bluuebunny/crossref_metadata_2025 huggingface dataset:
Taxonomic revision of Chamaecrista sect. Absus subsect. Absus (Leguminosae, Caesalpinioideae) with adjustments in the new classification
Authors: SOUZA ALESSANDRO OLIVEIRA DE , GUARDA CAVALCANTE RAPHAEL , JOSÉ DA SILVA MARCOS
Published: September 2022

Chamaecrista, one of the largest genera of Leguminosae with 364 species, had its infrageneric classification recently redefined based on phylogenetic studies, and is now divided into four sections and three subsections. The section Absus, which now includes the section Grimaldia, was subdivided into three subsections: Viscosa, Zygophyllum and Absus, the latter being revised here due to several taxonomic and nomenclatural adjustments that are necessary. Such review resulted from study of specific literature, analysis of ca. 2000 collections of herbariums, including all type collections and expeditions to collect and observe specimens in field. We recognized 18 species to subsection Absus, a new one combination (Chamaecrista major), nine synonymizations and two lectotypifications. The review contains a morphology study of the section and species, an identification key to species, descriptions, illustrations, photographs, maps, updated nomenclature, conservation status, phenology for all species.
Corticospinal Excitability Quantification During a Visually-Guided Precision Walking Task in Humans: Potential for Neurorehabilitation
Authors: Dambreville Charline , Neige Cécilia , Mercier Catherine , Blanchette Andreanne K. , Bouyer Laurent J.
Published: September 2022

The corticospinal tract has been shown to be involved in normal walking in humans. However, its contribution during more challenging locomotor tasks is still unclear. As the corticospinal tract can be a potential target to promote gait recovery after neurological injury, it is of primary importance to quantify its use during human walking. The aims of the current study were to: (1) quantify the effects of precision walking on corticospinal excitability as compared to normal walking; (2) assess if corticospinal modulation is related to task difficulty or participants’ performance. Sixteen healthy participants walked on a treadmill during 2 tasks: regular walking (simple task) and stepping onto virtual targets (precision task). Virtual targets appeared randomly at 3 different step lengths: preferred, and ±20%. To assess corticospinal excitability, 25 motor evoked potentials (MEPs) were recorded from the tibialis anterior muscle in each task during walking. Performance for each participant (global success score; % of target hit) and task difficulty related to step length adjustments (success score for each step length) were also calculated. MEP size was larger during the precision task in all participants (mean increase of 93% ± 72%; P < .05) compared to the simple task. There was a correlation between MEP facilitation and individual performance ( r = −.64; P < .05), but no difference in MEP size associated with task difficulty ( P > .05). In conclusion, corticospinal excitability exhibits a large increase during the precision task. This effect needs to be confirmed in neurological populations to potentially provide a simple and non-invasive approach to increase corticospinal drive during gait rehabilitation.
Functional changes in long-term incubated rat precision-cut lung slices
Authors: Nußbaum Sarah Marie , Krabbe Julia , Böll Svenja , Babendreyer Aaron , Martin Christian
Published: September 2022

Background

Respiratory diseases represent a global health burden. Because research on therapeutic strategies of airway diseases is essential, the technique of precision-cut lung slices (PCLS) has been developed and widely studied. PCLS are an alternative ex vivo model and have the potential to replace and reduce in vivo animal models. So far, the majority of studies was conducted with short-term cultivated PCLS (≤ 72 h). As there is large interest in research of chronic diseases and chronic toxicity, feasibility of cultivating human PCLS long-term over 2 weeks and recently over 4 weeks was investigated by another research group with successful results. Our aim was to establish a model of long-term cultivated rat PCLS over a period of 29 days.

Methods

Rat PCLS were cultured for 29 days and analysed regarding viability, histopathology, reactivity and gene expression at different time points during cultivation.

Results

Cultivation of rat PCLS over a 29-day time period was successful with sustained viability. Furthermore, the ability of bronchoconstriction was maintained between 13 and 25 days, depending on the mediator. However, reduced relaxation, altered sensitivity and increased respiratory tone were observed. Regarding transcription, alteration in gene expression pattern of the investigated target genes was ascertained during long-term cultivation with mixed results. Furthermore, the preparation of PCLS seems to influence messenger ribonucleic acid (mRNA) expression of most target genes. Moreover, the addition of fetal bovine serum (FBS) to the culture medium did not improve viability of PCLS. In contrast to medium without FBS, FBS seems to affect measurements and resulted in marked cellular changes of metaplastic and/or regenerative origin.

Conclusions

Overall, a model of long-term cultivated rat PCLS which stays viable for 29 days and reactive for at least 13 days could be established. Before long-term cultivated PCLS can be used for in-depth study of chronic diseases and chronic toxicity, further investigations have to be made.
Feasibility and acceptability of electronic EQ-5D-5L for routine measurement of HRQOL in patients with chronic musculoskeletal problems in Hong Kong primary care
Authors: Ng Amy Pui Pui , Liu Kiki Sze Nga , Cheng Will Ho Gi , Wong Carlos King Ho , Cheng John King Yiu , Lam Joyce Sau Mei , Or Calvin Kalun , Tse Emily Tsui Yee , Lam Cindy Lo Kuen
Published: September 2022

Background

Information on HRQOL can enhance patient diagnosis and management but it is rarely available in routine clinical practice. This mixed-method study evaluated the feasibility and acceptability of the electronic EQ-5D-5L measurement of HRQOL in patients with chronic musculoskeletal problems in primary care.

Methods

In three primary care clinics, 665 patients with musculoskeletal problems completed the electronic EQ-5D-5L and Visual Analogue Scale (e-EQ-5D-5L/VAS), and a questionnaire on socio-demographics, perceived ease of use (PEOU), and perceived usefulness (PU) at baseline and two follow-ups. Patient completion and response rates, and time to complete the e-EQ-5D-5L/VAS were measured. During the same consultations, 49 doctors reviewed the e-EQ-5D-5L/VAS reports and completed a clinician questionnaire on PEOU, PU, and time spent to address each report. Individual interviews along with focus group discussions were conducted on patients, doctors, and research assistants for further exploration.

Results

Mean completion time reduced from baseline to first and second follow-up (120.66, 83.99, and 105.22 s, respectively). Completion and response rates were high at each follow-up visit (> 99.8% and > 91.11%, respectively). Doctors needed less than 2 min to read the report but felt the time required to address the report was a significant barrier. Some patients had difficulties using e-platforms, in understanding or answering questions; but, PEOU improved with time (p < 0.001). Most patients found the e-platforms useful (> 85.3%). Clinicians agreed a great majority of the reports were easy to use (76.0–85.1%) and useful (69.2–72.0%), particularly aiding with a holistic view of the patient's musculoskeletal problem.

Conclusion

The e-EQ-5D-5L/VAS is a feasible and acceptable measurement of HRQOL of patients with chronic musculoskeletal problems in routine primary care in Hong Kong which can assist real-time management decisions.

Trial registration: NCT03609762.
The immune microenvironment of HPV-positive and HPV-negative oropharyngeal squamous cell carcinoma: a multiparametric quantitative and spatial analysis unveils a rationale to target treatment-naïve tumors with immune checkpoint inhibitors
Authors: Tosi Anna , Parisatto Beatrice , Menegaldo Anna , Spinato Giacomo , Guido Maria , Del Mistro Annarosa , Bussani Rossana , Zanconati Fabrizio , Tofanelli Margherita , Tirelli Giancarlo , Boscolo-Rizzo Paolo , Rosato Antonio
Published: September 2022

Background

Immune checkpoint inhibitors (ICI) are approved for treatment of recurrent or metastatic oropharyngeal head and neck squamous cell carcinoma in the first- and second-line settings. However, only 15–20% of patients benefit from this treatment, a feature increasingly ascribed to the peculiar characteristics of the tumor immune microenvironment (TIME).

Methods

Immune-related gene expression profiling (GEP) and multiplex immunofluorescence (mIF) including spatial proximity analysis, were used to characterize the TIME of 39 treatment-naïve oropharyngeal squamous cell carcinomas (OPSCC) and the corresponding lymph node metastases. GEP and mIF results were correlated with disease-free survival (DFS).

HPV-positive tumors disclosed a stronger activation of several immune signalling pathways, as well as a higher expression of genes related to total tumor-infiltrating lymphocytes, CD8 T cells, cytotoxic cells and exhausted CD8 cells, than HPV-negative patients. Accordingly, mIF revealed that HPV-positive lesions were heavily infiltrated as compared to HPV-negative counterparts, with a higher density of T cells and checkpoint molecules. CD8+ T cells appeared in closer proximity to tumor cells, CD163+ macrophages and FoxP3+ cells in HPV-positive primary tumors, and related metastases. In HPV-positive lesions, PD-L1 expression was increased as compared to HPV-negative samples, and PD-L1+ tumor cells and macrophages were closer to PD-1+ cytotoxic T lymphocytes. Considering the whole cohort, a positive correlation was observed between DFS and higher levels of activating immune signatures and T cell responses, higher density of PD-1+ T cells and their closer proximity to tumor cells or PD-L1+ macrophages. HPV-positive patients with higher infiltration of T cells and macrophages had a longer DFS, while CD163+ macrophages had a negative role in prognosis of HPV-negative patients.

Conclusions

Our results suggest that checkpoint expression may reflect an ongoing antitumor immune response. Thus, these observations provide the rationale for the incorporation of ICI in the loco-regional therapy strategies for patients with heavily infiltrated treatment-naïve OPSCC, and for the combination of ICI with tumor-specific T cell response inducers or TAM modulators for the “cold” OPSCC counterparts.
Burnout syndrome among pediatric dentists in Egypt
Authors: Radwan Mohamed Zayed , Morsy Mahmoud
Published: September 2022

Background

Pediatric dentists in Egypt are exposed to chronic stress associated with pediatric dental care. After long years of specialization, training, and practice, they seem to be unsatisfied. An increased prevalence of burnout could be the reason. This study aimed to determine the prevalence of occupational burnout among Egyptian pediatric dentists.

This study is a cross-sectional, observational study, which was carried by a self-administered online survey questionnaire that was sent to active members in the Egyptian Pediatric Dentistry Associations. A total number of 100 pediatric dentists participated in this study. All of them were offered to fulfill the questionnaires including that of Maslach Burnout Inventory and the semi-structured questionnaire to complete their sociodemographic and work-related data.

Results

It was found that the number of kids raised up by the practitioner is significantly associated with the level of depersonalization. It was also found that the number of working hours per week and number of patients treated per day have a significant association with the level of exhaustion, depersonalization, and personal accomplishment. There were no gender differences in the prevalence of burnout or depression.

Conclusions

Burnout prevalence among pediatric dentist in Egypt is high and higher than its prevalence among other dentists. Marriage and sleeping in home with the family have protective effects against burnout statistically. There is significant association between high number of working hours of the pediatric dentist per week and burnout.
Postoperative hyponatremia in neonates with esophageal atresia and tracheoesophageal fistula receiving restricted hypotonic fluids
Authors: Dogra Shivani , Malik Muneer A. , Peters Nitin J. , Samujh Ram
Published: September 2022

Background

During the postoperative course following neonatal surgery, several stimuli like respiratory distress, pain, and stress cause the release of the antidiuretic hormone which can induce hyponatremia. This hyponatremia due to syndrome of inappropriate antidiuretic hormone secretion (SIADH) in neonates can lead to neurologic impairment and in severe cases can cause significant morbidity and mortality. Lung involvement in neonates undergoing TEF makes this subset of patients vulnerable to this entity because most of them are sick and require ventilation in the postoperative period. The incidence of postoperative hyponatremia following neonatal surgery has not been studied vastly. To the best of our knowledge, this is the first prospective study that has analyzed the incidence of postoperative hyponatremia in this vulnerable population.

Methods

Prospective observational study to assess the incidence of postoperative hyponatremia in neonates with esophageal atresia and tracheoesophageal fistula (EA and TEF) receiving restricted hypotonic fluids. As per the unit policy N/4 5% D is given in the postoperative period. Most neonatal units follow a protocol in which fluid is hiked daily to reach 150 ml/kg/day in 5–7 days. However, in our neonatal surgical unit a protocol to restrict the maintenance fluid at 100 ml/kg/day irrespective of day of life is followed.

Results

Out of a total of 90 neonates (270 sodium measurements), we identified 16 with hyponatremia (11%). Most of the neonates had mild hyponatremia(130–135 meq/l). The incidence of moderate and severe hyponatremia was low.

Conclusion

Postoperative restriction of fluids especially in neonates who are at a high risk for developing SIADH can lead to decreased incidence of severe hyponatremia.
Progressive retinal degeneration of rods and cones in a Bardet-Biedl syndrome type 10 mouse model
Authors: Mayer Sara K. , Thomas Jacintha , Helms Megan , Kothapalli Aishwarya , Cherascu Ioana , Salesevic Adisa , Stalter Elliot , Wang Kai , Datta Poppy , Searby Charles , Seo Seongjin , Hsu Ying , Bhattarai Sajag , Sheffield Val C. , Drack Arlene V.
Published: September 2022

Bardet-Biedl syndrome (BBS) is a multi-organ autosomal-recessive disorder caused by mutations in at least 22 different genes. A constant feature is early-onset retinal degeneration leading to blindness. Among the most common forms is BBS type 10 (BBS10), which is caused by mutations in a gene encoding a chaperonin-like protein. To aid in developing treatments, we phenotyped a Bbs10 knockout (Bbs10−/−) mouse model. Analysis by optical coherence tomography (OCT), electroretinography (ERG) and a visually guided swim assay (VGSA) revealed a progressive degeneration (from P19 to 8 months of age) of the outer nuclear layer that is visible by OCT and histology. Cone ERG was absent from at least P30, at which time rod ERG was reduced to 74.4% of control levels; at 8 months, rod ERG was 2.3% of that of controls. VGSA demonstrated loss of functional vision at 9 months. These phenotypes progressed more rapidly than retinal degeneration in the Bbs1M390R/M390R knock-in mouse. This study defines endpoints for preclinical trials that can be utilized to detect a treatment effect in the Bbs10−/− mouse and extrapolated to human clinical trials.
Neuromechanics of The Rate of Force Development
Authors: Del Vecchio Alessandro
Published: September 2022

The rate at which an individual can develop force during rapid voluntary contractions can be influenced by both the neural drive to a muscle and its intrinsic musculotendinous properties. We hypothesize that the maximal rate of force development across human individuals is mainly attributable to the rate of motor unit recruitment.

Summary for table of contents

The rate of force development varies greatly across individuals. In the present review we discuss the neuromechanical factors that explain this variability.
Ketogenic Diets and Mitochondrial Function: Benefits for Aging but not for Athletes
Authors: Pathak Suraj J. , Baar Keith
Published: September 2022

As humans age, we lose skeletal muscle mass, even in the absence of disease (sarcopenia), increasing the risk of death. Low mitochondrial mass and activity contributes to sarcopenia. It is our hypothesis that, a ketogenic diet improves skeletal muscle mitochondrial mass and function when they have declined due to aging or disease, but not in athletes where mitochondrial quality is high.
Dentists’ perceptions on present and future dental practice during the COVID-19 pandemic: An embedded study
Authors: Shenoy Ramya , Das Deeksha , Mukherjee Megha , Baranya Shrikrishna Suprabha , Denny Ceena , D’Souza Violet
Published: September 2022

Background: The emergence of the COVID-19 pandemic has placed a significant burden on everyone. Although dental professionals are at an increased risk of COVID-19 infection, currently, very little is known about how oral health professionals and their professions could be affected by the pandemic. This study aims to investigate dentists' perceptions on present and future dental practice in light of the COVID-19 pandemic. 

Methods: We conducted an embedded mixed-methods study at Manipal College of Dental Sciences, Mangalore, with Indian dentists registered with the Dental Council of India.  

Results: Of the 976 participating dentists, 61% were females, 32% were 40 years of age or younger. Nearly half of the respondents (54%) acknowledged that the lockdown measures caused them a severe financial burden, and 56% were seriously concerned about being a source of infection to their family, friends, and community. Although 79% felt very comfortable or somewhat comfortable going back to work, they were all worried that Personal Protective Equipment (PPE) use would increase their financial burden and impact the number of patients seeking care. Even though a vast majority received the necessary information regarding returning to practice from their concerned dental regulatory bodies, some were unsure about the reuse of the PPEs because of the conflicting information they received. 

Conclusion: The COVID-19 pandemic affected participants' professional lives negatively. Their major concerns were being a source of infection to their families and community. Providing information to dental professionals in a timely manner may prepare dentists to provide safe care to their patients while protecting themselves, their staff, and their families.
Paravertebral vs. Epidural Analgesia for Liver Surgery (PEALS): Protocol for a randomized controlled pilot study
Authors: Mizubuti Glenio B. , Ho Anthony M.-H. , DuMerton Deborah , Phelan Rachel , Hopman Wilma M. , Cheng Camilyn , Xiong Jessica , Shelley Jessica , Vowotor Elorm , Nanji Sulaiman , Jalink Diederick , Lima Lais Helena Navarro e
Published: September 2022

Background: Perioperative thoracic epidural analgesia (TEA) is commonly used in hepatectomy patients since it is opioid-sparing and reduces cardiorespiratory complications. However, TEA has a high failure rate and is associated with potentially devastating complications (particularly spinal haematoma) and the risk is likely increased with hepatectomy. Thus, some centres favour systemic opioid-based modalities which, in turn, are associated with inferior analgesia and well-known risks/side-effects. Hence, alternative analgesic methods are desirable. Paravertebral block (PVB) has been used in liver resection with advantages including hemodynamic stability, low failure rates, and low risk of spinal haematoma.

Our purpose is to conduct a blinded, pilot RCT with hepatectomy patients randomised to receive TEA or PVB for perioperative analgesia.

Our hypothesis is that opioid consumption, time to first analgesic request, and pain scores will be comparable between groups, but PVB patients will require fewer perioperative vasopressors/blood products, and have fewer adverse events and a shorter hospital stay.

Methods: With ethics approval, this non-inferiority, pilot RCT with a convenience sample of 50 hepatectomy patients will examine whether PVB imparts analgesia comparable to TEA but with fewer adverse effects.

Primary outcomes are surrogates of analgesia for 72 h postoperatively (i.e., opioid consumption, time to first analgesic request and pain scores at rest and with coughing);

Secondary outcomes are blood products/fluids administered; side effects/complications until 72 h postoperatively; length of hospital stay.

The results will be used to plan a large multicentre trial comparing TEA vs. PVB in hepatectomy patients. This study has a high potential to positively impact the quality/safety of patient care.

ClinicalTrials.gov registration: NCT02909322 (09-21-2016); Available at URL: https://clinicaltrials.gov/ct2/show/NCT0290932
Incorporating reading strategies for EFL undergraduate learners in Saudi Arabia: A think-aloud study
Authors: Al-Ahdal Arif Ahmed Mohammed Hassan , Alolaywi Yasamiyan
Published: September 2022

Background: In language learning, reading is a skill that enables interaction with a text in whatever field of knowledge the learner is pursuing. Readers tend to use strategies such as comprehension, interpretation and conception of decoding written language and texts to enhance their reading capacity. This research explores the reading strategies applied by Saudi English as a Foreign Language (EFL) learners and compares the reading abilities of male and female EFL students. Methods: The study interviewed three EFL students about the reading strategies they applied while reading passages and texts. Then an International English Language Testing System (IELTS) reading test was handed over to 26 randomly selected students. Results: The study found that the reading strategies used by the students interviewed involved skimming, scanning, guessing the meaning from context, identifying the mean idea, and summarizing the body of the text in question. Moreover, the study revealed that both male and female students scored low in the IELTS tests that the researchers conducted. The average mean score they reached was 7.15 out of 20. However, even in the low scoring ratio, female students (M=7.69) outperformed male students (M= 6.62) and the difference between them remained significant, P=.000. Conclusions: The study recommends that the language instructors help EFL learners in developing their reading strategies and applying them every time they read any text.
Patterning ECM microstructure to investigate 3D cellular dynamics under multiplexed mechanochemical guidance
Authors: Esfahani Pedram , Sun Bo
Published: September 2022

Background: Biochemical and biophysical factors jointly regulate the cellular dynamics in many physiological processes. It is therefore imperative to include multiplexed microenvironment cues when employing in vitro cell-based assays to model physiological processes.

Methods: To meet this need, we have developed a modular platform of 3D cell culture, Modular Control of Microenvironment for Cell Migration and Culture Assay (MC3A), that incorporates directed chemical and mechanical cues in the forms of chemotaxis and contact guidance, respectively. Taking advantage of the functionalities of MC3A, we study the migration and morphology of breast cancer cells in 3D engineered extracellular matrix (ECM) following a serum gradient for chemotaxis.

Results: We show that when chemotaxis is facilitated by contact guidance in the same direction as the serum gradient, cells demonstrate dimensional-reduction in their motility and highly elongated ellipsoidal shape. When the direction of ECM alignment diverges from the direction of serum gradient, chemotactic motion is significantly suppressed, and cells are generally more protrusive and rounded in their morphology.

Conclusions: These examples demonstrate MC3A as a powerful tool for engineering complex microenvironments of cells that will advance the state-of-the-art of cell-based analysis in drug development, regenerative medicine, and other research areas in bioengineering.
Nicotine products relative risk assessment: an updated systematic review and meta-analysis
Authors: Murkett Rachel , Rugh Megyn , Ding Belinda
Published: September 2022

Background: The nicotine products relative risk assessment estimates the relative risk of tobacco-related diseases due to use of 15 nicotine products. This update adds new data to the original analysis and creates separate categories for United States and rest of world varieties of smokeless tobacco, as well as bidi cigarettes.

Methods: The PubMed®, MEDLINE and Clinicaltrials.gov databases were searched systematically. The study lists were exported, screened at the title, abstract and full-text level according to pre-defined inclusion/exclusion criteria. The study quality was assessed, and risk of bias was accounted for in the screening criteria. The extracted data was synthesized into a toxin emissions/content analysis for 12 Group 1 carcinogens, used to estimate lifetime cancer risk, and epidemiological meta-analysis of over 40 tobacco-related diseases. The two analyses were integrated into a combined risk score for each nicotine product, weighted by the risk of bias due to missing data, and incorporated into the relative risk spectrum.

Results:

In this update, 70 new studies were added to the synthesis, making a total of 123 studies included. All combustible tobacco products score between 40 and 100, with bidis and smokeless (rest of world) also in this range. All other products have a combined risk score of 10 or less, including U.S. chewing tobacco, U.S. dipping tobacco, snus, heat-not-burn tobacco, electronic cigarettes, non-tobacco pouches and nicotine replacement therapy.

Discussion: Consistent with previous studies, we define a group of high-risk nicotine products, scoring between 40 and 100 on the spectrum, and reduced risk nicotine products, scoring less than 10. Limitations of this study include the potential for bias due to missing data, the heterogeneity of the data included in the relative risk hierarchy synthesis, and the assumed consumption levels.
INTERACTION REGIMES FOR HYPERVELOCITY JET AND FLYING PLATE
Authors: DENIZ TANSEL , YILDIRIM R. ORHAN
Published: September 2022

This paper covers the theoretical and numerical simulation studies performed to investigate the interaction of hypervelocity jet and flying plates. The type of interaction between the jet and the flying plate depends on several variables such as the velocity, thickness, obliquity of the flying plate, and the velocity and diameter of the incoming jet. In this study, four modes of interaction between jet and flyer plate, and necessary conditions for each mode of interaction are proposed, depending on the flyer plate and hypervelocity parameters. Then, these conditions are proved with a simulation study. Simulation results are examined both qualitatively by the deflection of the jet and quantitatively by comparison of momentum transfer on the jet. It is seen that conditions for interaction modes are in agreement with simulation results.
THE INFLUENCE OF PREFORMED HOLES ON THE DYNAMIC RESPONSE OF BLAST LOADED ALUMINUM PLATES
Authors: ATOUI OUSSAMA , MOUMEN ABDELHAFIDH , DHOUIBI MOUHAMED , MAAZOUN AZER , BELKASSEM BACHIR , PYL LINCY , LECOMPTE DAVID
Published: September 2022

In this paper, the dynamic response of Aluminum plates with predrilled holes subjected to different intensities of blast loading is studied both experimentally and numerically as to imitate the case where fragments strike and perforate the plates before the load pressure arrives. The blast loading is applied using an Explosive Driven Shock Tube (EDST) [10-12] which ensures a uniformly distributed blast wave on the test specimens. Experiments were carried out for different sizes, positions, and numbers of the predrilled holes in the plates positioned at the end extremity of the tube. Special focus is dedicated to investigate the influence of these parameters on the dynamic response and failure characteristics of plates via the Digital Image Correlation technique (DIC). Numerical simulations were performed in the finite element code LS-DYNA to recreate the plate deformation and the observed phenomena seen in the experiments.
INVESTIGATION ON IMPACT INDUCED ENERGY RELEASE OF PYROPHORIC ALLOY FRAGMENTS USING TIME RESOLVED EMISSION SPECTROSCOPY
Authors: SEIDL MARINA , BORCHERT HARTMUT , FERRARO EVARISTO SANTAMARIA , VUYST T. DE , FADERL NORBERT
Published: September 2022

Technical advancement in material production open new doors in developing reactive material (RM) compounds that combine structural strength with exothermal energetic characteristics. Utilized to exchange inert materials, such as warhead shells, RM enhance the lethal effects. The warhead is initiated, its RM shrapnel accelerated and impact the secondary targets. Upon impact, an impact induced energy release (IIER) occurs in form of exothermal chemical reaction of the RM on the target material. For a repeatable and comparable results, a dedicated experimental set-up has been developed where single cylindrical RM fragments of a diameter D=5 mm and the same length L (L/D=1) represent the shrapnel. They are ballistically driven at initial velocities vi=1500 m/s, using a 7.62 mm powder gun. The RM fragments consists of Ferrocerium, a pyrophoric commercial alloy. Although, Ferrocerium is not primarily a candidate to replace warhead shells, its IIER is academically very suitable for the development of experimental measurement techniques. In order to understand the chemical reaction and quantify the IIER, two parameters are measured, the light emission and the pressure. Time integrated and time-resolved emission spectra, obtained by a Czerny-Turner spectrograph are discussed in this paper. From the investigated wavelength of the oxidation of lanthanum, a predominant compound of the Ferrocerium RM, temperature can be derived between 2300° and 3000° C. In addition, the RM fragment is launched in a closed chamber with pressure sensors and a pressure measurement is taken simultaneously with the light emission. In order to protect against RM enhanced weaponry, the effects of IIER need to be understood.
ANALYSIS OF INTERFACIAL PRESSURE OF ZR-BASED METALLIC GLASS FRAGMENTS IMPACTING TARGET
Authors: WANG GANG , GUO LEI , HE YONG , WANG CHUAN TING , HE YUAN
Published: September 2022

In the present paper, the process of Zr-based metallic glass fragments impacting the target plate is analyzed by one-dimensional stress wave theory to obtain the interfacial pressure between the target and fragments and other relevant influencing parameters. Meanwhile, combing with jh-2 material constitutive model, simulations were conducted to simulate the process of Zr62.5Nb3Cu14.5Ni14Al6 impacting the target plate at the speed of 600m/s-1500m/s with ls-dyna 3d software. The effects of fragments on the process of impacting target plate at different initial velocities were analyzed by combining theory and numerical simulation. The accuracy of jh-2 model for simulating Zr-based reactive fragments impacting steel target at low speed is verified, which can provide a reference for the calculation of reaction threshold of reactive fragments impacting steel target.
FIRST-PRINCIPLES INVESTIGATION OF IMPACT-INDUCED OXIDATION OF REACTIVE MATERIALS
Authors: LANGE CHRISTOPHER , SEIDL MARINA , WÖLBING ROMAN , KRAMER DENIS
Published: September 2022

The strain-dependent oxidation of metals for reactive material warheads is studied with quantum mechanical simulations. A two-stage surface oxidation process was investigated for Titanium, Copper, and Zirconium in unstrained condition and for isotropic compression and tension. The results show exothermic surface oxidation and an increased strain-sensitivity for the pyrophoric materials Titanium and Zirconium in comparison to non-pyrophoric Copper. While tension stabilizes the surface oxidation, compression leads to a destabilization of oxidized surfaces. The release of metal oxides from the oxidized surface is endothermic for all materials in unstrained condition. It was found that the release of metal oxides is stabilized by compression and can even be turned exothermic by sufficient lattice strain.
EXPERIMENTAL VALIDATION OF A NUMERICAL MODEL OF THE 7.62 X 39 M43 PROJECTILE
Authors: AZEVEDO ANA , MIRANDA-VICARIO ANGEL , FREDERIK COGHE FREDERIK , TEIXEIRA-DIAS FILIPE
Published: September 2022

Both in military and in law enforcement operations, the most commonly found small caliber threat is the ubiquitous Kalashnikov, also known as the AK-47 (or simply AK). For that reason, a detailed experimental and numerical study of the 7.62 x 39 M43 projectile was made. In this work, 7.62 x 39 mm mild steel core ammunition was fired against a rigid wall, made of a high-hardness steel plate of sufficient hardness and thickness to respectively avoid denting and bulging, to characterize the projectile core deformation and damage as a function of impact velocity. The validated projectile finite element model can now be used to study more complex impact problems where experimental measurements are complex or impossible. A good qualitative and quantitative correlation between numerical and experimental results for the considered ammunition was achieved.
INFLUENCE OF THE PENETRATOR MATERIAL ON THE DEPTH OF PENETRATION OF TUNGSTEN ALLOY APFSDS PROJECTILES IN AA 7020 T651
Authors: KLAVZAR ANDREAS , MÄGERLEIN NICLAS-BENJAMIN THOMAS , BECKER MARVIN , KRAMER DENIS
Published: September 2022

Experimental and numerical investigations of the penetration of APFSDS projectiles in semi-infinite targets of Mars® 380 and AA 7020 T651 are presented in this work. Two different tungsten heavy alloy penetrator materials with different strengths have been used. In armor steel the material of the penetrator was found to have only a minor influence on the depth of penetration. In the AA 7020 T651 targets the influence of the penetrators strength was found to be important, especially as at lower velocities the penetration process does not lead to an erosion of the projectile. With the numerical simulation the deforming penetration process could be reproduced, but more effort is necessary to evaluate a reliable strength model parameter set.
REVIEW OF TERMINAL BALLISTICS OF A BULLET IN THE HUMAN BODY
Authors: COLDWELL DOUGLAS
Published: September 2022

The terminal ballistics of a projectile in the human body are reviewed, both the theory, experimental data, and their implications for medical/surgical treatment. The focus of the past century has been to increase the kinetic energy of the bullet but ignoring the material from which the bullet, firing chamber, and target are made. The more efficient delivery of this kinetic energy to the target is proportional to the damage caused. The bullet causes a tract through the impacted tissues that is related to the size of the projectile, but the accompanying shock wave causes a much larger temporary cavity which, depending on the structure and elasticity of the tissue, will stay patent for only 2-4sec. Surgical resection of the permanent tract containing injured tissue, bullet fragments, and contaminated material is initially performed followed by the repair of the tissues injured by the bullet.
DATA ON DECELERATION HISTORY OF BODY IN RHEOLOGICAL MEDIUM AS A BASIS FOR VERIFY OF TERMINAL BALLISTICS CALCULATED TASKS
Authors: SOTSKIY MIKHAIL , VELDANOV VLADISLAV
Published: September 2022

The reports materials on the data presented by the authors earlier in the proceedings of 23rd- 31st International Symposiums on Ballistics are base. The results relate to the field of study of the action of the body on the target. Measuring technology is a set of methodological, technological and software components for tests measuring strikers-probes. Such strikers are equipped with impact accelerometers and original systems for connect with recorder. The difference from the known methods is the realizable range of impact velocities: 100 - 2500 m/s at the stage of action on the target. Theoretical and experimental studies have revealed a new law of medium resistance to penetration. The law allows the application of engineering methods for solving problems. It became possible to solve spatial tasks of penetration with the use of this law.
APPLICATION OF THE BUILDING BLOCK APPROACH (BBA) FOR LIGHT WEIGHT PERSONAL ARMOUR MATERIALS CALIBRATION
Authors: MESPOULET JEROME , ABDULHAMID HAKIM , PEYRATOUT MAËLLE , DECONINCK PAUL
Published: September 2022

This paper presents a lightweight armor structure calibration method. The armor consists of a stacking of two materials: a ceramic tile and a backing made of UHMWPE (Ultra High Molecular Weight Polyethylene) plate. Using a building block approach, each material is characterized separately before studying the response of the resulted structure under ballistic impact. For the ceramic material, Hugoniot and spall parameters are identified using plate impact tests. Then, data from dynamic confined compression tests on SHPB (Split Hopkinson Pressure Bars) are used to complete the model. The characterization of the composite backing is realized using a dynamic press (tension), SHPB (out-of-plane compression) and gas gun (out-of-plane shear). The out-of-plane shear configuration test has been specifically designed to highlight the behavior of the composite material. Experimental data are used to calibrate a non-linear orthotropic material model with damage for the composite plate and a JH-2 material model for the ceramic. Moreover, the modelling of inter-ply interaction appears to be predominant to correctly reproduce the ballistic behavior of UHMWPE. The model of each material has been validated in a ballistic test configuration using a sphere for the composite and a rod projectile for the ceramic. Additional tests were conducted to study the ballistic response of the stacking (ceramic tile + UHMWPE) with a more realistic 7.62mm projectile
« Je t’aime moi non plus »
Authors: Loison-Charles Julie
Published: September 2022

“JE T’AIME MOI NON PLUS”: THE CORRESPONDENCE BETWEEN VLADIMIR NABOKOV AND HIS FRENCH TRANSLATORS

The structure of the letters which Vladimir Nabokov sent to his French translators shows how ambivalent his relation to them was: generally, Nabokov starts by praising the beauty of the translation, and then he makes a long list of all the blunders and howlers made by the translator. This article studies three cases. First, the translation of Pale Fire is analysed as a confrontation of two very proud men, in which the famous translator Maurice Edgar Coindreau refuses to be bossed around by the novelist. Then the article presents the translation of Ada or Ardor (entrusted to Gilles Chahine) as the collaboration of “men on the verge of a nervous breakdown”. Finally, it shows the very friendly relationship which Nabokov had with Jarl Priel, the translator of Invitation to a Beheading, whom Nabokov always fiercely defended. Thanks to the correspondence between Nabokov, his translators and publishers, it will become clear that these collaborative translations were in fact “mediated self-translations”. For Nabokov, it was not just about translating his novels: he wanted to remain the full master of his creations.
Krzysztof Jarosz – traducteur multifonctionnel
Authors: Warmuzińska-Rogóż Joanna
Published: September 2022

KRZYSZTOF JAROSZ – A MULTIFUNCTIONAL TRANSLATOR: ABOUT THE FRANKOFONIA LITERARIA COLLECTION

This article focuses on the translator’s roles that go beyond the traditional functions of the literary translator. Based on the example of the Frankofonia Literaria series and the works of Ananda Devi published in Polish in Krzysztof Jarosz’s translation, the author of the article demonstrates how the translator “comes out of the shadows,” in particular by serving as an exegete-interpreter and researcher. The translator makes himself visible in paratexts, such as footnotes or an afterword, which constitute a space where he presents himself and allows himself to be seen and read alongside the literary text.
Ethical moments and institutional expertise in UK Government COVID-19 pandemic policy responses: where, when and how is ethical advice sought?
Authors: Pykett Jessica , Ball Sarah , Dingwall Robert , Lepenies Robert , Sommer Theresa , Strassheim Holger , Wenzel Lars
Published: September 2022

Background:

The emergency response to the COVID-19 pandemic has required a rapid acceleration of policy decision making, and raised a wide range of ethical issues worldwide, ranging from vaccine prioritisation, welfare and public health ‘trade-offs’, inequalities in policy impacts, and the legitimacy of scientific expertise.

Aims and objectives:

This paper explores the legacy of the pandemic for future science-advice-policy relationships by investigating how the UK government’s engagement with ethical advice is organised institutionally. We provide an analysis of some key ethical moments in the UK Government response to the pandemic, and institutions and national frameworks which exist to provide ethical advice on policy strategies.

Methods:

We draw on literature review, documentary analysis of scientific advisory group reports, and a stakeholder workshop with government ethics advisors and researchers in England.

Findings:

We identify how particular types of ethical advice and expertise are sought to support decision making. Contrary to a prominent assumption in the extensive literature on ‘governing by expertise’, ethical decisions in times of crisis are highly contingent.

Discussion and conclusions:

The paper raises an important set of questions for how best to equip policymakers to navigate decisions about values in situations characterised by knowledge deficits, complexity and uncertainty. We conclude that a clearer pathway is needed between advisory institutions and decision makers to ensure ethically-informed debate.
A cross-sectional examination of the early-onset hypertensive disorders of pregnancy and industrial emissions of toxic metals using Kentucky birth records, 2008–2017
Authors: Walker Courtney J. , Christian W. Jay , Kucharska-Newton Anna , Browning Steven R.
Published: September 2022

This cross-sectional study assessed geospatial patterns of early-onset hypertensive disorders of pregnancy (eHDP) in primiparous mothers and exposure to industrial emissions using geocoded residential information from Kentucky live (N = 210,804) and still (N = 1,247) birth records (2008–2017) and census block group estimates of aerosol concentrations of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), selenium (Se), and zinc (Zi) from the Risk Screening Environmental Indicators (RSEI) model. A latent class analysis allowed for the identification of four district exposure classes—As, Cd, and Pb (12.6%); Se and Zi (21.4%); Pb and Cr (8%); and low or no exposures (57.9%). Women classified as having a high probability of exposure to both Pb and Cr had a statistically significantly greater prevalence of eHDP after adjusting for demographic factors (aPR = 1.22, 95% CI: 1.04, 1.44) relative to those with low or no exposure. Our findings contribute to the emerging literature on the association of metal exposures with pregnancy outcomes.
Air pollution in Delhi, India: It’s status and association with respiratory diseases
Authors: Dutta Abhishek , Jinsart Wanida
Published: September 2022

The policymakers need research studies indicating the role of different pollutants with morbidity for polluted cities to install a strategic air quality management system. This study critically assessed the air pollution of Delhi for 2016–18 to found out the role of air pollutants in respiratory morbidity under the ICD-10, J00-J99. The critical assessment of Delhi air pollution was done using various approaches. The mean PM2.5 and PM10 concentrations during the measurement period exceeded both national and international standards by a wide margin. Time series charts indicated the interdependence of PM2.5 and PM10 and connection with hospital visits due to respiratory diseases. Violin plots showed that daily respiratory disease hospital visits increased during the winter and autumn seasons. The winter season was the worst from the city’s air pollution point of view, as revealed by frequency analyses. The single and multi-pollutant GAM models indicated that short-term exposure to PM10 and SO2 led to increased hospital visits due to respiratory diseases. Per 10 units increase in concentrations of PM10 brought the highest increase in hospital visits of 0.21% (RR: 1.00, 95% CI: 1.001, 1.002) at lag0-6 days. This study found the robust effect of SO2 persisted in Delhi from lag0 to lag4 days and lag01 to lag06 days for single and cumulative lag day effects, respectively. While every 10 μg m-3 increase of SO2 concentrations on the same day (lag0) led to 32.59% (RR: 1.33, 95% CI: 1.09, 1.61) rise of hospital visits, the cumulative concentration of lag0-1 led to 37.21% (RR: 1.37, 95% CI:1.11, 1.70) rise in hospital visits which further increased to even 83.33% (RR: 1.83, 95% CI:1.35, 2.49) rise at a lag0-6 cumulative concentration in Delhi. The role of SO2 in inducing respiratory diseases is worrying as India is now the largest anthropogenic SO2 emitter in the world.
A pan-cancer bioinformatic analysis of the carcinogenic role of SMARCA1 in human carcinomas
Authors: Dai Lei , Mugaanyi Joseph , Zhang Tongyue , Tong Jingshu , Cai Xingchen , Lu Caide , Lu Changjiang
Published: September 2022

SMARCA1is a mammalian imitation switch (ISWI) gene that encodes for SNF2L. SNF2L is involved in regulating cell transition from a committed progenitor state to a differentiated state. Although many papers have detailed the correlation between SMARCA1 and different cancers, no pan-cancer analysis has been conducted to date. We started by exploring the potential carcinogenic role of SMARCA1 across 33 carcinomas using the cancer genome atlas (TCGA) and the genotype-tissue expression (GTEx) databases. The expression of SMARCA1 was significantly elevated in some tumor types but not in others. There was a distinct relationship between SMARCA1 expression and patient prognosis. S116 phosphorylation levels were up-regulated in both lung adenocarcinoma and uterine corpus endometrial carcinoma. The expression level of SMARCA1 was positively correlated with cancer-associated fibroblasts infiltration in a number of tumors, such as colon adenocarcinoma, cervical squamous cell carcinoma and endocervical adenocarcinoma. It was also associated with CD8+ T-cell infiltration in head and neck squamous cell carcinoma and lung adenocarcinoma. Furthermore, SMARCA1 is involved in chromatin remodeling and protein processing-associated mechanisms. Our study presents an initial assessment and illustration of the carcinogenic role of SMARCA1 in different carcinomas.