Acoustic Shock Waves Research Articles

Connectivity between the solar photosphere and chromosphere in a vortical structure

Context. High-resolution solar observations have revealed the existence of small-scale vortices, as seen in chromospheric intensity maps and velocity diagnostics. Frequently, these vortices have been observed near magnetic flux concentrations, indicating a link between swirls and the evolution of the small-scale magnetic fields. Vortices have also been studied with magneto-hydrodynamic (MHD) numerical simulations of the solar atmosphere, revealing their complexity, dynamics, and magnetic nature. In particular, it has been proposed that a rotating magnetic field structure driven by a photospheric vortex flow at its footprint produces the chromospheric swirling plasma motion. Aims. We present a complete and comprehensive description of the time evolution of a small-scale magnetic flux concentration interacting with the intergranular vortex flow and affected by processes of intensification and weakening of its magnetic field. In addition, we study the chromospheric dynamics associated with the interaction, including the analysis of a chromospheric swirl and an impulsive chromospheric jet. Methods. We studied observations taken with the CRisp Imaging SpectroPolarimeter (CRISP) instrument and the CHROMospheric Imaging Spectrometer (CHROMIS) at the Swedish Solar Telescope (SST) in April 2019. The data were recorded at quiet-Sun disc centre, consisting of full Stokes maps in the Fe I line at 6173 Å and in the Ca II infrared triplet line at 8542 Å, as well as spectroscopic maps in the lines of Hα 6563 Å and Ca II K 3934 Å. Utilising the multi-wavelength data and performing height-dependent Stokes inversion, based on methods of local correlation tracking and wavelet analysis, we studied several atmospheric properties during the event lifetime. This approach allowed us to interpret the spatial and temporal connectivity between the photosphere and the chromosphere. Results. We identified the convective collapse process as the initial mechanism of magnetic field intensification, generating a re-bound flow moving upwards within the magnetic flux concentration. This disturbance eventually steepens into an acoustic shock wave that dissipates in the lower chromosphere, heating it locally. We observed prolonged magnetic field amplification when the vortex flow disappears during the propagation of the upward velocity disturbance. We propose that this type of magnetic field amplification could be attributed to changes in the local vorticity. Our analysis indicates the rotation of a magnetic structure that extends from the photosphere to the chromosphere, anchored to a photospheric magnetic flux concentration. It appears to be affected by a propagating shock wave and its subsequent dissipation process could be related to the release of the jet.

Acoustic shock wave-induced sp2-to-sp3-type phase transition-part II: Evidence of the presence of diamond from valance band spectra and electronic diffraction pattern

Here, we introduce a novel technique that utilizes repeated exposure to low-pressure (2.0 MPa) millisecond acoustic shock waves on a graphite sample to facilitate the successful transformation of graphite into diamond. This transformation is based on a martensitic nucleation mechanism verified through valance-band X-ray photoelectron spectroscopic and electron diffraction observations. Typically, diamond formation occurs only under pressures of 50–60 GPa or more in nanosecond dynamic compression experiments. The present work offers a new platform to make synthetic diamonds and a new scientific path for diamond formation.

Investigation of bismuth selenide’s structural stability and tunable bandgap under exposure to acoustic shock waves for solar cell and aerospace applications

Bismuth selenide is a promising semiconductor for optoelectronics and energy conversion, including solar cells and aerospace applications. However, it degrades at high temperatures, affecting stability. According to the previous literature, we can solve this problem and easily tune under high pressure, but no reports are available for response against acoustic shock waves. To explore this, commercially available Bi2Se3 was purchased and tested under acoustic shock wave exposure. Bi2Se3 was subjected to 100, 200, 300, and 400 acoustic shock waves with 0.59 MPa transient pressure at 520 K temperature and 1.5 Mach number. Before and after shock-loaded Bi2Se3 samples were characterized using XRD, Raman, UV-DRS, PL, and FE- SEM and EDX. Under acoustic shock waves, Bi2Se3 exhibits increased crystallite size and reduced strain rate, promoting good thermal stability. It also shows a smaller bandgap and enhanced PL intensity, which ensures efficient solar cell operation. As a result, the material demonstrates improved thermal insulation and durability, which are crucial for stability and protection in extreme conditions for aerospace applications. These improvements make Bi2Se3 more suitable for solar cell and aerospace applications.

Effects of acoustic shock waves on the structural and optical properties of cadmium borate

Cadmium borate (CdB₂O₄), an inorganic compound combining transition metals and non-metals, has a broad range of optical applications. In this study, CdB₂O₄ was subjected to acoustic transient pressure using a semi-automatic Reddy tube, with shock pulses applied at counts of 100, 200, 300, and 400 at a Mach number of 1.5, corresponding to a transient pressure of 0.59 MPa and a temperature of 520 K. Control and shock-treated samples were analyzed using XRD, Raman, FTIR, SEM, UV-DRS, and photoluminescence spectroscopy to investigate shock wave effects. The XRD analysis revealed peak disappearance, the formation of new peaks, increased crystallinity, and instability in crystallite size. Raman spectroscopy showed peak disappearance, shifts, and broadening of lattice modes. SEM indicated increased particle size and agglomeration under shock conditions, consistent with changes in crystallinity. UV-DRS analysis shows a slight change in their band gap. Photoluminescence exhibited fluctuating trends in luminescent properties after the shock treatment. The findings reveal that CdB₂O₄'s structural and optical properties are sensitive to acoustic pressure, suggesting its potential for tailored optical behavior in specific applications. These results enhance our understanding of how acoustic pressure affects CdB₂O₄ and open new possibilities for optimizing its use in high-pressure applications.

Excitation of ion acoustic solitary waves and shock waves in decaying plasma between biased parallel-plate electrodes

In this study, we explore the excitation of ion acoustic solitary waves and shock waves in a decaying plasma confined between biased parallel-plate electrodes using one-dimensional particle-in-cell simulations. Our findings demonstrate that the oscillating electric field at the sheath edge generates a sequence of ion acoustic solitary waves, which exhibit characteristics consistent with the Korteweg–de Vries (KdV) equations. We observe that as the electron temperature decreases, the intervals between adjacent wave pulses shorten progressively, leading to the eventual formation of a coherent shock wave structure. These findings highlight the critical role of kinetic simulations in elucidating the dynamics of plasma decay processes.

Detection of near- and far-field traveling ionospheric disturbances during Tsunami Events over South Pacific

Large earthquakes and tsunamis often occur around the Pacific Ring of Fire, in which Traveling Ionospheric Disturbances (TIDs) have been observed after these events. Sometimes (depending on seismic source features), TIDs can be observed near the epicenter of the generated earthquake due to the shock-acoustic wave. Additionally, TIDs can be induced by tsunamis due to the generated gravity waves and be detected several thousand kilometers away from the source. TIDs can be detected by analyzing Total Electron Content (TEC), which is calculated, indirectly, using signals from Global Navigation Satellite System (GNSS) receivers. The procedure allows for studying the ionospheric disturbance with a good spatial and temporal resolution. This study aims to identify tsunami-induced TIDs in the near- and far-fields following significant events in the Oriental and Occidental South Pacific Ocean. The selection criteria covering 14 tsunamis that occurred between 2010 and 2021 generated by earthquakes with Mw ⩾7.8 and depth less than 50 km. Tsunamis were modeled and compared with the TIDs obtained from TEC deviations. Near-field and far-field TIDs observed in hodochrons differ primarily in the clarity of their association with tsunamis. The simulated tidal gauges show a possible connection with the observed TEC anomalies, behaving similarly but with different delay times, showing some events even hours in advance. This potential correlation between TID parameters and tsunamis propagated in the Pacific Ocean can contribute to understanding the involved mechanisms and facilitate the development of near real-time early warning systems.

Acoustic Shock Wave-Induced Rutile to Anatase Phase Transition of TiO2 Nanoparticles and Exploration of Their Unconventional Thermodynamic Structural Transition Path of Crystallization Behaviors.

Titanium dioxide (TiO2) is one of the most well-known and long-standing polymorphic materials in the transition metal oxide group of materials. The transition from rutile to anatase is one of the long-standing fundamental questions among materials science researchers because seeking the nucleation site at the beginning of the phase transition is highly challenging. Until now, there have been no studies on the unconventional structural phase transition of TiO2 nanoparticles by acoustic shock waves. In the present study, this work provides the first evidence on the solid-state nanostructure of the rutile-to-anatase phase transition of TiO2 by acoustic shock waves whereby these phase transition results are evaluated by Raman spectroscopy, thermal calorimetry, X-ray photoelectron spectroscopy, and microscopic techniques. We propose a novel mechanism for the occurrence of the rutile-to-anatase phase transition based on thermophysical properties and shock wave-induced melting concepts. Under shocked conditions, the R-A phase transition occurs because of the anatase phase's lower interfacial energy (γL/A) and surface energy compared to rutile. We strongly believe that the present work can provide in-depth insight into understanding the crystallization concepts of the TiO2 NPs under extreme conditions, especially with regard to the rutile-to-anatase phase transition.

Scalable production of siRNA-encapsulated extracellular vesicles for the inhibition of KRAS-mutant cancer using acoustic shock waves.

Extracellular vesicles (EVs) have emerged as a potential delivery vehicle for nucleic-acid-based therapeutics, but challenges related to their large-scale production and cargo-loading efficiency have limited their therapeutic potential. To address these issues, we developed a novel "shock wave extracellular vesicles engineering technology" (SWEET) as a non-genetic, scalable manufacturing strategy that uses shock waves (SWs) to encapsulate siRNAs in EVs. Here, we describe the use of the SWEET platform to load large quantities of KRASG12C-targeting siRNA into small bovine-milk-derived EVs (sBMEVs), with high efficiency. The siRNA-loaded sBMEVs effectively silenced oncogenic KRASG12C expression in cancer cells; they inhibited tumour growth when administered intravenously in a non-small cell lung cancer xenograft mouse model. Our study demonstrates the potential for the SWEET platform to serve as a novel method that allows large-scale production of cargo-loaded EVs for use in a wide range of therapeutic applications.

Acoustic waves and smart biomimetic nanoparticles: combination treatment from 2D to 3D colorectal cancer models

Colorectal Cancer (CRC) is the second leading cause of death among tumors worldwide. Conventional treatments are often accompanied by emerging immunotherapies, trying to reduce the burden of advanced and metastatic stages. Recently, nanomedicine therapies have been under intensive research to offer new perspectives to patients. Motivated by this rationale, this work proposes the formulation of advanced biomimetic and targeted nanoparticles (NPs) enabling a stimuli responsive and localized therapy, triggered by the safe use of acoustic shockwaves, a deep-penetrating tissue stimulation. Iron-doped zinc oxide nanocrystals were synthetized and enveloped in a biomimetic lipid bilayer shell, conjugating a peptide (YSA) as selective targeting toward CRC cells. Comparative studies, performed both in 2D monolayer and 3D spheroids of CRC models, between non-targeted (L-ZnO) and targeted (YSA-L-ZnO) nanoparticles demonstrated the superior capability of targeted nanosystems to dock and be internalized by CRC cells. The YSA-L-ZnO are proven to be highly biocompatible and hemocompatible, and capable of inducing selective damage, once activated by safe shockwaves. This mechanism is able to synergistically ablate tumor cells in both 2D and 3D models, proofing the concept of an innovative stimuli-responsive nanomedicine with a targeted and biomimetic strategy to offer future options for cancer fight.Graphical

Artificial shock wave impact studies on Olivine single crystal - A Raman spectroscopic approach

After the invention of indoor tabletop shock tubes, studies on the impact of low-pressure acoustic shock waves on materials have been sufficiently conducted and found several spectacular phase transitions. However, the acoustic shock wave impact studies on minerals remain unexplored. The floodgates are to be opened by streamlining a systematic approach in bringing out a new era of spectacular findings as more and more minerals are involved in the investigation. Hence, in the present investigation, we have chosen one of the most prominent upper mantle earth minerals of α-Olivine (forsterite-Mg2SiO4) single crystal for the ex-situ shock wave recovery experiment with 2.0 MPa transient pressure. Raman spectroscopic technique has been utilized to examine the crystallographic stability of the title mineral. The observed shock-wave impact results demonstrate that the forsterite remains to be in the crystallized state maintaining the same space group of Pbnm, however, significant changes have been witnessed in the normalized intensity ratio of the characteristic doublet Raman peaks of the forsterite (asymmetry stretching SiO4 (824 cm−1)/symmetry stretching SiO4 (855 cm−1) such that the values are found to be 2.17, 2.27, 1.38, 0.51, and 2.43 against the number of shock pulses of 0, 1, 2, 3 and 4, respectively. It is to be noted that, we have found more pronounced changes in the doublet Raman peak intensity compared to the flat plate accelerator shock compression experiment on forsterite (Tielke et al., J. Geophys. Res. Planets (2022)) and the observed values are 0.8, 0.3, 0.6, 0.8 and 0.52 for 0, 21.3, 22.4, 38.9 and 41.8 GPa, respectively without undergoing any structural transitions towards the high-pressure phases. Based on the assessment of comparative results, tabletop shock-tubes can be strongly considered for mineralogical research to expand the current knowledge on the behaviors of the earth and space minerals under extreme-conditions.

Dust acoustic nonlinearity of nonlinear mode in plasma to compute temporal and spatial results

Our manuscript is related to use Caputo fractional order derivative (CFOD) to investigate results of non-linear mode in plasma. We establish results for both temporal and spatial approximate solution. For the require results, we use reduction perturbation method (RPM) to find the analytical solution of the dust acoustic shock waves. Further, using the same technique we find the solitary wave potential and compared the solutions obtained with another very useful technique known as Homotopy perturbation method (HPM). The comparison of results for both approaches are more precise and agreed with the exact solution of the problem. Finally, we present graphical representation for different fractional order for both temporal and spatial approximate solution.

Analysis of the damage effects of carbon fiber composites under the mechanical impact loads of lightning based on a modified simulation calculation method

Mechanical effects contribute significantly to the multiphysical damage of carbon fiber-reinforced polymer (CFRP) composites induced by high-amplitude impulse lightning currents. In this paper, the mechanical impact loads (MILs) of lightning are decomposed into acoustic shock waves from arc channel expansion (AESW), electromagnetic force (EMF), and shockwave overpressure from surface explosion (SESW). A 3D finite element mechanical damage model of laminates was established based on the Hashin–Yeh initial creation and modified stiffness degradation matrix. The model was verified by comparison with pure mechanical impacts. The dynamic response and damage modes of laminates subjected to AESW, EMF, SESW, and MILs were studied and compared. The MILs are exponentially related to the current intensity. The damage effect of laminates under MILs is inversely related to the impact radius. The comparison shows that the effect of the EMF gradually exceeds that of the AESW as the current peak increases and its value is approximately twice that of the latter when the current peak Ip exceeds 165 kA. In contrast, SESW is the primary cause of the damage effect. Over 70 % of the deformation contribution to laminates under MILs comes from SESW (Ip = 165 kA). Furthermore, the strongest SESW is induced by the insufficient thermal conductivity of the CFRP laminates.

(101) SHOCKWAVE THERAPY FOR THE TREATMENT OF POSTPARTUM STRESS URINARY INCONTINENCE: A PILOT STUDY

Abstract Introduction Stress urinary incontinence (SUI) is estimated to affect approximately 15% of adult women. Low-intensity extracorporeal shock wave therapy (Li-ESWT) is a form of electrohydraulic acoustic shockwave that has been shown to be effective in animal models of SUI. The Urogold100® is a Li-ESWT device that is FDA-cleared for improving blood flow, connective tissue activation, and pain relief, and it has been shown in multiple studies to be effective for mild to moderate erectile dysfunction and chronic pelvic pain in both men and women. While Li-ESWT has been investigated for related urologic conditions, minimal research exists as to its potential effectiveness for SUI in women. Objective Our aim was to evaluate the effectiveness of Li-ESWT for women with postpartum stress urinary incontinence in a pilot study. Methods Email recruitment was carried out in a single sexual medicine practice. Four women underwent weekly treatments with Li-ESWT for 4-6 weeks. All patients were postpartum women between ages 43-55. Treatment specifics included 1000 shocks at 2.5 Hz (initial visit) and 3.0 Hz (subsequent visits) distributed over the perineum and urethral opening. Energy level was based on patient tolerance, beginning with 0.06 Mj/mm2 and increased up to 0.08 Mj/mm2 for subsequent visits. Evaluation measures included the International Consultation on Incontinence Questionnaire Short Form (ICIQ-SF) and National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Bladder Diary, both administered prior to treatment initiation and after treatment completion. The ICIQ-SF allowed patients to self-assess their urine leakage over the past several weeks (amount and frequency) while the Bladder Diary required patients to record specific leakage incidences throughout a single day. Results Prior to treatment initiation, patients reported 1-3 small daily urine leaks via the NIDDK Bladder Diary. All patients either improved or remained the same in this assessment post-treatment; all patients reported 1 small daily leak after treatment completion. Results from the subjective ICIQ-SF varied: 1 patient reported worsening from 1 daily leak to 2-3 daily leaks, which she attributed to increased water intake. Two patients reported improvements (several daily leaks to 1 weekly leak; several daily leaks to 2-3 weekly leaks). One patient reported no change. Subjective reporting from patients indicated 3 of the 4 felt the treatment was improving their symptoms, and the fourth patient reported no changes. Conclusions Our pilot study indicates that 3 of 4 patients showed improvements in their objective Bladder Diary recordings with reduced frequency of urine leakage, and 2 of 4 patients noted improvements in their subjective ICIQ-SF reporting. 3 of 4 provided positive verbal feedback as well. Despite the limited sample size, the improvements seen in the objective leakage frequency recordings are encouraging findings that warrant future investigation in a larger cohort. Given the noninvasive nature, ease of use, and high patient tolerability of Li-ESWT, this treatment modality should be considered for investigation in a larger cohort with the goal of relieving symptoms of SUI. Disclosure No.

Assessment of acoustic shock wave resistance of SiO2 (α-cristobalite): A potential material for aerospace and defense industry applications

In the present research article, the acoustic shock wave-resistant efficiency of silica microparticles (SiO2-α-cristobalite)) has been experimentally evaluated in terms of structural, optical and morphological stability against the impact of shock waves. The required SiO2 particles were synthesized by a hydrothermal method which was subjected to a different number of shock pulses such as 200,400 and 600 with Mach number 2.2. Shocked samples’ structural, morphological and optical stabilities have been evaluated by utilizing a powder X-ray diffractometer (PXRD), Ultraviolet–Diffuse reflectance spectrometer (DRS) while the surface morphological analysis has been scrutinized by the field emission scanning electron microscopic technique (FESEM) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy techniques are utilized to evaluate oxidation states and crystallographic structural stability. The above-mentioned analytical techniques provide convincing proofs whereby the synthesized SiO2 particles are authentically proven to possess outstanding structural, optical and morphological stability against the impact of shock waves. The implicated experimental results and the arguments strongly suggest that the SiO2 particles are suitable candidates for aerospace and defense industry applications due to their outstanding shock wave-resistant properties.

Effects of dust size distribution and non-Maxwellian electrons on shock waves in a dusty plasma

We present a study of dust acoustic shock waves in a non-Maxwellian plasma with dust charge fluctuations, which are seen to cause a dissipation term in fluid model, and consequently shocks are generated. In particular, we focus on dust acoustic waves as affected by various dust size distributions. Two distinct dust size distributions—the polynomial and the power law distributions—have been used. For analytical investigation of nonlinear wave propagation in complex plasmas, a reductive perturbation approach is used to obtain the Burgers equation. A dusty plasma system with non-Maxwellian Kappa distribution is considered and it is shown that the amplitude of a shock wave, for the dust size distribution is larger than that for the mono-sized counterpart, while the shock width manifests an opposite trend. Furthermore, the shock wave speed is also affected by the dust size distributions as well as by the nature of velocity distribution function. To benchmark our findings, we apply the proper limit on the spectral index, i.e., κ→∞, and retrieve the Maxwellian results. The current findings are crucial for comprehending respective shock distributions for a plasma system exhibiting non-thermal characteristics and having dust size distributions.

Acoustic shock wave induced chemical reactions–A case study of NaCl single crystal

Herein, we report the catalytic-free acoustic shock wave-induced synthesis of the non-stoichiometry compound of sodium chloride (Na3Cl2-P4/m) from the stoichiometry NaCl (B1). The shocked NaCl crystal structure is formed as a mixed phase together with the NaCl (B1) and (Na3Cl2-P4/m) thereby the formation of non-stoichiometry compound of Na3Cl2 is confirmed by the diffraction, vibrational, spectroscopic and microscopic techniques. X-ray photoelectron spectroscopic study reveals the positive energy shift of Na 1 s peak which confirms the formation of higher coordination number Na3Cl2 (six to eight) such that it can be considered as Na rich structure. The typical cubic morphology has changed into butterfly wing structure under shocked conditions which is found to be novel, to date. Due to the formation of Na-rich crystal structure, the electrical properties of the shocked crystal are greatly altered. The maximum values of the real part of the impedance of the control and shocked crystals are 1.9 × 107 ohm and 1.0 × 107 ohm, respectively at the lower frequency regions. The present study offers a new platform to synthesize the stable non-stoichiometry NaCl structures under ambient conditions by low pressure acoustic shock waves which could bring about new understanding and implications on NaCl crystals and their applications.

Core-shell diamond-graphene needles with silicon-vacancy color centers

Color centers in diamond nanostructures open new horizons in biomedicine, offering a biocompatible material platform for sensing temperature, pH, and magnetic field. Covering of the color centers enriched diamonds with graphene shell can essentially extend their application potential. Specifically, under irradiation with ultrashort laser pulses, the highly absorptive graphene shell can be used for excitation of a shock acoustic wave which can be used for cancer cell destruction or drug photoactivation through the Joule heating. In this study, we present a novel method for creating diamond-graphite core-shell structures. Through precise control of the growth of the graphitic layer on Single Crystal Diamond Needles (SCDNs) via vacuum annealing at 900°C for 30 minutes, we preserved 57% of the light emission from silicon-vacancy (SiV-) centers while maintaining their spectral peaks. Contrary to our expectations of reduced SiV- luminescence due to the presence of the graphitic shell, we observed that the initial high brightness of SiV- in the diamond needles persisted. This enabled us to detect SiV- luminescence spectrally, even within the core-shell structures. Our results underscore the tunability of these structures’ properties through temperature and duration control, suggesting promising prospects for their application in advanced biomedical tools with sensing capabilities.

Acoustic shock wave processing on amorphous carbon quantum dots – correlation between spectroscopic-morphological–magnetic and electrical conductivity properties

In this context, we report the acoustic shock wave processing on amorphous Carbon quantum dots (a-CQD) such that its degree of graphitization and magnetic properties are analyzed. Analytical techniques such as the Raman spectrometer, high resonation–transmission electron microscopy (HR-TEM) and vibrating sample magnetometer (VSM) are utilized to understand the structural, morphological and magnetic properties changes under shocked conditions. The Raman spectroscopic data reveal that the ID/IG ratio is slightly reduced under shocked conditions and the observed values are 0.78, 0.77 and 0.75 for the respective 0, 150 and 300 shocked conditions. The formation of ultra-short-range graphitic nanostructures is confirmed by HR-TEM results at the 300-shocked condition. The most convincing and supporting results for the enhancement of the degree of graphitization are found by the outcome of the magnetic properties such that the saturation magnetization (Ms) is found to be linearly reduced with respect to the number of shock pulses and the observed values are 0.869, 0.757 and 0.710 emu/g for the 0, 150 and 300 shocked conditions, respectively. The electrical resistance of the a-CQD is found to be linearly reduced with respect to the number of shock pulses due to the reduction of sp3 carbon networks. The formation of crystalline graphitic nanostructures in amorphous CQD is explained on the basis of the hot-spot nucleation mechanism. Based on the obtained Raman, HR-TEM and VSM results, during the shocked conditions, slight enhancement of the graphitization is observed; however, from the structural stability point of view, the Carbon dots have high shock resistance than that of the amorphous carbon nanoparticles, multi-wall carbon nanotubes, and reduced graphene oxide nanoparticles. Hence, the title quantum dots can be strongly considered for the applications of device fabrication.

Synthesis of crystalline graphite from disordered graphite by acoustic shock waves: Hot-spot nucleation approach

The existence of the long-range order under extreme conditions is a highly unusual structural concept that remains one of the top-class fundamental questions for every high-pressure researcher to resolve. In the present study, it is probably the first time that we report the acoustical shock wave-induced conversion from disordered graphite (ID/IG- 0.709) to highly-ordered graphite (ID/IG- 0.251) at the 750-shocked condition and the obtained long-range ordering is comprehensively examined by a few representative microscopic observations which include the Raman spectroscopy, photoelectric X-ray spectrometry and transmission electronic microscopy. Furthermore, the shock wave-induced hot-spot nucleation mechanism for the graphitization is put forward in combination with the outcome of the obtained magnetic, electrical and thermal experimental data. All of these acquired results clearly demonstrate that by using the acoustical shock waves, it is possible to provide one distinctive insight into deeply disclosing the large-scale synthesis of crystalline graphite, which has the potential to be utilized extensively in future commercial applications.

Coronary intravascular lithotripsy in contemporary practice: challenges and opportunities in coronary intervention.

Percutaneous coronary intervention (PCI) of calcified coronary arteries is associated with poor outcomes. Poorly modified calcified lesion hinders the stent delivery, disrupts drug-carrying polymer, impairs drug elution kinetics and results in under-expanded stent (UES). UES is the most common cause of acute stent thrombosis and in-stent restenosis after PCI of calcified lesions. Angiography has poor sensitivity for recognition and quantification of coronary calcium, thereby mandating the use of intravascular imaging. Intravascular imaging, like intravascular ultrasound and optical coherence tomography, has the potential to accurately identify and quantify the coronary calcium and to guide appropriate modification device before stent placement. Available options for the modification of calcified plaque include modified balloons (cutting balloon, scoring balloon and high-pressure balloon), atherectomy devices (rotational atherectomy and orbital atherectomy) and laser atherectomy. Coronary intravascular lithotripsy (IVL) is the newest addition to the tool box for calcified plaque modification. It produces the acoustic shockwaves, which interact with the coronary calcium to cause multiplanar fractures. These calcium fractures increase the vessel compliance and result in desirable minimum stent areas. Coronary IVL has established its safety and efficacy for calcified lesion in series of Disrupt CAD trials. Its advantages over atherectomy devices include ease of use on workhorse wire, ability to modify deep calcium, no debris embolization causing slow flow or no-flow and minimal thermal injury. It is showing promising results in modification of difficult calcified lesion subsets such as calcified nodule, calcified left main bifurcation lesions and chronic total occlusion. In this review, authors will summarize the mechanism of action for IVL, its role in contemporary practice, evidence available for its use, its advantages over atherectomy devices and its imaging insight in different calcified lesion scenarios.