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Background: The safety profile of COVID-19 vaccines in immunocompromised patients has not been comprehensively evaluated. Aim: To measure the frequency of patient-reported adverse drug reactions (ADRs) related to the first/second/booster dose of COVID-19 vaccine in immunocompromised subject versus matched cohort. As a secondary objective, the time course, evaluated as time to onset (TTO) and time to recovery (TTR), of COVID-19 vaccine-related ADRs was explored. Methods: A prospective cohort study, based on electronic questionnaires filled by vaccinees from 11 European countries in the period February 2021 to February 2023 was conducted. All immunocompromised vaccinees who provided informed consent and registered to the project's web-app within 48 h after first/booster vaccine dose administration of any EMA-authorised COVID-19 vaccine were recruited. Participants filled baseline and up to six follow-up questionnaires (FU-Qs) over 6 months from vaccination, collecting information on suspected COVID-19 vaccine-related ADRs. As a control group, non-immunocompromised vaccinees from the same source population were 1:4 matched by sex, age, vaccine dose, and brand. A descriptive analysis of demographic/clinical characteristics of vaccinees was conducted. Heatmaps of the frequency of solicited ADRs, stratified by gender and vaccine brand, were generated. Median TTO/TTR of reported ADRs were visualised using violin/box-plots. Results: A total of 773 immunocompromised vaccines were included in the analyses. Most participants were females (F/M ratio: 2.1 and 1.6) with a median age of 56 (43–74) and 51 (41–60) years, at the first vaccination cycle and booster dose, respectively. Injection-site pain and fatigue were the most frequently reported ADRs in immunocompromised vaccinees with higher frequency than matched control, especially after the first dose (41.2% vs 37.8% and 38.2% vs 32.9%, respectively). For both cohorts, all solicited ADRs were more frequently reported in females than males, and in those who had received a first dose of the Vaxzevria vaccine. Dizziness was the most frequently reported unsolicited ADR after the first dose in both groups (immunocompromised subjects: 2.5% and matched controls: 2.1%). At the booster dose, lymphadenopathy (3.9%) and lymphadenitis (1.8%) were the most reported unsolicited ADRs for immunocompromised subjects and matched controls, respectively. A very low number of subjects reported adverse event of special interest (AESI) (2 immunocompromised, 3 matched controls) and serious ADRs (5 immunocompromised, 5 matched controls). A statistically significant difference among study cohorts was observed for median TTO after the booster dose, and for median TTR after the first vaccination cycle and booster dose (p < 0.001). Conclusion: The overall safety profile of COVID-19 vaccines in immunocompromised people was favourable, with minor differences as compared to non-immunocompromised vaccinees. Participants mostly experienced mild ADRs, mainly reported after the first dose of Vaxzevria and Jcovden vaccines. Serious ADRs and AESI were rare. [ABSTRACT FROM AUTHOR]

Introduction: In 2021, the European Medicines Agency supported the "Covid Vaccine Monitor (CVM)," an active surveillance project spanning 13 European countries aimed at monitoring the safety of COVID-19 vaccines in general and special populations (i.e., pregnant/breastfeeding women, children/adolescents, immunocompromised people, and people with a history of allergies or previous SARS-CoV-2 infection). Italy participated in this project as a large multidisciplinary network called the "ilmiovaccinoCOVID19 collaborating group." Methods: The study aimed to describe the experience of the Italian network "ilmiovaccinoCOVID19 collaborating group" in the CVM context from June 2021 to February 2023. Comprising about 30 partners, the network aimed to facilitate vaccinee recruitment. Participants completed baseline and follow-up questionnaires within 48 h from vaccination over a 6-month period. Analyses focused on those who completed both the baseline and the first follow-up questionnaire (Q1), exploring temporal trends, vaccination campaign correlation, and loss to follow-up. Characteristics of recruited vaccinees and vaccineereported adverse drug reactions (ADRs) were compared with passive surveillance data in Italy. Results: From June 2021 to November 2022, 22,384,663 first doses and 38,207,452 booster doses of COVID-19 vaccines were administered in Italy. Simultaneously, the study enrolled 1,229 and 2,707 participants for the first and booster doses, respectively. Of these, 829 and 1,879 vaccinees, respectively, completed both baseline and at least Q1 and were included in the analyses, with a significant proportion of them (57.8%/34.3%) belonging to special cohorts. Most vaccinees included in the analyses were women. Comirnaty® (69%) and Spikevax® (29%) were the most frequently administered vaccines. ADR rates following Comirnaty® and Spikevax® were higher after the second dose, particularly following Spikevax®. Serious ADRs were infrequent. Differences were observed in ADR characteristics between CVM and Italian passive surveillance. Conclusion: This study confirmed the favorable safety profile of COVID-19 vaccines, with findings consistent with pivotal clinical trials of COVID-19 vaccines, although different proportions of serious ADRs compared to spontaneous reporting were observed. Continuous evaluation through cohort event monitoring studies provides real-time insights crucial for regulatory responses. Strengthening infrastructure and implementing early monitoring strategies are essential to enhance vaccine safety assessment and prepare for future pandemics. [ABSTRACT FROM AUTHOR]

The dichromatic number ...(D) of a digraph D is the least integer k such that D can be partitioned into k directed acyclic digraphs. A digraph is k-dicritical if ...(D) = k and each proper subgraph D' of D satisfies ...(-D') ≤ k - 1. An oriented graph is a digraph with no directed cycle of length 2. For integers k and n, we denote by Ok(n) the minimum number of edges of a k-dicritical oriented graph on n vertices. The main result of this paper is a proof that O3(n) ≥ 7n+2/3 together with a construction witnessing that O3(n) ≤ ⌈5n/2⌉ for all n ≥ 12. We also give a construction showing that for all sufficiently large n and all k ≥ 3, Ok(n) < (2k -- 3)n, disproving a conjecture of Hoshino and Kawarabayashi. [ABSTRACT FROM AUTHOR]

The French humanist and reformer Nicolas de Clamanges (ca. 1363/64-1437) wrote a blistering treatise against new feasts, De nouis festiuitatibus, which contrasts with his related sermon praising the holy innocents, De sanctis innocentibus. This contrast is ironic because their feast during the Christmas season had become the occasion for out-of-control celebrations known as the Feast of Fools, especially in Clamanges' northern France. This essay uncovers and contextualizes his complaints within his style of reform: he uses the early church as a model, for instance, and launches into rhetorical flourishes, especially in the sermon. The essay also compares Clamanges' positions with those of his classmate Jean Gerson (1363-1429) and their shared mentor at the University of Paris Pierre d'Ailly (1351-1420). All three hoped that good devotions come from good intentions, but both intention and devotion must be patrolled for superstition and excess. [ABSTRACT FROM AUTHOR]

Summary: Background: Tibial perineural analgesia has often been reported to fail to achieve nerve desensitisation in horses. Ultrasound‐guided (US‐guided) techniques have recently been described to improve tibial perineural desensitisation. Objectives: To compare US‐guided and 'blind' tibial perineural analgesia techniques in lameness investigation. Study design: Randomised clinical trial. Methods: Horses presenting for lameness investigation, which required tibial perineural analgesia, were randomly assigned either to a US‐guided or blind injection group. The efficacy of perineural analgesia was assessed by testing the loss of skin sensation at the medial and lateral heel bulbs. Skin sensation was assessed, prior to injection and then at four intervals post‐injection (10–15, 20–25, 30–35 and 40–45 min) using a hand‐held digital algometer with a 1 mm diameter pin; a value of 25 N was defined as indicative of skin desensitisation. The time taken to perform each injection technique and any adverse reactions were recorded. Summary statistics were performed to examine differences between groups. The frequency of skin desensitisation was compared between groups using a Fisher's exact test and the length of time taken to perform injections was compared using a Mann–Whitney U test. Results: Sixteen US‐guided and 11 blind injections were included in the study. All cases undergoing US‐guided injection lost skin sensation, whereas this occurred in only one case receiving the blind injection. The US‐guided group had a significantly higher probability of skin sensation loss (p < 0.001), although the injection technique took significantly longer to complete compared to the blind group (p < 0.001). No adverse reactions were noted with either perineural injection technique. Main limitations: Limited number of cases for each injection group. Conclusions: These findings suggest that US‐guided tibial perineural injection is more likely to result in adequate and prompt tibial perineural analgesia compared to the blind injection technique, although it takes longer to complete. [ABSTRACT FROM AUTHOR]

A coloring of a digraph is a partition of its vertex set such that each class induces a digraph with no directed cycles. A digraph is k-chromatic if k is the minimum number of classes in such partition, and a digraph is oriented if there is at most one arc between each pair of vertices. Clearly, the smallest k-chromatic digraph is the complete digraph on k vertices, but determining the order of the smallest k-chromatic oriented graphs is a challenging problem. It is known that the smallest 2-, 3- and 4-chromatic oriented graphs have 3, 7 and 11 vertices, respectively. In 1994, Neumann-Lara conjectured that a smallest 5-chromatic oriented graph has 17 vertices. We solve this conjecture and show that the correct order is 19. [ABSTRACT FROM AUTHOR]

A dominating set in a directed graph is a set of vertices S such that all the vertices that do not belong to S have an in-neighbour in S. A locating set S is a set of vertices such that all the vertices that do not belong to S are characterized uniquely by the in-neighbours they have in S , i.e. for every two vertices u and v that are not in S , there exists a vertex s ∈ S that dominates exactly one of them. The size of a smallest set of a directed graph D which is both locating and dominating is denoted by γ L D (D). Foucaud, Heydarshahi and Parreau proved that any twin-free digraph D satisfies γ L D (D) ≤ 4 n 5 + 1 but conjectured that this bound can be lowered to 2 n 3. The conjecture is still open. They also proved that if D is a tournament, i.e. a directed graph where there is exactly one arc between every pair of vertices, then γ L D (D) ≤ ⌈ n 2 ⌉. The main result of this paper is the generalization of this bound to connected local tournaments, i.e. connected digraphs where the in- and out-neighbourhoods of every vertex induce a tournament. We also prove γ L D (D) ≤ 2 n 3 for all quasi-twin-free digraphs D that admit a supervising vertex (a vertex from which any vertex is reachable). This class of digraphs generalizes twin-free acyclic graphs, the most general class for which this bound was known. [ABSTRACT FROM AUTHOR]

Summary: An 18‐year‐old Warmblood gelding was presented for investigation of a large, firm mass over the medial and plantar aspect of the left distal metatarsal and fetlock region. The mass was first identified 4 months prior to referral, following a traumatic incident, and had over time gradually increased in size. Clinical examination and diagnostic imaging revealed a large soft tissue mass adjacent to the metatarsophalangeal joint and digital flexor tendon sheath, with no overt involvement of underlying bone. The mass was surgically excised under general anaesthesia using a harmonic scalpel with limited margins to avoid compromise of adjacent anatomical structures. Following histology, the mass was diagnosed as a fibrosarcoma. Twelve months after surgical resection, no signs of recurrence were evident. This report demonstrates that fibrosarcoma of the equine distal limb may be successfully managed with surgical excision. The use of a harmonic scalpel should be considered as an alternative to sharp excision when treating fibrosarcoma or other infiltrative tumours, particularly those located in regions where only limited surgical margins may be achieved. [ABSTRACT FROM AUTHOR]

Homomorphically full graphs are those for which every homomorphic image is isomorphic to a subgraph. We extend the definition of homomorphically full to oriented graphs in two different ways. For the first of these, we show that homomorphically full oriented graphs arise as quasi-transitive orientations of homomorphically full graphs. This in turn yields an efficient recognition and construction algorithms for these homomorphically full oriented graphs. For the second one, we show that the related recognition problem is GI-hard, and that the problem of deciding if a graph admits a homomorphically full orientation is NP-complete. In doing so we show the problem of deciding if two given oriented cliques are isomorphic is GI-complete. [ABSTRACT FROM AUTHOR]

Purpose: With an increase in the number of adapted sports, the need to monitor sports performance in people with different abilities has grown. Indeed, a thorough evaluation of the sports gesture could prevent the occurrence of injuries, enable a continuous performance assessment, and allow to verify the compliance of the requirements for the competitions. Gesture kinematics provides an assessment of performance, while the muscle activities reveal the underlying strategies adopted by each athlete. In this context, we propose an instrumented evaluation to assess performance in Para-powerlifting. Our goal is to define and test a setup and a protocol to quantitatively assess the execution of bench press exercise in athletes with different abilities. Methods: We recruited an unimpaired athlete and three Paralympic athletes. They were requested to execute the bench press exercise while we recorded muscle activity and kinematic data from the upper body. We investigated the sport gesture by extracting parameters describing coordination, symmetry, and synchronism between arms, and motor variability while repeating the gesture. Results: Paralympic athletes performed the gestures with higher coordination between arms and low variability across repetitions compared to the unimpaired athlete, who was not at the Olympic level. All participants obtained similar kinematic performance by adopting different muscle strategies. Conclusions: This study is a proof of concept that the instrumented evaluation proposed here can allow to conduct a complete assessment of the bench press exercise, in terms of kinematics, muscle activity and performance in athletes with different abilities. [ABSTRACT FROM AUTHOR]

The notion of forbidden-transition graphs allows for a robust generalization of walks in graphs. In a forbidden-transition graph, every pair of edges incident to a common vertex is permitted or forbidden; a walk is compatible if all pairs of consecutive edges on the walk are permitted. Forbidden-transition graphs and related models have found applications in a variety of fields, such as routing in optical telecommunication networks, road networks, and bio-informatics. A widely-studied special case are edge-colored graphs, where a compatible walk is forbidden to take two edges of the same color in a row. We initiate the study of fundamental problems on finding paths, cycles and walks in forbidden-transition graphs from the point of view of parameterized complexity, including an in-depth study of tractability with regards to various graph-width parameters. Among several results, we prove that finding a simple compatible path between given endpoints in a forbidden-transition graph is W[1]-hard when parameterized by the vertex-deletion distance to a linear forest (so it is also hard when parameterized by pathwidth or treewidth). On the other hand, we show an algebraic trick that yields tractability when parameterized by treewidth for finding a compatible Hamiltonian cycle in the edge-colored graph setting. [ABSTRACT FROM AUTHOR]

POU genes are a family of evolutionarily conserved transcription factors with key functions in cell type specification and neurogenesis. In vitro experiments have indicated that the expression of some POU genes is controlled by the intercellular signaling molecule retinoic acid (RA). In this work, we aimed to characterize the roles of RA signaling in the regulation of POU genes in vivo. To do so, we studied POU genes during the development of the cephalochordate amphioxus, an animal model crucial for understanding the evolutionary origins of vertebrates. The expression patterns of amphioxus POU genes were assessed at different developmental stages by chromogenic in situ hybridization and hybridization chain reaction. Expression was further assessed in embryos subjected to pharmacological manipulation of endogenous RA signaling activity. In addition to a detailed description of the effects of these treatments on amphioxus POU gene expression, our survey included the first description of Pou2 and Pou6 expression in amphioxus embryos. We found that Pit-1, Pou2, Pou3l, and Pou6 expression are not affected by alterations of endogenous RA signaling levels. In contrast, our experiments indicated that Brn1/2/4 and Pou4 expression are regulated by RA signaling in the endoderm and the nerve cord, respectively. The effects of the treatments on Pou4 expression in the nerve cord revealed that, in developing amphioxus, RA signaling plays a dual role by (1) providing anteroposterior patterning information to neural cells and (2) specifying neural cell types. This finding is coherent with a terminal selector function of Pou4 for GABAergic neurons in amphioxus and represents the first description of RA-induced changes in POU gene expression in vivo. [ABSTRACT FROM AUTHOR]

Nicholas of Cusa (1401–1464) was not an uncritical supporter of papal authority. This essay recounts a nuanced understanding of his development by looking at a number of treatises and sermons focused on the reform of the pope as person and therefore of the reform of the papacy as institution. Cusanus believed the pope's authority was grounded in the faith and office of Peter and not personally in Peter's successor, who could therefore fairly be corrected. The successor to Peter was no more the rock than Peter as a human being had been. Consequently, Cusanus' recommendations for papal reform began with the personal reform of the pope as a faithful Christian first and not as a prelate. His critiques did not thereby threaten the papacy as an institution but, in fact, were intended to improve the man holding the see of Peter and in so doing to reform the office and its exercise. [ABSTRACT FROM AUTHOR]

Nicholas of Cusa (1401–1464) devoted Sermones 55 and 71 to considering the episode in Luke's Gospel on Mary having chosen the better part instead of her sister Martha (Luke 10. 38–42), though those sermons were preached on 15 August, the feast of the Virgin Mary's Assumption (1445–46). He also considered that episode within two other sermons: Sermon 5 on the feast of John the Baptist (24 June) and Sermon 8 for Mary's Assumption, both preached earlier in his career in 1431. This essay also engages Meister Eckhart's German Predigten 2 and 86. Eckhart (c. 1260–1328) broke with the conventional wisdom that Mary chose the better part by saying Martha enjoyed greater freedom and fulfilment than Mary because the older sister married prayer and service. Thus he offered an untraditional exegesis. While most patristic and medieval exegetes focused on the words good, better, best, or the vita mixta, Eckhart and Cusanus emphasized the action of choosing: the free human will of reviewing options and then choosing wisely from among a variety of paths. For Eckhart, it is Martha who chooses well. For Cusanus, it is her sister Mary. Though Eckhart likely had no Greek and Cusanus only some, their exegesis was more in line with the Koine tēn agathēn merida exelexato (τὴν ἀγαθὴν μϵρίδα ἐξϵλέξατο) than the Vulgate optimam partem eligit. [ABSTRACT FROM AUTHOR]

In this work, we propose a 3D fully convolutional architecture for video saliency prediction that employs hierarchical supervision on intermediate maps (referred to as conspicuity maps) generated using features extracted at different abstraction levels. We provide the base hierarchical learning mechanism with two techniques for domain adaptation and domain-specific learning. For the former, we encourage the model to unsupervisedly learn hierarchical general features using gradient reversal at multiple scales, to enhance generalization capabilities on datasets for which no annotations are provided during training. As for domain specialization, we employ domain-specific operations (namely, priors, smoothing and batch normalization) by specializing the learned features on individual datasets in order to maximize performance. The results of our experiments show that the proposed model yields state-of-the-art accuracy on supervised saliency prediction. When the base hierarchical model is empowered with domain-specific modules, performance improves, outperforming state-of-the-art models on three out of five metrics on the DHF1K benchmark and reaching the second-best results on the other two. When, instead, we test it in an unsupervised domain adaptation setting, by enabling hierarchical gradient reversal layers, we obtain performance comparable to supervised state-of-the-art. Source code, trained models and example outputs are publicly available at https://github.com/perceivelab/hd2s. [ABSTRACT FROM AUTHOR]

We construct an infinite family of counterexamples to Thomassen's conjecture that the vertices of every 3-connected, cubic graph on at least 8 vertices can be colored blue and red such that the blue subgraph has maximum degree at most 1 and the red subgraph minimum degree at least 1 and contains no path on 4 vertices. [ABSTRACT FROM AUTHOR]

A 2-edge-coloured graph G is supereulerian if G contains a spanning closed trail in which the edges alternate in colours. We show that for general 2-edge-coloured graphs it is NP-complete to decide whether the graph is supereulerian. An eulerian factor of a 2-edge-coloured graph is a collection of vertex-disjoint induced subgraphs which cover all the vertices of G such that each of these subgraphs is supereulerian. We give a polynomial algorithm to test whether a 2-edge-coloured graph has an eulerian factor and to produce one when it exists. A 2-edge-coloured graph is (trail-)colour-connected if it contains a pair of alternating (u, v)-paths ((u, v)-trails) whose union is an alternating closed walk for every pair of distinct vertices u, v. We prove that a 2-edge-coloured complete bipartite graph is supereulerian if and only if it is colour-connected and has an eulerian factor. A 2-edge-coloured graph is M-closed if xz is an edge of G whenever some vertex u is joined to both x and z by edges of the same colour. M-closed 2-edge-coloured graphs, introduced in Contreras-Balbuena et al. (Discret Math Theoret Comput Sci 21:1, 2019), form a rich generalization of 2-edge-coloured complete graphs. We show that if G is obtained from an M-closed 2-edge-coloured graph H by substituting independent sets for the vertices of H, then G is supereulerian if and only if G is trail-colour-connected and has an eulerian factor. Finally we discuss 2-edge-coloured complete multipartite graphs and show that such a graph may not be supereulerian even if it is trail-colour-connected and has an eulerian factor. [ABSTRACT FROM AUTHOR]

Little is known about the hormonal regulation of feline ovarian granulosa cell proliferation and steroidogenesis. The present study aimed to develop a hormone responsive granulosa cell culture system to measure steroidogenic and cell proliferation responses to help identify factors that might regulate ovarian function in queens. Five experiments were conducted each with 75 or more ovaries, three in spring and two in fall seasons. Granulosa cells were isolated and treated in vitro with various hormones in serum-free medium for 48 h after an initial 48 h plating in 10% fetal calf serum. In granulosa cells isolated from spring and fall collected feline ovaries, IGF1 alone and combined with FSH stimulated (P < 0.05) cell proliferation, whereas FSH alone had no effect (P > 0.10) on cell proliferation. Also, in granulosa cells collected in spring and fall, IGF1 alone and FSH alone increased (P < 0.05) estradiol production by severalfold, and a combination of FSH and IGF1 increased (P < 0.05) estradiol production above either FSH or IGF1 treatment alone. The FSH plus IGF1 treatment increased (P < 0.05) CYP19A1 mRNA abundance by 27-fold. In contrast, EGF decreased (P < 0.05) FSH plus IGF1-induced estradiol production by over 80% in granulosa cells of both spring and fall collected ovaries. In granulosa cells isolated from spring and fall collected ovaries, IGF1 plus FSH inhibited (P < 0.05) progesterone production. Melatonin increased (P < 0.05) FSH plus IGF1-induced cell proliferation and amplified (P < 0.05) the FSH plus IGF1-induced inhibition of progesterone production. However, melatonin and GH had no effect (P > 0.10) on estradiol production either alone or in combination with FSH plus IGF1 in both spring and fall. Prolactin, FGF9 and activin had no effect (P > 0.10) on cell proliferation or steroidogenesis. FGF2 decreased (P < 0.05) estradiol production without affecting progesterone production or cell numbers. Growth differentiation factor 9 (GDF9) increased (P < 0.05) progesterone production but had no effect (P > 0.10) on granulosa cell proliferation or estradiol production. In conclusion, the in vitro system described herewithin may be useful to assess and evaluate ovarian function in feline species and has identified EGF, FSH and IGF1 as major regulators of feline ovarian follicular function. • An in vitro cell culture system has been developed for feline granulosa cells. • Granulosa cell progesterone production was consistently inhibited by hormones. • Granulosa cell estradiol production was induced severalfold by specific hormones. • Epidermal growth factor consistently blocked estradiol production. [ABSTRACT FROM AUTHOR]

This paper studies the problem of proper‐walk connection number: given an undirected connected graph, our aim is to colour its edges with as few colours as possible so that there exists a properly coloured walk between every pair of vertices of the graph, that is, a walk that does not use consecutively two edges of the same colour. The problem was already solved on several classes of graphs but still open in the general case. We establish that the problem can always be solved in polynomial time in the size of the graph and we provide a characterization of the graphs that can be properly connected with k colours for every possible value of k. [ABSTRACT FROM AUTHOR]

DP‐coloring is a relatively new coloring concept by Dvořák and Postle and was introduced as an extension of list‐colorings of (undirected) graphs. It transforms the problem of finding a list‐coloring of a given graph G with a list‐assignment L to finding an independent transversal in an auxiliary graph with vertex set {(v,c)|v∈V(G),c∈L(v)}. In this paper, we extend the definition of DP‐colorings to digraphs using the approach from Neumann‐Lara where a coloring of a digraph is a coloring of the vertices such that the digraph does not contain any monochromatic directed cycle. Furthermore, we prove a Brooks' type theorem regarding the DP‐chromatic number, which extends various results on the (list‐)chromatic number of digraphs. [ABSTRACT FROM AUTHOR]

The weak 2-linkage problem for digraphs asks for a given digraph and vertices s 1 , s 2 , t 1 , t 2 whether D contains a pair of arc-disjoint paths P 1 , P 2 such that P i is an (s i , t i) -path. This problem is NP-complete for general digraphs but polynomially solvable for acyclic digraphs [8]. Recently it was shown [3] that if D is equipped with a weight function w on the arcs which satisfies that all edges have positive weight, then there is a polynomial algorithm for the variant of the weak-2-linkage problem when both paths have to be shortest paths in D. In this paper we consider the unit weight case and prove that for every pair of constants k 1 , k 2 , there is a polynomial algorithm which decides whether the input digraph D has a pair of arc-disjoint paths P 1 , P 2 such that P i is an (s i , t i) -path of length no more than d (s i , t i) + k i , for i = 1 , 2 , where d (s i , t i) denotes the length of the shortest (s i , t i) -path. We prove that, unless the exponential time hypothesis (ETH) fails, there is no polynomial algorithm for deciding the existence of a solution P 1 , P 2 to the weak 2-linkage problem where each path P i has length at most d (s i , t i) + c log 1 + ϵ ⁡ n for some constant c. [ABSTRACT FROM AUTHOR]

The maximal density of a measurable subset of R n avoiding Euclidean distance 1 is unknown except in the trivial case of dimension 1. In this paper, we consider the case of a distance associated to a polytope that tiles space, where it is likely that the sets avoiding distance 1 are of maximal density 2 - n , as conjectured by Bachoc and Robins. We prove that this is true for n = 2 , and for the Voronoi regions of the lattices A n , n ≥ 2 . [ABSTRACT FROM AUTHOR]

In recent years, there has been an exponential increase in the generation and accessibility of electronic healthcare data, often referred to as "real-world data". The landscape of data sources has significantly expanded to encompass traditional databases and newer sources such as the socialmedia, wearables, and mobile devices. Advances in information technology, along with the growth in computational power and the evolution of analytical methods relying on bioinformatic tools and/or artificial intelligence techniques, have enhanced the potential for utilizing this data to generate real-world evidence and improve clinical practice. Indeed, these innovative analytical approaches enable the screening and analysis of large amounts of data to rapidly generate evidence. As such numerous practical uses of artificial intelligence in medicine have been successfully investigated for image processing, disease diagnosis and prediction, as well as the management of pharmacological treatments, thus highlighting the need to educate health professionals on these emerging approaches. This narrative review provides an overview of the foremost opportunities and challenges presented by artificial intelligence in pharmacology, and specifically concerning the drug post-marketing safety evaluation. [ABSTRACT FROM AUTHOR]

Although numerous methods exist for the theoretical calculation of detonation parameters of explosives, few thermodynamic-hydrodynamic-based theoretical codes take into account particle size. The basis for their computational analysis is primarily focused on the equation of state of the detonation products, heat of formation, and density of the explosive composition. This study utilized regression analysis to model the relationship between the microstructure characteristics and detonation velocity of a heterogeneous high-explosive composition containing cyclotrimethylene-trinitrmaine (RDX). The principal characteristics examined were the average particle size of RDX, amount of HMX impurity within the RDX particles, method of RDX manufacture, and compositional density. Statistical analysis demonstrated the relevancy of the microstructure influence on the detonation velocity of the developed experimental compositions of 73 wt. % solids and 27 wt. % polyurethane binder. An equation is developed that accurately predicts detonation velocity based on average particle size, density, and manufacturing process for RDX. The model underscores the significance of the relationship between the average particle size and detonation velocity. Compositions containing smaller average particle sizes of RDX generate higher detonation velocities. A 100 micron increase in the average particle size was shown to decrease detonation velocity by 161 m/s for the monomodal polyurethane compositions used in this study. The relevance of using statistical models for selecting characteristics that result in optimum explosive performance is addressed. [ABSTRACT FROM AUTHOR]

This paper studies the problem of traffic monitoring which consists of differentiating a set of walks on a directed graph by placing sensors on as few arcs as possible. The problem of characterising a set of individuals by testing as few attributes as possible is already well-known, but traffic monitoring presents new challenges that the previous models of separation fall short from modelling such as taking into account the multiplicity and order of the arcs in a walk. We introduce a new and stronger model of separation based on languages that generalises the traffic monitoring problem. We study three subproblems with practical applications and develop methods to solve them by combining integer linear programming, separating codes and language theory. [ABSTRACT FROM AUTHOR]

The article focuses on the impact of hypertension on neuroinflammation in the hippocampus of rats and explores the potential protective effects of antioxidant and cholinergic cognitive-enhancing compounds, specifically CDP-Choline (CDP) and (+)-thioctic acid (TIO), on countering gliosis.

A new, insensitive nitroguanidyl functionalized nitrogen-rich material derived from 2,4-dinitrophenyl derivative was synthesized. N-2,4-dinitrophenyl-N1-nitroguanidine (DNP-NQ) has a crystal density of 1.74 g/cm3. The synthesis and properties of DNP-NQ are described. DNP-NQ was characterized by nuclear magnetic resonance (NMR), infrared spectroscopy, and gas pycnometry. Thermal properties were studied by differential scanning calorimetry (DSC). Results from small-scale sensitivity tests indicate that DNP-NQ is less sensitive than Cyclotrimethylenetrinitramine (RDX). DNP-NQ can be prepared in high yield. [ABSTRACT FROM AUTHOR]

Background: Real-world data on early treatment of coronavirus disease 2019 (COVID-19) outpatients with newly approved therapies are sparse. Aim: To explore the pattern of use of monoclonal antibodies (mAbs)/antiviral therapies approved for early COVID-19 treatment in non-hospitalized patients from England and Italy from December 2021 to October 2022. Methods: Public national dashboards on weekly mAb/antiviral use and/or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnoses from the Italian Medicines Agency, the Italian National Institute of Health, National Health Service in England and the UK Government were explored. Prevalence of antiviral use in outpatients during the entire study period and every two weeks was calculated, as a whole and by class and compounds. An interrupted time-series (ITS) analysis was carried out to assess the impact of predominant SARS-CoV-2 variants over time on the prevalence of use of mAbs/antivirals in England and Italy. Results: Overall, 77,469 and 195,604 doses of mAbs/antivirals were respectively administered to a total of 10,630,903 (7.3 per 1000) and 18,168,365 (10.8 per 1000) patients diagnosed with SARS-CoV-2 infection in England and Italy. Prevalence of use every two weeks increased from 0.07% to 3.1% in England and 0.9% to 2.3% in Italy during the study period. Regarding individual compounds, sotrovimab (prevalence of use, 1.6%) and nirmatrelvir/ritonavir (1.6%) in England, and nirmatrelvir/ritonavir (1.7%) and molnupiravir (0.5%) in Italy, reported the highest prevalence during a 2-week period. In the ITS analysis, the transition from Delta to Omicron variant predominance was associated with a significant increase in the use of sotrovimab, molnupiravir, remdesivir and nirmatrelvir/ritonavir in both England and Italy, with a reduction of other marketed mAbs. The extent of the increase was higher in England than in Italy for all these drugs except for nirmatrelvir/ritonavir. Conclusions: In this dual nationwide study, the prevalence of use of mAbs/antivirals against SARS-CoV-2 for early outpatients' treatment increased slowly up to 2.0–3.0% of all patients diagnosed with SARS-CoV-2 infection in both England and Italy from December 2021 to October 2022. The trend of individual drug use varied in relation to predominant SARS-CoV-2 variants with some differences across countries. In line with scientific societies' guidelines, nirmatrelvir/ritonavir was the most frequently prescribed antiviral in both countries in the most recent period. [ABSTRACT FROM AUTHOR]

Objective measures for evaluating active trunk movements and postural control in sitting are important for the assessment of people with Spinal Cord Injury (SCI) and for tailoring rehabilitative interventions. However, studies addressing this issue are limited [1]. This work fills this gap by proposing a modular protocol for the kinematic and muscular quantitative assessment of trunk control, specifically designed for SCI subjects. We used hunova® (Movendo Technology), a medical robotic device for the sensory-motor assessment and training of postural control in standing and sitting [2]. consisted of two different tests: a reaching (R) and an adaptive exercise (A), both performed while sitting on hunova®. The test R aims to assess the volitional component of trunk control: six reaching exercises, where subjects need to actively tilt the seat platform to move a cursor on the screen and reach targets, are alternating with two different platform inclinations: 3.5 and 5° (1° corresponds to 1 cm of cursor motion on the screen). The test A aims to assess how subjects adapt to predictable perturbations imposed by the seat platform [3]: six repetitions of an adaptive task, where subjects need to stabilize themselves while the seat platform moves following a given infinite-shape trajectory, is repeated once with eyes open (EO) and eyes close (EC), with different inclinations of the seat platform: 3, 5 and 7°. After testing the device and protocol on 18 healthy subjects, 10 SCI subjects (with different lesion level) participated in the study. Both the reaching block and the adaptive block (Fig. 1) started with the easiest testing condition and gradually increases the difficulty of the exercises. This allowed all SCI subjects, with different lesion level, to participate in the assessment. Electromyography (EMG) was recorded bilaterally from the following muscles: obliquus externus abdominis, trapezius descendens, trapezius transversalis, trapezius ascendens, erector spinae longissimus, erector spinae iliocostalis, multifidus, latissimus dorsi, soleus, tibialis anterior, vastus medialis, semitendinosus, gluteus medium. The leg muscles were recorded only for SCI subjects with an incomplete lesion of the spinal cord. For each subject, we characterized postural responses in terms of kinematics and muscular activity, estimating the correspondent spatiotemporal organization of the motoneuronal activity in the spinal cord [4]. All subjects with an incomplete SCI could finish the whole protocol. This was not the case for subjects with a complete lesion. Only one subject (lesion level D12) completed both blocks and had movement performance like SCI subjects with an incomplete lesion. The other subjects (two with lesion level D6 and one D3) performed few repetitions of R as they found difficult to control the seat platform, and the tasks with 3 and 5° of inclination for A. Concerning the performance, for R all subjects, independently on their type of lesion, reached a greater number of targets across repetitions. During A, all subjects had a bigger trunk sway for higher inclinations of the seat platform, with higher values in the repetitions with EC. Each SCI subject used his/her own muscular strategy for reaching the different targets and also for adapting to the seat motion, despite it was continuous and predictable. This assessment highlighted the differences in the muscular control among subjects, also due to the different lesions. This modular protocol evaluated in a quantitative, objective, repeatable, and comprehensive manner the kinematic and muscular strategies adopted by SCI subjects when performing dynamic tasks while sitting. The device hunova® allowed us to evaluate different aspects related to trunk control, the volitional and the feedforward control of balance while adapting to predictable and continuous perturbations. The results of this assessment will be used to tailor specific rehabilitative interventions. [ABSTRACT FROM AUTHOR]

End-effector robots for gait rehabilitation allow an intensive, controlled and repetitive training of the lower limbs. These devices assist the gait cycle by providing body weight support while applying mechanical forces directly to the user's feet. Several studies have shown how end-effector robots can improve gait kinematics, however little research has been conducted to investigate how the device might affect the gait muscle activation patterns of the user. Our aim was to investigate: (i) if the device induces different muscle patterns than those adopted during overground walking and (ii) whether and how different levels of assistance influence muscle patterns while walking with the device. 16 healthy volunteers walked 100 steps overground and with the support of an end-effector robotic device (GEO-system). In the latter case, participants were asked to walk while the device provided maximum, adaptive, and no bilateral assistance. During walking we recorded, using an electromyographic system (EMG), the activity of 8 muscles from each leg: tibialis anterior (TA), gastrocnemius medialis (GM), soleus (SOL), rectus femoris (RF), vastus medialis (VM), semitendinosus (ST), biceps femoris (BF), gluteus medius (GLM). At the same time, 2 Inertial Measurement Units (IMUs) were used to measure the angular velocity and angles of both feet. The gait cycle events were detected using the IMUs data and were used to segment the EMG signals. The latter were used to extract, with a non-negative matrix factorization algorithm [1], the muscle synergies - weights coefficients and activation profiles - of each walking condition. The same paradigm was also adopted to investigate the changes in muscle strategies during the ascent - descent of stairs. In the following, we will only describe and discuss the results of the overground walking task. Differences in the muscle activation patterns were observed between overground and end-effector assisted walking. When walking with the device, regardless of the assistance provided, the activity of the distal muscles (TA, SOL, GM) decreased, as well as the activity of most of the proximal muscles (GLM, ST, BF). No relevant differences were observed in muscle activations of the knee extensors (RF, VM), while changes in timing were observed in the muscle activations of the TAs, STs and BFs. In the end-effector assisted walking, the TAs were active only in the swing phase of the gait cycle, while the STs and BFs were active only in the stance phase of the gait cycle. Moreover, no differences in the muscle activation timings were observed when walking with the device in all assistive modalities. The only changes induced by the type of assistance were at the level of the STs and TAs. The activity of both muscles in the no assistance condition was higher than the maximum and adaptive assistance conditions. The 4 muscle synergies extracted for each walking condition confirmed these observations. In synergy 1, which is mainly described by ST, BF and TA, all the end-effector walking conditions appear to have a lower contribution of the ST and TA. In synergy 2 and 3, described respectively by the TA and the GLM, the weights during end-effector assisted walking are the same as those of the overground walking. In synergy 4, which is mainly described by the SOL and GM, the weights of both muscles in the end-effector walking conditions display a smaller contribution than in the overground walking condition. As expected, the activation profile of the muscle synergies in the end-effector and overground walking conditions appear to have different activations timings (see Table 1). The differences observed in the muscle patterns between end-effector assisted walking and overground walking appeared more influenced by the mechanical structure of the device than by the assistance provided. Specifically, the mechanical constrains due to anchoring the feet of the user to the platforms of the device and to the absence of a forward progression in space while walking may be the reasons behind the muscle patterns differences. [ABSTRACT FROM AUTHOR]

In the United States gender equality cases in front of the Supreme Court, State and Congressional legislation, and decisions by other United States courts have been decided by applying formal equality. This view of equality combined with the United States' "Negative Constitution" has led to extremely unjust gender equality rulings. At the same time, the increased influence of international human rights law means the United States can no longer ignore gender equality at home while preaching human rights abroad. Gender mainstreaming offers a way of looking at gender equality that would satisfy both international norms and the "Negative Constitution." [ABSTRACT FROM AUTHOR]

The synthesis, crystal structure and solid state properties of three different groups of magnetic organic–inorganic hybrid compounds are described and discussed. The reported examples are crystalline solids built from metal ions or metal clusters bonded to the organic moieties to form a single phase. The three families are: (a) perovskite metal halides, (b) electrical conductive radical-cation salts and (c) transition metal phosphonates and they differ by the type of chemical bonding between the organic and inorganic subnetworks. Organic–inorganic hybrid materials gained interest due to their potential applications in several fields and for their unusual collective electronic properties, such as magnetism, optical and electrical conductivity properties. Today they are experiencing a revival due to the discovery in some hybrids of coexistence of two physical properties such as ferroelectricity and magnetic order or ferromagnetism and metal-like electrical conductivity (dual-functional materials). The aim of this review is a survey of the crystal structure and properties of magnetic organic–inorganic hybrid compounds selected on the basis of their interesting electrical properties and for the potential applications. [ABSTRACT FROM AUTHOR]

The article explores the efforts of World Bank and other international development communities for women's education. Topics discussed include legal and institutional remedies to raise the girls' education; human rights and capabilities approach to the education; importance of primary education; and different cultural barriers to education such as employment discrimination and marriage expectations.

An essay is presented on linkages between the fall of Ancient Rome between the third and fifth centuries C.E. due to migrations by so-called barbarians and modern immigration debates in the U.S. The authors explore immigration to the U.S. from Mexico and security along the Mexico-U.S. border. Other topics include Spanish language in the U.S., the meaning of citizenship, and the language used to describe immigrants.

The new metal--organic compound nickel(II) 3,4;9,10-perylenediimide bis-phosphonate pentahydrate, i.e. Ni2[(PDI-BP)-(H20)2]-3H20 (1), has been synthesized and its structural and magnetic properties have been studied. Reaction of 3,4;9,10-perylenediimide bis-phosphonate (PDI-BP, hereafter) ligand and nickel chloride in water resulted in the precipitation of a red and poorly crystalline solid (1). As the solid shows a poor crystalline organization of aggregates, the energy dispersive X-ray diffraction analysis (EDXD) technique has been used to obtain short-range order structural information of the single nanoaggregates by radial distribution function analysis. The overall structure of the compound is characterized by layers containing perylene planes shifted in the direction perpendicular to the stacking axes in such a way that only the outer rings overlap. The edges of the perylene planes are connected to the phosphonate groups through an imido group. The oxygen atoms of the [--PO3]2 group and those of the water molecules are bonded to the nickel ions resulting in a [NiO6] octahedral coordination sphere. The Ni--O bond lengths are 0.21 ± 0.08 nm and the Ni--O--Ni angles of aligned moieties are 95 ± 2°. The oxygen atoms of the water molecules and the nickel atoms are nearly planar and almost perpendicular to the perylene planes forming chains of edge-sharing octahedra. Tlie magnetic properties of (1) show tlie presence of ¡ntiachain ferromagnetic Ni--Ni interactions and a long-range ferromagnetic order below 21 K with a canting angle and with a spin glasslike behavior due to disorder in the inorganic layer. Hysteresis cycles show a coercive field of ca. 272 mT at 2 K that decreases as the temperature is increased and vanishes at ca. 20 K. [ABSTRACT FROM AUTHOR]

We studied the surface and thermal properties of seven different varieties of cyclotrimethylene-trinitramine (RDX) crystalline explosives from five manufacturers using differential scanning calorimetry (DSC) and atomic force microscopy (AFM). The specific varieties of the RDX studied were acquired from the previous Reduced Sensitivity RDX Round Robin program. They were chosen because intensive characterization of the materials already existed including shock sensitivity and cyclotetramethylene-tetranitramine (HMX) impurity levels. AFM scans revealed a diversity of surface defects. To quantify the surface defects on the crystalline surface of the RDX particles, surface roughness measurements were acquired. Statistical analysis was undertaken to correlate the observed surface, HMX impurity levels, and DSC thermal curve properties with the known shock sensitivities of the material. It was determined that a statistically significant relationship exists between surface roughness and the shock sensitivity of the material while no relationship was observed between the DSC thermal properties and either surface roughness or shock sensitivity. The HMX content greatly affected the thermal properties of RDX but was uncorrelated with the shock sensitivity. [ABSTRACT FROM AUTHOR]

Light-blue crystals of chromium(II) methyl phosphonale dihydrate, [Cr(CH3PO3)(H2O)] · H2O, were obtained in wafer by mixing filtered solutions of methylphosphonic acid and chromium(II) chloride in the presence of urea in an inert atmosphere. The compound wax characterized by elemental analysis, TGA-DSC, X-ray crystallography, magnetic measurements, and UV-visible and FT-IR spectroscopies. The crystal and molecular structures (orthorhombic Pnma (no. 62): a=4.4714(5) Å, b=6.8762(7) Å, c= 19.180(2) Å, Z=4) have been solved using single-crystal X-ray diffraction. The chromium(II) ion is six-coordinated by oxygens (4 + 2) lo form an elongated octahedron, with the four equatorial oxygen atoms belonging to [-PO3]2- phosphonate groups. This stereochemistry of the Cr(II) ion (high-spin d4 electronic configuration) is ascribed to the Jahn-Teller effect. The [CrO6] chromophore, the [CH3PO3]2- anions, and the water molecules build a novel one-dimensional (1D) metal(II) oxide chain, anchored to each other within the ab plane by two oxygens of the phosphonate ligand. Within the chain, each Cr2+ ion is connected through double oxygen badges to its two neighbor, forming edge-sharing octahedra running along the b axis. The chains are further connected with the adjacent chains by phosphonate [-PO3]2- groups of the ligand, forming an inorganic layer that alternates along the c axis of the unit cell with bilayers, consisting of methyl groups and water of crystallization. The thermal variation of the magnetic susceptibility follows the Curie-Weiss law, with a large negative Weiss constant, θ = -60 K, indicating the presence of antiferromagnetic AF exchange interactions between neighboring Cr(II) ions. The magnetic behavior and the magnetic dimensionality have been analyzed in terms of Fishers classical limiting form of the Heisenberg chain theory, and a value of J= -9.3 cm-1 was found. The negative value of the infra-chain exchange constant coupling confirms the presence of an AF coupling. No sign of long-range magnetic ordering down to 2 K (the lowest measured temperature) is observed, in agreement with the predominant one-dimensional character of the exchange interactions. [ABSTRACT FROM AUTHOR]

Abstract: The surface of cyclotrimethylene-trinitramine (RDX), a commonly used crystalline explosive was studied using atomic force microscopy (AFM). A diversity of surface defects was observed in different RDX particles as well as different parts of the same particle. Statistical analysis was undertaken to model the observed surface characteristics with the known shock sensitivities of the material. To quantify the surface defects observed on the crystalline surface of the RDX particles, surface roughness measurements were acquired. It was determined that there exists a statistically significant relationship between surface roughness characteristics and the shock sensitivity of the material. [Copyright &y& Elsevier]

The article discusses the views of theologian Pierre d'Ailly on Saint Bernard of Cellier de Clairvaux, Dijon, France. He describes Bernard as a paragon not only of a supremely honorable man but of someone who could speak truth to power. In his sermon "Sermo de beato Bernardo," he describes Bernard as a model figure and not the caricaturish anti-intellectual erroneously been labeled. He states that Bernard is a man who teaches as much by the example of his life as by his words.

The reaction of nickel chloride with phenyl phosphonic acid under hydrothermal conditions resulted in the isolation of yellow-green single crystals of Ni[(C6H5PO3)(H2O). The structure of the compound has been solved by X-ray single-crystal diffraction studies. Ni[(C6H5PO3)(H2O)] crystallizes in the orthorhombic space group Pmn21 and is isostructural with the Mn(Il), Fe(ll), and Co(ll) analogues. It presents the typical features of the hybrid 2D structures, consisting of alternating inorganic and organic layers. The former are formed by six-coordinated nickel(ll) ions bridged by oxygen atoms into the layers. The inorganic layers are capped by the phenyl phosphonate groups, with phenyl groups of two adjacent ligands forming a hydrophobic bilayer region, and van der Waals contacts are established between them. The magnetic properties investigated by means of dc and ac susceptibility measurements point to an AF exchange coupling between nearest neighboring Ni(ll) ions. Below 5 K, the compound orders magnetically showing the typical features of a canted antiferromagnet. The magnetic behavior and magnetic dimensionality of Ni[(C6H5PO3)(H2O)] have been fully analyzed and compared to those of the Ni(II) parent compounds Ni[(RPO3)(H2O)] (where R = CH3, C18H37), which exhibit different symmetries of the inorganic layers and lengths of the R groups. [ABSTRACT FROM AUTHOR]

Abstract: The interaction between commercially available Single-Walled Carbon Nanotubes (SWNTs) and gaseous hydrazoic acid (HN3) was studied using attenuated total reflectance FTIR spectroscopy. Whether the HN3 gas reacts with SWNTs through physisorption or chemisorption was analyzed. This study shows that under ambient conditions gaseous HN3 reacted with the metal such as Ni or Fe present in the SWNTs to generate the corresponding metal azides. The data also suggest that the nanotube walls did not react to gaseous HN3 upon repeated exposures at ambient conditions. [Copyright &y& Elsevier]

Abstract: The crystal and magnetic structures of the hybrid organic–inorganic layer compound Fe[(CD3PO3)(D2O)] have been studied by neutron powder diffraction as a function of temperature down to 1.5K. The neutron diffraction pattern recorded at 200K shows that the fully deuterated compound crystallizes in one of the two known forms of the undeuterated Fe[(CH3PO3)(H2O)]. The crystal structure is orthorhombic, space group Pmn21, with the following unit-cell parameters: a=5.7095(1)Å, b=8.8053(3)Å and c=4.7987(1)Å; Z=2. The crystal structure remains unchanged on cooling from 200 to 1.5K. Moreover, at low temperature, Fe[(CD3PO3)(D2O)] shows a commensurate magnetic structure (k=(0,0,0)). As revealed by bulk susceptibility measurements on Fe[(CH3PO3)(H2O)], the magnetic structure corresponds to a canted antiferromagnet with a critical temperature T N=25K. Neutron powder diffraction reveals that below T N=23.5K the iron magnetic moments in Fe[(CD3PO3)(D2O)] are antiferromagnetically coupled and oriented along the b-axis, perpendicular to the inorganic layers. No ferromagnetic component is observable in the neutron powder diffraction experiment, due to its too small value (<0.1μ B). [Copyright &y& Elsevier]

Abstract: We review our recent work in the field of molecule-based magnets showing the structural and magnetic properties of a special class of hybrid organic–inorganic compounds, i.e. metal(II) organophosphonates. The synthesis, the crystal structures and, in particular, the magnetic studies of selected examples of compounds of formulas M(II)[(R–PO3)(H2O)], and M2[(O3P–R′–PO3)(2H2O)] M=Cr, Fe, Co; R=C n H2n+1, n =1, 2, 3… and C6H5, R′=(CH2)2 prepared in our laboratory are presented and discussed. Metal alkylphosphonates, except those of Co(II), are weak ferromagnets at low temperatures. The observed magnetic ordering temperature T N varies from 4.2 to 25K, depending on the transition metal ions and on crystal and molecular structure. Moreover, in the case of a bifunctional molecule like aminoethylphosphonic acid, NH2(CH2)2PO3H2, or the carboxyethylphosphonic acid, HO2C(CH2)2PO3H2, is used as a ligand, then a novel Cr(II) compound of formula Cr[NH3(CH2)2PO3(Cl)(H2O)] and a microporous Fe(III) salt (NH4)[Fe2(OH){O3P(CH2)2CO2}2] are isolated. The latter are both polar and, more interesting, Cr(II) ammoniumethylphosphonate chloride results to be a weak ferromagnet below T N =5.0K. [Copyright &y& Elsevier]

Abstract: A new Ni(II) layered hybrid organic-inorganic compound of formula Ni2[(NDI-BP)(H2O)2]·2H2O has been prepared in very mild conditions from N,N′-bis(2-phosphonoethyl)napthalene-1,4:5,8-tetracarboximide (NDI-BP ligand) and NiCl2. The X-ray powder structure characterization of the title compound suggests a pillared layered organic-inorganic hybrid structure. The distance between the organic and inorganic layers has been found to be 17.8Å. The inorganic layers consist of corner sharing [NiO5(H2O)] octahedra and they are pillared by the diphosphonate groups. DC and AC magnetic measurements as a function of temperature and field indicate the presence of 2D antiferromagnetic exchange interactions between the nearest-neighbor Ni(II) ions below 100K. A long-range magnetic ordering at T c∼21K has been established and is attributed to the presence of spin canting. AC magnetic measurements as a function of temperature at different frequencies confirm the occurrence of the magnetic ordering temperature at T=21K and the presence of a slight structural disorder in the title compound. [Copyright &y& Elsevier]

Abstract: Fe[(CH3(CH2)2PO3)(H2O)] (1) and Fe[(CH3(CH2)17PO3)(H2O)] (2) were synthesized by reaction of FeCl2·6H2O and the relevant phosphonic acid in water in presence of urea and under inert atmosphere. The compounds were characterized by elemental and thermogravimetric analyses, UV–visible and IR spectroscopy. The crystal structure of (1) was determined from X-ray single crystal diffraction studies at room temperature: monoclinic symmetry, space group P21, , , , and . The compound is lamellar and the structure is hybrid, made of alternating inorganic and organic layers along the c direction. The inorganic layers consist of Fe(II) ions octahedrally coordinated by five phosphonate oxygen atoms and one from the water molecule, separated by bi-layers of propyl groups. A preliminary structure characterization of compound (2) suggests a similar layered structure, but with an interlayer spacing of 40.3Å. The magnetic properties of the compounds were both studied by a dc and ac SQUID magnetometer. Fe[(CH3(CH2)2PO3)(H2O)] (1) obeys the Curie–Weiss law at temperatures above 50K (, ), indicating a Fe +II oxidation state, a high-spin d 6 () electronic configuration and an antiferromagnetic exchange couplings between the near-neighbouring Fe(II) ions. Below , Fe[(CH3(CH2)2PO3)(H2O)] exhibits a weak ferromagnetism. The critical temperature of has been determined by ac magnetic susceptibility measurements. Compound (2) shows the same paramagnetic behaviour of the iron (II) propyl derivative. The values of C and θ were found to be and −44K, respectively, thus suggesting the presence of Fe +II ion in the spin state and antiferromagnetic interactions between Fe(II) ions at low temperatures. Zero-field and field cooled magnetic susceptibility vs. T plots do not overlap below , suggesting the presence of an ordered magnetic state. The critical temperature, , has been located by the peaks at from the ac susceptibility (χ′and χ″) vs. T plots. Below hysteresis loops recorded in the temperature region show an S-shape, while below 15K assume an ellipsoid form. They reveal that compound (2) is a weak ferromagnet. The critical temperature in these layered Fe(II) alkylphosphonates is independent of the distance between the inorganic layers. [Copyright &y& Elsevier]

Abstract: Co[(CH3PO3)(H2O)] (1) and Co[(C2H5PO3)(H2O)] (2) were prepared by the hydrothermal method and isolated as blue-violet platelet crystals. They were characterized by X-ray diffraction, FT-IR, TGA-DSC techniques and their magnetic properties studied by a dc-SQUID magnetometer. Compound (1) shows an hybrid layered structure, made of alternating inorganic and organic layers along the a-direction of the unit cell. The inorganic layers contain Co(II) ions six-coordinated by five phosphonate oxygen atoms and one from the water molecule. These layers are separated by bi-layers of methyl groups and van der Waals contacts are established between them. In compound (2), the layered hybrid structure is rather similar to that described for compound (1), but the alternation of the inorganic and organic layers is along the b-direction of the unit cell. The magnetic behavior of (1) and (2) as function of temperature and magnetic field was studied. The compounds obey the Curie–Weiss law at temperatures above 100K, the Curie C, and Weiss θ constants for the methyl derivative being and and for the ethyl derivative and , respectively. The observed magnetic moments for Co atom at room temperature (i.e. and 5.38 BM, respectively) are higher than those expected for a spin-only value for high spin Co(II) (), revealing a substantial orbital contribution to the magnetic moment. The negative values of θ are an indication of the presence of antiferromagnetic exchange couplings between the near-neighbors Co(II) ions, within the layers. [Co(C n H2 n +1PO3)(H2O)] () are 2D Ising antiferromagnets at low temperatures. [Copyright &y& Elsevier]