Blood Viscosity Research Articles

This study theoretically investigates blood rheology in arteries by modeling blood as an Oldroyd-B nanofluid with uniformly suspended Au, Cu, and Al2O3 nanoparticles. A fractional order framework is employed to capture memory and hereditary effects while preserving the invariance of governing equations. The influence of nanoparticle geometry is examined by considering spherical (isotropic), cylindrical (axial), and platelet-like (planar) shapes. Using integral transform techniques, a comparative analysis highlights how particle symmetry and system parameters affect flow behavior and heat transfer. Thermal effects are further analyzed as both a contributor to flow resistance and a source of symmetry breaking in conduction, with implications for optimizing nanofluid-based blood rheology in biomedical applications such as cryosurgery.

The current study's simulation made use of COMSOL Multiphysics' CFD. Blood was used as the basic fluid in this simulation. Blood was considered to be a laminar, unstable, and incompressible Newtonian fluid, and its Newtonian nature is tolerable at high shear rates. The behavior of blood flow was investigated to ascertain the effects of temperature, velocity, and pressure through vascular stenosis. Gold (Au) and silver (Ag) nanoparticles were the two types utilized in this investigation. The mass, momentum, and energy equations were solved using the CFD method. A fine element size mesh was made using COMSOL. The analysis's conclusions show that the artery's velocity fluctuates over constrained sections, falling both before and after the stenotic zone and being higher in a diseased location. The heat transfer feature's upper and lower boundary temperatures were selected to be 24.85°C and 27.35°C, respectively. The nanoparticles affected the density, specific heat, dynamic viscosity, and thermal conductivity of blood. The use of gold and silver nanoparticles prevented overheating since they both have high thermal conductivity, which is essential for quickly dispersing heat. Nusselt number variations were also calculated, and the results show that the curve decreases inside the stenosis. At t = 0.7 s and 1 s, recirculation occurs right after the stenosed area, and it is possible to infer that the streamlines behave abnormally. These discoveries will have a significant impact on the treatment of stenosed arteries.

Abstract Medicinal plasters have obvious value in promoting blood circulation and removing blood stasis, while their practical values are usually restricted by the skin barrier, resulting in lower local drug concentration and unsatisfactory therapeutic efficacy. Here, a novel non‐invasive microneedle patch coated with ferulic acid Chinese herbal plasters (FA@MNs) is presented for the treatment of localised bruising and swelling. The FA@MNs consists of a pyramid‐shaped blunt microneedle array core fabricated by poly(ethylene glycol) diacrylate (PEGDA) and traditional Chinese herbal plaster coating composed of ferulic acid and carbomer gel. This special design of microneedles can non‐invasively open the skin barrier, enabling more efficient drug delivery while avoiding potential skin damage. Besides, the traditional Chinese herbal plaster coated in microneedle arrays provides further adhesion to the skin surface. It has been demonstrated that the FA@MNs could effectively reduce blood viscosity and inflammatory response in rats while ensuring skin tissue integrity. These results certify that the novel non‐invasive microneedle patch has great potential in improving the effects of clinical medicinal plasters.

Key contributors to cell-free layer formation: An experimental investigation of hematocrit and shear rate gradient.

We measured the plasma levels of adrenomedullin in normotensive Wistar rats and spontaneously hypertensive rats (SHR) was investigated, and evaluated changes in its level under conditions of increased blood viscosity. Blood viscosity was increased by the method of isovolumic hemoconcentration (replacement of 10% of circulating blood with the same volume of packed erythrocytes of donor rats). The initial concentration of adrenomedullin in Wistar rats was 1912 ± 195 pg/ml, while in SHR it was 40% lower (p = 0.007). In Wistar rats, an increase in blood viscosity was accompanied by a decrease in the concentration of adrenomedullin by 1.8 times in comparison with the initial value, while in SHR it did not lead to significant changes in adrenomedullin level. The absence of changes in the plasma adrenomedullin concentration in SHR in response to blood viscosity elevation may indicate that the mechanotransduction mechanism is excluded from the regulation of vascular tone, which is probably one of the forms of endothelial dysfunction associated with its impaired sensitivity to shear stress changes.

Key Points Hematologic disorders in neonates are distinct from those in older children due to the ongoing nature of erythropoiesis and hemostasis, as well as the unique developmental physiology of newborns.The diagnosis of most hematologic disorders is based on reference ranges for the newborn and must account for gestational and postnatal age, as variation in normal hematologic values is higher in the neonatal period than at any other time of life.Neonatal anemia can be caused by blood loss, hemolysis, or decreased red cell production. Physiological anemia of the full-term newborn occurs between 6 and 12 weeks after birth and is not a pathological state. Anemia of prematurity is common in preterm infants, often requiring iron supplementation. Alloimmune hemolytic disorders, such as RhD and ABO incompatibility, are leading causes of hemolysis in neonates.Polycythemia in neonates, caused by increased erythropoiesis or erythrocyte transfusion, can result in serious complications from increased blood viscosity and impaired microcirculation.Hemostatic disorders in newborns, whether inherited or acquired, can be challenging to diagnose, as many coagulation protein concentrations are age dependent. Thrombocytopenia and thromboembolic disorders are common in sick neonates and are more often acquired than inherited.Vitamin K deficiency bleeding (ie, hemorrhagic disease of the newborn) is a significant concern in neonates, particularly in those who do not receive prophylactic vitamin K at birth. Bleeding manifestations in the classic form occur 2 to 7 days after birth in exclusively breastfed infants and are common without prophylaxis.Thrombocytopenia in neonates may result from immune-mediated mechanisms (eg, neonatal alloimmune thrombocytopenia [NAIT]), placing neonates at risk for severe bleeding, including intracranial hemorrhage.Neutropenia in neonates is often linked to maternal immune conditions and infections and, less commonly, genetic disorders of production. The risk of sepsis is significantly increased, and severe cases may require treatment with granulocyte colony-stimulating factor (G-CSF).

The high prevalence of inflammatory periodontal diseases (IPD) and the limited effectiveness of currently used treatments justify the relevance of developing new combination therapies that provide a comprehensive impact on both etiological factors and the main pathogenetic mechanisms underlying IPD Objective: To evaluate the effectiveness of a novel pharmacological composition in an experimental periodontitis model in laboratory animals. Materials and Methods: A comparative histological assessment was conducted to evaluate the effectiveness of the novel pharmacological composition (NPC) for local treatment of inflammatory periodontal diseases. The composition included silicon-zinc-organic glycerohydrogel, aminodihydrophthalazinedione sodium, pentoxifylline, and miramistin. The study was performed in Wistar rats with experimental periodontitis. In the main group (n=15), NPC was applied, while in the control group (n=15), standard pharmacotherapy was used. At days 5, 14, and 21 of treatment, animals were sacrificed for evaluation. Histological analysis of periodontal tissues was carried out, with assessment of the severity of inflammatory infiltrates and the condition of the microcirculatory bed. Results and Discussion: On day 5 after treatment, inflammatory infiltrates and uneven thickening of vascular walls were observed in both groups; however, in the main group, blood flow activity was present. By day 14, a reduction in inflammatory infiltrate density was seen in both groups. In the control group, vessels with thickened, sclerotic walls and reduced blood flow were noted, while the main group demonstrated signs of active neoangiogenesis and numerous functioning mature vessels. After 3 weeks, the control group still exhibited inflammatory infiltration and vessels with thickened, sclerotic walls and narrowed lumens, whereas in the main group, minimal infiltrates were observed, and the microcirculatory network appeared normal. Conclusions: The NPC demonstrated anti-inflammatory efficacy in the treatment of periodontitis in laboratory animals, promoting angiogenesis in periodontal tissues and improving blood rheology.

PurposePsoriasis with blood stasis syndrome (BSS) demonstrates aggravated skin lesions compared to psoriasis alone; however, the underlying mechanism remains unclear. This study aims to elucidate the pathological mechanisms of skin lesion exacerbation in psoriasis from the perspective of platelet activation.MethodsA psoriasis rat model was established by topical application of imiquimod (IMQ), while a psoriasis with BSS model was induced using ice–water baths and epinephrine injection. Skin lesions were assessed via hematoxylin and eosin (H&E) staining. Hemorheology was employed to evaluate BSS characteristics. Western blot (WB) was used to examine CD62P (P-selectin) and platelet-activating factor receptor (PAFR) expression to assess platelet activation. The platelet aggregation inhibitor clopidogrel was administered via oral gavage. The psoriasis area and severity index (PASI) was applied to evaluate clopidogrel’s therapeutic effect, and network pharmacology combined with quantitative reverse transcription PCR (RT–qPCR) was used to clarify its mechanism.ResultsHE staining indicated more severe skin lesions in psoriasis with BSS rats than in psoriasis rats (P<0.01). Hemorheological analysis revealed increased blood viscosity and microvascular proliferation in the psoriasis rats with BSS. WB showed significantly elevated expression of CD62P and PAFR in psoriasis with BSS rats (P<0.05). Clopidogrel reduced epidermal thickening, as assessed by the PASI score. Network pharmacology and RT–qPCR identified P2RY12 and GPIIb/IIIa as key targets through which clopidogrel ameliorates skin lesions in psoriasis with BSS.ConclusionPsoriasis with BSS rats exhibit more severe skin lesions than psoriasis rats, associated with enhanced platelet activation. Clopidogrel improved blood stasis and skin inflammation, confirming that platelet activation contributes critically to skin lesion worsening.

Aims: This study aimed to evaluate the utility of the MAPH score, a biomarker combining blood viscosity indicators such as mean platelet volume (MPV), total protein, and hematocrit, in differentiating acute ischemic stroke (AIS) from transient ischemic attack (TIA) and predicting major vessel occlusion in patients presenting to the emergency department with suspected stroke. Methods: A retrospective analysis was conducted on 226 patients presenting to the emergency department with focal neurological symptoms. Patients were categorized into AIS and TIA groups based on diffusion-weighted magnetic resonance imaging findings. Data collected included demographic characteristics, vital signs, laboratory parameters, and imaging results. MPV, age, hematocrit, and total protein levels were recorded. High-shear rate and low-shear rate were calculated from total protein and hematocrit values. ROC curve analysis was performed to evaluate diagnostic performance Results: The ROC analysis demonstrated the diagnostic accuracy of the MAPH score in differentiating AIS from TIA and predicting major vessel occlusion. Additionally, the score showed a significant correlation with NIHSS ≥20, indicating its association with stroke severity. Conclusion: The MAPH score is a simple and practical tool that aids in distinguishing AIS from TIA and predicting major vessel occlusion, thus improving stroke management in emergency settings.

Substantial research has been dedicated to new prognostication tools in aneurysmal subarachnoid hemorrhage (aSAH), with a recent focus on laboratory parameters. Our study investigates the predictive value of a new hematological index, the hematocrit-to-hemoglobin (Ht-to-Hb) ratio, for mortality and delayed cerebral ischemia (DCI). This is a retrospective, single-center, observational study on 78 adult critically ill patients with aSAH. We collected data from the electronic and written records, including demographic and clinical data, therapeutic measures, and intensive care unit and hospital length of stay. The primary outcome was in-hospital mortality, whereas the secondary outcome was DCI development. After descriptive analysis was performed, the Ht-to-Hb ratio was tested as a predictor for the primary and secondary outcomes. Firstly, we conducted a receiver operating characteristic analysis, and cutoff values were identified using the Youden index. Further, in-hospital mortality and DCI probability were evaluated using the log rank test. Cox proportional hazards regression was conducted to test the independent predictive value of the Ht-to-Hb ratio for the aforementioned outcomes. Mortality during hospitalization was 25.54%, whereas DCI frequency was 42.3%. The Ht-to-Hb ratio had areas under the receiver operating characteristic curve for death prediction and DCI of 0.85 and 0.734, respectively. Values greater than the cutoff value for mortality, 3.069, were independently associated with the primary outcome in the multivariable analysis (hazard ratio [HR] 4.64, 95% confidence interval [CI] 1.08-19.98, p = 0.039). For DCI, the cutoff value identified was 3.007. Ht-to-Hb ratios > 3.007 were an independent risk factor for DCI in the multivariable analysis (HR 3.86, 95% CI 1.43-10.4, p = 0.008). The present study proposes a new prognostic index for mortality and DCI in aSAH: the Ht-to-Hb ratio. This marker could act as a surrogate for blood viscosity, uncovering the importance of blood rheology in aSAH pathogenesis.

Disclosure: M.J. Barnett: None. J.R. Lam: None. C. Casipit: None. A. Rivadeneira: None.Introduction: Hypothyroidism is associated with decreased metabolism, affecting multiple bodily systems. Hypothyroidism appears to present a heightened risk for thrombosis through impairment of vascular flow, altered blood viscosity and disruption of fibrinolysis. The comparative risk for thrombosis in hypothyroidism over thyrotoxicosis, however, has not been explored. Objectives: The primary objectives of this study are to assess the risk for thromboses (deep venous, pulmonary emboli, central nervous system, and arterial) in patients with hypothyroidism compared to hyperthyroidism, as well as compare the survival probabilities following such events. Secondary objectives are to analyze laboratory values which may provide insight into the differing mechanisms for the heightened risk for thromboses. Methods: This study was performed using TriNetX Global Network, providing anonymized data from 145 healthcare organizations, and analyzed retrospectively. Participants were categorized into either hyperthyroidism (Cohort 1) (with > 2 instances, n = 539, 907) or hypothyroidism (Cohort 2) (with > 2 instances, n = 3,416,216). Balancing was achieved with propensity score matching, with n = 484, 944 per cohort. Participants were balanced for age (current and at index), gender, ethnicity, race, diagnosis of diabetes, hypertension, overweight/obesity, history of ischemic heart disease and neoplasia. Outcomes analyzed included pulmonary emboli, deep venous thromboses (DVT), intracranial/intraspinal thrombophlebitis, and arterial thromboses. Risk differences, risk ratios, odds ratios and Kaplan-Meier survival analyses were calculated within a 10-year observation window post-index event. Results: Following matching, thrombotic risk was lower in Cohort 1 than in Cohort 2 across multiple outcomes, including pulmonary emboli (1.4% versus 1.7%, OR 0.789, 95% CI: 0.764-0.816, p < 0.0001), lower extremity DVT (1.2% versus 1.6%, OR 0.763, 95% CI: 0.737-0.789, p < 0.0001), upper extremity DVT (0.104% versus 0.138%, OR 0.752, 95% CI: 0.67-0.845, p < 0.0001), and combined thromboses (venous or arterial) (2.8% versus 3.5%, OR 0.781, 95% CI: 0.763-0.799, p < 0.0001). There was no significant difference between intracranial and intraspinal thrombophlebitis (p = 0.078). Concerning secondary objectives, there was no significant difference in mean Fibrin D-dimer levels (p = 0.658) or von-Willebrand Factor (p = 0.962), however, mean fibrinogen levels were significantly lower in Cohort 1 (383.7 mg/dL versus 391.5 mg/dL, p < 0.0001). Conclusion: This study suggests hypothyroidism is associated with a higher risk for thrombosis, both venous and arterial, compared to hyperthyroidism, underscoring the importance of considering thrombotic complications in thyroid dysfunction. Further studies are needed to concur with these findings and provide insight into further management.Presentation: Saturday, July 12, 2025

Disclosure: A. Al-Thunaibat: None. L.L. Ponce Rosas: None. K. Sanu: None. A. Abualnil: None. J.S. Martins Torrontegui: None. C. Penaherrera: None.Introduction: The use of testosterone has become increasingly prevalent in recent years, both through medical prescriptions and non-medical, unauthorized channels. While testosterone is primarily prescribed for the management of hypogonadism, it is also widely misused by athletes and bodybuilders to enhance muscle mass and physical performance due to its anabolic effects. Herein, we presented a case of PE and DVT secondary to testosterone use in a patient with no other risk factors for venous thromboembolism (VTE). Case Presentation: A 45-year-old male with a medical history of HTN, primary hypogonadism, polycythemia secondary to testosterone supplement, asthma, and OSA on CPAP presented to the ED with progressive shortness of breath. He had been on testosterone replacement therapy (TRT) for over seven years. Due to polycythemia, he was advised to undergo therapeutic phlebotomy twice monthly but had been non-compliant for the past month. On presentation, laboratory results showed Hgb 17.8 g/dL, HCT 55%, RBC 6.6 million/μL, WBC 20,000/μL, and troponin 70 ng/L. ABG values 7.40/27/53/17, and total testosterone level was 1004 ng/dL. CT chest with IV contrast revealed massive bilateral pulmonary emboli with right heart strain. Lower extremity doppler ultrasound demonstrated a DVT in the right posterior tibial vein. The patient underwent catheter-directed thrombolysis via EKOS procedure and was subsequently transitioned to a DOAC. Given the diagnosis of VTE, TRT was discontinued permanently. Discussion: Testosterone has well-documented erythropoietic effects, which can contribute to erythrocytosis (HCT > 54%) and increased blood viscosity, thereby raising the risk of VTE. According to the Endocrine Society guidelines, TRT should be withheld if HCT exceeds 54%, and to be resumed only after HCT returns to the normal range, typically at a lower dose. Additionally, therapeutic phlebotomy—in which one unit of blood (500 mL) is removed at regular intervals—is an effective strategy for managing testosterone-induced erythrocytosis. Per the American Urological Association guidelines, total testosterone and CBC should be measured every 6-12 months during therapy. Conclusion: Erythrocytosis is a well-recognized adverse effect of TRT, requiring regular monitoring of CBC and serum testosterone levels. If HCT exceeds 54%, the TRT dose should be adjusted or temporarily discontinued, and therapeutic phlebotomy may be considered to reduce the risk of VTE.Presentation: Sunday, July 13, 2025

Effectiveness of 10.6-μm laser therapy for diabetic peripheral neuropathy: a double-blind, randomized controlled trial.

Living donor hepatectomy carries a risk of bleeding, and allogeneic transfusion may cause adverse effects. Autologous blood preparation is therefore considered a safer strategy. While preoperative autologous donation (PAD) is widely used, acute normovolemic hemodilution (ANH) may overcome its limitations and offer a practical alternative. However, evidence supporting ANH in donor surgery remains limited. This study compared the clinical utility of ANH and PAD in living donor hepatectomy. We retrospectively analyzed 60 consecutive cases of living donor right hepatectomy performed between 2017 and 2025. Among them, 58 donors who received either PAD or ANH were compared using 1:2 propensity score matching. Perioperative laboratory values, surgical outcomes, any allogeneic transfusion, and postoperative complications were evaluated. No unexpected intraoperative adverse events or allogeneic transfusions occurred. All ANH donors received autologous reinfusion, compared with only 6.5% of PAD donors. After matching, 27 donors (18 PAD, 9 ANH) were analyzed. Whole blood viscosity was higher in the ANH group. Weight-adjusted intraoperative bleeding was lower (2.6 vs. 4.6 mL/kg, p = .024; q = 0.106) and operative time was shorter (321 vs. 390 min, p = .007; q = 0.077) in the ANH group. Postoperative complication rates were comparable. Area under the curve analysis indicated better preservation of total protein (p = .038) and prothrombin time-international normalized ratio (p = .010) across the perioperative period in the ANH group. ANH maintained transfusion avoidance and donor safety comparable to PAD while improving operative efficiency, supporting ANH as a safe, effective alternative in living donor right hepatectomy.

Molecular communication (MC) has emerged as a promising paradigm for nanoscale information exchange in Internet of Bio-Nano Things (IoBNT) environments, offering intrinsic biocompatibility and potential for real-time in vivo monitoring. This study proposes a cascaded MC channel framework for vascular stenosis detection, which integrates non-Newtonian blood rheology, bell-shaped constriction geometry, and adsorption–desorption dynamics. Path delay and path loss are introduced as quantitative metrics to characterize how structural narrowing and molecular interactions jointly affect signal propagation. On this basis, a peak response time-based delay inversion method is developed to estimate both the location and severity of stenosis. COMSOL 6.2 simulations demonstrate high spatial resolution and resilience to measurement noise across diverse vascular configurations. By linking nanoscale transport dynamics with system-level detection, the approach establishes a tractable pathway for the early identification of vascular anomalies. Beyond theoretical modeling, the framework underscores the translational potential of MC-based diagnostics. It provides a foundation for non-invasive vascular health monitoring in IoT-enabled biomedical systems with direct relevance to continuous screening and preventive cardiovascular care. Future in vitro and in vivo studies will be essential to validate feasibility and support integration with implantable or wearable biosensing devices, enabling real-time, personalized health management.

Breaking the vicious cycle in sickle cell disease: Redox stress impairs red blood cell rheology and promotes lung vasocongestion.

A new theoretical model of apparent blood viscosity with the Fåhræus-Lindqvist effect using informational entropy-based approach.

Predicting red blood cell transport and capillary hemodynamics in angiogenic and tumor vascular networks in silico.

Targeting thrombin to screen safe thrombin inhibitors from natural plants and animals is a critical direction in anticoagulant drug development. This study aimed to screen thrombin inhibitors from the nonbloodsucking leech Whitmania pigra (WP) and elucidate the mechanism of anticoagulation through a "computation-guided experimentation" strategy. A peptide library was constructed from WP hydrolysates, and virtual screening was performed using molecular docking and dynamics simulations. A novel thrombin-targeting anticoagulant peptide PEPWP (LRELEDALEQER) was screened out from the peptide library and validated through invitro/in vivo experiments. PEPWP significantly prolonged thrombin time (TT) and prothrombin time (PT) in a dose-dependent manner invitro, indicating its role in the common and extrinsic coagulation pathways. Surface plasmon resonance (SPR) analysis then confirmed strong thrombin binding (Kd = 7.242 × 10-6 mol/L). Furthermore, PEPWP prolonged TT while reducing blood viscosity in acute blood stasis rats. Finally, structural analysis revealed that PEPWP bound to Exosite II of thrombin. Arg233 and Arg101 were the key residues for the binding. In conclusion, PEPWP exhibited good anticoagulant activity and significant application potential.

Comparative assessment of classical and fractional Casson models for hemodynamic flow in inclined vessels.