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821.
822.
Ultrasonic mate calling in the lesser wax moth 总被引:5,自引:0,他引:5
ABSTRACT. The lesser wax moth, Achroia grisella (Fabricius) (Pyralidae: Galleriinae), uses an altrasonic communication system for mate calling The male produces a 100 kHz sound by striking its tegula with the forewing. This calling sound induces virgin females to orient toward males. Although the pheromone released from the male's wing glands may stimulate kinesis in females, it does not elicit orientation. Female moths are attracted toward synthetic 40 and 72 kHz sounds which simulate the pulse length and repetition rate of the male's calling signal. 相似文献
823.
Armin Hochreiner Thomas Berer Hubert Grün Michael Leitner Peter Burgholzer 《Journal of biophotonics》2012,5(7):508-517
In this paper we report on remote three‐dimensional photoacoustic imaging without the need for a coupling agent or other aids (e.g. detector foils) by utilizing a two‐wave mixing interferometer (TWMI). In this technique the beams coming from sample and reference are brought to interfere in a Bi12SiO20 photorefractive crystal (PRC). Such a setup allows the measurement of ultrasonic displacements on rough sample surfaces. After data acquisition the initial pressure distribution is reconstructed by a Fourier domain synthetic aperture focusing technique (FSAFT). We present three‐dimensional imaging of a hair ribbon phantom, on biological samples with embedded artificial blood vessels or pig bristles, and measurements on a human forearm in‐vivo. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
824.
The maternal portion of the bovine placenta receives blood mainly from the uterine arteries (AUT) and the fetal portion from the umbilical arteries (AUM). Placental perfusion is crucial for fetal development and undergoes adaptive changes during pregnancy according to the fetal requirements. One goal of this study was to investigate changes in Doppler sonographic measurements of blood vessels that supply blood to the placenta in cows during the last 4 weeks of pregnancy. Another goal was to examine how these measurements are affected by three drugs commonly used in cows at the time of parturition. Nine cows underwent Doppler sonographic examination of the AUT ipsilateral and contralateral to the pregnant horn and one AUM three times per week during the last 4 weeks of gestation. This was followed by the randomized administration of one of the three following experimental drugs per day: isoxsuprine (200 mg/cow, iv), xylazine (2 mg/100 kg, iv), and lidocaine for epidural anesthesia (100 mg/cow). Doppler sonographic examination was repeated 30 minutes after medication. Maternal pulse rate increased during the study period (P < 0.001), and the diameter of the contralateral AUT was smaller in the last week before birth than in the two preceding weeks. The resistance index (RI) of the ipsilateral AUT was smaller in the last week than in the first 2 weeks of the study period. Uterine blood flow volume increased after isoxsuprine by 5% and after epidural anesthesia by 6% (both P ≤ 0.05) and decreased after xylazine by 10% (P < 0.001). Isoxsuprine was the only drug that elevated the blood flow volume in the AUM (P ≤ 0.05). Xylazine increased the RI of both AUT (both P < 0.001) and significantly reduced maternal and fetal pulse frequencies, whereas isoxsuprine significantly reduced the RI of both AUT and the AUM and increased maternal and fetal pulse frequencies. The results reported that Doppler sonographic measurements of uterine and AUM change little in the last month of pregnancy in the cow. Isoxsuprine and epidural anesthesia with lidocaine have the potential to improve uterine perfusion. 相似文献
825.
《Current biology : CB》2023,33(15):3257-3264.e4
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826.
《Endocrinología y nutrición》2014,61(6):329-334
Appearance of a thyroid nodule has become a daily occurrence in clinical practice. Adequate thyroid nodule assessment requires several diagnostic tests and multiple medical appointments, which results in a substantial delay in diagnosis. Implementation of a high-resolution thyroid nodule clinic largely avoids these drawbacks by condensing in a single appointment all tests required for adequate evaluation of thyroid nodule. This paper reviews the diagnostic and functional structure of a high-resolution thyroid nodule clinic. 相似文献
827.
Three different methods to standardize biofilm removal for in situ sanitary control of closed surfaces in the food industry have been developed and compared, i.e. sonication, enzymatic treatment and a combined treatment which involved the application of ultrasound to enzyme preparations. The biofilm studied was an Escherichia coli model biofilm, made with milk on stainless steel sheets. Plate counting and epifluorescence microscopy were used to assess the efficiency of each treatment. The results are expressed in percentages, 100% denoting total removal, obtained with a flat ultrasonic transducer (T1) developed and presented in a previous study. The application of ultrasound by a patented curved transducer, T2 (10 s, 40 kHz), specifically devised for closed surfaces, was not sufficient to completely remove the biofilm (30 ± 7%). This biofilm was dislodged by two proteolytic enzyme preparations tested by immersion, viz. a 15‐min application of protease (84±1%) and a 30‐min trypsin application (95±8%). Using a combined treatment, the results showed a synergism between ultrasonic waves and proteolytic or glycolytic enzyme preparations, with removal of a significant amount of biofilm, i.e. 61–96% depending on the conditions tested, i.e. two to three times greater compared to sonication alone (30%). This application was in agreement with an industrial control, i.e. a good reproducible recovery of the biofilm in 10 s compared with 30 or 15 min with the enzyme alone. 相似文献
828.
《Indian pacing and electrophysiology journal》2023,23(1):23-26
A young-male underwent radiofrequency (RF) ablation of ventricular premature contractions (VPCs) of over 30,000/day and the morphology exhibited left bundle branch block and a superior axis, which indicated the VPCs originated from the inferior portion of the right ventricle (RV). While the PENTARAY catheter was placed under the tricuspid valve (TV), the earliest potential, which preceded the QRS onset by 34 ms, was recorded. Pace mapping there presented a very similar QRS morphology to the target VPC. However, the radiofrequency (RF)-catheter could not be placed under the TV even when a deflectable sheath was used, because the deflectable curve of the RF-catheter was larger than that of the PENTARAY. An over-the-vale RF application was not effective, so the trans-jugular approach with a deflectable sheath was indicated. The tip of the sheath was placed at a higher portion of the RV cavity to maintain an adequate distance for the RF-catheter tip to be deflected and placed under the TV. With this maneuver, the tip of the RF-catheter was successfully placed under the TV, which was confirmed by intracardiac ultrasound. Small atrial potentials and larger ventricular potentials could be recorded from the distal tip of the RF-catheter, which might indicate that the tip was placed at the TV annulus. An RF application at that site permanently abolished the VPC. Placing the tip of the RF-catheter under the TV by the femoral approach is very difficult in some cases. The trans-jugular approach with a deflectable sheath is one option for arrhythmias from the TV. 相似文献
829.
Herein, we make an effort to enhance the antimicrobial activity of levofloxacin (LVX) antibiotic via conjugation to a cell‐penetrating peptide (CPP) including Cys‐Gly‐Ala‐Phe‐Pro‐His‐Arg. For this purpose, cysteine is used as a linker between the LVX and CPP chain, and two heterogeneous nanoscale catalytic systems are employed as the substantial alternatives for traditional peptide coupling reagents like N,N,N′,N′‐tetramethyl‐O‐(benzotriazol‐1‐yl)uronium tetrafluoroborate (TBTU). Briefly, it has been found out that the antimicrobial potency of the synthesized CPP‐LVX conjugate (on the gram‐positive and gram‐negative bacteria) is noticeably enhanced (~20% more). It has been revealed via zone of inhibition (ZOI) and optical density (OD) evaluations. As a convenient method for making this type of the effective conjugations, ultrasound waves (with a specific frequency and power density) activate the catalytic sites of the heterogeneous nanoparticles. Through this synergistic effect, peptide/amide bond is formed during a short time (10 min), and high reaction yield (>90%) is obtained under mild conditions. Moreover, as a simple purification process, the catalyst nanoparticles are collected and separated through their high magnetic property. 相似文献