bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of environmental conditions on the degradation of rubber compounds
Authors: Markovičová L , Zatkalíková V
Published: February 2024

Rubber compounds are complex, chemically active and viscoelastic materials. In this material type, transient and transient changes in the individual rubber properties occur during the manufacturing processes. A large number of rubber compounds consist of a large number of elastomers and virtually all of them are made up of fillers such as (carbon black, silica, kaolin, calcium carbonate, etc.). A very important element of which rubber compounds are composed is sulphur. Its important function is to ensure the cross-linking process during vulcanisation. Lubricants, plasticizers and various organic substances used to modify the properties are also essential components of rubber compounds. The aim of this work is to assess the influence of natural environmental conditions (temperature, time, humidity, microorganisms, UV radiation) on the modification of the properties of rubber composites.
The effect of long-term exposure in mixed sulfuric acid and copper sulfate solution on corrosion behavior of austenitic stainless steels
Authors: Zatkalíková V , Markovičová L
Published: February 2024

Corrosion resistance of austenitic stainless steels in sulfuric acid solutions depends mainly on concentration and temperature of the sulfuric acid, the presence of contaminants and velocity flow. Current studies aim mostly at evaluation of electrochemical parameters in sulfuric acid solutions. Research focused on long-term exposure is lacking. This article deals with the corrosion behavior of AISI 304 and AISI 316L stainless steels in mixed 10 wt. % sulfuric acid and 10 wt. % copper sulfate solution. Sensitized (650 °C/40 hours) and solution annealed (1050 °C/15 min) specimens together with the untreated (as received) ones are evaluated by long-term (22-month) exposure immersion test at the temperature of 22 ± 3 °C on the bases of optical microscopy, SEM and mass losses. Both tested stainless steels in as received and solution annealed state proved high corrosion resistance in the given corrosive environment. The cross-sections edges of sensitized specimens revealed a close relationship between local corrosion sites and weakened grain boundaries, which indicates incipient intergranular corrosion.
Analysis of Biocompatible Metallic Materials used in Medicine
Authors: Gerhátová Ž , Paták J , Babincová P , Hudáková M , Palcut M
Published: February 2024

The paper presents the results of the analysis of two biocompatible materials, Kirschner wires of different thicknesses. Kirschner wires (K-wires) are stainless steel pins used in surgery to fix bone fragments and to provide an anchor for skeletal traction. The K-wires are produced in different diameters. In the present work, a scanning electron microscopy and light microscopy were employed to document the microstructure of two K-wires with different thicknesses. Before observation, the wires were prepared by a standard metallographic procedure (grinding and polishing) followed by electrolytic etching. The chemical composition was determined by studying the wires using quantitative energy-dispersive X-ray spectrometry. It has been found that the chemical composition of the materials corresponds to Cr-Ni stainless steel. In the thick Kirschner wire (sample no. 1) a deformed microstructure after drawing was observed. Sample no. 2 (thin Kirschner wire), on the other hand, consisted of polyhedral austenitic grains, which were formed after recrystallization annealing. Furthermore, isolated microparticles were observed and assigned to titanium nitride. A Vickers hardness test was also performed on the samples. It has been found that the hardness of sample no. 1 was 428.8 HV 0.5. The average hardness of sample no. 2 was 213.4 HV 0.5. It can be concluded that recrystallization annealing decreases the hardness of the material. The K-wires with smaller diameter are thus easier to bend which facilitates their fixation in human body.
Statistical evaluation of hard-to-measure surfaces
Authors: Kubišová M , Knedlová J , Vrbová H , Pata V , Bočáková B
Published: February 2024

The main goal of this article will be to find ways to evaluate hard-to-measure surfaces statistically. First, the basic characteristics and rules of surface quality will be described according to the standards ČSN EN 4287, ČSN EN 4288 and ČSN EN ISO 2517-2. Subsequently, the measured values of the roughness parameter Sa (arithmetic average of the height of the measured surface) and Sz (the maximum height of the measured surface) will be compared and evaluated which is the best. These parameters will be described and measured on aluminium plates on which the test surfaces were laser engraved. To evaluate the best surface, statistical methods will be used, such as the EDA methodology (exploratory data analysis), hypothesis testing with normality and outlier tests, and last but not least, cluster or cluster analysis, which compares the similarity of the measured data. This article aims to show the possibilities of surface quality assessment using 3D surface roughness parameters, which are not often used in practice.
Ion Beam Analysis including ToF-ERDA of complex composition layers
Authors: Dobrovodský J , Vaňa D , Beňo M , Lofaj F , Riedlmajer R
Published: February 2024

When developing new materials for example, for high-temperature nuclear reactors with the potential of hydrogen production, that are characterized by radiation, high temperature and corrosion resistance, it is indispensable the knowledge of their detailed elemental composition and its possible variation with depth from surface. Several analytical methods based on different physical principles are used to determine the depth distribution of elements in the surface layers of materials. For the quantitative determination of elemental depth profile to a depth of several micrometres are applicable established Ion Beam Analysis (IBA) methods such as RBS, EBS, NRA and ERDA. Their advantage is that they are considered to be absolute and to a certain extent non-destructive. Each of these methods is advantageously used to analyse a certain range of elements, sometimes depending on the combination of other elements present. The recently commissioned Time of Flight Elastic Recoil Analysis (ToF-ERDA) measuring system at the Slovak University of Technology MTF in Trnava significantly enhanced the Ion Beam Laboratory capability of a comprehensive elemental analysis of thin films to the depth of hundreds of nanometres. Using the primary analysing 50 MeV Au beam, the depth profiles of all elements from W to H can be obtained within a single measurement. Analysis of complex samples using traditional IBA methods and high-energy ToF-ERDA is discussed and compared. The first measurements on the new ToF-ERDA installation are also presented.
Eco-friendly synthesis of mesoporous bioactive glass ceramics and functionalization for drug delivery and hard tissue engineering applications
Authors: Tabassum Sobia , Saqib Muhammad , Batool Madeeha , Sharif Faiza , Gilani Mazhar Amjad , Huck Olivier
Published: February 2024

Hard tissue regenerative mesoporous bioactive glass (MBG) has traditionally been synthesized using costly and toxic alkoxysilane agents and harsh conditions. In this study, MBG was synthesized using the cheaper reagent SiO2 by using a co-precipitation approach. The surface properties of MBG ceramic were tailored by functionalizing with amino and carboxylic groups, aiming to develop an efficient drug delivery system for treating bone infections occurring during or after reconstruction surgeries. The amino groups were introduced through a salinization reaction, while the carboxylate groups were added via a chain elongation reaction. The MBG, MBG-NH2, and MBG-NH-COOH were analyzed by using various techniques: x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), scanning electron microscopy and energy-dispersive x-ray spectroscopy. The XRD results confirmed the successful preparation of MBG, and the FTIR results indicated successful functionalization. BET analysis revealed that the prepared samples were mesoporous, and functionalization tuned their surface area and surface properties. Cefixime, an antibiotic, was loaded onto MBG, MBG-NH2, and MBG-NH-COOH to test their drug-carrying capacity. Comparatively, MBG-NH-COOH showed good drug loading and sustained release behavior. The release of the drug followed the Fickian diffusion mechanism. All prepared samples displayed favorable biocompatibility at higher concentration in the Alamar blue assay with MC3T3 cells and exhibited the good potential for hard tissue regeneration, as carbonated hydroxyapatite formed on their surfaces in simulated body fluid.
Synthesis and characterization of 3-in-1 multifunctional lipiodol-doped Fe3O4@Poly (diallyl isophthalate) microspheres for arterial embolization, chemotherapy, and imaging
Authors: Chen Piaoyi , Xiao Qinglin , Guo Zhaoxiong , Liang Wei , Liu Ou , Lin Liteng , Huang Yugang , Zhu Kangshun , Ye Guodong
Published: February 2024

Transcatheter arterial embolization plays a pivotal role in treating various diseases. However, the efficacy of embolization therapy in cancer treatment can be limited by several factors, such as inevitable incomplete or non-target embolization, and the tumor recurrence and metastasis caused by the hypoxic microenvironment. Moreover, it is essential to explore simpler, more economical, and efficient methods for microsphere synthesis. Herein, we achieved one-step photocatalytic synthesis of lipiodol-doped Fe3O4@Poly (diallyl iso-phthalate) multifunctional microspheres (IFeD MS) for arterial embolization, chemotherapy, and imaging. The prepared microspheres are in the shape of dried plums, with a particle size of 100–300 μm. Lipiodol demonstrates a certain degree of chemotherapeutic activity, and the incorporation of Fe3O4 enables the microspheres to exhibit magnetothermal response and magnetic resonance imaging capabilities. Furthermore, the radiopaque characteristics of both agents provide the microspheres with promising potential for computed tomography and digital radiography imaging. The renal embolization experiment in rabbits demonstrated that IFeD MS achieved significant embolization and chemotherapeutic effects. Biocompatibility experiments revealed that this embolic agent did not induce tissue damage or inflammation beyond the treatment area. Additionally, IFeD MS exhibited promising imaging potential. The results of this study imply that the developed multifunctional embolic agent IFeD MS may have significant potential in transforming tumors previously only suitable for palliative cares into resectable radical treatments.
Mechanical fabrication and evaluation of bioresorbable barbed sutures with different barb geometries
Authors: Nambi Gowri Karuna , King Martin W
Published: February 2024

Bioresorbable polymeric sutures are gaining interest from surgeons and patients as they reduce surgical stress and trauma. This study involves two bioresorbable polymers, namely, catgut and poly(4-hyrdorxybutyrate) (P4HB) that are used widely in cosmetic procedures. P4HB barbed sutures are favorably used in rhytidectomy (micro-facelifts) procedures while catgut sutures are widely used for external wound closure after surgical interventions. This study involves the mechanical fabrication of catgut and P4HB barbed sutures and compares their mechanical and anchoring properties. Barbed sutures were fabricated with two different barb geometries namely, straight and curved barbs. The mechanical properties were evaluated via tensile testing, and the anchoring performance was studied by means of a suture-tissue pull-out protocol using porcine dermis tissue which was harvested from the medial dorsal site. The fabricated barbed sutures of both materials showed a similar trend compared to non-barbed sutures of decreases in failure stress, strain at failure, and work to rupture or toughness which was reduced by about 70%. At the same time there was a 15% increase in the initial modulus or stiffness of the barbed sutures. The pull-out force for the barbed sutures with straight barbs was similar for both P4HB (5.04 ± 0.8 N) and catgut (4.47 ± 3.8 N), and as expected, were higher than that of non-barbed sutures of the same size. It was also observed that barbed sutures with curved barbs also required a higher pull-out force than those sutures with straight barbs. It was concluded that by barbing sutures with different barb shapes and geometries, a range of barbed suture products could be fabricated, each meeting the closure requirements for different types of tissue and therefore being suitable for different surgical procedures.
Gibbs sampling the posterior of neural networks
Authors: Piccioli Giovanni , Troiani Emanuele , Zdeborová Lenka
Published: February 2024

In this paper, we study sampling from a posterior derived from a neural network. We propose a new probabilistic model consisting of adding noise at every pre- and post-activation in the network, arguing that the resulting posterior can be sampled using an efficient Gibbs sampler. For small models, the Gibbs sampler attains similar performances as the state-of-the-art Markov chain Monte Carlo methods, such as the Hamiltonian Monte Carlo or the Metropolis adjusted Langevin algorithm, both on real and synthetic data. By framing our analysis in the teacher-student setting, we introduce a thermalization criterion that allows us to detect when an algorithm, when run on data with synthetic labels, fails to sample from the posterior. The criterion is based on the fact that in the teacher-student setting we can initialize an algorithm directly at equilibrium.
Clinicopathologic features and survival outcomes of CD30 expression in extranodal natural killer/T-cell lymphoma
Authors: Shen Ziyuan , Wang Yubo , Xie Ruiyang , Zhang Qing , Xing Xing , Zhang Shuo , Liu Hui , Sang Wei
Published: February 2024

Objectives

Previous studies have been inconsistent concerning the association between the prognostic value of CD30 expression and extranodal natural killer/T-cell lymphoma (ENKTL).

Methods

CD30 expression in 82 patients with newly diagnosed ENKTL (mean age, 50 years; 73.2% male) was assessed by immunohistochemistry on paraffin-embedded sections. The level of CD30 expression was categorized into negative (0%, no staining) and positive groups.

Results

Sixty-seven cases exhibited positive CD30 expression, and the main between-group difference was the Chinese Southwest Oncology Group and Asia Lymphoma Study Group (CA) ENKTL stage and Eastern Cooperative Oncology Group (ECOG) performance status. The cutoff point for CD30 expression was 40% by restricted cubic splines analysis. The overall survival of patients with high expression (>40%) was statistically superior to negative (0%) and low-expression groups. A positive correlation was observed between CD30 and Epstein-Barr virus–encoded small RNA status (r = 0.305). Multivariable analysis suggested that positive CD30 expression (hazard ratio, 0.420 [95% CI, 0.193-0.914]; P = .029) and CA advanced stage (hazard ratio, 2.844 [95% CI, 1.371-5.896]; P = .005) were independent prognostic factors for ENKTL.

Conclusions

Positive CD30 expression was a favorable prognostic factor for ENKTL, and CD30 expression could restratify the survival of patients in clinical subgroups.
Child Criminal Exploitation and the Interactional Emergence of Victim Status
Authors: Marshall Hannah
Published: February 2024

This article draws on observations and interviews with youth justice practitioners and young people involved in county lines drug dealing to explore the processes by which young people are identified as victims of child criminal exploitation (CCE). The findings reveal that interpersonal interactions between practitioners and young people, specifically young people’s capacity to share information and accept intended acts of care, are vital in producing their status as CCE victims. Yet, a lack of appreciation for young people’s divergent experiences of these interactions can create barriers to their realization. The article concludes by exploring the implications of these processes for contemporary youth justice practice, and by questioning the utility of CCE victim identification as a response to children experiencing harm.
Thepparatia vines (Hibisceae subtribe Trionum) phylogenomics and evolution
Authors: Landrein Sven , Song Shi-Jie , Zhang Jie , Guo Yong-Jie , Shen Jian-Yong , Jiang Qiu-Yu , Low Shook Ling
Published: February 2024

Hibisceae subtribe Trionum is the largest clade within Hibiscus s.l. and contains genera with a wide range of growth forms: herbaceous (Abelmoschus), shrubs (Malvaviscus), trees (Wercklea), and exceptionally lianas. The rare and localized Thepparatia species are unique in that they combine a lianescent habit and trioecy.

Several problems have delayed the study of Hibisceae classification including low genetic variability, lack of synapomorphic morphological characters, transoceanic dispersal events, and allopolyploidy. Here, we present a comprehensive phylogenomic hypothesis of Thepparatia based on analyses of the maternally inherited chloroplast and biparentally inherited nuclear ribosomal cistron sequences, and compare these results with its speciation, karyology, and breeding system.

Chloroplast genomes in subtribe Trionum were highly conserved except in Abelmoschus where four additional genes were duplicated. Recent diploid interspecific hybridization is suggested in Thepparatia sipsongpannaensis between T. fragrans and T. scandens during the Pleistocene, around 640 000 years ago. Our observations also indicate Thepparatia have a trioecious breeding system that combined with a unique habit, and a highly localized distribution pattern, have created cross-pollination barriers and ecological specialization. This suggests hybridization events are rare but evolutionary significant in subtribe Trionum.

Finally, our study supports important nomenclature changes: the synonymization of Hibiscus austroyunnanensis with Thepparatia fragrans and the publication of a new species, Thepparatia sipsongpannaensis.
Functional connectivity key feature analysis of cognitive impairment patients based on microstate brain network
Authors: Li Zipeng , Qu Zhongjie , Yin Bowen , Yin Liyong , Li Xin
Published: February 2024

Mild cognitive impairment (MCI) is the initial phase of Alzheimer’s disease (AD). The cognitive decline is linked to abnormal connectivity between different regions of the brain. Most brain network studies fail to consider the changes in brain patterns and do not reflect the dynamic pathological characteristics of patients. Therefore, this paper proposes a method for constructing brain networks based on microstate sequences. It also analyzes the microstate temporal parameters and introduces a new feature, the brain homeostasis coefficient (Bhc), to quantify the stability of patient brain connections. The results showed that microstate class B parameters were higher in the MCI than in the HC group. Additionally, the Bhc values in most channels of the MCI and AD groups were lower than those of the HC group, with the most significant differences observed in the right frontal lobe. These differences were statistically significant (P < 0.05). The findings indicate that connectivity in the right frontal lobe may be most severely disrupted in patients with cognitive impairment. Furthermore, the Montreal Cognitive Assessment score showed a strong positive correlation with Bhc. This suggests that Bhc could be a novel biomarker for evaluating cognitive function in patients with cognitive impairment.
Risk of incident chronic kidney disease among patients with urolithiasis: a nationwide longitudinal cohort study
Authors: Kim Jae Young , Lee Jae Kwang , Park Jung Tak , Chang Tae Ik
Published: February 2024

Background

Urolithiasis has been infrequently implicated to have a causal association with chronic kidney disease (CKD). Recently, several studies have demonstrated the relationship between urolithiasis and CKD. However, the generalizability of their results is limited. This study aimed to investigate the association between urolithiasis and the risk of incident CKD.

Methods

This longitudinal cohort study used the National Health Insurance Service data, including 219 570 Korean adults with incident urolithiasis requiring procedural interventions and without prior kidney disease and 219 570 age- and sex-matched controls without urolithiasis between 1 January 2002 and 31 December 2020. Primary outcome was the development of CKD, defined by an estimated glomerular filtration rate <60 ml/min/1.73 m2 for at least two consecutive measurements at least 90 days apart. The risk for incident CKD was further examined using the outcome defined by newly occurring diagnostic codes indicating CKD.

Results

Over a mean follow-up of 6 years, 12 338 (2.8%) primary outcome events of CKD were observed (incidence rate 4.6/1000 person-years). Per multivariable Cox analysis, urolithiasis was associated with a higher risk of incident CKD [adjusted hazard ratio 1.41 (95% confidence interval 1.36–1.46)]. This association remained consistent across all clinically relevant subgroups and when the CKD outcome was defined based on the diagnostic codes in the sensitivity analysis.

Conclusions

In this large national cohort study, patients with urolithiasis were associated with a higher risk of incident CKD than those without urolithiasis. Further studies are warranted to establish the benefits of preventing urolithiasis in reducing CKD development.
Thromboxane biosynthesis and future events in diabetes: the ASCEND trial
Authors: Petrucci Giovanna , Buck Georgina A , Rocca Bianca , Parish Sarah , Baigent Colin , Hatem Duaa , Mafham Marion , Habib Aida , Bowman Louise , Armitage Jane , Patrono Carlo
Published: February 2024

Background and Aims

Thromboxane (TX) A2, released by activated platelets, plays an important role in atherothrombosis. Urinary 11-dehydro-TXB2 (U-TXM), a stable metabolite reflecting the whole-body TXA2 biosynthesis, is reduced by ∼70% by daily low-dose aspirin. The U-TXM represents a non-invasive biomarker of in vivo platelet activation and is enhanced in patients with diabetes. This study assessed whether U-TXM is associated with the risk of future serious vascular events or revascularizations (SVE-R), major bleeding, or cancer in patients with diabetes.

Methods

The U-TXM was measured pre-randomization to aspirin or placebo in 5948 people with type 1 or 2 diabetes and no cardiovascular disease, in the ASCEND trial. Associations between log U-TXM and SVE-R (n = 618), major bleed (n = 206), and cancer (n = 700) during 6.6 years of follow-up were investigated by Cox regression; comparisons of these associations with the effects of randomization to aspirin were made.

Results

Higher U-TXM was associated with older age, female sex, current smoking, type 2 diabetes, higher body size, urinary albumin/creatinine ratio of ≥3 mg/mmol, and higher estimated glomerular filtration rate. After adjustment for these, U-TXM was marginally statistically significantly associated with SVE-R and major bleed but not cancer [hazard ratios per 1 SD higher log U-TXM (95% confidence interval): 1.09 (1.00–1.18), 1.16 (1.01–1.34), and 1.06 (0.98–1.14)]. The hazard ratio was similar to that implied by the clinical effects of randomization to aspirin for SVE-R but not for major bleed.

Conclusions

The U-TXM was log-linearly independently associated with SVE-R in diabetes. This is consistent with the involvement of platelet TXA2 in diabetic atherothrombosis.
In-hospital safety outcomes of left atrial appendage occlusion in octogenarians and nonagenarians
Authors: Ismayl Mahmoud , Ahmed Hasaan , Goldsweig Andrew M , Freeman James V , Alkhouli Mohamad
Published: February 2024

Aims

Data on safety outcomes of left atrial appendage occlusion (LAAO) in elderly patients are limited. This study aimed to compare the outcomes of LAAO between octogenarians (age 80–89) and nonagenarians (age ≥90) vs. younger patients (age ≤79).

Methods and results

We conducted a retrospective cohort study using the National Inpatient Sample database to identify patients hospitalized for LAAO from 2016 to 2020 and to compare in-hospital safety outcomes in octogenarians and nonagenarians vs. younger patients. The primary outcome was a composite of in-hospital all-cause mortality or stroke. Secondary outcomes included procedural complications, length of stay (LOS), and total costs. Outcomes were determined using logistic regression models. Among 84 140 patients hospitalized for LAAO, 32.9% were octogenarians, 2.8% were nonagenarians, and 64.3% were ≤79 years of age. Over the study period, the volume of LAAO increased in all age groups (all Ptrend < 0.01). After adjustment for clinical and demographic factors, octogenarians and nonagenarians had similar odds of in-hospital all-cause mortality or stroke [adjusted odds ratio (aOR) 1.41, 95% confidence interval (CI) 0.93–2.13 for octogenarians; aOR 1.69, 95% CI 0.67–3.92 for nonagenarians], cardiac tamponade, acute kidney injury, major bleeding, and blood transfusion, in addition to similar LOS and total costs compared with younger patients (all P > 0.05). However, octogenarians and nonagenarians had higher odds of vascular complications compared with younger patients (aOR 1.47, 95% CI 1.08–1.99 for octogenarians; aOR 1.60, 95% CI 1.18–2.97 for nonagenarians).

Conclusion

Octogenarians and nonagenarians undergoing LAAO have a similar safety profile compared with clinically similar younger patients except for higher odds of vascular complications.
High-Quality Genome Assemblies of 4 Members of the Podospora anserina Species Complex
Authors: Ament-Velásquez S Lorena , Vogan Aaron A , Wallerman Ola , Hartmann Fanny E , Gautier Valérie , Silar Philippe , Giraud Tatiana , Johannesson Hanna
Published: February 2024

The filamentous fungus Podospora anserina is a model organism used extensively in the study of molecular biology, senescence, prion biology, meiotic drive, mating-type chromosome evolution, and plant biomass degradation. It has recently been established that P. anserina is a member of a complex of 7 closely related species. In addition to P. anserina, high-quality genomic resources are available for 2 of these taxa. Here, we provide chromosome-level annotated assemblies of the 4 remaining species of the complex, as well as a comprehensive data set of annotated assemblies from a total of 28 Podospora genomes. We find that all 7 species have genomes of around 35 Mb arranged in 7 chromosomes that are mostly collinear and less than 2% divergent from each other at genic regions. We further attempt to resolve their phylogenetic relationships, finding significant levels of phylogenetic conflict as expected from a rapid and recent diversification.
Interpreting generative adversarial networks to infer natural selection from genetic data
Authors: Riley Rebecca , Mathieson Iain , Mathieson Sara
Published: February 2024

Understanding natural selection and other forms of non-neutrality is a major focus for the use of machine learning in population genetics. Existing methods rely on computationally intensive simulated training data. Unlike efficient neutral coalescent simulations for demographic inference, realistic simulations of selection typically require slow forward simulations. Because there are many possible modes of selection, a high dimensional parameter space must be explored, with no guarantee that the simulated models are close to the real processes. Finally, it is difficult to interpret trained neural networks, leading to a lack of understanding about what features contribute to classification. Here we develop a new approach to detect selection and other local evolutionary processes that requires relatively few selection simulations during training. We build upon a generative adversarial network trained to simulate realistic neutral data. This consists of a generator (fitted demographic model), and a discriminator (convolutional neural network) that predicts whether a genomic region is real or fake. As the generator can only generate data under neutral demographic processes, regions of real data that the discriminator recognizes as having a high probability of being “real” do not fit the neutral demographic model and are therefore candidates for targets of selection. To incentivize identification of a specific mode of selection, we fine-tune the discriminator with a small number of custom non-neutral simulations. We show that this approach has high power to detect various forms of selection in simulations, and that it finds regions under positive selection identified by state-of-the-art population genetic methods in three human populations. Finally, we show how to interpret the trained networks by clustering hidden units of the discriminator based on their correlation patterns with known summary statistics.
A statistical framework for detection ofb-value anomalies in Italy
Authors: Lombardi Anna Maria
Published: February 2024

This study presents a new robust statistical framework, in which to measure relative differences, or deviations from a hypothetical reference value, of Gutenberg–Richter b-value. Moreover, it applies this method to recent seismicity in Italy, to find possible changes of earthquake magnitude distribution in time and space. The method uses bootstrap techniques, which have no prior assumptions about the distribution of data, keeping their basic features. Excluding Central Italy, no significative b-value variation is found, revealing that the frequency–magnitude distribution exponent is substantially stable or that data are not able to reveal hidden variations. Considering the small size of examined magnitude samples, we cannot definitively decide if the higher b-values in Central Italy, consistently founded by all applied tests, have a physical origin or result from a statistical bias. In any case, they indicate short-lived excursions which have a temporary nature and, therefore, cannot be associated solely to spatial variations in tectonic framework. Both the methodological issues and the results of the application to seismicity in Italy show that a correct assessing of b-value changes requests appropriate statistics, that accurately quantify the low accuracy and precision of b-value estimation for small magnitude samples.
Why do we use 100 mg of clofazimine in TB and NTM treatment?
Authors: van Ingen Jakko
Published: February 2024

Current tuberculosis and non-tuberculous mycobacterial disease guidelines recommend the use of clofazimine in a 100 mg once-daily dose. The rationale behind this exact dose is not provided.

I performed a literature review to determine the reasoning behind the current dosing regimen. The current 100 mg once-daily dose of clofazimine stems from a deliberate attempt to find the minimum effective daily dose in leprosy treatment, driven by efficacy, economical and toxicity considerations.

While this dose is safe, economical and practical, a higher dose with a loading phase may add relevant efficacy and treatment-shortening potential to both tuberculosis and non-tuberculous mycobacterial disease treatment. We need to revisit dose–response and maximum tolerated dose studies to get the best out of this drug, while continuing efforts to generate more active r-iminophenazine molecules that accumulate less in skin and intestinal tissues and have pharmacokinetic properties that do not require loading doses.
What is philosophy of education? Overlaps and contrasts between different conceptions
Authors: White John
Published: February 2024

Various conceptions of philosophy of education have been mooted over the last sixty years. The paper looks at five of these, associated particularly with R. S. Peters, D. W. Hamlyn, David Bakhurst, Philip Kitcher, and Harvey Siegel. It shows differences and sometimes overlaps among these, to do with whether or not philosophy of education should be seen as a branch of philosophy, as central to philosophy as a whole, or as a form of applied philosophy. The paper puts most weight on the last of these while recognizing the importance of work on the enculturation of young human beings as exemplified in Hamlyn’s and Bakhurst’s writings.
The Dynamics of Generics
Authors: Kirkpatrick James Ravi
Published: February 2024

It is a familiar point that we can use generic sentences to express generalisations that are tolerant to exceptions and then go on to state those exceptions explicitly. It is a less familiar point that switching the order of the generics has deleterious effects on their felicity. For example, the sequences ‘Ravens are black, but albino ravens aren’t’ is perfectly felicitous and judged to be true, whereas its reverse ‘Albino ravens aren’t black, but ravens are’ is infelicitous and contradictory-sounding. This paper argues that such sequences pose a problem for extant theories of generics: while they have no trouble predicting the felicity of the first sequence of generics, they are unable to explain why reversing the order results in infelicity. I propose to account for these observations by adopting a dynamic semantic theory of generic sentences.
Characterization of the cryptic interspecific hybrid Lemna×mediterranea by an integrated approach provides new insights into duckweed diversity
Authors: Braglia Luca , Ceschin Simona , Iannelli M Adelaide , Bog Manuela , Fabriani Marco , Frugis Giovanna , Gavazzi Floriana , Gianì Silvia , Mariani Flaminia , Muzzi Maurizio , Pelella Emanuele , Morello Laura
Published: February 2024

Lemnaceae taxonomy is challenged by the particular morphology of these tiny free-floating angiosperms. Although molecular taxonomy has helped clarify the phylogenetic history of this family, some inconsistency with morphological data leads to frequent misclassifications in the genus Lemna. Recently, the finding that Lemna japonica is an interspecific hybrid between Lemna minor and Lemna turionifera provided a clear explanation for one such taxonomic question. Here we demonstrated that L. minor is also capable of hybridizing with Lemna gibba, generating a cryptic but widespread taxon in the Mediterranean area. The nothotaxon Lemna ×mediterranea is described and compared with clones of the putative parental species L. minor and L. gibba. Genetic analysis by nuclear and plastid markers, as well as genome size measurement, revealed that two different cytotypes, diploid and triploid, originated by at least two independent hybridization events. Despite high overall similarity, morphometrical, physiological, and biochemical analyses showed an intermediate position of L. ×mediterranea between its parental species in most qualitative and quantitative characters, and also separation of the two hybrid cytotypes by some criteria. These data provide evidence that hybridization and polyploidization, driving forces of terrestrial plant evolution, contribute to duckweed genetic diversity and may have shaped the phylogenetic history of these mainly asexual, aquatic plants.
Hyperspectral imaging reveals small-scale water gradients in apple leaves due to minimal cuticle perforation by Venturia inaequalis conidiophores
Authors: Oerke Erich-Christian , Steiner Ulrike
Published: February 2024

Effects of Venturia inaequalis on water relations of apple leaves were studied under controlled conditions without limitation of water supply to elucidate their impact on the non-haustorial biotrophy of this pathogen. Leaf water relations, namely leaf water content and transpiration, were spatially resolved by hyperspectral imaging and thermography; non-imaging techniques—gravimetry, a pressure chamber, and porometry—were used for calibration and validation. Reduced stomatal transpiration 3–4 d after inoculation coincided with a transient increase of water potential. Perforation of the plant cuticle by protruding conidiophores subsequently increased cuticular transpiration even before visible symptoms occurred. With sufficient water supply, cuticular transpiration remained at elevated levels for several weeks. Infections did not affect the leaf water content before scab lesions became visible. Only hyperspectral imaging was suitable to demonstrate that a decreased leaf water content was strictly limited to sites of emerging conidiophores and that cuticle porosity increased with sporulation. Microscopy confirmed marginal cuticle injury; although perforated, it tightly surrounded the base of conidiophores throughout sporulation and restricted water loss. The role of sustained redirection of water flow to the pathogen’s hyphae in the subcuticular space above epidermal cells, to facilitate the acquisition and uptake of nutrients by V. inaequalis, is discussed
Scaling responses
Authors: Streiner David L. , Norman Geoffrey R. , Cairney John
Published: February 2024

This chapter presents various ways of presenting the response options to the respondent. It begins by discussing why dichotomous responses (e.g. yes/no, true/false) are often inadequate. Different alternatives are discussed, including direct estimation methods (e.g. visual analogue scales, adjectival scales, Likert scales), comparative methods (e.g. paired comparisons, Guttman scaling), and econometric methods. It reviews some of the issues that need to be considered in writing the response options, such as whether one should use a unipolar or bipolar scale, how many steps there should be, and whether all the response options need to be labelled. It also covers what statistical tests can legitimately be used with scales. Finally, it compares ratings with rankings, and introduces the method of multidimensional scaling.
From items to scales
Authors: Streiner David L. , Norman Geoffrey R. , Cairney John
Published: February 2024

This chapter discusses various issues that are involved in combining individual items to form a single scale. The topics covered include whether or not to weight each of the items to reflect its supposed importance. Another consideration is whether items should be weighted differently for each person based on their salience or importance to that individual. Related to this is ‘implicit’ weighting, where various subscales of an instrument have differing numbers of items. The chapter then discusses various ways of transforming the final score in order to normalize them. Finally, it describes different methods of setting cut points based on the distribution and expert judgement.
Validity
Authors: Streiner David L. , Norman Geoffrey R. , Cairney John
Published: February 2024

In order for a scale to be useful, the user must be able to draw accurate conclusions about the presence or absence of the attribute being measured. This is the domain of validity. What validity is and how it is assessed has changed greatly since the 1960s, although many who develop or validate scales are unaware of this. This chapter discusses what is meant by validity and how it is assessed. The major points are that: (1) validity is not a property of the test, but may change depending on the sample and the conditions under which the test is given, and (2) there are not different ‘types’ of validity—they are all various aspects of construct validity. The chapter also describes different types of studies that can establish construct validity.
Measuring change
Authors: Streiner David L. , Norman Geoffrey R. , Cairney John
Published: February 2024

Although the goal of many clinical assessments and research studies is to measure how much people change between two occasions, the measurement of change is fraught with conceptual and methodological difficulties. One of the difficulties is that there are (at least) two different reasons to measure change: to determine if intervention had any effect, and to identify the correlates of change. These two goals work against each other, because the former requires there to be little difference in the amount of change among people in the same group, while the latter depends on inter-individual differences. The chapter also discusses various biases that exist when people are asked directly how much they think they have changed. This chapter addresses the issues of the relationship of change to the reliability of the scale, difficulties of measuring change in experimental and quasi-experimental studies, and new approaches to measuring change, such as growth curve analysis.
Item response theory
Authors: Streiner David L. , Norman Geoffrey R. , Cairney John
Published: February 2024

Since the 1960s, there has been a revolution in the approach to scale development. Called item response theory (IRT), this approach challenges the notion that scales must be long in order to be reliable, and that psychometric properties of a scale derived from one group of people cannot be applied to different groups. This chapter provides an introduction to IRT, and discusses how it can be used to develop scales and to shorten existing scales that have been developed using the more traditional approach of classical test theory. IRT also can result in scales that have interval level properties, unlike those derived from classical test theory. Further, it allows people to be compared to one another, even though they may have completed different items, allowing for computerized adaptive testing. The chapter concludes by discussing the advantages and disadvantages of IRT.
Ethical considerations
Authors: Streiner David L. , Norman Geoffrey R. , Cairney John
Published: February 2024

Although studies of the psychometric properties of scales do not have the same ethical challenges as those involving interventions, there are still areas that researchers need to be sensitive to. These include issues such as informed consent, especially with vulnerable populations, and deception. This chapter also discusses confidentiality, and when this can be breached for legal reasons. It returns to the issue of consequential validity and the ethical issues that may arise when minority or disadvantaged groups attain scores that are different from those of the majority population. This chapter discusses these and other ethical problems that may arise within the context of developing and validating scales.
Emergencies in Supportive and Palliative Care
Authors: Currow David , Clark Katherine , Kleinig Paul
Published: February 2024

Supportive and palliative care continues to evolve rapidly because of the increasing understanding of the pathophysiology of bodies under stress and the ability to intervene with less catabolic stress or other harms. This opens new ways of providing palliation for what were previously intractable problems. As such, there is a need to understand the role of focused history taking, careful physical examination, and the prognosis of the person. From this, the most appropriate support can be considered which may, at times, include interventions to address the underlying cause of the symptom, not simply the symptom alone. This book helps to guide each step when sudden or unexpected changes occur in a person’s condition. The book helps to frame thinking about the overall health of the person, their comorbidities, and their life expectancy before this change. With careful evaluation, a patient-centred approach can help to optimize the person’s outcomes, in line with their (informed) wishes.
Haematological disorders
Authors: Currow David , Clark Katherine , Kleinig Paul
Published: February 2024

Haematological disorders may be the basis of the person’s life-limiting illness, but often accompany other illnesses. Bleeding or the threat of bleeding, and clotting both cause problems and, understandably, generate anxiety. It is often a very overt sign of someone’s illness. Similarly, uncontrolled sepsis can cause a rapid and irreversible decline in a person’s condition unless it is detected early. As such, this requires a very high index of suspicion in order to deliver the best outcomes to the person.
Unrelenting Insulin Release: Sulfonylurea/Meglitinide Overdose
Authors: Sheneman Matthew , Murray Brian P. , Carpenter Joseph E.
Published: February 2024

Sulfonylureas are a group of medications whose primary function is to combat elevated blood glucose levels in persons with type II diabetes mellitus (DM II). Sulfonylureas do this by increasing the release of the hormone insulin from the pancreatic beta cells, thus counteracting the decreased sensitivity to insulin seen in DM II. Sulfonylureas are oral medications that in overdose or in the setting of acute kidney injury and impaired renal clearance can cause refractory and profound hypoglycemia, which paradoxically can be made worse by dextrose administration. The antidote octreotide can antagonize the action of sulfonylureas, limiting insulin release and helping to restore euglycemia.
Don’t Lose Your Ear Over Cardiac Glycosides: Cardiac Glycoside Toxicity Management
Authors: Howell Marshall , Fahmy Girgis , Kiernan Emily
Published: February 2024

Digoxin is a cardioactive glycoside derived from the naturally occurring compound digitoxin, which is found in the foxglove plant. Digoxin functions via blockade of the myocardial Na+-K+-ATPase and by increasing vagal tone, leading to positive inotropic effects and slowed AV nodal conduction. At therapeutic levels, digoxin can rate control atrial fibrillation and alleviate symptoms of congestive heart failure. In acute or chronic toxicity, mild symptoms begin with GI distress but may progress to lethargy, confusion, weakness, and color vision changes. In severe toxicity, digoxin causes derangement of intra- and extracellular potassium, calcium, and magnesium concentrations resulting in myocardial desensitization and potential for fatal tachy- or bradyarrhythmias. Toxic patients may be hemodynamically unstable, and definitive treatment is prompt administration of digoxin-specific Fab fragments.
GABA-B, the Forgotten Receptor Overlooked No More: Baclofen Overdose and Withdrawal
Authors: Hoffmann Nicholas , Bernstein Jay
Published: February 2024

Baclofen, beta-chlorophenyl-GABA (Lioresal, Gablofen, Kemstro, Lyvispah, Ozobax), is the only commonly prescribed GABA-B agonist, used for muscle spasticity and pain caused by cerebral palsy, traumatic or ischemic neurologic injuries, multiple sclerosis, or other neurodegenerative disorders. It is commonly administered orally but can also be delivered intrathecally via a surgically implanted pump in patients 4 years of age or older for cases refractory to oral therapy. GABA-B receptors are widely expressed in the nervous tissue of the brain and spinal cord, and baclofen binds receptors with primarily inhibitory effects. As in any acute intoxication or withdrawal that presents to the ED, early airway protection and aggressive supportive care, a broad differential diagnosis, and identification of possible complicating factors are key to prevent morbidity and mortality. Being aware of nonconvulsive status epilepticus, underlying intrathecal pump infections, and the potential for prolonged CNS depression that can mimic brain death must be considered in baclofen overdose.
Is That Chest Pain a Heart Attack, or a Line of Cocaine? Managing Cocaine-Induced Chest Pain
Authors: Mansour Amir Jamal , Padmanabhan Pradeep , Assi Besher
Published: February 2024

Cocaine is the second most commonly used illicit drug in the United States, only behind marijuana, with more than 5.5 million users. Cocaine exerts its effects via inhibition of monoamine reuptake at the synapse as well as sympathetic system activation. It is associated with accelerated atherosclerosis, vasospasm, and vasoconstriction of coronary arteries; worsens hypertension; and increases platelet aggregation, all of which can lead to chest pain and myocardial ischemia. The treatment of cocaine-associated chest pain is similar to patients with traditional cardiac risk factors other than the emphasis on the use of benzodiazepines, nitroprusside, and phentolamine as well as the avoidance of beta-blockers. Disposition of these patients can be challenging; recent literature has suggested better outcomes with observation for at least 9–12 hours along with serial troponins and ECGs to help guide decision-making in these patients.