areas, leading to fluctuations in jet morphology. The size of the applied high voltage also had a high effect on the fiber diameter. Additionally, the viscosity reduction achieved through blending allowed for continuous jet formation and improved fiber production. These results provide valuable insights into controlling the process parameters and blending ratios in melt electrospinning, enabling the establishment of stable electrospinning conditions and precise control of fiber diameter.

A framework for analyzing the most relevant indicators of ecohydrology in a changing environment

ABSTRACT Human activities and climatic changes have altered the hydrological ecosystem of the Min River Basin and affected in-river biodiversity. In this paper, the year of abrupt hydrological change was identified using multiple tests, and the drivers of ecohydrological change were quantified in conjunction with the Budyko coupled hydrothermal equilibrium theory. Combined with ecological flow indicators (ecological surplus (ES) and ecological deficit (ED)) calculated based on discharge hydrographs and multiple hydrological indicators (ES/ED), the degree of river hydrological alteration in the Min River Basin was comprehensively evaluated, and its impacts on in-river biodiversity analyzed. The results of the study showed that: (1) according to the Budyko theory, the influence of human activities on the runoff changes in the Min River Basin reached 56.80%, which was the main influence factor, followed by climatic factors (41.56% for precipitation and 1.64% for evapotranspiration); (2) dam construction has generally resulted in an increase in seasonal ES and a decrease in seasonal ED; (3) the combination of the ecological flow indexes with the ecologically relevant hydrological indicators not only reduces the redundancy between the parameters, but also reflects the essential hydrological information and ecological connotations, and it is an effective method for evaluating ecohydrological mechanisms.

Effect of toughening agent and flame‐retardant additives on the recycled polypropylene/oil palm empty fruit bunch laminated composites

AbstractThe increasing awareness of the environmental problems caused by the use of plastics has led to a demand for sustainable materials. The concept of turning waste into wealth has been considered in the study where the waste materials are value‐added into new composite materials that are recyclable, durable, and fire‐resistant. This effort aims to meet global environmental goals and the demand for high‐performance and sustainable building materials. The purpose of this current study is to develop laminated composites based on the combination of recycled plastic and oil palm empty fruit bunch (OPEFB). The addition of various loading of ammonium polyphosphate (APP) and 6 wt% of ethylene vinyl acetate (EVA) in the formulation was considered to enhance the performance of the composite laminates. The rPP and additives were compounded using a two‐roll mill. Then the rPP sheet and OPEFB were laminated using compression molding techniques. Results showed that rPP with addition of 30 wt% APP and 6 wt% EVA exhibited the highest thermal stability and the lowest melt flow index (MFI) value compared to other samples. Composites with 20 wt% APP and 6 wt% EVA showed 56% increase in flexural properties and 33% increase in impact strength compared to that of rPP/OPEFB composite sample without EVA. Addition of 30 wt% in recycled PP and OPEFB demonstrated self‐extinguished properties when exposed to fire compared to other samples. These findings indicated that rPP/OPEFB laminated composites with the addition of APP and EVA have a potential to be used in applications that require good strength and fire performance. The use of rPP/OPEFB composites with addition of APP and EVA has a potential to reduce virgin plastic consumption and agriculture material waste and establishing an environmentally friendly material for construction sector.Highlights Additives included in recycled PP enhance its thermal stability and reduce MFI. Recycled PP with OPEFB composite self‐extinguished at 30 wt% APP. The highest flexural strength is shown by composite laminates with 20 wt% APP and 6 wt% EVA. rPP/OPEFB laminates are ideal for building materials.

Impact of Runner Size, Gate Size, Polymer Viscosity, and Molding Process on Filling Imbalance in Geometrically Balanced Multi-Cavity Injection Molding.

The injection molding process is one of the most widely used methods for polymer processing in mass production. Three critical factors in this process include the type of polymer, injection molding machines, and processing molds. Polypropylene (PP) is a widely used semi-crystalline polymer due to its favorable flow characteristics, including a high melt flow index and the absence of a need for a mold temperature controller. Additionally, PP exhibits good elongation and toughness, making it suitable for applications such as box hinges. However, its tensile strength is a limitation; thus, glass fiber is added to enhance this property. It is important to note that the incorporation of glass fiber increases the viscosity of PP. Multi-cavity molds are commonly employed to achieve cost-effective and efficient mass production. The filling challenges associated with geometrically balanced layouts are well documented in the literature. These issues arise due to the varying shear rates of the melt in the runner. High shear rate melts lead to high melt temperatures, which decrease melt viscosity and facilitate easier flow. Consequently, this results in an imbalanced filling phenomenon. This study examines the impact of runner size, gate size, polymer viscosity, and molding process on the filling imbalanced problem in multi-cavity injection molds. Tensile bar injection molding was performed using conventional injection molding (CIM) and microcellular injection molding (MIM) techniques. The tensile properties of the imbalanced multi-cavity molds were analyzed. Flow length within the cavity served as an indicator of the filling imbalance. Additionally, computer simulations were conducted to assess the shear rate's effect on the runner's melt temperature. The results indicated that small runner and gate sizes exacerbate the filling imbalance. Conversely, glass fiber-filled polymer composites also contribute to increased filling imbalance. However, foamed polymers can mitigate the filling imbalance phenomenon.

Development, Optimization, and Evaluation of New Gel Formulations with Cyclodextrin Complexes and Volatile Oils with Antimicrobial Activity.

This study aimed to develop and evaluate hydrogels containing a cyclodextrin complex with clove essential oil and other free volatile oils with antimicrobial properties (tea tree and rosemary essential oils), focusing on their pharmaco-technical and rheological characteristics. The formulations varied in the Carbopol 940 (a hydrophilic polymer) and volatile oils' concentrations. Rheological analysis indicated that the gels displayed pseudoplastic behavior, with the flow index (n) values below 1, ensuring appropriate consistency and handling. The results showed that increasing the Carbopol concentration significantly enhanced the yield stress, consistency index, and viscosity, with gel B, containing 1% Carbopol, 1.5% tea tree essential oil, and 1.5% rosemary essential oil, demonstrating optimal stability and rheological properties. At the same time, the concentration of volatile oils was found to modulate the gels' flow parameters, but their effect was less pronounced than that of the gel-forming polymer. Antimicrobial testing revealed that both gel B and gel E (containing 1% Carbopol, 2% tea tree essential oil, and 2% rosemary essential oil) exhibited antimicrobial activity against Gram-positive, Gram-negative bacteria, and Candida spp., with gel E showing superior efficacy against Candida tropicalis. The antimicrobial effects were likely influenced by the higher concentrations of tea tree and rosemary essential oils in gel E. Overall, the study demonstrates that the concentration of Carbopol 940 primarily determines the gel's rheological behavior, while volatile oil concentration modulates antimicrobial effectiveness.

Applied Investigation of Methyl, Ethyl, Propyl, and Butyl Mercaptan as Potential Poisons in the Gas Phase Polymerization Reaction of Propylene.

The polypropylene (PP) synthesis process is crucial in the plastics industry, requiring precise control as it directly impacts the catalytic activity and the final product's performance. This study investigates the effects of trace amounts of four different mercaptans on the polymerization of propylene using a fourth-generation Ziegler-Natta (ZN) catalyst. Various concentrations of these mercaptans were tested, and results showed that their presence significantly reduced the melt flow index (MFI) of the final PP. The most notable MFI decrease occurred at 37.17 ppm of propyl mercaptan and 52.60 ppm of butyl mercaptan. Methyl and ethyl mercaptan also reduced the MFI at lower concentrations, indicating that mercaptans act as inhibitors by slowing down the polymerization process and reducing the fluidity of molten PP. The highest MFI increase was observed at lower concentrations of each mercaptan, suggesting that smaller molecular inhibitors require less concentration. This trend was also seen in the catalyst's productivity, where lower concentrations of methyl mercaptan reduced PP production more effectively than higher concentrations of butyl mercaptan. Fourier transform infrared spectroscopy (FTIR) identified interactions between the mercaptans and the ZN catalyst. Computational analysis further supported these findings, providing insights into the molecular interactions and suggesting possible inhibition mechanisms that could impact the final properties of polypropylene.

Microcirculatory Perfusion Disturbances During Veno-Arterial Extracorporeal Membrane Oxygenation: ASystematic Review.

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is used in case of potentially reversible cardiac failure and restores systemic hemodynamics. However, whether this is followed by improvement of microcirculatory perfusion is unknown. Moreover, critically ill patients have possible pre-existing microcirculatory perfusion disturbances. Therefore, this review provides an overview of alterations in sublingual microcirculatory perfusion in critically ill adult patients receiving VA-ECMO support. Pubmed, Embase (Ovid), Cochrane Central Register of Controlled Trials, and Web of Science were systematically searched according to PRISMA guidelines. Studies reporting sublingual microcirculatory perfusion measurements in adult patients supported by VA-ECMO were included. Outcome parameters included small vessel density (SVD), perfused vessel density (PVD), perfused small vessel density (PSVD), proportion of perfused vessels (PPV), microvascular flow index (MFI) and the heterogeneity index (HI). The protocol was registered at PROSPERO (CRD42021243930). The search identified 1215 studies of which 11 were included. Cardiogenic shock was the most common indication for VA-ECMO (n=8). Three studies report increased PSVD, PPV, and MFI 24 hours after initiation of ECMO compared to pre-ECMO. Nonetheless, microcirculatory perfusion stabilized thereafter. Four out of four studies showed higher PSVD and PPV in survivors compared to non-survivors. Over time, survivors showed recovery of microcirculatory perfusion within hours of initiation of ECMO, whereas this was absent in non-survivors. Notwithstanding the limited sample, VA-ECMO seems to improve microcirculatory perfusion shortly after initiation of ECMO, especially in survivors. Further research in larger cohorts is needed to clarify the longitudinal effects of ECMO on microcirculatory perfusion.

Investigation of Rheological Properties of Molten Materials for Dripping Pills Based on Imaging Monitoring.

Rheological properties, as critical material attributes (CMAs) of solid dispersion drugs such as dripping pills, affect the melting, dispersion, and solidification. Therefore, characterization and assessments of rheological properties in the pharmaceutical process are important in enhancing drug stability and bioavailability. The study aimed to develop a method for analyzing the rheology of molten materials, assessing their consistency and how rheological properties affect the dripping process and pills quality. The rheological behavior of molten materials composed of Ginkgo biloba leaf extract (GBE) and polyethylene glycol (PEG) 4000 was characterized. Batch consistency of molten materials was evaluated. Image monitoring technology was utilized to capture and process images of the droplet formation process. We established the relationship between the rheological properties of molten materials and various attributes. The quality consistency of molten materials was evaluated, with 12 batches showing similarity above 0.8. The MLR models showed strong correlations (R2 > 0.80) between rheological properties and evaluation attributes. The rheological properties, including consistency coefficient, flow index, and viscosity at 80°C, were identified as critical rheological properties of the molten materials. Rheological property differences of molten materials have an impact on the morphology of droplet and quality performance. A rheological method was established, enabling quality consistency evaluation of molten materials in dripping pills. This study revealed the influence of rheological properties on droplet formation process and dripping pills quality, providing a reference for researches on material attributes control of other traditional Chinese medicine dripping pills.

Diffuse correlation tomography: a technique to characterize tissue blood flow abnormalities in benign and malignant breast lesions

Accurate assessment and quantification of neoangiogenesis associated with breast cancer could be potentially used to improve the sensitivity and specificity of non-invasive diagnosis, as well as predict outcomes and monitor treatment effects. In this study, we adapted an emerging technology, namely diffuse correlation tomography (DCT), to image microvascular blood flow in breast tissues and evaluate the potential for discriminating between benign and malignant lesions. A custom-made DCT system was designed for breast blood flow imaging, with both the source-detector array and reconstruction algorithm optimized to ensure precise imaging of breast blood flow. The global features and local features of three-dimensional blood flow images were extracted from the relative blood flow index (rBFI), which was obtained from most of the breasts targeted to the lesion. A total of 37 women with 19 benign and 18 malignant lesions were included in the study. Significant differences between malignant and benign groups were found in 12 image features. Moreover, when selecting the lesion mean relative blood flow index (MrBFI) as a single indicator, the malignant and benign tumors were discriminated with an accuracy of 89.2%. The blood flow features were found to successfully identify malignant and benign tumors, suggesting that DCT, as an alternate functional imaging modality, has the potential to be translated into clinical practice for diagnosis and assessment of breast cancers. There is potential to reduce the need for biopsy of benign lesions by improving the specificity of diagnostic imaging, as well as monitoring response to breast cancer treatment.

Encapsulated papillary carcinoma of breast: Comparative study of multimodal ultrasound manifestations and pathological features.

To investigate the conventional ultrasound (US), contrast-enhanced ultrasound (CEUS) manifestations and the corresponding histopathological characteristics of patients diagnosed with breast encapsulated papillary carcinoma (EPC) and to explore the value of CEUS in diagnosis of EPC. The clinical, pathological, US, and CEUS features of 16 patients (17 lesions) with EPC confirmed by postoperative histopathology were retrospectively analyzed. EPC was prevalent in the postmenopausal women. The majority of conventional US images of EPC showed complex cystic and solid masses with circumscribed margins (70.6%), enhanced posterior echo (94.1%), no sonographic calcification (88.2%), rich blood flow in the solid components within lesions (70.6%) on Color Doppler flow imaging, and high resistance index of blood flow (94.1%). Moreover, CEUS showed mainly centripetal hyperenhancement of the solid components within the lesions with irregular outline, and the enhancement area of the whole masses was essentially the same as the B-mode US area. EPC typically presents as a complex cystic and solid mass. CEUS is helpful to clarify the extent of the solid component and facilitate preoperative core-needle biopsy. A comprehensive evaluation by CEUS is valuable for diagnosing EPC and combining it with clinical features are helpful to further improve the diagnosis of this rare kind of breast cancer.

Automated Quantification of Simple and Complex Aortic Flow Using 2D Phase Contrast MRI

(1) Background and Objectives: Flow assessment using cardiovascular magnetic resonance (CMR) provides important implications in determining physiologic parameters and clinically important markers. However, post-processing of CMR images remains labor- and time-intensive. This study aims to assess the validity and repeatability of fully automated segmentation of phase contrast velocity-encoded aortic root plane. (2) Materials and Methods: Aortic root images from 125 patients are segmented by artificial intelligence (AI), developed using convolutional neural networks and trained with a multicentre cohort of 160 subjects. Derived simple flow indices (forward and backward flow, systolic flow and velocity) and complex indices (aortic maximum area, systolic flow reversal ratio, flow displacement, and its angle change) were compared with those derived from manual contours. (3) Results: AI-derived simple flow indices yielded excellent repeatability compared to human segmentation (p < 0.001), with an insignificant level of bias. Complex flow indices feature good to excellent repeatability (p < 0.001), with insignificant levels of bias except flow displacement angle change and systolic retrograde flow yielding significant levels of bias (p < 0.001 and p < 0.05, respectively). (4) Conclusions: Automated flow quantification using aortic root images is comparable to human segmentation and has good to excellent repeatability. However, flow helicity and systolic retrograde flow are associated with a significant level of bias. Overall, all parameters show clinical repeatability.