Search Results (15)

Background/Objectives: Over the past few decades, controlled substance abuse in drug-facilitated sexual assaults (DFSAs) has significantly increased worldwide, leading to an urgency to develop rapid and selective drug detection methods for field use (i.e., on-spot detection). Currently, techniques for detecting DFSA drug-associated samples are laborious and require skilled personnel to analyze/interpret the results. Moreover, most DFSA-associated drugs have a short half-life, making them more challenging to detect promptly. For instance, the timely detection of gamma-hydroxybutyrate (GHB) has been of ultimate concern for decades due to its fast elimination from the body. This study describes the development of a fluorescent ionic liquid nanosensor that can be used to rapidly detect GHB in the field. Methods: Trihexyltetradecylphosphonium fluorescein (THP₂FL) ionic liquid was synthesized and evaluated for its potential application in detecting GHB. THP₂FL nanoparticles in deionized water were synthesized with a size of 199 nm by a reprecipitation method. Results: The addition of GHB to THP₂FL nanoparticles resulted in up to a 60% increase in fluorescence intensity and a 79% increase in absorbance. These results suggest potential applications for using the fluorescent THP₂FL nanoparticles to detect GHB. The sensor’s selectivity was tested on compounds structurally similar to GHB, and the results showed that 1,4-butanediol (a precursor of GHB) is a potentially interfering species. Conclusion: This fluorescent technique allows for field deployable sensors, which would benefit screening GHB onsite. Full article

Drink spiking is a significant public safety issue, often linked to crimes such as theft and sexual assault. The detection of drugs used in these incidents is challenging due to the low concentrations (<ng) and complex matrices involved. This review explores the application of gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) to identify drugs in spiked beverages. GC-MS offers high sensitivity and specificity, and is capable of detecting drugs at ng/mL levels and distinguishing between compounds with similar structures. This review highlights the advantages of GC-MS, including its ability to simultaneously analyze multiple substances and provide detailed molecular information. Various methods for detecting gamma-hydroxybutyrate (GHB), benzodiazepines, and other drugs in beverages are discussed, emphasizing the importance of derivatization to enhance their volatility and the method’s chromatographic performance. The paper also addresses the challenges of analyzing complex beverage matrices and the need for continuous improvement in detection techniques to keep pace with the evolving drug market. Overall, GC and GC-MS are powerful tools for forensic analysis in drink spiking cases, offering reliable and accurate results, which are essential for legal and investigative processes. Full article

This study reports new types of passive mode-locked Er-doped fiber laser (EDFL) based on a segment of doped fiber saturable absorber (DFSA) with Tm/Ho-doped fiber (THDF), Yb-doped fiber (YDF), and Er-doped fiber (EDF). By employing THDF-SA, a bright pulse sequence with a fundamental repetition rate of 17.86 MHz was obtained. In addition, various mode-locked output states, including dark pulses, dark–bright pulse pairs, bright–dark pulse pairs, and second-harmonic pulses, were obtained through polarization modulation and gain modulation, and the orthogonality of dark–bright pulses in both polarization directions was verified. Furthermore, using EDF-SA and YDF-SA, dark pulses and dark–bright pulses were obtained. A comparison of the three experiments revealed that THDF-SA effectively reduces the mode-locked threshold and improves the average output power. Compared with bright pulses, dark pulses offer several advantages such as resisting noise, increasing propagation speed, and suppressing nonlinear scattering (such as pulse-intrinsic Raman scattering); thus, the EDFL can find broad application in long-distance transmission, precision measurement, and other fields. Full article

Per- and Polyfluoroalkyl Substances (PFAS) bioaccumulate in the human body, presenting potential health risks and cellular toxicity. Their transport mechanisms and interactions with tissues and the circulatory system require further investigation. This study investigates the interaction mechanisms of six PFAS with Human Serum Albumin (HSA) using multi-spectroscopy, DFT and a molecular dynamics approach. Multi-spectral analysis shows that perfluorononanoic acid (PFNA) has the best binding capabilities with HSA. The order of binding constants (298 K) is as follows: “Perfluorononanoic Acid (PFNA, 7.81 × 10⁶ L·mol⁻¹) > Perfluoro-2,5-dimethyl-3,6-dioxanonanoic Acid (HFPO-TA, 3.70 × 10⁶ L·mol⁻¹) > Perfluorooctanoic Acid (PFOA, 2.27 × 10⁵ L·mol⁻¹) > Perfluoro-3,6,9-trioxadecanoic Acid (PFO3DA, 1.59 × 10⁵ L·mol⁻¹) > Perfluoroheptanoic Acid (PFHpA, 4.53 × 10³ L·mol⁻¹) > Dodecafluorosuberic Acid (DFSA, 1.52 × 10³ L·mol⁻¹)”. Thermodynamic analysis suggests that PFNA and PFO3DA’s interactions with HSA are exothermic, driven primarily by hydrogen bonds or van der Waals interactions. PFHpA, DFSA, PFOA, and HFPO-TA’s interactions with HSA, on the other hand, are endothermic processes primarily driven by hydrophobic interactions. Competitive probe results show that the main HSA–PFAS binding site is in the HSA structure’s subdomain IIA. These findings are also consistent with the findings of molecular docking. Molecular dynamics simulation (MD) analysis further shows that the lowest binding energy (−38.83 kcal/mol) is fund in the HSA–PFNA complex, indicating that PFNA binds more readily with HSA. Energy decomposition analysis also indicates that van der Waals and electrostatic interactions are the main forces for the HSA–PFAS complexes. Correlation analysis reveals that DFT quantum chemical descriptors related to electrostatic distribution and characteristics like ESP and ALIE are more representative in characterizing HSA–PFAS binding. This study sheds light on the interactions between HSA and PFAS. It guides health risk assessments and control strategies against PFAS, serving as a critical starting point for further public health research. Full article

Analyzing urine is common in drug-facilitated sexual assault cases if the analysis of blood is not optimal. The efficient enzymatic pretreatment of urine is important for cleaving glucuronides and improving the detection of the parent drug. The aim was to investigate the efficiency of three β-glucuronidases on eleven glucuronides relevant to DFSA at different incubation periods and temperatures. Human drug-free urine was fortified with 11 glucuronides, hydrolyzed with either β-glucuronidase/arylsulfatase (Helix Pomatia), recombinant β-glucuronidase B-One™ or recombinant β-glucuronidase BGTurbo™ and incubated for 5, 10, 60 min, 18 h and 24 h at 20 °C/40 °C/55 °C before UHPLC–MS/MS analysis. The stability of 141 drugs and metabolites relevant to DFSA was investigated by incubating fortified urine under the same hydrolysis conditions. B-One™ showed efficient hydrolysis (>90%) of most glucuronides in 5 min at all temperatures, while BGTurbo™ showed a similar efficiency (>90%), but the optimal temperature (20–55 °C) and incubation time (5–60 min) varied among analytes. The β-glucuronidase/arylsulfatase had the lowest efficiency and required the longest incubation (24 h) at 40–55 °C. The stability of 99% of 141 drugs and metabolites was not affected by incubation at 20–55 °C for 24 h. Recombinant enzymes show promising results for the simple and efficient hydrolysis of a broad panel of glucuronides relevant for DFSA. Full article

The need for providing rapid and, possibly, on-the-spot analytical results in the case of intoxication has prompted researchers to develop rapid, sensitive, and cost-effective methods and analytical devices suitable for use in nonspecialized laboratories and at the point of need (PON). In recent years, the technology of paper-based microfluidic analytical devices (μPADs) has undergone rapid development and now provides a feasible, low-cost alternative to traditional rapid tests for detecting harmful compounds. In fact, µPADs have been developed to detect toxic molecules (arsenic, cyanide, ethanol, and nitrite), drugs, and drugs of abuse (benzodiazepines, cathinones, cocaine, fentanyl, ketamine, MDMA, morphine, synthetic cannabinoids, tetrahydrocannabinol, and xylazine), and also psychoactive substances used for drug-facilitated crimes (flunitrazepam, gamma-hydroxybutyric acid (GHB), ketamine, metamizole, midazolam, and scopolamine). The present report critically evaluates the recent developments in paper-based devices, particularly in detection methods, and how these new analytical tools have been tested in forensic and clinical toxicology, also including future perspectives on their application, such as multisensing paper-based devices, microfluidic paper-based separation, and wearable paper-based sensors. Full article

A cross-sectional study was conducted that describes the characteristics of sexual violence episodes related to the intake of alcohol and drugs observed among women that turned to the “Centro Soccorso Violenza Sessuale” (SVS) of the Sant’Anna Hospital in Turin between 1 January 2008, and 31 December 2017. Two hundred twenty-two patients were enrolled, 25 of which were minors, 141 were Italians, and most of them knew their aggressor and were raped in a private home. One hundred and fifty-five of them declared to the healthcare personnel to have taken alcoholic substances and/or drugs in conjunction with the event (86 reported having drunk alcohol, 36 having taken drugs and 33 disclosed both alcohol and drug abuse). If the woman knew her abuser, alcohol consumption was described as voluntary in more than 80% of cases, while in relation to drugs the consumption was equally voluntary or fraudulent. About 73% of women who reported having drunk alcohol just had amnesia or amnesia related to other symptoms, while amnesia was present in about 63% of women who reported only drug use. Physicians observed physical injuries on 156 women. Patients who reported to have assumed alcohol presented a significantly higher risk to suffer any physical injury and have a significantly increased risk to suffer injuries to their head and/or neck. The results obtained underline how even in Northern Italy alcohol intake represents the most widespread psychoactive substance in case of drug-facilitated sexual assault. There is therefore a need to promote education and prevention campaigns among citizens, especially among the youngest. Full article

In the present work, a fast, relatively cheap, and green analytical strategy to identify and quantify the fraudulent (or voluntary) addition of a drug (alprazolam, the API of Xanax^®) to an alcoholic drink of large consumption, namely gin and tonic, was developed using coupling near-infrared spectroscopy (NIR) and chemometrics. The approach used was both qualitative and quantitative as models were built that would allow for highlighting the presence of alprazolam with high accuracy, and to quantify its concentration with, in many cases, an acceptable error. Classification models built using partial least squares discriminant analysis (PLS-DA) allowed for identifying whether a drink was spiked or not with the drug, with a prediction accuracy in the validation phase often higher than 90%. On the other hand, calibration models established through the use of partial least squares (PLS) regression allowed for quantifying the drug added with errors of the order of 2–5 mg/L. Full article

A guideline called FRAMM, which is an acronym in Swedish for the most important parts of this guideline, namely “fluoride”, “advice”, “arena”, “motivation” and “diet”, was implemented in 2008 in the Västra Götaland Region in Sweden. This guideline included fluoride varnish applications performed at school twice a year at six-monthly intervals for all 12- to 15-year-olds, together with lessons on oral health. The aim of this analysis was to estimate the long-term cost-effectiveness, using prognostic calculations, of the FRAMM Guideline for 12- to 15-year-olds, compared with routine care, until the participants were 23 years old. A cost-effectiveness analysis was performed from a health care perspective, based on four years of verified data and seven years of prognosis. Data from FRAMM were combined with cost data from price lists in Sweden. The cost-effectiveness was analyzed by relating the difference in costs to the difference in the number of approximal surfaces with fillings and/or dentin lesions (DFSa). The analysis shows that FRAMM was considered dominant compared to the controls in all alternative scenarios, hence costs were prognosed to be lowered and outcomes were prognosed to be improved. A dental health program like the FRAMM Guideline with fluoride varnish during the caries risk period from 12 to 15 years is predicted to be cost-effective in the longer perspective. To further study the actual long-term caries increment after a preventive dental health program would be of great interest to verify these results. Full article

The increase in the number of drug-facilitated sexual assault (DFSA) cases in recent years has become a major concern. Consequently, there is a need to develop methods for the real-time detection of these substances. We report herein a colorimetric chemosensor for the real-time in situ detection of the “date rape” drug GHB. The sensor is based on gold nanoparticles functionalized with both a 2-aminonaphthoxazole and phenanthroline derivative. Its ability to act as “naked-eye” colorimetric sensor for the detection of the drug in soft drinks and alcoholic beverages was studied. The detection process is based on the double recognition of both the hydroxyl and the carboxylate groups present in GHB, which triggers the aggregation of the AuNPs, with the resulting change in the color of the solution. Full article

The conviction rate in drug facilitated sexual assault (DFSA) cases is known to be very low. In addition, the potential impact of toxicological results on the case is often not well understood by the judicial authorities. The aims of this study were (1) to obtain more knowledge concerning the prevalence of incapacitating substances in DFSA cases, (2) to create a more efficient DFSA analysis strategy taking background information into account, and (3) to evaluate the potential impact of systematic toxicological analysis (STA) on the final judicial outcome. This small-scale epidemiological study (n = 79) demonstrates that ‘commonly-used’ illicit drugs, psychoactive medicines and ethanol are more prevalent in DFSA cases in contrast to the highly mediatized date rape drugs. Additionally, via case examples, the interest of performing STA—to prove incapacitation of the victim—in judicial procedures with mutual-consent discussions has been demonstrated as it led to increased convictions. However, more attention has to be paid to ensure a short sampling delay and to get more accurate information from the medical treatment of the alleged victim. This will improve the interpretation of the toxicological analysis and thus its applicability in a DFSA case. The future is multi-disciplinary and will certainly lead to an efficient and more cost-effective DFSA approach in which STA can impact the final judgment. Full article

The current growing demand for low-cost edge devices to bridge the physical–digital divide has triggered the growing scope of Radio Frequency Identification (RFID) technology research. Besides object identification, researchers have also examined the possibility of using RFID tags for low-power wireless sensing, localisation and activity inference. This paper focuses on passive UHF RFID sensing. An RFID system consists of a reader and various numbers of tags, which can incorporate different kinds of sensors. These sensor tags require fast anti-collision protocols to minimise the number of collisions with the other tags sharing the reader’s interrogation zone. Therefore, RFID application developers must be mindful of anti-collision protocols. Dynamic Frame Slotted Aloha (DFSA) anti-collision protocols have been used extensively in the literature because EPCglobal Class 1 Generation 2 (EPC C1G2), which is the current communication protocol standard in RFID, employs this strategy. Protocols under this category are distinguished by their policy for updating the transmission frame size. This paper analyses the frame size update policy of DFSA strategies to survey and classify the main state-of-the-art of DFSA protocols according to their policy. Consequently, this paper proposes a novel policy to lower the time to read one sensor data packet compared to existing strategies. Next, the novel anti-collision protocol Fuzzy Frame Slotted Aloha (FFSA) is presented, which applies this novel DFSA policy. The results of our simulation confirm that FFSA significantly decreases the sensor tag read time for a wide range of tag populations when compared to earlier DFSA protocols thanks to the proposed frame size update policy. Full article

This paper models and evaluates three FSA-based (Frame Slotted ALOHA) MAC (Medium Access Control) protocols, namely, FSA-ACK (FSA with ACKnowledgements), FSA-FBP (FSA with FeedBack Packets) and DFSA (Dynamic FSA). The protocols are modeled using an AMC (Absorbing Markov Chain), which allows to derive analytic expressions for the average packet delay, as well as the energy consumption of both the network coordinator and the end-devices. The results, based on computer simulations, show that the analytic model is accurate and outline the benefits of DFSA. In terms of delay, DFSA provides a reduction of 17% (FSA-FBP) and 32% (FSA-ACK), whereas in terms of energy consumption DFSA provides savings of 23% (FSA-FBP) and 28% (FSA-ACK) for the coordinator and savings of 50% (FSA-FBP) and 24% (FSA-ACK) for end-devices. Finally, the paper provides insights on how to configure each FSA variant depending on the network parameters, i.e., depending on the number of end-devices, to minimize delay and energy expenditure. This is specially interesting for massive data collection in IoT (Internet-of-Things) scenarios, which typically rely on FSA-based protocols and where the operation has to be optimized to support a large number of devices with stringent energy consumption requirements. Full article

With the rapid development of the Internet of Things (IoT), the radio frequency identification (RFID) system becomes increasingly important. Tag identification is a basic problem of the RFID system, whose purpose is to inventory tags. However, in recent years, it requires a very short time for massive tag identification, which brings serious challenges. The traditional Aloha based anti-collision algorithms have disadvantages of either low efficiency or high complexity. Therefore, this article proposes a low complexity dynamic frame slotted Aloha (DFSA) anti-collision algorithm, named LC-DFSA. The reader can estimate the range of tag numbers according to the last frame size, the number of successful slots and the ratio of idle slots. Then the optimal frame size can be calculated. Complexity analysis is deployed in this article, and we validate the correctness of the analysis. Through our simulations, LC-DFSA outperforms other schemes in both the average access efficiency and the algorithm complexity. It also can be conveniently applied to engineering implementations. Full article

The Industrial Internet of Things (IIoT) is often presented as a concept that is significantly changing industry, yet continuous improvements in the identification and automation of objects are still required. Such improvements are related to communication speed, security, and reliability, critical attributes for industrial environments. In this context, the radio-frequency identification (RFID) systems present some issues related to frame collision when there are several tags transmitting data. The dynamic framed-slotted ALOHA (DFSA) is a widely used algorithm to solve collision problems in RFID systems. DFSA dynamically adjusts the frame length based on estimations of the number of labels that have competed for slots in the previous frame. Thus, the accuracy of the estimator is directly related to the label identification performance. In the literature, there are several estimators proposed to improve labels identification accuracy. However, they are not efficient when considering a large tag population, requiring a considerable amount of computational resources to perform the identification. In this context, this work proposes an estimator, which can efficiently identify a large number of labels without requiring additional computational resources. Through a set of simulations, the results demonstrate that the proposed estimator has a nearly ideal channel usage efficiency of 36.1%, which is the maximum efficiency of the DFSA protocol. Full article