RESUMEN

The anhydrous alkaline earth metal carbonate Be(CO3) was synthesized in a laser-heated diamond anvil cell at moderate pressures and temperatures (20(2) GPa and 1500(200) K) by a reaction of BeO with CO2. It crystallizes in the acentric, trigonal space group P3121 with Z = 3. The crystal structure was obtained from synchrotron single crystal X-ray diffraction data and confirmed by density functional theory-based calculations in combination with Raman spectroscopy. Second harmonic generation measurements were employed to verify the acentric space group symmetry. The crystal structure of Be(CO3) is characterized by the presence of isolated [CO3]2--groups and BeO4-tetrahedra. This is a new structure type and such a topology has not been observed in carbonates before. Be(CO3) can be recovered to ambient conditions and is not undergoing a phase transition during decompression.

RESUMEN

Ensuring precise drug release at target sites is crucial for effective treatment. Here, pH-responsive nanoparticles for oral administration of mycophenolate mofetil, an alternative therapy for patients with inflammatory bowel disease unresponsive to conventional treatments is developed. However, its oral administration presents challenges due to its low solubility in the small intestine and high solubility and absorption in the stomach. Therefore, this aim is to design a drug delivery system capable of maintaining drug solubility compared to the free drug while delaying absorption from the stomach to the intestine. Successful synthesis and assembly of a block copolymer incorporating a pH-responsive functional group is achieved. Dynamic light scattering indicated a significant change in hydrodynamic size when the pH exceeded 6.5, confirming successful incorporation of the pH-responsive group. Encapsulation and controlled release of mycophenolate mofetil are efficiently demonstrated, with 90% release observed at intestinal pH. In vitro cell culture studies confirmed biocompatibility, showing no toxicity or adverse effects on Caco-2 cells. In vivo oral rat studies indicated reduced drug absorption in the stomach and enhanced absorption in the small intestine with the developed formulation. This research presents a promising drug delivery system with potential applications in the treatment of inflammatory bowel disease.

RESUMEN

Background and Aims: Improving the sexual and reproductive health of adolescents remains a public health priority. Effective communication between parents and adolescents regarding sexual health and relationships is important and could influence adolescents to adopt safer sexual behaviors. However, several barriers can impede this communication in the UK population. The aim of the review is to explore barriers and facilitators, as well as wider determinants of parent-adolescent communication (PAC) on sexual health and relationships. The review will explore possible interventions aimed at promoting PAC on sexual health and relationships. Methods: The review will focus on exploring barriers and facilitators of PAC on sexual health and relationships in the United Kingdom. This study will synthesize qualitative literature to understand the significance of parent-adolescent sexual and reproductive health communication, the challenges and facilitators to effective communication in the United Kingdom. Using a detailed predetermined search strategy, the study will search for relevant studies from CINAHL, MEDLINE, PsycINFO, EMBASE, SCOPUS, Web of Science, and gray literature on Google Scholar. The Critical Appraisal Skills Program checklist will appraise the included studies' methodological quality. A thematic synthesis approach will be used to synthesize data from included studies. Conclusion: Findings from the systematic review are expected to give information on the barriers and facilitators of PAC on sexual health and relationships which will further optimize interventions to improve this type of communication and guide future research in understanding this area. Systematic review registration: The review has been registered with the International Prospective Register of Systematic Reviews CRD (PROSPERO) (CRD42022351697).

RESUMEN

Silicon pernitride, SiN2, was synthesized from the elements at 140 GPa in a laser-heated diamond anvil cell. Its crystal structure was solved and refined by means of synchrotron-based single-crystal X-ray diffraction data. The title compound crystallizes in the pyrite structure type (space group Pa , No. 205). The Si atom occupies a site with multiplicity 4 (Wyckoff letter b, site symmetry ..), while the N atom is located on a site with multiplicity 8 (Wyckoff letter c, site symmetry .3.). The crystal structure of SiN2 is comprised of slightly distorted [SiN6] octa-hedra inter-connected with each other by sharing vertices. Crystal chemical analysis of bond lengths suggests that Si has a formal oxidation state of +IV, while nitro-gen forms pernitride anions (N-N)4-.

RESUMEN

Functionalized polymer vesicles have been proven to be highly promising in biomedical applications due to their good biocompatibility, easy processability, and multifunctional responsive capacities. However, photothermal-responsive polymer vesicles triggered by near-infrared (NIR) light have not been widely reported until now. Herein, we propose a new strategy for designing NIR light-mediated photothermal polymer vesicles. A small molecule (PTA) with NIR-triggered photothermal features was synthesized by combining a D-D'-A-D'-D configuration framework with a molecular rotor function (TPE). The feasibility of the design strategy was demonstrated through density functional theory calculations. PTA moieties were introduced in the hydrophobic segment of a poly(ethylene glycol)-poly(trimethylene carbonate) block copolymer, of which the carbonate monomers were modified in the side chain with an active ester group. The amphiphilic block copolymers (PEG44-PTA2) were then used as building blocks for the self-assembly of photothermal-responsive polymer vesicles. The new class of functionalized polymer vesicles inherited the NIR-mediated high photothermal performance of the photothermal agent (PTA). After NIR laser irradiation for 10 min, the temperature of the PTA-Ps aqueous solution was raised to 56 °C. The photothermal properties and bilayer structure of PTA-Ps after laser irradiation were still intact, which demonstrated that they could be applied as a robust platform in photothermal therapy. Besides their photothermal performance, the loading capacity of PTA-Ps was investigated as well. Hydrophobic cargo (Cy7) and hydrophilic cargo (Sulfo-Cy5) were successfully encapsulated in the PTA-Ps. These properties make this new class of functionalized polymer vesicles an interesting platform for synergistic therapy in anticancer treatment.

RESUMEN

A series of isostructural Ln3 O2 (CN3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) oxoguanidinates was synthesized under high-pressure (25-54 GPa) high-temperature (2000-3000 K) conditions in laser-heated diamond anvil cells. The crystal structure of this novel class of compounds was determined via synchrotron single-crystal X-ray diffraction (SCXRD) as well as corroborated by X-ray absorption near edge structure (XANES) measurements and density functional theory (DFT) calculations. The Ln3 O2 (CN3 ) solids are composed of the hitherto unknown CN3 5- guanidinate anion-deprotonated guanidine. Changes in unit cell volumes and compressibility of Ln3 O2 (CN3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) compounds are found to be dictated by the lanthanide contraction phenomenon. Decompression experiments show that Ln3 O2 (CN3 ) compounds are recoverable to ambient conditions. The stabilization of the CN3 5- guanidinate anion at ambient conditions provides new opportunities in inorganic and organic synthetic chemistry.

RESUMEN

The stabilization of nitrogen-rich phases presents a significant chemical challenge due to the inherent stability of the dinitrogen molecule. This stabilization can be achieved by utilizing strong covalent bonds in complex anions with carbon, such as cyanide CN- and NCN2- carbodiimide, while more nitrogen-rich carbonitrides are hitherto unknown. Following a rational chemical design approach, we synthesized antimony guanidinate SbCN3 at pressures of 32-38 GPa using various synthetic routes in laser-heated diamond anvil cells. SbCN3 , which is isostructural to calcite CaCO3 , can be recovered under ambient conditions. Its structure contains the previously elusive guanidinate anion [CN3 ]5- , marking a fundamental milestone in carbonitride chemistry. The crystal structure of SbCN3 was solved and refined from synchrotron single-crystal X-ray diffraction data and was fully corroborated by theoretical calculations, which also predict that SbCN3 has a direct band gap with the value of 2.20 eV. This study opens a straightforward route to the entire new family of inorganic nitridocarbonates.

RESUMEN

We demonstrate the construction of pH-responsive bicontinuous nanospheres (BCNs) with nonlinear transient permeability and catalytic activity. The BCNs were assembled from amphiphilic block copolymers comprising pH-responsive groups and were loaded with the enzymes urease and horseradish peroxidase (HRP). A transient membrane permeability switch was introduced by employing the well-known pH-increasing effect of urease upon conversion of urea to ammonia. As expected, the coencapsulated HRP displayed a transiently regulated catalytic output profile upon addition of urea, with no significant product formation after the pH increase. This transient process displayed a nonlinear "dampening" behavior, induced by a decrease in membrane permeability as a result of significant local ammonia production. Furthermore, the catalytic output of HRP could be modulated by addition of different amounts of urea or by altering the buffer capacity of the system. Finally, this nonlinear dampening effect was not observed in spherical polymersomes, even though the membrane permeability could also be inhibited by addition of urea. The specific BCN morphology therefore allows to optimally control catalytic processes by pH changes in the nanoreactor microenvironment compared to bulk conditions due to its unique permeability profile.

RESUMEN

The annual Namaqualand daisy flowering spectacle is a world-renowned environmental event. Using documentary sources, including newspaper archives from The Rand Daily Mail, Volksblad and Die Burger and social media records from Flickr and iNaturalist, the first long-term phenological dataset spanning 1935-2018 was compiled for the Namaqualand region. The dataset contains first flowering, full bloom and end of bloom dates for the Namaqualand daisies. This study explores shifts in the timing of Namaqualand daisy bloom, and the role of climate in driving these phenological shifts. First flowering and full bloom phenology of the Namaqualand daisies are advancing at statistically significant rates of 2.6 days decade-1 and 2.1 days decade-1 respectively. Climatic data from seven Namaqualand weather stations, collectively spanning 1959-2018, were interrogated. For the periods spanned by both climate and phenology data, the relationships between the two were explored. Increasing temperatures are driving the calculated advances of the daisy flowering dates at statistically significant rates of change ranging from 0.01 to 0.11 days °C-1. The main climate drivers of Namaqualand daisy flowering phenology are winter and spring temperatures, the onset of the winter rainy season during April and May, and total winter precipitation. The rates of advance and climate drivers are broadly consistent with global phenological meta-analyses and records for the Southern Hemisphere. The advances in the timing of Namaqualand daisy flowering will have a significant impact on the tourism sector in the region, as flower viewing tours need to be prearranged months in advance.

Asunto(s)

Cambio Climático , Flores , Humanos , Estaciones del Año , Sudáfrica , Temperatura

RESUMEN

Motoric disturbances in Parkinson's disease (PD) derive from the loss of dopaminergic neurons in the substantia nigra. Intestinal dysfunctions often appear long before manifestation of neuronal symptoms, suggesting a strong correlation between gut and brain in PD. Oxidative stress is a key player in neurodegeneration causing neuronal cell death. Using natural antioxidative flavonoids like Rutin, might provide intervening strategies to improve PD pathogenesis. To explore the potential effects of micro (mRutin) compared to nano Rutin (nRutin) upon the brain and the gut during PD, its neuroprotective effects were assessed using an in vitro PD model. Our results demonstrated that Rutin inhibited the neurotoxicity induced by A53T α-synuclein (Syn) administration by decreasing oxidized lipids and increasing cell viability in both, mesencephalic and enteric cells. For enteric cells, neurite outgrowth, number of synaptic vesicles, and tyrosine hydroxylase positive cells were significantly reduced when treated with Syn. This could be reversed by the addition of Rutin. nRutin revealed a more pronounced result in all experiments. In conclusion, our study shows that Rutin, especially the nanocrystals, are promising natural compounds to protect neurons from cell death and oxidative stress during PD. Early intake of Rutin may provide a realizable option to prevent or slow PD pathogenesis.

Asunto(s)

Sistema Nervioso Entérico , alfa-Sinucleína , Antioxidantes/farmacología , Neuronas Dopaminérgicas , Rutina/farmacología

RESUMEN

The use of well-defined nanovesicles composed of amphiphilic block copolymers (polymersomes) for delivery of adjuvants and antigens is a promising strategy for vaccine development. However, the potency of nanoparticle vaccines depends on efficient interaction with and activation of cells involved in antigen presentation, which can be achieved by targeting cellular receptors. Here, we showed that the Fc fragment display on the polymersome surface resulted in markedly improved interactions with granulocytes, monocytes, and NK cells, while for "naked" polymersomes, virtually no binding to leukocytes was observed. Moreover, CpG-decorated polymersomes were found to also interact with T and/or B cells. Interestingly, whole blood stimulations with Fc fragment and CpG-decorated polymersomes induced interleukin (IL)-6, IL-8, and TNF-α production, while naked polymersomes did not induce any cytokine production. In conclusion, specific immune induction by polymersomes can be controlled using bimodal targeting of different immune receptors, which is an essential feature for targeted vaccine delivery.

Asunto(s)

Nanopartículas , Polímeros , Adyuvantes Inmunológicos/farmacología , Sistemas de Liberación de Medicamentos , Humanos , Leucocitos

Asunto(s)

Ácidos Grasos Omega-3 , Síndrome de Dificultad Respiratoria , Enfermedad Crítica , Humanos

RESUMEN

Mitochondrial dysfunction represents a hallmark of both brain aging and age-related neurodegenerative disorders including Alzheimer disease (AD). AD-related mitochondrial dysfunction is characterized by an impaired electron transport chain (ETC), subsequent decreased adenosine triphoshpate (ATP) levels, and elevated generation of reactive oxygen species (ROS). The bioactive citrus flavanone hesperetin (Hst) is known to modulate inflammatory response, to function as an antioxidant, and to provide neuroprotective properties. The efficacy in improving mitochondrial dysfunction of Hst nanocrystals (HstN) with increased bioavailability has not yet been investigated. Human SH-SY5Y cells harboring neuronal amyloid precursor protein (APP695) acted as a model for the initial phase of AD. MOCK-transfected cells served as controls. The energetic metabolite ATP was determined using a luciferase-catalyzed bioluminescence assay. The activity of mitochondrial respiration chain complexes was assessed by high-resolution respirometry using a Clarke electrode. Expression levels of mitochondrial respiratory chain complex genes were determined using quantitative real-time polymerase chain reaction (qRT-PCR). The levels of amyloid ß-protein (Aß1-40) were measured using homogeneous time-resolved fluorescence (HTRF). ROS levels, peroxidase activity, and cytochrome c activity were determined using a fluorescence assay. Compared to pure Hst dissolved in ethanol (HstP), SH-SY5Y-APP695 cells incubated with HstN resulted in significantly reduced mitochondrial dysfunction: ATP levels and respiratory chain complex activity significantly increased. Gene expression levels of RCC I, IV, and V were significantly upregulated. In comparison, the effects of HstN on SY5Y-MOCK control cells were relatively small. Pure Hst dissolved in ethanol (HstP) had almost no effect on both cell lines. Neither HstN nor HstP led to significant changes in Aß1-40 levels. HstN and HstP were both shown to lower peroxidase activity significantly. Furthermore, HstN significantly reduced cytochrome c activity, whereas HstP had a significant effect on reducing ROS in SH-SY5Y-APP695 cells. Thus, it seems that the mechanisms involved may not be linked to altered Aß production. Nanoflavonoids such as HstN have the potential to prevent mitochondria against dysfunction. Compared to its pure form, HstN showed a greater effect in combatting mitochondrial dysfunction. Further studies should evaluate whether HstN protects against age-related mitochondrial dysfunction and thus may contribute to late-onset AD.

Asunto(s)

Bacteriemia , Stenotrophomonas maltophilia , Compuestos de Azabiciclo , Aztreonam , Humanos

RESUMEN

Poor aqueous solubility of drug substances is associated with poor bioavailability and thus hampers the effective use of many potent active pharmaceutical ingredients. Various strategies to overcome poor solubility are available, whereby drug nanocrystals represent one of the most powerful formulation strategies to enhance the kinetic solubility and dissolution rate of poorly soluble drugs. Nanocrystals are simply obtained by milling large-sized drug powders to sizes < 1 µm. The so obtained nanocrystals possess an increased dissolution rate and kinetic solubility when compared with larger-sized bulk material. The aim of this study was to produce differently sized hesperetin nanocrystals and to investigate the influence of nanocrystal size on the bioefficacy of the natural antioxidant hesperetin in two cell culture models for the prevention and treatment of Alzheimer's disease. Results showed that the testing of poorly soluble compounds is challenging and requires incredibly careful characterization. Reasons for this are possible changes of the formulations in cell culture media which can occur due to various reasons. If the changes are not considered, results obtained can be misleading and even lead to a false interpretation of the results obtained. Besides, results demonstrate the increase in dissolution rate with decreasing particle size that is especially pronounced with particle sizes < 200 nm. Data also provide clear evidence that smaller nanocrystals with higher kinetic solubility possess higher antioxidant capacity. This results in lower amounts of free radicals in the cell culture models, suggesting that hesperetin nanocrystals, that improve the poor aqueous solubility of hesperetin, are promising for the prevention and treatment of Alzheimer's disease.

Asunto(s)

Enfermedad de Alzheimer , Hesperidina , Nanopartículas , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/prevención & control , Humanos , Solubilidad

RESUMEN

Isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) mutations in Myeloid Neoplams (MNs) exhibit DNA hypermethylation via 2-hydroxyglutarate (2HG) over-production. Clinical impact of azacitidine (AZA) remains inconsistent in IDH1/2-mutated MNs and the potential of serum 2HG as a suitable marker of response to AZA is unknown. To address these questions, we retrospectively analyzed 93 MNs patients (78 AML, 11 MDS, 4 CMML) with IDH1/2 mutations treated with AZA. After a median of 5 cycles of AZA, overall response rate was 28% (including 15% complete remission) and median OS was 12.3 months (significantly shorter in AML compared to MDS/CMML patients). In multivariate analysis of AML patients, DNMT3A mutation was associated with shorter OS while IDH1/2 mutation subtypes had no independent impact. No difference was observed in serum 2HG levels upon AZA treatment between responding and refractory patients suggesting that serum 2HG cannot be used as a surrogate marker of AZA response.

Asunto(s)

Leucemia Mieloide Aguda , Síndromes Mielodisplásicos , Azacitidina/uso terapéutico , Humanos , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Mutación , Estudios Retrospectivos

RESUMEN

OBJECTIVE: Huntington's disease (HD) is characterized by psychiatric, cognitive, and motor disturbances. The study aimed to determine electroencephalography (EEG) global state and microstate changes in HD and their relationship with cognitive and behavioral impairments. METHODS: EEGs from 20 unmedicated HD patients and 20 controls were compared using global state properties (connectivity and dimensionality) and microstate properties (EEG microstate analysis). For four microstate classes (A, B, C, D), three parameters were computed: duration, occurrence, coverage. Global- and microstate properties were compared between groups and correlated with cognitive test scores for patients. RESULTS: Global state analysis showed reduced connectivity in HD and an increasing dimensionality with increasing HD severity. Microstate analysis revealed parameter increases for classes A and B (coverage), decreases for C (occurrence) and D (coverage and occurrence). Disease severity and poorer test performances correlated with parameter increases for class A (coverage and occurrence), decreases for C (coverage and duration) and a dimensionality increase. CONCLUSIONS: Global state changes may reflect higher functional dissociation between brain areas and the complex microstate changes possibly the widespread neuronal death and corresponding functional deficits in brain regions associated with HD symptomatology. SIGNIFICANCE: Combining global- and microstate analyses can be useful for a better understanding of progressive brain deterioration in HD.

Asunto(s)

Mapeo Encefálico , Encéfalo/fisiopatología , Electroencefalografía , Enfermedad de Huntington/fisiopatología , Adulto , Estudios de Casos y Controles , Trastornos del Conocimiento/fisiopatología , Progresión de la Enfermedad , Femenino , Humanos , Enfermedad de Huntington/complicaciones , Masculino , Trastornos Mentales/fisiopatología , Índice de Severidad de la Enfermedad

RESUMEN

BACKGROUND: The relationship between inhaled corticosteroids and bone mineral density (BMD) remains uncertain despite extensive research. METHODS: This was an international, multicenter, randomized, double-blind, parallel-group, 3-year noninferiority study. Patients with chronic obstructive pulmonary disease (COPD) (⩾40 years of age; smoking history ⩾10 pack years) and at least one native hip evaluable for BMD were enrolled and randomized 1:1, stratified by sex, to treatment with vilanterol (VI) 25 µg or fluticasone furoate/vilanterol (FF/VI) 100 µg/25 µg. BMD measurements were taken via dual-energy X-ray absorptiometry every 6 months. The primary endpoint was assessment of the noninferiority of change from baseline in total hip BMD per year at the -1% noninferiority level. Change from baseline in BMD at the lumbar spine and BMD measurements by sex were secondary endpoints. Incidences of COPD exacerbations and bone fractures throughout the study were also recorded. RESULTS: Of 283 randomized patients, 170 (60%) completed the study. Noninferiority was demonstrated for FF/VI versus VI with regards to change from baseline in total hip BMD per year, with changes of -0.27% and 0.18%, respectively, and a treatment difference of -0.46% per year [95% confidence interval (CI) -0.97 to 0.06]. The treatment difference for FF/VI versus VI regarding lumbar spine BMD was -0.51% per year (95% CI -1.11 to 0.10). COPD exacerbations and bone fracture rates were similar between treatment groups. CONCLUSION: FF/VI showed noninferiority to VI for change from baseline in total hip BMD per year, when assessed at the -1% noninferiority margin in a combined sample of men and women with COPD.The reviews of this paper are available via the supplemental material section.

Asunto(s)

Corticoesteroides/administración & dosificación , Agonistas de Receptores Adrenérgicos beta 2/administración & dosificación , Androstadienos/administración & dosificación , Alcoholes Bencílicos/administración & dosificación , Densidad Ósea/efectos de los fármacos , Clorobencenos/administración & dosificación , Pulmón/efectos de los fármacos , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Administración por Inhalación , Corticoesteroides/efectos adversos , Agonistas de Receptores Adrenérgicos beta 2/efectos adversos , Anciano , Androstadienos/efectos adversos , Alcoholes Bencílicos/efectos adversos , Canadá , Clorobencenos/efectos adversos , Método Doble Ciego , Esquema de Medicación , Combinación de Medicamentos , Europa (Continente) , Femenino , Humanos , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos

RESUMEN

The COVID-19 pandemic is increasing the need for international food assistance, and disrupting the supply and delivery of food assistance. A series of unprecedented shocks is straining the capacity of food assistance organizations to reach vulnerable populations. We discuss how the COVID-19 pandemic is affecting the demand and the supply of international food assistance, and we propose three policy changes that can keep food flowing to those in need. First, donor countries can prioritize humanitarian spending in aid-allocation decisions. Second, governments can exempt food assistance from trade barriers that impede procurement (export restrictions) and delivery (import tariffs). Third, donor countries can allow flexibility for implementing agencies by untying food assistance from domestic procurement and shipping restrictions. All of these proposals are regulatory changes that can be made without requiring increased spending. These options are particularly relevant now because donor-country governments are entering economic recessions, and foreign aid budgets will be constrained.