Blood stains on the fabric often appear at the scene of the crime. The age determination of blood stains can provide important information to speculate the time of crime. The relationship between the age of blood and ...Blood stains on the fabric often appear at the scene of the crime. The age determination of blood stains can provide important information to speculate the time of crime. The relationship between the age of blood and the bending rigidity of blooded cotton fabric washed was investigated experimentally via the use of FAST-2 bending tester. The bending length of blooded fabric washed at different time was measured and the bending rigidity was calculated.The relationship between the age of blood and the bending rigidity after washing was obtained through curve fitting. The result shows that the bending rigidity of blooded fabric washed is various with the increase of the age of blood stains and this relationship can be used to speculate the age of blood stains. This method provides a new perspective for determining the bloodstain age.展开更多
The exploitation of multifunctional nanocomposites is highly desired in environmental monitoring,biosensors,and medical diagnosis.In this paper,a simple approach has been proposed to fabricate MoS2 decorated N-doped c...The exploitation of multifunctional nanocomposites is highly desired in environmental monitoring,biosensors,and medical diagnosis.In this paper,a simple approach has been proposed to fabricate MoS2 decorated N-doped carbon nanotubes(NCNTs@MoS2)hybrid composites as efficient peroxidase-like mimics.The combination of the MoS2 and N-doped carbon nanotubes(NCNTs)brings about an enhanced synergistic effect,leading to remarkably decent intrinsic peroxidase-mimic activities than that of the single components.Due to the high catalytic efficiency of the resultant NCNTs@MoS2 hybrid nanotubes as peroxidase-like mimics,a co nvenient colorimetric approach for the sensitive determination of H2 O2 and ascorbic acid have been developed with a detection limit of about 0.14μmol/L and 0.12μmol/L,respectively.The work offers a new strategy for the fabrication of peroxidase-like nanomaterials with excellent catalytic activity,which indicates great promising applications in sensitive detections in real samples.展开更多
Postmortem investigation of methamphetamine(MA)abuse is an important task in forensic pathology.The present study investigated morphological changes in the astrocytes in the parietal cerebral cortex of MA abusers.Glia...Postmortem investigation of methamphetamine(MA)abuse is an important task in forensic pathology.The present study investigated morphological changes in the astrocytes in the parietal cerebral cortex of MA abusers.Glial fibrillary acidic protein immunoreactivity in the cerebral cortex was examined in forensic autopsy cases for MA-detected group and control group.Clasmatodendrotic astrocytes(including those with swollen cell bodies and disintegrating distal processes)were frequently observed in the cerebral cortex of MA abusers.Quantitative analysis using a colour image processor showed a concomitant increase in the astrocyte area and astrocyte-to-vessel area ratio(size and number of astrocytes)in the grey matter in acute MA fatality and other MA-involved cases,although the astrocyte area(size)was also increased in cases of asphyxiation.The total astrocyte area(size)in the white matter was significantly higher in MA fatalities and asphyxia than in the other groups involving MA abusers.Those indices were independent of blood MA level,age,sex,survival or postmortem time.These observations suggest the increasing number and hypertrophic changes of astrocytes in the grey matter in MA abusers can be the outcome of long-term abuse,while disintegrating distal processes may exist only in acute fatal MA intoxication.展开更多
In recent years,many studies have been conducted in the field of firearm identification with the objective of providing an objective method of evaluating the comparison of cartridge cases.However,less attention has be...In recent years,many studies have been conducted in the field of firearm identification with the objective of providing an objective method of evaluating the comparison of cartridge cases.However,less attention has been paid to the objective evaluation of bullet comparisons.In this study,1000 registered Chinese Norinco QSZ-92 pistols were used,and a database of 2996 bullets was constructed.Both the receiver operating characteristic(ROC)curve and the score-based likelihood ratio method were used to objectively evaluate the similarity scores derived by the EvofinderVR system.The results indicate that this system has excellent ability to discriminate between the selected pistols.This paper proposes an objective evaluation method,which serves as a response to the ongoing debates regarding the foundation of the discipline.展开更多
The selection of minutiae is a critical part of the analysis phase within the fingerprint identification methodology,known as analysis-comparison-evaluation-verification.This study assessed the accuracy and reliabilit...The selection of minutiae is a critical part of the analysis phase within the fingerprint identification methodology,known as analysis-comparison-evaluation-verification.This study assessed the accuracy and reliability of the minutiae selections of 92 Chinese fingerprint examiners during the analysis phase,absent an exemplar print,of the fingerprint identification process.Specifically,we measured the accuracy(trueness)of their annotation of minutiae,and we measured their reliability which is the reproducibility and repeatability in their annotations in one complex mark by using R software.We observed significant variation within inter-and intra-examiner annotations of the minutiae.We saw no statistically significant differences for the variability of minutiae annotations based on the participant’s sex or years of experience.展开更多
The specificity of marks was evaluated by differences between marks left by the same firearm(within variability)and differences between marks left by different firearms(between variability).The within variability and ...The specificity of marks was evaluated by differences between marks left by the same firearm(within variability)and differences between marks left by different firearms(between variability).The within variability and between variability of firing pin impressions and breech face marks on cartridge cases from over 3070 consecutive firings of a Chinese Norinco QSZ‑929 mm pistol were investigated based on the automated ballistic identification system Evofinder®.The first 20 cartridge cases and one random specimen out of every set of 10 consecutive cartridge cases of the remaining 3050 cases were entered into the Evofinder®system.Thus,325 cartridges fired from the same pistol were used to estimate the within variability.Then,88 cartridges fired from 88 different pistols of the same model(one cartridge each)were used to estimate the between variability.This study established a database containing 413 cartridges.We used the 325 cartridges fired from the same pistol as a correlation baseline in the database.Both firing pin and breech scores and gaps between these scores were used to analyze the variability.In the score evaluation process,a likelihood ratio system was used to evaluate the likelihood ratio performance.The Evofinder®system correctly discriminated the matches,and the likelihood ratios provided strong support for the true state of the hypothesis.In addition,we found that the score gap was usually greater than the other score differences by more than 1000%in firing pin list and 100%in the breech list.Further analysis of the score and gap can help examiners use the Evofinder®system more efficiently.展开更多
A new kind of bifunctional magnetic-fluorescent nanoparticles(NPs)with abundant carboxyls on the surface has been prepared by covalently combining glutathiose(GSH)-modified CdTe quantum dots(QDs)with Fe3O4@SiO2NPs.The...A new kind of bifunctional magnetic-fluorescent nanoparticles(NPs)with abundant carboxyls on the surface has been prepared by covalently combining glutathiose(GSH)-modified CdTe quantum dots(QDs)with Fe3O4@SiO2NPs.The silica-coated Fe3O4NPs were functionalized with amino groups by(3-aminopropyl)triethoxysilane to provide Fe3O4@SiO2-NH2NPs,which was then chemically conjugated with GSH-modified CdTe QDs to form bifunctional magnetic-fluorescent NPs,Fe3O4@SiO2-NH-CO-CdTe-QDs NPs.The properties and morphologies of Fe3O4@SiO2-NH-CO-CdTe-QDs NPs were investigated by FTIR,X-ray diffraction,transmission electron microscopy(TEM),absorption and fluorescence spectroscopy and vibrating sample magnetometry.TEM images display that Fe3O4@SiO2-NH-CO-CdTe-QDsNPs possess spherical core-shell structure with a uniform size about 50 nm.The bifunctional NPs were found to exhibit good magnetic and strong fluorescent properties favorable for their application in the detection of latent fingerprints.Furthermore,the carboxyls on the surface of NPs have good absorptions with water in air and the residues of fingerprints so as to not only avoid dust flying to protect the health of operators,but also improve the efficiency of detection.展开更多
基金Opening Project of Shanghai Key Laboratory of Crime Scene Evidence,China(No.2014243)Fundamental Research Funds for the Central Universities,China
文摘Blood stains on the fabric often appear at the scene of the crime. The age determination of blood stains can provide important information to speculate the time of crime. The relationship between the age of blood and the bending rigidity of blooded cotton fabric washed was investigated experimentally via the use of FAST-2 bending tester. The bending length of blooded fabric washed at different time was measured and the bending rigidity was calculated.The relationship between the age of blood and the bending rigidity after washing was obtained through curve fitting. The result shows that the bending rigidity of blooded fabric washed is various with the increase of the age of blood stains and this relationship can be used to speculate the age of blood stains. This method provides a new perspective for determining the bloodstain age.
基金financial support by the Natural Science Foundation of Shanghai City(No.18ZR1416400)the National Natural Science Foundation of China(No.21305086)Science and Technology Development Fund of Shanghai Municipal Public Security Bureau(No.2018003)。
文摘The exploitation of multifunctional nanocomposites is highly desired in environmental monitoring,biosensors,and medical diagnosis.In this paper,a simple approach has been proposed to fabricate MoS2 decorated N-doped carbon nanotubes(NCNTs@MoS2)hybrid composites as efficient peroxidase-like mimics.The combination of the MoS2 and N-doped carbon nanotubes(NCNTs)brings about an enhanced synergistic effect,leading to remarkably decent intrinsic peroxidase-mimic activities than that of the single components.Due to the high catalytic efficiency of the resultant NCNTs@MoS2 hybrid nanotubes as peroxidase-like mimics,a co nvenient colorimetric approach for the sensitive determination of H2 O2 and ascorbic acid have been developed with a detection limit of about 0.14μmol/L and 0.12μmol/L,respectively.The work offers a new strategy for the fabrication of peroxidase-like nanomaterials with excellent catalytic activity,which indicates great promising applications in sensitive detections in real samples.
基金funded by Natural Science Foundation of Guangdong Province[Grant Number 2015A030313110]Shanghai Key Lab of Forensic Medicine[Grant Number KF1503].
文摘Postmortem investigation of methamphetamine(MA)abuse is an important task in forensic pathology.The present study investigated morphological changes in the astrocytes in the parietal cerebral cortex of MA abusers.Glial fibrillary acidic protein immunoreactivity in the cerebral cortex was examined in forensic autopsy cases for MA-detected group and control group.Clasmatodendrotic astrocytes(including those with swollen cell bodies and disintegrating distal processes)were frequently observed in the cerebral cortex of MA abusers.Quantitative analysis using a colour image processor showed a concomitant increase in the astrocyte area and astrocyte-to-vessel area ratio(size and number of astrocytes)in the grey matter in acute MA fatality and other MA-involved cases,although the astrocyte area(size)was also increased in cases of asphyxiation.The total astrocyte area(size)in the white matter was significantly higher in MA fatalities and asphyxia than in the other groups involving MA abusers.Those indices were independent of blood MA level,age,sex,survival or postmortem time.These observations suggest the increasing number and hypertrophic changes of astrocytes in the grey matter in MA abusers can be the outcome of long-term abuse,while disintegrating distal processes may exist only in acute fatal MA intoxication.
基金This study received funding from the Opening Project of Shanghai Key Laboratory of Crime Scene Evidence[grant number 2018XCWZK18].
文摘In recent years,many studies have been conducted in the field of firearm identification with the objective of providing an objective method of evaluating the comparison of cartridge cases.However,less attention has been paid to the objective evaluation of bullet comparisons.In this study,1000 registered Chinese Norinco QSZ-92 pistols were used,and a database of 2996 bullets was constructed.Both the receiver operating characteristic(ROC)curve and the score-based likelihood ratio method were used to objectively evaluate the similarity scores derived by the EvofinderVR system.The results indicate that this system has excellent ability to discriminate between the selected pistols.This paper proposes an objective evaluation method,which serves as a response to the ongoing debates regarding the foundation of the discipline.
基金supported by the National Natural Science Foundation of China[grant number 71371188]the Shang-hai Key Laboratory of Crime Scene Evidence[grant number 2016XCWZK08].
文摘The selection of minutiae is a critical part of the analysis phase within the fingerprint identification methodology,known as analysis-comparison-evaluation-verification.This study assessed the accuracy and reliability of the minutiae selections of 92 Chinese fingerprint examiners during the analysis phase,absent an exemplar print,of the fingerprint identification process.Specifically,we measured the accuracy(trueness)of their annotation of minutiae,and we measured their reliability which is the reproducibility and repeatability in their annotations in one complex mark by using R software.We observed significant variation within inter-and intra-examiner annotations of the minutiae.We saw no statistically significant differences for the variability of minutiae annotations based on the participant’s sex or years of experience.
基金This work has received funding from the Opening Project of Shanghai Key Laboratory of Crime Scene Evidence(2018XCWZK18).
文摘The specificity of marks was evaluated by differences between marks left by the same firearm(within variability)and differences between marks left by different firearms(between variability).The within variability and between variability of firing pin impressions and breech face marks on cartridge cases from over 3070 consecutive firings of a Chinese Norinco QSZ‑929 mm pistol were investigated based on the automated ballistic identification system Evofinder®.The first 20 cartridge cases and one random specimen out of every set of 10 consecutive cartridge cases of the remaining 3050 cases were entered into the Evofinder®system.Thus,325 cartridges fired from the same pistol were used to estimate the within variability.Then,88 cartridges fired from 88 different pistols of the same model(one cartridge each)were used to estimate the between variability.This study established a database containing 413 cartridges.We used the 325 cartridges fired from the same pistol as a correlation baseline in the database.Both firing pin and breech scores and gaps between these scores were used to analyze the variability.In the score evaluation process,a likelihood ratio system was used to evaluate the likelihood ratio performance.The Evofinder®system correctly discriminated the matches,and the likelihood ratios provided strong support for the true state of the hypothesis.In addition,we found that the score gap was usually greater than the other score differences by more than 1000%in firing pin list and 100%in the breech list.Further analysis of the score and gap can help examiners use the Evofinder®system more efficiently.
基金supported by National Key Research and Development Program of China(213 project)National Basic Research Program of China(2015CB931900)+4 种基金National Science Foundation for Distinguished Young Scholars(51825304)the National Natural Science Foundation of China(21632009,21674124,21704110)Strategic Priority Research Program of Chinese Academy of Sciences(XDB20000000)Shanghai Scientific and Technological Innovation Project(16DZ1205600,16JC1402500,17DZ1205401,17DZ1205402,18JC1410600,18JC1415500,18ZR1448600)Opening Project of Shanghai Key Laboratory of Crime Scene Evidence(2017XCWZK24,2015XCWZK15)
文摘A new kind of bifunctional magnetic-fluorescent nanoparticles(NPs)with abundant carboxyls on the surface has been prepared by covalently combining glutathiose(GSH)-modified CdTe quantum dots(QDs)with Fe3O4@SiO2NPs.The silica-coated Fe3O4NPs were functionalized with amino groups by(3-aminopropyl)triethoxysilane to provide Fe3O4@SiO2-NH2NPs,which was then chemically conjugated with GSH-modified CdTe QDs to form bifunctional magnetic-fluorescent NPs,Fe3O4@SiO2-NH-CO-CdTe-QDs NPs.The properties and morphologies of Fe3O4@SiO2-NH-CO-CdTe-QDs NPs were investigated by FTIR,X-ray diffraction,transmission electron microscopy(TEM),absorption and fluorescence spectroscopy and vibrating sample magnetometry.TEM images display that Fe3O4@SiO2-NH-CO-CdTe-QDsNPs possess spherical core-shell structure with a uniform size about 50 nm.The bifunctional NPs were found to exhibit good magnetic and strong fluorescent properties favorable for their application in the detection of latent fingerprints.Furthermore,the carboxyls on the surface of NPs have good absorptions with water in air and the residues of fingerprints so as to not only avoid dust flying to protect the health of operators,but also improve the efficiency of detection.
