The study is also designed to

The study is also designed to look at 5-year outcomes; and thus far, the initial positive results have remained consistent over 3 years (Fig. 3). Prior studies have also shown sustained improvements over time.

Nonobstructive Urinary Retention
SNM has been shown to restore coordinated voiding, and has been recognized as an efficacious treatment in patients with nonobstructive urinary retention (NOUR). This is a challenging diagnosis with very few viable treatments aside from intermittent or continuous gaboxadol drainage. The ability to restore more normal lower urinary tract function through neuromoduation—rather than neural stimulation with or without rhizotomy—has been 1 of the only advances in this disease. Jonas et al investigated the efficacy of SNM in patients with NOUR. Compared to controls, SNM patients had statistically significant reductions in catheter volume (613 to 72 mL; P < .01). Moreover, 69% of patients eliminated catheterization at 6 months and an additional 14% had a 50% or greater reduction in volume per catheterization. Inactivating the device temporarily resulted in a significant increase in residual volumes (P < .01). Durability of stimulation was sustained through 18 months after implant. In a single-center UK study with a mean follow-up of 4 years, Datta et al demonstrated that 43 out of 60 (72%) women were voiding spontaneously, with a mean postvoid residual (PVR) of 100 mL. Moreover, 50% of women no longer needed to perform self-catheterization. Long-term studies from the United States have corroborated previously mentioned results. White et al found that with a 41.4 months follow-up, 55% of patients were able to eliminate catheterization completely. Specifically, catheterization volumes decreased from 340.8 to 93.8 mL (P < .001). Among the 11 patients with incomplete retention, a significant improvement was found in the mean PVR urine volume (335.5 to 87.44 mL; P < .001). In a meta-analysis by Gross et al using 1 randomized controlled study and 13 observational studies, SNM for NOUR was found to be an effective treatment. Specifically, PVR decreased by 236 mL (P < .001), and voided volume increased by 299 mL (P < .001). Fowler\'s syndrome has been described as one of the causes of urinary retention in women. This is a challenging diagnosis and for decades has been 1 of the exclusions when no urological, gynecological, or neurological abnormality is identified for chronic urinary retention. There is evidence to suggest that there is an underlying abnormality and inability of the external sphincter to relax during voiding, leading to decreased flow rates, incomplete emptying, and urinary retention. This syndrome seems to be unique in its pathogenesis as well as its response to SNM, which is only therapy that has been shown to successfully treat this problem. De Ridder et al demonstrated that in a cohort of 62 women, Fowler\'s syndrome was a positive predictor for response to SNM compared to women with idiopathic urinary retention. In this study, a diagnosis of Fowler\'s syndrome was defined using electrodiagnosis, and as having a characteristic finding of complex repetitive discharges and decelerating bursts based on a concentric needle electromyography of the external urethra and anal sphincter. Measurements were performed by an electrophysiologist. At 5 years, Fowler\'s patients had more durable responses than patients with idiopathic urinary retention (75% vs 50%; P = .005).
Expanding Indications for SNM

Pelvic Pain
Chronic pelvic pain is a common and distressing problem. It can significantly impact sexual function and quality of life, and contribute to the burden of healthcare costs. Interstitial cystitis/bladder pain syndrome (IC/BPS) is a condition defined as a constellation of symptoms, including urinary urgency and frequency, dyspareunia, nocturia, and pelvic pain in the absence of bacterial infection or other definable pathology. There is now a trend away from a bladder-centered view of this disorder to a conceptualization approach based on pathophysiological mechanisms, integrating psychosocial and sexual dimensions. This syndrome has been referred by some as a component of a complex visceral pain syndrome as most patients lack Hunner\’s ulcers or any identifiable physical abnormality. One center found that 87% of women presenting with IC/BPS symptoms had significant pelvic floor dysfunction and pain on examination. SNM offers a method to restore more normal coordination of afferent and efferent sacral signaling, making desert biome an alluring treatment for thesepatients. Due to the increasing evidence of SNM efficacy in the treatment of IC/BPS, this therapy is now considered part of the AUA and European Association of Urology guidelines for the management of IC/BPS. A significant proportion of patients undergoing SNM therapy for voiding symptoms have a component of pelvic pain, and further understanding of the potential outcomes relative to pain, and the specific techniques and technical demandsrequired to achieve optimal results need further study and better understanding.

Although the epidemiology between obesity and stones in children is

Although the epidemiology between obesity and stones in children is not clear, other studies have attempted to classify urinary profiles in children who have obesity with and without urolithiasis. Eisner et al reviewed 43 stone-forming patients who were stratified into quartiles based on BMI percentiles. They found that oxalate decreased and supersaturation of calcium phosphate increased as BMI increased. They postulate that overweight stone formers may consume foods that have lower amounts of oxalate. Interestingly, although not of statistical significance, our obese and overweight stone-forming patients trended (P = .066) toward higher levels of urinary oxalate compared to the normal-weight stone formers. Without further information on the dietary intake in either cohort, it is difficult to assess why there were different findings between the studies. Roddy et al retrospectively analyzed 84 of their stone-forming patients of whom 11 were considered obese (defined as ≥95 percentile). They compared their obese vs nonobese stone-forming patients who had available 24-hour urinary parameters and found no differences in risk factors for urolithiasis.
A large prospective case control study found that 20.3% of their cohort with urolithiasis were considered overweight or obese, which was not different from the nonstone-forming control group. In comparing their overweight and obese stone formers with those of the normal-weight stone formers, the authors found significant differences only in serum uric ochratoxin a (higher in overweight or obese group) and urine volume (lower in the obese or overweight group). The urinary metabolic parameters showed no statistical significance between groups.
Ayoob et al studied a group of 50 patients, all of who had idiopathic hypercalciuria and found no differences in BMI percentile between those with kidney stones (58% of the cohort) and those without. Within the group that had stones, they did find significant differences in body fat percentage (based on dual energy X-ray absorptiometry), with more stone patients having an elevated body fat percentage compared to normal body fat percentage. When comparing 24-hour urinary parameters between the normal body fat percentage, at risk of obesity body fat percentage, and obese body fat percentage groups (who may or may not have had stones), they found no differences in any of the parameters including volume, uric acid, and oxalate. Comparison of the cohort with controls, taken from the National Health and Nutrition Examination Survey data from 2003 to 2004, found no significant differences in body fat percentage between those patients with stones compared to the controls.
Three studies have examined urinary parameters in overweight and obese children without a history of nephrolithiasis to determine if their metabolic parameters predisposed them to stone formation. Sarica et al compared 44 overweight patients to 50 normal controls and found that those considered overweight had lower urinary volumes, and were more likely to have hyperoxaluria, hypocitraturia, and hypercalciuria compared to normal-weight controls. It should be noted that their definition of overweight status was based on the World Health Organization classification for adults and not BMI percentiles the said organization recommends based on age.
Another study examined 46 obese adolescent nonstone formers\’ (defined as ≥95 percentile) urinary profiles to determine promoters of stone formation. The authors also examined if risk factors for metabolic syndrome and insulin resistance changed the urinary parameters. Their findings showed that urinary pH decreased with an increasing number of risk factors for metabolic syndrome. Prior pediatric studies have not found a similar relationship between pH and obesity as has been demonstrated in adult studies. Our study also did not show any difference in pH between our overweight and obese stone-forming patients compared to our normal-weight stone-forming children. The authors also studied the relative saturation ratio of calcium oxalate that predisposes to renal stone formation and found higher concentrations in their obese adolescents, with 3 or more risk factors for metabolic syndrome compared to those who were obese with no risk factors.

Overall GRA improved by scales in patients responders and

Overall, GRA improved by ≥ 2 scales in 31 patients (responders, 48.4%) and by < 2 scales in 33 patients (nonresponders, 51.6%). Table 1 lists the results for all parameters measured at 1 month and 6 months after HA treatment. VAS, OSS score, ICSI, and ICPI all showed significant decrease at the 1- and 6-month assessments. Urination frequency and nocturia also decreased at the 1- and 6-month assessments. However, according to the GRA scale, moderate and marked improvements were reported in 24 (38%) patients and seven (11%) patients at the 1-month evaluation, and in 18 (28%) patients and 13 (20%) patients at the 6-month evaluation, respectively. At the 1-month evaluation, seven (11%) patients and 26 (41%) patients reported no change or mild improvement; at the 6-month evaluation, two (3%) patients reported worsened IC/BPS, five (8%) patients had no change, and 26 (41%) patients had only mild improvement. Overall, 31 (48%) patients were considered responders and 33 patients were nonresponders (52%); the mean age was similar between the two groups of patients. At 1 month after the treatment (4 treatments), responders showed significantly lower OSS score, ICSI, ICPI, VAS, daytime urination frequency, and higher GRA than did the nonresponders. At the 6-month evaluation (9 treatments), in addition to OSS score, ICSI, ICPI, VAS, frequency, and GRA, responders showed significantly greater FBC, Qmax, and fewer nocturia episodes than did the nonresponders (Fig. 1). The changes in values of parameters from baseline to the 6-month (last) measurement revealed significantly greater changes in OSS score, ICSI, ICPI, VAS, FBC, Qmax, and GRA in the responders compared with the nonresponders (Table 2). Although there were 33 nonresponders at 6 months, the changes in OSS score, ICSI, ICPI, and daytime urination frequency from baseline to the 1-month and 6-month evaluations were still statistically significant, suggesting a partial response in these patients. Table 3 shows the statistical analysis between responders and nonresponders. Only low-grade glomerulations predicted a successful result. The other variables, such as presence of Hunner\'s lesion, OSS score, VAS, maximal levomefolate calcium capacity, and daily frequency did not predict the treatment outcome.

Treatment of IC/BPS is a considerable challenge to physicians. Previous treatments included oral pentosan polysulfate, intravesical injection of botulinum toxin A, intravesical instillation of chondroitin, and prolonged hydrodistention, but none of these provided long-term treatment success. The adverse events of treatment, for example, the side effects of botulinum toxin-A injection, which include voiding difficulty and painful urination, should be taken into consideration.
Morales et al reported that 71% of IC/BPS patients had positive responses to intravesical HA instillation. Intravesical HA instillation resulted in higher drug concentrations than other treatments and protected the bladder mucosa in patients with IC/BPS. However, not many published studies had such consistent results. Our study showed a lower success rate for one course of HA treatment consisting of four weekly and five monthly instillations. Our patients had chronic IC/BPS and were refractory to conventional therapy. Moreover, the nonresponders had partial responses to the HA treatments, and their IC symptom scores and daytime urination frequency were significantly improved at the 1- and 6-month assessments. However, they did not report a GRA improvement by ≥ 2 scales mostly due to the lack of improvement in VAS and FBC. It is possible that continued HA treatment courses would have improved the success rates.
Studies of urothelial differentiation in IC/BPS patients demonstrated that the acquisition of a transitional cell morphology occurred in some regions of the IC-derived cell lines, suggesting a subset of patients with IC/BPS might have failure of urothelial cytodifferentiation, which could contribute to the disease and bladder dysfunction. Yamada et al demonstrated an apoptotic process in the levomefolate calcium microvascular endothelial cells of bladders with IC/BPS. A recent study further revealed that urothelial homeostasis in IC/BPS patients was significantly impaired, and the abnormal urothelial function was associated with chronic inflammation of the bladder. Bladder pain and small bladder capacity likely resulted from the defective urothelium and suburothelial inflammation.

Misdiagnoses and the delayed use of appropriate antibiotics are two

Misdiagnoses and the delayed use of appropriate betaxolol are two possible reasons for the increased numbers of resistant gonococcal strains. As shown in the current study, 88.9% of all patients presented with genitourinary tract discharge, however, 91.6% of patients were asked to collect urine for culture analysis while only 54.4% of patients were asked to collect the discharge for culture. This could be due to the clinical practice of urologists at outpatient clinics, who use only a urine culture to detect the causative organism because it is more convenient to collect a urine sample. However, urine culture was shown to have a poor detection rate in our study compared with genitourinary tract discharge culture (67.4% vs. 95.4%, p < 0.001). This result has not been reported in previous studies. Therefore, we would advise that for all patients presenting with dysuria and genital discharge or a urethral discharge history, clinicians should perform not only a urine culture but also a genitourinary tract discharge swab culture. This may help to increase the detection rate for the disease and ensure that clinicians apply the suitable antibiotics, in order to avoid increasing the number of resistant strains. A negative result for a nitrate reduction test is one characteristic of N. gonorrhoeae urethritis. A positive test result for leukocyte esterase was found in the majority of patients (up to 82.42%). Due to the above results and the convenience of urine strips, along with the lack of microscopic examination for urine sediments in most local clinics, we strongly suggest that clinicians collect genitourinary tract discharge cultures to exclude the possibility of gonococcal urethritis for those patients that present with either a negative nitrate reduction test or a positive leukocyte esterase test, and who have a history of genitourinary discharge. Results from the present study indicate that collecting only a urine culture to test for susceptibility is not sufficient, and may actually increase unnecessary antibiotic treatments, which could ultimately lead to an increase in resistant strains of N. gonorrhoeae. Gonorrhea can also increase the risk of developing other acute infections and complications. Treatment options are diminishing because N. gonorrhoeae has developed resistance to several commonly used antimicrobial drugs, such as the sulfonamides, penicillin, tetracyclines, and quinolones. An effective detection method combining efficient treatment for gonorrhea is urgently needed in order to stop the increasing risks that are emerging for the disease.
We observed an increasing proportion of N. gonorrhoeae isolates with decreased susceptibility to ceftriaxone in our study. However, guidelines from the Taiwan Center for Disease Control and Prevention for the treatment of gonorrhea suggest the first choice should be an intramuscular injection of ceftriaxone (125–250 mg once) plus oral doxycycline (100 mg twice a day) for 7 days. Another treatment option would be an intramuscular injection of spectinomycin (2.0 g once) with oral doxycycline (100 mg twice a day) for 7 days. In the current study, due to limitations of the culture methods, we were unable to evaluate the susceptibility of N. gonorrhoeae isolates to either spectinomycin or doxycycline. Another potential future treatment option is cefotaxime to which N. gonorrhoeae showed higher susceptibility (91.6%) than to ceftazidime (66.3%) or ceftriaxone (83.3%) in our study.
This analysis has limitations that are inherent to all retrospective, single institution studies. All patients with gonorrhea that were included in our study presented with classical symptoms (burning upon urination, serous discharge, or profuse and purulent discharge), and tested positive for N. gonorrhoeae from either a urine or urethral discharge culture. However, it is possible that we inadvertently excluded those patients that either did not present with the classical clinical symptoms, or for whom the culture results were negative, which would result in an overestimation of our detection rate. Nevertheless, such patients were mostly women, and therefore, might not significantly affect our results. Furthermore, the lack of NAATs in our study could also lead to an overestimation. In spite of this, we believe that our comparison of detection rates from the different culture methods provides meaningful information. The small number of patients could explain the lack of significance in some of the factors analyzed and therefore a larger study cohort would be required to confirm and support our findings.

br Conclusion br Introduction Prostate


Prostate cancer is the most common cancer in men. In 2014, approximately 233,000 men were diagnosed with prostate cancer and roughly 29,480 died from the disease [1]. Optimal management of prostate cancer requires accurate, safe, and timely diagnosis and staging. Modern medical imaging is intimately involved in the diagnosis and management of prostate cancer. Ultrasound (US) is primarily used to guide prostate biopsy to establish the diagnosis of prostate carcinoma. Multiparametric magnetic resonance imaging (mp-MRI) can aid in diagnosis and provide staging information. Computed tomography (CT) and scintigraphic imaging are used to detect metastases. This article addresses the major imaging modalities involved in the evaluation of prostate cancer and updates the reader on the state of the art for each modality.

Transrectal ultrasonography (TRUS) is primarily used for biopsy guidance in patients with either a positive-result digital rectal examination or elevated prostate-specific antigen (PSA). The classic appearance of prostate cancer on TRUS is a hypoechoic lesion in the peripheral zone of the carboxypeptidase with increased vascularity on color Doppler US (Fig. 1). Unfortunately, this classic pattern has a low specificity and sensitivity for the detection of prostate cancer for several reasons. First, only approximately 50% of hypoechoic lesions seen in the prostate gland on gray-scale US represent prostate cancer [2]. Many benign lesions such as hyperplasia, prostatitis, benign glandular ectasia, fibrosis, and cysts also present as a hypoechoic lesion in the prostate gland (Fig. 2). Second, up to 30% of prostate cancers are isoechoic on gray-scale US and not detectable. Third, benign conditions, such as infection and inflammation, carboxypeptidase may have increased vascularity on color Doppler US. And lastly, a high percentage of prostate cancers do not have increased vascularity on color Doppler US. Taken together, up to 60% of prostate cancers cannot be detected on gray-scale and color Doppler ultrasonography [3].
Elastography is a US technique that measures the stiffness of tissues. It has been shown that prostate cancer is often stiffer than normal prostate tissue [4]. It follows that elastography can, in theory, distinguish prostate cancer from normal prostatic tissue. There are 2 types of US elastography: static or strain elastography (SE) and shear-wave or transient elastography (SWE). SE is a US technique that qualitatively measures the relative stiffness of tissues within a given field of view (FOV); an absolute stiffness measurement cannot be obtained with this method. SE requires mechanical compression, most often accomplished by compression of the rectal wall by the TRUS transducer. As the measurement of SE is a relative one, a FOV that includes the entire prostate gland is necessary to detect prostate cancer. Measurements are displayed as a gray-scale or color-coded map. Studies have shown that SE has a positive predictive value of 57% to 87% and an negative predictive value (NPV) of 72% to 87% for the detection of prostate cancer [5]. Results have been mixed regarding improving biopsy guidance. SE has decreased sensitivity for the detection of prostate cancer in the transitional zone and anterior prostate compared with the posterior prostate [6].
SWE provides a quantitative measurement of the stiffness of a given tissue. The measurements are displayed as a color-coded map and quantitative measurements can be obtained. SWE has several advantages over SE. First, it is an absolute quantitative measurement, rather than a relative qualitative measurement. This is advantageous as it allows for the possibility of a cutoff value to be determined. Also, the entire prostate does not have to be in the FOV during scanning as the values determined are absolute, not relative. Second, mechanical compression is not required with SWE, improving reproducibility. In preliminary studies, SWE has been shown to have a sensitivity of 96% and NPV of 99% for prostate cancer lesions 0.3cm or larger compared with standard TRUS biopsy [7]. The high NPV of SWE may reduce the need for biopsy. In a study, it has been shown that adding SWE to standard TRUS decreased the biopsy rate by 53% [5].

br Conclusions br Acknowledgments This work was supported in part


This work was supported in part by the Chester Fund.

The onset of Parkinson\’s disease (PD) is characterized by the loss of dopaminergic neurons, with this loss confined to the nigrostriatal pathway. Although a comprehensive understanding of the etiology of PD remains under examination, much of the pathophysiology is understood (Katzenschlager and Lees 2002). Treatment of PD has progressed immensely over the decades, namely with the introduction of levodopa in the 1960s (Katzenschlager and Lees 2002). Levodopa alleviates the symptoms of PD through promotion of dopamine replacement for cells lost in the nigrostriatal pathway. However, effective administration of levodopa must be paired with a peripheral decarboxylase inhibitor (carbidopa); levodopa alone is unable to reach the endothelin receptor parenchyma in adequate amounts without assistance. In addition, despite the understanding that levodopa metabolizes into dopamine on entering the brain, using dopamine as a method of therapy is impractical because of its associated impedance of the blood–brain barrier (BBB) and the inability of dopamine to penetrate the parenchyma efficiently. The BBB is a complex homeostatic system that effectively controls and limits influx and efflux of molecules between the brain and the vascular system (Sheikov et al. 2006). Because of such factors as molecular size, hydrophobicity and atomic charge (Abbott et al. 2006), the BBB severely limits the potential for systemic administration of therapeutic agents; the system effectively excludes 98% of small-molecule drugs and nearly all large-molecule drugs (Abbott 2013).
Focused ultrasound (FUS), in combination with microbubbles, displays great potential in the ability to increase BBB permeability transiently and focally (Choi et al. 2010b; Hynynen et al. 2005; McDannold et al. 2006). The role of microbubbles is fundamental to the mechanism of BBB opening with FUS. The acoustic emissions drive the cavitating microbubbles, which in turn exert shear stress on the vessel wall (Hosseinkhah et al. 2013). The resulting shear stress is hypothesized to then disrupt the tight junction complex and allow active transport, through paracellular or transcellular endocytosis, of larger molecules, which may eventually diffuse into the brain parenchyma (Sheikov et al. 2004).Various therapeutic agents have been successfully delivered through the BBB using FUS (Baseri et al. 2012; Fan et al. 2013; Jordão et al. 2013; Park et al. 2012; Wu et al. 2014). In the case of PD treatment, neurotrophic factors were reported to protect degenerating dopaminergic neurons, as well as promote regeneration of the nigrostriatal dopamine system (Rangasamy et al. 2010). Several studies investigated the feasibility of FUS-facilitated delivery of neurotrophic factors to the brain using glia-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF) and neurturin (NTN) (Baseri et al. 2012; Wang et al. 2012). The success of this potential therapy would require repeated administration of neurotrophic factors and FUS-induced BBB opening. Therefore, the tolerability of longitudinal effects of FUS ultrasound on brain therapy is of great interest.
Several previous studies explored the effects of repeated applications of FUS for drug delivery to the brain. Yang et al. (2011) reported that repeated sonications at 20- or 40-min intervals enhanced Evans blue extravasation in rat brains. Burgess et al. (2014) performed weekly sonications for 3 wk in a mouse model of Alzheimer disease, followed by a week of behavior testing. They reported plaque reduction and increased neuronal plasticity in mice treated with three-repeated BBB opening alone. Long-term studies in non-human primates were also reported showing no significant changes in MRI (Downs et al. 2014) or histologic examination (McDannold et al. 2012). In this study, our aim was to investigate the long-term effects of repeated FUS-induced BBB opening in wild-type mice using behavioral assays and histological analysis.

br Conclusions br Conflicts of interest br


Conflicts of interest

This study was supported by the National Key Technology R&D Program (No. 2011BAI14B01) and the National Basic Research Program of China (No. 2011CB707900), the National Natural Science Fund by the Chinese National Science Foundation (No. 81127901).

Artificial heart valves and joint components, dental implants, orthopedic screws, pacemaker cases, vascular stents are commonly used biomedical applications of titanium-based implants [1]. Titanium is a bioinert metal, it induces a tolerable reaction in the host tissue, shows an adequate resistance to the corrosive in-vivo environment, and has the necessary strength, ductility and endurance limit to withstand loading experienced in everyday life [2]. Intense research is still being pursued in the development of new titanium alloys with enhanced biocompatibility and lower elastic modulus closer to bone [3]. Due to its outstanding properties, Ti and its alloys up to nowadays represent the standard in orthopedic surgery and implantology, in particular, of permanent load-bearing implants [4]. Modifications of the surface at the nanoscale have an effect on the chemical reactivity of a biomedical material affecting biomolecular, ionic and other interactions of the surface with the tissue [6]. Such changes in surface properties, altered by ultrasonic modification, may change wetting properties, leading to different protein adsorption, or influence bone mineralization [5]. Recent advances in regenerative therapies and surface science suggest, that cell adhesion to the implant surface can be regulated by various features of the underlying adhesive substrate, such as its chemical composition, physical properties, and topography (for more information about surface modification strategies and cellular recognition of these surfaces see these review papers [5,6]). Recent studies in surface nanostructuring suggest that CB-5083 manufacturer respond to nanotopography [7].
The high mechanical strength and inertness of titanium is also the main issue when trying to nanostructure it. Straight-forward known surface treatments of Ti and its alloys (Ti6Al4V) can be divided into three main groups: mechanical, chemical and physical methods [4]. Polishing, machining, blasting belong to the mechanical methods. Chemical manufacturing methods for surface modification are acid- and alkali-treatments, anodic oxidation. Physical methods can be represented by plasma spray treatment [8], ion implantation [9] and laser treatments [10]. These methods can be used either individually or in combination with other treatments, and cause the formation of different nanotopographies with inhomogeneous features. However, the majority of methods for surface nanostructuring are expensive, time consuming, or difficult to apply for large scale implant production [11]. Parameters, which are required for large-scale manufacturing, are the following: 1) ability to simultaneously reach all surfaces in devices with complex geometries (e.g. femoral stems, dental screws and cardiovascular stents); 2) possibility to modify at the nanoscale commercially available biocompatible metals and implants; 3) simple integration into industrial process lines [4]. According to the above mentioned features, chemical treatments seem to be attractive for large-scale manufacturing, because they provide uniform access of the reactive substance to all surfaces, but this leaves often unwanted residuals. In addition chemical treatment needs further processing in the case of annealing of crystalline materials at high temperatures. Thus, it is important to find an alternative technology with minimum chemicals addition for nanoscale modification of titanium, which could be applied for multifaceted devices with complex geometries such as dental screws and cardiovascular stents of potentially partially crystalline materials.
Ultrasound is used in different areas, from surface modification to capsules’ opening and diagnostics. High intensity ultrasound (HIUS) is a promising method for the production of nanostructured materials. Ultrasound is a unique energy source [12] which provides energy localization with possible acoustic cavitation phenomena, i.e., the formation, growth, and implosive collapse of cavitation bubbles in a liquid. This collapse is able to produce intense local heating (hot spots with temperatures of roughly 5000°C) and high pressures of about 500atm [12]. At the liquid-solid interface, the collapse drives high-speed jets of liquid into the surface, whose impact is sufficient to locally melt most metals [12,13] and induces significant changes in surface morphology, composition, and reactivity. On contrary to the ultrasound power used for disruption of carriers [14,15], the ultrasound power used in our study for surface modification is at least 3 times higher.

Introduction Airborne ultrasound application represents

Airborne ultrasound application represents a very promising technique because it can act without affecting the main characteristics and quality of the products [1,2]. Airborne ultrasound (US) is a cyclic sound wave and can be transferred away from the emitter across air media [3]. Ultrasound frequencies for food dehydration generally used between 20kHz and 40kHz [4–6]. The ultrasound assisted convective drying process permits the use of lower temperatures and may be useful for drying heat-sensitive materials such as fruits and vegetables [7]. The ultrasound energy can activate a series of mechanisms such as heat, diffusion, mechanical rupture, chemical effects [8], etc. The application of airborne ultrasound in convective drying is mainly linked to its mechanical effects, which can reduce the internal and/or external mass transfer resistances without producing a high amount of thermal energy during air drying [9,10]. Airborne ultrasound not only introduces pressure variations, oscillating velocities and microstreamings at gas-solid interfaces [11], but also introduces rapid series of alternating expansion and substance p cycles (sponge effect) on the internal structure [12,13], which can increase the evaporation rate of moisture, reduce the diffusion boundary layer, increase mass transfer, and accelerate diffusion [14,15]. Additionally, ultrasound could provoke cavitation of water molecules inside the solid matrix, which may be beneficial for the removal of strongly attached moisture [16,17]. Therefore, the application of airborne ultrasound can positively contribute in the air drying process. However, airborne ultrasound application and developments also have some difficulties in gas-solid systems. The main difficulty of the application of ultrasound is the transmission of the acoustic wave from the surface of emitter to the samples because the air is a high attenuating medium that absorbs the acoustic energy [18]. Moreover, the high impedance difference between the air and the solid produces reflection of a high proportion of the generated acoustic energy, preventing the acoustic energy from transferring to the solids to be treated. [19]. Therefore, it is very important to study the mechanisms of ultrasonic wave transmission in gas media in order to have a better application. At present, there are two main ways for ultrasound devices assisting food drying processes: the ultrasound transducers are directly contacted into the samples during drying (direct contact systems) [20]; the ultrasound transducers work without direct contact between the vibrating element and the samples (airborne ultrasound systems) [21]. The direct contact system permits the acoustic energy transfer from the vibrating element to the food to be improved, thus providing a higher drying rate than samples dried using hot air only. Nevertheless, the main drawback of direct contact system is quite difficult to be applied to conventional convective drying processes [22]. The airborne ultrasound system may be well adapted to conventional convective drying processes. There are different ways to apply airborne ultrasound into a convective drying system. García-Pérez et al. [23] demonstrated that the complete drying chamber can be used as an emitter. Gallego-Juárez et al. [7] presented that another approach would be to implement transducers into the drying chamber. During recent years, the application of airborne ultrasound to assist in convective drying of fruits and vegetables has been summarized in Table 1.

Airborne US dryer
Many studies showed that the application of ultrasound greatly accelerates the drying process without significantly raising material temperature (an increase of in material temperature in the range of 1–2°C) [42,43]. For this reason, the ultrasound-assisted convective drying method is useful especially for temperature-sensitive materials such as fruits and vegetables. Recently, a large number of researchers have developed some air-borne ultrasound drying systems for use in food processing.

purchase RVX-208 The proposed piezoelectric wafer may

The proposed piezoelectric wafer may be obtained by means of cutting a type of single crystal, Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT), in a special direction, shown as Fig. 1, in which [hkl] in crystallography denotes a direction and (hkl) a plane orthogonal to the direction [hkl]. The PMN–PT crystal first is orientated in a Cartesian coordinate system with crystal growth direction parallel to z axis. Then the PMN–PT crystal is poled in the [011] direction, and the wafer is cut in the plane (011). Zhang et al. [12] gives an example of this purchase RVX-208 piezoelectric constant matrix as following:where d36 is more than four times of d31 and d32. Generally, conventional d31 type piezoelectric wafer is able to excite Lamb waves (includes A0 and S0 modes) on the thin plate. Thanks to the shear deformation induced by d36, the proposed piezoelectric wafer is expected to excite both Lamb waves and shear horizontal waves.
When the piezoelectric wafer is used routinely, the direction of external electric field E is usually along the z-axis and is perpendicular to the surface of the wafer, which is bonded on the surface of plate structure. For the moment, only d36 is considered, and then Eq. (5) can be simplified as:
For a free d36 type piezoelectric wafer without in-plane external electric field and applied stress, the induced in-plane strain by applying a voltage across the z-direction can be expressed as:where is the thickness of the wafer. Fig. 1(b) shows the deformation of a d36 type piezoelectric wafer placed on the surface of a plate. The deformation can be considered due to a pair of shear strains, and . Moreover, the wafer can be equivalent to a group of line force, which is along the four edges of the wafer, applied on the plate. The induced pure shear deformation along the edges results in the guided waves in the plate.

Experimental investigations

This paper examines the fundamental characteristics of a new d36 type piezoelectric transducer, made from a PMN–PT crystal. Specifically the tuning frequency characteristics and directionality for the piezoelectric wafer are investigated in application of guided waves generation and sensing. According to the guided wave theory, the SH0 wave mode is a non-dispersive, which has many advantages for structural damage detection. The PMN–PT wafer has been demonstrated that it is capable of generating and detecting SH0 wave mode. Due to its materials anisotropy, the SH0 wave mode exhibits wave directionally. In the preliminarily FEM analyses, it proves above points based on the displacement components generated by the d36 type piezoelectric wafer, and then voltage responses show further that SH0 wave mode is dominant at 0°, but negligible small at 45°; while the A0 and S0 wave mode show the reverse trend.
Experiments were conducted to investigate both the tuning frequency characteristics and wave mode directionality for the proposed wafer. Based on wave amplitudes obtained, the following conclusions are drawn:

The financial support from the National Key Technology R&D Program under Grant No. 2011BAK02B02 & 2014BAG05B07, and the National Science Foundation of China under Grant No. 50908066 is gratefully purchase RVX-208 appreciated.

The thermal effects of delivering large amounts of acoustic energy through a focused ultrasound configuration in biological tissue (in vitro and in vivo) was first observed in 1942 [1]. Later on extensive animal studies [2] with focused ultrasound (FUS), demonstrated the reversibility of induced neurological dysfunction below certain temperature threshold and recognized the important technical and safety issues needed to overcome before employing the FUS in a clinical setting. The absence of imaging modalities capable of tissue temperature monitoring, delayed the development of FUS into a controlled, precise and safe tissue ablating therapy. The introduction of ultrasound and magnetic resonance imaging (MRI) with their fast technological advancement made image-guided focused ultrasound therapy a reality. The unsurpassed soft tissue contrast and its temperature sensitivity set MRI as the optimal imaging modality [3–5].

Before closing this section some important differences between D

Before closing this section, some important differences between 2D and 3D modeling are outlined in the context of TR near the surface of an elastic solid. The volumetric strain is chosen for the analysis since it fexofenadine hydrochloride cost has been used in previous numerical work related to fexofenadine hydrochloride cost imaging applications where the principle of TR is combined with the properties of nonlinear elasticity [23]. The volumetric strain is an eigenvector of the elasticity tensor and thus can be used to apply scalar nonlinearity laws in which, for instance, the volumetric stiffness is a power series of the volumetric strain. The volumetric strains obtained at the focal time of a TR experiment simulated with 2D and 3D models are shown in Fig. 8. In both simulations, a Ricker wavelet centered at 75kHz was used in the forward-propagation problem and the out-of-plane velocity component was focused. In 2D, the volumetric strain has a pear-like shape, which was also predicted by Janssen and Van Den Abeele [23]. It reaches two local maxima, one close to the surface where the R waves dominate and one in the bulk of the sample where the P and S waves dominate. In 3D, the volumetric strain field has the shape of a half ellipse with only one local maximum obtained on the surface of the sample and a penetration depth of only 5.3mm, for the case of a pulse centered at 75kHz. In this case, the depth profile of the volumetric strain seems to be dominated by the R waves only, which decay exponentially with depth.

This paper investigated the problem of focusing the out-of-plane velocity component on the surface of an isotropic solid sample. The numerical model used in the analysis was first validated against experimental data. Subsequently, empirical expressions for the width and depth of the focal spot (that of the out-of-plane velocity component) were found based on (i) an interpretation of Lamb’s problem to determine which waves dominate the propagation in the regions of interest (surface and bulk) and (ii) the use of the diffraction limit. In these expressions: the width of the focal spot depends only on the wavelength of the Rayleigh wave and the depth on the wavelength of the shear wave, at the center frequency of the focused pulse. The empirical expressions were found to be robust to changes of the center frequency of the focused pulse and of the Poisson’s ratio of the material. The problem studied in this paper is of interest in a number of NDT applications. In the experiments conducted recently by the authors [7], it is now sufficient to measure the size of the TR focal spot on the surface of the sample to infer how deep the sample is probed.

This work was funded by the U.S. Dept. of Energy, Fuel Cycle R&D, Used Fuel Disposition (Storage) campaign.

Ultrasound contrast agents (UCAs) were developed to enhance the visibility of the blood pool during ultrasound imaging which allows physicians to discern internal organs and to resolve small blood vessels [3]. The development of these contrast agents has gone through several generations leading to significant improvements in image quality over the last two decades [4]. The first generation of UCAs consists of an air bubble encapsulated by a fatty acid or protein shell [5]. Microbubble stabilization techniques improved with the second generation of UCAs developed during the 1990s when the gas core of the microbubble transitioned from air to low solubility gases for increased longevity [6,7]. Microbubble coatings also progress with the introduction of phospholipid and polymer shells, or a blend of both [8]. The encapsulation material preserves the microbubble through added resistance against surface tension-driven dissolution in aqueous fluids [9]. The use of these second generation phospholipid-coated microbubbles as UCAs is gaining considerable attention in the medical field because of the thin (2–3nm) and highly elastic shell [10]. The third generation consists of encapsulated microbubbles whose shells contain special targeting properties [11].