Characterization of the PTB ultra-high pulse dose rate reference electron beam

: Purpose. This investigation aims to present the characterisation and optimisation of an ultra-high pulse dose rate (UHPDR) electron beam at the PTB facility in Germany. A Monte Carlo beam model has been developed for dosimetry study for future investigation in FLASH radiotherapy and will be presented.Material and methods. The 20 MeV electron beams generated by the research linear accelerator has been characterised both in-beamline with profile monitors and magnet spectrometer, and in-water with a diamond detector prototype. The Monte Carlo model has been used to investigate six different setups to enable different dose per pulse (DPP) ranges and beam sizes in water. The properties of the electron radiation field in water have also been characterised in terms of beam size, quality specifierR50and flatness. The beam stability has also been studied.Results. The difference between the Monte-Carlo simulated and measuredR50was smaller than 0.5 mm. The simulated beam sizes agreed with the measured ones within 2 mm. Two suitable setups have been identified for delivering reference UHPDR electron beams. The first one is characterised by a SSD of 70 cm, while in the second one an SSD of 90 cm is used in combination with a 2 mm aluminium scattering plates. The two set-ups are quick and simple to install and enable an expected overall DPP range from 0.13 Gy up to 6.7 Gy per pulse.Conclusion. The electron beams generated by the PTB research accelerator have shown to be stable throughout the four-months length of this investigation. The Monte Carlo models have shown to be in good agreement for beam size and depth dose and within 1% for the beam flatness. The diamond detector prototype has shown to be a promising tool to be used for relative measurements in UHPDR electron beams

Cognitive enhancing drugs: a future challenge for the workplace?

In medical practice, cognitive enhancers (also called nootropics) are defined as therapeutic drugs treating specific cognition impairments in patients with attention deficit hyperactivity disorder, Alzheimer’s disease, stroke schizophrenia or aging. However, the non-medical use of cognitive enhancers with the aim of increasing mental alertness and concentration, improving memory, fighting wakefulness and boosting energy has been spreading worldwide2. In this concern, scarce investigations have been carried out on the possible risks of chronic non-medical use of nootropics, and these risks seem to be largely overlooked, especially among students3. Considering the ever more competitive nature of modern societies, which also reverberates into workplaces, cognitive enhancers are reasonably expected to become even more common over time4. Nonetheless, long-term consequences are as yet unknown. Cognitive enhancers, used by healthy individuals, are widely known as nootropics: they consist of drugs, supplements and other substances that are allegedly known to improve cognitive function, particularly executive functions, and to strengthen memory, creativity or even motivation. Pharmaceutical substances and compounds known as ‘cognitive-enhancers’ allegedly boost mental performance and the ability to focus and keep concentration. In broader terms, such drugs are often claimed to heighten and foster the acquisition of motor capabilities and affective skills (i.e., one’s ability to deal with anxiety stemming from performing certain work tasks or eliciting feelings of trust and affiliation). It is worth noting, however, that no drugs are licensed by medical authorities to be recommended and prescribed as ‘cognitive enhancers’. Thus, the definition of ‘performance-enhancing drug’ is usually linked to the off-label use of drugs prescribed for specific medical conditions. These substances are usually stimulants that preferentially target the catecholamines of the prefrontal cortex of the brain to induce their effects5. Historically, amphetamines have been the first drugs used off-label for the purpose of fostering memory consolidation and increasing concentration6. Since these substances are legally controlled as drugs of abuse, they can only be obtained on illegal markets. This purchase channel is also used to obtain methylphenidate, which is undoubtedly the most misused drug as cognitive enhancer5,7. Mostly prescribed for treating Attention Deficit Hyperactive disorder (ADHD) and narcolepsy, methylphenidate has been scheduled as an illegal drug in many countries for its abuse liability and side effects, resulting in a rapid expansion of methylphenidate legal analogs onto the drug market. Alternative prescription drugs for the treatment of narcolepsy and ADHD, such as modafinil and armodafinil, are also used as cognitive enhancers8. Finally, two last drugs should be mentioned among nootropics: atomoxetine, a selective nor-adrenaline reuptake inhibitor licensed for the treatment of children with methylphenidate-resistant ADHD or undergoing methylphenidate side effects9, and donepezil, a second-generation acetylcholinesterase inhibitor licensed for the treatment of mild to moderately severe symptoms of Alzheimer-related dementia10. At the same time, there has been renewed interest in older prescription drugs (e.g., beta blockers, to decrease performance anxiety) and illicit psychostimulants (e.g., cocaine, amphetamines), sometimes in different forms or doses. Whereas there is still little consensus on the actual effectiveness and nature of the cognitive benefits of the above-mentioned drugs in healthy subjects13, their use to enhance the level of performance in specific workplaces has been reported for decades14. In fact, cognitive enhancement has been a mainstay of military research in the US since the Second World War with the use of amphetamines, modafinil and other cognitive enhancers in the most recent military operations (e.g., Vietnam war, Korean war, operations Desert Shield and Desert Storm in Iraq, later sustained military operations in the Middle East)15,16. Whereas the military use of cognitive enhancers has been known for many years, not only in the US but internationally. More recent studies reported that other occupations present a high prevalence of use: medical doctors and health professionals (e.g., surgeons, surgical technicians’ anesthetists), transportation workers (e.g., truck drivers, car drivers, taxi drivers), financial traders, clinical investigators, research managers and lawyers. Finally, the increase of precarious and part-time home works has been recently associated to psychological discomfort and an increase in prescriptions of psychotropic drugs, and a rise in the misuse of cognitive enhancers can be hypothesized17-19. Another important factor to be taken into account is the role of the internet as a source of information through web forums and as a way of obtaining those substances. Such dynamics also constitute a cultural shift in the way drugs are obtained and consumed: they are anonymously received and safer than street drugs trafficking, although the actual composition and nature of the substances cannot be precisely ascertained. This latter fact creates a gap of information on the diagnosis of misuse in cases of possible intoxications and fatalities, since neither analytical screening nor confirmation methodologies are currently available for documenting exposure to those profuse and chemically diverse substances. In addition, apart from intoxications and fatalities, it has to be reminded that several of these substances present a potential for abuse liability and abstinence symptoms, which, instead of improving work pressure and overload, can worsen the environmental situation. In conclusion, we wish to draw the attention of the whole scientific community and policy makers to the increasing importance of the misuse of cognitive enhancers, and to improve public awareness of the phenomenon and contextual political strategies to stop this incoming threat for the health of current and future worker

Estimating the circularity performance of an emerging industrial symbiosis network: The case of recycled plastic fibers in reinforced concrete

In recent times, the construction industry has been handling circular economy strategies in order to face the most important challenges in the sector, namely the lack of raw materials and the environmental impacts derived from all the processes linked to the entire supply chain. The industrial symbiosis approach represents an effective strategy to improve the circularity of the construction industry. This study analyses the circularity performance of an emerging industrial symbiosis network derived from the production of a cement mortar reinforced with recycled synthetic fibers coming from artificial turf carpets. From the collection of artificial turf carpets at the end-of-life stage it is possible to recover several materials, leading to potential unusual interactions between industries belonging to different sectors. A suitable indicator, retrieved from the literature, the Industrial Symbiosis Indicator (ISI), has been used to estimate the level of industrial symbiosis associated with increasing materials recirculation inside the network. Four scenarios—ranging from perfect linearity to perfect circularity—representing growing circularity were tested. Findings demonstrate that the development of an effective industrial symbiosis network can contribute to improving the circular approach within the construction sector, reducing environmental and economic pressures

Absorbed-dose-to-water measurement using alanine in ultra-high-pulse-dose-rate electron beams

: Objective. The aim of the presented study is to evaluate the dose response of the PTB's secondary standard system, which is based on alanine and electron spin resonance (ESR) spectroscopy measurement, in ultra-high-pulse-dose-rate (UHPDR) electron beams.Approach. The alanine dosimeter system was evaluated in the PTB's UHPDR electron beams (20 MeV) in a range of 0.15-6.2 Gy per pulse. The relationship between the obtained absorbed dose to water per pulse and the in-beamline charge measurement of the electron pulses acquired using an integrating current transformer (ICT) was evaluated. Monte Carlo simulations were used to determine the beam quality conversion and correction factors required to perform alanine dosimetry.Main results. The beam quality conversion factor from the reference quality60Co to 20 MeV obtained by Monte Carlo simulation, 1.010(1), was found to be within the standard uncertainty of the consensus value, 1.014(5). The dose-to-water relative standard uncertainty was determined to be 0.68% in PTB's UHPDR electron beams.Significance. In this investigation, the dose-response of the PTB's alanine dosimeter system was evaluated in a range of dose per pulse between 0.15 Gy and 6.2 Gy and no evidence of dose-response dependency of the PTB's secondary standard system based on alanine was observed. The alanine/ESR system was shown to be a precise dosimetry system for evaluating absorbed dose to water in UHPDR electron beams

Does episiotomy always equate violence in obstetrics? Routine and selective episiotomy in obstetric practice and legal questions

OBJECTIVE: The study’s main goal is to figure out whether episiotomy, a widely applied invasive procedure, may constitute a determining factor of liability for practitioners according to the standards of obstetric violence. MATERIALS AND METHODS: The authors have aimed to analyze laws and documentation issued on the matter by sovereign states, statements and remarks from International health organizations, in addition to scientific article available on the main search engines (PubMed, Scopus, Google Scholar) and legal databases (Lexis, Justia). RESULTS: The body of research has highlighted the existence of a wide-ranging agreement as to routine episiotomy, deemed to be a scientifically unfounded procedure, and which should, therefore, be avoided. By virtue of that, routine episiotomy might easily give rise to charges and liability for doctors and midwives alike; likewise to claims may stem from a failure to perform an episiotomy when it was actually needed. CONCLUSIONS: Unlike routine episiotomy, selective episiotomy is far more unlikely to cause charges of obstetric violence against operators. Unfortunately, the criteria in order to establish when a selective episiotomy is indicated are far from consistent and would require an additional effort on the part of scientific societies towards a more clearly defined and shared description

Heat shock protein expression in canine malignant mammary tumours.

Background Abnormal levels of Heat Shock Proteins (HSPs) have been observed in many human neoplasms including breast cancer and it has been demonstrated that they have both prognostic and therapeutic implications. In this study, we evaluated immunohistochemical expression of HSPs in normal and neoplastic canine mammary glands and confronted these results with overall survival (OS), in order to understand the role of HSPs in carcinogenesis and to establish their potential prognostic and/or therapeutic value. Methods Immunohistochemical expression of Hsp27, Hsp72, Hsp73 and Hsp90 was evaluated in 3 normal canine mammary glands and 30 malignant mammary tumours (10 in situ carcinomas, 10 invasive carcinomas limited to local structures without identifiable invasion of blood or lymphatic vessels, 10 carcinomas with invasion of blood or lymphatic vessels and/or metastases to regional lymph nodes). A semi-quantitative method was used for the analysis of the results. Results Widespread constitutive expression of Hsp73 and Hsp90 was detected in normal tissue, Hsp72 appeared to be focally distributed and Hsp27 showed a negative to rare weak immunostaining. In mammary tumours, a significant increase in Hsp27 (P < 0.01), Hsp72 (P < 0.05) and Hsp90 (P < 0.01) expression was observed as well as a significant reduction in Hsp73 (P < 0.01) immunoreactivity compared to normal mammary gland tissue. Hsp27 demonstrated a strong positivity in infiltrating tumour cells and metaplastic squamous elements of invasive groups. High Hsp27 expression also appeared to be significantly correlated to a shorter OS (P = 0.00087). Intense immunolabelling of Hsp72 and Hsp73 was frequently detected in infiltrative or inflammatory tumour areas. Hsp90 expression was high in all tumours and, like Hsp73, it also showed an intense positivity in lymphatic emboli. Conclusion These results suggest that Hsp27, Hsp72 and Hsp90 are involved in canine mammary gland carcinogenesis. In addition, Hsp27 appears to be implicated in tumour invasiveness and its high immunodetection in invasive tumours is indicative of a poorer clinical outcome

The pasta phase within density dependent hadronic models

In the present paper we investigate the onset of the pasta phase with different parametrisations of the density dependent hadronic model and compare the results with one of the usual parametrisation of the non-linear Walecka model. The influence of the scalar-isovector virtual delta meson is shown. At zero temperature two different methods are used, one based on coexistent phases and the other on the Thomas-Fermi approximation. At finite temperature only the coexistence phases method is used. npe matter with fixed proton fractions and in beta-equilibrium are studied. We compare our results with restrictions imposed on the the values of the density and pressure at the inner edge of the crust, obtained from observations of the Vela pulsar and recent isospin diffusion data from heavy-ion reactions, and with predictions from spinodal calculations.Comment: 15 pages, 11 figures and 7 table

Intrapartum sonography of fetal head in second stage of labor with neuraxial analgesia: a literature review and possible medicolegal aftermath

Intrapartum ultrasound (IU) is a valid support to obstetric management of fetal head progression in the second stage of labor in nulliparous with neuraxial labor analgesia (NLA). Nulliparous with NLA may have a prolonged the second stage of labor. The aim of this literature review was to evaluate the mode of delivery, as well as maternal and fetal morbidities associated with missed progression of fetal head detected with IU in the second stage of labor in nulliparous women with NLA.MATERIALS AND METHODS: The literature review was performed using PubMed, Cochrane, Medline, EMBASE, Scopus, Google Scholar and book chapters searches to identify relevant articles from 2001 to 2019, evaluating the mode of delivery and morbidities of the second stage of labor. Search terms used were “Intrapartum ultrasound”, “dystocia”, “prolonged labor”, “neuraxial analgesia”, “persistent occiput posterior position”, “asynclitism”, “second stage of labor”, “medico-legal aftermath”. Prolonged second stage was defined as three hours and more. Retrospective case series of women with prolonged second stage of labor with NLA were identified. The primary outcome was the incidence of operative vaginal delivery (OVD) and cesarean delivery (CS). RESULTS: The use of NLA may determine a prolonged second stage of labor (PSSL). IU when compared to the traditional vaginal digital examination (VDE) demonstrated the highest degree of diagnostic accuracy. CONCLUSIONS: The use of IU during NLA can aid in the diagnosis of fetal head progression, station or malposition and malrotation, alerts obstetrician on the possibility of dystocic labor, indicating to stop the drug administration in NLA and shift to OVD or CS. Extending the second stage of labor beyond current American College of Obstetricians and Gynecologists (ACOG) recommendations is beneficial. The ISUOG guidelines recommended the clinical application of IU to diagnose the persistent occiput posterior position (POPP) and asynclitism (A) in dystocic labor and produce photographic evidence of the case. Maternal and neonatal complications, medicolegal consequences and litigation can decrease if the IU device is used as good practice

Fiscal policies and car choices in Italy and Norway: A scenario analysis based on a stated-preference survey

Norwegian and Italian car drivers make very different car choices. This paper investigates the influence of fiscal policies on car buyers’ choices, using data collected from a stated preference survey conducted in 2021. After estimating a joint random parameter logit model, we simulated the market shares of five car powertrains under three scenarios: “Italian car buyers face the same net purchase car prices and fuel\electricity costs as the Norwegian car drivers and vice versa”, “Italy adopts the Norwegian registration tax”, and “Both Italy and Norway adopt a social cost internalizing registration tax”. The results indicate that Italian car users are reluctant to switch to battery electric cars (BEVs). They would choose BEVs more frequently in the three scenarios envisaged but without reaching the corresponding Norwegian levels. If Italy would adopt the Norwegian registration tax system, BEVs’ market share would gain 5.4 percentage points relative to the baseline scenario, while under the social cost internalizing scenario, BEVs’ market share would improve by 3.4 and PHEVs’ one by 0.2 percentage points. On the contrary, Norwegians are BEV-oriented and would comparatively preserve a high BEV share. In the social cost internalization scenario, the BEV share relative to the baseline scenario would decrease by 7.2 percentage points, petrol cars would gain 1.2, HEVs 2.9, PHEVs 3.4, and diesel cars would lose 0.3 percentage points. In general, there seems to be a lock-in or path dependence effect that limits BEV penetration in Italy and prevents the decline of the BEV share in Norway