scholarly journals Radiofrequency tumor ablation system with a wireless or implantable probe

2020 ◽  
Vol 7 (2) ◽  
pp. 95-105
Author(s):  
Julian Moore ◽  
Sheng Xu ◽  
Bradford J. Wood ◽  
Hongliang Ren ◽  
Zion Tsz Ho Tse
Keyword(s):  
Power Efficiency ◽  
Electromagnetic Induction ◽  
Ex Vivo ◽  
Electrical Current ◽  
The Body ◽  
Maximum Efficiency ◽  
Prototype System ◽  
Ablation Zone ◽  
Received Power ◽  
Average Maximum

AbstractRadiofrequency ablation (RFA) is a non-invasive image-guided procedure where tumors are heated in the body with electrical current. RFA procedures are commonly indicated for patients with limited local disease or who are not surgical candidates. Current methods of RFA use multiple cords and wires that ergonomically complicate the procedure and present the risk of cutting or shorting the circuit if they are damaged. A wireless RFA technique based on electromagnetic induction is presented in this paper. The transmitting and receiving coils were coupled to resonate at the same frequency to ensure the highest power output. The receiving coil was connected to two insulated electrodes on a catheter, which allowed the current to flow to the targeted tissue. The prototype system was tested with ex-vivo bovine tissue, which has similar thermal and electrical properties to human tissue. The setup can monitor the received power, efficiency, temperature, and ablation zone during ablation procedures. The maximum received power was 15 W, and the average maximum efficiency was 63.27%. The novel system was also able to ablate up to a 2 cm ablation zone in non-perfused tissue. This proof of concept for performing RFA wirelessly with electromagnetic induction may merit further optimization.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

The Role of Computer Modeling in Electrocardiography

1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom
Keyword(s):  
Electrical Activity ◽  
Computer Modeling ◽  
Body Surface ◽  
Electrical Current ◽  
The Body ◽  
Volume Conductor ◽  
Current Generator ◽  
Cardiac Electrical Activity ◽  
Source Models

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.

scholarly journals Analysis of the ex-vivo transformation of semen, saliva and urine as they dry out using ATR-FTIR spectroscopy and chemometric approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tanurup Das ◽  
Abhimanyu Harshey ◽  
Ankit Srivastava ◽  
Kriti Nigam ◽  
Vijay Kumar Yadav ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Ex Vivo ◽  
Body Fluids ◽  
Biochemical Changes ◽  
Partial Least Square ◽  
The Body ◽  
Slow Phase ◽  
Time Since Deposition ◽  
Dry Out

AbstractThe ex-vivo biochemical changes of different body fluids also referred as aging of fluids are potential marker for the estimation of Time since deposition. Infrared spectroscopy has great potential to reveal the biochemical changes in these fluids as previously reported by several researchers. The present study is focused to analyze the spectral changes in the ATR-FTIR spectra of three body fluids, commonly encountered in violent crimes i.e., semen, saliva, and urine as they dry out. The whole analytical timeline is divided into relatively slow phase I due to the major contribution of water and faster Phase II due to significant evaporation of water. Two spectral regions i.e., 3200–3400 cm−1 and 1600–1000 cm−1 are the major contributors to the spectra of these fluids. Several peaks in the spectral region between 1600 and 1000 cm−1 showed highly significant regression equation with a higher coefficient of determination values in Phase II in contrary to the slow passing Phase I. Principal component and Partial Least Square Regression analysis are the two chemometric tool used to estimate the time since deposition of the aforesaid fluids as they dry out. Additionally, this study potentially estimates the time since deposition of an offense from the aging of the body fluids at the early stages after its occurrence as well as works as the precursor for further studies on an extended timeframe.

scholarly journals Dynamic Imaging of IEL-IEC Co-Cultures Allows for Quantification of CD103-Dependent T Cell Migration

2021 ◽  
Vol 22 (10) ◽  
pp. 5148
Author(s):  
Karin Enderle ◽  
Martin Dinkel ◽  
Eva-Maria Spath ◽  
Benjamin Schmid ◽  
Sebastian Zundler ◽  
...  
Keyword(s):  
T Cell ◽  
Cross Talk ◽  
Intestinal Inflammation ◽  
Ex Vivo ◽  
New Technology ◽  
Surface Expression ◽  
Intraepithelial Lymphocytes ◽  
Dynamic Imaging ◽  
The Body ◽  
Therapeutic Interventions

Intraepithelial lymphocytes (IEL) are widely distributed within the small intestinal epithelial cell (IEC) layer and represent one of the largest T cell pools of the body. While implicated in the pathogenesis of intestinal inflammation, detailed insight especially into the cellular cross-talk between IELs and IECs is largely missing in part due to lacking methodologies to monitor this interaction. To overcome this shortcoming, we employed and validated a murine IEL-IEC (organoids) ex vivo co-culture model system. Using livecell imaging we established a protocol to visualize and quantify the spatio-temporal migratory behavior of IELs within organoids over time. Applying this methodology, we found that IELs lacking CD103 (i.e., integrin alpha E, ITGAE) surface expression usually functioning as a retention receptor for IELs through binding to E-cadherin (CD324) expressing IECs displayed aberrant mobility and migration patterns. Specifically, CD103 deficiency affected the ability of IELs to migrate and reduced their speed during crawling within organoids. In summary, we report a new technology to monitor and quantitatively assess especially migratory characteristics of IELs communicating with IEC ex vivo. This approach is hence readily applicable to study the effects of targeted therapeutic interventions on IEL-IEC cross-talk.

scholarly journals Effect of grazing period management on growth performances of camel in climate change condition

2019 ◽  
Author(s):  
Champak Bhakat
Keyword(s):  
Climate Change ◽  
Body Weight ◽  
Weight Gain ◽  
Body Weight Gain ◽  
The Body ◽  
Maximum Temperature ◽  
Change Condition ◽  
Average Maximum ◽  
Group 2 ◽  
Group 1

In order to decide the optimum time of grazing for camels during hot summer months, 10 growing camel calveswere divided into 2 equal groups. First group was sent for grazing during 10:00 h to 16:00 h daily and second groupallowed for grazing during thermo neutral period. The climatic variables were recorded daily (April 2012 to March2013). The average daily gain and total body weight gain in calves sent for grazing during relatively cool parts ofday (group 2) was significantly higher as compared to group 1 calves sent as per routine farm schedule. Theaverage intake of fodder and water from manger was higher in group 1 calves. The average DMI from manger forgroup 1 calves was higher as compared to group 2 calves. The comparative biometrics of camel calves in differentgrazing management practices revealed that body length, heart girth, height at wither, neck length were significantly(P<0.01) higher in group 2 calves as compared to group 1 calves. After 180 days of experimentation, humpcircumference vertical and hind leg length were significantly (P<0.05) increased in group 2 as compared to group1. Analysis of recorded data of climatic parameters revealed that average maximum temperature was higher duringJune 2012. The values of THI also were higher in monsoon and post monsoon months hence the practice of sendingcamel calves during relatively comfortable part of hot and hot humid months was successful in getting good growth.The relative humidity was significantly higher during morning as compared to evening period for all months. TheTHI was significantly lower during morning as compared to evening hours for all months in different climate forwhole year. Economic analysis reveals that the cost of feed per kg body weight gain was quite less in group 2 ascompared to group 1. So the practice of grazing of camel calves during cool hours of day remain profitable forfarmers by looking at the body weight gain and better body conformation in climate change condition.

scholarly journals Arrhythmiarizikó és cardialis szövődmények áramütéses balesetet követően

2020 ◽  
Vol 161 (47) ◽  
pp. 1979-1988
Author(s):  
Dávid Pilecky ◽  
Enikő Kovács ◽  
Endre Zima
Keyword(s):  
Emergency Department ◽  
Low Voltage ◽  
Electrical Current ◽  
Developed Countries ◽  
The Body ◽  
Cardiac Complications ◽  
Special Focus ◽  
Severe Injuries ◽  
Multiple Organs ◽  
Severe Burns

Összefoglaló. Az áramütés súlyos esetben hirtelen halállal vagy több szervrendszer kiterjedt károsodásával járhat. A magasfeszültségű áramütés (>1000 V) általában súlyosabb égési sérülésekkel és magasabb kórházi mortalitással jár, mint az alacsonyfeszültségű, de a sérülések súlyosságát a feszültségen kívül a test ellenállása, az áramexpozíció ideje, az áram fajtája, erőssége és útja is befolyásolja. A kritikus állapotú vagy súlyos égési sérüléseket szenvedett betegek sürgősségi ellátása komplex és multidiszciplináris szemléletet igényel. A súlyos szövődményekkel járó áramütéses balesetek ugyanakkor a fejlett országokban ritkák: az áramütés következtében sürgősségi osztályon jelentkező betegek döntő többsége panaszmentesen vagy minor panaszokkal kerül felvételre. A ritmuszavarok az áramütéses balesetek messze leggyakoribb cardialis szövődményei, és rendszerint közvetlenül az áramütés után jelentkeznek. Az elektromos áram kamrafibrillációt vagy asystoliát is kiválthat, mely a baleset helyszínén ellátás nélkül halálhoz vezethet. Bár sok helyen elterjedt gyakorlat az áramütést szenvedett betegek rutinszerű monitorozása, a klinikailag releváns arrhythmiák összességében ritkák, és a felvételi EKG alapján diagnosztizálhatók, ezért EKG-monitorozás csak meghatározott rizikófaktorok esetén szükséges. Jelen munkánk célja összefoglalni az áramütést szenvedett betegek optimális sürgősségi ellátásával kapcsolatos legfontosabb szempontokat, különös tekintettel az áramütéses balesetet követően fellépő cardialis szövődményekre és arrhythmiákra, valamint az EKG-monitorozás indikációira. Orv Hetil. 2020; 161(47): 1979–1988. Summary. Electrical accidents (EA) may cause sudden death or severe injuries of multiple organs. High voltage injuries (>1000 V) are associated with more severe burn injuries and higher in-hospital mortality than low voltage injuries, however, the severity of complications depends on several other factors like resistance of the body, duration of current exposition, intensity, type and pathway of current. Critically ill patients with severe burns and/or other injuries require a multidisciplinary intensive treatment. However, such complications are rare in the developed countries: most patients present in the emergency department with no or minor symptoms and do not require hospital admission. Arrhythmias are the most frequent cardiac complications after EA. Electrical current may cause ventricular fibrillation or asystolia which can lead to death on the scene. In patients presenting in the emergency department, clinically relevant arrhythmias are rare and can be diagnosed by a 12-lead ECG, therefore a systematic monitoring may not be indicated. Aim of our work is to review the most frequent complications after an electrical accident with special focus on cardiac complications and arrhythmias. The other aim of the manuscript is to summarize the most important aspects of emergency treatment and indication for ECG monitoring after electrical accident. Orv Hetil. 2020; 161(47): 1979–1988.

Universal Optimization Efficiency for Nonlinear Irreversible Heat Engines

2017 ◽  
Vol 42 (3) ◽  
Author(s):  
Yanchao Zhang ◽  
Juncheng Guo ◽  
Guoxing Lin ◽  
Jincan Chen
Keyword(s):  
Objective Function ◽  
Strong Coupling ◽  
Power Efficiency ◽  
Symmetry Condition ◽  
Maximum Efficiency ◽  
Cycle Model ◽  
Trade Off ◽  
Heat Engines ◽  
Optimization Efficiency ◽  
Universal Expression

AbstractWe introduce a multi-parameter combined objective function of heat engines under the strong coupling and symmetry condition and derive the universal expression of the optimization efficiency. The results obtained show that the optimization efficiency derived from the multi-parameter combined objective function include a variety of optimization efficiencies, such as the efficiency at the maximum power, efficiency at the maximum efficiency-power state, efficiency at the maximum ecological or unified trade-off function, and Carnot efficiency. It is further explained that these results are also suitable for the endoreversible cycle model of the Carnot heat engines operating between two heat reservoirs.

Digestion in Ascidians and the Influence of Temperature

1929 ◽  
Vol 6 (3) ◽  
pp. 275-292
Author(s):  
N. J. BERRILL
Keyword(s):  
Enzyme Activity ◽  
Body Temperature ◽  
Digestive Enzymes ◽  
Alimentary Canal ◽  
The Body ◽  
Maximum Efficiency ◽  
Bile Pigment ◽  
Optimum Temperature ◽  
Different Temperatures ◽  
Pass Through

1. The mechanism of feeding and digestion in the Pyurid Ascidians Tethyum pyriforme americanum and Boltenia ovifera is described. 2. The structure and histology of the "liver" is described and it is shown that it is primarily an organ of secretion. 3. It is found that the only digestive enzymes are those poured into the gut by the liver, and consist of a powerful amylase, a protease, a very weak lipase, and also an invertase, a maltase, and a lactase. 4. The brownish pigment of the liver gives reactions with acids somewhat like those of bile pigment. There is no trace of bile salts, however, nor of cholesterol. 5. The amylase has an activity range from pH 6.0 topic pH 8.5 with an optimum near pH 7.5. The protease is active from pH 6.0 to above pH 10.0. A similar protease is secreted by Molgula citrina and Ascidia prunum. 6. The relative strengths of the amylase and protease are compared, the amylase being very much the stronger. 7. While experiments of brief duration indicate an optimum temperature for enzyme activity above 40° C, the more prolonged the experiments the lower does the optimum become. Whatever the optimum may be after an experiment of 2 hours' duration, it falls about 20° C. during the next 45 hours, if the experiments be so prolonged. 8. At 15° C. and at 10° C. the food takes about 35 and 55 hours respectively to pass through the alimentary canal, and at 50 C. somewhere between 70 and 90 hours. These temperatures approximately cover the normal range in temperature of the environment, and therefore of the animal itself. 9. From experiments lasting 33 hours the optimum temperature for enzyme activity was found to be about 17° C.; that is, within one or two degrees of the body temperature. From experiments lasting 57 hours the optimum temperature was found to be about 13° C ; that is, within three degrees of the body temperature. 10. These temperature optima not only represent the relative amounts of substrate converted at different temperatures, but also represent the absolute amounts converted and convertible. 11. The enzymes, amylase and protease, are two-thirds to three-quarters destroyed during their period of activity within the alimentary canal of the animal, and in order to utilise the remainder the digestion mixture would have to be retained within the canal for twice as long a time. 12. Therefore it seems probable that the organism in making such a compromise between a high activity of the enzyme and its economical use is working to a maximum efficiency; and it is possible that a permanent increase in the stability of the digestive enzymes would be turned to advantage through a more prolonged retention of the food within the gut.

scholarly journals 4081 Quantifying pH buffering capacity and kinetics of tumor and healthy tissue to understand and exploit differences in biology

2020 ◽  
Vol 4 (s1) ◽  
pp. 15-15
Author(s):  
A. Colleen Crouch ◽  
Emily A. Thompson ◽  
Mark D. Pagel ◽  
Erik N.K. Cressman
Keyword(s):  
Tumor Tissue ◽  
Ex Vivo ◽  
Buffering Capacity ◽  
The Body ◽  
Healthy Tissue ◽  
Buffer System ◽  
Bicarbonate Buffer ◽  
Ph Buffering ◽  
Acidocest Mri

OBJECTIVES/GOALS: The purpose of this work is to investigate natural buffering capacity of liver tissue and tumors, to understand and exploit differences for therapy. Using this work, we will determine the concentrations of reagents (acids or bases) used in ablation treatment to optimize treatment by increasing tumor toxicity and minimizing healthy tissue toxicity. METHODS/STUDY POPULATION: For this preliminary study, two methods will be used: benchtop pH experiments ex vivo and non-invasive imaging using acidoCEST MRI in vivo. For ex vivo, two types of tissues will be tested: non-cancerous liver and tumor tissue from HepG2 inoculated mice (n = 10). After mice are euthanized, pH will be measured in tissue homogenates at baseline and then the homogenates will be placed in either acidic (acetic acid) or basic (sodium hydroxide) solutions with varied concentrations (0.5–10M) and time recorded until pH returns to baseline. For in vivo imaging, Mia PaCA-2 flank model mice (n = 10) will be imaged with acidoCEST MRI to quantify pH at baseline. Mice will then be injected intratumorally with (up to 100 μL of) acid or base at increasing concentrations and imaged to quantify pH changes in the tumor. RESULTS/ANTICIPATED RESULTS: For this study, buffering capacity is defined as the concentration threshold for which tissue can buffer pH back to within normal range. Non-cancerous tissue is likely to buffer a wider range of concentrations compared to tumor tissue. From the benchtop experiment, comparison of time-to-buffer will be made for each concentration of acid/base for the two tissue types. AcidoCEST MRI will provide in vivo buffering capacity and potentially demonstrate tumor heterogeneity of buffering capacity. For both experiments, a pH vs. concentration curve for the two tissue types will allow for comparison of ex vivo to in vivo experiments, which will differentiate contributions of local tissue buffering capacity from the full body’s natural bicarbonate buffer system that depends on respiration and blood flow. DISCUSSION/SIGNIFICANCE OF IMPACT: The pH of the body must be maintained within a narrow range. With cancer, impairment in regulation of tumor metabolism causes acidosis, lowering extracellular pH in tumors. It remains unclear if pH plays a role in local recurrence or tumor toxicity. This work will determine if acidoCEST MRI can measure deliberate alteration of pH and how this change affects biology.

scholarly journals Prediction of Body Weight of a Person Lying on a Smart Mat in Nonrestraint and Unconsciousness Conditions

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3485 ◽  
Author(s):  
Tae-Hwan Kim ◽  
Youn-Sik Hong
Keyword(s):  
Neural Network ◽  
Body Weight ◽  
Evaluation Criteria ◽  
The Body ◽  
Average Error ◽  
Average Weight ◽  
Prototype System ◽  
Grid Structure ◽  
Predict Body Weight ◽  
Weight Prediction

We want to predict body weight while lying in bed for an elderly patient who is unable to move by himself/herself. To this end, we have implemented a prototype system that estimates the body weight of a person lying on a smart mat in nonrestraint and unconsciousness conditions. A total of 128 FSR (force sensing resistor) sensors were placed in a 16 × 8-grid structure on the smart mat. We formulated three methods based on the features to be applied: segmentation, average cumulative sum of pressure, and serialization. All the proposed methods were implemented with four different machine-learning models: regression, deep neural network (DNN), convolutional neural network (CNN), and random forest. We compared their performance using MAE and RMSE as evaluation criteria. From the experimental results, we chose the serialization method with the DNN model as the best model. Despite the limitations of the presence of dead space due to the wide spacing between the sensors and the small dataset, the MAE and the RMSE of the body weight prediction of the proposed method was 4.608 and 5.796, respectively. That is, it showed an average error of ±4.6 kg for the average weight of 72.9 kg.

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