Detection of humidity-treated aged latent prints using cyanoacrylate fuming and a reflected ultraviolet imaging system (RUVIS)

For the past several decades, challenges in the detection and collection of latent prints exposed to harsh environmental conditions have inspired research in pretreatment methods prior to the application of chemical, physical, or optical-based enhancement techniques. Some of the difficulties associated with processing degraded latent prints are attributed to dehydration, alterations in chemical composition, and physical disturbance of ridge detail. This study seeks to investigate the effectiveness of humidity, cyanoacrylate fuming method (CFM), and a reflected ultraviolet imaging system (RUVIS) on the detection and collection of aged latent palmprints. Prints were exposed to air flow and ultraviolet (UV) light for a period of 0 to 28 days, and subsequently treated with either cool or warm humidity and CFM. RUVIS was then utilized to detect and capture friction ridge detail after each treatment step. Improvements in RUVIS detection between treatments were evaluated based on four response factors: minutiae count, percent print recovery, ridge thickness and contrast. By measuring these factors, each latent print photograph was able to be converted to quantifiable data to facilitate statistical analysis of potential differences or improvements between treatments. The results demonstrate that the application of 80% relative humidity successfully revived aged latent palmprints across all factors. The combined effect of humidity followed v by CFM treatment and RUVIS detection was greatest for minutiae count and ridge thickness, while percent print recovery and contrast demonstrated more modest improvements when compared to control prints. Additionally, cool temperature treatments outperformed warm temperature treatments across all factors except contrast. The data therefore suggest that to achieve print rejuvenation and overall improvements in RUVIS detection, combined cool humidity and CFM is more effective than humidity alone. The data also indicate a potential correlation between temperature treatments and latent print age. Warm humidity combined with CFM appeared to best enhance RUVIS images on fresher prints of a few days to one week old, while cool humidity and CFM appeared to maximally enhance RUVIS images on prints of several weeks old

Optimization of the fabrication parameters for SERS-active forensic evidence swabs

Currently, in the forensic field there is a need for development to improve biological evidence screening. Although, biological evidence screening is not required for DNA analysis it can give insight for crime scene reconstruction therefore providing valuable forensic evidence. Many current screening tests have several limitations such as low specificity, lack of sensitivity and sample destruction. The proposed research introduces a method to collect and identify body fluid that is not only reliable but non-destructive to the sample. This can be achieved by fabrication of SERS-active forensic swabs via a silver nanoparticle synthesis. The modified swabs allow for rapid sample identification via surfaced enhance Raman spectroscopy. Several studies were performed to further enhance the synthesis reaction. A multi-point Raman measurement method was developed for Raman intensity comparison between varying synthesis conditions. Surface coverage of swab fibers and total mass of silver on swabs was also analyzed. A synthesis reaction at 80 ºC for 90 minutes was found to be the optimal parameters however, additional research may be needed to confirm these results. Lastly, the effects of silver contamination on DNA extraction and quantification were assessed. It was also concluded that the SERS-active forensic evidence swabs performed just as well as plain swabs when used for DNA extraction and quantification

A critical review of the current state of forensic science knowledge and its integration in legal systems

Forensic science has a significant historical and contemporary relationship with the criminal justice system. It is a relationship between two disciplines whose origins stem from different backgrounds. It is trite that effective communication assist in resolving underlying problems in any given context. However, a lack of communication continues to characterise the intersection between law and science. As recently as 2019, a six-part symposium on the use of forensic science in the criminal justice system again posed the question on how the justice system could ensure the reliability of forensic science evidence presented during trials. As the law demands finality, science is always evolving and can never be considered finite or final. Legal systems do not always adapt to the nature of scientific knowledge, and are not willing to abandon finality when that scientific knowledge shifts. Advocacy plays an important role in the promotion of forensic science, particularly advocacy to the broader scientific community for financial support, much needed research and more testing. However, despite its important function, advocacy should not be conflated with science. The foundation of advocacy is a cause; whereas the foundation of science is fact. The objective of this research was to conduct a qualitative literature review of the field of forensic science; to identify gaps in the knowledge of forensic science and its integration in the criminal justice system. The literature review will provide researchers within the field of forensic science with suggested research topics requiring further examination and research. To achieve its objective, the study critically analysed the historical development of, and evaluated the use of forensic science evidence in legal systems generally, including its role regarding the admissibility or inadmissibility of the evidence in the courtroom. In conclusion, it was determined that the breadth of forensic scientific knowledge is comprehensive but scattered. The foundational underpinning of the four disciplines, discussed in this dissertation, has been put to the legal test on countless occasions. Some gaps still remain that require further research in order to strengthen the foundation of the disciplines. Human influence will always be present in examinations and interpretations and will lean towards subjective decision making.JurisprudenceD. Phil

Using Different Analytical Techniques and Synthetically Tailored Silica Nanoparticles in Drug Separations and Hydrophobicity-Based Detection Applications

The development and validation of accurate and reliable analytical methods using techniques such as capillary electrophoresis, liquid chromatography, UV-spectrophotometry, spectrofluorimetry and mass spectrometry for separation and determination of some selected drugs in different matrices are presented in the first three chapters. The developed methods were applied to the determination of these compounds in their dosage forms and/or in biological fluids such as human plasma. The stability indicating characteristics including the analysis and separation of certain drugs from their alkaline, acidic, oxidative, thermal or photolytic degradation products along with the study of the degradation kinetics were also investigated. The first chapter focuses on the liquid chromatographic methods and the second chapter covers the capillary electrophoretic methods whereas the third chapter includes the UV-spectrophotometric and spectrofluorimetric methods. On the other hand, the fourth chapter shows how functionalized silica nanoparticles can be used in achieving enhanced electrophoretic separations of selected groups of acidic and basic drugs. Finally, the fifth chapter of this dissertation presents a library of fluorescently labeled-silica nanoparticles that can be used in certain hydrophobicity-based detection applications such as fingerprint detection

Potential therapeutic alternatives for smokers with osteoarthritis – an in vitro study for preclinical application

Although the adverse effects of smoking for human musculoskeletal system have been well accepted, less attention has been paid by researchers to the relevance of cigarette smoke to the onset of osteoarthritis (OA). Here, we investigated the effects of cigarette smoke extract (CSE) on human primary chondrocyte function. In addition, we investigated whether the pharmacologic treatment of dexamethasone was beneficial to chondrocytes impaired by CSE, and if not, whether it could be substituted by other treatments, such as acetaminophen and NSAIDs. Finally, we evaluated the effects of hyaluronic acid (HA) and HA combinatory treatments (dexamethasone, acetaminophen or diclofenac) on the chondrocytes impaired by CSE, in order to determine a potential therapeutic alternative for clinical application to smokers undergoing symptomatic OA. All human tissues were obtained in accordance with the ethical approval of the University Hospital Tübingen and with patients’ written consent. Human primary chondrocytes were exposed to increasing concentrations (0%, 0.1%, 0.5%, 1%, 5%, 10%) of CSE (containing 3.6 ng/ml to 72 ng/ml nicotine and 40 ng/ml to 800 ng/ml tar). Cell viability was analyzed by resazurin conversion assay and SRB staining, matrix formation was stained using Alcian blue and Safranin-O staining. The generation of free radical was evaluated by DCFH-DA assay. Semi-quantitative RT-PCR was performed to analyze gene expressions. Our present study demonstrated that the mitochondrial activity, total protein content and the accumulation of matrix were dose- and time-dependently inhibited by CSE in primary human chondrocytes. Moreover, increased oxidative stress led to cell death by 10% CSE, which is associated with approximately smoking one pack a day. As an anti-inflammatory treatment strategy, traditional pharmacologic therapy with dexamethasone (Dex) was evaluated. Clinical doses of Dex were toxic to the cells, and long-time incubation with lower doses (4−400 μg/ml) of Dex would lead to a hypertrophic chondrocyte phenotype. To substitute dexamethasone, a clinical dosage of diclofenac (Dic) and acetaminophen (Ace) was tested on chondrocytes. Interestingly, therapeutic doses of Dic (1 μg/ml) and Ace (10 μg/ml) did not augment the detrimental effects of CSE on the overall metabolisms of chondrocytes. Additionally, a clinical dose of HA (5 mg/ml) and/or HA combined with Dic, Ace, or doses of Dex had protective effects on the CSE-exposed chondrocytes, as they significantly inhibited or trap the generation of free radical and promoted the viability and ECM accumulation of cells. Our study demonstrates that cigarette smoke induces cell death through elevating oxidative stress and demolishes cartilage formation. Intra-articular (IA) injection of HA combined with therapeutic doses of analgesic/anti-inflammatory agents (Ace or Dic) could reverse the detrimental effects of CSE on primary human chondrocytes, thus opening up potential therapeutic alternatives in treating smokers to suffering from symptomatic OA