Complexity-functioning relationships differ across different environmental conditions.

Habitat complexity is widely considered an important determinant of biodiversity, and enhancing complexity can play a key role in restoring degraded habitats. However, the effects of habitat complexity on ecosystem functioning - as opposed to biodiversity and community structure - are relatively poorly understood for artificial habitats, which dominate many coastlines. With Greening of Grey Infrastructure (GGI) approaches, or eco-engineering, increasingly being applied around the globe, it is important to understand the effects that modifying habitat complexity has on both biodiversity and ecological functioning in these highly modified habitats. We assessed how manipulating physical (primary substrate) and/or biogenic habitat (bivalves) complexity on intertidal artificial substrata affected filtration rates, net and gross primary productivity (NPP and GPP, respectively) and community respiration (CR) - as well as abundance of filter feeders and macro-algae and habitat use by cryptobenthic fish across six locations in three continents. We manipulated both physical and biogenic complexity using 1) flat or ridged (2.5 cm or 5 cm) settlement tiles that were either 2) unseeded or seeded with oysters or mussels. Across all locations, increasing physical and biogenic complexity (5 cm seeded tiles) had a significant effect on most ecological functioning variables, increasing overall filtration rates and community respiration of the assemblages on tiles but decreasing productivity (both GPP and NPP) across all locations. There were no overall effects of increasing either type of habitat complexity on cryptobenthic fish MaxN, total time in frame or macro-algal cover. Within each location, there were marked differences in the effects of habitat complexity. In Hobart, we found higher filtration, filter feeder biomass and community respiration on 5 cm tiles compared to flat tiles. However, at this location, both macro-algae cover and GPP decreased with increasing physical complexity. Similarly in Dublin, filtration, filter feeder biomass and community respiration were higher on 5 cm tiles compared to less complex tiles. In Sydney, filtration and filter feeder biomass were higher on seeded than unseeded tiles, and fish MaxN was higher on 5 cm tiles compared to flat tiles. On unseeded tiles in Sydney, filter feeder biomass also increased with increasing physical complexity. Our findings suggest that GGI solutions via increased habitat complexity are likely to have trade-offs among potentially desired functions, such as productivity and filtration rates, and variable effects on cryptobenthic fish communities. Importantly, our results show that the effects of GGI practices can vary markedly according to the environmental context and therefore should not be blindly and uniformly applied across the globe.

Genome assembly of the bearded iris, Iris pallida Lam.

Irises are perennial plants, representing a large genus with hundreds of species. While cultivated extensively for their ornamental value, commercial interest in irises lies in the secondary metabolites present in their rhizomes. The Dalmatian Iris (Iris pallida Lam.) is an ornamental plant that also produces secondary metabolites with potential value to the fragrance and pharmaceutical industries. In addition to providing base notes for the fragrance industry, iris tissues and extracts possess antioxidant, anti-inflammatory and immunomodulatory effects. However, study of these secondary metabolites has been hampered by a lack of genomic information, requiring difficult extraction and analysis techniques. Here, we report the genome sequence of Iris pallida Lam., generated with Pacific Bioscience long-read sequencing, resulting in a 10.04-Gbp assembly with a scaffold N50 of 14.34 Mbp and 91.8% complete BUSCOs. This reference genome will allow researchers to study the biosynthesis of these secondary metabolites in much greater detail, opening new avenues of investigation for drug discovery and fragrance formulations.

Structural dynamics of a thermally silent triiron(II) spin crossover defect grid complex.

The structural evolution of spin crossover (SCO) complexes during their spin transition at equilibrium and out-of-equilibrium conditions needs to be understood to enable their successful utilisation in displays, actuators and memory components. In this study, diffraction techniques were employed to study the structural changes accompanying the temperature increase and the light irradiation of a defect [2 × 2] triiron(II) metallogrid of the form [FeII3LH2(HLH)2](BF4)4·4MeCN (FE3), LH = 3,5-bis{6-(2,2'-bipyridyl)}pyrazole. Although a multi-temperature crystallographic investigation on single crystals evidenced that the compound does not exhibit a thermal spin transition, the structural analysis of the defect grid suggests that the flexibility of the grid, provided by a metal-devoid vertex, leads to interesting characteristics that can be used for intermolecular cooperativity in related thermally responsive systems. Time-resolved photocrystallography results reveal that upon excitation with a ps laser pulse, the defect grid shows the first two steps of the out-of-equilibrium process, namely the photoinduced and elastic steps, occurring at the ps and ns time scales, respectively. Similar to a previously reported [2 × 2] tetrairon(II) metallogrid, FE3 exhibits a local distortion of the entire grid during the photoinduced step and a long-range distortion of the lattice during the elastic step. Although the lifetime of the pure photoinduced high spin (HS) state is longer in the tetranuclear grid than in the defect grid, suggesting that the global nuclearity plays a crucial role for the lifetime of the photoinduced species, the influence of the co-crystalising solvent on the lifetime of the photoinduced HS state remains unknown. This study sheds light on the out-of-equilibrium dynamics of a thermally silent defect triiron SCO metallogrid.

Interventions to improve outcomes for caregivers of patients with advanced cancer: a meta-analysis.

BACKGROUND: Family caregivers of patients with advanced cancer often have poor quality of life (QOL) and mental health. We examined the effectiveness of interventions offering support for caregivers of patients with advanced cancer on caregiver QOL and mental health outcomes. METHODS: We searched Ovid MEDLINE, EMBASE, Cochrane CENTRAL, and Cumulative Index to Nursing and Allied Health Literature databases from inception through June 2021. Eligible studies reported on randomized controlled trials for adult caregivers of adult patients with advanced cancer. Meta-analysis was conducted for primary outcomes of QOL, physical well-being, mental well-being, anxiety, and depression, from baseline to follow-up of 1-3 months; secondary endpoints were these outcomes at 4-6 months and additional caregiver burden, self-efficacy, family functioning, and bereavement outcomes. Random effects models were used to generate summary standardized mean differences (SMD). RESULTS: Of 12 193 references identified, 56 articles reporting on 49 trials involving 8554 caregivers were eligible for analysis; 16 (33%) targeted caregivers, 19 (39%) patient-caregiver dyads, and 14 (29%) patients and their families. At 1- to 3-month follow-up, interventions had a statistically significant effect on overall QOL (SMD = 0.24, 95% confidence interval [CI] = 0.10 to 0.39); I2 = 52.0%), mental well-being (SMD = 0.14, 95% CI = 0.02 to 0.25; I2 = 0.0%), anxiety (SMD = 0.27, 95% CI = 0.06 to 0.49; I2 = 74.0%), and depression (SMD = 0.34, 95% CI = 0.16 to 0.52; I2 = 64.4) compared with standard care. In narrative synthesis, interventions demonstrated improvements in caregiver self-efficacy and grief. CONCLUSIONS: Interventions targeting caregivers, dyads, or patients and families led to improvements in caregiver QOL and mental health. These data support the routine provision of interventions to improve well-being in caregivers of patients with advanced cancer.

Short- vs. long-range elastic distortion: structural dynamics of a [2 × 2] tetrairon(II) spin crossover grid complex observed by time-resolved X-Ray crystallography.

Spin crossover complexes (SCO) are among the most studied molecular switches due to their potential use in displays, sensors, actuators and memory components. A prerequisite to using these materials is the understanding of the structural changes following the spin transition at out-of-equilibrium conditions. So far, out-of-equilibrium studies in SCO solids have been focused on mononuclear complexes, though a growing number of oligonuclear SCO complexes showing cooperative effects are being reported. Here, we use time-resolved pink Laue crystallography to study the out-of-equilibrium dynamics of a [2 × 2] tetranuclear metallogrid of the form [FeII4LMe4](BF4)4·2MeCN ([LMe]- = 4-methyl-3,5-bis{6-(2,2'-bipyridyl)}pyrazolate). The out-of-equilibrium spin state switching induced by a ps laser pulse demonstrates that the metallogrid exhibits a multi-step response similar to that reported for mononuclear complexes. Contrary to the mononuclear complexes, the metallogrid shows two types of elastic distortions at different time scales. The first is a short-range distortion that propagates over the entire Fe4 grid complex during the ps time scale, and it is caused by the rearrangement of the coordination sphere of the photo-switching ion and the constant feedback between strongly linked metal ions. The second is a long-range distortion caused by the anisotropic expansion of the lattice during the ns time scale, observed in mononuclear materials. The structural analysis demonstrates that the long-range prevails over the short-range distortion, inducing the largest deformation of both the entire grid and the coordination sphere of each metal ion. The present study sheds light on the out-of -equilibrium dynamics of a non-cooperative oligonuclear complex.

Public interest in medical assistance in dying and palliative care.

OBJECTIVES: Medical assistance in dying (MAiD) is legal in an increasing number of countries, but there are concerns that its availability may compromise access to palliative care. We assessed public interest in MAiD, palliative care, both, or neither, and examined characteristics associated with this interest. METHODS: We surveyed a representative sample of the adult Canadian public, accessed through a panel from May to June 2019. Weighted generalised multinomial logistic regression analyses were used to determine characteristics associated with interest in referral to palliative care, MAiD, or both, in the event of diagnosis with a serious illness. RESULTS: Of 1362 participants who had heard of palliative care, 611 (44.8% weighted (95% CI 42.1% to 47.5%)) would be interested in both MAiD and palliative care, 322 (23.9% (95% CI 21.5% to 26.2%)) palliative care alone, 171 (12.3% (95% CI 10.5% to 14.1%)) MAiD alone and 258 (19.0% (95% CI 16.9% to 21.2%)) neither. In weighted multinomial logistic regression analyses, interest in both MAiD and palliative care (compared with neither) was associated with better knowledge of the definition of palliative care, older age, female gender, higher education and less religiosity; interest in palliative care alone was associated with better knowledge of the definition of palliative care, older age, female gender and being married/common law; interest in MAiD alone was associated with less religiosity (all p<0.05). CONCLUSIONS: There is substantial public interest in potential referral to both MAiD and palliative care. Simultaneous availability of palliative care should be ensured in jurisdictions where MAiD is legal, and education about palliative care should be a public health priority.

Medication adverse events in the ambulatory setting: A mixed-methods analysis.

PURPOSE: To characterize ambulatory care adverse drug events reported to the Collaborative Healthcare Patient Safety Organization (CHPSO), a network of 400 hospitals across the United States, and identify addressable contributing factors. METHODS: We abstracted deidentified ambulatory care CHPSO reports compiled from May 2012 to October 2018 that included medication-related adverse events to identify implicated medications and contributing factors. We dual-coded 20% of the sample. We quantitatively calculated co-occurring frequent item sets of contributing factors and then applied a qualitative thematic analysis of co-occurring sets of contributing factors for each drug class using an inductive analytic approach to develop formal themes. RESULTS: Of 1,244 events in the sample, 208 were medication related. The most commonly implicated medication classes were anticoagulants (n = 97, or 46% of events), antibiotics (n = 24, 11%), hypoglycemics (n = 19, 9%), and opioids (n = 17, 8%). For anticoagulants, timely follow-up on supratherapeutic international normalized ratio (INR) values occurred before the development of symptoms. Incident reports citing antibiotics often described prescribing errors and failure to review clinical contraindications. Reports citing hypoglycemic drugs described low blood sugar events due to a lack of patient education or communication. Reports citing opioids described drug-drug interactions, commonly involving benzodiazepines. CONCLUSION: Ambulatory care prescribing clinicians and community pharmacists have the potential to mitigate harm related to anticoagulants, antibiotics, hypoglycemics, and opioids. Recommendations include increased follow-up for subtherapeutic INRs, improved medical record integration and chart review for antibiotic prescriptions, enhanced patient education regarding hypoglycemics, and alerts to dissuade coprescription of opioids and benzodiazepines.

Crucial Convolution: Genetic and Molecular Mechanisms of Coiling during Epididymis Formation and Development in Embryogenesis.

As embryonic development proceeds, numerous organs need to coil, bend or fold in order to establish their final shape. Generally, this occurs so as to maximise the surface area for absorption or secretory functions (e.g., in the small and large intestines, kidney or epididymis); however, mechanisms of bending and shaping also occur in other structures, notably the midbrain-hindbrain boundary in some teleost fish models such as zebrafish. In this review, we will examine known genetic and molecular factors that operate to pattern complex, coiled structures, with a primary focus on the epididymis as an excellent model organ to examine coiling. We will also discuss genetic mechanisms involving coiling in the seminiferous tubules and intestine to establish the final form and function of these coiled structures in the mature organism.

Metal-to-metal communication during the spin state transition of a [2 × 2] Fe(II) metallogrid at equilibrium and out-of-equilibrium conditions.

Spin crossover (SCO) complexes are prototypes of materials with bi- or multi-stability in the solid state. The structural evolution during their spin transition is a key feature to establish the foundations of how to utilize this type of material. So far, ultrafast time-resolved structural investigations of SCO solids have been focused on monometallic complexes, though an increasing number of oligometallic SCO complexes showing cooperativity effects are being reported. Here, we used single crystal X-ray crystallography and time-resolved pink Laue photocrystallography to study the molecular reorganisation during the thermal and photoinduced SCO of a [2 × 2] tetranuclear metallogrid of the form [FeII4LMe4](BF4)4·2MeCN ([LMe]- = 4-methyl-3,5-bis{6-(2,2'-bipyridyl)}pyrazolate). A multitemperature crystallographic investigation on single crystals reveals an effective communication between the metal centres during thermal SCO, observed by the simultaneous transformation of the coordination polyhedra of both crystallographic-symmetry independent metal atoms accompanying the SCO in only one of them. Time-resolved photocrystallography results reveal the different molecular responses between mononuclear and oligonuclear complexes, after light irradiation with a picosecond laser pulse. While mononuclear SCO complexes reorganise once during the first nanosecond after excitation, the tetranuclear metallogrid exhibits a multiple structural rearrangement in the same span of time. Such behaviour is attributed to the elastic communication between metal atoms, which allows the propagation of a short-range elastic distortion over the entire Fe4 grid complex. The present study sheds light on the importance of strong elastic coupling of metal atoms during the correlated spin transition of oligometallic complexes.

Public knowledge and attitudes concerning palliative care.

OBJECTIVE: WHO recommends early integration of palliative care alongside usual care to improve quality of life, although misunderstanding of palliative care may impede this. We compared the public's perceived and actual knowledge of palliative care, and examined the relationship of this knowledge to attitudes concerning palliative care. METHODS: We analysed data from a survey of a representative sample of the Canadian public, accessed through a survey panel in May-June 2019. We compared high perceived knowledge ('know what palliative care is and could explain it') with actual knowledge of the WHO definition (knew ≥5/8 components, including that palliative care can be provided early in the illness and together with life-prolonging treatments), and examined their associations with attitudes to palliative care. RESULTS: Of 1518 adult participants residing in Canada, 45% had high perceived knowledge, of whom 46% had high actual knowledge. Participants with high (vs low) perceived knowledge were more likely to associate palliative care with end-of-life care (adjusted OR 2.15 (95% CI 1.66 to 2.79), p<0.0001) and less likely to believe it offered hope (0.62 (95% CI 0.47 to 0.81), p=0.0004). Conversely, participants with high (vs low) actual knowledge were less likely to find palliative care fearful (0.67 (95% CI 0.52 to 0.86), p=0.002) or depressing (0.72 (95% CI 0.56 to 0.93), p=0.01) and more likely to believe it offered hope (1.88 (95% CI 1.46 to 2.43), p<0.0001). CONCLUSIONS: Stigma regarding palliative care may be perpetuated by those who falsely believe they understand its meaning. Public health education is needed to increase knowledge about palliative care, promote its early integration and counter false assumptions.

Deliberations on Natural Products and Future Directions in the Pharmaceutical Industry.

Natural Products (NPs) are molecular' special equipment ' that impart survival benefits on their producers in nature. Due to their evolved functions to modulate biology these privileged metabolites are substantially represented in the drug market and are continuing to contribute to the discovery of innovative medicines such as the recently approved semi-synthetic derivative of the bacterial alkaloid staurosporin in oncology indications. The innovation of low molecular weight compounds in modern drug discovery is built on rapid progress in chemical, molecular biological, pharmacological and data sciences, which together provide a rich understanding of disease-driving molecular interactions and how to modulate them. NPs investigated in these pharmaceutical research areas create new perspectives on their chemical and biological features and thereby new chances to advance medical research. New methods in analytical chemistry linked with searchable NP-databases solved the issue of reisolation and enabled targeted and efficient access to novel molecules from nature. Cheminformatics delivers high resolution descriptions of NPs and explores the substructures that systematically map NP-chemical space by sp³-enriched fragments. Whole genome sequencing has revealed the existence of collocated gene clusters that form larger functional entities together with proximate resistance factors thus avoiding self-inhibition of the encoded metabolites. The analysis of bacterial and fungal genes provides tantalizing glimpses of new compound-target pairs of therapeutic value. Furthermore, a dedicated investigation of structurally unique, selectively active NPs in chemical biology demonstrates their extraordinary power as shuttles between new biological target spaces of pharmaceutical relevance.

Effect of Pleomorphic Adenoma Gene 1 Deficiency on Selected Behaviours in Adult Mice.

The proto-oncogene pleomorphic adenoma gene 1 (Plag1) encodes a zinc finger transcription factor. PLAG1 is part of the high motility group AT hook-2 (HGMA2)-PLAG1-insulin-like growth factor 2 (IGF2) pathway that, when disrupted, leads to Silver-Russell syndrome, a severe form of intrauterine growth restriction. With little known about PLAG1's role in normal physiology, this study is the first to characterise the behavioural phenotype of PLAG1-deficient mice. Mice were tested for differences in circadian locomotor activity and body temperature, sleep-like behaviour, anxiety-like behaviour, cognition, social behaviour, and sensorimotor gating. Overall, the behavioural phenotype of the Plag1 knock-out (KO) mice was mild: no significant differences were seen in circadian activity levels, locomotion, object recognition, spatial memory or sociability compared to wild-type mice. However, the cued test of fear conditioning, prepulse inhibition of the startle response and Preyer's reflex test suggest that Plag1 KO mice may have a hearing impairment. This implies that PLAG1 plays an important role in proper functioning and/or development of the neural circuitry behind the auditory processes or interacts with genes involved in those processes.

Transcriptome analysis of the epididymis from Plag1 deficient mice suggests dysregulation of sperm maturation and extracellular matrix genes.

BACKGROUND: The transcription factor pleomorphic adenoma gene 1 (PLAG1) is required for male fertility. Mice deficient in PLAG1 exhibit decreased sperm motility and abnormal epididymal tubule elongation and coiling, indicating impaired sperm maturation during epididymal transit. However, the downstream transcriptomic profile of the Plag1 knockout (KO; Plag1-/- ) murine epididymis is currently unknown. RESULTS: In this study, the PLAG1-dependent epididymal transcriptome was characterised using RNA sequencing. Several genes important for the control of sperm maturation, motility, capacitation and the acrosome reaction were dysregulated in Plag1-/- mice. Surprisingly, several cell proliferation genes were upregulated, and Ki67 analysis indicated that cell proliferation is aberrantly upregulated in the cauda epididymis stroma of Plag1-/- mice. Gene ontology analysis showed an overall upregulation of genes encoding extracellular matrix components, and an overall downregulation of genes encoding metalloendopeptidases in the epididymides from Plag1-/- mice. CONCLUSION: Together, these results suggest a defect in the epididymal extracellular matrix in Plag1-/- mice. These results imply that in addition to maintaining epididymal integrity directly, PLAG1 may also regulate several genes involved in the regulation of sperm maturation and capacitation. Moreover, PLAG1 may also be involved in regulating tissue homeostasis and ensuring proper structure and maintenance of the extracellular matrix in the epididymis.

Exploring the light-induced dynamics in solvated metallogrid complexes with femtosecond pulses across the electromagnetic spectrum.

Oligonuclear complexes of d4-d7 transition metal ion centers that undergo spin-switching have long been developed for their practical role in molecular electronics. Recently, they also have appeared as promising photochemical reactants demonstrating improved stability. However, the lack of knowledge about their photophysical properties in the solution phase compared to mononuclear complexes is currently hampering their inclusion into advanced light-driven reactions. In the present study, the ultrafast photoinduced dynamics in a solvated [2 × 2] iron(II) metallogrid complex are characterized by combining measurements with transient optical-infrared absorption and x-ray emission spectroscopy on the femtosecond time scale. The analysis is supported by density functional theory calculations. The photocycle can be described in terms of intra-site transitions, where the FeII centers in the low-spin state are independently photoexcited. The Franck-Condon state decays via the formation of a vibrationally hot high-spin (HS) state that displays coherent behavior within a few picoseconds and thermalizes within tens of picoseconds to yield a metastable HS state living for several hundreds of nanoseconds. Systematic comparison with the closely related mononuclear complex [Fe(terpy)2]2+ reveals that nuclearity has a profound impact on the photoinduced dynamics. More generally, this work provides guidelines for expanding the integration of oligonuclear complexes into new photoconversion schemes that may be triggered by ultrafast spin-switching.

Revealing Hot and Long-Lived Metastable Spin States in the Photoinduced Switching of Solvated Metallogrid Complexes with Femtosecond Optical and X-ray Spectroscopies.

An atomistic understanding of the photoinduced spin-state switching (PSS) within polynuclear systems of d4-d7 transition metal ion complexes is required for their rational integration into light-driven reactions of chemical and biological interest. However, in contrast to mononuclear systems, the multidimensional dynamics of the PSS in solvated molecular arrays have not yet been elucidated due to the expected complications associated with the connectivity between the metal centers and the strong interactions with the surroundings. In this work, the PSS in a solvated triiron(II) metallogrid complex is characterized using transient optical absorption and X-ray emission spectroscopies on the femtosecond time scale. The complementary measurements reveal the photoinduced creation of energy-rich (hot) and long-lived quintet states, whose dynamics differ critically from their mononuclear congeners. This finding opens major prospects for developing novel schemes in solution-phase spin chemistry that are driven by the dynamic PSS process in compact oligometallic arrays.

Evolving Definitions of Palliative Care: Upstream Migration or Confusion?

OPINION STATEMENT: Palliative care has evolved over the decades from its roots in the hospice movement to a much wider approach in which early intervention further "upstream" in the illness is encouraged to improve quality of life for patients and their families. This new definition has a strong evidence base in cancer trials and is supported by major national and international organizations. However, it has proven difficult to convince patients, the public, and even healthcare providers, of this upstream migration of palliative care, with many continuing to associate palliative care exclusively with end-of-life care. A multitude of definitions now exists, with varying emphasis on early intervention versus end-of-life care. In addition, a new nomenclature has emerged to conceal the end-of-life component of palliative care despite its continued importance, adding further to the confusion. Uncertainty within the specialty about the definition of palliative care will not reassure referring physicians and policymakers about its meaning nor convince them of its importance. Accuracy and clarity in the form of an established definition of palliative care are required to reduce misconceptions, facilitate clinical and academic development, and promote effective communication. This definition should acknowledge both expertise in end-of-life care and its relevance for improving outcomes early in the course of advanced cancer, and should be disseminated widely and practiced consistently.

Deficiency of the transcription factor PLAG1 results in aberrant coiling and morphology of the epididymis.

Mice deficient in the transcription factor pleomorphic adenoma gene 1 (PLAG1) exhibit reproductive issues that are characterized, in part, by decreased progressive sperm motility in the male. However, the underlying cause of this impairment is unknown. As epididymal transit is critical for sperm maturation and motility, the morphology of the epididymis of Plag1-deficient mice was investigated and the spatial expression patterns of PLAG1 protein and mRNA were identified. Using X-gal staining and in situ hybridization, PLAG1 was shown to be widely expressed in both the epithelium and stroma in all regions of the mouse epididymis. Interestingly, the X-gal staining pattern was markedly different in the cauda, where it could be suggestive of PLAG1 secretion into the epididymal lumen. At all ages investigated, the morphology of epididymides from Plag1 knockout (KO) mice was aberrant; the tubule failed to elongate and coil, particularly in the corpus and cauda, and the cauda was malformed, lacking its usual bulbous shape. Moreover, the epididymides from Plag1 KO mice were significantly reduced in size relative to body weight. In 20% of Plag1-deficient mice, the left testicle and epididymis were lacking. The impaired morphogenesis of the epididymal tubule is likely to be a major contributing factor to the fertility problems observed in male Plag1-deficient mice. These results also establish PLAG1 as an important regulator of male reproduction, not only through its involvement in testicular sperm production, but also via its role in the development and function of the epididymis.

Is polypharmacy an increasing burden in chronic kidney disease? The German experience.

This is a commentary article describing the key findings of the German chronic kidney disease (GCKD) study and how these relate to current practice. With the GCKD study showing high levels of polypharmacy, this article discusses ways to ensure that polypharmacy is appropriate and the difficulties faced within a chronic kidney disease population. Suggestions of ways to minimize medication burden in renal patients provide some practical advice for clinicians.

Heterometallic Ru2Co2 [2 × 2] Grid with Localized Single Molecule Magnet Behavior.

Metal complexes with a [n × n] gridlike structure are discussed as attractive building blocks for various materials chemistry applications in molecular nanotechnology and electronics, which often rely on the grids' magnetic and redox properties. Most of the known metallogrids are homometallic, though heterometallic systems that comprise two or more different metals promise higher level functionalities. However, heterometallic [n × n] grids are relatively rare, mostly because of the more challenging synthetic strategies. To that end a new heterometallic [2 × 2] grid complex [L4Ru2Co2](BF4)4 (2) based on a known pyrazolate-bridged bis(tridentate) compartmental N-donor ligand [L]- is presented in this work, along with its doubly oxidized congener [L4Ru2Co2](BF4)6 (3). In order to prevent scrambling of the different metal ions, a stepwise synthetic approach was implemented in which an inert RuII "corner complex" [(HL)2Ru](BF4)2 (1) was isolated first, followed by addition of the more labile CoII. This exclusively yields the desired [L4Ru2Co2]4+ with anti-topology, viz., with the RuII and CoII ions situated at opposite corners of the [2 × 2] grid, as confirmed by single crystal X-ray diffraction. 2 can be sequentially oxidized four times, first at the Co vertices and then at the Ru vertices. 1H NMR spectroscopy as well as ESI mass spectrometry evidenced integrity of the [L4Ru2Co2]4+/6+ grids in solution. Structural and magnetic analyses revealed that paramagnetic 2 features LS-RuII and HS-CoII ions (LS = low-spin, HS = high-spin) whereas LS-RuII and LS-CoIII ions are present in diamagnetic 3. The LS-RuII ions in 2 serve to magnetically isolate the HS-CoII whose coordination geometry is strongly distorted from octahedral. A large and negative axial zero-field splitting value (D = -64 cm-1) for the local S = 3/2 ions is shown to lead to single molecule magnetic (SMM) properties characterized by a barrier to spin inversion of Ueff = 8.8 cm-1 and a single relaxation process with τo = 3.1 × 10-5 s. Transition metal [2 × 2] grid complexes showing SMM behavior are extremely rare, and this is the first heterometallic 3d/4d grid system featuring such a magnetic signature.

Rapid neuroinflammatory changes in human acute intracerebral hemorrhage.

OBJECTIVE: Spontaneous intracerebral hemorrhage (ICH) is the commonest form of hemorrhagic stroke and is associated with a poor prognosis. Neurosurgical removal of intracerebral hematoma has limited benefit and no pharmacotherapies are available. In acute ICH, primary tissue damage is followed by secondary pathology, where the cellular and neuroinflammatory changes are poorly understood. METHODS: We studied histological changes in postmortem tissue from a cohort of spontaneous supra-tentorial primary ICH cases (n = 27) with survival of 1-12 days, compared to a matched control group (n = 16) examined in corresponding regions. Hematoxylin-eosin and microglial (Iba1) immunolabelled sections were assessed at 0-2, 3-5, and 7-12 days post-ICH. RESULTS: Peri-hematoma, the observed ICH-related changes include edema, tissue neutrophils and macrophages from day 1. Ischemic neurons and swollen endothelial cells were common at day 1 and universal after day 5, as were intramural erythrocytes within small vessel walls. Activated microglia were evident at day 1 post-ICH. There was a significant increase in Iba1 positive area fraction at 0-2 (threefold), 3-5 (fourfold), and 7-12 days post ICH (ninefold) relative to controls. Giant microglia were detected peri-hematoma from day 5 and consistently 7-12 days post-ICH. INTERPRETATION: Our data indicate that neuroinflammatory processes commence from day 1 post-ICH with changing microglial size and morphology following ICH and up to day 12. From day 5 some microglia exhibit a novel multiply nucleated morphology, which may be related to changing phagocytic function. Understanding the time course of neuroinflammatory changes, post-ICH may reveal novel targets for therapy and brain restoration.