Forensic Discrimination of condom lubricants using ATR-FTIR spectroscopy in combination with chemometrics- effect of matrices, pre-coital and post-coital conditions.

The escalating rates of rape and sexual assault cases underscore the essential need to analyze associative evidence of sexual assault to ensure justice. The condom, when used during the act of sexual assault/rape, leaves behind traces of lubricant that could be instrumental in establishing the link between the victim and perpetrator. This leading evidence is crucial especially when the traditional DNA analysis is challenging owing to the lack of biological evidence. The present study employs the use of ATR FTIR spectroscopy coupled with the chemometric, to discern the chemical discrimination of condom lubricants. The study also aimed to investigate simulated real-case scenarios by analysing the effect of different matrices such as vaginal fluid, menstrual blood, and undergarment substrates (cotton, polyester and nylon) on condom traces. The difference in the spectral profile of pre-coitus and post-coitus samples was also investigated. The results of the present study are noteworthy, unveiling the efficacy of discriminating the condom lubricants of different brands and other frequently used household lubricants with 100% sensitivity, specificity, and accuracy. Condom lubricants are detected despite the presence of contaminants such as menstrual blood, and vaginal fluid, across different substrates and, in post-coital conditions. In conclusion, this study presents a comprehensive approach to analysing condom lubricants, offering a potential breakthrough in the investigation of sexual assault cases, coupled with the ability to counter false accusations.

The Simulation of Ester Lubricants and Their Application in Weak Gel Drilling Fluids.

To enhance the performance and reduce the amount of ester-based lubricants used in weak gel drilling fluids, a shear dynamics simulation under extreme pressure conditions was employed to refine the formulation of the base oil and pressure additives. The simulation results were validated using fatty acid methyl, ethyl, and butyl esters. Fatty acid methyl ester demonstrated the lowest temperature increase and the highest load-bearing capacity post-shear. The four-ball friction test revealed that methyl oleate had a coefficient of friction of 0.0018, approximately a third of that for butyl oleate, confirming the simulation's accuracy. By using methyl oleate as the base oil and oleamide as the pressure-resistant component, the optimal shear stress was achieved with a 10% addition of oleamide. A lubricant composed of 90% methyl oleate and 10% oleamide was tested and showed a coefficient of friction of 0.03 when 0.5% was added to bentonite slurry, indicating a strong lubricating film. Adding 1% of this lubricant to a low gel drilling fluid system did not affect its rheological properties, and the gel structure remained stable after seven days of aging. Field tests at the Fu86-3 well in the Jiangsu Oilfield of Sinopec confirmed that adding 1% of the ester-based lubricant to the drilling fluid significantly improved drilling efficiency, reduced drag by an average of 33%, and increased the drilling rate to 22.12 m/h. This innovation effectively prevents drilling complications and successfully achieves the objectives of enhancing efficiency.

Preload and Removal Torque of Two Different Prosthetic Screw Coatings-A Laboratory Study.

This study aimed to evaluate the effect of two coating materials, a silicone sealing gel and a polytetrafluoroethylene (PTFE) tape, on the screw preload and removal torque value (RTV) to develop strategies to prevent prosthetic screw loosening. We examined 45 complexes comprising an implant, abutment, and prosthetic screw, of which 15 samples were uncoated, 15 were coated with GapSeal® (Hager & Werken GmbH & Co., Duisburg, Germany), and 15 were coated with PTFE tape (MIARCO®, Valencia, Spain). The screws were tightened to register the preload and then untightened to register the RTV. The preload values showed a statistically significant difference only in the PTFE group, suggesting that this lubricant negatively affects the preload. The RTVs showed statistically significant differences among all groups, with the GapSeal® group and PTFE group showing the highest and lowest values, respectively. It can be concluded that the application of the PTFE tape on the screw significantly reduced the preload and RTV. The silicone sealing gel did not affect the preload but increased the RTV. Therefore, the use of GapSeal® should be considered to prevent prosthetic screw loosening, while the use of PTFE tape should be avoided.

Forensic aspects of condom evidence: Analysis, interpretation, and recent trends.

In recent years, collection and analysis of condom evidence in sexual assault investigations are becoming more common in forensic caseworks. Condom analysis can provide investigative leads or establish potential contact between the suspect and victim in the absence of DNA evidence or supplement biological evidence. Recent forensic literature shows significant advancements in the analysis of condom lubricants, including casework samples. There is an increasing trend in the use of chemometric tools for the comparison and interpretation of the results. This review highlights the advances in common analytical techniques used for the analysis of condom lubricants with a particular focus on the developments occurring in recent years, including chemometric interpretation. The analysis of reference and casework samples (swab samples, samples on skin, clothing and fingermark) are discussed separately. For casework samples, the transfer and persistence of different lubricant formulations are discussed, along with their detection with various analytical approaches. The issues with the interpretation of lubricants are also discussed in another section, with particular emphasis on samples such as personal hygiene products which have similar formulations with sexual lubricants and the interpretation of negative profiles. The current challenges in the field and prospects for future research are also discussed.

Unraveling Water-Based Lubrication with Carbon Dots of Asphaltene Origin.

Despite the lower toxicity of water-based lubricants over nonrenewable petroleum-based analogues, they face challenges in achieving widespread adoption due to low stability and inadequate friction-reduction performance. To address this, a cost-effective nanoadditive is synthesized by expansive oxidation of asphaltenes to create biocompatible asphaltene-derived carbon dots [(ACDs); 5 nm]. These ACDs exhibit excellent water redispersibility, promoting long-term friction reduction and marking the first use of an asphaltene-based system for friction reduction in water or oil. Even at low loadings (0.2-4.0 wt %), ACDs significantly reduce friction on steel surfaces (>54%) with tribofilm stability surpassing pristine carbon dots, typical carbon-based graphene quantum dots, and inorganic nanomaterials (commercial 5 and 20 nm silica). The ACDs' attributes include high negative zeta potential, considerable water uptake, varied functional groups, biocompatibility, and a nanodisc shape conducive to stable tribofilm formation through effective particle stacking. The scalable synthesis, high yield, and impressive water redispersibility of ACDs position them favorably for commercial water-based lubrication.

Variation of Soil Bacterial Communities in Forest Soil Contaminated with Chainsaw Lubricants.

Pollutants can exist in the soil for a long time and alter the bacterial community. Using lubricants to prevent the wear of chainsaw blades is necessary for thinning activities and wood harvesting. We investigated the influences of soil contamination with chainsaw lubricants on soil bacterial communities. Bio-oil, mineral oil, and recycled oil were scattered on each treatment to investigate variations in soil bacterial structure during treated periods using the Illumina MiSeq sequencing platform. The results obtained were 5943 ASVs, 5112 ASVs, and 6136 ASVs after treatment at one month, six months, and twelve months, respectively. There was a significant difference in Shannon and Simpson indices between treatments and controls. A total of 46 bacterial genera with an average relative abundance of more than 1.0% were detected in all soil samples. Massilia was the most common genus detected in control at one month, with an average relative abundance of 14.99%, while Chthoniobacter was the most abundant genus detected in bio-oil, mineral oil, and recycled oil treatments at one month, with an average relative abundance of 13.39%, 14.32%, and 10.47%, respectively. Among the three chainsaw lubricants, bio-oil and mineral oil had fewer impacts than recycled oil. The abundances of several functional bacteria groups in the bio-oil treatment were higher than in other treatments and controls. Our results indicated that different chainsaw lubricants and their time of application affected the soil bacterial community composition.

Evaluation of crude watermelon oil as lubricant in cylindrical turning of AISI 1525 steel employing Taguchi and grey relational analyses techniques.

Cutting fluids are used for cooling and lubricating the machining area of components used in manufacturing industries such as aerospace, automotive, petroleum, and heavy machinery. Mineral oils derived from petroleum are commonly utilized as cutting fluids. Mineral oil is hazardous to the health of workers and damaging to the environment. There is a need for a substitute for mineral oil. Vegetable oil is increasingly being used as a cutting fluid. Vegetable oils are easily accessible and have benefits including excellent biodegradability, resistance to fire, low humidity rates, and a low coefficient of expansion under heat. This study adopts watermelon oil as a lubricant in MQL machining of AISI 1525 steel using tungsten tools. In the experiment, the feed rate, depth of cut (DC) and spindle speed were varied using the Taguchi L9 orthogonal array. Grey relational analysis was conducted to obtain optimum cutting parameters for surface roughness, machine vibration, and cutting temperature. Hardness and microstructural analysis of the workpiece were also conducted. Results showed that vegetable oil performed much more effectively than mineral oil in most experiments. The DC was shown to be the most efficient cutting parameter after applying ANOVA analysis based on the parameters that were evaluated. Additionally, models for cutting temperature, machine vibration, and surface roughness values have been developed with accuracy between 69.73 % and 99.05 %. The hardness of the workpiece increases with an increase in diameter, which was attributed to the increase in the steel rod (workpiece) cross-sectional area and the likelihood of a more uniform stress distribution. Moreover, finer grain sizes were observed at 70 mm diameter, with the predominant presence of pearlites. These characteristics were reportedly beneficial to the material's toughness and strength.

Do sperm and lubricants gel well with each other? A systematic review.

Vaginal lubricants are commonly used to aid sexual pleasure and/or to help combat vaginal dryness and dyspareunia. Several studies have reported their impact on sperm function, however there are no published guidelines to help healthcare professionals and couples select a vaginal lubricant that is 'sperm-safe'. To address this, we conducted a literature search using both PubMed and Scopus to identify and appraise manuscripts that reported the impact of lubricants on sperm function. We did not restrict the literature search by year of publication, and we only included manuscripts that looked at the impact of vaginal lubricants on human sperm. The quality of the eligible studies was assessed using the Björndahl et al., (2016) checklist for semen analysis, as most of the studies reported the findings of a basic semen analysis. A total of 24 articles were eligible for analysis with a total of 35 vaginal lubricants (that were available to buy over the counter) being included, 2 of which studied the effect of vaginal lubricants on sperm function in vivo, and 22 being conducted in vitro. KY Jelly, PreSeed and Astroglide were most studied, with most manuscripts focussing on their impact on sperm motility. A paucity of data on most lubricants combined with methodological variations between studies and limited/no reporting on pregnancy outcomes means greater efforts are required before an evidence-based guideline can be published.

Application of high-performance liquid chromatography in determining saturates and aromatic hydrocarbons along with polars/additives in automotive finished and used lubricating oils.

Lubricating oils help an internal combustion engine function effectively by reducing friction and wear on the engine's moving parts. They typically consist of petroleum-derived base oil and various additives to achieve the desired characteristics in automotive engine oils. Determination of aromatics and polar additives in the finished and used lubricating oils is not possible with existing methods hence their development is significant from the perspectives of environment and reuse/re-refining of used lubricating oils. This study reports the development of a new HPLC method to determine additives in the finished lubricating oils and/or polars in the used engine oils. The proposed method is simple, fast (runtime of 13 min), does not require sample pre-treatment, and exhibits high precision and superior limits of detection and quantification. The method demonstrated good linear response ranging from 0.1 to 30 mass for total aromatics and 0.1 to 20 % for additives. The method validation was carried out by analyzing brand-new commercial two and four-wheeler lubricants with used automotive lubricants. Based on the proposed method, the aromatics and additives concentration ranges in the studied finished lubricants were estimated between 0.20-1.70 % (mass) and 0.20-3.50 % (mass), respectively. Similarly, for used lubricants, the aromatics and additives were estimated to be 1.00-6.10 % and 0.60-2.40 % (mass), respectively.

Thermosensitive Triblock Copolymer for Slow-Release Lubricants under Ocular Conditions.

The ocular environment is crucial for a biological lubrication system. An unstable condition of tear film may cause a series of ocular diseases due to serious friction, such as dry eye syndrome, which has drawn extensive attention nowadays. In this study, an in vitro biocompatible superlubricity system, containing thermogelling copolymers (PCGA-PEG-PCGA) and slow-release lubricant (PEG 300/Tween 80), was constructed. First, the sol-gel transition temperature and gel strength of PCGA-PEG-PCGA were adjusted based on the ocular environment by regulating the length of PCGA blocks. Furthermore, the copolymer hydrogel exhibited a reliable slow-release property within 10 days and showed low cytotoxicity. Then, the superlubricity (coefficient of friction of approximately 0.005) was achieved with its released PEG 300/Tween 80 aqueous solution at the sliding velocity range of 1-100 mm s-1 and pressure range of 10-22 kPa. However, the lubrication behaviors varied, while PEG 300 chains and Tween 80 micelles were demonstrated to form a multilayer and a single layer adsorption structure on the sliding surface, respectively. On the whole, the composite lubrication systems, especially the one composed of Tween 80, showed excellent tribological properties owing to the stable slow-release and full hydration effects under ocular conditions, which hold great potential for improving ocular lubrication and maintaining human visual health.

Synthesis of Long Chain Oxygenates via Aldol Condensation of Furfural and Acetone over Metal-Organic Frameworks.

Enormous efforts have been made to convert biomass to liquid fuels and products catalytically. Long molecules with a suitable structure are ideal precursors for fuels and value-added products. Here, a C21 oxygenate was synthesized for the first time in one step through aldol condensation of furfural and acetone over the amine-functionalized zirconium-based metal-organic framework (MOF), UiO-66-NH2. Structural changes of UiO-66-NH2 were investigated to improve the yield and evaluate the role of the ligand, cluster node, defectiveness, modulator, surface area, and textural properties on the product distribution. We demonstrate the possibility of making long-chain oxygenates without using vegetable oil-derived fatty acids toward 100% waste biomass-derived renewable fuels, lubricants, and surfactants.

Synthesis of Imidazole-Based Deep Eutectic Solvents as Solid Lubricants: Lubricated State Transition.

The controllable character of the melting point of deep eutectic solvents (DESs) makes it easy to realize lubricated state transitions and produce excellent lubricating properties during friction. In this work, a series of novel imidazole-based DESs were synthesized to present a room-temperature solid state by shifting its eutectic point. Tribological test results show that the wear volume of these DESs decreases as the alkyl chains of the hydrogen bond donors increase. A proper deviation of the eutectic point in DESs produces stable lubricating properties. The present work provides a novel and simple method to prepare solid lubricants and enriches the use of DESs as lubricants. Simultaneously, the method expected to replace the use of conventional cutting fluids.

Comparative Studies on the Organogel Formation of a Polyester in Three Different Base Oils by X-ray Analysis, Rheology and Infrared Spectroscopy.

High-performance greases typically consist of a base oil and polyurea as a thickener material. To date, few alternatives to polyureas have been investigated. Polyesters could be one such alternative; however, little is known about the gelation of such polyesters because, unlike polyureas, they cannot form hydrogen bonds between the polymer chains. Here, we present studies on the gel formation of a polyester based thickener poly(hexane dodecanoate) with 1-octanol endgroups in three different base oils, i.e., a mineral oil (Brightstock 150), a synthetic Polyalphaolefin (Spectrasyn 40) and castor oil (85 to 90 wt.% ricinoleic acid triglyceride). Small- and wide-angle X-ray scattering measurements indicate a strong interaction of the polyester with castor oil and an increase in the crystalline fraction, with an increasing polymer amount from 5 to 40 wt.%. Moreover, infrared analysis of the polyester in castor oil showed gel formation at a minimum concentration of 20 wt.%. The strong interaction of the polyester with castor oil compared to the other two base oils led to an increase in the yield point γF as a measure of the mechanical stability of the gel, which was determined to be 5.9% compared to 0.8% and 1.0% in Brightstock and Spectrasyn, respectively.

Influence of Silicon Additives on Tribological and Rheological Test Results for Vegetable Lubricants.

This paper describes an investigation of the effects of silicone-containing additives on the tribological and rheological properties of various lubricant blends. Aerosil® and layered silicate were used to modify lubricants containing rapeseed, linseed and soy oil that were thickened with soap thickener. Tribological tests were carried out using a four-ball concentric contact tester. On the basis of the data obtained from the tribological studies of the selected lubricant blends, it was concluded that the addition of amorphous silica increased the anti-seizure and anti-wear properties of the tested lubricants. The addition of montmorillonite caused a significant increase in the values of the individual parameters determining the level of lubricating properties of the tested lubricants in comparison with the lubricants modified with the silica additive. Based on the results of the rheological tests of the studied lubricants, it was found that the applied additives caused a change in the dynamic viscosity and chemical structure of the tested lubricants, expressed by a change in the values of the G' and G″ indices. The main finding of this manuscript was to demonstrate that the use of montmorillonite and aerosil additives improves the functional properties of vegetable-based plastic lubricants. The performance of tribological and rheological tests is of great scientific importance, as it provides an insight into the interaction of siliceous additives with the results of tribological tests on vegetable-oil-based greases. These findings make it possible to determine the behaviour of the lubricant under load and add to the knowledge of vegetable greases.

Cold Drawing of AISI 321 Stainless Steel Thin-Walled Seamless Tubes on a Floating Plug.

The paper presents the results of an analysis of the process of drawing AISI 321 stainless steel thin-walled seamless tubes on a floating plug. The influence of the geometry of dies and plugs, drawing velocity, and lubricants on the possibility of carrying out the pipe drawing process without a loss of strength of the lubricating film and, consequently, disturbance of the forming process and tube cracking, and also on the temperature in the drawing process, the mechanical properties of the tubes drawn, and the microhardness and roughness of the inner and outer surface of the tubes was investigated. The parameters of the drawing tools used were as follows: angle of drawing dies α = 16° and floating plugs with angles of inclination of the conical part of the plug ß = 11.5°, 13°, and 14°. The drawing dies and floating plugs were made of G10 sintered carbide. Drawing speed was varied over the range 1 to 10 m/min. The study used several lubricants. Tubes with dimensions (outer diameter D0, wall thickness g0 before drawing process) D0 = 19 mm, g0 = 1.2 mm and D0 = 18 mm, g0 = 1.2 mm were drawn to produce tubes with dimensions (outer diameter Dk, wall thickness gk after drawing process) Dk = 16 mm, gk = 1.06 mm on a drawbench with the same total elongation, while the diameter and wall thickness were changed. During the process, continuous measurements were made of the drawing force and temperature in the deformation zone and on the tube surface. It was found that the drawing process causes a decrease in the roughness parameters Ra and Rz of the inner surface of the tubes. Moreover, after drawing, an increase of 30-70% was observed in the microhardness of the tube material in relation to the microhardness of the charge material. Based on the test results, it can be concluded that the work of frictional forces is the main direction of optimization of tube drawing on a floating plug process of hard-deforming materials.

Graphene Enhances the Loading Capacity and Lubrication Performance of Ionic Liquids: A Molecular Dynamics Study.

Ionic liquid (IL) combined with graphene additives have garnered extensive attention in the field of high-performance lubricating materials. However, the ambiguous mechanism of graphene influencing the load-carrying and anti-wear capacity of ILs needs further study. In this work, friction simulation shows that adding graphene causes friction coefficient to reduce by up to 88% compared with pure ILs, but lubrication performance is lost due to the destruction of graphene under high stress. Meanwhile, multilayer graphene has better friction-reducing performance and friction durability as compared to the monolayer structure, which is attributed to the easy-shear property and the reduction in the percentage of high tensile stress sites in multilayer graphene structure. In addition, it was found that excessively thick ILs film would form a three-body abrasive wear structure with graphene, which accelerated the structural destruction of graphene and caused a decline in its tribological properties. It is believed these findings can be valuable for designing of high-performance lubricating oil for practical engineering.

Therapeutic Choices for Genitourinary Syndrome of Menopause (GSM) in Breast Cancer Survivors: A Systematic Review and Update.

(1) Background: Genitourinary syndrome of menopause (GSM) is a medical condition that can affect breast cancer survivors (BCS). This is a complication that often can occur as a result of breast cancer treatment, causing symptoms such as vaginal dryness, itching, burning, dyspareunia, dysuria, pain, discomfort, and impairment of sexual function. BCS who experience these symptoms negatively impact multiple aspects of their quality of life to the point that some of them fail to complete adjuvant hormonal treatment; (2) Methods: In this systematic review of the literature, we have analyzed possible pharmacological and non-pharmacological treatments for GSM in BCS. We reviewed systemic hormone therapy, local hormone treatment with estrogens and androgens, the use of vaginal moisturizers and lubricants, ospemifene, and physical therapies such as radiofrequency, electroporation, and vaginal laser; (3) Results: The data available to date demonstrate that the aforementioned treatments are effective for the therapy of GSM and, in particular, vulvovaginal atrophy in BCS. Where possible, combination therapy often appears more useful than using a single line of treatment; (4) Conclusions: We analyzed the efficacy and safety data of each of these options for the treatment of GSM in BCS, emphasizing how often larger clinical trials with longer follow-ups are needed.

Simultaneous effects of MWCNT and SiO2 on the rheological behavior of cooling oil and sensitivity analysis.

Many scholars are attracted to nano-lubricants due to their unique properties. In the present study, the rheological behavior of a new generation of lubricants has been investigated. SiO2 nanoparticles with an average diameter of 20-30 nm along with MWCNT with an internal diameter of 3-5 nm and the external diameter of 5-15 nm has been dispersed in 10W40 engine oil as base-lubricant and MWCNTs-SiO2 (20%-80%)/10W40 hybrid nano-lubricant has been produced. Nano-lubricant behavior agrees with the Herschel-Bulkley model and is of Bingham pseudo-plastic type below 55 ° C . Also, in the temperature of 55 ° C , nano-lubricant behavior has changed to Bingham dilatant. The viscosity is increased by 32% in the proposed nano-lubricant compared to base lubricant (Dynamics Viscosity Enhancement). Finally, a new correlation with a precision index of R-squared >0.9800, Adj. R-squared >0.9800, and the maximum margin of deviation of 2.72% has been presented, increasing the applicability of this nano-lubricant. Eventually, the sensitivity analysis of nano-lubricant has been conducted, studying the comparative effect of volume fraction and temperature on viscosity.

A randomized trial on the effectiveness and safety of 5 water-based personal lubricants.

BACKGROUND: A range of personal lubricants with different formulations and subsequent properties are available for relief of discomfort associated with vaginal dryness; however, there are limited clinical data to support the efficacy and safety of many commercially available lubricants. AIM: To determine the effectiveness and safety of 5 water-based personal lubricants for the relief of intimate discomfort associated with vaginal dryness in pre- and postmenopausal women: 4 that were formulated to meet the World Health Organization (WHO) guidelines for osmolality and pH and 1 preexisting lubricant of higher osmolality and pH. METHODS: An open-label, parallel-design study was performed in women aged 18 to 65 years with mild-to-moderate vaginal dryness and dyspareunia. Participants were randomized to 1 of 5 lubricants (A-E) from 3 brands (Durex, KY, Queen V). They were instructed to use their allocated lubricants during vaginal intercourse at least once a week over a 4-week period. The Female Sexual Function Index (FSFI) measured sexual functioning after 4 weeks of use as an indicator of lubricant performance. OUTCOMES: The primary outcome was change from baseline in total FSFI score after 4 weeks of product use. RESULTS: A total of 174 women completed the study. The primary end point-a prespecified increase in FSFI ≥4 points from baseline after 4 weeks of use-was met by all 5 lubricants tested. A statistically significant improvement was observed across all 6 domains of the FSFI from baseline to 4 weeks of use with all 5 lubricants (P < .0001 for lubrication and pain reduction and P < .05 for all other domains). No serious adverse events occurred in the study, and the tolerance of all 5 lubricants was good/very good. CLINICAL IMPLICATIONS: The efficacy and safety of the tested lubricants are not compromised when formulated to meet the WHO criterion of osmolality ≤1200 mOsm/kg. The lubricants tested in this investigation can be used not only to relieve symptomatology of vaginal dryness and dyspareunia but also to enhance overall sexual satisfaction. STRENGTHS AND LIMITATIONS: This study provides clinical evidence for the efficacy and safety of 5 lubricants, including those formulated to meet WHO guidelines, in relieving symptoms of vaginal dryness and improving the overall sexual experience. The open-label design may have introduced bias into the study. CONCLUSION: All 5 lubricants, including those formulated to be compliant with guidelines on pH and osmolality, can be considered effective and well tolerated for the relief of discomfort associated with vaginal dryness.

Combined nuclear magnetic resonance methods in quality control of lubricants in green energy production.

NMR methods were applied for lubricant analysis. Different factors influence the real aging of lubricants on diverse length scales and are captured by NMR. Chemical conversion of additives is addressed by NMR spectroscopy. High-field NMR experiments allow the identification and quantification of chemical components and are transferred to benchtop devices. Molecular dynamics and contaminations like fuel or abrasion are addressed via NMR relaxation and diffusion. Quality parameters were extracted via suitable data analysis of NMR raw data, which allow the detection of aging and indicate changes in the oil composition. At the same time, the methodology is optimized to the conditions in quality control. The feasibility is shown the example of a series of lubricants from applications in regenerative energy production, namely, wind turbine oils and biogas motor oils.