Evaluation of metal ions and DNA recovery from the surface of fired and unfired brass ammunition to improve STR profiling.

Interest in recovering DNA from the surface of ammunition evidence for genotyping has increased over the past few years. Numerous studies have examined a variety of methods to maximize DNA recovery from these types of challenging samples, but successful DNA profiling has been inconsistent. Low amounts of DNA and PCR inhibition due to metal ions have been suggested as the leading causes of poor results; however, no study quantitatively examined the presence of metal ions at various stages of the DNA analysis workflow from DNA collection through to amplification. In this study, the effectiveness of six different DNA collection and purification methods commonly used by forensic laboratories to process brass ammunition for DNA evidence was investigated. The amount of copper, zinc, and other metals co-recovered from fired and unfired brass casings during DNA collection (using numerous soaking, swabbing, and direct PCR protocols) was quantified via Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES). This same panel of metals was subsequently quantified after DNA lysis and purification steps. Results demonstrated that low amounts of DNA, DNA damage, and degradation are more detrimental to STR typing results than PCR inhibition, as metal ions were successfully removed by all DNA purification methods tested. Furthermore, the use of metal ion chelators increased the amount of DNA recovered and number of reportable STR alleles. This research informs the forensic community on the most effective way to collect and process trace amounts of biological material from brass ammunition and similar evidence.

Evaluation of the effects of wiping decontamination for filter cartridges of elastomeric half-mask respirators (EHMRs).

BACKGROUND: A major concern among health care experts is a shortage of N95 filtering facepiece respirators during a pandemic. If the supply of N95 filtering facepiece respirators becomes limited, reusable elastomeric half-mask respirators (EHMRs) may be used to protect health care workers. The focus of this study was to evaluate the effects on the filter performance of wiping decontamination for EHMR P100 filter cartridges. METHODS: The filter cartridge exterior of EHMR Honeywell, Moldex, and Mine Safety Appliance (MSA) models was wiped using quaternary ammonium and sodium hypochlorite wipes. These filter cartridge properties were assessed including observational analysis and filter performance tests. These wiping and assessing procedures were repeated after each set of wiping cycles (50, 100, 150, 200, and 400 cycles) to determine the effects of wiping decontamination. RESULTS: For sodium hypochlorite wipes, Honeywell, Moldex, and MSA models passed the National Institute for Occupational Safety and Health (NIOSH) liquid particulate penetration criteria for all wiping cycles from 50 to 400 (penetrations<0.014%). For quaternary ammonium wipes, filter penetrations of Moldex failed (penetrations>0.03%) after 150 cycles, while the filter penetrations of Honeywell and MSA passed for all wiping cycles (penetrations ≤0.013%). CONCLUSIONS: Wiping decontamination methods using sodium hypochlorite and quaternary ammonium wipes could be considered promising decontamination candidates for Honeywell, Moldex, and MSA reuse, except for the wiping number selection for Moldex (<150 cycles) when using the quaternary ammonium wipe.

Two-dimensional printing of nanoparticles as a promising therapeutic method for personalized drug administration.

The necessity for personalized patient treatment has drastically increased since the contribution of genes to the differences in physiological and metabolic state of individuals have been exposed. Different approaches have been considered so far in order to satisfy all of the diversities in patient needs, yet none of them have been fully implemented thus far. In this framework, various types of 2D printing technologies have been identified to offer some potential solutions for personalized medication, which development is increasing rapidly. Accurate drug-on-demand deposition, the possibility of consuming multiple drug substances in one product and adjusting individual drug concentration are just some of the few benefits over existing bulk pharmaceuticals manufacture, which printing technologies brings. With inclusion of nanotechnology by printing nanoparticles from its dispersions some further opportunities such as controlled and stimuli-responsive drug release or targeted and dose depending on drug delivery were highlighted. Yet, there are still some challenges to be solved before such products can reach the pharmaceutical market. In those terms mostly chemical, physical as well as microbiological stability concerns should be answered, with which 2D printing technology could meet the treatment needs of every individual and fulfill some existing drawbacks of large-scale batch production of pharmaceuticals we possess today.

An examination of quitting smoking as a reason for vaping by the type of nicotine vaping device used most often among adults who smoke and vape: Findings from the Canada, England and the United States 2020 ITC Smoking and Vaping Survey.

Several nicotine vaping product (NVP) device types are available to consumers, and many people who smoke report vaping to help them quit. This study included data from the Wave 3 (2020) ITC Smoking and Vaping Survey in the US, Canada, and England and included 2324 adults who were smoking cigarettes and vaping at least weekly. Device types currently used most often (disposables, cartridges/pods, or tank systems) were assessed using weighted descriptive statistics. Multivariable regression analyses were used to compare differences between respondents who reported vaping to quit smoking ('yes' vs. 'no/don't know') by device type, overall and by country. Overall, 71.3% of respondents reported vaping to help them quit smoking, with no country differences (p = 0.12). Those using tanks (78.7%, p < 0.001) and cartridges/pods (69.5%, p = 0.02) were more likely to report this reason for vaping than those using disposables (59.3%); respondents using tanks were also more likely than those using cartridges/pods (p = 0.001) to report this reason. By country, respondents in England using cartridges/pods or tanks (vs. disposables) were more likely to report vaping to quit smoking (with no difference between cartridges/pods and tanks). In Canada, respondents using tanks were more likely to report vaping to quit smoking than those using cartridges/pods or disposables (no difference between disposables and cartridges/pods). No significant differences by device type were found in the US. In conclusion, most adult respondents who smoked and vaped reported using either cartridges/pods or tanks, which were associated with greater odds of vaping for the purpose of quitting smoking versus disposables, with some country variations.

Lead isotope measurement of primer gunshot residues and likelihood ratio predictions for forensic cartridge discrimination and individualization in China.

Gunshot residues (GSR), cartridge projectiles, and casings are frequently encountered evidence in gun-related forensic investigations. However, in circumstances where the investigation of striation marks is impossible, such as unrecovered or deformed projectiles and cartridge casings, GSR deposited on the hands or clothes of the shooter and victim-related items can provide information to establish a link between the suspect, the firearms used, and the victim. Since the formula of primers used by all cartridge manufacturers in China is identical, links based on the conventional morphological and compositional analysis of GSR are difficult to establish. However, the abundance of lead isotopes in primer components of lead styphnate varies significantly, and a fundamental understanding of these differences may facilitate the validation of primer (p)GSR evidence in forensic investigations. Here, 44 pGSR samples were characterized by Pb isotope ratios of 206 Pb/204 Pb, 207 Pb/204 Pb, and 208 Pb/204 Pb using laser ablation multicollector inductively coupled plasma mass spectrometry. There was no obvious mass fractionation of the lead isotope ratios of the primers from individual cartridges analyzed before and after the shooting process, thereby establishing a basis for the comparison of pGSR and unfired cartridges. Evaluation of the results using univariate likelihood ratio (LR) computations revealed low rates of misleading evidence (<0.53%) The results demonstrated that lead isotope ratio analysis of pGSR and LR predictions can provide a practicable method for forensic cartridge discrimination and individualization.

Development and Qualification of Visible Particle Load Analysis Methods for Injectable Drug Product Primary Packaging Components.

In the biopharmaceutical industry, the observation of a single particle in a vial or syringe may result in entire lots of drug product recalls. U.S. Pharmacopeia <787> and <788> describe light obscuration methods and particle collection (membrane filtration) followed by light microscopy for particle counting of filled drug products. However, there are no corresponding pharmacopeial methods for determining the particle levels of unfilled primary packaging components or their packaging materials (tubs, nests, bags, etc.). This article describes a quantification method to accurately assess the number of particles in primary containers and corresponding closures. As a microscopic method, the size ranges can be set by the user and are limited only by the optical properties of the microscope and analysis time. Particle load is a critical quality attribute that has a direct impact on product safety. Applying a standardized method to compare the effect of process changes on particle load can aid manufacturers in refining their processes to minimize particulates. Described herein are the critical parameters to develop physical rinse methods and the subsequent qualification results to measure the visible particle load of nonsiliconized and siliconized primary packaging systems.

Optimization of a Multi-Residue Analytical Method during Determination of Pesticides in Meat Products by GC-MS/MS.

In this study, a multi-residue analysis was developed for 32 compounds, including pesticides and metabolites, in five meat products using gas chromatography-tandem mass spectrometry (GC-MS/MS). The validation of the developed analytical method was also evaluated in accordance with Codex Alimentarius guidelines. Aminopropyl (NH2), C18, and florisil solid phase extraction (SPE) cartridges were used to evaluate and optimize the cleanup procedure of the tested samples prior to GC-MS/MS analysis. Based on the analytical performance, the C18 SPE cartridge was deemed to be the most suitable among the examined SPE cartridges. The optimized method demonstrated that 29 out of 32 tested compounds acquired good linearity (R2 ≥ 0.99), and 25 tested compounds displayed the method limit of quantification (MLOQ) ≤ 0.01 mg/kg. Out of the 32 tested compounds, only 21 compounds met the acceptable analytical criteria for the lard and tallow samples, compared to 27 compounds in the beef, pork, and chicken samples that falls within the acceptable standards for recovery (70-120%) and analytical precision (relative standard deviation RSD ≤ 20%). The average matrix effect was widely varied (20.1-64.8%) in the studied meat samples that were affected by either ion enhancement or suppression. In particular, in the lard sample, 13 compounds showed poor recovery and analytical precision due to ion suppression. Thus, the matrix effect (ME) was considered a critical factor during multi-residue pesticide analysis in different meat products. In conclusion, this developed analytical method can be used as a routine monitoring system for residual pesticide analysis in livestock products with acceptable analytical standards. Further meticulous analytical studies should be optimized and validated for multi-residue pesticide analysis in diversified meat products.

Development of a reliable UHPLC-MS/MS method for simultaneous determination of zearalenone and zearalenone-14-glucoside in various feed products.

A reliable ultra-high-performance liquid chromatography-tandem mass spectrometry method (UHPLC-MS/MS) was developed for the simultaneous determination of two mycotoxins, that is, zearalenone (ZEN) and zearalenone-14-glucoside (ZEN-14G) in formula feed, concentrated feed, and premixed feed products. An improved sample pretreatment was achieved with the hydrophilic-lipophilic balance (HLB) cartridges efficiently removing the impurities and enriching the target analytes in different feeds. The critical parameters affecting the performance of the solid-phase extraction (SPE) procedure were carefully optimized, and 20% acetonitrile in water as the loading solution, 50% methanol in water as the washing solvent, and 5 ml of methanol as the elution solvent yielded the optimal purification efficiencies. The established method was thoroughly validated in terms of linearity (R 2 ≥ 0.999), sensitivity (limit of quantification in the range of 0.50-5.00 µg kg-1), recovery (89.35 ± 2.67% to 110.93 ± 1.56%), and precision (RSD, 3.00-14.20%), and it was then successfully applied to investigate a total of 60 feed samples. Among them, 50 samples were found to be contaminated with ZEN (an incidence of 83.3%) at levels ranging from 0.63 to 615.24 µg kg-1, whereas 22 samples were contaminated with ZEN-14G (an incidence of 36.7%) in the range of 0.89-15.31 µg kg-1. The developed method proved to be a specific and reliable tool for intensive monitoring of ZEN and ZEN-14G in complex feed matrices.

E-cigarette vaping associated acute lung injury (EVALI): state of science and future research needs.

"E-Cigarette (e-cig) Vaping-Associated Acute Lung Injury" (EVALI) has been linked to vitamin-E-acetate (VEA) and Δ-9-tetrahydrocannabinol (THC), due to their presence in patients' e-cigs and biological samples. Lacking standardized methodologies for patients' data collection and comprehensive physicochemical/toxicological studies using real-world-vapor exposures, very little data are available, thus the underlying pathophysiological mechanism of EVALI is still unknown. This review aims to provide a comprehensive and critical appraisal of existing literature on clinical/epidemiological features and physicochemical-toxicological characterization of vaping emissions associated with EVALI. The literature review of 161 medical case reports revealed that the predominant demographic pattern was healthy white male, adolescent, or young adult, vaping illicit/informal THC-containing e-cigs. The main histopathologic pattern consisted of diffuse alveolar damage with bilateral ground-glass-opacities at chest radiograph/CT, and increased number of macrophages or neutrophils and foamy-macrophages in the bronchoalveolar lavage. The chemical analysis of THC/VEA e-cig vapors showed a chemical difference between THC/VEA and the single THC or VEA. The chemical characterization of vapors from counterfeit THC-based e-cigs or in-house-prepared e-liquids using either cannabidiol (CBD), VEA, or medium-chain triglycerides (MCT), identified many toxicants, such as carbonyls, volatile organic compounds, terpenes, silicon compounds, hydrocarbons, heavy metals, pesticides and various industrial/manufacturing/automotive-related chemicals. There is very scarce published toxicological data on emissions from THC/VEA e-liquids. However, CBD, MCT, and VEA emissions exert varying degrees of cytotoxicity, inflammation, and lung damage, depending on puffing topography and cell line. Major knowledge gaps were identified, including the need for more systematic-standardized epidemiological surveys, comprehensive physicochemical characterization of real-world e-cig emissions, and mechanistic studies linking emission properties to specific toxicological outcomes.

Filtration performance and breathing resistance of elastomeric half mask respirator P100 filter cartridges after repeated and extended use in healthcare settings.

In 2020, the Centers for Disease Control and Prevention recommended the use of the National Institute for Occupational Safety and Health-certified Elastomeric Half Mask Respirators equipped with N95 or P100 respirator filter cartridges for protection against the SARS-CoV-2 viral agent, as a viable alternative to N95 filtering facepiece respirators. Additionally, the Centers for Disease Control and Prevention recommendations stated that based on current practice, it was acceptable to repeatedly use these filter cartridges for up to 12 months as a contingency capacity strategy during anticipated respirator shortages. To validate this recommendation, an investigation was undertaken in which Elastomeric Half Mask Respirators equipped with P100 respirator filter cartridges were deployed and used by healthcare professionals in clinical settings (i.e., inpatient nursing units, operating rooms) for extended periods. These filter cartridges were subsequently tested to accurately quantify their filtration efficiency and breathing resistance to determine if they continued to meet National Institute for Occupational Safety and Health's performance requirements. Findings from this investigation confirmed that an Elastomeric Half Mask Respirator when equipped with a P100 filter cartridge continues to provide a high level of aerosol filtration performance (≥99.97%) and exhibits little change in breathing resistance even after 12 months of repeated use (i.e., wear, cleaning, and disinfection between patient use and at the end of work shift) in healthcare settings.

Auxiliary Utensils in Cosmetic and Medical Tattoo Settings.

Cosmetic and medical tattooing is miniaturized tattooing of high precision and thus requires many dedicated utensils including advanced devices for marking and anatomical delineation. Symmetry is a special demand, as is aesthetic outcome, building on perfectionated detail. The artist shall master design and strategy along with advanced technical performance helped by having and using the right tools. This article reviews and illustrates the many special utensils involved in good-practice cosmetic and medical tattooing, exemplified by selected tools used for cleansing, disinfection, pre-operative measurement and marking, and special tattoo machines, cartridges, microblades and needles. Personal protective equipment used to prevent infections among technicians and customers are also illustrated. Educational tools, such as face phantoms and eyebrow mats, are displayed. Mastering cosmetic and medical tattooing is a challenge and involves mastering the many auxiliaries along with needle configurations, machines, inks and the whole setting of the activity. This review is an illustrated practical record and a guideline to good professional practice.

Streptococcal Toxic Shock Syndrome: A Case Report.

Streptococcal toxic shock syndrome is a serious complication of group A Streptococcus infection with a high mortality rate. Rapid detection, early intensive care support, and surgical management are paramount in treating these patients. We present a case of a 65-year-old male, with a documented medical history of hypertension, type 2 diabetes mellitus, and peripheral arterial disease. The patient was evaluated in the emergency department with a chief complaint of pain, swelling in his left leg, and fever. Physical examination showed tachycardia, hypotension, and clear inflammatory signs in the left leg. After initial clinical and laboratory evaluation, the patient was admitted with a diagnosis of cellulitis and urinary tract infection. He presented progressive worsening with multi-organ dysfunction, requiring vasopressor support, invasive mechanical ventilation, and renal replacement therapy. Streptococcus pyogenes was isolated in blood cultures, and a streptococcal toxic shock syndrome was considered. Appropriate antibiotic therapy, immunoglobulins, hemoperfusion, and corticosteroid therapy were administered, with clinical improvement. During hospitalization, there was a progressive improvement in the skin lesion. Once clinically stabilized the patient was discharged with follow-up. The case presented shows the rapid evolution of cutaneous streptococcal infection with multiorgan dysfunction. Although these types of infections have an associated high mortality rate, this patient survived. The use of immunoglobulin and hemoperfusion technique, in this case, might have contributed to this positive outcome. Therefore, we highlight the need for high suspicion of this syndrome, especially in diabetic patients presenting with skin lesions. Once the diagnosis is established, these infections require close surveillance and rapid and intensive treatment.

Antibacterial and antioxidant potential of the phenolic extract and its fractions isolated from Allium ascalonicum (onion) peel.

Aqueous methanolic (20:80) crude extract of the outer peel of Allium ascalonicum (onions) was fractionated into anthocyanin (II), acidic (i.e., phenolic acids, Ia), neutral A (i.e., flavanols, Ib) and neutral B (i.e., flavonols, Ic) phenols using C-18 and hydrophilic-lipophilic balanced (HLB) Co-polymer cartridges. The fractions were analysed for total phenolic, total flavonoids, antibacterial activity, antioxidant potential and lipoxygenase (LOX) inhibition. The recovery of total phenols and bio functional activity in all fractions were found to be more in HLB. All fractions showed antimicrobial activity against tested strains with phenolic acids (Ia) being most active and flavanol (Ib) least active, while the highest free radical scavenging, reducing power and LOX inhibition was exhibited by flavonol (Ic) and least by flavanols (Ib). HPLC analysis revealed the presence of vanillic acid and quercetin in non-anthocyanin I and cyanidin in anthocyanin II.

The effect of Sr resin cartridge age on stable Sr recovery methods used in Sr-90 analysis.

Radioactive strontium is a nuclear fission decay product found in industrial products and nuclear waste and is released during nuclear accidents. Current urine radiostrontium separation methods often are based on the use of Sr resin columns or cartridges (Eichrom Technologies). Most of these analytical methods use stable Sr as a tracer, with subsequent Sr recovery. The gravimetric recovery method requires 120 times more stable Sr than does the inductively coupled plasma mass spectrometry method described here. This difference can affect cartridge performance especially with aging cartridges.

Qualitative fitting characteristics of elastomeric half face-piece respirators using Isoamyl acetate agent.

To examine the fit testing of elastomeric half face-piece respirators (EHRs), a total of 41 candidates were randomly assigned into seven EHRs equipped with organic vapor (OV) cartridges which were commonly used in the Iranian industrial workplaces. The qualitative fitting into the facial dimensions was assessed using the Allegro Isoamyl Acetate fit test kit. While the studied EHRs showed very low passing fit testing rates, the 3M, AoSafety (Medium), and AoSafety (Large) had the highest passing rates with 22.0%, 14.60%, and 9.76%, respectively. The AoSafety (All sizes) delivered a higher passing fit test rate than the 3M brand (29.30 vs. 22.0%). The one size fits all respirators including the DUO and Climax showed lower proportions of passing fit tests compared with AoSafety three-size system brands (2.40% and 4.90% vs. 29.30%). Low fit test passing rates were determined among different respirators. The respirators with various sizes and styles had more opportunities for different wearers to pass the fit test than single size models. The initial and annual fit testing requirements shall be developed by local government. Also, the manufacturers are required to pay attention to respirator features and subject characteristics during the production to obtain satisfactory protection for the end-users.

Method validation, persistence, and safety evaluation of 2,4-D in tea (Camellia sinensis) by LC-MS/MS.

An analytical method was developed by using LC-ESI(-ve)-MS/MS to investigate the residue dynamics of 2,4-D (2,4-dichlorophenoxyacetic acid) in green tea leaves, processed tea, tea liquor, and tea-cropped soil at Singhiajhora Tea Estate and Putinbari Tea Estate at Terai Region, Darjeeling District, West Bengal, India. In this method, an acidified methanol was used for extraction and subsequent clean-up was done by HLB (hydrophilic lipophilic balanced) cartridges. The method was validated as per SANTE guideline (SANTE/11813/2017). The limit of quantification (LOQ) of 2,4-D was 0.05 mgkg-1 and average % recoveries were in the range from 88.05 to 113.28 with relative standard deviation (RSD) 3.46 to 6.43. The dissipation of 2,4-D followed the 1st-order reaction kinetics with a half-life (T1/2) of 1.51-1.61 day at the recommended dose and 2.50-2.72 day for doubled recommended dose in tea for both locations. This method can be applied successfully for the determination of 2,4 D residues in/on tea matrix and subsequent studies on safety evaluation showed that the use of 2,4-D in tea is safe.

Non-Destructive Characterization of Industrial Membrane Cartridges by Using Liquid-Liquid Displacement Porosimetry (LLDP).

This works aims to propose and demonstrate the accuracy of a novel method of characterization aimed for non-destructive analysis of microfiltration (MF) membrane cartridges. The method adapts conventional liquid-liquid displacement porosimetry (LLDP) for performing an in-line porosimetric analysis of the membrane cartridges, getting their pore size distributions (PSDs) and mean pore diameters (davg). Six commercial filtration cartridges featuring polyethersulfone (PES) pleated membranes were analyzed using a newly designed filtration rig, based on the liquid-liquid displacement porometer, developed at the Institut de la Filtration et des Techniques Séparatives (IFTS) and operated at constant flow. The experimental rig allows the direct and non-destructive characterization of the cartridge in its original presentation. Results have been compared with those obtained by using gas-liquid displacement porosimetry (GLDP) on small membrane coupons detached from such cartridges. The comparison allows us to conclude that the proposed method gives enough accuracy in the determination of porosimetric characteristics of the filters. This method can be used as a precise characterization technique for a non-destructive in-line study of filter performance and can be envisaged as useful to periodic quality or fouling control of the commercial cartridges.

[Morphological specific damage of clothing by shots from a smooth-bore hunting rifle with cartridges of multi shells from various distances]. / Morfologicheskie osobennosti povrezhdenii odezhdy, prichinennykh vystrelami s razlichnykh rasstoyanii iz gladkostvol'nogo okhotnich'ego ruzh'ya patronami s polisnaryadami.

The aim of the work is to study the design features of cartridges with multi shells for a smooth-bore hunting rifle of 12 mm caliber and results of firing these cartridges from various distances. Were revealed the morphological signs and features of injuries to tissue targets hit from a distance of 5-40 m. Was argued a necessity to continue a comprehensive study of the issue with the subsequent development of criteria for differential diagnosis of this type of shot injuries.

Sample Preparation to Determine Pharmaceutical and Personal Care Products in an All-Water Matrix: Solid Phase Extraction.

Pharmaceuticals and personal care products (PPCPs) are abundantly used by people, and some of them are excreted unaltered or as metabolites through urine, with the sewage being the most important source to their release to the environment. These compounds are in almost all types of water (wastewater, surface water, groundwater, etc.) at concentrations ranging from ng/L to µg/L. The isolation and concentration of the PPCPs from water achieves the appropriate sensitivity. This step is mostly based on solid-phase extraction (SPE) but also includes other approaches (dispersive liquid-liquid microextraction (DLLME), buckypaper, SPE using multicartridges, etc.). In this review article, we aim to discuss the procedures employed to extract PPCPs from any type of water sample prior to their determination via an instrumental analytical technique. Furthermore, we put forward not only the merits of the different methods available but also a number of inconsistencies, divergences, weaknesses and disadvantages of the procedures found in literature, as well as the systems proposed to overcome them and to improve the methodology. Environmental applications of the developed techniques are also discussed. The pressing need for new analytical innovations, emerging trends and future prospects was also considered.

Further Examination of the Performance of Blank Cartridges Used in Captive Bolt Devices for the Pre-Slaughter Stunning of Animals.

Blank cartridges produce gas through deflagration and are used as the main power source in captive bolt devices used within abattoirs and on farms in Europe. The European legislation recognises this and requires users to follow manufacturers' recommendations in terms of which power cartridge to use. Variation in cartridge performance of Eley (E) cartridges was found in previous research, which was published before Accles and Shelvoke (AS) started full production of their own cartridges. This work examined cartridge performance, structural integrity and dimensional tolerances, and found that the new AS cartridges that varied more greatly in performance in terms of velocity, kinetic energy and mechanical stability of casing than the more established E cartridges. In this study, 15% of the cartridges split at the primer flange on firing, resulting in less kinetic energy, which could impact the ability of the captive bolt to produce a successful stun. This, combined with the variation in performance in a primary component of a device that should have a uniform performance, could lead to animal welfare issues as this variation cannot be predetermined by examination of the cartridge pre firing.