Investigating the availability of 3D-printed firearm designs on the clear web

The release of the plans of the 3D-printed Liberator firearm sparked a wave of new designs from creators worldwide, resulting in an extensive collection of 3D-printed firearm plans, in particular blueprints, and parts available for almost unrestricted download on the internet. Identifying and categorizing the diverse range of 3D-printed firearms and components pose a challenge due to the abundance of designs available. Between 2021 and April 2023, data was collected on over 2,100 3D-printed firearm plans. While blueprints of fully 3D-printed firearms initially dominated the scene, hybrid designs and parts kit completions / conversions (PKC) have gained popularity for their improved reliability and performance. The now highly networked community offers considerable support with detailed instructions and procedures, providing precise guidance for construction. This systematic classification, grouping and structuration of the recorded data on the Clear Web supported the identification of patterns of the main threat trends related to 3D-printed firearms.

Was a 3D-printed firearm discharged? Study of traces produced by the use of six fully 3D-printed firearms

Since the blueprints of the Liberator were published and successfully tested, countless new designs for said 3D-printed firearms and 3D-printed firearm components have been created and made publicly available. These new 3D-printed firearms, which are praised by their designers as ever more reliable, can be found on the Internet with little effort. Press reports have shown that various models of 3D-printed firearms have already been confiscated by law enforcement services around the world. So far, forensic studies have addressed this set of problems relatively little, whereby for the most part only the Liberator has been examined in detail and three other designs were only included a few times. The rapid pace of this development poses new challenges for forensic investigations and unveil new spheres of investigation regarding 3D-printed firearms. This research initiative aims to determine whether the results from previous studies on Liberators, are also reproducible and observable when using other models of 3D-printed firearms. In this respect six fully 3D-printed firearms - PM422 Songbird, PM522 Washbear, TREVOR, TESSA, Marvel Revolver and Grizzly - were produced on a material extrusion type Prusa i3 MK3S using PLA as the material. Test firings of these 3D-printed firearms have shown that they are indeed functional, but that, depending on the model, they suffer different levels of damage when fired. However, they were all rendered inoperative after one discharge and could not be used for further discharges unless the broken pieces were replaced. As in other studies, the firing process and the resulting ruptures on the 3D-printed firearm, projected polymer parts and fragments of different sizes and in different quantities into the immediate environment. The parts could be physically matched, allowing the reconstruction and identification of the 3D-printed firearms. Elements of ammunition also showed traces of melted polymer on the surface and cartridge cases bore tears or swellings.

Survival of Patients with Cystic Fibrosis Depending on Mutation Type and Nutritional Status

The purpose of the study was to evaluate the influence of nutrition and of the severity of mutation type on survival rate in cystic fibrosis (CF) patients. Data were longitudinally collected from 60 hospitalized adult CF patients, aged 18-50. The variables consisted of body mass index (BMI) ratio, Cole's BMI cut-off points, severity of mutation type, and survival rate of CF patients. We found that the mean BMI was strongly associated with the severity of mutation type and was significantly lower in patients with severe mutations of grade I and II. The mutation type significantly affected the patients' survival rate; survival was greater in patients with mild and undefined mutation types. The BMI and Cole's cut-off points also had a significant influence on survival rate. CF patients, who suffered from malnutrition and emaciation, had a shorter survival rate than those with proper nutritional status. In conclusion, the study findings confirmed a significant effect of nutritional status and of mutation type on survival rate of CF patients.

Interaction between dendrimers and regulatory proteins. Comparison of effects of carbosilane and carbosilane–viologen–phosphorus dendrimers

For nanoparticles to be used successfully in biomedical application, their interactions with biological fluids need to be investigated, in which they will react with proteins and other macromolecules.

Biological status of adult patients with cystic fibrosis

Cystic fibrosis (CF) is the most common autosomal disorder in the Caucasian population. The main goal of the study was to assess the biological condition of adult patients with CS. Data of 90 CF patients aged 18-31 were considered. The biological condition was determined by the measurement of somatometric traits and the nutritional status. The results show a considerable physical retardation and a poor nutritional status of the studied patients. Nearly 45% of the patients showed symptoms of malnutrition, ranging from slight undernutrition to emaciation. The results, however, show a considerable variability of data among the CF patients compared with the healthy population. A significant relationship between the type of mutation and nutritional status was demonstrated.

Body mass index, waist to hip ratio and waist/height in adult Polish women in relation to their education, place of residence, smoking and alcohol consumption

Obesity is a complex, multifactorial disorder that develops from genotype and environmental interactions. The aim of this study is to describe the variability of body mass index (BMI), waist to hip ratio (WHR) and waist to height (W/Ht) in adult Polish women, and to determine relationships between these variables and factors such as education, place of residence, smoking and alcohol drinking. The tested group consisted of 10,254 women aged 25-95 years, who voluntarily filled in questionnaires and participated in anthropometric measurements (body height and mass, waist and hip circumferences). The BMI, WHR and W/Ht values were calculated based on these measurements. The participants were differentiated in terms of education, residence and lifestyle (smoking, alcohol drinking). Chi-squared test, product-moment correlations, ANOVA, multiple correspondence analysis (MCA) and logistic regression with backward elimination were used to evaluate associations between social and lifestyle factors and BMI, WHR and W/Ht. The results confirm (1) the relationship between low social status and the risk of overweight and obesity as observed in developed countries; (2) higher susceptibility to environmental factors such as education, place of residence, smoking and alcohol drinking in younger (premenopausal) women; (3) the usefulness of simple and practical anthropometric indicators such as WHR and W/Ht for the identification of the higher risk of future metabolic diseases in obese people and those with a normal body mass.

Assessment of the body mass index and selected physiological parameters in pre- and post-menopausal women

The main purpose of this paper is to describe the variability of the body mass index (BMI) and selected physiological parameters (serum glucose, total serum cholesterol, systolic and diastolic blood pressure) in women before and after menopause. The empirical basis for the assessment is the material obtained in cross-sectional studies carried out in the years 1998-2001 in a group of 2204 women aged 35-65 years, residents of the Wielkopolska region, Poland. The results indicate that hormonal changes taking place in the climacterium bring about an increase in the BMI. It was observed that women receiving Hormone Replacement Therapy in the perimenopause had BMI significantly lower than naturally menopausal women. Increased levels of total serum cholesterol and blood glucose were recorded. The trend has a stronger relation with the age of the subjects than with the character of the menopause. The systolic and diastolic blood pressure values were also found to increase significantly after the menopause, but no relationship with the type of menopause was found.

[Comparative studies of adverse effects in patients with refractory depression treated with amitryptyline, mianserin and unilateral ECT]

The comparative studies of side effects in 180 patients with refractory depression treated with amitriptyline, mianserin and unilateral ECT were performed.