Microvascularization of the human central and peripheral nervous system: A new microcomputed tomography method.

Microcomputed X-ray tomography (microCT), developed since the late 1990s, is a miniaturized version of the tomographs used daily in medical imaging. It produces vascular images that are different from those obtained by microradiography, in particular by facilitating the vision in space, thus understanding microvascularisation. The anatomical specimens, once treated with formalin, are injected with a mixture made of gelatin containing a contrast product (barium) and then analyzed by microCT. The acquisition times that can exceed 24hours and metal sheets used for X-ray filtering vary according to the sample. The projection images are reconstructed to produce 2D sections. These are combined for the reconstruction of 3D models using a volume rendering software. Four examples will allow the imaging of microvascularization: the inferior alveolar nerve, the cerebral cortex and pia-mother, brain stem, central gray nuclei (ganglia at the base of the brain). Small capillaries are highlighted using high-end software for reconstruction. Conventional software or freeware cause a considerable loss of information on small vessels that are not visualized. The VGStudio max high-end software allows the production of videos that are particularly useful for 3D exploration and teaching (four videos are provided with this article).

Multiple light scattering in metallic ejecta produced under intense shockwave compression.

A roughened metallic plate, subjected to intense shock wave compression, gives rise to an expanding ejecta particle cloud. Photonic Doppler velocimetry (PDV), a fiber-based heterodyne velocimeter, is often used to track ejecta velocities in dynamic compression experiments and on nanosecond time scales. Shortly after shock breakout at the metal-vacuum interface, a particular feature observed in many experiments in the velocity spectrograms is what appear to be slow-moving ejecta, below the free-surface velocity. Using Doppler Monte Carlo simulations incorporating the transport of polarization in the ejecta, we show that this feature is likely to be explained by the multiple scattering of light, rather than by possible collisions among particles, slowing down the ejecta. As the cloud expands in a vacuum, the contribution of multiple scattering decreases due to the limited field of view of the pigtailed collimator used to probe the ejecta, showing that the whole geometry of the system must be taken into account in the calculations to interpret and predict PDV measurements.

Microcomputed tomography (microCT) and histology of the mandibular canal in human and laboratory animals.

The inferior alveolar nerve (IAN) is a sensitive branch of the trigeminal nerve. It has an intra-bone path in the mandible, inside the mandibular canal, where it is accompanied by lymph, venous and arterial vessels. We have studied the mandibular canal in human mandibles and in some laboratory animals (mice, rats, rabbits and cats). Microcomputed tomography evidenced that the walls of the canal are made with thin plates of trabecular bone with numerous fenestrations. This aspect is evidenced in dentate subjects and become more evident in edentulous subjects with atrophy of the alveolar bone. In rats and mice, the wall of the canal is also clearly composed of trabecular plates coming from the surrounding alveolar bone of the mandible. In the rabbit, similar findings are also observed but the trajectory of the canal is more difficult to identify. In the cat, the floor of the canal is composed of the cortical bone from the basilar cortex of the mandible and the roof has a trabecular nature. Vascular injections of gelatin-barium evidenced the arterial trajectories inside the bone in rats and humans. Undecalcified bone sections in human evidenced the histological aspect of the IAN and its connective sheets. Some nervous bundles can be observed outside the epineurium. Bone remodeling is observed on the wall of the mandibular canal. These descriptive findings have a clinical relevance in dental implantology or mandibular surgery.

Characterization of Staphylococcus caprae Clinical Isolates Involved in Human Bone and Joint Infections, Compared with Goat Mastitis Isolates.

Staphylococcus caprae is an emerging microorganism in human bone and joint infections (BJI). The aim of this study is to describe the features of S. caprae isolates involved in BJI (H for human) compared with those of isolates recovered in goat mastitis (A for animal). Fourteen isolates of each origin were included. Identifications were performed using a Vitek 2 GP ID card, tuf gene sequencing, and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) Vitek MS. Molecular typing was carried out using pulsed-field gel electrophoresis (PFGE) and DiversiLab technology. The crystal violet method was used to determine biofilm-forming ability. Virulence factors were searched by PCR. Vitek MS technology provides an accurate identification for the two types of isolates compared to that of gold-standard sequencing (sensitivity, 96.4%), whereas the Vitek 2 GP ID card was more effective for H isolates. Molecular typing methods revealed two distinct lineages corresponding to the origin despite few overlaps: H and A. In our experimental conditions, no significant difference was observed in biofilm production ability between H and A isolates. Nine isolates (5 H isolates and 4 A isolates) behaved as weak producers while one A isolate was a strong producer. Concerning virulence factors, the autolysin atlC and the serine aspartate adhesin (sdrZ) genes were detected in 24 isolates (86%), whereas the lipase gene was always detected, except in one H isolate (96%). The ica operon was present in 23 isolates (82%). Fibrinogen-binding (fbe) or collagen-binding (cna) genes were not detected by using primers designed for Staphylococcus aureus or Staphylococcus epidermidis, even in low stringency conditions. Although S. caprae probably remains underestimated in human infections, further studies are needed to better understand the evolution and the adaptation of this species to its host.

Representing virus-host interactions and other multi-organism processes in the Gene Ontology.

BACKGROUND: The Gene Ontology project is a collaborative effort to provide descriptions of gene products in a consistent and computable language, and in a species-independent manner. The Gene Ontology is designed to be applicable to all organisms but up to now has been largely under-utilized for prokaryotes and viruses, in part because of a lack of appropriate ontology terms. METHODS: To address this issue, we have developed a set of Gene Ontology classes that are applicable to microbes and their hosts, improving both coverage and quality in this area of the Gene Ontology. Describing microbial and viral gene products brings with it the additional challenge of capturing both the host and the microbe. Recognising this, we have worked closely with annotation groups to test and optimize the GO classes, and we describe here a set of annotation guidelines that allow the controlled description of two interacting organisms. CONCLUSIONS: Building on the microbial resources already in existence such as ViralZone, UniProtKB keywords and MeGO, this project provides an integrated ontology to describe interactions between microbial species and their hosts, with mappings to the external resources above. Housing this information within the freely-accessible Gene Ontology project allows the classes and annotation structure to be utilized by a large community of biologists and users.

112 What's your emergency? Overview of mental health and sleep disorders among emergency medical dispatchers in a French 112 call center.

BACKGROUND: Emergency medical dispatchers (EMD) experience significant occupational stress. Medical dispatching includes call-taking, triage, dispatch, and providing callers gesture guidance to the victims. Every decision has a major impact on the patient's outcome. Chronic exposure to stress and potentially traumatic situations, combined with night shifts can impact the stress response and physical health of staff. OBJECTIVES: To evaluate the prevalence of mental health and sleep disorders among EMD personnel working in a 112-call center, prior to an evidence-based prevention intervention (primary outcome); and to assess the relationship between health outcomes and DM (secondary outcome). METHODS: We conducted a descriptive, monocentric study with 109 EMD. HAD Anxiety (HAD-A) and Depression (HAD-D) scores, and the PTSD checklist for DSM-5 (PCL-5) were used to explore mental health disorders. The Epworth Sleepiness Scale, and other analog scales were used to explore sleep disorders. DM resources were assessed using the Freiburg Mindfulness Inventory (FMI), and its Presence and Acceptance subscales. RESULTS: A total of 72% of the EMD working in the call center were included. Of these, 16.6% had moderate anxiety disorder, and 6.4% had an anxiety disorder (Mean HAD-A: 6.05 ± 2.88). Furthermore, 16.6% had a moderate depression disorder, and 6.4% had a depression disorder (Mean HAD-D: 4.28 ± 3.28), and 16% had symptoms of PTSD (Mean PCL-5: 17.57 ± 13.67). Turning to sleep, 39% may suffer from excessive daytime sleepiness (EDS), and 10% had confirmed EDS (Mean Epworth score 10.47 ± 4.41). Finally, 39% had moderate insomnia, and 59% had severe insomnia (Mean insomnia: 13.84 ± 5.77.). Medium-strength negative correlations were found between mental health and DM (FMI scores and sub-scores: -0.48 < r < - 0.29; 0.001 < p < 0.004); and a positive correlation was found between DM and daytime awareness (0.22 < r < 0.26; 0.01 < p < 0.03). CONCLUSION: The prevalence of depression, symptoms of PTSD, and sleep disorders in our sample of EMD is significant, and confirms findings reported in the literature. The EMD population may benefit from specific, multi-level interventions that target mindfulness, sleep, and ergonomics to improve their mental and physical health.

[Anatomical study of the superficial cervical plexus: application to the prevention of the postoperative sensitive facial deficits]. / Étude anatomique du plexus cervical superficiel: application à la prévention des déficits sensitifs faciaux postopératoires.

INTRODUCTION: The cervical surgery can be complicated of postoperative facial sensory deficits, in particular in using the anterior presternocleidomastoid approach. The purpose of this study was to specify the routes and the links of nerves involved in these sensory deficits (great auricular nerve and transverse cervical nerve with the goal, to deducing, if possible, some modifications of the surgical practices to prevent the deficits. PATIENTS: Ten dissections of the superficial cervical plexus, on preserved anatomical subjects, were made from February till May 2009. Nerves and whole superficial venous network were dissected on all along their route to be able to make several measures of distances and angles. All the data were computerized treated by spreadsheet. RESULTS: The transverse cervical nerve appeared from the posterior edge of the sternocleidomasoid (SCM) muscle in 7.46 ± 1.81 cm s (5,1-10,0) of the clavicle, with an angle of 108.3 ± 8.15° (93-120). Its halving terminal branches was made in 2.92 ± 1.76 cm s (0,4-5,2) of the posterior edge of the SCM muscle, with an angle between these two branches of 74.0 ± 36.8° (40-120). The great auricular nerve appeared from the posterior edge of the muscle SCM in 8.96 ± 1.85 cm (6.4-12.0) of the clavicle, with an angle of 64.5 ± 23.39° (35-110), which modified secondarily to measure 39.5 ± 6.15° (27-45) in the middle of the SCM muscle. At this level, the great auricular nerve and the external jugular vein were almost parallel (1.3° of average difference) and the distance that separated them was 2.24 ± 0.79 cm (0.8-3.5). CONCLUSION: Our study gave us a precise description of the superficial cervical plexus. All the measures allowed the establishment of the routes and the links of these structures to propose peroperating actions to prevent these facial sensory deficits.

Microsurgical anatomy of the fourth ventricle.

Anatomical description of the fourth ventricle is essential for an accurate understanding of its related tumoral pathologies and surgical approach respecting cerebellar and brainstem structures. Numerous cadaver pictures illustrate this chapter which contains V4 floor and roof description and its vascularization.

Evaluation of hydrogen peroxide and ozone residue levels on N95 masks following chemical decontamination.

BACKGROUND: Hydrogen peroxide and ozone have been used as chemical decontamination agents for N95 masks during supply shortages. If left behind on the masks, the residues of both chemicals represent a potential health hazard by skin contact and respiratory exposure. AIM: Characterization of hydrogen peroxide and ozone residues on mask surfaces after chemical decontamination. METHODS: Various N95 masks were decontaminated using two commercial systems employing either aerosol spray or vaporization of hydrogen peroxide in the presence of ozone. Following the decontamination, the masks were aired out to eliminate moisture and potential chemical residues. The residual hydrogen peroxide and ozone were monitored in the gas phase above the mask surface, and hydrogen peroxide residue directly on mask surfaces using a colorimetric assay. FINDINGS: After decontamination, hydrogen peroxide and ozone were detectable in the gas phase in the vicinity of masks even after 5 h of aeration. Hydrogen peroxide was also detected on all studied masks, and levels up to 56 mg per mask were observed after 0.5 h of aeration. All residues gradually decreased with aeration, likely due to decomposition and vaporization. CONCLUSION: Hydrogen peroxide and ozone were present on N95 masks after decontamination. With appropriate aeration, the gaseous residue levels in the vicinity of the masks decreased to permissible levels as defined by the US Occupational Safety and Health Administration. Reliable assays to monitor these residues are necessary to ensure the safety of the mask users.

[Livedoid erythema of the lower back revealing thrombosed abdominal aortic aneurysm]. / Érythème lombaire livédoïde révélateur d'un anévrisme thrombosé de l'aorte abdominale.

BACKGROUND: We report the case of a patient presenting a very painful livedo of the lower back as well as paraparesis revealing a complicated abdominal aortic aneurysm. PATIENTS AND METHODS: A 61-year-old man was referred to our emergency unit for sudden lower back pain and weakness of the lower limbs. He had a large and very painful livedo racemosa on the lower back as well as partial neurological deficit of the lower limbs. Abdominal CAT revealed a bulky thrombosed infrarenal aortic aneurysm. Despite surgery, ischaemia worsened, leading to cutaneous then muscular and visceral necrosis, followed by death. DISCUSSION: Livedo racemosa of the lower limbs may be the consequence of thrombosis or embolism resulting from an abdominal aortic aneurysm. Livedo racemosa on other skin areas is uncommon but may be due to the same physiopathology. Neurological deficit is occasionally associated with a complicated abdominal aortic aneurysm or with surgical treatment thereof. However, to our knowledge, livedo on the back associated with neurological deficit has not yet been reported. Such an association should prompt practitioners to screen for a thrombosed aortic aneurysm. Furthermore, this condition is also likely to carry a poor prognosis because of the proximal secondary location of the thrombotic phenomenon, involving the lumbar arteries, which supply the medullar, cutaneous and muscular arteries.

Fibroblast growth factor 2 internal ribosome entry site (IRES) activity ex vivo and in transgenic mice reveals a stringent tissue-specific regulation.

Fibroblast growth factor 2 (FGF-2) is a powerful mitogen involved in proliferation, differentiation, and survival of various cells including neurons. FGF-2 expression is translationally regulated; in particular, the FGF-2 mRNA contains an internal ribosome entry site (IRES) allowing cap-independent translation. Here, we have analyzed FGF-2 IRES tissue specificity ex vivo and in vivo by using a dual luciferase bicistronic vector. This IRES was active in most transiently transfected human and nonhuman cell types, with a higher activity in p53 -/- osteosarcoma and neuroblastoma cell lines. Transgenic mice were generated using bicistronic transgenes with FGF-2 IRES or encephalomyocarditis virus (EMCV) IRES. Measurements of luciferase activity revealed high FGF-2 IRES activity in 11-d-old embryos (E11) but not in the placenta; activity was high in the heart and brain of E16. FGF-2 IRES activity was low in most organs of the adult, but exceptionally high in the brain. Such spatiotemporal variations were not observed with the EMCV IRES. These data, demonstrating the strong tissue specificity of a mammalian IRES in vivo, suggest a pivotal role of translational IRES- dependent activation of FGF-2 expression during embryogenesis and in adult brain. FGF-2 IRES could constitute, thus, a powerful tool for gene transfer in the central nervous system.

[Morphological anatomy of the cranial nerves in their cisternal segment (III-XII)]. / Anatomie morphologique des nerfs crâniens dans leur portion cisternale (du III au XII).

One hundred brains (first injected in cerebral arteries and veins with latex neoprene or India ink and studied under optic magnification) illustrate this anatomic chapter concerning the microsurgical anatomy of the cisternal segment, the neurovascular relationships, and the blood supply of the IIIrd to the XIIth cranial nerves.

Surgical anatomy of the jugular foramen.

The jugular foramen (JF) is a canal that makes communication between the posterior cranial fossa and the upper neck for one third of the cranial nerves and for the main venous channel of the brain. From a lateral view, the JF is protected by multiple layers of muscles and by the outer surface of the petrous bone. Surgical exposure of the JF is usually justified by the removal of benign tumors that grow in this region. In the first part of the present study we describe the surgical anatomy of the JF Then, we detail the relevant points of a stepwise surgical progression of three lateral skull base approaches with a gradual level of exposure and invasiveness. The infralabyrinthine transsigmoid transjugular-high cervical approach is a conservative procedure that associates a retrolabyrinthine approach to a lateral dissection of the upper neck, exposing the sinojugular axis without mobilization of the facial nerve. In the second step, the external auditory canal is transsected and the intrapetrous facial nerve is mobilized, giving more exposure of the carotid canal and middle ear cavity. In the third step, a total petrosectomy is achieved with sacrifice of the cochlea, giving access to the petrous apex and to the whole course of the intrapetrous carotid artery. Using the same dissection of the soft tissues from a lateral trajectory, these three approaches bring solutions to the radical removal of distinct tumor extensions. While the first step preserves the facial nerve and intrapetrous neurootologic structures, the third one offers a wide but more aggressive exposure of the JF and related structures.

Microvascular decompression for hemifacial spasm: Outcome on spasm and complications. A review.

Over the last decades microvascular decompression (MVD) has been established as the curative treatment of the primary Hemifacial Spasm (HFS), proven to be linked in almost all cases to a neurovascular compression of the facial nerve. Because the disease is not life-threatening and MVD not totally innocuous, efficacy and safety have to be weighted before decision taken of indicating surgery. The authors have been charged by the French Speaking Society of Neurosurgery to conduct a detailed evaluation of the probability of relief of the spasm that MVD is able to obtain, together with its potential complications. For the review, the authors have gone through the reports available from the Pubmed system. Eighty-two publications have been read and analysed, totalizing more than 10,000 operated cases. In most series, the percentage of patients with total relief ranged between 85% and 90%. Relief was obtained after a certain delay in as many as in 33%±8% of the patients in many series. For those, delay lasted around one year in 12% of them. When effect of MVD was considered achieved, relief remained permanent in all but 1%-2% of the long-term followed patients. As regards to complications, risk of permanent cranial nerve deficit was evaluated at 1%-2% for facial palsy, 2%-3% for non-functional hearing loss, 0.5%-1% for lower cranial nerve dysfunction. Risk of stroke was at 0.1% and mortality at 0.1%. CSF leakage and related complications could be reduced at less than 2% in most series provided careful closing techniques be applied. Complications were at a higher rate in repeated MVD. MVD is an effective curative method for almost all the patients affected with primary HFS. Because MVD for HFS is functional surgery, scrupulous consideration of its potential risks, together with the ways to avoid complications are of paramount importance. When MVD is estimated to have failed, it is wise to wait one year before considering to repeat surgery, as number of patients may benefit from delayed effect. This is the more so as important as repeated surgery entails a higher rate of complications.

Surgical anatomy for hemifacial spasm.

Classically in the cerebello-pontine angle the facial (CN VII) and vestibular-cochlear (CN VIII) nerves should run parallel with the anterior inferior cerebellar artery, whereas the lower nerves (CN IX-XI) continue with the posterior-inferior-cerebellar artery (PICA). In fact, this is not always true, particularly when dealing with hemispasm surgery where the relationships between CN VII, CN VIII and PICA are often different and closer. Knowledge of anatomical bases in surgical situation will help neurosurgeons to appreciate anatomical nuances, that are important to increase effectiveness and safety of hemifacial spasm surgery.

Microvascular decompression for hemifacial spasm : Surgical techniques and intraoperative monitoring.

Primary hemifacial spasm with few exceptions is due to the vascular compression of the facial nerve that can be evidenced with high resolution MRI. Microvascular decompression is the only curative treatment for this pathology. According to literature review detailed in chapter "conflicting vessels", the compression is located at the facial Root Exit Zone (REZ) in 95% of the cases, and in 5% distally at the cisternal or the intrameatal portion of the root as the sole conflict or in addition to one at brainstem/REZ. Therefore, exploration has to be performed on the entire root, from the ponto-medullary fissure to the internal auditory meatus. Because microvascular decompression is functional surgery, the procedure should be as harmless as possible and with a high probability of permanent efficacy. Besides facial palsy, main complications are hearing loss, tinnitus and gait disturbances. Causes are cochlea/labyrinth ischemia due to manipulations of their nutrient arteries and/or stretching of the eight nerve complex. To minimize the latter, the approach should not be with lateral-to-medial retraction of the cerebellar hemisphere, but along an infra-floccular trajectory, from below. In fact, most of the neurovascular conflicts are situated ventro-caudally to facial REZ at the brainstem, particularly those from a megadolicho-vertebrobasilar artery and its posterior inferior-cerebellar branch. Also, care should be taken not to cause any injury of the manipulated vessels or stretching of their perforators to brainstem. Heating from bipolar coagulation must be avoided. The inserted material used to maintain the offending vessel(s) away must not be neo-compressive. Intraoperative neuromonitoring is considered to be useful for achieving safe surgery at least until the learning curve has reached an optimal level, particularly BrainstemAuditory Evoked Potentials recordings. Increase in latency and/or decrease in amplitude of wave V warn excessive stretching or damage to the cochlear nerve, and decrease in amplitude of wave I signals possible ischemia of the cochlea. Free-running EMG of the facial muscles may warn against excessive manipulation of the facial nerve. Recording of the lateral spread responses - which are a sign of hyperexcitabilty of the facial motor system - may provide information on completeness of the decompression.

Introduction to primary hemifacial spasm: A neurosurgical disease.

Primary hemifacial spasm is a hyperactive cranial nerve syndrome. The cause is always a neurovascular compression, generally at the root exit zone from the brainstem. Its curative treatment is microvascular decompression, that may be performed as a first option, or secondarily when botulinum toxin injections fail.

Hemifacial spasm associated with other cranial nerve syndromes: Literature review.

Hyperactive dysfunction may affect all cranial nerves in the posterior fossa. According to literature review and personal experience, hemifacial spasm was found to be associated not only with the most frequent cranial nerve syndromes, namely: trigeminal neuralgia, vago-glossopharyngeal neuralgia or VIIIth nerve disturbances manifested by vertigo, tinnitus, hearing decrease, but also with rarer syndromes like geniculate neuralgia, masticatory spasm etc. Also, a number of publications have pointed out the relatively high incidence of the coexistence of hemifacial spasm and systemic blood hypertension; both can be cured by vascular decompression of the ventrolateral aspect of the medulla and IX-Xth route entry zone (REZ) together with the facial REZ. Even more complex clinical presentations have been encountered, corresponding to disturbances in several cranial nerve nuclei. Some could be attributed to neurovascular conflicts from elongated arteries invaginated into the brainstem, and cured by microvascular decompression surgery. When confronted with such complex, and therefore misleading, syndrome, it is advised to search for vascular conflicts at the brainstem using high-resolution MRI exploration.

The conflicting vessels in hemifacial spasm: Literature review and anatomical-surgical implications.

Since several decades, it has been established that so-called primary hemifacial spasm is linked to neuro-vascular conflicts in the facial nerve, especially its root exit zone (REZ). Based on our review of the detailed publications of literature (2489 patients), together with our own series (340 patients), the responsible vessels found at surgery were: the posterior inferior cerebellar artery in 47.2%, the anterior inferior cerebellar artery in 45.9%, the vertebro-basilar artery in 17.5%, another (smaller) artery in 11.7%. Participation of veins was very diversely estimated according to series: 4.9% on average. Multiple neuro-vascular conflicts in a same individual were frequently observed, in the order of 20 to 30% according to authors, 37% in our series. Also, abnormal conformation of the posterior fossa may play a role, such as flatness of the posterior fossa or exiguity of the cerebello-pontine angle cistern. Whatever, most neurovascular conflicts are located at brainstem and/or ventrocaudally to the facial REZ, in the order of 95% of the patients. The anatomical location and conformation of the compressive vessel(s) are crucial in determining the difficulties to identify the responsible conflict(s) and to perform effective and safe decompression. Main difficulties are encountered in cases with arteriosclerotic megadolicho-vertebrobasilar artery, at brainstem, especially when PICA and/or AICA come in association, or for neurovascular conflict(s) located at the cisternal or the intrameatal portions of the facial root. Later ones can be alone or in addition to NVC at brainstem/REZ.

PDV-based estimation of ejecta particles' mass-velocity function from shock-loaded tin experiment.

A metallic tin plate with a given surface finish of wavelength λ ≃ 60 µm and amplitude h ≃ 8 µm is explosively driven by an electro-detonator with a shock-induced breakout pressure PSB = 28 GPa (unsupported). The resulting dynamic fragmentation process, the so-called "micro-jetting," is the creation of high-speed jets of matter moving faster than the bulk metallic surface. Hydrodynamic instabilities result in the fragmentation of these jets into micron-sized metallic particles constituting a self-expanding cloud of droplets, whose areal mass, velocity, and particle size distributions are unknown. Lithium-niobate-piezoelectric sensor measured areal mass and Photonic Doppler Velocimetry (PDV) was used to get a time-velocity spectrogram of the cloud. In this article, we present both experimental mass and velocity results and we relate the integrated areal mass of the cloud to the PDV power spectral density with the assumption of a power law particle size distribution. Two models of PDV spectrograms are described. The first one accounts for the speckle statistics of the spectrum and the second one describes an average spectrum for which speckle fluctuations are removed. Finally, the second model is used for a maximum likelihood estimation of the cloud's parameters from PDV data. The estimated integrated areal mass from PDV data is found to agree well with piezoelectric results. We highlight the relevance of analyzing PDV data and correlating different diagnostics to retrieve the physical properties of ejecta particles.