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Prediction of pregnancy survival in lactating dairy cows can be determined by the conceptus attachment timeframe via daily pregnancy-specific protein B (PSPB) monitoring. All factors contributing to reduced fertility in dairy cows receiving AI following estrus detection remain unclear. This study aimed to determine differences in time to conceptus attachment in lactating cows treated with the fertility program Double-Ovsynch compared to cows that were detected in estrus. Additionally, we investigated various pre- and post-conception factors potentially influencing fertility outcomes. We hypothesized that AI following a natural estrus detected with automated activity monitors would lead to an extended time to conceptus attachment and lower PSPB concentrations post-attachment compared to Double-Ovsynch. There were no differences in the average time to conceptus attachments between treatments. However, cows inseminated post-estrus that experienced pregnancy loss between conceptus attachment and 60-66 days post-AI exhibited diminished PSPB concentrations on days 2 and 3 following conceptus attachment. Steroid hormone interactions were assessed with radioimmunoassay to determine the ratios of estrogen to progesterone concentrations on the day of the luteinizing hormone (LH) surge. Notably, estrogen to progesterone ratio proved to predict conceptus attachment in cows subjected to Double-Ovsynch but not in those inseminated post-estrus detection surge. In conclusion, the estrogen to progesterone ratio measured around the time of the pre-ovulatory LH surge emerges as a potentially effective tool for estimating the fertility potential of lactating dairy cows undergoing timed AI, particularly in the context of the Double-Ovsynch program.
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The global decline of freshwater mussels and their crucial ecological services highlight the need to understand their phylogeny, phylogeography and patterns of genetic diversity to guide conservation efforts. Such knowledge is urgently needed for Unio crassus, a highly imperilled species originally widespread throughout Europe and southwest Asia. Recent studies have resurrected several species from synonymy based on mitochondrial data, revealing U. crassus to be a complex of cryptic species. To address long-standing taxonomic uncertainties hindering effective conservation, we integrate morphometric, phylogenetic, and phylogeographic analyses to examine species diversity within the U. crassus complex across its entire range. Phylogenetic analyses were performed using cytochrome c oxidase subunit I (815 specimens from 182 populations) and, for selected specimens, whole mitogenome sequences and Anchored Hybrid Enrichment (AHE) data on â¼ 600 nuclear loci. Mito-nuclear discordance was detected, consistent with mitochondrial DNA gene flow between some species during the Pliocene and Pleistocene. Fossil-calibrated phylogenies based on AHE data support a Mediterranean origin for the U. crassus complex in the Early Miocene. The results of our integrative approach support 12 species in the group: the previously recognised Unio bruguierianus, Unio carneus, Unio crassus, Unio damascensis, Unio ionicus, Unio sesirmensis, and Unio tumidiformis, and the reinstatement of five nominal taxa: Unio desectusstat. rev., Unio gontieriistat. rev., Unio mardinensisstat. rev., Unio nanusstat. rev., and Unio vicariusstat. rev. Morphometric analyses of shell contours reveal important morphospace overlaps among these species, highlighting cryptic, but geographically structured, diversity. The distribution, taxonomy, phylogeography, and conservation of each species are succinctly described.
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Unio , Animais , Filogenia , Filogeografia , Unio/genética , Europa (Continente) , DNA Mitocondrial/genética , Variação GenéticaRESUMO
Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a "middle of the road" scenario (SSP2-4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26-43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present-day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from -20 to -191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming.
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Tartarugas , Animais , Tartarugas/fisiologia , Temperatura , Mudança Climática , Reprodução , Razão de MasculinidadeRESUMO
BACKGROUND: Food allergy (FA) is associated with poor health-related quality of life and high levels of psychological distress. Psychological support is extremely important but not always available. As part of the Global Access to Psychological Services for Food Allergy (GAPS) study, we aimed to assess psychological distress and service use among adults, caregivers and children with FA in a global survey. METHODS: Participants (n = 1329 adults with FA; n = 1907 caregivers of children with FA) from >20 countries were recruited through patient organisations, social media advertisements and online survey panels to complete an online survey. Surveys were available in six languages. RESULTS: A total of 67.7% of adults and 77.2% of caregivers reported direct experience, and 51.6% of caregivers said their child had experienced FA-related psychological distress. The most commonly reported issue was anxiety about having an allergic reaction. Less than 20% had been assessed for FA-related psychological distress. There were significant differences across countries for levels of distress, screening for distress, seeing a mental health professional and being diagnosed with a FA-related mental health disorder (all p < .001). The United Kingdom, Australia and Brazil had the highest number of participants reporting distress. The most commonly reported barrier to seeing a mental health professional was cost. CONCLUSIONS: FA-related distress is common across countries, but with substantial country-to-country variability. Allergy providers are encouraged to routinely assess families for psychological distress and provide access to appropriate mental health resources. Development and implementation of evidence-based, patient-informed accessible, affordable FA interventions in multiple languages is urgently needed.
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EUV and soft X-ray-induced photofragmentation of the halothane (CF3CHBrCl) molecule has been investigated using time-of-flight mass spectrometry in the coincidence mode (PEPICO) covering the valence region and vicinity of the bromine 3d, chlorine 2p, and carbon 1s edges. Total and partial ion yields have been recorded as a function of photon energy. At lower photon energies, the heavier singly charged molecular fragments predominate in the mass spectra. On the other hand, there is a strong tendency to the atomization of the molecule at higher photon energies. Despite the different chemical environments experienced by the two carbon atoms, weak site-specific fragmentation is observed. In addition, ab initio quantum mechanical calculations at the MP2 level and a series of computations with multiconfigurational self-consistent field have been performed to describe the inner-shell states.
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AIM: Cardiac magnetic resonance is currently an indispensable tool in the diagnosis of cardiac pathologies, with mapping techniques being one of the most recent advances in this area. T1 mapping is a robust tool that uses the T1 magnetic relaxation time as a quantitative marker of myocardial tissue composition. However, multiple T1 mapping sequences are used, and data comparing them, especially on different vendors, is limited. This study aims to determine the T1 relaxation values in the cardiac muscle of healthy individuals using GE's Discovery 3T scanner, allowing the use of the T1 mapping technique in patients on a sustained basis. MATERIAL AND METHODS: Thirty-one healthy volunteers were submitted to T1 mapping at 3T magnetic resonance imaging (MRI) equipment, with 3 being excluded from the analysis (54% women; mean age: 39.2 ± 13.9 years). The MOLLI 5(3)3 sequence was used, acquiring one short axis slice at midventricular level. Native T1 values were presented as means (± standard deviation), and t-student independent samples tests evaluated gender differences in T1 values. RESULTS: The results show an average global native T1 value of 1193 ± 39 ms, with women's values being statistically higher than men (1211 ± 40 vs 1173 ± 27 ms, respectively, p<0.006). Gender remained the only determinant of native T1 times on a multiple linear regression model that included age, ejection fraction, and T2 status. CONCLUSION: This study has established one of the few native T1 values for a 3T GE Discovery scanner that are on par with those already reported by other vendors for a similar sequence, closing the circle in full-vendor reporting.
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Imageamento por Ressonância Magnética , Humanos , Masculino , Feminino , Adulto , Valores de Referência , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Coração/diagnóstico por imagem , Voluntários SaudáveisRESUMO
OBJECTIVE: Idiopathic Parkinson's disease (PD) is characterised by alpha-synuclein (aSyn) aggregation and death of dopaminergic neurons in the midbrain. Recent evidence posits that PD may initiate in the gut by microbes or their toxins that promote chronic gut inflammation that will ultimately impact the brain. In this work, we sought to demonstrate that the effects of the microbial toxin ß-N-methylamino-L-alanine (BMAA) in the gut may trigger some PD cases, which is especially worrying as this toxin is present in certain foods but not routinely monitored by public health authorities. DESIGN: To test the hypothesis, we treated wild-type mice, primary neuronal cultures, cell lines and isolated mitochondria with BMAA, and analysed its impact on gut microbiota composition, barrier permeability, inflammation and aSyn aggregation as well as in brain inflammation, dopaminergic neuronal loss and motor behaviour. To further examine the key role of mitochondria, we also determined the specific effects of BMAA on mitochondrial function and on inflammasome activation. RESULTS: BMAA induced extensive depletion of segmented filamentous bacteria (SFB) that regulate gut immunity, thus triggering gut dysbiosis, immune cell migration, increased intestinal inflammation, loss of barrier integrity and caudo-rostral progression of aSyn. Additionally, BMAA induced in vitro and in vivo mitochondrial dysfunction with cardiolipin exposure and consequent activation of neuronal innate immunity. These events primed neuroinflammation, dopaminergic neuronal loss and motor deficits. CONCLUSION: Taken together, our results demonstrate that chronic exposure to dietary BMAA can trigger a chain of events that recapitulate the evolution of the PD pathology from the gut to the brain, which is consistent with 'gut-first' PD.
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Microbioma Gastrointestinal , Doença de Parkinson , Camundongos , Animais , Microbioma Gastrointestinal/fisiologia , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Doença de Parkinson/metabolismo , Inflamação/metabolismo , Mitocôndrias/metabolismoRESUMO
For more than three decades, major efforts in sampling and analyzing tree diversity in South America have focused almost exclusively on trees with stems of at least 10 and 2.5 cm diameter, showing highest species diversity in the wetter western and northern Amazon forests. By contrast, little attention has been paid to patterns and drivers of diversity in the largest canopy and emergent trees, which is surprising given these have dominant ecological functions. Here, we use a machine learning approach to quantify the importance of environmental factors and apply it to generate spatial predictions of the species diversity of all trees (dbh ≥ 10 cm) and for very large trees (dbh ≥ 70 cm) using data from 243 forest plots (108,450 trees and 2832 species) distributed across different forest types and biogeographic regions of the Brazilian Amazon. The diversity of large trees and of all trees was significantly associated with three environmental factors, but in contrasting ways across regions and forest types. Environmental variables associated with disturbances, for example, the lightning flash rate and wind speed, as well as the fraction of photosynthetically active radiation, tend to govern the diversity of large trees. Upland rainforests in the Guiana Shield and Roraima regions had a high diversity of large trees. By contrast, variables associated with resources tend to govern tree diversity in general. Places such as the province of Imeri and the northern portion of the province of Madeira stand out for their high diversity of species in general. Climatic and topographic stability and functional adaptation mechanisms promote ideal conditions for species diversity. Finally, we mapped general patterns of tree species diversity in the Brazilian Amazon, which differ substantially depending on size class.
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Aclimatação , Vento , Brasil , Floresta Úmida , BiodiversidadeRESUMO
Hereditary angioedema (HAE) is a severe and disabling condition characterized by recurrent episodes of subcutaneous or mucosal swelling in the skin and respiratory and gastrointestinal tracts. HAE due to C1-esterase inhibitor deficiency (C1-INH-HAE) is the most prevalent subtype. The present Iberian study compared C1-INH-HAE treatment guidelines published between 2010 and 2022 to identify the main differences in therapeutic approaches for on-demand treatment and short- and long-term prophylaxis (LTP). HAE guidelines evolved with the availability of new treatments and with a change in the management paradigm towards an individualized, patient-centered approach, where quality of life (QOL) is central. A parallel trend was observed towards increasingly frequent home-based treatment, which potentially facilitates timely interventions, provides greater flexibility and convenience, and is associated with increased QOL, enabling patients to lead more normal lives. Most innovations over the years were made for LTP, together with the advent of new therapies and awareness of patients' needs. Several prophylactic therapies with a high level of evidence became available, although formal head-to-head comparisons are lacking. The treatment goals became more ambitious, ranging from a reduction in the frequency, severity, and duration of attacks to achieving total disease control and normalization of patients' lives. The document also addresses relevant items such as changes in terminology (eg, the introduction of designations as "first-line") and the introduction of patient-reported outcome measures to assess patients' perceptions of their self-experienced QOL and well-being. Unmet needs in the management of C1-INH-HAE are identified.
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Increasing progesterone (P4) during early conceptus development may be crucial for establishment of pregnancy in dairy cattle. The objective of this study was to determine if human chorionic gonadotropin (hCG) at various times after ovulation will increase serum P4 during elongation and increase the chances for, and reduce variability to, initial increase in pregnancy-specific protein B (PSPB) following artificial insemination (AI). Time to PSPB increase was defined as the first day of increase in concentrations of PSPB between d 18 and 28 after ovulation in cows with ≥12.5% increases for 3 consecutive days compared with baseline. Lactating cows (n = 368) synchronized to Double-Ovsynch (first service) or Ovsynch (second or greater service) received one of 4 treatments: no hCG (control), or 3,000 IU of hCG on d 2 (D2), 2 and 5 (D2+5), or 5 (D5) after ovulation. All cows were examined via ultrasound on d 5 and 10 postovulation to determine percentage of cows with hCG-induced accessory CL (aCL) and to quantify and measure all luteal structures. Samples for serum P4 were collected on d 0, 5, 19, and 20 postovulation. The P4 was increased in D2, D2+5, and D5 groups compared with control. The D2+5 and D5 treatments increased aCL and P4 compared with D2 and control. The D2 treatment increased P4 on d 5 after ovulation compared with control. Serum PSPB samples were collected daily from all cows on d 18 through 28 after ovulation for determination of d of PSPB increase. Pregnancy diagnoses were performed via ultrasound examination on d 35, 63, and 100 after ovulation and AI. The D5 treatment reduced percentage of cows with, and increased the time to, PSPB increase. Primiparous cows with ipsilateral aCL had reduced pregnancy loss before d 100 postovulation compared with cows with contralateral aCL. Cows that had PSPB increase >21 d postovulation had 4× greater chances of pregnancy loss compared with cows that had PSPB increase on d 20 or 21. The highest quartile of P4 on d 5, but not on d 19 and 20, was associated with reduced time to PSPB increase. Time to PSPB increase appears to be an important measurement to understand reasons for pregnancy loss in lactating dairy cows. Increasing P4 utilizing hCG after ovulation did not enhance early pregnancy or reduce pregnancy losses in lactating dairy cows.
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Lactação , Progesterona , Gravidez , Feminino , Humanos , Bovinos , Animais , Sincronização do Estro , Gonadotropina Coriônica , Inseminação Artificial/veterinária , Hormônio Liberador de Gonadotropina , DinoprostaRESUMO
Wagyu bulls are known to have a highly exacerbated libido, as shown by the intense sexual interest of young calves. Therefore we believe that Wagyu male animals have specialized Sertoli and Leydig cells that are directly involved with the sexual precocity in this breed as mature bulls have a small scrotal circumference. This study aimed to evaluate whether there were differences in the hormone and sperm characteristics of Wagyu bulls compared with the same characteristics of subspecies Bos indicus and Bos taurus sires. Frozen-thawed semen from Wagyu, Nellore, and Angus sires were analyzed for sperm kinetics (computer-assisted sperm analysis), plasma membrane integrity, chromatin integrity, acrosome status, mitochondrial activity, lipid peroxidation and hormone [luteinizing hormone (LH) and testosterone] serum concentration. The results showed that Wagyu had lower total motility and an increased number of sperm with no motility when compared with Nellore and Angus bulls. Wagyu breed did not differ from those breeds when considering plasma and acrosome membranes integrity, mitochondrial potential, chromatin resistance, sperm lipid peroxidation or hormone (LH and testosterone) concentrations. We concluded that Wagyu sires had lower total motility when compared with Nellore and Angus bulls. Wagyu breed did not differ from these breeds when considering plasma and acrosome membranes integrity, mitochondrial potential, chromatin resistance, sperm lipid peroxidation, or hormone (LH and testosterone) concentrations.
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Sêmen , Motilidade dos Espermatozoides , Masculino , Bovinos , Animais , Contagem de Espermatozoides/veterinária , Espermatozoides , Testosterona , CromatinaRESUMO
Aiming of self-sustainable production, the search for biodegradable and biocompatible materials has brought with it the need to know the physicochemical and dielectric characteristics of polysaccharide-based composite structures, which can be used as important and promising raw materials for biotechnology and electronic industries. Galactomannans are polysaccharides, extracted from seeds and microbiological sources, consisting of mannose and galactose. In this context, this work aimed to extract, purify and characterize by XRD, FTIR and impedance spectroscopy galactomannan obtained from seeds of Adenanthera pavonina L. The purification process was made with ethyl alcohol at concentrations of 70, 80 and 90 %. Polymeric films were prepared by solvent slow evaporation at low temperatures. XRD measurements revealed that Galactomannan from Adenanthera pavonina L., after purification, has a semi-crystalline structure due to the identification of two peaks the first between 5.849° and 6.118° and the second between 20.011° and 20.247°. FTIR spectra showed the functional groups associated with monosaccharides of the galactomannan from Adenanthera pavonina L. seeds, as well as the typical polysaccharide bands and peaks, confirmed by literature data. The impedance results give an increment on the state-of-the-art of this biomaterial by showing the existence of dielectric relaxations, independent of the degree of purification, using the dielectric modulus formalism. The permittivity analysis reveals the presence of water in the structure of the film, whose dipoles contribute to the relatively high value of the dielectric constant. From the results obtained, it can be concluded that purified galactomannan has the potential for possible applications in the electronics industry as a green and eco-friendly dielectric material.
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Fabaceae , Mananas , Mananas/análise , Mananas/química , Fabaceae/química , Polissacarídeos/química , Galactose , Sementes/química , Materiais BiocompatíveisRESUMO
Summary: Background. The adrenaline autoinjector (AAi) is universally recommended as the first-line treatment for anaphylactic reactions occurring outside the medical setting. The quantification of its acquisition may help estimate the prevalence of patients at risk of anaphylaxis with an indication for AAi. Objective. Evaluation of the global and regional frequency of AAi purchases in Mainland Portugal between 2003-2017 and calculate the inherent costs in 2017. Methods. AAi acquisition distribution analysis along this period. The population was divided in two age groups according to the adrenaline dosage. Results. A total of 10,993 AAi units of 0.15mg/0.3mL and 28,619 of 0.3mg/0.3mL were acquired in these 15 years, with an annual average of 733 and 1908 units, respectively. In cumulative values terms, Lisbon showed the highest number of AAI acquired and higher prevalence per region/100,000 inhabitants in both groups. In 2017, the annual cost for each age group was 64,202.71 187,447.70 for patients and 37,706.35 / 110,113.30 for the National Health System. Conclusions. In the last 15 years, there was a progressive increase in AAi acquisition. We estimate a rate of anaphylaxis occurrence in Portugal according to AAi aquisition of 0.165%.
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Anafilaxia , Epinefrina , Humanos , Epinefrina/uso terapêutico , Anafilaxia/tratamento farmacológico , Anafilaxia/epidemiologia , Portugal/epidemiologia , Autoadministração , PrevalênciaRESUMO
Summary: Background. Metamizole, a non-steroidal anti-inflammatory drug from the pyrazolone group, is a frequent cause of immediate hypersensitivity reactions and, more rarely, of delayed drug hypersensitivity reactions. Due to its favorable pharmacokinetic characteristics, metamizole is widely used in the postoperative period for pain control. Methods. Retrospective study of patients referred for allergological study between January 2012 and June2022 for postoperative hypersensitivity reactions. Clinical and diagnostic data were collected through review of patients' medical records. Twenty patients with postoperative hypersensitivity reactions were referred, of which 10 presented delayed reactions. We analyzed the results of skin prick, intradermal and patch tests performed with an intravenous metamizole solution as well as provocation tests performed with metamizole and acetylsalicylic acid. Cross-reactivity to non-steroidal anti-inflammatory drugs was excluded by confirmation of clinical tolerance to non-steroidal anti-inflammatory drugs or by acetylsalicylic acid provocation test. Results. In 7 of the 10 patients a delayed reaction to metamizole was diagnosed. These reactions were characterized as maculopapular exanthema, occurring in multiple postoperative settings. Skin tests were negative, except in one patient with late mild erythema in the ipsilateral upper limb and no reaction at the site of intradermal injection. Delayed hypersensitivity was demonstrated by late positive metamizole provocation tests. Conclusions. This study demonstrated that for a correct diagnosis a high degree of suspicion about possible delayed hypersensitivity drug reactions to metamizole in the postoperative setting is needed. In the investigation, provocation test with metamizole was decisive for diagnostic confirmation.
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Summary: Background. Patients and Public Involvement in every stage of the patient-centered health research cycle is the key to the development of innovative solutions with an impact on patients' care. Methods. This protocol describes the development of ConectAR, a network to promote the involvement of patients with asthma and their carers in the health research cycle. Results. This protocol comprehends 4 tasks: 1) define the mission, vision, governance and activities of the network through focus groups; 2) establish the communication strategy and tools; 3) test the feasibility of the network in a Delphi study on the research priorities for asthma in Portugal; 4) coordination and dissemination activities. Conclusions. This network will improve research by ensuring that patients and carers have an active role in the co-creation of impactful solutions for asthma.
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Asma , Cuidadores , Humanos , Grupos Focais , PortugalRESUMO
Infrared thermography is suggested as a method of medical assistance for evaluating anatomical regions where there may be some inflammatory or painful condition that requires immediate medical attention. For this reason, this study aimed to characterize digital thermography of the lumbar region in police working dogs with hip osteoarthritis, 47 dogs with bilateral hip osteoarthritis were evaluated. A thermographic dorsoventral view of the dogs' backs were obtained, and mean and maximum temperatures were determined. In addition, results from the Canine Brief Pain Inventory, Liverpool Osteoarthritis in Dogs (LOAD), the Canine Orthopedic Index, and weight-bearing distribution evaluation were collected. Results were compared with an Independent Samples T-Test or ANOVA, followed by an LSD post hoc. Multiple regression was run to predict temperatures from age, sex, breed, body weight, and Orthopedic Foundation for Animals hip score and to predict clinical metrology scores and weight-bearing distribution results from temperature results. The sample included 28 males and 19 females, with a mean age of 6.3 ± 2.5 years and bodyweight of 26.9 ± 5.1 kg, with osteoarthritis hip scores of mild (70.2%), moderate (21.3%), and severe (8.5%). Significant differences were observed in mean temperatures between German Shepherd Dogs (GSD) and Labrador Retrievers (LR) (p < 0.01), and LR and Belgian Malinois (BM) (p=0.02). Mean temperature contributed to the prediction of LOAD and stiffness. LR showed significantly higher temperature values than GSD and BM. No differences were observed between osteoarthritis hip scores and mean temperature values contributed to LOAD scores' prediction. This relation needs to be addressed in further studies, involving a larger number of animals, and to determine changes in response to treatment.
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Displasia Pélvica Canina , Osteoartrite do Quadril , Feminino , Masculino , Cães , Animais , Osteoartrite do Quadril/veterinária , Termografia , Região Lombossacral , Peso CorporalRESUMO
Invited for the cover of this issue is the group of Abraham Mendoza at Stockholm University. The image depicts a Grignard reagent "turbo-charged" with a magnesium anilide additive. Read the full text of the article at 10.1002/chem.202104053.
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The synthesis of ketones through addition of organometallic reagents to aliphatic carboxylic acids is a straightforward strategy that is limited to organolithium reagents. More desirable Grignard reagents can be activated and controlled with a bulky aniline-derived turbo-Hauser base. This operationally simple procedure allows the straightforward preparation of a variety of aliphatic and perfluoroalkyl ketones alike from functionalized alkyl, aryl and heteroaryl Grignard reagents.
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Ácidos Carboxílicos , Compostos Organometálicos , Anilidas , Indicadores e Reagentes , Estrutura MolecularRESUMO
The routine analysis of polymer blends at the nanoscale is usually carried out using electron microscopy techniques such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which often require several sample preparation steps including staining with heavy metals and/or etching. Atomic force microscopy (AFM) is also commonly used, but provides no direct chemical information about the samples analyzed. AFM-IR, a recent technique which combines the AFM's nanoscale resolution with the chemical information provided by IR spectroscopy, is a valuable complement to the already established techniques. Resonance enhanced AFM-IR (contact mode) is the most commonly used measurement mode, due to its signal enhancement and relative ease of use. However, it has severe drawbacks when used in highly heterogenous samples with changing mechanical properties, such as polymer recyclates. In this work, we use the recently developed tapping mode AFM-IR to chemically image the distribution of rubber in a real-world commercially available polyethylene/polypropylene (PE/PP) recycled blend derived from municipal and household waste. Furthermore, the outstanding IR resolution of AFM-IR allowed for the detection of small PP droplets inside the PE phase. The presence of micro and nanoscale particles of other polymers in the blend was also established, and the polymers identified.
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Objectives: The mechanism behind the progression of Mild Cognitive Impairment (MCI) to Alzheimer's disease (AD) remains poorly understood. However some evidence pointed out that the co-occurrence of metabolic conditions affecting glucose homeostasis, as type 2 diabetes mellitus (T2DM), may be an important catalyst in this context. Notably, candidate drugs which modulate common pathways in the development of MCI-to-AD mediated by T2DM may offer likely therapy for AD. Nonetheless, limited pharmacological alternatives that modulate common pathways in T2DM, MCI, and AD are available. In the recent decades, studies have shown that resveratrol may act as a neuroprotective compound, but little is known about its potential in improving cognitive and metabolic aspects associated with AD progression mediated by the co-association between TDM2-MCI.Methods: In this review, we discuss possible protective mechanisms of resveratrol on shared pathways associated with AD progression mediated by T2DM-MCI co-occurrence.Results: Some studies indicated that insulin resistance and hyperglycemia may be also a T2DM risk factor for the progression of MCI-to-AD, promoting alterations in metabolic pathways associated with neuronal plasticity, and increasing pro-inflammatory environment. Interestingly, basic research and clinical trials indicate that resveratrol may modulate those pathways, showing a potential neuroprotective effect of this polyphenol.Conclusion: Therefore, there is not enough clinical data supporting the translational therapeutic use of resveratrol in this scenario.