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Key Clinical Message: Accurately identifying the ruptured aneurysm in patients with subarachnoid hemorrhage and multiple aneurysms is critical to prevent rebleeding and optimize outcomes. Vessel wall MRI with contrast can aid in pinpointing the culprit aneurysm, informing a tailored surgical or endovascular management strategy for these complex cases. In patients with subarachnoid hemorrhage (SAH) and multiple intracranial aneurysms, MRI with contrast and DSA are crucial for identifying the ruptured aneurysm, guiding a shift from endovascular to microsurgical clipping. Successful single-session treatment and absence of postsurgical deficits highlight the effectiveness of a multidisciplinary approach. Further research on optimal strategies is needed. Abstract: Multiple intracranial aneurysms make up approximately 20% of cases of aneurysmal SAH. In patients with aneurysmal SAH and multiple intracranial aneurysms, definite treatment of the ruptured aneurysm causing SAH is of the highest priority. However, identifying the bleeding source can be challenging, and it may not be recognizable by the hemorrhage pattern. Misdiagnosis and mistreatment of a ruptured aneurysm in a patient with multiple aneurysms can lead to bleeding recurrence and an undesirable outcome. We report a 65-year-old woman who presented with severe sudden onset headache. Neuroimaging studies revealed diffuse SAH and concurrent PICA and ACom aneurysm with triplicate A2. However, the ruptured aneurysm responsible for the patient's symptoms was not obvious based on routine neuroimaging studies. Magnetic resonance imaging with contrast was performed, revealing circumferential enhancement of the PICA aneurysm. In this report, we demonstrate the real-world effect of vessel wall MRI with contrast on decision-making regarding identifying the ruptured aneurysm and surgical planning in cases of multiple aneurysms. Furthermore, we show that MRI and aneurysm wall enhancement could be a promising option in detecting ruptured aneurysms in cases of multiple aneurysms.
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Anxiety is an adaptive condition characterized by heightened uneasiness, which in the long term can cause complications such as reducing the quality of life and problems related to the mental and physical health. Concerns have been raised regarding the potential dangers of extremely low frequency electromagnetic fields (ELF-EMF) ranging from 3 to 3000 Hz, which are omnipresent in our daily lives and there have been studies about the anxiogenic effects of these fields. Studies conducted in this specific area has revealed that ELF-EMF can have an impact on various brain regions, such as the hippocampus. In conclusion, studies have shown that ELF-EMF can interfere with hippocampus-prefrontal cortex pathway, inducing anxiety behavior. Also, ELF-EMF may initiate anxiety behavior by generating oxidative stress in hypothalamus and hippocampus. Moreover, ELF-EMF may induce anxiety behavior by reducing hippocampus neuroplasticity and increasing the NMDA2A receptor expression in the hippocampus. Furthermore, supplementation with antioxidants could serve as an effective protective measure against the adverse effects of FLF-FMF in relation to anxiety behavior.
In the modern world, the use of electric devices is inevitable and our living environment is full of these devices that create waves called electromagnetic fields. A group of these waves have extremely low frequencies, and many researches have been done on their effects on the behavior of laboratory animals such as rats and mice. Many of these studies indicate that these types of waves are anxiogenic, and a number of human studies also confirm this effect. In this study, we decided to search for the possible mechanisms behind this effect. Our review of the studies conducted in this field determined that the main effect of extremely low frequency fields which can have on different parts of the brain, causing anxiety behavior, is oxidative stress. Of course, studies show that the use of antioxidants, can prevent the oxidative effects of this type of waves.
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Key Clinical Message: Intracranial RDD is rare medical event mimicking different diagnoses. Although the surgical resection is the best treatment option, but radiation therapy can also achieves long-term suboptimal outcomes. Abstract: An 83-year-old male with a history of tension-type headaches was evaluated. He was conscious with no focal neurological deficits. His brain MRI revealed an enhancable bifrontal tumor originating from falx cerebri and superior sagittal sinus dura. Due to the patient's preference and decline for gross total resection, she underwent a stereotactic biopsy. The pathology was positive for Rosai-Dorfman diseases. He received definitive targeted radiation with a total dose of 4500 cGy administered in 200 cGy daily fractions. His 4-year follow-up showed regional tumor control with excellent neurological outcome.
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BACKGROUND: Ophthalmic artery aneurysm (OAA) can be secured in endovascular or microsurgical approaches. Still there are controversies in technique selection and their long term outcomes. METHODS: All the patients with OAA were treated microsurgically and followed. Demographic data, neurological status, physical examination findings, angiographic data, operation details, and intraoperative and postoperative events were recorded and analyzed. P < 0.05 was considered significant. RESULTS: Among 55 patients, 38 were females (69.1%). Median preoperative glasgow coma scale (GCS), Fisher Grade, and Hunt and Hess(HH) scores were 15, 1 and 1, respectively. The most common neurologic manifestation was visual problems (n = 15). The most common anatomical projection was medial (43.6%) oriented lesions. 85.5% of them only had 1 ophthalmic aneurysm while multiple aneurysms were reported in 14.6%. In 52 patients temporary clip was used. in 21 patients (38.2%) intraoperative aneurysm rupture occurred. Larger aneurysm size and preoperative hydrocephalus were associated with higher rates of aneurysm rupture (P = 0.003 and 0.031). 28.5% of the patients with visual problems had clinical improvement in the postoperative period. The mean follow-up period was 5 years. Follow-up angiography showed a 100% obliteration rate with a 0.0% recurrence rate. Median values for follow-up glasgow outcome scale and modified Rankin scale were 5 and 0, respectively. favorable neurological outcomes were associated with better primary GCS and HH scores. CONCLUSION: OAA microsurgery is an effective and safe procedure with significant improvement in both visual and neurological status. Low recurrence rate and excellent clinical recovery are the most important advantages of microsurgery in OAA treatment.
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Aneurisma Intracraniano , Microcirurgia , Artéria Oftálmica , Humanos , Feminino , Masculino , Microcirurgia/métodos , Pessoa de Meia-Idade , Artéria Oftálmica/cirurgia , Adulto , Seguimentos , Aneurisma Intracraniano/cirurgia , Aneurisma Intracraniano/complicações , Idoso , Resultado do Tratamento , Estudos Retrospectivos , Adulto Jovem , AdolescenteRESUMO
BACKGROUND: Traumatic intracranial aneurysms (TICAs) constitute a notable portion of pediatric intracranial aneurysms. Their unstable structure dictates a high incidence of rupture or mass effect from enlarging unruptured aneurysms, necessitating prompt diagnosis and treatment. TICAs often lack a true neck or are wide-necked, making them unsuitable for coil embolization and surgical clipping, and their fragile nature poses a risk of rupture during surgical and intrasaccular interventions. Endoluminal flow diverters (FD), deployed without requiring direct access to the aneurysmal sac, have emerged as an appealing sole treatment modality for TICAs. However, the clinical experience with this technique remains limited in the pediatric population. METHOD: We describe the successful treatment of a paraclinoid TICA in a 4-year-old female using an endoluminal FD alone. Additionally, we conducted a literature review to assess the safety and effectiveness of this treatment modality in pediatric TICAs. RESULTS: Endoluminal flow diversion led to complete aneurysm obliteration in our case, with no observed complication, at the 9-month follow-up. Our review of the previously reported pediatric TICAs managed by standalone flow diversion highlights this technique as safe, efficient, and promising as a sole treatment modality, particularly in the anterior circulation, with a high rate of persistent total obliteration and a low rate of complications. However, the requirement for long-term antiplatelet therapy with the possibility of frequent dose monitoring and adjustments warrants special attention when using endoluminal FDs. Until guidelines specifically addressing optimal antiplatelet therapy in children with intracranial FDs are formulated, adherence to existing protocols is imperative to avoid in-stent thrombosis. CONCLUSION: Our literature review and personal experience indicate that endoluminal flow diversion can be a viable treatment approach for pediatric TICAs. However, prospective studies with extensive follow-ups are required to assess the durability of endoluminal FDs in treating pediatric TICAs, considering the long life expectancy of this demographic.
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Embolização Terapêutica , Procedimentos Endovasculares , Aneurisma Intracraniano , Feminino , Humanos , Criança , Pré-Escolar , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Estudos Prospectivos , Inibidores da Agregação Plaquetária , Resultado do Tratamento , Procedimentos Endovasculares/métodos , Embolização Terapêutica/métodos , Stents , Estudos RetrospectivosRESUMO
Membrane-based salinity gradient energy generation from the osmotic potential at the interface of a river and seawater through reverse electrodialysis is a promising route for realizing clean, abundant, and sustainable energy. Membrane permeability and selective ion transport are crucial for efficient osmotic energy harvesting. However, balancing these two parameters in the membrane design and synthesis remains challenging. Herein, a hybridized bilayer metal-organic frameworks (MOF-on-MOF) membrane is fabricated for efficient transmembrane conductance for enhanced osmotic power generation. The heterogeneous membrane is constructed from imidazolate framework-8 (ZIF-8) deposited on a UiO-66-NH2 membrane intercalated with poly(sodium-4-styrenesulfonate) (PSS). The angstrom-scale cavities in the ZIF-8 layer promote ion selectivity by size exclusion, and the PSS-intercalated UiO-66-NH2 film ensures cation permeability. The synergistic effect is a simultaneous improvement in ion transport and selectivity from an overlapped electric double layer generating 40.01 W/m2 and 665 A/m2 permeability from a 500-fold concentration gradient interface at 3 KΩ and 9.20 W/m2 from mixing of real sea-river water. This work demonstrates a rational design strategy for hybrid membranes with improved ion selectivity and permeability for the water-energy nexus.
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Despite being a pillar of high-performance materials in industry, manufacturing carbon fiber composites with simultaneously enhanced multifunctionality and structural properties has remained elusive due to the lack of practical bottom-up approaches with control over nanoscale interactions. Guided by the droplet's internal currents and amphiphilicity of nanomaterials, herein, a programmable spray coating is introduced for the deposition of multiple nanomaterials with tailorable patterns in composite. It is shown that such patterns regulate the formation of interfaces, damage containment, and electrical-thermal conductivity of the composites, which is absent in conventional manufacturing that primarily rely on incorporating nanomaterials to achieve specific functionalities. Molecular dynamics simulations show that increasing the hydrophilicity of the hybrid nanomaterials, which is synchronous with shifting patterns from disk to ring, improves the interactions between the carbon surfaces and epoxy at the interfaces,manifested in enhanced interlaminar and flexural performance. Transitioning from ring to disk creates a larger interconnected network leading to improved thermal and electrical properties without penalty in mechanical properties. This novel approach introduces a new design , where the mechanical and multifunctional performance is controlled by the shape of the deposited patterns, thus eliminating the trade-off between properties that are considered paradoxical in today's manufacturing of hierarchical composites.
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Arteriovenous fistula and spinal aneurysms like other vascular malformations can mimic radiculopathy and low back pain. Precise imaging work combined with a hybrid endovascular-microsurgical approach is the key element for the best clinical outcome.
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OBJECTIVE: Prenatal stress (PS) is a problematic situation resulting in psychological implications such as social anxiety. Ubiquitous extremely low-frequency electromagnetic fields (ELF-EMF) have been confirmed as a potential physiological stressor; however, useful neuroregenerative effect of these types of electromagnetic fields has also frequently been reported. The aim of the present study was to survey the interaction of PS and ELF-EMF on anxiety-like behavior. METHOD: A total of 24 female rats 40 days of age were distributed into four groups of 6 rats each: control, stress (their mothers were exposed to stress), EMF (their mothers underwent to ELF-EMF), and EMF/stress (their mothers concurrently underwent to stress and ELF-EMF). The rats were assayed using elevated plus-maze and open field tests. RESULTS: Expressions of the hippocampus GAP-43, BDNF, and caspase-3 (cas-3) were detected by immunohistochemistry in Cornu Ammonis 1 (CA1) and dentate gyrus (DG) of the hippocampus and prefrontal cortex (PFC). Anxiety-like behavior increased in all treatment groups. Rats in the EMF/stress group presented more serious anxiety-like behavior. In all treatment groups, upregulated expression of cas-3 was seen in PFC, DG, and CA1 and downregulated expression of BDNF and GAP-43 was seen in PFC and DG and the CA1. Histomorphological study showed vast neurodegenerative changes in the hippocampus and PFC. CONCLUSION: The results showed ,female rats that underwent PS or/and EMF exhibited critical anxiety-like behavior and this process may be attributed to neurodegeneration in PFC and DG of the hippocampus and possibly decreased synaptic plasticity so-called areas.
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Fator Neurotrófico Derivado do Encéfalo , Campos Eletromagnéticos , Feminino , Ratos , Animais , Campos Eletromagnéticos/efeitos adversos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína GAP-43/metabolismo , Hipocampo/metabolismo , Córtex Pré-Frontal/metabolismo , Ansiedade/etiologiaRESUMO
There is a disagreement on whether extremely low frequency electromagnetic fields (ELF-EMF) have a beneficial or harmful effect on anxiety-like behavior. Prenatal stress induces frequent disturbances in offspring physiology such as anxiety-like behavior extending to adulthood. This study was designed to evaluate the effects of prenatal stress and ELF-EMF exposure before and during pregnancy on anxiety-like behavior and some anxiety-related pathways in the hippocampus of female rat offspring. A total of 24 female rats 40 days of age were distributed into four groups of 6 rats each: control, Stress (rats whose mothers underwent chronic stress), EMF (rats whose mothers were exposed to electromagnetic fields) and EMF/S (rats whose mothers were simultaneously exposed to chronic stress and ELF-EMF). The rats were given elevated plus-maze and open field tests and then their brains were dissected and their hippocampus were subjected to analysis. ELISA was used to measure 24(S)-hydroxy cholesterol, corticosterone, and serotonin levels. Cryptochrome2, steroidogenic acute regulatory protein, 3B-Hydroxy steroid dehydrogenase, N-methyl-D-aspartate receptor 2(NMDAr2) and phosphorylated N-methyl-D-aspartate receptor 2(PNMDAr2) were assayed by immunoblotting. Anxiety-like behavior increased in all treatment groups at the same time EMF increased anxiety induced by maternal stress in the EMF/S group. The stress group showed decreased serotonin and increased corticosterone levels. ELF-EMF elevated the PNMDAr2/NMDAr2 ratio and 24(S)-hydroxy cholesterol compared to the control group but did not change corticosterone. EMF did not restore changes induced by stress in behavioral and molecular tests. The results of the current study, clarified that ELF-EMF can induce anxiety-like behavior which may be attributed to an increase in the PNMDAr2/NMDAr2 ratio and 24(S)-OHC in the hippocampus, and prenatal stress may contribute to anxiety via a decrease in serotonin and an increase in corticosterone in the hippocampus. We also found that anxiety-like behavior induced by maternal stress exposure, is exacerbated by electromagnetic fields radiation.
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Corticosterona , Campos Eletromagnéticos , Animais , Ansiedade/etiologia , Campos Eletromagnéticos/efeitos adversos , Feminino , Ratos , Receptores de N-Metil-D-Aspartato , Serotonina , Estresse PsicológicoRESUMO
Dispersing carbon nanomaterials in solvents is effective in transferring their significant mechanical and functional properties to polymers and nanocomposites. However, poor dispersion of carbon nanomaterials impedes exploiting their full potential in nanocomposites. Cellulose nanocrystals (CNCs) are promising for dispersing and stabilizing pristine carbon nanotubes (pCNTs) and graphene nanoplatelets (pGnP) in protic media without functionalization. Here, the underlying mechanisms at the molecular level are investigated between CNC and pCNT/pGnP that stabilize their dispersion in polar solvents. Based on the spectroscopy and microscopy characterization of CNCpCNT/pGnP and density functional theory (DFT) calculations, an additional intermolecular mechanism is proposed between CNC and pCNT/pGnP that forms carbonoxygen covalent bonds between hydroxyl end groups of CNCs and the defected sites of pCNTs/pGnPs preventing re-agglomeration in polar solvents. This work's findings indicate that the CNC-assisted process enables new capabilities in harnessing nanostructures at the molecular level and tailoring the performance of nanocomposites at higher length scales.
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Nanocompostos , Nanopartículas , Nanotubos de Carbono , Celulose/química , Nanocompostos/química , Nanopartículas/química , Solventes , ÁguaRESUMO
AIM: To examine the screening value of the serum level of interleukin-1ß (IL-1ß) in aneurysmal subarachnoid hemorrhage (SAH), and to evaluate its association with the severity of initial bleeding. MATERIAL AND METHODS: This case-control study was performed in Namazi Hospital, affiliated to Shiraz University of Medical Sciences, Shiraz, Iran. The study population included patients referred to Namazi Hospital with a diagnosis of SAH, whose symptoms had emerged within less than 48 hours. The case group consisted of patients with cerebral aneurysms, who were divided into two groups of raptured and un-raptured brain aneurysms. This study examined the relationship between the serum IL-1ß levels and brain aneurysms. The number of samples was 43 per group and 86 in total. Forty-eight hours before the onset of symptoms and before surgery, a blood sample was collected to measure the IL-1Β antibody (anti-IL-1ß) level; in less than three hours, the serum was isolated and placed in a -80ºC freezer. RESULTS: In patients with unruptured aneurysms, the Fisher's grade was 0, while most ruptured aneurysms were grade 3. The middle cerebral artery (MCA) (n=10, 23%) was the most common site of aneurysm, followed by the anterior communicating artery (ACom) (n=9, 20%). There was a significant correlation between ruptured aneurysms and the Glasgow Comma Scale (GCS) score (p=0.01) and also Fisher's classification (p=0.04). Patients with ruptured and unruptured aneurysms showed no significant differences regarding the serum IL-1ß levels. A significant difference was found in the serum level of IL-1ß between the case and control groups (p=0.04). CONCLUSION: Generally, knowledge of the association between aneurysm development and inflammatory response can have significant clinical implications in the future. The present findings suggested a significant correlation between the IL-1ß levels and the outcomes of aneurysmal SAH, independent of initial hemorrhage.
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Aneurisma Roto , Aneurisma Intracraniano , Hemorragia Subaracnóidea , Aneurisma Roto/cirurgia , Estudos de Casos e Controles , Grupos Controle , Humanos , Interleucina-1beta , Aneurisma Intracraniano/cirurgia , Hemorragia Subaracnóidea/complicaçõesRESUMO
Biological ion channels feature angstrom-scale asymmetrical cavity structures, which are the key to achieving highly efficient separation and sensing of alkali metal ions from aqueous resources. The clean energy future and lithium-based energy storage systems heavily rely on highly efficient ionic separations. However, artificial recreation of such a sophisticated biostructure has been technically challenging. Here, a highly tunable design concept is introduced to fabricate monovalent ion-selective membranes with asymmetric sub-nanometer pores in which energy barriers are implanted. The energy barriers act against ionic movements, which hold the target ion while facilitating the transport of competing ions. The membrane consists of bilayer metal-organic frameworks (MOF-on-MOF), possessing a 6 to 3.4-angstrom passable cavity structure. The ionic current measurements exhibit an unprecedented ionic current rectification ratio of above 100 with exceptionally high selectivity ratios of 84 and 80 for K+ /Li+ and Na+ / Li+ , respectively (1.14 Li+ mol m-2 h-1 ). Furthermore, using quantum mechanics/molecular mechanics, it is shown that the combined effect of spatial hindrance and nucleophilic entrapment to induce energy surge baffles is responsible for the membrane's ultrahigh selectivity and ion rectification. This work demonstrates a striking advance in developing monovalent ion-selective channels and has implications in sensing, energy storage, and separation technologies.
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Graphene quantum dot (GQD) is one of the youngest superstars of the carbon family. Since its emergence in 2008, GQD has attracted a great deal of attention due to its unique optoelectrical properties. Non-zero bandgap, the ability to accommodate functional groups and dopants, excellent dispersibility, highly tunable properties, and biocompatibility are among the most important characteristics of GQDs. To date, GQDs have displayed significant momentum in numerous fields such as energy devices, catalysis, sensing, photodynamic and photothermal therapy, drug delivery, and bioimaging. As this field is rapidly evolving, there is a strong need to identify the emerging challenges of GQDs in recent advances, mainly because some novel applications and numerous innovations on the ease of synthesis of GQDs are not systematically reviewed in earlier studies. This feature article provides a comparative and balanced discussion of recent advances in synthesis, properties, and applications of GQDs. Besides, current challenges and future prospects of these emerging carbon-based nanomaterials are also highlighted. The outlook provided in this review points out that the future of GQD research is boundless, particularly if upcoming studies focus on the ease of purification and eco-friendly synthesis along with improving the photoluminescence quantum yield and production yield of GQDs.
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Grafite , Nanoestruturas , Pontos Quânticos , Carbono , Sistemas de Liberação de MedicamentosRESUMO
Ammonia gas sensors have always received significant attention as robust platforms for emission control, food safety, and monitoring human exhaled breath for the early diagnosis of diseases such as dysfunction of the kidney and liver. This study explores the development of a microwave-based split-ring resonator (SRR) sensor with enhanced sensitivity to detect ammonia gas at low concentrations. The sensor is based on a nanocomposite fabricated by incorporating 10 wt% of graphene oxide (GO) into polyaniline (PANI) via the in-situ polymerization of aniline monomers over the surface of the GO sheets. The addition of GO to PANI results in a high sensitivity of 0.038 dB ppm-1 for low concentrations (1-25 ppm) and 0.0045 dB ppm-1 for high concentrations (> 25 ppm) of ammonia gas, in a 150-400 s time interval at room temperature. The prepared sensor can selectively sense ammonia gas in the presence of other higher concentrations of hazardous gases and a wide range of relative humidity levels (15-90%). The response signal is repeatable after 30 days with less than 0.32% deviation. The developed low-cost and robust sensor has the potential to monitor ammonia gas in various applications, including medical, environmental, food, and agricultural sectors.
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Amônia , Micro-Ondas , Compostos de Anilina , Grafite , HumanosRESUMO
Up now, the communication between brains of different humans or animals has been confirmed and confined by the sensory medium and motor facilities of body. Recently, direct brain-to-brain communication (DBBC) outside the conventional five senses has been verified between animals and humans. Nevertheless, no empirical studies or serious discussion have been performed to elucidate the mechanism behind this process. The validation of DBBC has been documented via recording similar pattern of action potentials occurring in the brain cortex of two animals. With regard to action potentials in brain neurons, the magnetic field resulting from the action potentials created in neurons is one of the tools where the brain of one animal can affect the brain of another. It has been shown that different animals, even humans, have the power to understand the magnetic field. Cryptochrome, which exists in the retina and in different regions of the brain, has been confirmed to be able to perceive magnetic fields and convert magnetic fields to action potentials. Recently, iron particles (Fe3O4) believed to be functioning as magnets have been found in various parts of the brain, and are postulated as magnetic field receptors. Newly developed supersensitive magnetic sensors made of iron magnets that can sense the brain's magnetic field have suggested the idea that these Fe3O4 particles or magnets may be capable of perceiving the brain's extremely weak magnetic field. The present study suggests that it is possible the extremely week magnetic field in one animal's brain to transmit vital and accurate information to another animal's brain.
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Decoding behavioral aspects associated with the water molecules in confined spaces such as an interlayer space of two-dimensional nanosheets is key for the fundamental understanding of water-matter interactions and identifying unexpected phenomena of water molecules in chemistry and physics. Although numerous studies have been conducted on the behavior of water molecules in confined spaces, their reach stops at the properties of the planar ice-like formation, where van der Waals interactions are the predominant interactions and many questions on the confined space such as the possibility of electron exchange and excitation state remain unsettled. We used density functional theory and reactive molecular dynamics to reveal orbital overlap and induction bonding between water molecules and graphene sheets under much less pressure than graphene fractures. Our study demonstrates high amounts of charge being transferred between water and the graphene sheets, as the interlayer space becomes smaller. As a result, the inner face of the graphene nanosheets is functionalized with hydroxyl and epoxy functional groups while released hydrogen in the form of protons either stays still or traverses a short distance inside the confined space via the Grotthuss mechanism. We found signatures of a new hydrolysis mechanism in the water molecules, i.e. mechanical hydrolysis, presumably responsible for relieving water from extremely confined conditions. This phenomenon where water reacts under extreme confinement by disintegration rather than forming ice-like structures is observed for the first time, illustrating the prospect of treating ultrafine porous nanostructures as a driver for water splitting and material functionalization, potentially impacting the modern design of nanofilters, nanochannels, nano-capacitators, sensors, and so on.
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Over 27 million individuals are affected every year worldwide with central nervous system (CNS) injuries. These injuries include but are not limited to traumatic brain injury (TBI) and spinal cord injury (SCI). CNS injuries remain a significant public health concern which demands reliable tools for rapid, on-sight, on-field, and point-of-care diagnostic (POC) solutions. To address these challenges, we developed a low-cost, open-source, hand-held, portable, and POC detection technology, termed as MicroDrop (µDrop), which can simultaneously detect up to eight target biomolecules and display results in both analog and digital formats. The data acquired is stored wirelessly in a cloud server for further investigation and statistical analysis. Multiplexing capability of µDrop and immuno-biosensors detects and quantifies Cleaved-Tau Protein (C-Tau) and Neuron-Filament (NFL) proteins in the blood of TBI patients. Immuno-biosensors rapidly sense the two target proteins in less than 30 min, with µDrop and a conventional potentiostat. C-Tau and NFL were selectively detected with µDrop within the dynamic range of 10 pg/mL - 100 ng/mL and the sensitivity range of 47 µA/pg mm2 - 65 µA/pg mm2. Comparing the biosensing performance with enzyme-linked immunosorbent assays (ELISA) shows that the immuno-biosensors combined with µDrop could successfully differentiate between clinical controls and injured patients.
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Técnicas Biossensoriais , Lesões Encefálicas Traumáticas , Biomarcadores , Lesões Encefálicas Traumáticas/diagnóstico , Humanos , Neurônios , Proteínas tauRESUMO
3D printing of cementitious materials holds a great promise for construction due to its rapid, consistent, modular, and geometry-controlled ability. However, its major drawback is low cohesion in the interlayer region. Herein, we report a combined experimental and computational approach to understand and control fabrication of 3D-printed cementitious materials with significantly enhanced interlayer strength using multimaterial 3D printing, in which the composition, function, and structure of the materials are programmed. Our results show that the intrinsic low interlayer cohesion is caused by excess moisture and time lag that block the majority of valuable interactions in the interlayer zone between the adjacent cement matrices. As a remedy, a thin epoxy layer is introduced as an intermediator between the adjacent extruded layers, both to improve the interlayer cohesion and to extend the possible time delay between printed adjacent layers. Our ab initio calculations demonstrate that an orbital overlap between the calcium ions, as the main electrophilic part of the cement structure, and the hydroxyl groups, as the nucleophilic part of the epoxy, create strong interfacial absorption sites. These electronic absorptions lead to several iono-covalent bonds between the cement matrix and epoxy, leading to significant improvements in tensile, shear, and compressive strengths as well as ductility of the 3D-printed composites. This is verified by our experimental data, which showed an average of 84% improvement in interlayer bonding. The upward augmentation of interlayer bonding helps 3D printing cementitious material to overcome their intrinsic limitation of weak interlayer cohesion, thereby mitigating/eliminating the key bottleneck of additive manufacturing in constructing materials.
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Transparent electromagnetic interference (EMI) shields are increasingly in demand for medical, military, wireless networks, aerospace electronics, and navigation control systems. To date, researchers have mixed pristine and/or doped conductive polymers with carbon allotropes and metallic fillers to increase the total shielding effectiveness, compromising the transparency, amount of the materials used, and weight of the shields. Obtaining cost-effective and transparent EMI shields without the need to incorporate fillers is extremely desirable. Herein, we implement a design strategy for fabricating a gigahertz (GHz) highly transparent shield made of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The total EMI shielding effectiveness of 15 dB is achieved in the X-band frequency range for a 50 nm ultrathin film with a high transparency of 97.1%. The fabricated filler-free EMI shield holds a record thickness-specific shielding figure-of-merit of 300 dB µm-1-far exceeding the best values for micron-thick silver-, carbon-, and MXene-based composite material shields-with even a higher transparency. The feasibility of the developed filler-free shield for large-scale applications is validated by its integration into a cell phone display glass, as a prototype, in which the EMI shielding effectiveness elevates to 18.3 dB.