|
|
|
BRL Abstracts Database |
|
Your search for ultrasound produced 3296 results. Page 104 out of 330
| Title |
Effects of highly dosed ultrasound on the growing rabbit's larynx Scanning electron microscopic and reflecting light microscopic findings. |
| Author |
Karduck A, Richter HG. |
| Journal |
Arch Otorhinolaryngol |
| Volume |
|
| Year |
1975 |
| Abstract |
The morphologically recognizable effects of highly dosed ultrasound application on the growing rabbit's larynx (5 Watt/cm2 for 10 min) were studied by means of scanning electron microscopic (SEM) and reflecting light microscopic (RLM) methods. It could be shown that the area of cartilaginous necrosis corresponded exactly to the location of ultrasound application and was sharply limited by the normal cartilage. After a survival period of six weeks, areas of chondroneogenesis became visible on the endolaryngeal perichondrium. After a survival period.of twelve weeks, an outer zone of cartilaginous necrosis was still to be seen. Connective tissue directly affected by ultrasound and the endolaryngeal muscles did not show any retarded damage. The results of our experiments permit to state that highly dose ultrasound application on the cartilaginous framework leads to a growth retardation with a subsequent alteration in form and shape. |
| Title |
Effects of in utero ultrasound exposure on the development of the fetal mouse testis. |
| Author |
Carnes KI, Hess RA, Dunn F. |
| Journal |
Biol Reprod |
| Volume |
|
| Year |
1991 |
| Abstract |
The effect on the developing fetal testis of in utero exposure to 1-MHz, continuous-wave ultrasound in the spatial peak, temporal average intensity range 0.5-10 W/cm2 for durations of 400-30 sec on Day 9, 12, or 15 of gestation was determined. Results show that two subtle, yet potentially deleterious, effects occurred: a reduction in the Sertoli cell population and an apparent delay in the cessation of gonocyte mitosis. An increase was also seen in the number of fetal resorptions and stillborn pups per number of implantation sites in the exposed specimens as compared to the sham and cage controls. Because the reduction in testis weight was proportional to decreased body weight and because there was no difference in Sertoli cell numbers due to day of treatment, the testicular effects may reflect a generalized delay in growth. Whether this effect of ultrasound on fetal testis will be translated into an equal reduction in germ cell numbers in the adult testis remains to be determined. |
| Title |
Effects of in vivo diagnostic ultrasound on SCE frequency in cultured amniocytes. [letter] |
| Author |
Mitter NS, Chudley AE. |
| Journal |
Am J Med Genet |
| Volume |
|
| Year |
1982 |
| Abstract |
No abstract available. |
| Title |
Effects of intense noncavitating ultrasound on selected enzymes. |
| Author |
Macleod RM, Dunn F. |
| Journal |
J Acoust Soc Am |
| Volume |
|
| Year |
1968 |
| Abstract |
The denaturation of enzymes in solution by cavitating ultrasound has been reported previously. This report presents the results of an extensive study of the effects of noncavitating ultrasound on solutions of alpha-chymotrypsin, trypsin, aldolase, lactate dehydrogenase, and ribonuclease. In one set of experiments, the solutions were irradiated and then analyzed to determine the effects on the physical and chemical properties of the enzyme molecules. Irradiations were carried out at different pH values and temperatures using 1-MHz ultrasound at an intensity of 75 W/cm(^2), 10-min continuous exposure, and 11-MHz ultrasound at an intensity of 1000 W/cm(^2), 2000 0.1-sec pulses. Analytical procedures employed included measurements of enzyme activity, specific optical rotation, uv absorption spectrum, and sedimentation coefficient. In a second set of experiments, enzyme-catalyzed reactions were irradiated with ultrasound and simultaneously monitored spectrophotometrically. Ultrasound in the intensity range 0.5-35 W/cm(^2) at the frequencies 1, 9, and 27 MHz were employed with the temperature and pH held constant. Comparison of the results of this study with those from studies employing cavitation shows that cavitation is a necessary condition for ultrasonic denaturation of the five enzymes of this study. |
| Title |
Effects of intense noncavitating ultrasound on selected enzymes. |
| Author |
Dunn F, Macleod RM. |
| Journal |
J Acoust Soc Am |
| Volume |
|
| Year |
1968 |
| Abstract |
The denaturation of enzymes in solution by cavitating ultrasound has been reported previously. This report presents the results of an extensive study of the effects of noncavitating ultrasound on solutions of alpha-chymotrypsin, trypsin, aldolase, lactate dehydrogenase, and ribonuclease. In one set of experiments, the solutions were irradiated and then analyzed to determine the effects on the physical and chemical properties of the enzyme molecules. Irradiations were carried out at different pH values and temperatures using 1-MHz ultrasound at an intensity of 75 W/cm2, 10-min continuous exposure, and 11-MHz ultrasound at an intensity of 1000 W/cm2, 2000 0.1-sec pulses. Analytical procedures employed included measurements of enzyme activity, specific optical rotation, uv absorption spectrum, and sedimentation coefficient. In a second set of experiments, enzyme-catalyzed reactions were irradiated with ultrasound and simultaneously monitored spectrophotometrically. Ultrasound in the intensity range 0.5–35 W/cm2 at the frequencies 1, 9, and 27 MHz were employed with the temperature and pH held constant. Comparison of the results of this study with those from studies employing cavitation shows that cavitation is a necessary condition for ultrasonic denaturation of the five enzymes of this study. |
| Title |
Effects of lithotripter fields on biological tissues. |
| Author |
Dalecki D. |
| Journal |
J Acoust Soc Am |
| Volume |
|
| Year |
1998 |
| Abstract |
Biological effects resulting from exposure to lithotripter fields include hemorrhage in soft tissues, such as the kidney, lung, and intestine, the production of premature cardiac contractions, malformations in the chicken embryo, and killing of Drosophila larvae. Pulsed ultrasound can produce similar bioeffects at comparable pressure thresholds. Tissues that contain gas bodies, either naturally or after the addition of ultrasound contrast agents, are particularly susceptible to damage from low‐amplitude lithotripter fields. Lung and intestine contain gas naturally and are hemorrhaged by exposure to lithotripter fields on the order of 1 MPa. After the introduction of an ultrasound contrast agent into the vasculature, many organs and tissues, such as the bladder, kidney, fat, muscle, and mesentery, show extensive hemorrhage after exposure to lithotripter pressures less than 2 MPa. Tissues near developing bone are also selectively susceptible to damage from exposure to low‐amplitude lithotripter fields. The thresholds for hemorrhage in tissues near developing bone, such as the fetal head, limbs, and ribs, are all less than 1 MPa for exposures with a piezoelectric lithotripter. Cavitation and purely mechanical forces have been investigated as possible mechanisms for these biological effects of lithotripter fields. |
| Title |
Effects of lithotripter fields on development of chick embryos. |
| Author |
Hartman C, Cox CA, Brewer L, Child SZ, Cox CF, Carstensen EL. |
| Journal |
Ultrasound Med Biol |
| Volume |
|
| Year |
1990 |
| Abstract |
Chick embryos at 72 h incubation were subjected to three double shock waves.from a Wolf Model 2137.50 Electrohydraulic Lithotripter. The pressure.amplitude at the embryo was adjusted by variation of the distance from the source.to the embryo. After a total of 120 h of incubation, they were assessed for.developmental abnormalities. Early deaths, delayed deaths and malformations.were all significantly increased at pressures of 10 MPa with suggestions of.possible effects at lower pressure levels. |
| Title |
Effects of localized ultrasonic irradiation on Pisum sativum roots. |
| Author |
Law WK, Carstensen EL, Miller MW. |
| Journal |
Environ Exp Bot |
| Volume |
|
| Year |
1978 |
| Abstract |
Histological studies on pea roots sonicated by a broad beam of ultrasound indicated that most of the damage occurs in the elongation region. There is little microscopic evidence of cell destruction in the meristem, and yet this region of dividing cells shows a marked cytokinetic response to sonication. Indirect effects of ultrasound were therefore suspected to exist. By using focused ultrasound to irradiate root segments as small as 1 mm2, and then observing changes in growth and mitotic index outside the region of sonication, the existence of indirect effects of ultrasound was established. Histological observations on sections of treated roots indicated necrotic nuclei within and without the region of sonication. |
| Title |
Effects of low-intensity ultrasound on the central nervous system of primates. |
| Author |
Hu JH, Ulrich WD. |
| Journal |
Aviat Space Environ Med |
| Volume |
|
| Year |
1976 |
| Abstract |
The brains of anesthesized squirrel monkeys were exposed to 2.25 to 5 MHz ultrasound at low intensities (average power from 3 mW/cm2 to 0.9 W/cm2). The exposure produced evoked potentials recorded by EEG electrodes chronically implanted in the midline parietal region. Computer analysis of the waveforms showed that ultrasound produced a transient upward shift in both the peak frequency and in its amplitude. Complete adaptation occurred with 3 min of continuous exposure to either CW or pulsed irradiation. |
| Title |
Effects of low-intensity ultrasound on viscous properties of Helodea cells. |
| Author |
Johnsson A, Lindvall A |
| Journal |
Naturwissenschaften |
| Volume |
|
| Year |
1969 |
| Abstract |
No abstract available |
Page 1
| 2
| 3
| 4
| 5
| 6
| 7
| 8
| 9
| 10
| 11
| 12
| 13
| 14
| 15
| 16
| 17
| 18
| 19
| 20
| 21
| 22
| 23
| 24
| 25
| 26
| 27
| 28
| 29
| 30
| 31
| 32
| 33
| 34
| 35
| 36
| 37
| 38
| 39
| 40
| 41
| 42
| 43
| 44
| 45
| 46
| 47
| 48
| 49
| 50
| 51
| 52
| 53
| 54
| 55
| 56
| 57
| 58
| 59
| 60
| 61
| 62
| 63
| 64
| 65
| 66
| 67
| 68
| 69
| 70
| 71
| 72
| 73
| 74
| 75
| 76
| 77
| 78
| 79
| 80
| 81
| 82
| 83
| 84
| 85
| 86
| 87
| 88
| 89
| 90
| 91
| 92
| 93
| 94
| 95
| 96
| 97
| 98
| 99
| 100
| 101
| 102
| 103
| 104
| 105
| 106
| 107
| 108
| 109
| 110
| 111
| 112
| 113
| 114
| 115
| 116
| 117
| 118
| 119
| 120
| 121
| 122
| 123
| 124
| 125
| 126
| 127
| 128
| 129
| 130
| 131
| 132
| 133
| 134
| 135
| 136
| 137
| 138
| 139
| 140
| 141
| 142
| 143
| 144
| 145
| 146
| 147
| 148
| 149
| 150
| 151
| 152
| 153
| 154
| 155
| 156
| 157
| 158
| 159
| 160
| 161
| 162
| 163
| 164
| 165
| 166
| 167
| 168
| 169
| 170
| 171
| 172
| 173
| 174
| 175
| 176
| 177
| 178
| 179
| 180
| 181
| 182
| 183
| 184
| 185
| 186
| 187
| 188
| 189
| 190
| 191
| 192
| 193
| 194
| 195
| 196
| 197
| 198
| 199
| 200
| 201
| 202
| 203
| 204
| 205
| 206
| 207
| 208
| 209
| 210
| 211
| 212
| 213
| 214
| 215
| 216
| 217
| 218
| 219
| 220
| 221
| 222
| 223
| 224
| 225
| 226
| 227
| 228
| 229
| 230
| 231
| 232
| 233
| 234
| 235
| 236
| 237
| 238
| 239
| 240
| 241
| 242
| 243
| 244
| 245
| 246
| 247
| 248
| 249
| 250
| 251
| 252
| 253
| 254
| 255
| 256
| 257
| 258
| 259
| 260
| 261
| 262
| 263
| 264
| 265
| 266
| 267
| 268
| 269
| 270
| 271
| 272
| 273
| 274
| 275
| 276
| 277
| 278
| 279
| 280
| 281
| 282
| 283
| 284
| 285
| 286
| 287
| 288
| 289
| 290
| 291
| 292
| 293
| 294
| 295
| 296
| 297
| 298
| 299
| 300
| 301
| 302
| 303
| 304
| 305
| 306
| 307
| 308
| 309
| 310
| 311
| 312
| 313
| 314
| 315
| 316
| 317
| 318
| 319
| 320
| 321
| 322
| 323
| 324
| 325
| 326
| 327
| 328
| 329
| 330
|
|
|
|
