Studies of Isolated Small Vessels and Myometrium from the Human Uteroplacental Unit

2015 ◽  
pp. 75-81 ◽  
Author(s):  
S. Maigaard ◽  
D. H�gest�tt ◽  
A. Forman ◽  
K. E. Andersson
Keyword(s):  
Small Vessels

Vasculitis leucocitoclástica asociada a medicamentos

2019 ◽  
Vol 1 (1) ◽  
pp. 110-114
Author(s):  
Angélica María Hernández Fernández ◽  
José Antonio Flores Vargas
Keyword(s):  
Female Patient ◽  
Leukocytoclastic Vasculitis ◽  
Thrombocytopenic Purpura ◽  
Case Presentation ◽  
Small Vessels ◽  
Nuclear Dust

Introduction. Leukocytoclastic vasculitis (LV) is the presence of leukocytoclasis (fragmentation of the nuclei of neutrophils or "nuclear dust") in the wall of small vessels and around them. Case Presentation. A 37-yearold female patient with a diagnosis of thrombocytopenic purpura who starts treatment with ceftazidime and phenytoin, which causes LV. Conclusions. The case presented is associated with pharmacological etiology because the patient does not present a concomitant etiological condition.

Drug-Coated Balloons Applications in Interventional Cardiology

2018 ◽  
Vol 24 (4) ◽  
pp. 397-401
Author(s):  
Gianluca Rigatelli ◽  
Marco Zuin
Keyword(s):  
Interventional Cardiology ◽  
Vessel Diameter ◽  
Peripheral Artery ◽  
Small Vessels ◽  
Below The Knee ◽  
Stent Restenosis ◽  
Normal Vessel ◽  
Drug Eluting ◽  
Artery Disease ◽  
And Function

Backgrounds: Drug coated balloons (DCBs) are new on stented-based anti-proliferative drug delivery systems, recently introduced in interventional cardiology. Their primary aim is to transfer an anti-proliferative drug to reduce the subsequent neo-intima hyperplasia and to maintain the normal vessel diameter and function. Methods: A review of the most recent influential studies about DCBs in all the fields of interventional cardiology has been performed. Results: As demonstrated by different studies, DCBs have different theoretical advantages over Drug Eluting Stents (DESs), especially for the treatment of some endovascular lesions, as In-Stent Restenosis (ISR), coronary bifurcations, small vessels disease and peripheral artery disease at femoropopliteal and below the knee sites. Conclusion: Despite the need of further studies are needed to elucidate the optimal use of DCBs their current use in interventional cardiology appears promising.

scholarly journals Retinal Vessel Segmentation by Deep Residual Learning with Wide Activation

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yuliang Ma ◽  
Xue Li ◽  
Xiaopeng Duan ◽  
Yun Peng ◽  
Yingchun Zhang
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Area Under The Curve ◽  
Retinal Vessel ◽  
Vessel Segmentation ◽  
Superior Performance ◽  
Retinal Blood Vessel ◽  
Low Contrast ◽  
Blood Vessel Segmentation ◽  
Small Vessels

Purpose. Retinal blood vessel image segmentation is an important step in ophthalmological analysis. However, it is difficult to segment small vessels accurately because of low contrast and complex feature information of blood vessels. The objective of this study is to develop an improved retinal blood vessel segmentation structure (WA-Net) to overcome these challenges. Methods. This paper mainly focuses on the width of deep learning. The channels of the ResNet block were broadened to propagate more low-level features, and the identity mapping pathway was slimmed to maintain parameter complexity. A residual atrous spatial pyramid module was used to capture the retinal vessels at various scales. We applied weight normalization to eliminate the impacts of the mini-batch and improve segmentation accuracy. The experiments were performed on the DRIVE and STARE datasets. To show the generalizability of WA-Net, we performed cross-training between datasets. Results. The global accuracy and specificity within datasets were 95.66% and 96.45% and 98.13% and 98.71%, respectively. The accuracy and area under the curve of the interdataset diverged only by 1%∼2% compared with the performance of the corresponding intradataset. Conclusion. All the results show that WA-Net extracts more detailed blood vessels and shows superior performance on retinal blood vessel segmentation tasks.

scholarly journals Mathematical Models for Some Aspects of Blood Microcirculation

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1020
Author(s):  
Angiolo Farina ◽  
Antonio Fasano ◽  
Fabio Rosso
Keyword(s):  
Blood Flow ◽  
Mathematical Models ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Blood Rheology ◽  
Small Class ◽  
Small Vessels ◽  
Blood Microcirculation ◽  
Peculiar Behavior

Blood rheology is a challenging subject owing to the fact that blood is a mixture of a fluid (plasma) and of cells, among which red blood cells make about 50% of the total volume. It is precisely this circumstance that originates the peculiar behavior of blood flow in small vessels (i.e., roughly speaking, vessel with a diameter less than half a millimeter). In this class we find arteriolas, venules, and capillaries. The phenomena taking place in microcirculation are very important in supporting life. Everybody knows the importance of blood filtration in kidneys, but other phenomena, of not less importance, are known only to a small class of physicians. Overviewing such subjects reveals the fascinating complexity of microcirculation.

scholarly journals POS0832 A NOVEL GREY SCALE AND POWER DOPPLER ULTRASONOGRAPHIC SCORE FOR IDIOPATHIC INFLAMMATORY MYOPATHIES: SIENA MYOSITIS ULTRASOUND GRADING SCALE

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 669.1-670
Author(s):  
E. Conticini ◽  
P. Falsetti ◽  
S. G. Al Khayyat ◽  
C. Baldi ◽  
F. Bellisai ◽  
...  
Keyword(s):  
Disease Duration ◽  
Muscle Fibers ◽  
Power Doppler ◽  
Muscle Thickness ◽  
Rectus Femoris ◽  
Normal Muscle ◽  
Small Vessels ◽  
Grey Scale ◽  
Vastus Intermedius ◽  
Grading Scale

Background:No clear-cut guidelines exist about the use of diagnostic procedures for idiopathic inflammatory myopathies (IIM) and only scanty and conflicting data report the use of ultrasound (US).Objectives:We aimed to assess if grey-scale (GS) and Power Doppler (PD) US, graded with a 0-3-points-scale, may be a reliable tool in a cohort of patients affected by IIM.Methods:We prospectively collected, since July to October 2020, all patients referred to Vasculitis and Myositis clinic, Rheumatology Unit, University of Siena, for suspected IIM, as well as patients with a previous, definite diagnosis of IIM and evaluated during follow-up or referred from other centers for a second opinion. All patients underwent US examination of both thighs in axial and longitudinal scans. Edema and atrophy, both assessed in GS, and PD, were graded with a 0-3-points-scale. Spearman test was used to identify the correlations between US and clinical and serological variables.Results:A total of 18 patients was included. Four of them were evaluated twice, at baseline and within 3 months of therapy. Muscle edema was found to be directly correlated with physician global assessment (PhGA), serum myoglobin and PD and negatively with disease duration. PD score was positively correlated to PhGA and negatively to disease duration. Muscle atrophy directly correlated with Myositis Damage Index and patients’ age. The single-thigh sub-analysis evidenced a direct correlation between PD score and Manual Muscle Test.Conclusion:In our cohort, we found that edema and PD are strictly related to early, active myositis, suggesting that an inflamed muscle should appear swollen, thickened and with Doppler signal. Conversely, muscle atrophy reflects the age of the patient and the overall severity of the disease. Such findings shed a new, promising, light in the role of US in diagnosis and monitoring of IIMs.Table 1.Siena Myositis Ultrasound Grading Scale (SMUGS).Grey-scale edemaGrey-scale atrophyPower Doppler0Normal muscle echotexture with hyperechoic septa and hypoechoic muscle fibers, conserved thickness.Normal muscle echotexture, with hyperechoic septa and hypoechoic muscle fibers, conserved thickness.No PD signal.1Focal hypoechoic areas, where septa are less evident. Conserved thickness.Focal heterogeneously hyperechoic areas, where septa are thicker and more evident, and muscle fibers are thinner. Conserved muscle thickness.One or two PD signals in at least one muscle (PD vascular spots, small vessels of homogenous diameters, vessel diameters approximately not superior to fibrous intramuscular septa)2Diffuse and heterogeneous hypo echogenicity (rectus femoris as hypoechoic or more than vastus intermedius), septa diffusely less evident. Conserved thickness.Diffuse and heterogeneously hyperechoic muscle, with thicker septa and thinner muscle fibers. Conserved muscle thickness.More than 2 PD signals for each muscle (as vascular spots, small vessels of homogenous diameters, vessel diameters approximately not superior to fibrous intramuscular septa).3Diffuse and heterogeneous hypo echogenicity (rectus femoris as hypoechoic or more than vastus intermedius), septa diffusely less evident. Increased thickness (rectus femoris became thicker than vastus intermedius).Diffuse and heterogeneously hyperechoic muscle, with thicker septa and thinner muscle fibers. Reduced muscle thickness.More than 2 PD signals for each muscle with larger diameter of the vessel (at least superior to fibrous intramuscular septa), or vessels with different diameters or branched vessels.Figure 1.Different PD findings (clockwise) in longitudinal anterior scans of the thigh: PD 3 in a patient with a recent diagnosis of anti-Mi2 DM; PD 2 in the same patient after one month of treatment with steroids and Methotrexate; PD 1 in a patient affected by anti-SAE DM, with a suspected disease flare; PD 0 in a patient affected by an advanced polymyositis diagnosed in 2000, currently not in treatment.Disclosure of Interests:None declared

scholarly journals On the measurement of the ratio of the specific heats using small volumes of gas.—The ratios of the specific heat of air and of hydrogen at atmospheric pressure and a temperatures between 20°C. and —183°C

1925 ◽  
Vol 107 (743) ◽  
pp. 510-543 ◽  
Keyword(s):  
Systematic Error ◽  
Low Temperatures ◽  
Room Temperature ◽  
Expansion Chamber ◽  
Small Vessels ◽  
Specific Heats ◽  
Large Expansion ◽  
Before And After ◽  
The One ◽  
Chamber Capacity

Introduction .—In nearly all the previous determinations of the ratio of the specific heats of gases, from measurements of the pressures and temperature before and after an adiabatic expansion, large expansion chambers of fror 50 to 130 litres capacity have been used. Professor Callendar first suggests the use of smaller vessels, and in 1914, Mercer (‘Proc. Phys. Soc.,’ vol. 26 p. 155) made some measurements with several gases, but at room temperature only, using volumes of about 300 and 2000 c. c. respectively. He obtained values which indicated that small vessels could be used, and that, with proper corrections, a considerable degree of accuracy might be obtained. The one other experimenter who has used a small expansion chamber, capacity about 1 litre, is M. C. Shields (‘Phys. Rev.,’ 1917), who measured this ratio for air and for hydrogen at room temperature, about 18° C., and its value for hydroger at — 190° C. The chief advantage gained by the use of large expansion chambers is that no correction, or at the most, a very small one, has to be made for any systematic error due to the size of the containing vessels, but it is clear that, in the determinations of the ratio of the specific heats of gases at low temperatures, the use of small vessels becomes a practical necessity in order that uniform and steady temperature conditions may be obtained. Owing, however, to the presence of a systematic error depending upon the dimensions of the expansion chamber, the magnitude of which had not been definitely settled by experiment, the following work was undertaken with the object of investigating the method more fully, especially with regard to it? applicability to the determination of this ratio at low temperatures.

Sign in / Sign up

Export Citation Format

Share Document