Background: Vitamin B 12 deficiency has been implicated in endothelial dysfunction and cardiovascular disease via hyperhomocysteinemia. Coronary tortuosity (CorT) is a common coronary angiography finding. The etiology, clinical implication and long term prognosis are still not well clarified. This study was conducted with the aim to evaluate the relationship between CorT and vitamin B12. Subjects and Method: The medical records of consecutive patients, who underwent coronary angiography, were retrospectively reviewed. The study group consisted of 1624 patients. Taking into consideration the inclusion criteria, 212 patients with CorT and 210 patients with normal coronary angiographies (control group) were included in the study. Vitamin B12, other biochemical parameters, clinical and echocardiographic parameters, and CorT score were evaluated in all patients. CorT is defined as fixed 3 bends during both systole and diastole, with each bend ≥45 °. Results: Patients with CorT had higher prevalence of older, female gender, hypertension, current smoking. Vitamin B12 was significantly decreased in patient with CorT (134.7±47.8 vs 239.6±53.8 p<0.001). On multivariate analysis age, female gender, hypertension, diabetes mellitus and vitamin B12 were independent predictors for CorT (OR 1.56; 95% CI: 1.247–1.962; p < 0.001, OR 1.628; 95% CI: 1.376-2.048; p<0.001, OR 1.865; 95% CI: 1.387-2.695; p<0.001, OR 1.362; 95% CI: 1.184-1.726; p<0.001, OR 1.862; 95% CI: 1.486-2.674; p<0.001, respectively). Conclusion: In our study, we have founded a significant relationship between vitamin B12 deficiency and CorT.

Physical reason for the small scale tortuosity observed in sparks and lightning channels is unknown at present. In this paper it is suggested that the small scale tortuosity of the discharge channels is caused by the natural tendency for subsequent leader streamer bursts to avoid each other but at the same time to align as much as possible along the direction of the background electric field. This process will give rise to a discharge channel that re-orients in space during each streamer burst creating the small scale tortuosity.

In this work, the transport equations of ionic species in concrete are studied. First, the equations at the porescale are considered, which are then averaged over a representative elementary volume. The so obtained transport equations at the macroscopic scale are thoroughly examined and each term is interpreted. Furthermore, it is shown that the tortuosity-connectivity does not slow the average speed of the ionic species down. The transport equations in the representative elementary volume are then compared with the equations obtained in an equivalent pore. Lastly, comparing Darcy’s law and the Hagen-Poiseuille equation in a cylindrical equivalent pore, the tortuosity-connectivity parameter is obtained for four dierent concretes. The proposed model provides very good results when compared with the experimentally obtained chloride profiles for two additional concretes.

Background: Coronary tortuosity is a common angiographic finding. Scarce data is available on clinical profile of patients with coronary tortuosity (CT) and its relation with coronary artery disease (CAD). Method: A total 224 patients undergoing angiography for suspected CAD were included in the study. CT was defined by the presence of ≥3 consecutive bends of > 45 degree measured at end-diastole in an epicardial artery ≥2 mm in diameter. CT was present in 45(20.08%) patients in the study and another 45 patients without CT was randomly selected as control (NCT group). Clinical profile of CT and NCT group was compared. Results: Incidence of CT was significantly higher in females (p=0.000) and hypertensives (p=0.001) patients. CT was most commonly seen in Left circumflex coronary artery. Incidence of CAD was significantly lower in CT group as compare to NCT group (0.02). Risk factors for CAD was associated with reduced incidence of CT. Majority (88.46%) patient with CT without CAD presented with chronic stable angina out of which (65.21%) had an objective evidence of myocardial ischemia. Conclusion: CT is more commonly seen females and hypertensive patients. It has negative correlation with CAD. Risk factors of CAD do not predict CT. CT itself can lead to myocardial ischemia.

We present our experience with the implantation of flow diverter stents (FDSs) for the management of intern carotid artery (ICA) dissections in tortuous tonsillar loop segments. 16 patients (10 women, 62.5%; mean age 39±8 years; median baseline NIHSS 13; median ASPECTS 8.5) with acute ischemic stroke due to ICA dissection in a tortuous tonsillar loop segment, with/without large intracranial vessel thrombotic occlusion, from 6/2015−2/2022 were included in this retrospective study under a waiver of informed consent. An FDS device was deployed from the petrous ICA toward the upper cervical ICA, completely covering the tonsillar loop. Stentriever-assisted thrombectomy was performed when indicated. A dual antiplatelet regimen was used during and after the procedure. Thrombocyte inhibition levels were evaluated before, during, and after the intervention. The ICA occlusion/near occlusion was successfully recanalized in all 16 patients with postangioplasty residual stenosis of 34±14% (range 0−50%). Stent-assisted embolectomy was performed in 15/16 patients (93.7%), achieving revascularization (TICI 2b−3) in all. There were no procedural complications and no intraprocedural embolic events; one asymptomatic petechial hemorrhage was detected. At 3-month follow-up, mRS 0−2 was seen in all patients. This report provides pilot data for a subsequent study on the use of flow diverter stents for ischemic cerebrovascular conditions. Our encouraging preliminary results await confirmation from further experience and prospective randomized studies.

The mixing of terrestrial groundwater and seawater creates dynamic reaction zones in intertidal areas, where land-derived Fe(II) is oxidized to Fe(III) and then precipitates as Fe hydroxides at groundwater-seawater interface. These hydrogeochemical processes contribute to the formation of iron curtains beneath soil surface, which in turn influences the evolution of coastal aquifers. This paper provides a comprehensive review of physical and geochemical processes at field scale in coastal areas, explores the impact of mineral precipitation on pore structure at pore scale, and synthesizes reactive transport modeling (RTM) approaches for illustrating continuum-scale soil physio-chemical parameters during the evolution of porous media. Upon this review, knowledge gaps and research needs are identified. Additionally, challenges and opportunities are presented. Therefore, the incorporation of observational data into a comprehensive physico-mathematical model becomes imperative for capturing the pore-scale processes in porous media and their influence on groundwater flow and solute transport at large scales. Furthermore, a synergistic approach integrating pore-scale modeling and non-invasive imaging can provide detailed insights into intricate fluid-pore-solid interactions for future studies, as well as facilitate the development of regional engineering-scale models and physio-chemical coupled models with diverse applications in submarine science and engineering.

Abstract: This paper outlines the methodology and results for a two species finite volume scalar computational drug transport model developed for simulating the mass transport of Poly(lactic-co-glycolic acid (PLGA) ) from a half-embedded single strut implanted in a coronary arterial vessel wall. The mathematical drug transport model incorporates the convection-diffusion equation in scalar form (dimensionless) with a two species (free-drug and bound-drug) mass transport setup including reversible equilibrium reaction source terms for the free and bound-drug states to account for the pharmaco-kinetic reactions in the arterial wall. The relative reaction rates of the added source terms control the interconversion of drug between the free and bound-drug states. The model is solved by a 2-D finite-volume method for discretizing and solving the free and bound drug transport equations with anisotropic vascular drug diffusivities. This model is an improvement over our previously developed model using the finite-difference method. A dimensionless characteristic scaling pre-analysis was conducted a priori to evaluate the significance of implementing the reaction source terms in the transport equations. This paper reports the findings of an investigation of the interstitial flow profile into the arterial wall and the free and bound drug diffusion profiles with a parametric study of varying polymer drug concentration (low and high), tortuosity, porosity, and Peclet and DamKöhler numbers over the course of 400 hours (16.67 days). The results also reveal how a single species drug delivery model that neglects both a reversible binding reaction source term and the porosity and tortuosity of the arterial wall cannot accurately predict the distribution of both the free and bound drug.