Functional Anatomy of the Female Pelvic Floor

The anatomic structures in the female that prevent incontinence and genital organ prolapse on increases in abdominal pressure during daily activities include sphincteric and supportive systems. In the urethra, the action of the vesical neck and urethral sphincteric mechanisms maintains urethral closure pressure above bladder pressure. Decreases in the number of striated muscle fibers of the sphincter occur with age and parity. A supportive hammock under the urethra and vesical neck provides a firm backstop against which the urethra is compressed during increases in abdominal pressure to maintain urethral closure pressures above the rapidly increasing bladder pressure. This supporting layer consists of the anterior vaginal wall and the connective tissue that attaches it to the pelvic bones through the pubovaginal portion of the levator ani muscle, and the uterosacral and cardinal ligaments comprising the tendinous arch of the pelvic fascia. At rest the levator ani maintains closure of the urogenital hiatus. They are additionally recruited to maintain hiatal closure in the face of inertial loads related to visceral accelerations as well as abdominal pressurization in daily activities involving recruitment of the abdominal wall musculature and diaphragm. Vaginal birth is associated with an increased risk of levator ani defects, as well as genital organ prolapse and urinary incontinence. Computer models indicate that vaginal birth places the levator ani under tissue stretch ratios of up to 3.3 and the pudendal nerve under strains of up to 33%, respectively. Research is needed to better identify the pathomechanics of these conditions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72597/1/annals.1389.034.pd

Transport of quantum states of periodically driven systems

We discuss the transport of quantum states on quasi-energy surfaces of periodically driven systems and establish their non-trivial structure. The latter is shown to be caused by diabatic transitions at lines of narrow avoided crossings. Some experimental consequences pertaining to adiabatic transport and Landau-Zener transitions among Floquet states are briefly sketched.On traite des holonomies quantiques sur des surfaces de quasi-énergie de systèmes soumis à une excitation périodique, et on établit leur topologie globale non triviale. On montre que cette dernière est causée par des transitions diabatiques entre niveaux au passage d'anticroisements serrés. On donne brièvement quelques conséquences expérimentales concernant le transport adiabatique et les transitions de Landau-Zener entre états de Floquet

Imaging characteristics of episiotomy scars on translabial ultrasound : an observational study

Introduction: Episiotomy has been purported to protect the anal sphincter from injury; efficacy is, however, disputed. Correct execution of episiotomy may have substantial implications. We aimed to describe the characteristics of episiotomy scars on translabial ultrasound (TLUS). Methods: In this retrospective observational study involving women after repair of obstetric anal sphincter injuries, 76 women with a history of episiotomy were analyzed. Episiotomy scars were assessed on tomographic ultrasound in the transverse plane using volumes acquired on pelvic floor muscle contraction. We measured scar length, depth, and angle relative to a vertical reference line. Episiotomy scars were described as 1) ipsilateral if they started on the same side as the direction of the episiotomy, 2) contralateral if on the opposite side, and 3) mediolateral if the scar began in the midline. Results: The mean scar angle was 50.5° (SD 14°; range 14.4°–79.3°) while mean scar length was 14.2 mm (SD 4.5; range 5.7–27.5 mm) and depth was 8.4 mm (SD 2.8, range 3.1–18.2 mm). Sixteen (21%) scars were located mediolateral while 32 (42%) were ipsilateral. In 28 (37%) women, the starting point of the episiotomy was located contralateral to the direction of the episiotomy. Conclusion: In this pilot series, the mean angle of episiotomy scars was within the safe zone of 40° to 60°, however, in one-third of cases the cut may have been initially directed toward the sphincter, not away from it. This observation suggests that not all episiotomies are performed optimally

Stress urinary incontinence after transobturator mesh for cystocele repair

Cystocele repair can lead to de novo stress urinary incontinence (SUI) or exacerbate pre-existing SUI. This study was designed to determine the effect of cystocele repair by transobturator mesh on SUI. In a retrospective observational study, we saw 93 patients after a transobturator mesh procedure. Of those, 57 women had not undergone a concomitant anti-incontinence procedure. We analyzed their clinical data and ultrasound datasets. At a median follow-up of 9 months, 21 of 24 preoperatively stress incontinent women reported cure/improvement, one patient reported worsened SUI. Seven of 33 preoperatively continent women complained of de novo SUI. There is a net positive effect on SUI (McNemar χ2 exact test p = 0.013) after transobturator mesh. A narrower gap between symphysis pubis and mesh was associated with a positive outcome (p = 0.015 on ANOVA). Transobturator mesh for cystocele repair appears to have a net positive effect on SUI

Selective excitation of molecular vibrations by interference of Floquet states

SIGLEAvailable from TIB Hannover: RO 5080(90-07) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

The role of avoided crossings in the dynamics of strong laser field-matter interactions

SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

On the classical dynamics of strongly driven anharmonic oscillators

SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman