Slow Flow Research Articles

The forgotten forests: Incorporating temperate peat‐forming wet woodlands as nature‐based solutions into policy and practice

Abstract Peat‐forming wet woodlands (forested wetlands) are naturally occurring carbon‐dense ecosystems that have considerable potential to form an important part of net zero woodland establishment and peatland strategies, as well as provide crucial co‐benefits to restore biodiversity and regulate hydrological systems. Despite their potential, temperate peat‐forming wet woodlands have been widely lost, are critically understudied and are being overlooked in land‐use strategies. Unlike temperate ‘dry’ woodlands, some wet woodlands are peat forming and can store large amounts of carbon below‐ground in peat in addition to the carbon in the tree biomass. The complex structure of these peat‐forming wet woodlands creates high abiotic heterogeneity, resulting in a wide variety of microhabitats to support high levels of biodiversity, and this structural complexity can also increase water storage in the landscape and slow flood flows, providing natural flood protection. Co‐written by experts in academia and UK Government, we highlight critical knowledge gaps in our understanding of peat‐forming wet woodlands that, once addressed, could form the basis for radical changes to their inclusion in net zero and land‐use policies. Policy and practice implications: The significant role that peatland restoration has to play in reaching net zero presents an immediate policy opportunity to consider the full range of ecosystems to achieve net zero targets, while protecting and enhancing socio‐ecological sustainability. In co‐writing this paper, our aim is to stimulate discussion and sharing of knowledge between those involved in research, policy and practice in order to strengthen the evidence base for peat‐forming wet woodland re‐establishment and future management. We call on researchers, policymakers and land managers to take temperate wet woodlands from understudied and overlooked, to integrated ecosystems that hold great promise in the contributions they can make as nature‐based solutions.

Significance of fragmented QRS and predictors of outcome in ST-elevation myocardial infarction

Abstract Background: Fragmented QRS (fQRS) might be associated with certain characteristics in ST-elevation myocardial infarction (STEMI) patients and inhospital adverse events. Materials and Methods: A sum of 500 patients were gone over retrospectively. Patients with STEMI, all undergone percutaneous coronary intervention, were grouped as fQRS (−) and fQRS (+). Characteristics of the patients, major adverse cardiac event (MACE), death in hospital, nonfatal myocardial infarction (MI), stent thrombosis, slow flow myocardial perfusion, development of ventricular tachycardia (VT) and fibrillation, cardiogenic shock and cardiopulmonary arrest were filtered. Results: FQRS (−) group was composed of 207 patients whose mean age was 61.1 ± 12.1, whereas 293 patients were there in fQRS (+) with a mean age of 66.7 ± 10.6 (P < 0.001). Thrombolysis in MI (TIMI) (P < 0.01), the global registry of acute coronary events (GRACE) (P < 0.01) scores, white blood cell count, neutrophil/lymphocyte ratio, MACE and the ratio of death in hospital and VT in the hospital were significantly higher in fQRS (+) group (P < 0.001, for remaining all). In multivariate logistic regression analysis, TIMI scores above 2 and GRACE scores above 109 were determined as independent predictors of MACE in the entire patient group (odds ratio [OR]: 2.022; 95% confidence interval [CI]; 1.321–3.424, P = 0.003; OR: 1.712; 95% CI: 1.156–2.804, P = 0.008). Conclusion: FQRS (+) and fQRS (−) patients markedly differ from each other in terms of certain demographic and clinical features and TIMI and GRACE scores have a significant predictive value for MACE in all STEMI patients’ group.

Pattern of Coronary Angiography in Young Adults versus Older Adults Presented by Coronary Artery Disease in Correlation to Their Risk Factors with 1-year Follow-up of Their Clinical Outcome

Abstract Background: Coronary artery disease (CAD) is a leading cause of mortality worldwide, with varying patterns and risk factors across different age groups. While CAD is common in older adults, data on young adults are limited, with traditional risk factors and familial history playing a significant role in early disease development. The purpose of this study was to compare the coronary angiographic patterns in young adults (<40 years) and older adults (≥40 years) presented with CAD, assess the correlation with risk factors, and monitor clinical outcomes after 1 year. Patients and Methods: This retrospective cohort study was conducted at the National Heart Institute, including 2204 consecutive patients undergoing coronary angiography and/or percutaneous coronary intervention for CAD from January 2019 to January 2020. Patients were divided into two groups based on age: group A (<40 years) and Group B (≥40 years). Angiographic findings, risk factors, and clinical outcomes were assessed and compared. Results: Group B had significantly higher rates of hypertension (63.6% vs. 22.2%, P < 0.001), diabetes (53.5% vs. 24.1%, P < 0.001), and female gender (29% vs. 11.1%, P < 0.001) compared to Group A. Group A showed higher smoking rates (70.4% vs. 46.5%, P < 0.001) and positive family history (42.6% vs. 4.4%, P < 0.001). Angiographic findings revealed higher rates of single-vessel affection, coronary ectasia, aneurysm, and slow flow phenomenon in Group A, whereas Group B demonstrated more bifurcation lesions, chronic total occlusion, and calcification. Conclusions: This study highlights the need for age-specific approaches in managing CAD, with younger patients showing early disease onset and older patients exhibiting more complex disease. Tailored cardiovascular care is essential, focusing on lifestyle modifications in younger adults and managing metabolic conditions in older adults.

The triglyceride-glucose index as a predictive marker for coronary slow flow phenomenon.

The triglyceride-glucose index (TyG) has been proposed as a marker of insulin resistance (IR) and has shown associations with cardiovascular diseases. This study aimed to investigate the relationship between the TyG and the coronary slow flow phenomenon (CSFP) and explore the index's potential as a predictor of this condition. A total of 187 patients who underwent coronary angiography were included; of these, 91 patients were diagnosed with CSFP, and 96 patients with normal coronary flow served as a control group. The TyG was calculated using fasting triglyceride and glucose levels. The results showed that the TyG was significantly higher in the CSFP group compared with the control group (p < 0.001). Additionally, the TyG exhibited a moderate positive correlation with the thrombolysis-in-myocardial-infarction frame count in coronary arteries (p < 0.001). A multivariate logistic regression analysis revealed that the TyG, along with gender, ejection fraction, and uric acid, remained significant predictors of CSFP (p < 0.05). This study's findings suggest that the TyG may serve as a useful marker for identifying individuals at risk of CSFP and provide insights into the potential role of IR in its pathophysiology.

Diagnostic value of stress myocardial perfusion imaging in combination with computed tomography angiography for coronary slow flow

Abstract Introduction: To date, there are few reports on computed tomography angiography (CTA) in combination with stress myocardial perfusion imaging (SMPI) in the diagnosis of coronary slow flow (CSF). Methods: A total of 62 patients with suspected CSF who were scheduled to undergo CTA, SMPI and coronary angiography (CAG) from June 2019 to June 2021 were selected. With the results of CAG as the gold standard, the value of CTA plus SMPI in the diagnosis of CSF was analyzed. Results: Of the 62 patients, 52 (83.87%) were diagnosed with CSF by CAG. The results of the Kappa consistency test showed that SMPI alone, CTA alone and SMPI plus CTA had 0.565, 0.396 and 0.881 consistency, respectively, with CAG in the diagnosis of CSF. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of SMPI plus CTA in the diagnosis of CSF were 98.08% (51/52), 90.00% (9/10), 96.47% (60/62), 98.08% (51/52), and 90.00% (9/10), respectively, all higher than those of SMPI or CTA alone (P&lt;0.05). The areas under the receiver operating characteristic curves of SMPI alone, CTA alone and SMPI plus CTA in the diagnosis of CSF were 0.754, 0.771 and 0.940, respectively. Conclusion: CTA and SMPI have high diagnostic values for CSF, and the results of their combination have high consistency with those of CAG.

Modelling hydrologic processes of a karst region in Southern China using coupled hydrological models

ABSTRACT In the karst area, the epikarst increases the infiltration of rainfall and the depressions and conduits make water exchange frequently between surface rivers and karst aquifers. To improve simulation accuracy, we proposed the Soil and Water Assessment Tool-Genetic Algorithm-Back Propagation (SWAT-GA-BP) model. Also, the SWAT-tank model was created to elaborate the runoff processes in different karst systems. Furthermore, we designed three scenarios to study the influence of land use changes on runoff. The Zuo River Basin was selected as a case study. Compared to SWAT, the determination coefficient of the SWAT-GA-BP increased by 4.8% and the Nash-Sutcliffe efficiency increased by 4.9%; the rapid flow accounted for more than 50% of the total runoff, and the slow flow for less than 10%; the contribution of the land use changes was 10.80% from 2008 to 2012 and 5.57% from 2013 to 2017. Therefore, the effect of land use change on runoff should not be ignored.

Hydrogeological structures of karst features using hydrographs in an underground river basin formed in a peak cluster depression, southwest China

Understanding of the hydrological behaviors in different karst features is crucial for evaluating the hydrological storage and transfer functions of a karst system. In this study, the Maocun karst underground river system, characterized by typical karst features, was selected as the research area in the southwest region of China. The main objectives of this research are to analyze the hydrogeological structure characteristics of each karst feature and assess water storage capacity in different aquifer media. Frequency distribution curve (FDC) of electrical conductivity (EC) values revealed that recharge sources in the five karst features differed and varied according to the amount of precipitation. All hydrographs of water levels in five karst features were divided into three periods due to the presence of triple aquifer media in the basin. The spatial structure of each feature was interpreted by analyzing the variation characteristics of recession exponential coefficients (λ). Additionally, the ratios of fissure water, fracture water, and conduit water sources were calculated based on the recession curves of water levels. Results showed that fast water flow had the highest proportion in the relatively open subsystem located upstream, while fracture water flow had the lowest proportion. The slow water flow was the main pattern of water storage in the basin. Values of EC in water decreased with a well-connected spatial structure and high hydraulic conductivity. There were significant differences in the values of EC among conduit water, fracture water, and matrix water. These values were calculated using mathematical relationships between EC and water level hydrographs. The results indicated that the EC values in matrix water exceeded 200 μS/cm, while EC values in conduit water/channel water were below 100 μS/cm. Finally, hydrogeological conceptual models were constructed for five karst features based on the depletion characteristics of the aquifer media during each recession period. These characteristics were interpreted using variation curves of EC and hydrographs of water levels. These findings not only elucidated the characteristics of hydrogeological structures in multiple karst features, but also had significant implications for the assessment of karst water sources.

Patient-specific left atrium contraction quantification associated with atrial fibrillation: A region-based approach

Background and objectivesAtrial fibrillation (AF) is a widespread cardiac arrhythmia that significantly impacts heart function. AF disrupts atrial mechanical contraction, leading to irregular, uncoordinated, and slow blood flow inside the atria which favors the formation of clots, primarily within the left atrium (LA). A standardized region-based analysis of the LA is missing, and there is not even any consensus about how to define the LA regions. In this study we propose an automatic approach for regionalizing the LA into segments to provide a comprehensive 3D region-based LA contraction assessment. LA global and regional contraction were quantified in control subjects and in AF patients to describe mechanical abnormalities associated with AF. MethodsThe proposed automatic approach for LA regionalization was tested in thirteen control subjects and seventeen AF patients. After dividing LA into standard regions, we evaluated the global and regional mechanical function by measuring LA contraction parameters, such as regional volume, global and regional strains, regional wall motion and regional shortening fraction. ResultsLA regionalization was successful in all study subjects. In the AF group compared with control subjects, results showed: a global impairment of LA contraction which appeared more pronounced along radial and circumferential direction; a regional impairment of radial strain which was more pronounced in septal, inferior, and lateral regions suggesting a greater reduction in mechanical efficiency in these regions in comparison to the posterior and anterior ones. ConclusionAn automatic approach for LA regionalization was proposed. The regionalization method was proved to be robust with several LA anatomical variations and able to characterize contraction changes associated with AF.

Recurrent syncope due to ischemia with non-obstructive coronary artery disease: a case report

BackgroundIschemia with non-obstructive coronary artery disease is a prevalent form of ischemic heart disease. The majority of ischemia with non-obstructive coronary artery disease cases are attributed to underlying factors such as coronary microvascular dysfunction (CMD) and/or coronary artery spasm. Ischemia with non-obstructive coronary artery disease can present with various clinical manifestations. Recurrent syncope is an atypical complaint in patients with ischemia with non-obstructive coronary artery disease.Case presentationThis case report describes the presentation of a 58-year-old Chinese male patient who experienced repeated episodes of syncope. The syncope was found to be caused by concomitant coronary artery spasm and presumptive coronary microvascular dysfunctionc suggested by “slow flow” on coronary angiography. The patient was prescribed diltiazem sustained-release capsules, nicorandil, and atorvastatin. During the three-month follow-up conducted on our outpatient basis, the patient did not experience a recurrence of syncope.ConclusionThis study highlights the importance of considering ischemia with non-obstructive coronary artery disease as a potential cause of syncope in the differential diagnosis. It emphasizes the need for early diagnosis of ischemia with non-obstructive coronary artery disease to facilitate more effective management strategies.

Measuring CSF shunt flow with MRI using flow enhancement of signal intensity (FENSI).

To develop and validate a noninvasive imaging technique for accurately assessing very slow CSF flow within shunt tubes in pediatric patients with hydrocephalus, aiming to identify obstructions that might impede CSF drainage. A simulation of shunt flow enhancement of signal intensity (shunt-FENSI) signal is used to establish the relationship between signal change and flow rate. The quantification of flow enhancement of signal intensity data involves normalization, curve fitting, and calibration to match simulated data. Additionally, a phase sweep method is introduced to accommodate the impact of magnetic field inhomogeneity on the flow measurement. The method is tested in flow phantoms, healthy adults, intensive care unit patients with external ventricular drains (EVD), and shunt patients. EVDs enable shunt-flow measurements to be acquired with a ground truth measure of CSF drainage. The flow-rate-to-signal simulation establishes signal-flow relationships and takes into account the T1 of draining fluid. The phase sweep method accurately accounts for phase accumulation due to frequency offsets at the shunt. Results in phantom and healthy human participants reveal reliable quantification of flow rates using controlled flows and agreement with the flow simulation. EVD patients display reliable measures of flow rates. Shunt patient results demonstrate feasibility of the method and consistent flow rates for functional shunts. The results demonstrate the technique's applicability, accuracy, and potential for diagnosing and noninvasively monitoring hydrocephalus. Limitations of the current approach include a high sensitivity to motion and strict requirement of imaging slice prescription.

Interactions between foredune morphologies and vegetation: Exploring the occurrence of arbuscular mycorrhizal fungi

Vegetation is a key trait for understanding the foredune morphologies. However, the rhizosphere in coastal dunes imposes high levels of water and nutrient stress on plants. In these conditions, arbuscular mycorrhizal fungi (AMF) are prominent root symbionts that play a crucial role in improving to abiotic stress and promoting plant growth. On the south coast of the state of São Paulo, foredunes were studied for their floristic composition, relative frequency of AMF and grain size of rhizosphere. Foredune was classified regarding the morphology as terrace, ridge I, and ridge II. The terrace has a low height (<0.5 m) and is composed of native species canopies low (<0.2 m) and high (0.5–1.5 m) characterized by AMF colonization close to 60%. In contrast, ridge I showed wavy crests that were about 1 m high and ∼30 m wide, with a predominance of plant species with low canopy and 68% AMF colonization. The morphology ridge II reaches the greatest height (3 m), to the detriment of a smaller width (up to 15 m) and the plants present high canopy (>0.5 m) with close to 75% AMF. The increase of the relative frequency AMF from the terrace to ridges I and II may indicate that the increase of sand accumulation with continuous burial of roots is rather positive to plant growth. Yet, varied canopy heights of the plants species control the verticalization and horizontalization of the foredune. Low-canopy species, gradually slow down wind flow, causing spatialized deposition and widening. Conversely, species with highest canopies swiftly reduce wind flow due to the density of their aerial portion (leaves), resulting in deposition just below their structure fostering foredune vertical growth.

Optical Bubble Microflow Meter for Continuous Measurements in a Closed System

This paper describes the design, operation and test results of a simple microprocessor-based device for measuring slow liquid flows. The device uses a module of 30 digital optical sensors to track the movement of a single air bubble inserted into a tube of flowing liquid. During a measurement session, the air bubble remains within the sensor module at all times, allowing the instrument to take measurements for any length of time. The liquid whose flow rate is being measured moves only in the closed tube system, without contact with other components of the device. The test of the device itself was carried out using a tube with an inner diameter of less than 1 mm, where the device is capable of measuring flow rates on the order of microliters per minute. Tests of the device showed good agreement between the measured volumetric flow rate and the reference flow rates of the infusion pump over the entire measurement range. The advantages and limitations of the device are discussed, as well as the prospects for developing the method.

Establishment and verification of a nomogram that predicts the risk for coronary slow flow.

Coronary slow flow (CSF) has gained significance as a chronic coronary artery disease, but few studies have integrated both biological and anatomical factors for CSF assessment. This study aimed to develop and validate a simple-to-use nomogram for predicting CSF risk by combining biological and anatomical factors. In this retrospective case-control study, 1042 patients (614 CSF cases and 428 controls) were randomly assigned to the development and validation cohorts at a 7:3 ratio. Potential predictive factors were identified using least absolute shrinkage and selection operator regression and subsequently utilized in multivariate logistic regression to construct the nomogram. Validation of the nomogram was assessed by discrimination and calibration. N-terminal pro brain natriuretic peptide, high density lipoprotein cholesterol, hemoglobin, left anterior descending artery diameter, left circumflex artery diameter, and right coronary artery diameter were independent predictors of CSF. The model displayed high discrimination in the development and validation cohorts (C-index 0.771, 95% CI: 0.737-0.805 and 0.805, 95% CI: 0.757-0.853, respectively). The calibration curves for both cohorts showed close alignment between predicted and actual risk estimates, demonstrating improved model calibration. Decision curve analysis suggested high clinical utility for the predictive nomogram. The constructed nomogram accurately and individually predicts the risk of CSF for patients with suspected CSF and may be considered for use in clinical care.

Analysis of Risk Factors and Construction of a Predictive Model for Readmission in Patients with Coronary Slow Flow Phenomenon.

Coronary slow flow phenomenon (CSFP) is a phenomenon in which distal vascular perfusion is delayed on angiography, but coronary arteries are not significantly narrowed and there is no other organic cardiac disease. Patients with CSFP may be repeatedly readmitted to the hospital because of chest pain or other symptoms of precordial discomfort, and there is a risk of adverse events. In order to investigate the risk factors affecting the readmission of CSFP patients, a prediction model was constructed with the aim of identifying patients at risk of readmission at an early stage and providing a reference for further clinical intervention. In this study, we collected clinical data from 397 CSFP patients between June 2021 and January 2023 in Xinjiang Medical University Hospital. Telephone follow-up clarified whether the patients were readmitted to the hospital. A predictive model for readmission of CSFP patients was constructed using multifactorial logistic regression. Nomogram was used to visualize the model and bootstrap was used to internally validate the model. ROC, DCA and Calibration curve were plotted to evaluate the calibration and discriminative ability of the column line graphs, respectively. Calibration and resolution of the column line graphs, respectively. A total of 34 of 397 CSFP patients experienced readmission. Smoking history, creatine kinase isoenzyme-MB, total cholesterol, and left ventricular ejection fraction were the predictors of readmission in patients with CSFP. The area under the curve of the Nomogram model was 0.87, which indicated that the model had good predictive ability and differentiation, and the DCA and Calibration curves also indicated that the model had good consistency and was clinically useful. A readmission prediction model for patients with CSFP may facilitate early identification of patients at potential risk for readmission and timely interventional therapy to improve patient prognosis.

Radionuclide shuntography for cerebrospinal fluid shunt flow evaluation in adults.

Radionuclide shuntography (RS) performed using 99mTc-DTPA injected into the reservoir of CSF shunts enables evaluation of CSF flow for suspected shunt malfunctions. The goal of this study was to report the authors' institutional experience with RS and evaluate its utility and associated complications. The authors retrospectively reviewed all RS studies performed between November 2003 and June 2022. Patients with shunted hydrocephalus who were ≥ 18 years of age were included. Patients undergoing RS for evaluation of Ommaya reservoirs were excluded. Demographics, hydrocephalus etiology, presenting symptoms, study results, subsequent management, complications, and intraoperative diagnoses were recorded. Chi-square tests were reported for categorical variables and standard 2 × 2 contingency methods were used for sensitivity/specificity analysis. The authors identified 211 RS procedures performed in 142 patients. The mean age at procedure was 55.6 ± 20.9 years (mean ± SD). Normal pressure hydrocephalus was the most common hydrocephalus etiology (37.0%), followed by congenital malformations (26.1%) and idiopathic intracranial hypertension (15.6%). Successful radionuclide injection was achieved in 207 studies (98.1%). Shunt patency was confirmed in 63.8% of successful injections, whereas malfunction was demonstrated in 27.1% and abnormally slow flow was seen in 9.2%. RS studies demonstrating shunt malfunction were more likely to result in subsequent revisions than were studies showing patency (86.6% vs 2.9%; p < 0.0001). The overall sensitivity and specificity of RS for detecting shunt malfunction was 92.3% and 96.2%, respectively. The median follow-up time was 29 months, with 151 cases having ≥ 6 months of follow-up. There were no complications or infections attributable to RS in this cohort. RS is a useful and safe tool in the workup of shunt malfunction.

The Transition from Darcy to Nonlinear Flow in Heterogeneous Porous Media: I—Single-Phase Flow

Using extensive numerical simulation of the Navier–Stokes equations, we study the transition from the Darcy’s law for slow flow of fluids through a disordered porous medium to the nonlinear flow regime in which the effect of inertia cannot be neglected. The porous medium is represented by two-dimensional slices of a three-dimensional image of a sandstone. We study the problem over wide ranges of porosity and the Reynolds number, as well as two types of boundary conditions, and compute essential features of fluid flow, namely, the strength of the vorticity, the effective permeability of the pore space, the frictional drag, and the relationship between the macroscopic pressure gradient ∇P\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\varvec{\ abla }}P$$\\end{document} and the fluid velocity v. The results indicate that when the Reynolds number Re is low enough that the Darcy’s law holds, the magnitude ωz\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\omega _z$$\\end{document} of the vorticity is nearly zero. As Re increases, however, so also does ωz\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\omega _z$$\\end{document}, and its rise from nearly zero begins at the same Re at which the Darcy’s law breaks down. We also show that a nonlinear relation between the macroscopic pressure gradient and the fluid velocity v, given by, -∇P=(μ/Ke)v+βnρ|v|2v\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-{\\varvec{\ abla }}P=(\\mu /K_e)\ extbf{v}+\\beta _n\\rho |\ extbf{v}|^2\ extbf{v}$$\\end{document}, provides accurate representation of the numerical data, where μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu$$\\end{document} and ρ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\rho$$\\end{document} are the fluid’s viscosity and density, Ke\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K_e$$\\end{document} is the effective Darcy permeability in the linear regime, and βn\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta _n$$\\end{document} is a generalized nonlinear resistance. Theoretical justification for the relation is presented, and its predictions are also compared with those of the Forchheimer’s equation.

Slow flow in ectatic dilated coronary arteries as the cause of sudden cardiac arrest during diagnostic coronary angiography.

Slow flow in ectatic dilated coronary arteries as the cause of sudden cardiac arrest during diagnostic coronary angiography.

The MAPH Score Predicts Coronary Slow Flow. A Retrospective Case-Controlled Study.

The MAPH score is a new score that combines mean platelet volume (MPV), hematocrit, and total protein, which are markers of whole blood viscosity (WBV). We aimed to investigate the relationship between the MAPH score and the coronary slow flow phenomenon (CSF). A total of 201 patients were included in the study. 105 had CSF and 96 had normal coronary flow (NCF). Coronary flow was measured by the Thrombolysis in Myocardial Infarction frame count (TFC) method. The patients' MPV, age, hematocrit, and total protein were recorded. High (HSR) and low shear rates (LSR) were calculated, based on total protein and hematocrit values. Cut-off values for CSF were determined using the Youden's index, and the score was determined as 0 or 1 according to the cut-off values. The sum of these scores was the MAPH score. The mean age of the patients included in the study was 51.1±7.9 (n=201, 54.2 % male). Hyperlipidemia, DM, and HT rates of both groups were similar, but the mean age of the CSF group was higher (p=0.773; p=0.549; p=0.848; p &lt;0.001, respectively). Total protein, MPV, hematocrit, HSR and LSR were higher in the CSF group (p&lt; 0.001, for all values). Comparative receiver operating characteristic (ROC) curve analysis showed that the performance of the MAPH score in predicting CSF is better than the performance of these parameters separately. A new score, the MAPH score, may be used to identify the presence of CSF.

Using the Seraph® 100 Microbind® Affinity blood filter under slow flow conditions through 18 G and 16 G central lines.

The Seraph® 100 Microbind® Affinity blood filter (Seraph® 100) has been in use since 2019 for the treatment of fulminant or difficult to treat blood stream infections as an adjunct to pharmacotherapy. In 2020 the device received emergency use authorization by the US Food and Drug Administration for the treatment of critically ill COVID-19 patients with confirmed or imminent respiratory failure. Results of an international registry showed that the Seraph® 100 was operated under blood flow rates of 100-350 mL/min. As those conditions require a large bore central line, a dialysis catheter is currently considered indispensable to operate the Seraph® 100. The use of smaller catheter lumina has neither been evaluated in vitro nor in vivo. In vitro pressure data before and after the Seraph® 100 at various blood pump rates (prepump line 16 G, postpump line 18 G) with saline and human plasma were obtained. Further, anecdotal flow and pressure data of two patients treated with the Seraph® 100 for a COVID-19 infection are reported. At a pump speed of 50 mL/min pre-Seraph® pressure using saline was -70 [-70 to -60] mm Hg. In comparison, using plasma pre-Seraph® pressure was lower at -120 [-120 to -105] mm Hg; p < 0.001 (t-test). The post-Seraph® pressure at 50 mL/min using saline of 120 [110-130] mm Hg was not different from plasma at 130 [120-140] mm Hg, p = 0.152 (t-test). Blood flow rates of 50 mL/min did not lead to preAP levels below -250 mm Hg in the two clinical cases. Seraph® 100 blood flow rate of 50 mL/min may be achieved using low flow vascular access, allowing to treat a blood volume 72 L in 24 h.

The value of sonographic microvascular imaging in the diagnosis of lipedema.

Lipedema is a chronic disease marked by symmetric enlargement of painful nodular and fibrotic adipose tissue, predominantly affecting the limbs. Since there is no specific test or biomarker for this condition, years often pass before the diagnosis of lipedema is established for the first time, thereby causing psychosocial distress, including depression, eating disorders, and social isolation. Over the last few years several advanced Doppler-based technologies have been developed to visualize slow flow blood vessels and superficial microvascular architecture undetectable by traditional color Doppler flow imaging (CDFI). The aim of this study was to evaluate the superficial microvascular anatomy in lipedema patients compared to healthy controls and investigate the clinical significance of the Ultra Micro Angiography (UMA) technology in the diagnosis of lipedema. This new technique may contribute to reduce the diagnostic delay and, eventually, establish and guide treatment strategies toward a better therapeutic outcome in lipedema patients. 25 patients with lipedema and ten healthy controls with no history of lipedema were included in this study. All ultrasound examinations were performed on a novel high-performance ultrasound system (Resona R9/Mindray) using CDFI and the UMA technique. In all of the patients, Ultra Micro Angiography achieved the excellent visualization of microvascular structures, revealing that most lipedema patients showed grade 3 (n = 13) or grade 2 (n = 8) flow. UMA was superior to CDFI for depicting the microvascular structures. Here we show that UMA imaging characterizes the subcutaneous microvasculature with an unprecedented accuracy. The method has the advantage of being sensitive to small, slow-flowing vessels. This allows for the assessment of the course of vessels and vascular pathologies in great detail. Thus, UMA as a non-invasive diagnostic method can improve diagnostic accuracy in lipedema.