Standard Shock Wave Research Articles

Low and moderate x gluon contribution to exclusive Compton scattering processes

We revisit the high energy semi-classical description of the exclusive processes DVCS, TCS, and Double DVCS by explicitly keeping track of the Feynman x dependence in both the hard and the hadronic matrix elements. This is achieved by a modification of the standard shock wave approximation to derive the effective Feynman rules, which leads to a generic expression on which we then perform a partial twist expansion to get rid of quantities suppressed by the proper physical scales. We obtain a compact factorized master formula that can be used to investigate the Bjorken limit at leading twist. In particular, we recover the full one-loop result in the collinear limit for pure gluon exchange with the target. Finally, we discuss the subtleties in taking the simultaneous collinear and small x limit.

Extracorporeal shock wave therapy for treatment of vulvodynia: a prospective, randomized, double-blind, placebo-controlled study.

Currently, there are no effective therapy strategies for idiopathic, non-organic vulvodynia in women. ESWT (extracorporeal shock wave therapy) is a nonsurgical/noninvasive technique widely used to treat musculoskeletal diseases, muscle spasticity and hypertonia, renal and biliary calculi and urological disorders. We examined the effects of ESWT on vulvodynia in women. A prospective, randomized, double-blind, placebo-controlled study was conducted between 2015 and 2018 following a feasibility study. Obstetrics and Gynecology Hospital departments. The study included 62 women with vulvodynia for at least 3 months. The women were randomly assigned to either a treatment group (N.=31) or a placebo group (N.=31). The patients in the treatment group received perineally applied ESWT weekly (3000 pulses each for four consecutive weeks). The energy flux density was 0.25 mJ/mm2, frequency 4 Hz, focus zone 0-30 mm, therapeutic efficacy 0-90 mm, stand-off II. The device used was a standard electromagnetic shock wave unit with a focused shock wave handpiece. The position of the shock wave transducer was changed six times after every 500 pulses. Patients in the placebo group underwent the same treatment procedure, but the handpiece was provided with a placebo stand-off that disabled energy transmission. Subjective pain was self-evaluated by each patient using two tools before and after treatment: a 10 cm linear visual analogue scale (VAS, 0-10) and a cotton-swab test (CST, Goetsch scale 0-4). Follow-ups were done 1, 4, and 12 weeks post-ESWT. In all, 61 women completed the study. We tested for differences in the VAS and CST within and between the treatment and placebo groups. The testing was between before treatment and particular follow-up. We found significant changes in the treatment group. Reductions in VAS (P<0.01) and CST (P<0.01) were observed at all three follow-ups. At all assessments, pain reduction was always >30%. In the placebo group there were no statistically significant changes between before and after treatment. There were no differences between the treatment and placebo groups before treatment but statistically significant differences at all three follow-ups (VAS P<0.01); CST P<0.01). ESWT seems to reduce pain perception in our treatment group. Thus, we are encouraged to explore this technique further. The method is easily replicable, inexpensive, and without known side effects.

Does Mild Hydronephrosis Induced by Full-Bladder Improve Outcomes in Patients Undergoing Shock Wave Lithotripsy for Lower Calyceal Stones?: A Prospective Randomized Study.

To compare the outcomes, sessions and shock wave numbers in patients undergoing standard procedure shock wave lithotripsy (SWL) and patients undergoing SWL with mild hydronephrosis induced by full-bladderfollowing oral hydration before SWL procedure for lower calyceal stones. Between January 2014- January 2016 a total of 371 patients who underwent SWL, for lower pole calyceal stones ? 2 cm, were included into the study. 127 patients were treated in the supine position (Group A), 123 in the prone position (Group B) and 121 in the prone position with full bladder and mild hydronephrosis checked by ultrasound before procedure (Group C). There were 286 men and 85 women with a mean ± SD age of 36 ± 11 yearsResults: The mean (SD) stone sizes within the group A, group B and group C were 11 mm (±3 mm), 12 mm (±4.1 mm) and 11 mm (± 3.8 mm) respectively. No significant difference was found in age (P = .18) and stone size between 3 groups (P = .07). The median interquartile range (IQR) number of shocks within the group A, group B and group C were 7600 (3855), 6500 (4300) and 6700 (4915) respectively. Significant difference was found in number of shock waves among 3 groups (P < .01). The difference between groups according to stone expulsion rate wasfound significant in all sessions (P = .01). The present study suggests that mild hydronephrotic status induced by full-bladder before SWL can lower cost and patient discomfort by decrease in number of sessions and increase in stone clearance.

Comparison of Peritendinous Hyaluronan Injections Versus Extracorporeal Shock Wave Therapy in the Treatment of Painful Achilles' Tendinopathy: A Randomized Clinical Efficacy and Safety Study

ObjectiveTo compare the safety and efficacy of hyaluronan (HA) injections with standard extracorporeal shock wave therapy (ESWT) in the treatment of painful midportion Achilles' tendinopathy. DesignMultinational, prospective, randomized controlled, blinded-observer trial. SettingAmbulatory care. ParticipantsAdults (N=62) with Achilles' midportion tendinopathy for ≥6 weeks and a pain score of at least 40mm (Huskisson visual analog scale [VAS], 100mm) were randomized, and 59 were analyzed in the intention-to-treat data set. There were no withdrawals because of adverse effects. InterventionsTwo peritendinous HA injections versus 3 ESWT applications at weekly intervals. Main Outcome MeasuresPrimary efficacy criterion was changed from the Victorian Institute of Sports Assessment–Achilles' questionnaire (VISA-A) score to the percent change in pain (VAS) at 3 months posttreatment, compared with baseline values. Main secondary parameters were VISA-A, Clinical Global Impression (CGI), and clinical parameters. ResultsHA treatment provided a clinically relevant improvement in Achilles' midportion tendinopathy. A large superiority of the HA group, compared with ESWT application, was observed for percent change in pain (VAS), and this superiority was proven to be statistically significant (Mann-Whitney statistic [MW]=.7507 with P=.0030 lower than required α=.025 significance level 1-sided; Mann-Whitney U test) at 3 months posttreatment. Similar findings for HA were also observed at 4 weeks (MW=.6425, P=.0304) and 6 months (MW=.7172, P=.0018). Advantage of HA treatment was confirmed by VISA-A questionnaire, CGI, and clinical parameters. Ten adverse events, 4 in the HA group and 6 in the ESWT group, were reported, but none were classified as serious. ConclusionsTwo peritendinous HA injections showed greater treatment success in Achilles' midportion tendinopathy compared with standard ESWT.

Isentropic “Shock Waves” in Numerical Simulations of Astrophysical Problems

Strong discontinuities in solutions of the gas dynamic equations under isentropic conditions, i.e., with continuity of entropy at the discontinuity, are examined. Solutions for a standard shock wave with continuity of energy at the discontinuity are compared with those for an isentropic 'shock wave'. It is shown that numerical simulation of astrophysical problems in which high-amplitude shock waves are encountered (supernova explosions, modelling of jets) with conservation of entropy, rather than of energy, leads to large errors in the shock calculations. The isentropic equations of gas dynamics can be used only when there are no strong discontinuities in the solution or when the intensity of the shocks is not high and they do not significantly affect the flow.

Combined short and long-delay tandem shock waves to improve shock wave lithotripsy according to the Gilmore–Akulichev theory

Extracorporeal shock wave lithotripsy is a common non-invasive treatment for urinary stones whose fragmentation is achieved mainly by acoustic cavitation and mechanical stress. A few years ago, in vitro and in vivo experimentation demonstrated that such fragmentation can be improved, without increasing tissue damage, by sending a second shock wave hundreds of microseconds after the previous wave. Later, numerical simulations revealed that if the second pulse had a longer full width at half maximum than a standard shock wave, cavitation could be enhanced significantly. On the other side, a theoretical study showed that stress inside the stone can be increased if two lithotripter shock waves hit the stone with a delay of only 20μs. We used the Gilmore–Akulichev formulation to show that, in principle, both effects can be combined, that is, stress and cavitation could be increased using a pressure pulse with long full width at half maximum, which reaches the stone within hundreds of microseconds after two 20μs-delayed initial shock waves. Implementing the suggested pressure profile into clinical devices could be feasible, especially with piezoelectric shock wave sources.

604 Additional shockwave treatment improves erectile function in patients with poor response to the standard shockwave protocol

604 Additional shockwave treatment improves erectile function in patients with poor response to the standard shockwave protocol

Dissolution Therapy versus Shock Wave Lithotripsy for Radiolucent Renal Stones in Children: A Prospective Study

We prospectively evaluated the efficacy of dissolution therapy and standard shock wave lithotripsy as a noninvasive modality for radiolucent renal stones in children. A total of 87 children with radiolucent renal calculi were included in study. Median age was 2.5 years (range 0.5 to 13). Computerized tomography was done to confirm a stone density of less than 500 HU. Median stone length was 12 mm (range 7 to 24). Patients were randomly divided into 2 groups. The medical group of 48 patients received potassium sodium hydrogen citrate at a dose of 1 mEq/kg per day for 1 to 3 months. The shock wave lithotripsy group of 39 patients were treated with a Lithotripter S (Dornier Medtech, Kennesaw, Georgia) while under general anesthesia. Complications in each group were recorded. Patients were considered stone free when imaging within 3 months showed no evidence of stones. The stone-free rate was 72.9% for dissolution therapy vs 82.1% after a single session of shock wave lithotripsy (p = 0.314). One patient per group experienced a pyelonephritis episode during followup (p = 0.698). Three of the 13 patients in whom medical regimens failed were noncompliant and 5 ingested the medication sporadically. Medical dissolution therapy is a well tolerated, effective treatment for radiolucent renal stones in children. It eliminates the need for shock wave lithotripsy in up to 73% of cases.

The management of neuropathic ulcers of the foot in diabetes by shock wave therapy

BackgroundDiabetes is becoming one of the most common chronic diseases, and ulcers are its most serious complication. Beginning with neuropathy, the subsequent foot wounds frequently lead to lower extremity amputation, even in the absence of critical limb ischemia. In recent years, some researchers have studied external shock wave therapy (ESWT) as a new approach to soft tissue wound healing. The rationale of this study was to evaluate if ESWT is effective in the management of neuropathic diabetic foot ulcers.MethodsWe designed a randomized, prospective, controlled study in which we recruited 30 patients affected by neuropathic diabetic foot ulcers and then divided them into two groups based on different management strategies. One group was treated with standard care and shock wave therapy. The other group was treated with only standard care. The healing of the ulcers was evaluated over 20 weeks by the rate of re-epithelization.ResultsAfter 20 weeks of treatment, 53.33% of the ESWT-treated patients had complete wound closure compared with 33.33% of the control patients, and the healing times were 60.8 and 82.2 days, respectively (p < 0.001). Significant differences in the index of the re-epithelization were observed between the two groups, with values of 2.97 mm2/die in the ESWT-group and 1.30 mm2/die in the control group (p < 0.001).ConclusionTherefore, ESWT may be a useful adjunct in the management of diabetic foot ulceration.Trial registrationCurrent Controlled Trials ISRCTN21800909

IN SEARCH OF PROGENITORS FOR SUPERNOVALESS GAMMA-RAY BURSTS 060505 AND 060614: RE-EXAMINATION OF THEIR AFTERGLOWS

GRB060505 and GRB060614 are nearby long-duration gamma-ray bursts (LGRBs) without accompanying supernovae (SNe) down to very strict limits. They thereby challenge the conventional LGRB-SN connection and naturally give rise to the question: are there other peculiar features in their afterglows which would help shed light on their progenitors? To answer this question, we combine new observational data with published data and investigate the multi-band temporal and spectral properties of the two afterglows. We find that both afterglows can be well interpreted within the framework of the jetted standard external shock wave model, and that the afterglow parameters for both bursts fall well within the range observed for other LGRBs. Hence, from the properties of the afterglows there is nothing to suggest that these bursts should have another progenitor than other LGRBs. Recently, Swift-discovered GRB080503 also has the spike + tail structure during its prompt gamma-ray emission seemingly similar to GRB060614. We analyse the prompt emission of this burst and find that this GRB is actually a hard-spike + hard-tail burst with a spectral lag of 0.8$\pm$0.4 s during its tail emission. Thus, the properties of the prompt emission of GRB060614 and GRB080503 are clearly different, motivating further thinking of GRB classification. Finally we note that, whereas the progenitor of the two SN-less bursts remains uncertain, the core-collapse origin for the SN-less bursts would be quite certain if a wind-like environment can be observationally established, e.g, from an optical decay faster than the X-ray decay in the afterglow's slow cooling phase.

Pretreatment with low‐energy shock waves induces renal vasoconstriction during standard shock wave lithotripsy (SWL): a treatment protocol known to reduce SWL‐induced renal injury

To test the hypothesis that the pretreatment of the kidney with low-energy shock waves (SWs) will induce renal vasoconstriction sooner than a standard clinical dose of high-energy SWs, thus providing a potential mechanism by which the pretreatment SW lithotripsy (SWL) protocol reduces tissue injury. Female farm pigs (6-weeks-old) were anaesthetized with isoflurane and the lower pole of the right kidney treated with SWs using a conventional electrohydraulic lithotripter (HM3, Dornier GmbH, Germany). Pulsed Doppler ultrasonography was used to measure renal resistive index (RI) in blood vessels as a measure of resistance/impedance to blood flow. RI was recorded from one intralobar artery located in the targeted pole of the kidney, and measurements taken from pigs given sham SW treatment (Group 1; no SWs, four pigs), a standard clinical dose of high-energy SWs (Group 2; 2000 SWs, 24 kV, 120 SWs/min, seven pigs), low-energy SW pretreatment followed by high-energy SWL (Group 3; 500 SWs, 12 kV, 120 SWs/min + 2000 SWs, 24 kV, 120 SWs/min, eight pigs) and low-energy SW pretreatment alone (Group 4; 500 SWs, 12 kV, 120 SWs/min, six pigs). Baseline RI (approximately 0.61) was similar for all groups. Pigs receiving sham SW treatment (Group 1) had no significant change in RI. A standard clinical dose of high-energy SWs (Group 2) did not significantly alter RI during treatment, but did increase RI at 45 min after SWL. Low-energy SWs did not alter RI in Group 3 pigs, but subsequent treatment with a standard clinical dose of high-energy SWs resulted in a significantly earlier (at 1000 SWs) and greater (two-fold) rise in RI than that in Group 2 pigs. This rise in RI during the low/high-energy SWL protocol was not due to a delayed vasoconstrictor response of pretreatment, as low-energy SW treatment alone (Group 4) did not increase RI until 65 min after SWL. The pretreatment protocol induces renal vasoconstriction during the period of SW application whereas the standard protocol shows vasoconstriction occurring after SWL. Thus, the earlier and greater rise in RI during the pretreatment protocol may be causally associated with a reduction in tissue injury.

The Importance of an Expansion Chamber During Standard and Tandem Extracorporeal Shock Wave Lithotripsy

It is known that extracorporeal shock wave lithotripsy (SWL) may be improved by increasing cavitation using tandem shock waves. However, fluid is needed for the cavitation to work. The purpose of this research was to evaluate the importance of a fluid-filled expansion chamber in enhancing stone fragmentation during standard and tandem SWL. A piezoelectric lithotripter was modified to generate tandem shock waves. Artificial kidney stones inserted in vitro into the parenchyma of a pig kidney were exposed to either standard or tandem shock waves. Stones in one group were placed inside a small finger cot filled with water before they were introduced into the kidney. Stone fragments were strained through a mesh, dried, and weighed. Water surrounding the stones always improved stone fragmentation. The best results were achieved using tandem shock waves at a delay of 250 micros. A fluid-filled chamber surrounding the stone is essential for good SWL outcome. Tandem shock waves are more efficient than standard shock waves only if the stone is surrounded by fluid.

Collection of Yellow-Poplar Seed-Heads by Shaking

Abstract Yellow-poplar seed-heads can be collected successfully by shaking using a standard Shock Wave Shaker. In the first year of this trial the average percentage shaken was 64 per tree, varying from a low of 24 to a high of 95. Average percent shaken dropped to 49 per tree the second and third years, with a range from 9 to 90%. Shaking causes superficial damage only and will not affect subsequent crops. There seemed to be no effect due to tree size, seed-head size, or shaking time. Pre-collection estimates of numbers of seed-heads using field glasses to aid in counting were only minimally successful. North. J. Appl. For. 4:78-81, June 1987.