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Some bullets, called tracer and API bullets, contain a pyrotechnical charge. The charge in the bottom of a tracer bullet burns in flight and enables the shooter or an observer to see the bullet’s trajectory. An Armor Piercing Incendiary (API) bullet contains a hard core and a pyrotechnical charge that ignites on impact with a hard target. These bullets are designed to both pierce armor and ignite combustible materials. Both tracer and API bullets are quintessentially military ammunition, but some 7.62x39mm caliber variants are occasionally used in crimes. This fact triggered a study on the behavior of these bullets in soft tissue. Two different types of tracer bullets and two different types of API bullets were tested. The tracer bullets behaved similarly in a soft tissue simulant, in terms of energy transfer and deflection. These bullets deflected more from their original trajectory than the tested API bullets and the full metal jacket (FMJ) bullets that were tested as a reference. The two types of API bullets behaved completely different in the soft tissue simulant, especially in terms of energy transfer. One type yawed very late in the simulant and stayed intact, transferring little kinetic energy. The other type yawed early and disintegrated in the simulant, transferring much more of its kinetic energy, causing massive tissue (simulant) disruption. The difference in bullet behaviour was caused by a small but important difference in bullet design with the two types of API bullets. •7.62x39mm tracer bullets change course very strongly in soft tissue.•7.62x39mm API bullets can yaw very late in soft tissue, depending on their design.•7.62x39mm API bullets can disintegrate in soft tissue, depending on their design.

The notochord is a major regulator of embryonic patterning in vertebrates and abnormal notochordal development is associated with a variety of birth defects in man. Proper knowledge of the development of the human notochord, therefore, is important to understand the pathogenesis of these birth defects. Textbook descriptions vary significantly and seem to be derived from both human and animal data whereas the lack of references hampers verification of the presented data. Therefore, a verifiable and comprehensive description of the development of the human notochord is needed. Our analysis and three-dimensional (3D) reconstructions of 27 sectioned human embryos ranging from Carnegie Stage 8 to 15 (17-41 days of development), resulted in a comprehensive and verifiable new model of notochordal development. Subsequent to gastrulation, a transient group of cells briefly persists as the notochordal process which is incorporated into the endodermal roof of the gut while its dorsal side attaches to the developing neural tube. Then, the notochordal process embeds entirely into the endoderm, forming the epithelial notochordal plate, which remains intimately associated with the neural tube. Subsequently, the notochordal cells detach from the endoderm to form the definitive notochord, allowing the paired dorsal aortae to fuse between the notochord and the gut. We show that the formation of the notochordal process and plate proceeds in cranio-caudal direction. Moreover, in contrast to descriptions in the modern textbooks, we report that the formation of the definitive notochord in humans starts in the middle of the embryo, and proceeds in both cranial and caudal directions.

Determining the time since death, i.e., post-mortem interval (PMI), often plays a key role in forensic investigations. The current standard PMI-estimation method empirically correlates rectal temperatures and PMIs, frequently necessitating subjective correction factors. To overcome this, we previously developed a thermodynamic finite-difference (TFD) algorithm, providing a rigorous method to simulate post-mortem temperatures of bodies assuming a straight posture. However, in forensic practice, bodies are often found in non-straight postures, potentially limiting applicability of this algorithm in these cases. Here, we develop an individualised approach, enabling PMI reconstruction for bodies in arbitrary postures, by combining photogrammetry and TFD modelling. Utilising thermal photogrammetry, this approach also represents the first non-contact method for PMI reconstruction. The performed lab and crime scene validations reveal PMI reconstruction accuracies of 0.26 h ± 1.38 h for true PMIs between 2 h and 35 h and total procedural durations of ~15 min. Together, these findings broaden the potential applicability of TFD-based PMI reconstruction. Establishing the time since death (TSD) is vital in many forensic investigations. By combining thermometry, photogrammetry and numerical thermodynamic modelling, the TSD can be determined non-invasively for bodies of arbitrary shape and posture with an unprecedented accuracy of 0.26 h ± 1.38 h.

The detailed morphology of human development has intrigued scientists and the medical field alike. However, the scarcity of specimens hampers detailed mapping of tissue architecture. Furthermore, inaccuracies in the description of human development have crept into textbooks from observations of animal models that are extrapolated to humans. By mapping normal developmental processes and patterns, such as the growth and relative placement of organs, congenital anomalies can be better understood. de Bakker et al. generated interactive three-dimensional digital reconstructions based on the Carnegie collection of histologically sectioned human embryos spanning the first 2 months of gestation. These interactive models will serve as educational and scientific resources for normal and abnormal human development. Science , this issue p. 10.1126/science.aag0053 Interactive three-dimensional models unveil early human development. Current knowledge about human development is based on the description of a limited number of embryonic specimens published in original articles and textbooks, often more than 100 years ago. It is exceedingly difficult to verify this knowledge, given the restricted availability of human embryos. We created a three-dimensional digital atlas and database spanning the first 2 months of human development, based on analysis of nearly 15,000 histological sections of the renowned Carnegie Collection of human embryonic specimens. We identified and labeled up to 150 organs and structures per specimen and made three-dimensional models to quantify growth, establish changes in the position of organs, and clarify current ambiguities. The atlas provides an educational and reference resource for studies on early human development, growth, and congenital malformations.

Estimation of the postmortem interval in advanced postmortem stages is a challenging task. Although there are several approaches available for addressing postmortem changes of a (human) body or its environment (ecologically and/or biochemically), most are restricted to specific timeframes and/or individual and environmental conditions. It is well known, for instance, that buried bodies decompose in a remarkably different manner than on the ground surface. However, data on how established methods for PMI estimation perform under these conditions are scarce. It is important to understand whether and how postmortem changes are affected under burial conditions, if corrective factors could be conceived, or if methods have to be excluded for respective cases. We present the first multi-methodological assessment of human postmortem decomposition carried out on buried body donors in Europe, at the Amsterdam Research Initiative for Sub-surface Taphonomy and Anthropology (ARISTA) in the Netherlands. We used a multidisciplinary approach to investigate postmortem changes of morphology, skeletal muscle protein decomposition, presence of insects and other necrophilous animals as well as microbial communities (i.e., microbiomes) from August to November 2018 associated with two complete body exhumations and eight partial exhumations. Our results clearly display the current possibilities and limitations of methods for PMI estimation in buried remains and provide a baseline for future research and application.

Over the last few years, fetal postmortem microfocus computed tomography (micro-CT) imaging has increased in popularity for both diagnostic and research purposes. Micro-CT imaging could be a substitute for autopsy, particularly in very early gestation fetuses for whom autopsy can be technically challenging and is often unaccepted by parents. This article provides an overview of the latest research in fetal postmortem micro-CT imaging with a focus on diagnostic accuracy, endovascular staining approaches, placental studies and the reversibility of staining. It also discusses new methods that could prove helpful for micro-CT of larger fetuses. While more research is needed, contrast-enhanced micro-CT has the potential to become a suitable alternative to fetal autopsy. Further research using this novel imaging tool could yield wider applications, such as its practise in imaging rare museum specimens.

At this moment, no method is available to objectively estimate the temperature to which skeletal remains have been exposed during a fire. Estimating this temperature can provide crucial information in a legal investigation. Exposure of bone to heat results in observable and measurable changes, including a change in colour. To determine the exposure temperature of experimental bone samples, heat related changes in colour were systemically studied by means of image analysis. In total 1138 samples of fresh human long bone diaphysis and epiphysis, varying in size, were subjected to heat ranging from room temperature to 900 °C for various durations and in different media. The samples were scanned with a calibrated flatbed scanner and photographed with a Digital Single Lens Reflex camera. Red, Green, Blue values and Lightness, A-, and B-coordinates were collected for statistical analysis. Cluster analysis showed that discriminating thresholds for Lightness and B-coordinate could be defined and used to construct a model of decision rules. This model enables the user to differentiate between seven different temperature clusters with relatively high precision and accuracy. The proposed decision model provides an objective, robust and non-destructive method for estimating the exposure temperature of heated bone samples.

Whether the fascia iliaca compartment block (FICB) involves the obturator nerve (ON) remains controversial. Involvement may require that the injectate spreads deep in the cranial direction, and might thus depend on the site of injection. Therefore, the effect of suprainguinal needle insertion with five centimeters of hydrodissection-mediated needle advancement (S-FICB-H) on ON involvement and cranial injectate spread was studied in this radiological cadaveric study. Results were compared with suprainguinal FICB without additional hydrodissection-mediated needle advancement (S-FICB), infrainguinal FICB (I-FICB), and femoral nerve block (FNB). Seventeen human cadavers were randomized to receive ultrasound-guided nerve block with a 40 mL solution of local anesthetic and contrast medium, on both sides. Injectate spread was objectified using computed tomography. The femoral and lateral femoral cutaneous nerves were consistently covered when S-FICB-H, S-FICB or FNB was applied, while the ON was involved in only one of the 34 nerve blocks. I-FICB failed to provide the same consistency of nerve involvement as S-FICB-H, S-FICB or FNB. Injectate reached most cranial in specimens treated with S-FICB-H. Our results demonstrate that even the technique with the most extensive cranial spread (S-FICB-H) does not lead to ON involvement and as such, the ON seems unrelated to FICB. Separate ON block should be considered when clinically indicated.

•Virtual bones generated from ‘clinical’ CT scans are larger in size than the dry skeletal element.•Correctly locating landmarks on virtual bones differs per modality and landmark.•Methods derived from virtual bones may not always be applied to dry bones. Clinical radiology is increasingly used as a source of data to test or develop forensic anthropological methods, especially in countries where contemporary skeletal collections are not available. Naturally, this requires analysis of the error that is a result of low accuracy of the modality (i.e. accuracy of the segmentation) and the error that arises due to difficulties in landmark recognition in virtual models. The cumulative effect of these errors ultimately determines whether virtual and dry bone measurements can be used interchangeably. To test the interchangeability of virtual and dry bone measurements, 13 male and 14 female intact cadavers from the body donation program of the Amsterdam UMC were CT scanned using a standard patient scanning protocol and processed to obtain the dry os coxae. These were again CT scanned using the same scanning protocol. All CT scans were segmented to create 3D virtual bone models of the os coxae (‘dry’ CT models and ‘clinical’ CT models). An Artec Spider 3D optical scanner was used to produce gold standard ‘optical 3D models’ of ten dry os coxae. The deviation of the surfaces of the 3D virtual bone models compared to the gold standard was used to calculate the accuracy of the CT models, both for the overall os coxae and for selected landmarks. Landmark recognition was studied by comparing the TEM and %TEM of nine traditional inter-landmark distances (ILDs). The percentage difference for the various ILDs between modalities was used to gauge the practical implications of both errors combined. Results showed that ‘dry’ CT models were 0.36–0.45mm larger than the ‘optical 3D models’ (deviations −0.27mm to 2.86mm). ‘Clinical’ CT models were 0.64–0.88mm larger than the ‘optical 3D models’ (deviations −4.99mm to 5.00mm). The accuracies of the ROIs were variable and larger for ‘clinical’ CT models than for ‘dry’ CT models. TEM and %TEM were generally in the acceptable ranges for all ILDs whilst no single modality was obviously more or less reliable than the others. For almost all ILDs, the average percentage difference between modalities was substantially larger than the average percentage difference between observers in ‘dry bone’ measurements only. Our results show that the combined error of segmentation- and landmark recognition error can be substantial, which may preclude the usage of ‘clinical’ CT scans as an alternative source for forensic anthropological reference data.

IntroductionLow and high volume mid-thigh (ie, distal femoral triangle) and distal adductor canal block approaches are frequently applied for knee surgical procedures. Although these techniques aim to contain the injectate within the adductor canal, spillage into the popliteal fossa has been reported. While in theory this could improve analgesia, it might also result in motor blockade due to coverage of motor branches of the sciatic nerve. This radiological cadaveric study, therefore, investigated the incidence of coverage of sciatic nerve divisions after various adductor canal block techniques.MethodsEighteen fresh, unfrozen and unembalmed human cadavers were randomized to receive ultrasound-guided distal femoral triangle or distal adductor canal injections, with 2 mL or 30 mL injectate volume, on both sides (36 blocks in total). The injectate was a 1:10 dilution of contrast medium in local anesthetic. Injectate spread was assessed using whole-body CT with reconstructions in axial, sagittal and coronal planes.ResultsNo coverage of the sciatic nerve or its main divisions was found. The contrast mixture spread to the popliteal fossa in three of 36 nerve blocks. Contrast reached the saphenous nerve after all injections, whereas the femoral nerve was always spared.ConclusionsAdductor canal block techniques are unlikely, even when using larger volumes, to block the sciatic nerve, or its main branches. Furthermore, injectate reached the popliteal fossa in a small minority of cases, yet if a clinical analgesic effect is achieved by this mechanism is still unknown.