Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 98
Filtrar
1.
Leg Med (Tokyo) ; 55: 102013, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34999531

RESUMO

Tibetan ethnic group is one of the oldest ethnic groups in China and South Asia. This study set out to analyze the dental development and validate Demirjian method and Willems method in estimating dental age of Tibetan children and adolescents, and to modify Demirjian method based on Tibetan population to provide ethnic-specific reference data and a more reliable method for forensic age assessment in Tibetan ethnic group. In this study, 1951 samples aged between 4 and 15 years were retrospectively collected and analyzed. Multiple linear regression was used to establish relationship between chronological age (CA) and developmental stages of left mandibular permanent teeth. The accuracy of the modified method was tested and compared with that of Demirjian and Willems method. Results showed that dental maturity score (DMS) was significantly greater in girls than in boys in all age groups except for the 4-year age group (p < 0.05). Mean absolute error (MAE) was 0.96 years for both boys and girls by Demirjian method, and 1.06 and 1.16 years for boys and girls respectively by Willems method. Adjusted scores table was established and tested. The age of boys was overestimated by 0.13 years and the age of girls was underestimated by 0.06 years by the adjusted scores table. MAE was lower than that of the other two methods. In conclusion, Demirjian method and Willems method was not sufficiently accurate in estimating dental age of Tibetan population. The modified method was more suitable for dental age estimation of Tibetan population than Demirjian and Willems method.


Assuntos
Determinação da Idade pelos Dentes , Dente , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Radiografia Panorâmica , Estudos Retrospectivos , Tibet
2.
Int J Legal Med ; 135(6): 2409-2421, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34459973

RESUMO

Deep learning based on radiological methods has attracted considerable attention in forensic anthropology because of its superior classification capacities over human experts. However, radiological instruments are limited in their nature of high cost and immobility. Here, we integrated a deep learning algorithm and three-dimensional (3D) surface scanning technique into a portable system for pelvic sex estimation. Briefly, the images of the ventral pubis (VP), dorsal pubis (DP), and greater sciatic notch (GSN) were cropped from virtual pelvic samples reconstructed from CT scans of 1000 individuals; 80% of them were used to train and internally evaluate convolutional neural networks (CNNs) that were then evaluated externally with the remaining samples. An additional 105 real pelvises were documented virtually with a handheld 3D surface scanner, and the corresponding snapshots of the VP, DP, and GSN were predicted by the trained CNN models. The CNN models achieved excellent performance in the external testing using CT-based images, with accuracies of 98.0%, 98.5%, and 94.0% for VP, DP, and GSN, respectively. When the CT-based models were applied to 3D scanning images, they obtained satisfactory accuracies above 95% on the VP and DP images compared to the GSN with 73.3%. In a single-blind trial, a multiple design that combined the three CNN models yielded a superior accuracy of 97.1% with 3D surface scanning images over two anthropologists. Our study demonstrates the great potential of deep learning and 3D surface scanning for rapid and accurate sex estimation of skeletal remains.


Assuntos
Aprendizado Profundo , Imageamento Tridimensional/métodos , Redes Neurais de Computação , Determinação do Sexo pelo Esqueleto/métodos , Feminino , Humanos , Imageamento Tridimensional/instrumentação , Masculino , Pelve/diagnóstico por imagem , Osso Púbico/diagnóstico por imagem , Tomografia Computadorizada por Raios X
3.
Am J Forensic Med Pathol ; 42(3): 258-262, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34397510

RESUMO

ABSTRACT: Postmortem computed tomography (PMCT), PMCT angiography, and 3-dimensonal (3D) printing technology are increasingly applied to forensic practice. Although their effectiveness is undeniably confirmed, their potential role in practice still needs to be further explored. Here, we report a typical case in which such 4 technologies were applied to a woman found dead with stomach content beneath the head on the pillow in her residence. At first, the cause of death was simply considered as hypertensive cerebral hemorrhage after preliminary examination. However, the initial judgment was questioned by her family for her devoid of hypertension history. As indicated by the targeted PMCT with cerebral angiography, the woman died of pathological cerebral hemorrhage due to arteriovenous malformation, which was still unconvincing enough for the family because in violent death, some cerebral hemorrhage could also be located in the same position. Finally, the family came to be convinced when the close connection between the deformed blood vessels and hematoma was perfectly demonstrated by the application of 3D printing technology. This study proved that it can be an efficient tool for identifying the cause of death when the integration is made of 3D printing technology and PMCT angiography, as a more intuitive evidence of forensic science.


Assuntos
Malformações Arteriovenosas/diagnóstico por imagem , Hemorragia Cerebral/etiologia , Angiografia por Tomografia Computadorizada , Morte Súbita/etiologia , Impressão Tridimensional , Adulto , Angiografia Cerebral , Feminino , Humanos , Ruptura Espontânea/diagnóstico
4.
Forensic Sci Res ; 6(2): 152-158, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34377573

RESUMO

It may be difficult to distinguish the cause of death in drowning cases without specific findings. The aim of this study was to explore the forensic value of thoracic postmortem computed tomography (PMCT) using routine images and three-dimensional (3D) image reconstructions. The imaging data of PMCT examinations of six drowning cadavers, aged 21-54 years, were analyzed. Twelve victims of sudden death from coronary artery disease (CAD) were chosen as a control group. After 3D bilateral lung images were reconstructed using image processing software, an interactive medical image control system was used to measure and analyze parameters including lung volume, lung volume ratio, mean CT value of the whole lung, and lung CT value distribution curves. Lung volume and lung volume ratio were used to assess the shape changes of the lung. Lung CT value distribution curves showed the corresponding number of pixels of the different CT values in the lung image. Lung volume was not significantly larger in drowning cases (mean 2 958 cm3) than in controls (mean 2 342 cm3). Lung volume ratio values in the drowning group (mean 0.3156) were greater than those in the control group (mean 0.2763); (P = 0.02). There was no significant difference between the drowning and control group in the mean CT value of the whole lung. There were differences between lung CT value distribution curves in drowning victims and controls, with drowning victims showing a single peak and CAD cases showing a bimodal distribution. Thoracic PMCT is helpful for the forensic medical diagnosis of drowning. Lung volume ratio and lung CT value distribution are potential indicators to distinguish between drowning and CAD.

5.
Forensic Sci Res ; 6(1): 1-12, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-34007511

RESUMO

Forensic biomechanics gradually has become a significant component of forensic science. Forensic biomechanics is evidence-based science that applies biomechanical principles and methods to forensic practice, which has constituted one of the most potential research areas. In this review, we introduce how finite element techniques can be used to simulate forensic cases, how injury criteria and injury scales can be used to describe injury severity, and how tests of postmortem human subjects and dummy can be used to provide essential validation data. This review also describes research progress and new applications of forensic biomechanics in China.Key pointsThe review shows the main research progress and new applications of forensic biomechanics in China.The review introduces eight cases about the application of forensic biomechanics, including the multiple rigid body reconstruction, the finite element applications, study of mechanical properties, traffic crash reconstruction based on multiple techniques and analysis of morphomechanical mechanism about blood dispersal.Though forensic biomechanics has a great advantage for the evaluation of injury mechanisms, it still has some uncertainties owing to the uniqueness of the human anatomy, the complexity of biological materials, and the uncertainty of injury-causing circumstances.

6.
PLoS One ; 16(2): e0244390, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33556052

RESUMO

The aim of this study was to identify the influence of specimen geometry and size on the results of aortic uniaxial tensile tests using custom-designed tissue cutters, clamps and molds. Six descending thoracic aortas from pigs were used for rectangular sample tests, in which the circumferential and axial specimens had widths of 6 mm, 8 mm and 10 mm. The other six aortas were used for the dog-bone-shaped sample tests and were punched into circumferential, axial and oblique specimens with widths of 2 mm, 4 mm and 6 mm. We performed uniaxial tensile tests on the specimens and compared the test results. The results showed that mid-sample failure occurred in 85.2% of the dog-bone-shaped specimens and in 11.1% of the rectangular samples, which could be caused by Saint-Venant's principle. Therefore, rectangular specimens were not suitable for aortic uniaxial tensile testing performed until rupture. The results also showed that the size effect of the aorta conformed to Weibull theory, and dog-bone-shaped specimens with a width of 4 mm were the optimal choice for aortic uniaxial tensile testing performed until rupture.


Assuntos
Aorta , Estresse Mecânico , Resistência à Tração , Animais , Fenômenos Biomecânicos , Elasticidade , Suínos
7.
Int J Legal Med ; 135(3): 817-827, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33392655

RESUMO

Seasonal or monthly databases of the diatom populations in specific bodies of water are needed to infer the drowning site of a drowned body. However, existing diatom testing methods are laborious, time-consuming, and costly and usually require specific expertise. In this study, we developed an artificial intelligence (AI)-based system as a substitute for manual morphological examination capable of identifying and classifying diatoms at the species level. Within two days, the system collected information on diatom profiles in the Huangpu and Suzhou Rivers of Shanghai, China. In an animal experiment, the similarities of diatom profiles between lung tissues and water samples were evaluated through a modified Jensen-Shannon (JS) divergence measure for drowning site inference, reaching a prediction accuracy of 92.31%. Considering its high efficiency and simplicity, our proposed method is believed to be more applicable than existing methods for seasonal or monthly water monitoring of diatom populations from sections of interconnected rivers, which would help police narrow the investigation scope to confirm the identity of an immersed body.


Assuntos
Bases de Dados Factuais , Diatomáceas/classificação , Afogamento/diagnóstico , Patologia Legal/métodos , Redes Neurais de Computação , Animais , Inteligência Artificial , China , Diatomáceas/microbiologia , Afogamento/microbiologia , Pulmão/microbiologia , Modelos Animais , Ratos , Ratos Sprague-Dawley , Rios/microbiologia , Estações do Ano , Sensibilidade e Especificidade
8.
Int J Legal Med ; 135(3): 913-920, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33392657

RESUMO

Forensic scholars are paying more attention to postmortem computed tomography (PMCT) and PMCT angiography (PMCTA), which are gradually becoming effective and practical methods in forensic practice. However, few studies have focused on the application of PMCTA to cardiac ventricular puncture-especially of the right ventricle. In this article, we introduce a pulmonary PMCTA approach by right ventricle cardiac puncture and its potential value in fatalities from pulmonary thromboembolism (PTE). The procedure was performed on 11 males and 6 females. PMCT was performed first; then a biopsy core needle was used for percutaneous puncture of the right ventricle under CT guidance. About 400 mL of contrast media was injected at a rate of 50 mL/8 s, followed by CT scanning. Visualization of the pulmonary artery contrast filling was complete in 9 cadavers, and the pulmonary arteries showed significant filling defects in 8 subjects. Unlike in clinical practice, the phenomenon of postmortem coagulation sometimes occurs in the vascular lumina after death. Therefore, the results of these 8 cases can only suggest or be highly suspicious of death from PTE. Then autopsy and histopathological examination confirmed that 4 of the above 8 patients were diagnosed with PTE; the remaining 4 had postmortem clot including chicken fat clot in the pulmonary artery. Pulmonary PMCTA approach is a simple, convenient, and effective method for the visualization of the pulmonary artery, which can be used as an effective auxiliary tool to identify PTE in forensic practice. It will also provide technical support to further investigate PTE imaging characteristics.


Assuntos
Autopsia , Angiografia por Tomografia Computadorizada/métodos , Ventrículos do Coração , Artéria Pulmonar/diagnóstico por imagem , Embolia Pulmonar/diagnóstico , Punções/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , China , Feminino , Medicina Legal , Humanos , Masculino , Pessoa de Meia-Idade
9.
Am J Forensic Med Pathol ; 42(3): 252-257, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33346976

RESUMO

ABSTRACT: We report cause of death after cardiac surgery using isolated cardiopulmonary organ computed tomography angiography (CTA) and a conventional autopsy. A 56-year-old man underwent aortic valve replacement and coronary artery bypass graft surgery under extracorporeal circulation. Massive bleeding occurred suddenly, and the patient died 25 days later. An autopsy revealed fibrinous exudate in the mediastinum and tight attachment of the pericardium to the heart; there were also clots and inflammatory exudate in the chest cavity. Separating the organs in the chest cavity was difficult, especially in the surgical area. We extracted the heart and lungs together and performed cardiovascular CTA and image reconstruction. Results showed spillage of the contrast agent from the anterior wall of the ascending aorta, approximately 4.5 cm from the replaced aortic valve. A histological examination confirmed that the site of contrast agent spillage was the sutured area of the ascending aorta, which was infected, necrotic, and had ruptured. Using the CTA approach for isolated cardiopulmonary organ imaging can accurately display the location of an aortic rupture, which further guides organ inspection and tissue sampling, and avoids irreversible damage to key regions. In conclusion, the approach we describe can provide evidence for determining cause of death.


Assuntos
Aorta/diagnóstico por imagem , Aorta/lesões , Ruptura Aórtica/diagnóstico por imagem , Autopsia/métodos , Angiografia por Tomografia Computadorizada , Valva Aórtica/cirurgia , Meios de Contraste , Ponte de Artéria Coronária/efeitos adversos , Diatrizoato de Meglumina , Circulação Extracorpórea , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias
10.
Am J Forensic Med Pathol ; 42(2): 194-197, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33031123

RESUMO

ABSTRACT: Traumatic unilateral vertebral artery (VA) injury can cause focal thrombosis and may block the basilar artery which can further lead to ischemic stroke and massive cerebral infarction and subarachnoid hemorrhage and even rapid death. Here, we present an autopsy case with a traumatic extracranial VA dissection in a motor traffic accident, and the identification of cause of death underwent 2 autopsies. A 62-year-old male pedestrian collided with the right rearview mirror of a car and fell down to the ground. He complained pains in the head and neck. Head computed tomography (CT) showed a right linear temporal bone fracture and a small left temporal subdural hematoma. Neck CT and magnetic resonance imaging (MRI) examination showed left transverse process fracture of the sixth cervical vertebra (C6) and left extracranial VA injury. After 6 days of hospitalization, the left temporal subdural hematoma had been nearly absorbed, and the man was discharged home. On day 15 after the traffic accident, the man suffered sudden unconsciousness accompanied by frequent vomiting at home. The man was taken to hospital, and there were no obvious abnormal findings by head CT examination. However, the man soon fell into a coma state and died 2 days later. The first autopsy was performed 7 days after death and confirmed a left transverse process fracture of C6 and that the deceased died of cerebral infarction and secondary subarachnoid hemorrhage caused by blunt force in the motor traffic accident. In the civil lawsuit, the traffic accident wrecker put forward the objection whether the deceased had fatal diseases. The second autopsy (84 days after the death) findings verified the left extracranial VA injury. Histopathological examination further showed intimal dissection and thrombus formation of the left extracranial VA and secondary basal arterial thromboembolism. Massive infarction of the brainstem and cerebellum was disclosed. Therefore, the deceased died of delayed massive brainstem and cerebellum infarction because of left extracranial VA dissection in the motor traffic accident.


Assuntos
Acidentes de Trânsito , Infartos do Tronco Encefálico/etiologia , Infarto Cerebral/etiologia , Pedestres , Dissecação da Artéria Vertebral/patologia , Infartos do Tronco Encefálico/patologia , Infarto Cerebral/patologia , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/lesões , Evolução Fatal , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fraturas da Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Dissecação da Artéria Vertebral/etiologia
11.
Leg Med (Tokyo) ; 47: 101778, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32829289

RESUMO

Sex estimation is an important part of creating a biological profile, and ultimately assisting in creating a presumptive identification of unidentified skeletal remains. However, manual methods of anthropometric are time-consuming and prone to observer variability. The present study is an attempt to estimation of sex from automatic measurement of patella by multidetector computed tomography (MDCT) in a contemporary Chinese population. Four measurements for every patella, including maximum height (MAXH), maximum breadth (MAXB), maximum thickness (MAXT) and patellar volume (PV), were automatically provided by the software from CT image of 300 Chinese. The sample is composed of 156 males and 144 females with an average age of 41.44 and 45.68 years, respectively. The statistical analyses showed that all variables were sexually dimorphic. Receiver operating characteristic (ROC) analysis was performed to estimate sex from patella. The univariate analysis of each patellar parameter yielded a sex classification accuracy rate of 73.1% to 85.7%. The classification accuracy rates of sex estimation using the combination of the patellar parameters are 81.9% to 91.6%. This paper provides indications that the patella is important bone for sex estimation and it may be used as an alternative in forensic cases when the skull and pelvis are unavailable.


Assuntos
Antropologia Forense/métodos , Tomografia Computadorizada Multidetectores , Patela/anatomia & histologia , Patela/diagnóstico por imagem , Determinação do Sexo pelo Esqueleto/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Curva ROC , Sensibilidade e Especificidade , Adulto Jovem
12.
Leg Med (Tokyo) ; 45: 101697, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32305675

RESUMO

The finite element (FE) method can potentially help in reconstructing skull fracture biomechanisms, enabling differentiation of the injury patterns caused by traffic accidents. This study aims to (1) reconstruct a motorcycle driver-car accident case using the total human model for safety and FE simulations; and (2) analyze the biomechanisms of fatal ring fractures in the motorcyclist's skull base to determine if the fatal craniocerebral injuries were caused by a fall onto the highway after hitting a pedestrian or by the subsequent impact of a car. We simulated a series of loading scenarios of falls onto the road and impacts by a car, with and without a helmet being used. We reconstructed the injury processes and compared the biomechanics results to the skull tolerance limit. For the scenario of falling with a helmet, the Von-Mises stress around the foramen magnum indicated ring fractures with a slight fracture at the impact site, consistent with that detected in a traditional forensic pathology autopsy. Moreover, we found that a helmet can significantly protect the skull by controlling the increase in stress around the impact site. However, it has very little effect on the skull base, neck, or cervical spine. We determined that the characteristic ring fracture was most probably caused by the fall onto the highway. Thus, the subsequent car accident did not contribute to the motorcyclist's death. Our study demonstrates that the FE model and method can explore injury biomechanisms, assisting in the identification of injury patterns in forensic practices.

13.
Medicine (Baltimore) ; 99(11): e19182, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32176043

RESUMO

RATIONALE: Postmortem forensic imaging technologies provide a noninvasive/minimally invasive approach for imaging of internal organ structures of the human body to detect injuries, diseases, and other morphologic changes. Currently, postmortem forensic imaging methods have been widely used in determination of the cause of death. However, these methods do not allow histologic examinations. Endoscopic autopsy emerged in the 1990s. Thoracoscopy and laparoscopy are mainly used to examine organs and tissues in the thoracic and abdominal cavity. Target tissues are also sampled for histologic examination. By combining postmortem forensic imaging with endoscopic autopsy, comprehensive examination of the corpse, organs, and sampling for histologic examination can be carried out. PATIENT CONCERNS: A 34-year-old woman was witnessed jumping into the river, sinking after struggling in the water. The body was found 24 hours later and confirmed with no vital signs. No preexisting medical conditions were known. DIAGNOSIS, INTERVENTIONS, AND OUTCOMES: Postmortem computed tomography, target coronary postmortem computed tomography angiography, and endoscopic autopsy were performed before conventional autopsy. Laparoscopic examination was used to examine the abdominal organs. The diaphragm and pericardium were cut open from the abdominal cavity to allow access to the examination of lungs and heart. Tissue samples were collected from various organs for histologic examination, and a diatom test was carried out on lung samples. Postmortem computed tomography revealed fluid in the paranasal sinuses, airways, stomach, and duodenum; emphysema aquosum; and mosaic pattern of the lung parenchyma. Endoscopic examination additionally detected Paltauf spots. The results were consistent with those of conventional autopsy. Histologic examination revealed pulmonary congestion, pulmonary edema, pulmonary emphysema, pulmonary hemorrhage, and congestion in multiple organs such as the liver, spleen, and kidneys. Diatoms were detected in lung tissues, which were identical in morphology to diatoms in water samples collected from the scene. The cause of death was determined as drowning. CONCLUSION: Combining forensic imaging and endoscopic autopsy for postmortem examination yields a more comprehensive and scientific finding, and the combination is minimally invasive and more acceptable to the family members. This method can be used as an alternative for conventional autopsy under specific circumstances.


Assuntos
Autopsia/métodos , Afogamento/diagnóstico , Adulto , Angiografia por Tomografia Computadorizada , Afogamento/diagnóstico por imagem , Afogamento/patologia , Endoscopia/métodos , Feminino , Patologia Legal/métodos , Humanos , Tomografia Computadorizada por Raios X
14.
J Biophotonics ; 13(4): e201960144, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31957147

RESUMO

This study investigated whether infrared spectroscopy combined with a deep learning algorithm could be a useful tool for determining causes of death by analyzing pulmonary edema fluid from forensic autopsies. A newly designed convolutional neural network-based deep learning framework, named DeepIR and eight popular machine learning algorithms, were used to construct classifiers. The prediction performances of these classifiers demonstrated that DeepIR outperformed the machine learning algorithms in establishing classifiers to determine the causes of death. Moreover, DeepIR was generally less dependent on preprocessing procedures than were the machine learning algorithms; it provided the validation accuracy with a narrow range from 0.9661 to 0.9856 and the test accuracy ranging from 0.8774 to 0.9167 on the raw pulmonary edema fluid spectral dataset and the nine preprocessing protocol-based datasets in our study. In conclusion, this study demonstrates that the deep learning-equipped Fourier transform infrared spectroscopy technique has the potential to be an effective aid for determining causes of death.


Assuntos
Aprendizado Profundo , Edema Pulmonar , Algoritmos , Autopsia , Causas de Morte , Humanos
15.
Int J Legal Med ; 134(3): 873-884, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31788707

RESUMO

Formalin-fixed paraffin-embedded (FFPE) tissues are commonly used both clinically and in forensic pathology. Recently, noncoding RNA (ncRNA) has attracted interest among molecular medical researchers. However, it remains unclear whether newly identified ncRNAs, such as long noncoding RNA (lncRNA) and circular RNA (circRNA), remain stable for downstream molecular analysis in FFPE tissues. Here, we assessed the feasibility of using autoptic FFPE brain tissues from eight individuals to perform quantitative molecular analyses. Selected RNA targets (9 mRNAs and 15 ncRNAs) with different amplicon lengths were studied by RT-qPCR in paired fresh and FFPE specimens. For RNA quality assessment, RNA purity and yield were comparable between the two sample cohorts; however, the RNA integrity number decreased significantly during FFPE sampling. Amplification efficiency also displayed certain variability related with amplicon length and RNA species. We found molecular evidence that short amplicons of mRNA, lncRNA, and circRNA were amplified more efficiently than long amplicons. With the assistance of RefFinder, 5S, SNORD48, miR-103a, and miR-125b were selected as reference genes given their high stability. After normalization, we found that short amplicon markers (e.g., ACTB mRNA and MALAT1 lncRNA) exhibited high consistency of quantification in paired fresh/FFPE samples. In particular, circRNAs (XPO1, HIPK3, and TMEM56) presented relatively consistent and stable expression profiles in FFPE tissues compared with their corresponding linear transcripts. Additionally, we evaluated the influence of prolonged storage time on the amplification of gene transcripts and found that short amplicons still work effectively in archived FFPE biospecimens. In conclusion, our findings demonstrate the possibility of performing accurate quantitative analysis of ncRNAs using short amplicons and standardized RT-qPCR assays in autopsy-derived FFPE samples.


Assuntos
Encéfalo/ultraestrutura , Lobo Frontal/química , Perfilação da Expressão Gênica , RNA Circular/análise , RNA Mensageiro/análise , RNA não Traduzido/análise , Patologia Legal/métodos , Formaldeído , Humanos , Técnicas de Amplificação de Ácido Nucleico , Inclusão em Parafina , Estabilidade de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fixação de Tecidos
16.
J Forensic Sci ; 65(3): 846-854, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31868923

RESUMO

The goal of this study was to investigate whether pulmonary edema could become a specific diagnostic marker for fatal hypothermia using Fourier transform infrared (FTIR) spectroscopy in combination with chemometrics. The spectral profile analysis indicated that hypothermia fatalities associated with pulmonary edema fluid contained more ß-sheet protein conformational structures than the control causes of death, which included sudden cardiac death, brain injury, cerebrovascular disease, mechanical asphyxiation, intoxication, and drowning. Subsequently, the results of principal component analysis (PCA) further revealed that the content of ß-sheet protein conformational structures in the pulmonary edema fluid was the main discriminatory marker between fatal hypothermia and the other causes of death. Ultimately, a robust postmortem diagnostic model for fatal hypothermia using a partial least-squares discriminant analysis (PLS-DA) algorithm was constructed. Pulmonary edema fluid spectra collected from eight new forensic autopsy cases that did not participate in the construction of the diagnostic model were predicted using the model. The results showed the causes of death of all these eight cases were correctly classified. In conclusion, this preliminary study demonstrates that FTIR spectroscopy in combination with chemometrics could be a promising approach for the postmortem diagnosis of fatal hypothermia.


Assuntos
Hipotermia/diagnóstico , Edema Pulmonar/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Algoritmos , Técnicas de Química Analítica , Análise Discriminante , Formaldeído , Humanos , Análise dos Mínimos Quadrados , Pulmão/patologia , Inclusão em Parafina , Análise de Componente Principal , Conformação Proteica em Folha beta
17.
Leg Med (Tokyo) ; 41: 101625, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31610412

RESUMO

The present study is an attempt to estimation of stature and sex from skull measurements by multidetector computed tomography (MDCT) in contemporary Chinese. In the present study, fifteen measurements for every skull were taken from CT image of 382 Chinese. The sample was composed of 200 males and 182 females with an average age of 47 and 46 years, respectively. Discriminant function was used in sex determination and regression analysis was used in stature estimation from skull measurements. The stepwise analysis of all measurements yielded a sex classification accuracy rate of 89.3%. The classification accuracy rates of the univariate discriminant function analyses were from 50.5% to 84.8%. For stature estimation, the standard error of estimate (SEE) ranged from 5.072 to 6.355 cm for male, from 5.090 to 5.829 cm for female, respectively. This study is the first to provide a metric and statistical characterization of the skull in contemporary Chinese, and indicates that it is feasible to sex estimation by skull measurement. Furthermore, the equations presented for stature estimation in this study may be used as alternatives in forensic cases, particularly in cases where better predictors such as the long bones are not available.


Assuntos
Estatura , Tomografia Computadorizada Multidetectores , Determinação do Sexo pelo Esqueleto/métodos , Crânio/diagnóstico por imagem , Pontos de Referência Anatômicos , Cefalometria , China , Análise Discriminante , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade
18.
Forensic Sci Int ; 303: 109943, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31546165

RESUMO

Crime scene reconstruction plays a significant role in crime solving by helping to determine the course of events. Non-invasive, high-resolution measurement and increased insight are always the goal of forensic crime scene documentation. However, entire crime scenes cannot be effectively reconstructed with traditional methods. In this study, we present a portable system that consists of a laser scanner, two hand-held structured light scanners and a low-cost virtual reality (VR) headset with a mobile power supply to conduct multi-angle and omnidirectional three-dimensional spatial data collection of crime scenes. To demonstrate practical use, a real case has been analysed to verify the feasibility and effectiveness of the system. The system accurately obtains information on decedent injuries, possible injury-inflicting tools and on-site traces. Various types of evidence from the crime scene can be jointly studied by three-dimensional visualization to develop a cohesive story. The data are presented via immersive VR rather than displayed on computer screens. The relationship between evidence chains enables us to achieve a complete crime scene reconstruction, using the specialized knowledge of experts and computer-aided forensic tools to analyse the causes of damage and identify suspects. The use of three- dimensional imaging techniques allows a more insightful survey and several useful analyses, such as accurate measurement, relative blood source location determination and injury-inflicting tool comparison.


Assuntos
Ciências Forenses/métodos , Homicídio , Realidade Virtual , Adulto , Manchas de Sangue , Estudos de Viabilidade , Feminino , Pé/anatomia & histologia , Traumatismos Cranianos Penetrantes/patologia , Humanos , Ferimentos Perfurantes/patologia
19.
Forensic Sci Int ; 302: 109922, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31442682

RESUMO

Diatom examinations have been widely used to perform drowning diagnosis in forensic practice. However, current methods for recognizing diatoms, which use light or electron microscopy, are time-consuming and laborious and often result in false positive or negative decisions. In this study, we demonstrated an artificial intelligence (AI)-based system to automatically identify diatoms in conjunction with a classical chemical digestion approach. By employing transfer learning and data augmentation methods, we trained convolutional neural network (CNN) models on thousands or tens of thousands of tiles from digital whole-slide images of diatom smears. The results showed that the trained model identified the regions containing diatoms in the tiles. In an independent test, where the slide samples were collected in forensic casework, the best CNN model demonstrated a performance competitive with those of 5 forensic pathologists with experience in diatom quantification. This pilot study paves the way for future intelligent diatom examinations; many efficient diatom extraction methods could be incorporated into our automated system.


Assuntos
Algoritmos , Diatomáceas , Afogamento/diagnóstico , Pulmão/patologia , Redes Neurais de Computação , Aprendizado Profundo , Patologia Legal/métodos , Humanos , Sensibilidade e Especificidade
20.
Forensic Sci Med Pathol ; 15(3): 332-341, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31054024

RESUMO

Postmortem diagnosis of extreme-weather-related deaths is a challenging forensic task. Here, we present a state-of-the-art study that employed attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy in combination with Chemometrics for postmortem diagnosis of fatal hypothermia/hyperthermia by biochemical investigation of plasma in rats. The results of principal component analysis (PCA) and spectral analysis revealed that plasma samples from the fatal hypothermia, fatal hyperthermia, and control groups, are substantially different from each other based on the spectral variations associated with the lipid, carbohydrate and nucleic acid components. Two partial least squares-discriminant analysis (PLS-DA) classification models (hypothermia-nonhypothermia and hyperthermia-nonhyperthermia binary models) with a 100% accuracy rate were constructed. Subsequently, internal cross-validation was performed to assess the robustness of these two models, which resulted in 98.1 and 100% accuracy. Ultimately, classification predictions of 42 unknown plasma samples were performed by these two models, and both models achieved 100% accuracy. Additionally, our results demonstrated that hemolysis and postmortem hypothermic/hyperthermic effects did not weaken the prediction ability of these two classification models. In summary, this work demonstrates ATR-FTIR spectroscopy's great potential for postmortem diagnosis of fatal hypothermia/hyperthermia.


Assuntos
Febre/diagnóstico , Hipotermia/diagnóstico , Plasma/química , Espectroscopia de Infravermelho com Transformada de Fourier , Animais , Biomarcadores/sangue , Glicemia/análise , Proteínas Sanguíneas/análise , Carboidratos/sangue , Análise Discriminante , Ácidos Graxos/sangue , Febre/sangue , Patologia Legal/métodos , Hipotermia/sangue , Lipídeos/sangue , Ácidos Nucleicos/sangue , Análise de Componente Principal , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...