Prominence of Terahertz Acoustic Surface Plasmon Excitation in Gas-Surface Interaction with Metals.

The current understanding of the dynamics of gas-surface interactions is that all of the energy lost in the collision is transferred to vibrations of the target. Electronic excitations were shown to play a marginal role except for cases in which the impinging particles have energies of several electronvolts. Here we show that this picture does not hold for metal surfaces supporting acoustic surface plasmons. Such loss, dressed with a vibronic structure, is shown to make up a prominent energy transfer route down to the terahertz region for Ne atoms scattering off Cu(111) and is expected to dominate for most metals. This mechanism determines, e.g., the drag force acting on telecommunication satellites, which are typically gold-plated to reduce overheating by sunshine. The electronic excitations can be unambiguously discerned from the vibrational ones under mild hyperthermal impact conditions.

Sexual function after vaginal erbium laser: the results of a large, multicentric, prospective study.

The aim of this multicentric, prospective study was to evaluate the effects of vaginal erbium laser (VEL-SMOOTH®) on sexual function in postmenopausal women suffering from the genitourinary syndrome of menopause (GSM). This study was performed on an outpatient basis without anesthesia or drug use before or after the intervention, using an erbium laser (XS Fotona Smooth®, Fotona, Ljubljana, Slovenia) in 1081 postmenopausal women (age 54.3 ± 3.9 years) treated with up to three laser applications every 30 days. Patients were assessed using the Female Sexual Function Index (FSFI) and the Female Sexual Distress Scale-Revised (FSDS-R). No adverse events were recorded during the study. The FSDS-R scores (n = 554), from basal values of 25.5 ± 3.5, were 11.5 ± 3.0, 10.5 ± 3.5 and 11.5 ± 3.5 at the 4-, 12- and 24-week follow-ups, respectively (p < 0.01 vs. corresponding basal values). Individual FSFI domain scores (n = 569) significantly (p < 0.001) increased after VEL-SMOOTH® treatment and remained significantly higher up to the 24th week after the end of treatment. The total scores, from basal values of 15.5 ± 1.5, were 27.5 ± 2.5, 27.6 ± 2.7and 27.0 ± 3.5 at the 4-, 12- and 24-week follow-ups, respectively (p < 0.01 vs. corresponding basal values). Albeit not randomized, this large, prospective study shows that VEL-SMOOTH® treatment may improve sexual function in postmenopausal women suffering from GSM.

Velocity distributions in microskimmer supersonic expansion helium beams: High precision measurements and modeling.

Supersonic molecular beams are used in many applications ranging from spectroscopy and matter wave optics to surface science. The experimental setup typically includes a conically shaped, collimating aperture, the skimmer. It has been reported that microskimmers with diameters below 10 µm produce beams with significantly broader velocity distributions (smaller speed ratios) than larger skimmers. Various explanations for this phenomenon have been proposed, but up till now, only a limited amount of data has been available. Here we present a systematic study of the velocity distribution in microskimmer supersonic expansion helium beams. We compare a 4 µm diameter skimmer with a 390 µm diameter skimmer for room temperature and cooled beams in the pressure range 11-181 bars. Our measurements show that for properly aligned skimmers, the only difference is that the most probable velocity for a given pressure and temperature is slightly lower for a microskimmed beam. We ascribed this to the comparatively narrow and long geometry of the microskimmers which can lead to local pressure variations along the skimmer channel. We compare our measurements to a model for the supersonic expansion and obtain good agreement between the experiments and simulations.

A modified time-of-flight method for precise determination of high speed ratios in molecular beams.

Time-of-flight (TOF) is a standard experimental technique for determining, among others, the speed ratio S (velocity spread) of a molecular beam. The speed ratio is a measure for the monochromaticity of the beam and an accurate determination of S is crucial for various applications, for example, for characterising chromatic aberrations in focussing experiments related to helium microscopy or for precise measurements of surface phonons and surface structures in molecular beam scattering experiments. For both of these applications, it is desirable to have as high a speed ratio as possible. Molecular beam TOF measurements are typically performed by chopping the beam using a rotating chopper with one or more slit openings. The TOF spectra are evaluated using a standard deconvolution method. However, for higher speed ratios, this method is very sensitive to errors related to the determination of the slit width and the beam diameter. The exact sensitivity depends on the beam diameter, the number of slits, the chopper radius, and the chopper rotation frequency. We present a modified method suitable for the evaluation of TOF measurements of high speed ratio beams. The modified method is based on a systematic variation of the chopper convolution parameters so that a set of independent measurements that can be fitted with an appropriate function are obtained. We show that with this modified method, it is possible to reduce the error by typically one order of magnitude compared to the standard method.

Rationale and design for the Vaginal Erbium Laser Academy Study (VELAS): an international multicenter observational study on genitourinary syndrome of menopause and stress urinary incontinence.

The genitourinary syndrome of menopause (GSM) and stress urinary incontinence (SUI) are common clinical challenges for women's health and quality of life. The laser treatment and particularly the vaginal erbium laser (VEL) may provide a new non-invasive treatment for both GSM and SUI. However, the estimation of the ultimate results of different laser treatments may be altered by different issues, such as patient selection, concomitant treatments, and long-term effect of vaginal laser thermotherapy. In the present paper, we present the protocol for a large multicenter study on the evaluation of the efficacy and safety of VEL for the treatment of GSM and SUI, the Vaginal Erbium Laser Academy Study (VELAS). This study will evaluate the effects of three laser applications in 1500 postmenopausal women. Subjective and objective symptoms will be evaluated prior to the first laser treatment with follow-up visits after 4 weeks from the last laser application, and subsequently after every 3 months for 1 year. Findings from the VELAS have the potential to affect clinical care practice and health decisions for millions of women world-wide for a non-hormonal treatment for GSM and a non-invasive treatment of SUI.

Two dimensional imaging of the virtual source of a supersonic beam: helium at 125 K.

Here we present the first two-dimensional images of the virtual source of a supersonic helium expansion. The images were obtained using a free-standing Fresnel zone plate with an outermost zone width of 50 nm as imaging lens and a beam cooled to around 125 K. The nozzle diameter was 10 µm. The virtual source diameter was found to increase with stagnation pressure from 140 ± 30 µm at po = 21 bar up to 270 ± 25 µm at po = 101 bar. The experimental results are compared to a theoretical model based on the solution of the Boltzmann equation by the method of moments. The quantum mechanical cross sections used in the model have been calculated for the Lennard-Jones (LJ) and the Hurly-Moldover (HM) potentials. By using a scaling of the perpendicular temperature that parametrizes the perpendicular velocity distribution based on a continuum expansion approach, the LJ potential shows a good overall agreement with the experiment. However, at higher pressures the data points lie in between the two theoretical curves and the slope of the trend is more similar to the HM curve. Real gas corrections to enthalpy are considered but they affect the results less than the experimental errors.

A free jet (supersonic), molecular beam source with automatized, 50 nm precision nozzle-skimmer positioning.

Low energy (thermal) free jet (supersonic) molecular beams are used in a range of applications from surface science and surface deposition to quantum coherence and gas kinetics experiments. A free jet molecular beam is created by a gas expansion from a high pressure reservoir through a small aperture (nozzle). The nozzle typically has a diameter of 2-20 µm. The central part of the beam is selected using a skimmer, typically up to 500 µm in diameter. Recent years have seen the introduction of highly spatially confined beam sources based on micrometer skimmers and micrometer or even sub-micrometer nozzles. Such sources have been applied, for example, in the investigation of superfluidity and in neutral helium microscopy. However, up till now no source design allowing the precise positioning of the micro-skimmer relative to the nozzle has been available. This is an important issue because the relative position of skimmer and nozzle can influence the beam properties considerably. Here we present the design and implementation of a new molecular beam source, which allows an automatized, 50 nm precision positioning of the skimmer relative to the nozzle. The source is liquid nitrogen cooled and the temperature can be controlled between 110 K and 350 K with a temperature fluctuation of less than ±0.1 K over several hours. Beam intensity measurements using a 5 µm nozzle and a skimmer 5 µm in diameter are presented for stagnation pressures po in the range 3-180 bars. A 2D beam profile scan, using a 9.5 µm skimmer and a 5 µm nozzle is presented as a further documentation of the versatility of the new design and as an illustration of the influence of the relative skimmer-nozzle position on the beam properties.

Imaging with neutral atoms: a new matter-wave microscope.

Matter-wave microscopy can be dated back to 1932 when Max Knoll and Ernst Ruska published the first image obtained with a beam of focussed electrons. In this paper a new step in the development of matter-wave microscopy is presented. We have created an instrument where a focussed beam of neutral, ground-state atoms (helium) is used to image a sample. We present the first 2D images obtained using this new technique. The imaged sample is a free-standing hexagonal copper grating (with a period of about 36 microm and rod thickness of about 8 microm). The images were obtained in transmission mode by scanning the focussed beam, which had a minimum spot size of about 2.0 microm in diameter (full width at half maximum) across the sample. The smallest focus achieved was 1.9 +/- 0.1 microm. The resolution for this experiment was limited by the speed ratio of the atomic beam through the chromatic aberrations of the zone plate that was used to focus. Ultimately the theoretical resolution limit is set by the wavelength of the probing particle. In praxis, the resolution is limited by the source and the focussing optics.

Reduction of postoperative adhesions with an auto-crosslinked hyaluronan gel in gynaecological laparoscopic surgery: a blinded, controlled, randomized, multicentre study.

BACKGROUND: Following myomectomy, postoperative adhesions occur in many patients with adverse effects on fertility. This study investigated the applicability, safety and efficacy of an auto-crosslinked hyaluronan gel in preventing adhesion formation after laparoscopic myomectomy. METHODS: Fifty-two patients aged 22-42 years, undergoing surgery at four centres, were randomly allocated to receive either the gel or no adhesion prevention. The incidence and severity of postoperative adhesions were assessed laparoscopically after 12-14 weeks in a blinded, scored fashion. The primary efficacy variable was the presence/absence of postoperative adhesions at second-look. RESULTS: A nonsignificantly higher proportion of patients receiving the gel were free from adhesions (13 of 21; 62%) compared with control patients (9 of 22; 41%), with a statistically significant difference between the severity of uterine adhesions at baseline and at second-look (0.3 +/- 0.9 versus 0.8 +/- 1.0, P < 0.05). In subjects undergoing myomectomy without concomitant surgery, the proportion of adhesion-free patients was 8 of 12 (67%) and 4 of 11 (36%) (not significant) in the gel and control groups, respectively, with a significant difference in the mean severity scores (P < 0.05). In subjects without uterine adhesions before myomectomy, 12 of 18 (67%) and 8 of 20 (40%) patients in the gel and control groups, respectively were adhesion-free (not significant), with a significant difference in the severity of uterine adhesions (P = 0.05). CONCLUSIONS: Our results suggest that the auto-crosslinked hyaluronan gel may have a favourable safety profile and efficacious antiadhesive action following laparoscopic myomectomy.

Hyperthermal molecular beam deposition of highly ordered organic thin films.

We use a seeded supersonic molecular beam to control the kinetic energy of pentacene (C22H14) during deposition and growth on Ag(111). Highly ordered thin films are grown at low substrate temperatures (approximately 200 K) at kinetic energies of a few electron volts, as shown by low energy He diffraction and x-ray reflectivity spectra. In contrast, deposition of thermal molecules yields only amorphous films. Growth at room or higher temperature substrates yields films of poorer quality irrespective of the depositing beam energy. We find that after the first wetting layer is completed, a new ordered phase is formed, whose in-plane lattice spacings match one of the bulk crystal planes. The high quality of the films can be interpreted as the result of local annealing induced by the impact of the impinging high-energy molecules.

Pressure lavage under ultrasound guidance: a new approach for outpatient treatment of intrauterine adhesions.

OBJECTIVE: To present pressure lavage under ultrasound guidance (PLUG) as a new therapeutic procedure for selected cases of intrauterine adhesions (IUA). DESIGN: An open clinical investigation with no control group. SETTING: Teaching hospital. PATIENT(S): Seven consecutive patients referred to our department for secondary amenorrhea due to IUA. INTERVENTION(S): A newly developed technique based on sonohysterography was used to monitor the effects of intrauterine injections of saline solution on the continuous accumulation of saline in the uterine cavity for the mechanical disruption of IUA. MAIN OUTCOME MEASURE(S): Lysis of intrauterine adhesions, restoration of menses, and increased pregnancy rate in infertile patients. RESULT(S): Five patients with mild IUA obtained satisfactory lysis of adhesions by the use of the PLUG technique. A second-look hysteroscopy after 1 month showed that filmy adhesions persisted in two patients with moderate IUA. These adhesions were removed successfully during hysteroscopy. Restoration of menses was obtained and has continued in all patients. Two of the three infertile patients became pregnant. CONCLUSION(S): This technique is safe and ideal as an in-office procedure. PLUG allows complete lysis in mild IUA cases, and the need for therapeutic, and possibly follow-up hysteroscopy, can be avoided. In moderate IUA cases, the procedure may represent a useful initial step in reducing the need for operative hysteroscopy.

Dynamics of tearing modes during strong electron cyclotron heating on the FTU tokamak.

The localized electron cyclotron resonance heating power that can suppress sawteeth reconnection often drives m = 2 tearing modes in a tokamak operating at constant current. The dynamics of mode onset and coupled mode evolution is described in detail and compared with a nonlinear theoretical model that identifies the effects of mode coupling, finite inertia of the rotating islands, and wall braking.

Intraoperative ultrasound guidance for operative hysteroscopy. A prospective study.

OBJECTIVE: To evaluate the efficacy and safety of ultrasound (US) guidance as compared to laparoscopic monitoring during operative hysteroscopy. STUDY DESIGN: Prospective, open study including 81 patients undergoing operative hysteroscopy under US guidance for uterine septum and submucous myoma. Clinical and surgical outcomes were compared with those in an historical control group of 45 patients undergoing the same operation under laparoscopic guidance. RESULTS: US guidance proved satisfactory in all patients, and there were no complications due to insufficient visualization of the pelvic structures; in no case was conversion to laparoscopic guidance required. US scanning was most useful in determining the outer limit of the intramural component of submucous partial intramural myoma, allowing complete resection. During metroplasty, US guidance allowed extension of the resection beyond the normal limit conventionally defined by hysteroscopy; none required reintervention. By comparison, in the control group, a second attempt was required because the operation was insufficiently radical in four patients. CONCLUSION: US guidance was used successfully as the only visual aid for hysteroscopic surgery, comparing favorably with laparoscopy in terms of efficacy and safety.

Estroprogestin vs. gonadotrophin agonists plus estroprogestin in the treatment of endometriosis-related pelvic pain: a randomized trial. Gruppo Italiano per lo Studio dell'Endometriosi.

OBJECTIVE: This is a randomized clinical trial comparing estroprogestin (E/P) pill given for 12 months vs. gonadotrophin releasing hormone agonist (GNRHa) given for 4 months followed by E/P pill treatment for 8 months in the relief of endometriosis-related pelvic pain. METHODS: Eligible for the study were women with laparoscopically confirmed endometriosis and pelvic pain lasting 3-12 months after diagnosis. Eligible women were randomly assigned to treatment with E/P pill (gestroden 0.75 mg and ethynlestradiol 0.03 mg) for 12 months (47 patients) vs. tryptorelin 3.75 mg slow release every 28 days for 4 months followed by E/P pill for 8 months (55 patients). RESULTS: At baseline, dysmenorrhea was reported in 46 women allocated to E/P pill only (97.9%), and in all the 55 women allocated to GNRHa+E/P pill. The corresponding value at the 12 months follow-up visit was 14 subjects (35.9%) and 16 subjects (34.8%). The baseline median values of the multidimensional and analog scale were for dysmenorrhea 4 and 6 in the EP only and 3 and 6 in the GNRHa+E/P group. The corresponding value at the 12 months follow-up visit were 2 and 6 and 0 and 5. Non-menstrual pain was reported, respectively, at baseline and 12 month visit by 46 (97.9%) and 15 (38.5%) subjects in the E/P pill group and 49 (89.1%) and 17 (37.0%) of the GNRHa+E/P pill one. The baseline median values of the multidimensional and analog scale were for non-menstrual pain 3 and 5 in the E/P only and 2 and 6 in the GNRHa+E/P group. The corresponding values at the 12 month follow-up visit were 0 and 4 and 0 and 4. These differences between the two groups were not statistically significant. CONCLUSIONS: 1 year after randomization, the two treatment schedules show similar relief of pelvic pain in women with endometriosis.

True incidence of vaginal vault prolapse. Thirteen years of experience.

OBJECTIVE: To assess the true incidence of vaginal vault prolapse after hysterectomy. STUDY DESIGN: The records of 2,670 patients who had undergone hysterectomy between 1983 and 1987 were reviewed. From this population, 448 patients were selected for follow-up study. The mean follow-up phase was 11 years (range, 9-13). Patients were divided into two groups according to the presence or the absence of genital prolapse at hysterectomy. Pelvic examination was performed in order to identify the presence of vault prolapse. Pelvic support was assessed using Baden and Walker's "halfway description." RESULTS: Five of the 2,670 patients who had undergone hysterectomy at our institution returned on their own initiative for surgical correction of vault prolapse. Using the modalities in the literature, the incidence of vault prolapse was 0.4%. Instead, on pelvic examination, the incidence of vault prolapse was 4.4% (20 patients in a group of 448). Fourteen of the 20 with vault prolapse had previously undergone vaginal hysterectomy for genital prolapse: six had had abdominal hysterectomy for benign disease, excluding genital prolapse. Therefore, the incidence of vaginal vault prolapse was 11.6% (14/120 patients) when hysterectomy had been performed for genital prolapse and 1.8% (6/328) when hysterectomy had been performed for other benign diseases. In the latter group (328 patients), all the cases of vault prolapse developed after abdominal hysterectomy: the incidence was 2% (6/308 patients); no case (0/20 patients) of vault prolapse developed after vaginal hysterectomy that had been performed on patients without genital prolapse. The primary risk factor for vaginal vault prolapse in this study, was obesity. Obese subjects were significantly more susceptible to developing the condition when compared to nonobese (P < .001). CONCLUSION: Our data show that there is a low incidence of vaginal vault prolapse when hysterectomy is performed in the absence of defects in pelvic support. A comparison of our method and those described in the literature to determine the incidence of vaginal vault prolapse showed that this event is often underevaluated if long-term follow-up after hysterectomy is not carried out.

Acute abdomen following dermoid cyst rupture during transvaginal ultrasonographically guided retrieval of oocytes.

We report a case of acute abdomen due to puncture of a dermoid cyst during oocyte aspiration, which required laparotomy. A woman who had undergone an in-vitro fertilization and embryo transfer required hospitalization due to onset of an acute abdomen. An ultrasonographic scan showed a pelvic mass with the features of dermoid cyst. The patient required diagnostic laparotomy which confirmed the presence of a ruptured dermoid cyst with subsequent peritonitis.