scholarly journals Extracorporeal ultrasound exposure by the low-frequency acoustic amplitude-modulated signal on a ureteral stent for preventing its incrustation: experimental determination of optimal application points

2021 ◽  
Vol 9 (3) ◽  
pp. 70-78
Author(s):  
A. Yu. Tsukanov ◽  
D. S. Akhmetov ◽  
A. A. Novikov ◽  
N. A. Negrov ◽  
A. R. Putintseva ◽  
...  
Keyword(s):  
Low Frequency ◽  
Ureteral Stent ◽  
Economic Losses ◽  
Anatomical Landmarks ◽  
Excessive Heat ◽  
Posterior Axillary Line ◽  
Pulsed Mode ◽  
Ultrasound Intensity ◽  
Ultrasonic Intensity ◽  
Acoustic Exposure

Introduction. Incrustation and biofilms formation on the surface of ureteral stents are still the most significant complications of internal drainage of the upper urinary tract. There are much researchers conducted to combat these complications. The lack of a solution to this problem affects the ultimate results of treatment and economic losses. The issue of impact by physical methods on the ureteral stent, particularly the use of extracorporeal ultrasound acoustic exposure remains, promising and poorly covered.Purpose of the study. To determine the optimal application points of extracorporeal acoustic exposure by the low-frequency ultrasonic amplitude-modulated signal on a ureteral stent in an experiment.Materials and methods. The original device was designed. The main principle of its operation is the generation of an amplitude-modulated ultrasonic signal in two modes: pulsed and permanent. A sexually mature mongrel dog was an experimental animal. The ureteral stent was placed by laparotomy and cystotomy. Intraoperatively, the emitter of the developed device was applied to the skin of the animal, according to the previously indicated topographic and anatomical landmarks. At the same time, an ultrasonic wave noise analyzer was applied through the laparotomy wound to the appropriate level of the ureter. Measurements of ultrasound intensity indicators were performed three times in two operating modes of the device.Results. Pulsed mode: for the ureteral upper third, the highest ultrasonic intensity (123.67 dB) was achieved along the posterior axillary line. For the ureteral middle third, the best ultrasound intensity (115 dB) was obtained by the posterior axillary line. For the ureteral lower third, the highest ultrasound intensity (113.67 dB) was noted along the middle axillary line.Permanent mode: the best ultrasonic intensity in the projection of the ureteral upper, middle, and lower thirds was achieved along the posterior axillary line and was 118.67 dB, 117 dB and 116.67 dB, accordingly. However, there was an excessive heat effect, manifested by hyperemia and hyperthermia of the animal's skin, fascicular muscle contractions during the instrument functioned in the permanent mode, which can potentially lead to thermal burns and intolerance to the procedure.Conclusion. The pulsed mode of the device function is most safe. The optimal application points of the instrument emitter for the ureteral upper and middle thirds is the posterior axillary line, and for the ureteral lower third is the middle axillary line.

scholarly journals An Integrated MCDM Approach to Train Derailment Risk Response Strategy Selection

Symmetry ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 47 ◽  
Author(s):  
Huafeng Zhang ◽  
Quanxin Sun
Keyword(s):  
Decision Making ◽  
Evaluation Criteria ◽  
Low Frequency ◽  
Response Strategy ◽  
Expert Advice ◽  
Rolling Stock ◽  
Economic Losses ◽  
Train Derailment ◽  
Risk Response ◽  
Risk Management Process

Train derailment can mainly cause not only economic losses in the shape of mangled rolling stock or infrastructure, but also more severely in causalities and disruptions of operations, yielding great impact on the sustainable development of railway industry. Considering various complex and symmetrical operational environments, as well as the characteristics of low frequency and high consequences of derailment accidents, risk response is undoubtedly underlined as one of the most critical components of risk management process. However, in practice, risk response does not receive enough attention in comparison with risk assessment that it lacks mature models and tools for selecting optimal strategy. This study constructs an integrated Multi Criteria Decision-Making (MCDM) model for the selection of optimum train derailment risk response strategy for the first time. In the model, decision making trial and evaluation laboratory (DEMATEL) technology is connected with analytical network process (ANP) to obtain evaluation criteria and their relative weights, and both of the two methods can deal with the complex coupling relationship between the indicators in the system. Then, technique for order performance by similarity to ideal solution (TOPSIS) is proposed to screen the optimum plan in the proposed model. Further, the Delphi method is used through the whole process to acquire expert advice. In the end, this model is used to select shunting derailment risk response strategies in Huangyangcheng station, and the final results demonstrate that this technology is simple and practical, and can provide a credible and practical tool for railway safety managers and engineers to choose the best risk response strategy.

Pipeline Leak Detection Based on Double Sensor Negative Pressure Wave

2013 ◽  
Vol 313-314 ◽  
pp. 1225-1228 ◽  
Author(s):  
Chun Xia Hou ◽  
Er Hua Zhang
Keyword(s):  
False Alarm ◽  
Negative Pressure ◽  
Pressure Wave ◽  
Detection System ◽  
Low Frequency ◽  
Leak Detection ◽  
Frequency Component ◽  
Economic Losses ◽  
Single Sensor ◽  
Negative Pressure Wave

Pipeline leak lead to huge economic losses and environmental pollution. Leak detection system based on single sensor negative pressure wave often causes false alarm. In this paper the double sensor method is adopted to exclude false alarm by determining the propagation direction of the pressure wave. In order to remove the inverse coherent interference caused by pump running, the phase difference of primary low frequency component is used to identify the sign of the time delay between the double sensors. The experiment shows the mothod is effective.

scholarly journals MODERN METHODS OF ENDOSCOPIC ENUCLEATION OF BENIGN PROSTATIC HYPERPLASIA AND PROSPECTS FOR THEIR MODIFICATION

2021 ◽  
pp. 20-29
Author(s):  
E. N. Bolgov ◽  
F. A. Sevryukov ◽  
V. V. Zhezdrin ◽  
R. N. Bobrovsky ◽  
M. A. Volodin
Keyword(s):  
Surgical Treatment ◽  
Benign Prostatic Hyperplasia ◽  
Laser Energy ◽  
Low Frequency ◽  
Complete Removal ◽  
Infectious Complications ◽  
Prostatic Hyperplasia ◽  
Anatomical Landmarks ◽  
Surgical Methods ◽  
Endoscopic Enucleation

The disadvantage of bipolar and holmium enucleation in transurethral surgery of benign prostatic hyperplasia (BPH) is the frequent postoperative urination disorders. To increase the effectiveness of surgical treatment, a modification of the surgical technique is necessary.Objective: to compare the perioperative results of endosurgical treatment of large sized BPH using transurethral bipolar (TUEB), laser (HoLEP) and modified laser prostate enucleation (HoLEP-M) methods. Patients and methods: A randomized prospective study was conducted according to the results of surgical treatment of 1104 patients with BPH with a volume of 80 to 350 cm3, divided by methods of endoscopic enucleation of the prostate. A mod-ification of the HoLEP technique was to optimize access to the surgical site with the designation of new anatomical landmarks.Results: Comparison of surgical methods showed their equivalence in the volume of removed tissue, the low frequency of hemorrhagic and infectious complications, the dynamics of urological indicators in the delayed period. TUEB has the least parameters for the time of surgical intervention (98.2 ± 2.24 min.), the vol-ume of blood loss (65.5 ± 1.83 ml), the terms of postoperative catheterization of the bladder (2.0 ± 0.32 days), and the days of hospitalization (3.2 ± 0.40 days). The safety of laser methods is higher than TUEB, during which 3.1% of closed perforations of the prostatic capsule and bladder were observed (versus 0.8-1.5% with laser methods). Modification of the HoLEP technique allows reducing the frequency of late dysuric disorders by 2-3 times, urinary incontinence by 3.4-4 times, cicatricial complications by 1.7-2 times.Conclusion: Bipolar and laser methods of transurethral enucleation of the prostate of large sizes are comparable by criteria of complete removal of prostatic tissue, effectiveness and tolerability in patients with thrombohemorrhagic risk. In terms of the frequency of intraoperative injuries, the safety of laser methods is higher due to the reduced penetrating ability of laser energy. Modification of surgical access to the prostate preserves the prostatic urethra as much as possible and is a promising measure for the prevention of late obstructive and functional complications of transurethral interventions.

scholarly journals Leptospirosis in slaughtered cows in the Triangulo Mineiro, Minas Gerais: prevalence, serological profile and renal lesions

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Geórgia Modé Magalhães ◽  
Paula Batista de Alvarenga ◽  
Alessandra Aparecida Medeiros-Ronchi ◽  
Thais de Almeida Moreira ◽  
Ligia Fernandes Gundim ◽  
...  
Keyword(s):  
High Frequency ◽  
Histopathological Examination ◽  
Low Frequency ◽  
Minas Gerais ◽  
Economic Losses ◽  
Leptospira Interrogans ◽  
Hydropic Degeneration ◽  
Renal Lesions ◽  
Antibody Titers ◽  
Complementary Examination

Leptospirosis is a zoonosis that affects several species of domestic and wild animals and is an important cause of economic losses in cattle in Brazil. In this study, we determined the prevalence of bovine leptospirosis in the Triângulo Mineiro region, Minas Gerais, Brazil, identified the most frequent serovars of Leptospira interrogans, and examine the renal pathological changes associated with the disease. Samples of blood serum and kidney fragments from 100 bovine females were collected in cattle abattoir. In the serological investigation 48% of the cows were positive. The serovars for which there were more reactive animals were Wolffi (24%), Hardjo (21%) and Hebdomadis (18%). Among the positive samples, 14/48 showed antibody titers greater than 1:100, and 70.83% of the seropositive animals responded to more than one Leptospira interrogans serovar. Only one farm did not have seropositive cows and in nine farms studied, six (66.66%) presented seropositive animals to the Hebdomadis serovar. At the histopathological examination, the most frequent microscopic lesions in positive animals were hyalinization (81.25%), congestion (81.25%) and hydropic degeneration (70.83%). However, these histopathological alterations were also found in kidneys of animals negative to serology, such as hyalinization (80.77%), congestion (48.07%) and hydropic degeneration (55.77%) and these findings are unrelated to positivity. Histopathological examination of the kidneys is not indicated to replace the serological diagnosis of leptospirosis, and may be used only as a complementary examination. Despite the low frequency of seropositive animals in the Triângulo Mineiro region, the disease is present in a large number of farms. Noteworthy is the high frequency of serovar Hebdomadis and it can be considered an emerging serovar in the region. The evaluation of the frequency of this serovar in other regions becomes important, and once verified should result in the recommendation of the inclusion of this serovar in the leptospirosis control.

scholarly journals Surgical Technique of Supine Percutaneous Nephrolithotomy in Children

2021 ◽  
Vol 30 (04) ◽  
pp. e300-e303
Author(s):  
Stefania Prada ◽  
Nicolas Fernandez ◽  
Julián Chavarriaga ◽  
Jaime Perez ◽  
Hugo López-Ramos
Keyword(s):  
Surgical Technique ◽  
Percutaneous Nephrolithotomy ◽  
Yttrium Aluminum Garnet ◽  
Guide Wire ◽  
Pediatric Population ◽  
Comparable Efficacy ◽  
Anatomical Landmarks ◽  
Ureteral Catheter ◽  
Reduce Radiation Exposure ◽  
Posterior Axillary Line

AbstractPercutaneous nephrolithotomy (PCNL) in children has become more widely used due to its high efficacy and safety and to the development of miniaturized instruments. A supine approach is promising due to advantages such as better ventilation, reproducibility, and ergonomics. The purpose of the present study is to describe our surgical technique with special considerations in the pediatric population. We used an oblique supine position supported by one silicone gel positioning pad under the hip and another under the ipsilateral flank. The anatomical landmarks used to guide the puncture were the 11th and 12th ribs, the posterior axillary line, and the iliac crest. Initially, a ureteral catheter was introduced endoscopically. A retrograde pyelography was performed to guide the puncture, which was performed using a biplanar technique. A hydrophilic guide wire was then advanced through the needle. Dilation was performed with Alken telescopic dilators until 14 Ch. Fragmentation was performed either with a 13 Ch semirigid cystoscope or a flexible ureteroscope using a holmium: yttrium aluminum garnet (Ho:Yag) laser. We left a double J catheter. Supine PCNL in the pediatric population has comparable efficacy in terms of stone free rate to that of the prone approach as well as less complications. Certain considerations in children are careful padding and placement of the patient close to the edge of the table. Puncture should be guided by ultrasound to reduce radiation exposure. Miniaturized equipment is not widely available, so adaptation of adult equipment for the pediatric population is sometimes necessary.

Single Vibroacoustic Impact Effect of Singing Bowls over the Psycho-Emotional State and Cardiovascular System Work

2021 ◽  
Vol 9 (5) ◽  
pp. 483-494
Author(s):  
Viсtor O. Oguy ◽  
Keyword(s):  
Emotional State ◽  
Low Frequency ◽  
Weighted Average ◽  
Heart Rhythm ◽  
Well Being ◽  
Power Dynamics ◽  
Orthostatic Test ◽  
Before And After ◽  
Acoustic Exposure ◽  
Singing Bowls

This article presents a two-stage study result of the author's method of vibroacoustic massage using singing bowls application. At the first stage, the effect of vibroacoustic massage single application over psycho-emotional characteristics was studied. 19 studied volunteers took part in our study. The testing results before and after exposures were compared according to the WAM (Weighted average mark), Zung, and Spielberg-Khanin tests. The study of the psycho-emotional sphere showed that after the vibroacoustic massage procedure, the indicators of "well-being" and "activity" of the WAM test significantly improved (p = 0.002). In addition, the depression level determined by the Zung test, personal anxiety indicators (p = 0.004), and situational anxiety ones (p = 0.028) decreased. At the second stage, 62 volunteers were divided into two groups. The first group underwent a vibroacoustic massage session according to the patented author's method. The second group received only acoustic exposure using only singing bowls. Differences in the Kerdo index were revealed in the dynamics, and in the first group, the changes were less significant than in the second one. Changes in heart rate variability characteristics for both groups were similar: there was an increase in parasympathetic influences at rest and during the orthostatic test (increased levels of RMSSD (Root Mean Square of Successive Differences), NN50, pNN50) and a decrease in sympathetic effects at rest and their slight increase with orthostatic loading (TINN, RR triangular index). The dynamics were more significant in the first group that received a vibroacoustic massage session. When assessing changes in the neurovegetative regulation levels activity of the heart rhythm, the main difference was associated with very low-frequency waves power dynamics during the orthostatic test. Thus, vibroacoustic massage using singing bowls improves the psycho-emotional state, reduces depression and anxiety, and increases Parasympaticus (autonomic nervous system) activity.

Experimental Study on Secondary Effluent Disinfection with Ultrasound and Chlorine

2011 ◽  
Vol 383-390 ◽  
pp. 3786-3791
Author(s):  
Zi Fu Li ◽  
Xin Zhao ◽  
Fu Rong Deng ◽  
Xin Jin ◽  
Hao Wu
Keyword(s):  
Contact Time ◽  
Irradiation Time ◽  
Low Frequency ◽  
Coliform Bacteria ◽  
Secondary Effluent ◽  
Chlorine Disinfection ◽  
Low Frequency Ultrasound ◽  
Ultrasound Intensity ◽  
High Power Consumption ◽  
Economic Considerations

Ultrasonic disinfection is safe and effective, but requires high power consumption. For economic considerations, ultrasound and chlorine can be combined to promote a wider range of applications. In this paper, we investigated the disinfection effect of secondary effluent with low-frequency ultrasound and sodium hypochlorite. The optimal conditions were determined by changing the ultrasound intensity, exposure time, chlorine dosage, and chlorine contact time. The results showed that ultrasound can significantly enhance the effects of chlorine disinfection. When the coliform bacteria is 106~107CFU/L, the dosage of chlorine at 4~6mg/l can meet the national discharge standard (less than 104 CFU /L). However, the chlorine dosage can be further reduced to 1~2mg/l if we add 30 s of ultrasonic radiation, thereby reducing the disinfection by-products. Orthogonal experimental results show that the relative importance of the disinfection factors: chlorine dosage> ultrasonic irradiation time >chlorine contact time> ultrasound intensity.

scholarly journals Frequency of antibodies to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burdgorferi in cattle from the northeastern region of the state of Pará, Brazil

2008 ◽  
Vol 17 (2) ◽  
pp. 105-109 ◽  
Author(s):  
Daniel S. Guedes Junior ◽  
Flábio R. Araújo ◽  
Fábio J.M. Silva ◽  
Charles P. Rangel ◽  
José D. Barbosa Neto ◽  
...  
Keyword(s):  
Low Frequency ◽  
Anaplasma Marginale ◽  
High Rate ◽  
Economic Losses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Lower Sensitivity ◽  
Trypanosoma Vivax ◽  
Babesia Bigemina ◽  
Adult Cattle ◽  
Northeastern Region

Babesiosis, anaplasmosis, and trypanosomosis are relevant diseases, potentially causing morbidity in cattle, leading to economic losses. Borreliosis is import as a potential zoonosis. The objective of this study was to determine, by indirect enzyme-linked immunosorbent assay (ELISA), the frequency of seropositive cattle to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burgdorferi in cattle from the Northeastern region of Pará, Brazil. Sera samples from 246 female adult cattle from municipalities of Castanhal and São Miguel do Guamá were used. Crude antigens ELISAs were used to detect antibodies to all agents, except to A. marginale, to which an indirect ELISA with recombinant major surface 1a protein (MSP1a) antigen was used. Overall frequencies of seropositive animals were: B. bigemina - 99.2%; B. bovis - 98.8%; A. marginale - 68.3%; T. vivax - 93.1% and B. burgdorferi - 54.9%. The frequencies of seropositive cattle to B. bovis and B. bigemina suggest a high rate of transmission of these organisms by tick in the studied region, which can be classified as enzootically stable to these hemoprotozoans. The low frequency of seropositive cattle to A. marginale may be attributed to a lower sensitivity of the recombinant antigen ELISA utilized or a distinct rate of inoculation of this rickettsia by ticks, as compared with Babesia sp. transmission. The high frequency of seropositive cattle to T. vivax indicates that this hemoprotozoan is prevalent in herds from the Northeastern region of Pará. The rate of animal that showed homologues antibodies to B. burgdorferi indicates the presence of the tickborne spirochaetal agent in the cattle population in the studied region.

Development of Frost and Thaw Depth Predictors for Decision Making about Variable Load Restrictions

2008 ◽  
Vol 2053 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Sarah Baïz ◽  
Susan L. Tighe ◽  
Carl T. Haas ◽  
Brian Mills ◽  
Max Perchanok
Keyword(s):  
Low Frequency ◽  
Weather Conditions ◽  
Economic Losses ◽  
Variable Load ◽  
Northern Ontario ◽  
Traffic Loading ◽  
Low Volume Roads ◽  
Calculation Algorithms ◽  
Frost Depth ◽  
Thaw Depth

Low-volume roads covering the northern part of Ontario, Canada, are a critical asset; they enable the movement of goods from remote resource areas to markets. However, challenged by a combination of heavy, low-frequency traffic loading and a high number of freeze-thaw cycles for which most have not been structurally designed, such highways often experience seasonal damage and premature traffic-induced deterioration. To mitigate these impacts, the Ontario Ministry of Transportation and other departments of transportation place seasonal load restrictions (SLRs) every year during the spring thaw. For economic reasons, the duration of SLRs is usually fixed in advance and is not applied according to conditions in a particular year. Rigidity in the schedule may result in economic losses because the payload can be unnecessarily restricted or pavement deterioration can occur. The latest attempts to address this issue include the use of climatic and deflection data to assess the bearing capacity of the roadway better. The use of frost and thaw depth predictors to track spring thaw weakening could improve the scheduling of load restrictions. On the basis of field data captured in Northern Ontario, a good correlation was found between the amount of frost depth in the pavement and weather conditions monitored by road weather information systems. An empirical methodology for site-specific calibration of the predictors is proposed, and the steps toward its development and the calculation algorithms are detailed.

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