Vessel Diameter Research Articles

Root topological order drives variation of fine root vessel traits and hydraulic strategies in tropical trees.

Vessel traits contribute to plant water transport from roots to leaves and thereby influence how plants respond to soil water availability, but the sources of variation in fine root anatomical traits remain poorly understood. Here, we explore the variations of fine root vessel traits along topological orders within and across tropical tree species. Anatomical traits were measured along five root topological orders in 80 individual trees of 20 species from a tropical forest in southwestern China. We found large variations for most root anatomical traits across topological orders, and strong co-variations between vessel traits. Within species, theoretical specific xylem hydraulic conductivity (Kth) increased with topological order due to increased mean vessel diameter, size heterogeneity, and decreased vessel density. Across species, Kth was associated with vessel fraction in low-order roots and correlated with mean vessel diameter and vessel density in high-order roots, suggesting a shift in relative anatomical contributors to Kth from the second- to fifth-order roots. We found no clear relationship between Kth and stele: root diameter ratios. Our study shows strong variations in root vessel traits across topological orders and species, and highlights shifts in the anatomical underpinnings by varying vessel-related anatomical structures for an optimized water supply.

Implications of leaf micro-morphological and structural parameters in the regulation of transpiration in durum wheat cultivars under semi-arid conditions of Algeria

Abstract. In Algeria, drought is a major abiotic constraint responsible for the low productivity of durum wheat. This study aims to identify some mechanisms involved in water deficit adaptation and tolerance. The tolerance mechanism is conditioned by different characteristics governing the regulation of transpiration in its two forms from the leaf. This study analyzed 23 durum wheat genotypes under two water regimes: irrigated and rain-fed.The results of this study showed that the variation of the transpiration level is strongly conditioned by the leaf micro morphological and structural parameters represented by a reduction in woody vessels diameter, the compaction of the mesophyll. Indeed, the reduction of transpiration is due to the decrease in stomata density on the lower side of the leaf. This reduction resulted in a reduction of coating cells size which induces the approach of the stomata fills.

Quantitative assessment of carotid ultrasound diameter measurements in the operating room: a comparable analysis of long-axis versus rotated and tilted orientation

Objective. Carotid ultrasound (US) has been studied as a non-invasive alternative for hemodynamic monitoring. A long-axis (LA) view is traditionally employed but is difficult to maintain and operator experience may impact the diameter estimates, making it unsuitable for monitoring. Preliminary results show that a new, i.e. rotated and tilted (RT) view is more robust to motion and less operator-dependent. This study aimed to quantitatively assess common carotid diameter estimates obtained in a clinical setting from an RT view and compare those to corresponding estimates obtained using other views. Approach. Carotid US measurements were performed in 30 adult cardiac-surgery patients (26 males, 4 females) with short-axis (SA), LA, and RT probe orientations, the first being used as a reference for measuring the true vessel diameter. Per 30 s acquisition, the median and spread in diameter values were computed, the latter representing a measure of robustness, and were statistically compared between views. Main results. The median (IQR) over all the patients of the median diameter per 30 s acquisition was 7.15 (1.15) mm for the SA view, 7.03 (1.51) mm for the LA view, and 6.99 (1.72) mm for the RT view. The median spread in diameter values was 0.18 mm for the SA view, 0.16 mm for the LA view, and 0.18 mm for the RT view. There were no statistically significant differences between views in the median diameter values (p = 0.088) or spread (p = 0.122). Significance. The RT view results in comparable and equally robust median carotid diameter values compared to the reference. These findings open the path for future studies investigating the use of the RT view in new applications, such as in wearable ultrasound devices.

Balón liberador de sirolimus en el tratamiento del síndrome coronario agudo y crónico: el estudio PEACE, un subanálisis del registro EASTBOURNE

Introduction and objectivesThe PEACE study (Performance of a sirolimus-eluting balloon strategy in acute and chronic coronary syndromes) investigated for the first time whether a sirolimus-coated balloon (SCB) (Magic Touch, Concept Medical, India) is associated with different outcomes depending on whether it is used in acute coronary syndromes (ACS) or chronic coronary syndromes (CCS). MethodsThis was a post-hoc analysis from the all-comers EASTBOURNE Registry (NCT03085823). Out of 2083 patients enrolled, an SCB was used to treat 968 (46.5%) ACS and 1115 (53.5%) CCS patients. The primary endpoint was target lesion revascularization at 12 months, while secondary endpoints were angiographic success and major adverse cardiovascular events. ResultsBaseline demographics, mean reference vessel diameter and mean lesion length were comparable between ACS and CCS. Predilatation was more commonly performed in ACS (P=.007). SCB was inflated at a standard pressure in both groups with a slight trend toward longer inflation time in ACS. Angiographic success was high in both groups (ACS 97.4% vs CCS 97.7%, P=.820) with limited bailout stenting. Similarly, at 12 months the cumulative incidence of target lesion revascularization (ACS 6.6% vs CCS 5.2%, P=.258) was comparable between ACS and CCS. Conversely, a higher rate of major adverse cardiovascular events in acute presenters was mainly driven by myocardial infarction recurrencies (ACS 10.4% vs CCS 8.3%, P=.009). In-stent restenosis showed a higher proportion of target lesion revascularization and major adverse cardiovascular events than de novo lesions, independently of the type of presentation at the index procedure. ConclusionsThis SCB shows good performance in terms of acute and 1-year outcomes independently of the clinical presentation.

Comparison of pipeline embolization device and tubridge flow diverter for posterior circulation aneurysms: A multicentre propensity score matched study

Rationale and objectivesThe off-label use of flow diverters (FDs) has broadened to include treating aneurysms in posterior circulation (PC). A novel flow diverter, the Tubridge flow diverter (TFD), has been created in China specifically for treating PC aneurysms. However, studies comparing between pipeline embolization device (PED) and TFD are rare. Thus, our study aimed to explore the effectiveness of PED and TFD in the treatment of PC aneurysms using a propensity score matched cohort design. MethodsRetrospective data collection was conducted on patients who underwent treatment with either PED or TFD over the period from 2015 through 2020. Propensity score matching (PSM) was employed to calibrate for patient age; history of ischemic stroke; aneurysm size; morphology; location and neck; number of FDs; parent vessel diameter; and the employment of assisted coiling and balloon techniques. Data on previously ruptured aneurysms was not included in the analysis. A comparison was conducted between the two devices to assess perioperative complications, aneurysm occlusion rates, and functional outcomes. ResultsA total of 252 PC aneurysms were treated in 248 patients. Clinical and imaging follow-ups were lost in 26 and 47 patients, respectively. Major perioperative complications occurred in 7.5% of the cases, with favorable clinical outcomes in 91.0% and complete occlusion in 79.1%. Eighty-two (32.5%) aneurysms were treated with TFD, while 170 (67.5%) aneurysms were treated with PED. PSM was used to account for these significant variations, producing 82 matched pairs of unruptured aneurysms treated with PED or TFD. In terms of functional and angiographic outcomes, no significant differences were found between PED and TFD (functional outcome, p = 0.594 and angiographic outcome, p = 0.415). However, more perioperative major complications were found in patients treated with TFD (p = 0.005) compared with those receiving PED. ConclusionThe comparative study of PED and TFD in the treatment of PC aneurysms resulted in positive clinical results and sustained occlusion rates, with acceptable perioperative complications. However, higher quality studies are needed to enhance our understanding of the use of FDs for treating of PC aneurysms.

An evaluation of Astragali Radix with different growth patterns and years, based on a new multidimensional comparison method.

With the depletion of wild Astragali Radix (WA) resources, imitated-wild Astragali Radix (IWA) and cultivated Astragali Radix (CA) have become the main products of Astragali Radix. However, the quality differences of three growth patterns (WA, IWA, CA) and different growth years of Astragali Radix have not been fully characterized, leading to a lack of necessary scientific evidence for their use as substitutes for WA. We innovatively proposed a multidimensional evaluation method that encompassed traits, microstructure, cell wall components, saccharides, and pharmacodynamic compounds, to comprehensively explain the quality variances among different growth patterns and years of Astragali Radix. Our study showed that the quality of IWA and WA was comparatively similar, including evaluation indicators such as apparent color, sectional structure and odor, thickness of phellem, diameter and number of vessels, morphology of phloem and xylem, and the levels and ratios of cellulose, hemicellulose, lignin, sucrose, starch, water-soluble polysaccharides, total-saponins. However, the content of sucrose, starch and sorbose in CA was significantly higher than WA, and the diameter and number of vessels, total-flavonoids content were lower than WA, indicating significant quality differences between CA and WA. Hence, we suggest that IWA should be used as a substitute for WA instead of CA. As for the planting years of IWA, our results indicated that IWA aged 1-32 years could be divided into three stages according to their quality change: rapid growth period (1-5 years), stable growth period (6-20 years), and elderly growth period (25-32 years). Among these, 6-20 years old IWA exhibited consistent multidimensional comparative results, showcasing elevated levels of key active components such as water-soluble polysaccharides, flavonoids, and saponins. Considering both the quality and cultivation expenses of IWA, we recommend a cultivation duration of 6-8 years for growers. In conclusion, we established a novel multidimensional evaluation method to systematically characterize the quality of Astragali Radix, and provided a new scientific perspective for the artificial cultivation and quality assurance of Astragali Radix.

Qualitative and quantitative anatomical characteristics and radial variation of major cell components in Paulownia tomentosa wood grown in Korea

Qualitative and quantitative anatomical characteristics and radial variations of the major cell components in Paulownia tomentosa wood were examined using optical microscopy and X-ray diffraction to aid in wood identification and as quality indices. The vessel arrangement on the transverse surface was either ring-porous or semi-ring-porous. Most vessels had solitary pores, while some vessels had multiple radial pores. The axial parenchyma was generally confluent and partially of aliform type. Tyloses with high frequency in the vessel lumen and multiseriate rays (2 to 5 cells) were typical. The vessel diameter of earlywood and latewood was approximately 240 and 107 μm, respectively, with a range of 165 to 289 μm in earlywood and 55 to 149 μm in latewood. Ray height and fiber length were approximately 178 and 740 μm, respectively. The vessel diameter in both earlywood and latewood and the fiber length increased gradually with an increasing number of growth rings. Ray height was constant from the pith to the middle section and decreased toward the bark. The anatomical characteristics and radial variation of major components of P. tomentosa can be used as wood identification keys and quality indices.

Retinal vessel diameters in intermediate age-related macular degeneration using en face optical coherence tomography

ABSTRACT Clinical relevance Clinical assessment of age-related macular degeneration (AMD) relies on biomarkers that do not necessarily reflect the contributions of vascular dysfunction. Validation of clinically accessible methods of measuring retinal vascular integrity could provide a more holistic understanding of AMD-related changes to facilitate appropriate care. Background There is conflicting evidence if retinal vessel calibre is significantly altered in the early stages of AMD. This study examined the outer and inner diameters of first order retinal vessels in intermediate AMD eyes using en face optical coherence tomography (OCT). Methods Retinal en face (6 × 6 mm) OCT images were examined in a single eye of participants with intermediate AMD (n = 46) versus normal macula (n = 43) for arterioles (all identifiable) and venules (40/46 and 39/43 identifiable). All participants were aged ≥50 years without diabetes mellitus, hypertension, or other systemic vascular disease. Results Intra- and inter-grader agreement was good-to-excellent for all en face OCT measurements of arteriole and venule diameters (intraclass correlation coefficient = 0.87 to 0.99). Arteriolar outer diameters (82.3 ± 19.8 µm vs 73.8 ± 16.1 µm; p < 0.05) and inner diameters (35.1 ± 8.4 µm vs 31.5 ± 8.1 µm; p < 0.05) were significantly greater in AMD eyes compared to normal eyes. Venular inner diameter was significantly greater (43.1 ± 9.5 µm vs 39.2 ± 10.1 µm; p < 0.05), but outer diameter remained unchanged (p = 0.17) in AMD eyes compared to normal eyes. Conclusion Arteriolar dilation and altered venular inner diameter were observed in intermediate AMD eyes. These results support further investigation of vascular contributions to AMD in the early stages of disease, possibly using the en face OCT imaging modality.

Repeat drug-coated balloon angioplasty for femoropopliteal lesions: 12-month results from a retrospective observational study

BackgroundThe clinical implications of restenosis after drug-coated balloon (DCB) treatment remain unclear. We compared the clinical outcomes between DCB angioplasty for restenosis and de novo femoropopliteal artery lesions. This single-center retrospective study included 571 patients (737 limbs) who underwent either repeat (54 patients, 64 limbs) or de novo DCB (517 patients, 673 limbs) without bailout stenting. After propensity score matching, 49 matched pairs were analyzed. The primary endpoint was the 1-year primary patency, with secondary endpoints including the freedom from target lesion revascularization (TLR), major adverse limb events (MALE), and early restenosis. Predictors of restenosis were identified using multivariable Cox regression analysis.ResultsThe repeat-DCB group displayed significantly lower rates of 1-year primary patency and freedom from TLR compared to those of the de novo-DCB group (50.1% vs. 77.4%, p = 0.029 and 54.9% vs. 83.6%, p = 0.0.44, respectively). No significant differences were observed in early restenosis or MALE (10.7% vs. 5.9%, p = 0.455 and 48.3% vs. 73.4%, p = 0.055, respectively). Restenosis after DCB angioplasty was associated with repeat DCB (hazard ratio [HR], 5.13; 95% confidence interval [CI], 1.43–18.4; p = 0.012) and small vessel size of < 4.5 mm (HR, 6.25; 95% CI, 1.17–33.4; p = 0.032). Furthermore, restenosis after repeat DCB angioplasty was associated with the Peripheral Artery Calcification Scoring System (PACSS) grade 4 (HR, 4.20; 95% CI, 1.08–16.3; p = 0.038), small vessel size of < 4.5 mm (HR, 9.44; 95% CI, 1.21–73.7; p = 0.032), and intravascular ultrasound (IVUS) use (HR, 0.05; 95% CI, 0.01–0.44; p = 0.007).ConclusionsThe 1-year primary patency rate following repeat DCB angioplasty for femoropopliteal lesions was notably lower than that of DCB treatment for de novo lesions. Repeat DCB strategy was associated with an increased risk of patency loss. Regarding repeat restenosis after DCB treatments, PACSS grade 4 calcification and small vessel diameter of < 4.5 mm were associated with an increased risk of restenosis, whereas IVUS use correlated with a decreased risk of restenosis.

Evaluation of Choroidal Structure in Type 1 Macular Neovascularization Using Different Optical Coherence Tomography Analyses: Scale Bar and Binarization.

Macular neovascularization (MNV) has been evaluated by optical coherence tomography (OCT) imaging using various approaches. However, few studies have examined their differences. This study analyzed type 1 MNV with a combination of two approaches: scale bar and binarization. We enrolled 84 patients with untreated type 1 MNV. We measured choroidal parameters using a scale bar and defined the ratios of superficial choroidal thickness to choroidal vessel diameter (SV ratios). We also used binarization and calculated the ratios of the luminal to the choroidal area (LC ratios) in two directions (horizontal and vertical). Fifty-one patients (61%) were classified as having polyps. SV ratios in the group with polyps were significantly lower than in the group without (p < 0.001). The receiver operating characteristic (ROC) curve showed that the SV ratio was predictive of polyps (AUC 0.733, 95% CI: 0.621-0.844). In patients without polyps, horizontal LC ratios were significantly higher in a subgroup with subretinal fluid than in those without (p = 0.047). The ROC curve showed that the LC ratio was predictive of subretinal fluid (AUC 0.722, 95% CI: 0.517-0.926). The SV ratio reflects the MNV disease type, whereas the LC ratio reflects MNV disease activity. Establishing cut-off values for each ratio may be useful for MNV diagnosis.

Long term clinical outcome of sirolimus drug coated balloons in large coronary vessels.

Studies evaluating the safety and efficacy of drug coating balloons (DCB) for the treatment of lesions in large coronary vessel are limited. Our study aimed to evaluate the performance of a sirolimus DCB in large coronary arteries. We analyzed all the procedures included in the EASTBOURNE Registry (NCT03085823) enrolling patients with a clinical indication to percutaneous coronary intervention performed by a sirolimus DCB according to investigator judgment. In the present analysis, a cut-off of 2.75 mm was used to define large coronary arteries. Primary endpoint of the study was clinically driven target lesion revascularization (TLR) at 24 months whereas secondary endpoint included procedural success, myocardial infarction (MI), cardiac death and total mortality. Among the 2123 patients and 2440 lesions enrolled in the EASTBOURNE study between 2016 and 2020, 757 patients/810 lesions fulfilled the criteria for the present analysis. Mean reference vessel diameter was 3.2 ± 0.3 mm with mean lesion length of 22 ± 7 mm. Procedural success was high (96%) and at 2-year follow up the device showed a good efficacy with a TLR rate of 9%. There were 34 deaths (4.5%), 30 MIs (4%) and 8 BARC type 3-5 bleedings (1.1%). In-stent restenosis (629 lesions) and de novo lesions (181) were associated with 11% and 4% rates of TLR at 2 years, respectively (p = 0.003). Clinical performance of a sirolimus DCB in large coronary artery vessels shows promising signals at 2-year follow up, both in de novo and in-stent restenosis lesions.

Phytochemical evaluation, embryotoxic, and teratogenic effects of Buwakan (Decalobanthus peltatus (L.) A.R.Simões & Staples) leaf extracts on duck embryo.

Decalobanthus peltatus is a woody vine that is commonly utilized in traditional Southeast Asian medicinal preparations. Despite the documented therapeutic uses of D. peltatus, there is hardly any information regarding its toxic effects on its consumers. In this study, crude leaf extracts (aqueous, methanol, ethyl acetate, and hexane) from D. peltatus were prepared and evaluated for their embryotoxicity and teratogenic effects. Phytochemical screening of bioactive compounds from the plants showed the presence of alkaloids, flavonoids, saponins, steroids, and tannins. In addition, investigations on the toxicity of the crude leaf extracts were determined using brine shrimp lethality assay, in which the LC50 was calculated. Results showed that the ethyl acetate leaf extract was the most toxic among the crude leaf extracts, with an LC50 of 14.54 ppm. Based on this result, ethyl acetate leaf extract was treated on duck embryos, and the alteration of vascular branching patterns in the chorioallantoic membrane was quantified. Gross morphological and histological analysis of the skin tissues from the treated duck embryos were also examined. We found significant reduction of primary and tertiary vessel diameters in the duck embryos treated with ethyl acetate leaf extracts in both concentrations compared to the control group. Treated duck embryos exhibited gross malformations, growth retardation, and hemorrhages on the external body surfaces at 1000 ppm. Histopathological analysis of the skin tissues from the 14-day-old treated duck embryos showed a reduced number of feather follicles compared to the control group. These results suggest that D. peltatus crude leaf extracts present risks when taken in significant dosages and comprehensive toxicity testing on therapeutic herbs should be performed to ensure their safety on the consumers.

Microvascular disease not type 2 diabetes is associated with increased cortical porosity: A study of cortical bone microstructure and intracortical vessel characteristics

IntroductionFracture risk is elevated in type 2 diabetes (T2D) despite normal or even high bone mineral density (BMD). Microvascular disease (MVD) is a diabetic complication, but also associated with other diseases, for example chronic kidney disease. We hypothesize that increased fracture risk in T2D could be due to increased cortical porosity (Ct.Po) driven by expansion of the vascular network in MVD. The purpose of this study was to investigate associations of T2D and MVD with cortical microstructure and intracortical vessel parameters. MethodsThe study group consisted of 75 participants (38 with T2D and 37 without T2D). High-resolution peripheral quantitative CT (HR-pQCT) and dynamic contrast-enhanced MRI (DCE-MRI) of the ultra-distal tibia were performed to assess cortical bone and intracortical vessels (outcomes). MVD was defined as ≥1 manifestation including neuropathy, nephropathy, or retinopathy based on clinical exams in all participants. Adjusted means of outcomes were compared between groups with/without T2D or between participants with/without MVD in both groups using linear regression models adjusting for age, sex, BMI, and T2D as applicable. ResultsMVD was found in 21 (55 %) participants with T2D and in 9 (24 %) participants without T2D. In T2D, cortical pore diameter (Ct.Po.Dm) and diameter distribution (Ct.Po.Dm.SD) were significantly higher by 14.6 μm (3.6 %, 95 % confidence interval [CI]: 2.70, 26.5 μm, p = 0.017) and by 8.73 μm (4.8 %, CI: 0.79, 16.7 μm, p = 0.032), respectively. In MVD, but not in T2D, cortical porosity was significantly higher by 2.25 % (relative increase = 12.9 %, CI: 0.53, 3.97 %, p = 0.011) and cortical BMD (Ct.BMD) was significantly lower by −43.6 mg/cm3 (2.6 %, CI: −77.4, −9.81 mg/cm3, p = 0.012). In T2D, vessel volume and vessel diameter were significantly higher by 0.02 mm3 (13.3 %, CI: 0.004, 0.04 mm3, p = 0.017) and 15.4 μm (2.9 %, CI: 0.42, 30.4 μm, p = 0.044), respectively. In MVD, vessel density was significantly higher by 0.11 mm−3 (17.8 %, CI: 0.01, 0.21 mm−3, p = 0.033) and vessel volume and diameter were significantly lower by −0.02 mm3 (13.7 %, CI: −0.04, −0.004 mm3, p = 0.015) and − 14.6 μm (2.8 %, CI: −29.1, −0.11 μm, p = 0.048), respectively. ConclusionsThe presence of MVD, rather than T2D, was associated with increased cortical porosity. Increased porosity in MVD was coupled with a larger number of smaller vessels, which could indicate upregulation of neovascularization triggered by ischemia. It is unclear why higher variability and average diameters of pores in T2D were accompanied by larger vessels.

The neurovascular retinal involvement in a large population of patients recovered from COVID-19: an OCT and OCT angiography study.

This study aimed to assess the neuronal and microvascular retinal and choroidal involvement in COVID-19 recovered patients using optical coherence tomography (OCT) and OCT angiography (OCTA). This observational cross-sectional study recruited patients recovered from COVID-19 and a group of healthy controls for comparisons. OCT (peripapillary scan and macular map) and OCTA (macular map) were performed to obtain: the central subfield thickness (CST), the macular volume (MV), the peripapillary retinal nerve fibre layer (pRNFL) thickness, the vessel area density (VAD), vessel length fraction (VLF), vessel diameter index (VDI) and fractal dimension (FD) of the superficial vascular plexus (SVP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP), and the vessel density (VD), stromal density (SD) and vascular/stromal (V/S) ratio of the choriocapillaris (CC) and choroid (Ch). Data regarding disease severity, administered therapy and prior comorbidities were collected. We recruited 676 eyes from 338 patients and 98 eyes from 49 healthy controls. VAD of all the three retinal plexuses, VLF and VDI of ICP and DCP and VD of CC were significantly reduced in patients versus controls. No differences were found in CST, MV and pRNFL. A multivariate analysis showed that oxygen therapy, previous cardio/cerebrovascular events and hypertension negatively influenced vascular parameters. A microvascular retinal and choriocapillaris damage may be identified secondary to SARS-CoV-2 infection, even after recovery. OCTA may represent a reproducible and non-invasive tool to assess microangiopathy in these patients, with particular regard to those with previous cardio/cerebrovascular events, hypertension and those who received oxygen therapy.

Radial Variation of Wood Anatomical Characteristics and Maturation Ages of Six Korean Oak Species

The objective of this study was to examine and compare radial variation of the anatomical characteristics and the transition age from juvenile to mature wood of the six Korean oak wood species: Quercus variabilis (Qv), Quercus serrata (Qs), Quercus mongolica (Qm), Quercus dentata (Qd), Quercus aliena (Qal), and Quercus acutissima (Qac). Quantitative anatomical features were observed from the pith to the bark at five growth-ring intervals using optical microscopy. A segmented regression model was used to evaluate the transition from juvenile wood to mature wood. The clearest transition from juvenile to mature wood was observed in the radial variation of the earlywood vessel diameter and fiber length. The maturation age of the six Korean oak species ranged from 19 to 44 years. Qv exhibited the highest values for latewood vessel diameter, fiber length, and fiber diameter. Qac displayed the highest values for earlywood vessel diameter and fiber wall thickness. The highest fiber lumen diameter was observed for Qm. The differences in earlywood and latewood vessel diameters and fiber lengths could be utilized as identification keys for these species. Earlywood vessel diameter and fiber length have emerged as the most reliable indicators for estimating the transition from juvenile to mature wood.

Soft electrodes for simultaneous bio-potential and bio-impedance study of the face

The human body’s vascular system is a finely regulated network: blood vessels can change in shape (i.e. constrict, or dilate), their elastic response may shift and they may undergo temporary and partial blockages due to pressure applied by skeletal muscles in their immediate vicinity. Simultaneous measurement of muscle activation and the corresponding changes in vessel diameter, in particular at anatomical regions such as the face, is challenging, and how muscle activation constricts blood vessels has been experimentally largely overlooked. Here we report on a new electronic skin technology for facial investigations to address this challenge. The technology consists of screen-printed dry carbon electrodes on soft polyurethane substrate. Two dry electrode arrays were placed on the face: One array for bio-potential measurements to capture muscle activity and a second array for bio-impedance. For the bio-potential signals, independent component analysis (ICA) was used to differentiate different muscle activations. Four-contact bio-impedance measurements were used to extract changes (related to artery volume change), as well as beats per minute (BPM). We performed concurrent bio-potential and bio-impedance measurements in the face. From the simultaneous measurements we successfully captured fluctuations in the superficial temporal artery diameter in response to facial muscle activity, which ultimately changes blood flow. The observed changes in the face, following muscle activation, were consistent with measurements in the forearm and were found to be notably more intricate. Both at the arm and the face, a clear increase in the baseline impedance was recorded during muscle activation (artery narrowing), while the impedance changes signifying the pulse had a clear repetitive trend only at the forearm. These results reveal the direct connection between muscle activation and the blood vessels in their vicinity and start to unveil the complex mechanisms through which facial muscles might modulate blood flow and possibly affect human physiology.

Comparison of Radiofrequency Ablation and Cyanoacrylate Closure for Large-Diameter Great Saphenous Vein Insufficiency

ObjectiveTo compare radiofrequency ablation (RFA) and cyanoacrylate closure (CAC) for large-diameter great saphenous vein insufficiency (GSV) between diameters of 12 and 16 mm. Material-MethodsThis study is a single-centre retrospective study. Subjects who underwent endovenous treatment with RFA (Group A) or CAC (Group B) for GSV insufficiency between June 2015 and June 2021 who were followed up for at least 2 years were included in the study. Subjects who had a 12 to 16 mm target vessel diameter and subjects with grade 3 and grade 4 reflux were included. Subjects’ demographic data (age, sex), body mass indices (BMI), clinical, aetiological, anatomic, pathophysiologic (CEAP) classification, GSV diameter, reflux grade, target vessel length, preoperative venous clinical severity score (VCSS), procedural time, postoperative 1st-day pain scores, postoperative 14th-day patient satisfaction scale and postoperative complications were noted. In follow-up, subjects were evaluated with duplex ultrasonography and VCSS at 1, 6, 12 and 24 months. ResultsIn total, 142 subjects were included (n=71 for both groups). The mean GSV diameter was 13,21±1,00 for Group A and 13,51±0,97 for Group B. The groups did not differ in terms of age, sex, BMI, CEAP classification, GSV diameter, reflux grade, target GSV length, preoperative VCSS, complications, postoperative 24-hour pain status or postoperative 14-day patient satisfaction scale (p>0.05 for all comparisons). The procedure time was significantly shorter in Group B (34,68±4,22 min for Group A vs. 22,59±4,5 min for Group B, p=0,001). In the 1-month and 6-month Duplex ultrasonography of the subjects, partial closure and patency rates in Group B were significantly higher than those in Group A (p=0.003 and p=0.025, respectively). At the 12- and 24-month evaluation, closure rates did not show a statistically significant difference between the groups (p=0.056 and p=0.090, respectively). Preoperative and 1-month VCSS measurements did not show a statistically significant difference between groups (p>0.05 for all comparisons). The 6- and 12-month 24-month VCSS measurements of Group A were significantly higher than those in Group B. (p=0.043, p=0.009 and p=0.002, respectively). ConclusionBoth RFA and CAC were found to be effective in the treatment of large-diameter GSV incompetency. The complication rates were similar between the two techniques. CAC had a shorter procedure time. Although the closure rates in the early postoperative period were better in the RFA group, long-term follow-up demonstrated similar patency rates. The functional results in the long-term follow-up were better in the RFA group.

Treatment of Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage using the Neurospeed Semi-compliant Balloon.

Cerebral vasospasm (CV) following aneurysmal subarachnoid hemorrhage (aSAH) may lead to morbidity and mortality. Endovascular mechanical angioplasty may be performed if symptomatic CV is refractory to noninvasive medical management. Off-label compliant remodelling balloons tend to conform to the course of the vessel, contrary to noncompliant or semi-compliant balloons. Our objective is to describe our initial experience with the semi-compliant Neurospeed balloon (approved for intracranial stenosis) in cerebral vasospasm treatment following aSAH. All patients included in the prospective observational SAVEBRAIN PWI (NCT05276934 on clinicaltrial.gov) study who underwent cerebral angioplasty using the Neurospeed balloon for the treatment of medically refractory and symptomatic CV after aSAH were identified. Patient demographic information, procedural details and outcomes were obtained from electronic medical records. Between February 2022 and June 2023, 8consecutive patients underwent CV treatment with the Neurospeed balloon. Angioplasty of 48arterial segments (supraclinoid internal carotid artery, A1and A2segments of the anterior cerebral artery, M1and M2segments of the middle cerebral artery) was attempted and 44/48 (92%) were performed. The vessel diameter significantly improved following angioplasty (+81%), while brain hypoperfusion decreased (-81% of the mean TMax). There was no long-term clinical complication, 4% periprocedural complications occurred. The semi-compliant Neurospeed balloon is effective in the treatment of cerebral vasospasm following aSAH, bringing anew device into the armamentarium of the neurointerventionalist to perform intracranial angioplasty.

Linkages among stem xylem transport, biomechanics, and storage in lianas and trees across three contrasting environments.

Stem xylem transports water and nutrients, mechanically supports aboveground tissues, and stores water and nonstructural carbohydrates. These three functions are associated with three types of cells-vessel, fiber, and parenchyma, respectively. We measured stem theoretical hydraulic conductivity (Kt), modulus of elasticity (MOE), tissue water content, starch, soluble sugars, cellulose, and xylem anatomical traits in 15 liana and 16 tree species across three contrasting sites in Southwest China. Lianas had higher hydraulic efficiency and tissue water content, but lower MOE and cellulose than trees. Storage traits (starch and soluble sugars) did not significantly differ between lianas and trees, and trait variation was explained mainly by site, highlighting how environment shapes plant storage strategies. Kt was significantly positively correlated with vessel diameter and vessel area fraction in lianas and all species combined. The MOE was significantly positively correlated with fiber area fraction, wood density, and cellulose in lianas and across all species. The tissue water content was significantly associated with parenchyma area fraction in lianas. Support function was strongly linked with transport and storage functions in lianas. In trees, transport and support functions were not correlated, while storage function was tightly linked with transport and support functions. These findings enhance our understanding of the relationship between stem xylem structure and function in lianas and trees, providing valuable insights into how plants adapt to environmental changes and the distinct ecological strategies employed by lianas and by trees to balance the demands of hydraulic transport, mechanical support, and storage.

Molecular Mechanisms Underlying Vascular Remodeling in Hypertension.

Hypertension, a common cardiovascular disease, is primarily characterized by vascular remodeling. Recent extensive research has led to significant progress in understanding its mechanisms. Traditionally, vascular remodeling has been described as a unidirectional process in which blood vessels undergo adaptive remodeling or maladaptive remodeling. Adaptive remodeling involves an increase in vessel diameter in response to increased blood flow, while maladaptive remodeling refers to the narrowing or thickening of blood vessels in response to pathological conditions. However, recent research has revealed that vascular remodeling is much more complex. It is now understood that vascular remodeling is a dynamic interplay between various cellular and molecular events. This interplay process involves different cell types, including endothelial cells, smooth muscle cells, and immune cells, as well as their interactions with the extracellular matrix. Through these interactions, blood vessels undergo intricate and dynamic changes in structure and function in response to various stimuli. Moreover, vascular remodeling involves various factors and mechanisms such as the renin-angiotensin-aldosterone system (RAS), oxidative stress, inflammation, the extracellular matrix (ECM), sympathetic nervous system (SNS) and mechanical stress that impact the arterial wall. These factors may lead to vascular and circulatory system diseases and are primary causes of long-term increases in systemic vascular resistance in hypertensive patients. Additionally, the presence of stem cells in adventitia, media, and intima of blood vessels plays a crucial role in vascular remodeling and disease development. In the future, research will focus on examining the underlying mechanisms contributing to hypertensive vascular remodeling to develop potential solutions for hypertension treatment. This review provides us with a fresh perspective on hypertension and vascular remodeling, undoubtedly sparking further research efforts aimed at uncovering more potent treatments and enhanced preventive and control measures for this disease.