首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 781 毫秒
1.
A classification of vascular malformations (VM) is defined in the article including a differentiation between their macroscopic and histological variations; an independently-authors-observed case of arterial-and-venous malformation (AVM) in a minor cranial-cerebral trauma (CCT) is described. Published data reflecting the forensic-and-medical value of AVM and cavernous malformations as well as of telangectasias and of arterial-and-venous fistulas in minor head traumas are analyzed. Issues of the forensic-and-medical expertise of VM and remote consequences of CCT are under consideration. VM are assessed in CCT patients with epilepsy and other pathologies. An algorithm of the forensic medical expertise of VM is suggested.  相似文献   

2.
The differentiation of inks on a questioned document can highlight a fraudulent insertion and is usually carried out by optical comparison and thin-layer chromatography (TLC). Laser desorption ionization mass spectrometry (LDI-MS) may also be used for the analysis of dyes from ink. This analytical technique was compared with a standard method of high-performance TLC (HPTLC) according to their capacity to differentiate blue ballpoint inks. Ink entries on paper from 31 blue ballpoint pens have been analyzed and their dye ink formulations compared. The pens were classified into 26 classes by LDI-MS against 18 for HPTLC. LDI-MS proved to be a more powerful method for differentiating ink formulations because it provides information about dye structures (molecular weights) and relative quantification of dye classes (peak areas). Sample preparation was minimal and analysis time was short in contrast to the more complex extraction, application, and development steps of the HPTLC method. However, only basic dyes and pigments were identified using positive mode LDI-MS, while HPTLC did yield additional information about acid dyes.  相似文献   

3.
The traditional thin-layer chromatography (TLC) is a sensitive technique frequently used in chemical analysis for semiquantitative determinations. In the last years a high-performance thin-layer chromatography system (HPTLC) has been developed. It assures quantitative determinations with direct densitometric measurements of chromatographic spots in situ on the plate. Here, we wish to report a method for the drug determination in street samples, that employs a CAMAG TLC/HPTLC Scanner Photodensitometer and a CAMAG LINOMAT III for sample application. Samples of illicit drug traffic (50 samples of street heroin and 30 samples of street cocaine) are tested and the gas-liquid chromatography (GLC) and HPTLC determinations are compared. The HPTLC method has proven to be sensitive, precise and accurate for quantitative determinations of drugs in street samples. Furthermore this method may be useful in forensic chemistry to show a "fingerprint" of each sample.  相似文献   

4.
目的研究病毒性心肌炎心肌MMP-9、TGF-β1表达与心肌纤维化的关系,探讨其在病毒性心肌炎猝死鉴定中的作用。方法筛选30例病毒性心肌炎作为实验组(18例为明确性心肌炎组,12例为界限性心肌炎组),另选10例非病毒性心肌炎作为对照组。Masson染色观察病毒性心肌炎心肌胶原增生的情况;免疫组化法检测MMP-9、TGF-β1的蛋白表达和组织定位,并用图像分析系统及统计学方法进行定量分析。结果病毒性心肌炎组心肌胶原纤维较对照组明显增多;MMP-9、TGF-β1的表达水平明显增高,MMP-9、TGF-β1的表达与心肌胶原纤维增生呈正相关。结论MMP-9、TGF-β1可能在病毒性心肌炎心肌纤维化过程中起重要作用,可以作为病毒性心肌炎猝死的辅助诊断的指标。  相似文献   

5.
The ink of pens and ink extracted from lines on white photocopier paper of 10 blue ballpoint pens were subjected to ultraviolet-visible (UV-Vis) spectroscopy, infrared (IR), and high-performance thin-layer liquid chromatography (HPTLC). The R(f) values and color tones of the bands separated by thin-layer chromatography (TLC) analysis used to classify the writing inks into three groups. The principal component analysis (PCA) investigates the pen responsible for a piece of writing, and how time affects spectroscopy of written ink. PCA can differentiate between pen ink and ink line indicates the influence of solvent extraction process on the results. The PCA loadings are useful in individualization of a questioned ink from a database. The PCA of ink lines extracted at different times can be used to estimate the time at which a questioned document was written. The results proved that the UV-Vis spectra are effective tool to separate blue ballpoint pen ink in most cases rather than IR and HPTLC.  相似文献   

6.
The transition from 2D imaging to 3D scanning in the discipline of firearms and toolmark analysis is likely to provide examiners an unprecedented view of microscopic surface topography. The digital examination of measured 3D surface topographies has been referred to as virtual microscopy (VM). The approach offers several potential advantages over traditional comparison microscopy. Like any new analytic method, VM must be validated prior to its use in a crime laboratory. This paper describes one of the first validation studies of virtual microscopy. Fifty‐six participants at fifteen laboratories used virtual microscopic tools to complete two proficiency‐style tests for cartridge case identification. All participating trained examiners correctly reported 100% of the identifications (known matches) while reporting no false positives. The VM tools also allowed examiners to annotate compared surfaces. These annotations provide insight into the types of marked utilized in comparative analysis. Overall, the results of the study demonstrate that trained examiners can successfully use virtual microscopy to conduct firearms toolmark examination and support the use of the technology in the crime laboratory.  相似文献   

7.
Stamp pad inks from different manufacturers across India have been analyzed to investigate the feasibility of Raman scattering as a tool for forensic analysis of questioned documents involving stamp inks. Nine different stamping inks were analyzed by both Raman spectroscopic and HPTLC methods. The results demonstrate the effectiveness of these methods in classifying the investigated stamping inks based on their spectral pattern and HPTLC chromatogram. Raman scattering tool was able to determine the sequence of heterogeneous intersection strokes involving a blue stamp pad ink and other writing instruments, such as ballpoint pen ink (red and black), pencil and laser printer toner. However, this method was unable to resolve the exact sequencing for the intersection strokes involving investigated stamp ink and blue ballpoint ink or gel pen ink (all colors).  相似文献   

8.
The recovery measurements in rat tissues performed via i.p. injected radioactive digoxin derivates (3H-digoxin, 125J-digoxin derivative) showed that approximately 50% of the total glycoside content will be extracted. Thus, an addition of digoxin standards to drug-free tissues may lead to false negative determinations. By comparison of the radioactivity before and after extraction the following results were obtained: Recovery from tissues 3H-digoxin 50% 125J-digoxin 40% from serum 3H-digoxin 60% added to drug free tissue homogenates 3H-digoxin 85% After i.p. application of 15 mg/kg of beta-methyldigoxin to BD9 (Berlin)-rats the resulting tissue concentrations were extracted by Amberlite XAD-2. beta-Methyldigoxin and its metabolites digoxin and digoxinbisdigitoxide could be separated and distinguished from artifacts by fluorescence detection on HPTLC-plates with a detection limit of 60 ng/spot. Concentration determined by radioimmunoassay are in satisfactory agreement with HPTLC results.  相似文献   

9.
The research reported in this series of article aimed at (1) automating the search of questioned ink specimens in ink reference collections and (2) at evaluating the strength of ink evidence in a transparent and balanced manner. These aims require that ink samples are analysed in an accurate and reproducible way and that they are compared in an objective and automated way. This latter requirement is due to the large number of comparisons that are necessary in both scenarios. A research programme was designed to (a) develop a standard methodology for analysing ink samples in a reproducible way, (b) comparing automatically and objectively ink samples and (c) evaluate the proposed methodology in forensic contexts.This report focuses on the last of the three stages of the research programme. The calibration and acquisition process and the mathematical comparison algorithms were described in previous papers [C. Neumann, P. Margot, New perspectives in the use of ink evidence in forensic science—Part I: Development of a quality assurance process for forensic ink analysis by HPTLC, Forensic Sci. Int. 185 (2009) 29–37; C. Neumann, P. Margot, New perspectives in the use of ink evidence in forensic science—Part II: Development and testing of mathematical algorithms for the automatic comparison of ink samples analysed by HPTLC, Forensic Sci. Int. 185 (2009) 38–50].In this paper, the benefits and challenges of the proposed concepts are tested in two forensic contexts: (1) ink identification and (2) ink evidential value assessment. The results show that different algorithms are better suited for different tasks. This research shows that it is possible to build digital ink libraries using the most commonly used ink analytical technique, i.e. high-performance thin layer chromatography, despite its reputation of lacking reproducibility. More importantly, it is possible to assign evidential value to ink evidence in a transparent way using a probabilistic model. It is therefore possible to move away from the traditional subjective approach, which is entirely based on experts’ opinion, and which is usually not very informative.While there is room for the improvement, this report demonstrates the significant gains obtained over the traditional subjective approach for the search of ink specimens in ink databases, and the interpretation of their evidential value.  相似文献   

10.
In this paper we describe the identification of constituents of the illicit drugs seized from different regions of eastern India by GC-MS. The constituents were identified to be heroin, acetyl morphine, morphine and acetyl codeine. Quantitative estimation of the constituents were made by GC-MS and HPTLC. In view of non-availability of the authentic samples of drugs of different origin, nothing positive can be said about the origin of illicit drug samples. The possibility of isotopic substitution, an important method for identification of source, was examined from the comparison of the intensity of different (ion) peaks 369 (heroin, m/z=369), 370, 371 and 372 using selective ion monitoring mode. No isotopic substitution in the constituents was observed. Attempts were made to identify the source of the illicit samples from heroin/acetylcodeine ratios in the way described in the literature.  相似文献   

11.
The identification of ABH antigens from compact bone tissue is known from many sources. The purpose of this study was to make a contribution to the localization of blood-group-active substances in compact bone tissue. A variety of preparation and identification methods were successfully used and compared. Samples were extracted from compact bone tissue, separated by HPTLC, and examined using the absorption-elution and PAP techniques. Additionally, the PAP technique was carried out on cryostat sections. Serologically active blood-group substances were consistently demonstrated in the organic components of the haversian canals.  相似文献   

12.
Stroma from hemolyzed erythrocytes of blood groups 0, A1, B and A1B were obtained and subjected to butanol/phosphate buffer extraction. This extract was separated using HPTLC, and the ABH and Le substances were detected on the chromatogram using the PAP technique. The staining of the bands allowed specific demonstration of the serologically active glycosphingolipids present in the ABH and Le blood group substances. The antigens of the AB0 system showed a 3- to 12-band pattern. Each of the antigens Lea and Leb presented 3 bands. The slight differences in the levels of glycosphingolipids of equal chain lengths are probably due to differences in their chemical structures.  相似文献   

13.
Blood group substances were extracted from erythrocytes of blood groups A1 and A2 and separated using HPTLC. Identification of blood group A was carried out on the chromatogramm using the PAP-technique. The specific demonstration of the serologically active glycosphingolipids allowed a comparison of the A1 and A2 blood group substance bands. The difference between the A1 and A2 Substances appears to be only a quantitative one.  相似文献   

14.
Usually, the differentiation of inks on questioned documents is carried out by optical methods and thin layer chromatography (TLC). Therefore, spectrometric methods were also proposed in forensic literature for the analysis of dyes. Between these techniques, laser desorption/ionization mass spectrometry (LDI-MS) has demonstrated a great versatility thanks to its sensitivity to blue ballpoint ink dyes and minimal sample destruction. Previous researches concentrated mostly on the LDI-MS positive mode and have shown that this analytical tool offers higher discrimination power than high performance TLC (HPTLC) for the differentiation of blue ballpoint inks. Although LDI-MS negative mode has already been applied in numerous forensic domains like the studies of works of art, automotive paints or rollerball pens, its potential for the discrimination of ballpoint pens was never studied before. The aim of the present paper is therefore to evaluate its potential for the discrimination of blue ballpoint inks. After optimization of the method, ink entries from 33 blue ballpoint pens were analyzed directly on paper in both positive and negative modes by LDI-MS. Several cationic and anionic ink components were identified in inks; therefore, pens were classified and compared according to their formulations. Results show that additional information provided by anionic dyes and pigments significantly increases the discrimination power of positive mode. In fact, it was demonstrated that classifications obtained by the two modes were, to some extent, complementary (i.e., inks with specific cationic dyes not necessarily contained the same anionic components).  相似文献   

15.
Various 9‐mm ammunitions (A1, A4, A5, ST, GS, GSb, P.E.P., SeCa, HP, PTP/s, VM, McVG, DM41, PTP, SX2, PT, and MEN frangible) were tested regarding their velocity, energy, angle of impact, and potential wound channel after penetrating a car window at 30° and 90°. Test materials were gelatine, soap, and pig cadavers. The velocities of the projectiles were between c. 288 and 430 m/ses, the energy spread between 394 and 564 J. Handgun bullets fired through vehicular side window glass lose substantial energy reducing the effectiveness of the ammunition. This effect is greater when fired at an angle of 30° compared to 90°. At a shooting angle of 90°, none of the different projectiles showed remarkable differences considering its wound ballistic features. Accuracy is maintained at a 90° angle but seriously impaired at 30°. None of the examined ammunition complied with the demanded wound channel effectiveness of 30–60 J/cm.  相似文献   

16.
Recent elections in France (2002 and 2007) and Italy (2008) were won on a law and order platform. This article asks why, and compares the strategies used by the new governments to implement their election promises. The goals are the same: to increase security and lower fear of crime levels, but there are noticeable differences in the perception of the underlying causes, such as the role played by illegal immigration. The solutions proposed also vary. France relies on increased police efficiency and more coercive legislation, whereas Italy favours almost exclusively emergency legislation including the deployment of 3500 soldiers. Prevention is not a priority in either country.  相似文献   

17.
The Electrostatic Dust Print Lifter (EDPL) and the Electrostatic Detection Apparatus(2) (ESDA(2)) were compared to determine if both processes could be used to develop footwear impressions of the same or similar quality and in what order they should be used to develop the highest quality footwear impression. The sensitivity of each technique was also evaluated. The quality of the footwear impressions developed was determined by comparing 25 individual characteristics present on the known shoe to the footwear impressions developed using each technique. The footwear impressions were made by stepping on paper placed over several different surfaces, which included: linoleum, industrial Berber carpet, nylon carpet placed over a (3/8)-in. pad, ceramic tile, cardboard, 1-in. foam, 4-in. foam, cement, asphalt, grass, and mulch. Each of the papers placed on these surfaces was developed using the EDPL before the ESDA(2) and vice versa. The sensitivity test for the ESDA(2) was conducted by processing 10 sheets of stacked paper that were stepped on with the known shoe, beginning with the top sheet. The sensitivity test for the EDPL was conducted by processing 10 sheets of paper stepped on with the known shoe in succession. This study determined the footwear impressions developed using the EDPL were of better comparative value than impressions developed with the ESDA(2). On average, 72.4% of the individual characteristics from the known impression were identified on images developed when the EDPL was used first compared with an average of 38.9% when the ESDA(2) was used first. Therefore, if only one technique is used, the EDPL should be chosen. The sensitivity test determined the ESDA(2) develops high-quality footwear impressions on only the top sheet of paper. No footwear impressions were developed on any sheets under the top sheet of paper. The sensitivity test also determined the EDPL results increase in quality as the amount of dust residue decreases on the surface.  相似文献   

18.
The current study used confirmatory factor analysis to examine the factor structures of two instruments commonly used in the assessment of competency to stand trial--the MacArthur Competence Assessment Tool--Criminal Adjudication (MacCAT-CA) and the Brief Psychiatric Rating Scale (BPRS). Results revealed support for the three-subscale factor structure of the MacCAT-CA defined by the authors of the instrument; for a slightly altered three-factor structure defined by Zapf, Skeem, and Golding (2005, Psychological Assessment, 17, 433-445); and for the four symptom clusters of the BPRS as defined by Hedlund and Vieweg (1980, Journal of Operational Psychiatry, 11, 48-63). In addition, exploratory factor analysis of all 24 items of the BPRS revealed a five-factor structure. Correlations between psychiatric symptoms, symptom clusters, and competence-related abilities were also examined using the previously identified and the newly identified factor structures of the MacCAT-CA and the BPRS. Significant relations between symptoms and psycholegal abilities are discussed.  相似文献   

19.
Despite the lack of consensus regarding the meaning or significance of race or ethnicity amongst scientists and the lay public, there are legal requirements and guidelines that dictate the collection of racial and ethnic data across a range of institutions. Legal regulations are typically created through a political process and then face varying kinds of resistance when the state tries to implement them. We explore the nature of this opposition by comparing responses from businesses, scientists, and science-oriented businesses (pharmaceutical and biotechnology companies) to U.S. state regulations that used politically derived racial categorizations, originally created to pursue civil rights goals. We argue that insights from cultural sociology regarding institutional and cultural boundaries can aid understanding of the nature of resistance to regulation. The Food and Drug Administration's guidelines for research by pharmaceutical companies imposed race categories on science-based businesses, leading to objections that emphasized the autonomy and validity of science. In contrast, similar race categories regulating first business by the Equal Employment Opportunity Commission (EEOC) and later scientific research sponsored by the National Institutes of Health (NIH) encountered little challenge. We argue that pharmaceutical companies had the motive (profit) that NIH-supported scientists lacked and a legitimate discourse (boundary work of science) that businesses regulated by the EEOC did not have. The study suggests the utility of a comparative cultural sociology of the politics of legal regulation, particularly when understanding race-related regulation and the importance of examining legal regulations for exploring how the meaning of race or ethnicity are contested and constructed in law.  相似文献   

20.
冯晓青 《河北法学》2007,25(5):19-28
全球化环境下知识产权保护存在很多值得探讨的问题。由中国政法大学民商经济法学院举办、中国政法大学民商经济法学院知识产权法研究所承办、美国Kenyon&Kenyon LLP和National Economic Research Associates,Inc.提供赞助的全球化与知识产权保护国际会议于2007年1月20—21在北京召开,近二百名国内外知识产权专家学者探讨了全球化环境下知识产权保护的一系列问题。本次会议对于推动国内外知识产权理论与实践问题的研究具有深远意义。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号