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Interactions of graphene oxide (GO) with an ex vivo rat heart and its coronary vessels have not been studied yet. Moreover, the conflicting data on the "structure-properties" relationships do not allow for biomedical applications of GO. Herein, we study the impact of GO on the ex vivo isolated rat heart, normotensive and hypertensive, under the working heart and the constant-pressure perfusion (Langendorff) regimes. Four structural GO variants of the following initial morphology were used: few-layer (below 10-layer) GO1, O < 49%; predominantly single-layer GO2, O = 41-50%; 15-20-layer GO3, O < 11%; and few-layer (below 10-layer) NH4 +-functionalized GO4, O < 44%, N = 3-6%. The aqueous GO dispersions, sonicated and stabilized with bovine serum albumin in Krebs-Henseleit-like solution-uniformized in terms of the particle size-were eventually size-monodisperse as revealed by dynamic light scattering. To study the cardiotoxicity mechanisms of GO, histopathology, Raman spectroscopy, analysis of cardiac parameters (coronary and aortic flows, heart rate, aortic pressure), and nitric oxide (NO-)-dependent coronary flow response to bradykinin (blood-vessel-vasodilator) were used. GO1 (10 mg/L) exerted no effects on cardiac function and preserved an increase in coronary flow in response to bradykinin. GO2 (10 mg/L) reduced coronary flow, aortic pressure in normotensive hearts, and coronary flow in hypertensive hearts, and intensified the response to bradykinin in normal hearts. GO3 (10 mg/L) reduced all parameters in hypertensive hearts and coronary response to bradykinin in normal hearts. At higher concentrations (normotensive hearts, 30 mg/L), the coronary response to bradykinin was blocked. GO4 (10 mg/L) reduced the coronary flow in normal hearts, while for hypertensive hearts, all parameters, except the coronary flow, were reduced and the coronary response to bradykinin was blocked. The results showed that a low number of GO layers and high O-content were safer for normal and hypertensive rat hearts. Hypertensive hearts deteriorated easier upon perfusion with low-O-content GOs. Our findings support the necessity of strict control over the GO structure during organ perfusion and indicate the urgent need for personalized medicine in biomedical applications of GO.
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Although F-Containing molecules and macromolecules are often used in molecular biology to increase the binding with Lewis acidic groups by introducing favorable C-F dipoles, there is virtually no experimental evidence and limited understanding of the nature of these interactions, especially their role in synthetic polymeric materials. These studies elucidate the molecular origin of inter- and intra-Chain interactions responsible for self-healing of F-Containing copolymers composed of pentafluorostyrene and n-butyl acrylate units (p(PFS/nBA). Guided by dynamic surface oscillating force (SOF) and spectroscopic measurements supported by molecular dynamics (MD) simulations, these studies show that the reformation of σ-σ orbitals in -C-F of PFS and CH3CH2- of nBA units enables the recovery of entropic energy via fluorophilic-σ-lock van der Waals forces when PFS/nBA molar ratios are ~50/50. The strength of these interactions determined experimentally for self-healable PFS/nBA compositions is in the order ~0.3â kcal/mol which primarily comes from fluorophilic-σ-lock (~70 %) contributions. These interactions are significantly diminished for non-self-healable counterparts. Strongly polarized -C-F σ orbitals create lateral dipolar forces enhancing the affinity towards -C-H orbitals, facilitating energetically favorable interactions. Entropic recovery driven by non-Covalent bonding offers a valuable tool in designing materials with unique functionalities, particularly self-healable batteries and energy storage devices.
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It is well-established that interfaces play critical roles in biological and synthetic processes. Aside from significant practical applications, the most accessible and measurable quantity is interfacial tension, which represents a measure of the energy required to create or rejoin two surfaces. Owing to the fact that interfacial processes are critical in polymeric materials, this review outlines recent advances in dynamic interfacial processes involving physics and chemistry targeting self-healing. Entropic interfacial energies stored during damage participate in the recovery, and self-healing depends upon copolymer composition and monomer sequence, monomer molar ratios, molecular weight, and polymer dispersity. These properties ultimately impact chain flexibility, shape-memory recovery, and interfacial interactions. Self-healing is a localized process with global implications on mechanical and other properties. Selected examples driven by interfacial flow and shape memory effects are discussed in the context of covalent and supramolecular rebonding targeting self-healable materials development.
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Causal analysis plays a significant role in physics, chemistry, and biology. Dynamics of complex (bio)molecular and nanosystems, from the microscopic to the macroscopic scale, are characterized by time-dependent vectors such as positions, forces, momenta, angular momenta, or torques. Identification and analysis of causal relationships between these time-dependent signals is an important problem in the multidimensional time-series analysis and is of great practical importance in describing the properties of such dynamical systems, and to understanding their functionality. For linear stochastic systems characterized by multidimensional scalar signals, Granger proposed a simple procedure to detect causal relationships, called Granger causality. In this study we extended this formalism to vector signals representing physical vector quantities. For this purpose, we used quaternion algebra, where vector signals are treated as time-dependent quaternions. The developed analytical model is based on the autoregressive formalism. This formalism (Q-MVAR) and its numerical implementation were validated using two simple dynamic models: a rigid body model represented by a benzenelike molecular fragment, interacting with a short-range harmonic potential with a wall, as well as a system of three model atomic balls moving inside a soft spherical surface and interacting with long range electrostatic forces. Although the motivation to these studies was the analysis of classical motions in complex (bio)molecular systems, described with a mechanical model and based on molecular dynamics (MD) simulations, in particular coarse-grained ones, it should be noted that the developed extended formalism can be applied to any system composed of many rigid elements that interact with arbitrary potentials and are characterized by complex internal motions. A description of the detailed procedure for calculating causality measures is provided in the Appendices of the Supplemental Material. This formalism and the prototype of its numerical implementation can be further developed and applied in many different fields of physical, natural, and engineering sciences.
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The incidence of thyroid nodules (TNs) is estimated at 36.5% and 23% in females and males, respectively. A single thyroid nodule is usually detected during ultrasound assessment in patients with symptoms of thyroid dysfunction or neck mass. TNs are classified as benign tumours (non-malignant hyperplasia), benign neoplasms (e.g., adenoma, a non-invasive follicular tumour with papillary nuclear features) or malignant carcinomas (follicular cell-derived or C-cell derived). The differential diagnosis is based on fine-needle aspiration biopsies and cytological assessment (which is burdened with the bias of subjectivity). Raman spectroscopy (RS) is a laser-based, semiquantitative technique which shows for oscillations of many chemical groups in one label-free measurement. RS, through the assessment of chemical content, gives insight into tissue state which, in turn, allows for the differentiation of disease on the basis of spectral characteristics. The purpose of this study was to report if RS could be useful in the differential diagnosis of TN. The Web of Science, PubMed, and Scopus were searched from the beginning of the databases up to the end of June 2023. Two investigators independently screened key data using the terms "Raman spectroscopy" and "thyroid". From the 4046 records found initially, we identified 19 studies addressing the differential diagnosis of TNs applying the RS technique. The lasers used included 532, 633, 785, 830, and 1064 nm lines. The thyroid RS investigations were performed at the cellular and/or tissue level, as well as in serum samples. The accuracy of papillary thyroid carcinoma detection is approx. 90%. Furthermore, medullary, and follicular thyroid carcinoma can be detected with up to 100% accuracy. These results might be biased with low numbers of cases in some research and overfitting of models as well as the reference method. The main biochemical changes one can observe in malignancies are as follows: increase of protein, amino acids (like phenylalanine, tyrosine, and tryptophan), and nucleic acid content in comparison with non-malignant TNs. Herein, we present a review of the literature on the application of RS in the differential diagnosis of TNs. This technique seems to have powerful application potential in thyroid tumour diagnosis.
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Adenocarcinoma Folicular , Neoplasias de la Tiroides , Nódulo Tiroideo , Masculino , Femenino , Humanos , Nódulo Tiroideo/diagnóstico por imagen , Nódulo Tiroideo/patología , Espectrometría Raman , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/patología , Adenocarcinoma Folicular/patologíaRESUMEN
Graphene oxide's (GO) intravascular applications and biocompatibility are not fully explored yet, although it has been proposed as an anticancer drug transporter, antibacterial factor or component of wearable devices. Bivalent cations and the number of particles' atom layers, as well as their structural oxygen content and pH of the dispersion, all affect the GO size, shape, dispersibility and biological effects. Bovine serum albumin (BSA), an important blood plasma protein, is expected to improve GO dispersion stability in physiological concentrations of the precipitating calcium and magnesium cations to enable effective and safe tissue perfusion. METHODS: Four types of GO commercially available aqueous dispersions (with different particle structures) were diluted, sonicated and studied in the presence of BSA and physiological cation concentrations. Nanoparticle populations sizes, electrical conductivity, zeta potential (Zetasizer NanoZS), structure (TEM and CryoTEM), functional groups content (micro titration) and dispersion pH were analyzed in consecutive preparation stages. RESULTS: BSA effectively prevented the aggregation of GO in precipitating concentrations of physiological bivalent cations. The final polydispersity indexes were reduced from 0.66-0.91 to 0.36-0.43. The GO-containing isotonic dispersions were stable with the following Z-ave results: GO1 421.1 nm, GO2 382.6 nm, GO3 440.2 nm and GO4 490.1 nm. The GO behavior was structure-dependent. CONCLUSION: BSA effectively stabilized four types of GO dispersions in an isotonic dispersion containing aggregating bivalent physiological cations.
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BACKGROUND: Aortic pulse wave velocity (PWV) predicts cardiovascular events (CVEs) and total mortality (TM), but previous studies proposing actionable PWV thresholds have limited generalizability. This individual-participant meta-analysis is aimed at defining, testing calibration, and validating an outcome-driven threshold for PWV, using 2 populations studies, respectively, for derivation IDCARS (International Database of Central Arterial Properties for Risk Stratification) and replication MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease Health Survey - Copenhagen). METHODS: A risk-carrying PWV threshold for CVE and TM was defined by multivariable Cox regression, using stepwise increasing PWV thresholds and by determining the threshold yielding a 5-year risk equivalent with systolic blood pressure of 140 mm Hg. The predictive performance of the PWV threshold was assessed by computing the integrated discrimination improvement and the net reclassification improvement. RESULTS: In well-calibrated models in IDCARS, the risk-carrying PWV thresholds converged at 9 m/s (10 m/s considering the anatomic pulse wave travel distance). With full adjustments applied, the threshold predicted CVE (hazard ratio [CI]: 1.68 [1.15-2.45]) and TM (1.61 [1.01-2.55]) in IDCARS and in MONICA (1.40 [1.09-1.79] and 1.55 [1.23-1.95]). In IDCARS and MONICA, the predictive accuracy of the threshold for both end points was ≈0.75. Integrated discrimination improvement was significant for TM in IDCARS and for both TM and CVE in MONICA, whereas net reclassification improvement was not for any outcome. CONCLUSIONS: PWV integrates multiple risk factors into a single variable and might replace a large panel of traditional risk factors. Exceeding the outcome-driven PWV threshold should motivate clinicians to stringent management of risk factors, in particular hypertension, which over a person's lifetime causes stiffening of the elastic arteries as waypoint to CVE and death.
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Enfermedades Cardiovasculares , Hipertensión , Rigidez Vascular , Humanos , Análisis de la Onda del Pulso/efectos adversos , Aorta , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Hipertensión/diagnóstico , Hipertensión/epidemiología , Hipertensión/complicaciones , Arterias , Factores de Riesgo , Rigidez Vascular/fisiologíaRESUMEN
Background: Guidelines recommend patients with anaphylaxis are prescribed epinephrine autoinjectors (EAI), carry the EAI with them, and are referred to an allergist. There also are barriers to EAI administration, such as acquiring the medication, having it available, recognizing when to use it, and administering it appropriately. Objective: The objective was to describe how often patients with anaphylaxis discharged from the emergency department (ED) receive an EAI prescription and allergist referral; also, to assess the frequency of EAI pick-up by the patient from the outpatient pharmacy, out-of-pocket cost, change in EAI device during dispensing, and if patient training on EAI use and allergist follow-up occurred. Patient-specific factors associated with the occurrence of these variables were investigated. Methods: This was a retrospective, observational study of adult and pediatric ED patients who presented with anaphylaxis between July and December 2020. Data were collected from medical records and telephone calls to outpatient pharmacies and included patient demographics; ED treatment; EAI prescribing, EAI pick-up from the outpatient pharmacy, and cost; device changes; EAI training; and allergist referral and follow-up. Data are presented descriptively, and bivariate analyses were used for comparisons between patient-specific factors and incidence of EAI prescribing, patient pick-up, and allergist referral. Results: A total of 102 patients were included; mean age ± standard deviation 34 ± 7 years, 52% were < 18 years of age; and 54% had a history of allergy and/or anaphylaxis. EAI prescribing occurred in 79% of the patients. Of these, 71% picked up the EAI from the outpatient pharmacy, the median cost to the patient was $5 (range, $0-$379), 18% had an EAI device change at dispensing, and 23% received EAI training. Allergist referral occurred in 22%, and 28% followed up with an allergist within 60 days. Presenting symptoms of mucosal edema and respiratory stridor were associated with the occurrence of EAI prescribing. Presenting symptoms of respiratory wheezing, hoarseness, throat itching, skin flushing and allergist referral from the ED were associated with the occurrence of EAI pick-up from the outpatient pharmacy. Conclusion: Overall, 79% of ED patients with anaphylaxis had an EAI prescribed and 22% had an allergist referral; 71% picked up the EAI from the outpatient pharmacy, EAI dispensing changes occurred, and training was infrequent. Collaboration between emergency medicine clinicians, allergists, and pharmacists is needed to streamline treatment and follow-up.
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Anafilaxia , Medicina de Emergencia , Adulto , Niño , Humanos , Anafilaxia/diagnóstico , Anafilaxia/tratamiento farmacológico , Servicio de Urgencia en Hospital , Alergólogos , Epinefrina/uso terapéuticoRESUMEN
Commodity copolymers offer many useful applications, and their durability is critical in maintaining desired functions and retaining sustainability. These studies show that primarily alternating styrene/n-butyl acrylate [p(Sty/nBA)] copolymers self-heal without external intervention when monomer molar ratios are within the 45:55-53:47 range. This behavior is attributed to the favorable interchain interactions between aliphatic nBA side groups being sandwiched by aromatic rings forming ring-and-lock associations driven by pi-sigma-pi (π-σ-π) interactions. Guided by molecular dynamics (MD) simulations combined with spectroscopic and thermomechanical analysis, the ring-and-lock interchain van der Waals forces between π orbitals of aromatic rings and sigma components of aliphatic side groups are responsible for self-healing. Despite the frequent occurrence of these interactions in biological systems (proteins, nucleic acids, lipids, and polysaccharides), these largely unexplored weak and ubiquitous molecular forces between the soft acid aliphatic and soft base aromatic electrons may be valuable assets in the development of polymeric materials with sustainable properties.
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Osteosarcomas arising within the pterygomaxillary/infratemporal fossa region are rare among the pediatric population. Survival rates are most influenced by tumor resection with negative margins, which can be dependent on surgical accessibility of the tumor site. The pterygomaxillary/infratemporal fossa location poses several challenges to safe and adequate tumor resection, including proximity of the facial nerve and great vessels and scarring associated with traditional transfacial approaches. In this article, we present the case of a 6-year-old boy with an osteosarcoma of the left pterygomaxillary/infratemporal fossa region successfully managed with an "oncoplastic" approach, incorporating the use of CAD/CAM and mixed reality technologies.
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BACKGROUND: The SARS-CoV-2 pandemic is a worldwide challenge. The CRIT-CoV-U pilot study generated a urinary proteomic biomarker consisting of 50 peptides (COV50), which predicted death and disease progression from SARS-CoV-2. After the interim analysis presented for the German Government, here, we aimed to analyse the full dataset to consolidate the findings and propose potential clinical applications of this biomarker. METHODS: CRIT-CoV-U was a prospective multicentre cohort study. In eight European countries (Austria, France, Germany, Greece, North Macedonia, Poland, Spain, and Sweden), 1012 adults with PCR-confirmed COVID-19 were followed up for death and progression along the 8-point WHO scale. Capillary electrophoresis coupled with mass spectrometry was used for urinary proteomic profiling. Statistical methods included logistic regression and receiver operating characteristic curve analysis with a comparison of the area under curve (AUC) between nested models. Hospitalisation costs were derived from the care facility corresponding with the Markov chain probability of reaching WHO scores ranging from 3 to 8 and flat-rate hospitalisation costs adjusted for the gross per capita domestic product of each country. FINDINGS: From June 30 to Nov 19, 2020, 228 participants were recruited, and from April 30, 2020, to April 14, 2021, 784 participants were recruited, resulting in a total of 1012 participants. The entry WHO scores were 1-3 in 445 (44%) participants, 4-5 in 529 (52%) participants, and 6 in 38 (4%) participants; and of all participants, 119 died and 271 had disease progression. The odds ratio (OR) associated with COV50 in all 1012 participants for death was 2·44 (95% CI 2·05-2·92) unadjusted and 1·67 (1·34-2·07) when adjusted for sex, age, BMI, comorbidities, and baseline WHO score; and for disease progression, the OR was 1·79 (1·60-2·01) when unadjusted and 1·63 (1·41-1·91) when adjusted (p<0·0001 for all). The predictive accuracy of the optimised COV50 thresholds was 74·4% (71·6-77·1%) for mortality (threshold 0·47) and 67·4% (64·4-70·3%) for disease progression (threshold 0·04). When adjusted for covariables and the baseline WHO score, these thresholds improved AUCs from 0·835 to 0·853 (p=0·033) for death and from 0·697 to 0·730 (p=0·0008) for progression. Of 196 participants who received ambulatory care, 194 (99%) did not reach the 0·04 threshold. The cost reductions associated with 1 day less hospitalisation per 1000 participants were million Euro (M) 0·887 (5-95% percentile interval 0·730-1·039) in participants at a low risk (COV50 <0·04) and M2·098 (1·839-2·365) in participants at a high risk (COV50 ≥0·04). INTERPRETATION: The urinary proteomic COV50 marker might be predictive of adverse COVID-19 outcomes. Even in people with mild-to-moderate PCR-confirmed infections (WHO scores 1-4), the 0·04 COV50 threshold justifies earlier drug treatment, thereby potentially reducing the number of days in hospital and associated costs. FUNDING: German Federal Ministry of Health.
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COVID-19 , Adulto , Biomarcadores , COVID-19/diagnóstico , Estudios de Cohortes , Progresión de la Enfermedad , Humanos , Proyectos Piloto , Estudios Prospectivos , Proteómica , SARS-CoV-2RESUMEN
Electrically accelerated self-healable poly(ionic liquids) copolymers that exhibit resistor-capacitor (RC) circuit properties are developed. At low alternating current (AC) frequencies these materials behave as a resistor (R), whereas at higher frequencies as a capacitor (C). These properties are attributed to a combination of dipolar and electrostatic interactions in (1-[(2-methacryloyloxy)ethyl]-3-butylimidazolium bis(trifluoromethyl-sulfonyl)imide) copolymerized with methyl methacrylate (MMA) monomers to form p(MEBIm-TSFI/MMA)] copolymers. When the monomer molar ratio (MEBIm-TSFI:MMA) is 40/60, these copolymers are capable of undergoing multiple damage-repair cycles and self-healing is accelerated by the application of alternating 1.0-4.0 V electric field (EF). Self-healing in the absence of EFs is facilitated by van der Waals (vdW) interactions, but the application of AC EF induces back and forth movement of charges against the opposing force that result in dithering of electrostatic dipoles giving rise to interchain physical crosslinks. Electrostatic inter- and intrachain interactions facilitated by copolymerization of ionic liquid monomers with typically dielectric acrylic-based monomers result in enhanced cohesive energy densities that accelerate the recovery of vdW forces facilitating self-healing. Incorporating ionic liquids into commodity polymers offers promising uses as green conducting solid polyelectrolytes in self-healable energy storage, energy-harvesting devices, and many other applications.
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Líquidos Iónicos , Iones , Polimerizacion , Polímeros , Electricidad EstáticaRESUMEN
ABSTRACT: Hebisz, RG, Hebisz, P, and Zaton, MW. Heart rate variability after sprint interval training in cyclists and implications for assessing physical fatigue. J Strength Cond Res 36(2): 558-564, 2022-This study evaluated the time- and frequency-domain indexes of heart rate variability (HRV) during sprint interval exercise test (SIXT) and identify the onset of fatigue by HRV concurrent with changes in average (Pavg) and peak (Ppeak) power output, total oxygen uptake (VÌo2tou), and blood hydrogen (H+) and lactate (La-) concentrations. Twenty-seven cyclists performed 4 sets of SIXT in which each set consisted of four 30-second maximal sprints interspersed with 90 seconds of low-intensity cycling. Each set was separated by 25-40 minutes of recovery. Before beginning each set, HRV was analyzed by time (mean normal-to-normal RR intervals [RRNN], SD of normal-to-normal RR intervals [SDNN], and square root of the mean squared difference between successive normal-to-normal RR intervals [RMSSD]) and frequency (total spectral power [T] and very low- [VLF], low- [LF], and high-frequency [HF] spectral power) domain methods. Pavg, Ppeak, and VÌo2tou were recorded in each set, and H+ and La- were measured after each set. RRNN, SDNN, and VLF decreased in the second set, whereas all time and frequency indexes of HRV decreased in the third and fourth set. Pavg and H+ decreased, while VÌo2tou increased in the fourth set. Ppeak decreased in the second, third, and fourth set. Correlations were found between the changes in the time and frequency indexes of HRV with H+, La-, and VÌo2tou. The results indicate that HRV does not reflect the onset of physical fatigue in SIXT as was observed in Pavg and no correlation was found between the changes in HRV with Pavg and Ppeak.
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Entrenamiento de Intervalos de Alta Intensidad , Ciclismo , Prueba de Esfuerzo , Fatiga , Frecuencia Cardíaca , HumanosRESUMEN
Coordinated medical care offered in Poland for patients suffering from neurofibromatosis type 1 and related RASopathies combines complex multispecialty consultation with permanent supervision and the patient's oriented longitudinal care. Neurofibromatosis type 1 is one of the most common single gene disorders in the global population, observed in 1 out of 2500-3000 live births. It is a primary neoplasia disease with 100% penetration of the gene mutation but remarkable age-dependent onset of different disease signs and symptoms, outstanding clinical heterogeneity between patients even in one family and lack of genotype-phenotype correlation, a high rate of spontaneous mutation exceeding 50%, and multiple comorbidities among which increased risk of malignancy is the most important. Medical practice proved that not only patient-oriented complex but also coordinated care provided in centers of competence is indispensable for patients and the families and provides a sense of medical security to them in conjunction with public health costs rationalization.
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Tularemia is a disease caused by Francisella tularensis-gram-negative coccobacillus. The ulceroglandular type characterized by skin ulcers and painful regional adenopathy is recognized as the most common. A 1-year-old patient was admitted with severe normocytic anemia, high fever and hepatosplenomegaly. A nonspecific lesion in the axillary region with a homogenous nodal reaction was found, combined with a history of a tick-bite in the pectoral muscle. Primary differentiation included leukemia, lymphoma, mononucleosis, borrelial lymphoma and simple abscess. All of the above were excluded. A further search for diagnosis focused on tick-borne diseases: TIBOLa or anaplasmosis. The ulceroglandular tularemia was eventually confirmed serologically. Besides the fact that tularemia is a rare diagnosis nowadays, it is still necessary to include this disease in the differentiation of a nonresolving tick-bite abscess with lymphadenopathy. Diagnostic vigilance is the key to effective treatment because other obvious symptoms such as severe anemia might delay the diagnosis.
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Although dipolar forces between copolymer chains are relatively weak, they result in ubiquitous inter- and/or intramolecular interactions which are particularly critical in achieving the mechanical integrity of polymeric materials. In this study, a route is developed to obtain self-healable properties in thermoplastic copolymers that rely on noncovalent dipolar interactions present in essentially all macromolecules and particularly fluorine-containing copolymers. The combination of dipolar interactions between CâF and CâO bonds as well as CH2 /CH3 entities facilitates self-healing without external intervention. The presence of dipole-dipole, dipole-induced dipole, and induced-dipole induced dipole interactions leads to a viscoelastic response that controls macroscopic autonomous multicycle self-healing of fluorinated copolymers under ambient conditions. Energetically favorable dipolar forces attributed to monomer sequence and monomer molar ratios induces desirable copolymer tacticities, enabling entropic energy recovery stored during mechanical damage. The use of dipolar forces instead of chemical or physical modifications not only eliminates additional alternations enabling multiple damage-repair cycles but also provides further opportunity for designing self-healable commodity thermoplastics. These materials may offer numerous applications, ranging from the use in electronics, ion batteries, H2 fuel dispense hoses to self-healable pet toys, packaging, paints and coatings, and many others.
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Known for their adaptability to surroundings, capability of transport control of molecules, or the ability of converting one type of energy to another as a result of external or internal stimuli, responsive polymers play a significant role in advancing scientific discoveries that may lead to an array of diverge applications. This review outlines recent advances in the developments of selected commodity polymers equipped with stimuli-responsiveness to temperature, pH, ionic strength, enzyme or glucose levels, carbon dioxide, water, redox agents, electromagnetic radiation, or electric and magnetic fields. Utilized diverse applications ranging from drug delivery to biosensing, dynamic structural components to color-changing coatings, this review focuses on commodity acrylics, epoxies, esters, carbonates, urethanes, and siloxane-based polymers containing responsive elements built into their architecture. In the context of stimuli-responsive chemistries, current technological advances as well as a critical outline of future opportunities and applications are also tackled.
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Polímeros de Estímulo Receptivo , Sistemas de Liberación de Medicamentos , Polímeros , TemperaturaRESUMEN
Nanoparticles (NPs) are released from orthopedic and neurosurgical prostheses and can interact with a number of blood components once in the bloodstream. Potential toxic effects of Co and Cr NPs on blood platelets have not been thoroughly investigated. The aim of this study was to analyze the effect of Co and Cr NPs on platelet function in vitro. The ability of the tested NPs to induce platelet activation and aggregation was measured using light transmission aggregometry, flow cytometry, and quartz crystal balance with dissipation (QCM-D). This was confirmed by transmission electron microscopy (TEM), scanning electron microscopy, and optical and immunofluorescence microscopy. Perfusion of QCM-D sensor crystals with platelet-rich-plasma in the presence of Co 28 nm, CoO 50 nm, Co2O3 50 nm, Co3O4 30-50nm, Cr 35-45nm, Cr2O3 60 nm NPs (0.5-5.0 µg/mL) resulted in significant changes in frequency and dissipation, indicating that these NPs caused platelet microaggregation. Transmission electron microscopy also revealed that Cr NPs led to platelet swelling and lysis. Our study shows that both Co and Cr NPs affect platelet function in vitro with two distinct mechanisms. While Co NPs result in standard platelet aggregation, Cr NPs cause both platelet aggregation and decreased platelet membrane integrity and lysis. Based on these findings, monitoring serum NP levels and platelet-mediated hemostasis can be advised in patients with metal-on-metal Co-Cr prostheses.
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Plaquetas/efectos de los fármacos , Cromo/toxicidad , Cobalto/toxicidad , Nanopartículas del Metal/toxicidad , Agregación Plaquetaria/efectos de los fármacos , Cromo/química , Cobalto/química , Femenino , Citometría de Flujo , Humanos , Nanopartículas del Metal/química , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Microscopía FluorescenteRESUMEN
Previous studies have shown that copolymer compositions can significantly impact self-healing properties. This was accomplished by enhancement of van der Waals (vdW) forces which facilitate self-healing in relatively narrow copolymer compositional range. In this work we report the acceleration of self-healing in alternating/random hydrophobic acrylic-based copolymers in the presence of confined water molecules. Under these conditions competing vdW interactions do not allow H2O-diester H-bonding, thus forcing nBA side groups to adapt L-shape conformations, generating stronger dipole-dipole interactions resulting in shorter inter-chain distances compared to 'key-and-lock' associations without water. The perturbation of vdW forces upon mechanical damage in the presence of controllable amount of confined water is energetically unfavorable leading the enhancement of self-healing efficiency of hydrophobic copolymers by a factor of three. The concept may be applicable to other self-healing mechanisms involving reversible covalent bonding, supramolecular chemistry, or polymers with phase-separated morphologies.
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The main goal of this study was to draw the attention of physicians to commonly undisclosed risk of breast cancer (BrCa) in women suffering from neurofibromatosis type 1 (NF-1), which is 5-fold higher than in the general population. NF-1 related BrCa arises earlier (< 50 years) and is more advanced, with an increased mortality. NF-1 is one of the most frequent monogenic diseases worldwide and a tumor predisposition syndrome. The Nf1 gene is an important negative regulator of the Ras oncogene and belongs to the family of the 12 the most important BrCa predisposition genes. Planning introduction of BrCa screening guidelines for NF-1 women in Poland we started with assessment of BrCa risk awareness and current preventive practices in this population by a survey published in an open access internet profile dedicated exclusively to patients with NF-1 in Poland, with 1928 participants. As a result, we revealed that the awareness of this specific risk was declared by only 30% out of 138 responders, and only 21% of them received this information from medical professionals. In all 4 (2.89%) women suffering from BrCa the cancer was diagnosed before the 50th year of age. It exceeds significantly the expected prevalence of BrCa in the general population of Polish women. We conclude that the limited awareness of NF-1 related BrCa risk in Polish patients warrants the educational effort directed both to the NF-1 patients by professional counseling and to the medical community, in order to increase the efficacy of preventive measures and decrease BrCa mortality.