RESUMO
Triggering receptor expressed on myeloid cells-1 (TREM-1) is a pattern recognition receptor and plays a critical role in the immune response. TREM-1 activation leads to the production and release of proinflammatory cytokines, chemokines, as well as its own expression and circulating levels of the cleaved soluble extracellular portion of TREM-1 (sTREM-1). Because patients with sepsis and septic shock show elevated sTREM-1 levels, TREM-1 has attracted attention as an important contributor to the inadequate immune response in this often-deadly condition. Since 2001, when the first blockade of TREM-1 in sepsis was performed, many potential TREM-1 inhibitors have been established in animal models. However, only one of them, nangibotide, has entered clinical trials, which have yielded promising data for future treatment of sepsis, septic shock, and other inflammatory disease such as COVID-19. This review discusses the TREM-1 pathway and important ligands, and highlights the development of novel inhibitors as well as their clinical potential for targeted treatment of various inflammatory conditions.
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Sepse , Choque Séptico , Receptor Gatilho 1 Expresso em Células Mieloides , Animais , Humanos , Citocinas , Sepse/tratamento farmacológico , Receptor Gatilho 1 Expresso em Células Mieloides/metabolismoRESUMO
PURPOSE: Infections are common complications in patients following liver transplantation (LTX). The early diagnosis and prognosis of these infections is an unmet medical need even when using routine biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT). Therefore, new approaches are necessary. METHODS: In a prospective, observational pilot study, we monitored 30 consecutive patients daily between days 0 and 13 following LTX using the 29-mRNA host classifier IMX-BVN-3b that determine the likelihood of bacterial infections and viral infections. True infection status was determined using clinical adjudication. Results were compared to the accuracy of CRP and PCT for patients with and without bacterial infection due to clinical adjudication. RESULTS: Clinical adjudication confirmed bacterial infections in 10 and fungal infections in 2 patients. 20 patients stayed non-infected until day 13 post-LTX. IMX-BVN-3b bacterial scores were increased directly following LTX and decreased until day four in all patients. Bacterial IMX-BVN-3b scores detected bacterial infections in 9 out of 10 patients. PCT concentrations did not differ between patients with or without bacterial, whereas CRP was elevated in all patients with significantly higher levels in patients with bacterial infections. CONCLUSION: The 29-mRNA host classifier IMX-BVN-3b identified bacterial infections in post-LTX patients and did so earlier than routine biomarkers. While our pilot study holds promise future studies will determine whether these classifiers may help to identify post-LTX infections earlier and improve patient management. CLINICAL TRIAL NOTATION: German Clinical Trials Register: DRKS00023236, Registered 07 October 2020, https://drks.de/search/en/trial/DRKS00023236.
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Infecções Bacterianas , Biomarcadores , Transplante de Fígado , Humanos , Transplante de Fígado/efeitos adversos , Projetos Piloto , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Prospectivos , Biomarcadores/sangue , Idoso , Complicações Pós-Operatórias/microbiologia , Complicações Pós-Operatórias/sangue , RNA Mensageiro/genética , Adulto , Proteína C-Reativa/análise , Pró-Calcitonina/sangueRESUMO
PURPOSE OF REVIEW: Direct oral anticoagulants (DOACs) are increasingly prescribed for prevention of thromboembolic events. Thus, trauma care providers are facing a steadily raising number of injured patients on DOACs. RECENT FINDINGS: Despite a predictable pharmacokinetic profile, the resulting plasma levels of trauma patients upon admission and bleeding risks remain uncertain. Therefore, recent guidelines recommend the measurement of DOAC plasma concentrations in injured patients. Alternatively, DOAC specific visco-elastic tests assays can be applied to identify DOAC patients at bleeding risk.Bleeding complications in trauma patients on DOACs are generally higher compared to nonanticoagulated subjects, but comparable to vitamin K antagonists (VKAs). In particular, a traumatic brain injury does not carry an increased risk of intracranial bleeding due to a DOAK intake compared to VKAs. Current studies demonstrated that up to 14% of patients with a hip fracture are on DOACs prior to surgery. However, the majority can be operated safely within a 24h time window without an increased bleeding rate.Specific antagonists facilitate rapid reversal of patients on DOACs. Idarucizumab for dabigatran, and andexanet alfa for apixaban and rivaroxaban have been approved for life threatening bleeding. Alternatively, prothrombin complex concentrate can be used. Dialysis is a potential treatment option for dabigatran and haemoabsorption with special filters can be applied in patients on FXa-inhibitors. SUMMARY: Current guidelines recommend the measurement of DOAC plasma levels in trauma patients. Compared to VKAs, DOACs do not carry a higher bleeding risk. DOAC specific antagonists facilitate the individual bleeding management.
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Anticoagulantes , Ferimentos e Lesões , Humanos , Administração Oral , Anticoagulantes/efeitos adversos , Dabigatrana/efeitos adversos , Hemorragia/induzido quimicamente , Rivaroxabana/efeitos adversos , Tromboembolia/prevenção & controle , Ferimentos e Lesões/tratamento farmacológicoRESUMO
PURPOSE OF REVIEW: The purpose of this review is to consider the clinical value of point-of-care (POC) testing in coagulopathic trauma patients with traumatic brain injury (TBI) and trauma-induced coagulopathy (TIC). RECENT FINDINGS: Patients suffering from severe TBI or TIC are at risk of developing pronounced haemostatic disorders. Standard coagulation tests (SCTs) are insufficient to reflect the complexity of these coagulopathies. Recent evidence has shown that viscoelastic tests (VETs) identify haemostatic disorders more rapidly and in more detail than SCTs. Moreover, VET results can guide coagulation therapy, allowing individualised treatment, which decreases transfusion requirements. However, the impact of VET on mortality remains uncertain. In contrast to VETs, the clinical impact of POC platelet function testing is still unproven. SUMMARY: POC SCTs are not able to characterise the complexity of trauma-associated coagulopathy. VETs provide a rapid estimation of underlying haemostatic disorders, thereby providing guidance for haemostatic therapy, which impacts allogenic blood transfusion requirements. The value of POC platelet function testing to identify platelet dysfunction and guide platelet transfusion is still uncertain.
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Transtornos da Coagulação Sanguínea , Transtornos Hemostáticos , Ferimentos e Lesões , Humanos , Sistemas Automatizados de Assistência Junto ao Leito , Objetivos , Hemorragia/etiologia , Hemorragia/terapia , Transtornos da Coagulação Sanguínea/diagnóstico , Transtornos da Coagulação Sanguínea/etiologia , Transtornos da Coagulação Sanguínea/terapia , Ferimentos e Lesões/complicações , Ferimentos e Lesões/terapia , TromboelastografiaRESUMO
Sepsis is defined as organ failure caused by dysregulated host response to infection. While early antibiotic treatment in patients with acute infection is essential, treating non-infectious patients must be avoided. Current guidelines recommend procalcitonin (PCT) to guide discontinuation of antibiotic treatment. For initiation of therapy, there is currently no recommended biomarker. In this study, we evaluated Host-Derived Delta-like Canonical Notch Ligand 1 (DLL1), a monocyte membrane ligand that has shown promising results in differentiating infectious from non-infectious critically ill patients. Soluble DLL1 levels were measured in plasma samples of six different cohorts. The six cohorts comprise two cohorts with non-infectious inflammatory auto-immune diseases (Hidradenitis Suppurativa, Inflammatory Bowel Disease), one cohort of bacterial skin infection, and three cohorts of suspected systemic infection or sepsis. In total, soluble DLL1 plasma levels of 405 patients were analyzed. Patients were divided into three groups: inflammatory disease, infection, and sepsis (defined according to the Sepsis-3 definition), followed by the evaluation of its diagnostic performance via Area Under the Receiver Operating Characteristics (AUROC) analyses. Patients of the sepsis group showed significantly elevated plasma DLL1 levels compared to patients with uncomplicated infections and sterile inflammation. However, patients with infections had significantly higher DLL1 levels than patients with inflammatory diseases. Diagnostic performance was evaluated and showed better performance for DLL1 for the recognition of sepsis (AUC: 0.823; CI 0.731-0.914) than C-reactive protein (AUC 0.758; CI 0.658-0.857), PCT (AUC 0.593; CI 0.474-0.711) and White Blood Cell count (AUC 0.577; CI 0.46-0.694). DLL1 demonstrated promising results for diagnosing sepsis and was able to differentiate sepsis from other infectious and inflammatory diseases.
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Doenças Transmissíveis , Sepse , Humanos , Ligantes , Calcitonina , Biomarcadores , Sepse/diagnóstico , Pró-CalcitoninaRESUMO
Graph theory allows assessing changes of neuronal connectivity and interactions of brain regions in response to local lesions, e.g., after stroke, and global perturbations, e.g., due to psychiatric dysfunctions or neurodegenerative disorders. Consequently, network analysis based on constructing graphs from structural and functional MRI connectivity matrices is increasingly used in clinical studies. In contrast, in mouse neuroimaging, the focus is mainly on basic connectivity parameters, i.e., the correlation coefficient or fiber counts, whereas more advanced network analyses remain rarely used. This review summarizes graph theoretical measures and their interpretation to describe networks derived from recent in vivo mouse brain studies. To facilitate the entry into the topic, we explain the related mathematical definitions, provide a dedicated software toolkit, and discuss practical considerations for the application to rs-fMRI and DTI. This way, we aim to foster cross-species comparisons and the application of standardized measures to classify and interpret network changes in translational brain disease studies.
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Encéfalo , Neuroimagem , Animais , Encéfalo/fisiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Camundongos , SoftwareRESUMO
Factor XIII (FXIII) is a protein involved in blood clot stabilisation which also plays an important role in processes including trauma, wound healing, tissue repair, pregnancy, and even bone metabolism. Following surgery, low FXIII levels have been observed in patients with peri-operative blood loss and FXIII administration in those patients was associated with reduced blood transfusions. Furthermore, in patients with low FXIII levels, FXIII supplementation reduced the incidence of post-operative complications including disturbed wound healing. Increasing awareness of potentially low FXIII levels in specific patient populations could help identify patients with acquired FXIII deficiency; although opinions and protocols vary, a cut-off for FXIII activity of ~ 60-70% may be appropriate to diagnose acquired FXIII deficiency and guide supplementation. This narrative review discusses altered FXIII levels in trauma, surgery and wound healing, diagnostic approaches to detect FXIII deficiency and clinical guidance for the treatment of acquired FXIII deficiency.
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Transtornos da Coagulação Sanguínea , Deficiência do Fator XIII , Transtornos da Coagulação Sanguínea/etiologia , Fator XIII/metabolismo , Fator XIII/uso terapêutico , Deficiência do Fator XIII/complicações , Deficiência do Fator XIII/diagnóstico , Deficiência do Fator XIII/tratamento farmacológico , Hemorragia/tratamento farmacológico , Humanos , CicatrizaçãoRESUMO
OBJECTIVES: Sepsis-induced acute kidney injury is the dominant acute kidney injury etiology in critically ill patients and is often associated with a need for renal replacement therapy. The indication and timing of renal replacement therapy are controversially discussed. We hypothesized that the product of the G1-cell cycle arrest biomarkers tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 ([TIMP-2] × [IGFBP7]), and the soluble urokinase-type plasminogen activator receptor are of diagnostic value for the prediction of septic acute kidney injury courses requiring renal replacement therapy. DESIGN: In this prospective study, critically ill patients were enrolled immediately after the fulfillment of Sepsis-3 criteria. Urinary [TIMP-2] × [IGFBP7] levels over time and serum soluble urokinase-type plasminogen activator receptor levels once at inclusion were measured. The primary endpoint was the development of septic acute kidney injury with the need for renal replacement therapy. Area under the receiver operating characteristic curves, de Long's tests, and logistic regression models were calculated. SETTING: Two ICUs at Heidelberg University Hospital between May 2017 and July 2018. PATIENTS: One-hundred critically ill patients with positive Sepsis-3 criteria. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Nineteen patients required renal replacement therapy. Diagnostic performance of urinary [TIMP-2] × [IGFBP7] improved over time with the highest area under the receiver operating characteristic curve of 0.89 (95% CI, 0.80-0.98) 24 hours after study inclusion. Soluble urokinase-type plasminogen activator receptor levels at inclusion showed an area under the receiver operating characteristic curve of 0.83 (0.75-0.92). The best discrimination ability for the primary outcome measure was achieved for [TIMP-2] × [IGFBP7] at 24 hours after inclusion by applying a cutoff value of greater than or equal to 0.6 (ng/mL)/1,000 (sensitivity 90.9, specificity 67.1). Soluble urokinase-type plasminogen activator receptor performed best by using a cutoff value of greater than or equal to 8.53 ng/mL (sensitivity 84.2, specificity 82.7). A combination of newly tested biomarkers with cystatin C resulted in a significantly improved diagnostic accuracy. Cystatin C in combination with [TIMP-2] × [IGFBP7] 24 hours outperformed all standard renal parameters (area under the receiver operating characteristic curve 0.93 [0.86-1.00]). CONCLUSIONS: [TIMP-2] × [IGFBP7] and soluble urokinase-type plasminogen activator receptor are promising biomarker candidates for the risk stratification of septic acute kidney injury patients with the need for renal replacement therapy.
Assuntos
Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/sangue , Receptores de Ativador de Plasminogênio Tipo Uroquinase/sangue , Terapia de Substituição Renal , Sepse/sangue , Sepse/complicações , Injúria Renal Aguda/sangue , Injúria Renal Aguda/diagnóstico , Idoso , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Inibidor Tecidual de Metaloproteinase-2RESUMO
Bacterial RNA serves an important function as activator of the innate immune system. In humans bacterial RNA is sensed by the endosomal receptors TLR7 and TLR8. Differences in the posttranscriptional modification profile of prokaryotic when compared with eukaryotic RNA allow innate immune cells to discriminate between "host" and "foreign" RNA. Ribose 2'-O-methylation is of particular importance and has been reported to antagonize TLR7/8 activation. Yet, the exact sequence context in which 2'-O-methylation has to occur to mediate its inhibitory activity remains largely undefined. On the basis of a naturally occurring 2'-O-methylated RNA sequence, we performed a systematic permutation of the methylated nucleotide as well as adjacent bases and hereby identify two minimal trinucleotide motifs within a 9-mer oligoribonucleotide that are necessary and sufficient to antagonize TLR7 and TLR8 activation, respectively. Given the growing interest in the development of inhibitors of nucleic acid-sensing TLRs for therapeutic purposes, these results will facilitate the rational design of such antagonists in the future.
Assuntos
Motivos de Nucleotídeos , RNA/genética , RNA/metabolismo , Receptor 7 Toll-Like/antagonistas & inibidores , Receptor 8 Toll-Like/antagonistas & inibidores , Citidina , Humanos , Concentração Inibidora 50 , Leucócitos Mononucleares , Metilação , Mutação , Nucleotídeos/química , Nucleotídeos/metabolismo , RNA/química , RNA Bacteriano/química , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA de Transferência/química , RNA de Transferência/genética , RNA de Transferência/metabolismo , Receptor 7 Toll-Like/metabolismo , Receptor 8 Toll-Like/metabolismoRESUMO
BACKGROUND: Postoperative complications are of great relevance in daily clinical practice, and the gut microbiome might play an important role by preventing pathogens from crossing the intestinal barrier. The two aims of this prospective clinical pilot study were: (1) to examine changes in the gut microbiome following pancreatic surgery, and (2) to correlate these changes with the postoperative course of the patient. RESULTS: In total, 116 stool samples of 32 patients undergoing pancreatic surgery were analysed by 16S-rRNA gene next-generation sequencing. One sample per patient was collected preoperatively in order to determine the baseline gut microbiome without exposure to surgical stress and/or antibiotic use. At least two further samples were obtained within the first 10 days following the surgical procedure to observe longitudinal changes in the gut microbiome. Whenever complications occurred, further samples were examined. Based on the structure of the gut microbiome, the samples could be allocated into three different microbial communities (A, B and C). Community B showed an increase in Akkermansia, Enterobacteriaceae and Bacteroidales as well as a decrease in Lachnospiraceae, Prevotella and Bacteroides. Patients showing a microbial composition resembling community B at least once during the observation period were found to have a significantly higher risk for developing postoperative complications (B vs. A, odds ratio = 4.96, p < 0.01**; B vs. C, odds ratio = 2.89, p = 0.019*). CONCLUSIONS: The structure of the gut microbiome is associated with the development of postoperative complications.
Assuntos
Bactérias/classificação , Microbioma Gastrointestinal , Pancreatopatias/cirurgia , Complicações Pós-Operatórias/microbiologia , Idoso , Bactérias/isolamento & purificação , Fezes/microbiologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Razão de Chances , Filogenia , Projetos Piloto , Estudos Prospectivos , RNA Ribossômico 16S/genética , Fatores de RiscoRESUMO
PURPOSE: Despite antifungal prophylaxis following liver transplantation (LTX), patients are at risk for the development of subsequent opportunistic infections, such as an invasive fungal disease (IFD). However, culture-based diagnostic procedures are associated with relevant weaknesses. METHODS: Culture and next-generation sequencing (NGS)-based fungal findings as well as corresponding plasma levels of ß-D-glucan (BDG), galactomannan (GM), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-2, -4, -6, -10, -17A and mid-regional proadrenomedullin (MR-proADM) were evaluated in 93 patients at 6 consecutive time points within 28 days following LTX. RESULTS: A NGS-based diagnostic approach was shown to be suitable for the early identification of fungal pathogens in patients following LTX. Moreover, MR-proADM and IL-17A in plasma proved suitable for the identification of patients with an IFD. CONCLUSION: Plasma measurements of MR-proADM and IL-17A as well as a NGS-based diagnostic approach were shown to be attractive methodologies to attenuate the weaknesses of routinely used culture-based diagnostic procedures for the determination of an IFD in patients following LTX. However, an additional confirmation within a larger multicenter trial needs to be recommended. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00005480 .
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Infecções Fúngicas Invasivas/diagnóstico , Transplante de Fígado , Infecções Oportunistas/diagnóstico , Adulto , Biomarcadores/sangue , DNA Fúngico/sangue , Feminino , Alemanha , Humanos , Unidades de Terapia Intensiva , Infecções Fúngicas Invasivas/microbiologia , Masculino , Pessoa de Meia-Idade , Infecções Oportunistas/microbiologia , Escores de Disfunção Orgânica , Fatores de RiscoRESUMO
A prolonged cold ischaemia time (CIT) is suspected to be associated with an increased ischaemia and reperfusion injury (IRI) resulting in an increased damage to the graft. In total, 91 patients were evaluated for a delayed graft function within 7 days after kidney transplantation (48 deceased, 43 living donors). Blood and urine samples were collected before, immediately after the operation, and 1, 3, 5, 7 and 10 days later. Plasma and/or urine levels of total keratin 18 (total K18), caspase-cleaved keratin 18 (cc K18), the soluble receptor for advanced glycation end products (sRAGE), tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor-binding protein-7 (IGFBP7) were measured. As a result of prolonged CIT and increased IRI, deceased donor transplantations were shown to suffer from a more distinct cell cycle arrest and necrotic cell death. Plasmatic total K18 and urinary TIMP-2 and IGFBP7 were therefore demonstrated to be of value for the detection of a delayed graft function (DGF), as they improved the diagnostic performance of a routinely used clinical scoring system. Plasmatic total K18 and urinary TIMP-2 and IGFBP7 measurements are potentially suitable for early identification of patients at high risk for a DGF following kidney transplantation from deceased or living donors.
Assuntos
Pontos de Checagem do Ciclo Celular , Morte Celular , Isquemia Fria/efeitos adversos , Transplante de Rim/efeitos adversos , Traumatismo por Reperfusão/etiologia , Biomarcadores/sangue , Biomarcadores/urina , Proteína C-Reativa/metabolismo , Função Retardada do Enxerto , Humanos , Queratina-18/sangue , Queratina-18/urina , Pessoa de Meia-Idade , Projetos Piloto , Receptor para Produtos Finais de Glicação Avançada/sangue , Imunologia de TransplantesRESUMO
OBJECTIVES: The impact of TREM-1-mediated inflammation was investigated in different inflammatory settings. METHODS: Secondary analyses of an observational clinical pilot study, including 60 patients with septic shock, 30 postoperative controls and 30 healthy volunteers. RESULTS: Plasma levels of sTREM-1 were found to identify patients with septic shock more effectively than procalcitonin and C-reactive protein. Moreover, sTREM-1 was identified to be an early predictor for survival in patients with septic shock. CONCLUSION: Due to its diagnostic as well as prognostic value in sepsis syndrome, implementation of sTREM-1 measurements in routine diagnostics should be taken into account.
Assuntos
Glicoproteínas de Membrana/sangue , Receptores Imunológicos/sangue , Choque Séptico/sangue , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Humanos , Inflamação/sangue , Pessoa de Meia-Idade , Projetos Piloto , Valor Preditivo dos Testes , Prognóstico , Choque Séptico/diagnóstico , Choque Séptico/mortalidade , Solubilidade , Sobrevida , Receptor Gatilho 1 Expresso em Células MieloidesRESUMO
The aims of the present study were to examine the influence of a low-dose unfractionated heparin regime on platelet aggregation and to additionally assess the prevalence of primary aspirin resistance in patients undergoing carotid endarterectomy. Therefore, 50 patients undergoing carotid endarterectomy were enrolled. A bolus of 3000 IU unfractionated heparin was administered 2 min before carotid cross-clamping additionally to standard antiaggregatory therapy. Haemostaseological point of care testing was performed twice, prior to surgery and 10 min after unfractionated heparin administration by the use of aggregometric and viscoelastic point of care testing. Following unfractionated heparin administration, the activated partial thromboplastin time increased significantly and clotting time in viscoelastic INTEM test was shown to be significantly prolonged. In contrast, the antiaggregatory effect of aspirin was not diminished in aggregometric ASPI test. A low-dose unfractionated heparin regime during carotid endarterectomy was therefore considered to be safe, without diminishing the antiplatelet effect of aspirin. Moreover, aggregometric point of care testing was identified to be a suitable tool for the identification of patients with primary aspirin resistance ( n = 3).
Assuntos
Anticoagulantes/administração & dosagem , Aspirina/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Doenças das Artérias Carótidas/cirurgia , Endarterectomia das Carótidas , Heparina/administração & dosagem , Inibidores da Agregação Plaquetária/uso terapêutico , Agregação Plaquetária/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Aspirina/efeitos adversos , Testes de Coagulação Sanguínea , Doenças das Artérias Carótidas/sangue , Doenças das Artérias Carótidas/diagnóstico por imagem , Resistência a Medicamentos , Endarterectomia das Carótidas/efeitos adversos , Feminino , Heparina/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/efeitos adversos , Testes de Função Plaquetária , Testes Imediatos , Valor Preditivo dos Testes , Estudos Prospectivos , Resultado do TratamentoRESUMO
Ultrathin FeSe films grown on SrTiO3 substrates are a recent milestone in atomic material engineering due to their important role in understanding unconventional superconductivity in Fe-based materials. By using femtosecond time- and angle-resolved photoelectron spectroscopy, we study phonon frequencies in ultrathin FeSe/SrTiO3 films grown by molecular beam epitaxy. After optical excitation, we observe periodic modulations of the photoelectron spectrum as a function of pump-probe delay for 1-unit-cell, 3-unit-cell, and 60-unit-cell thick FeSe films. The frequencies of the coherent intensity oscillations increase from 5.00 ± 0.02 to 5.25 ± 0.02 THz with increasing film thickness. By comparing with previous works, we attribute this mode to the Se A1g phonon. The dominant mechanism for the phonon softening in 1-unit-cell thick FeSe films is a substrate-induced lattice strain. Our results demonstrate an abrupt phonon renormalization due to a lattice mismatch between the ultrathin film and the substrate.
RESUMO
A detailed phenomenology of low energy excitations is a crucial starting point for microscopic understanding of complex materials, such as the cuprate high-temperature superconductors. Because of its unique momentum-space discrimination, angle-resolved photoemission spectroscopy (ARPES) is ideally suited for this task in the cuprates, where emergent phases, particularly superconductivity and the pseudogap, have anisotropic gap structure in momentum space. We present a comprehensive doping- and temperature-dependence ARPES study of spectral gaps in Bi(2)Sr(2)CaCu(2)O(8+δ), covering much of the superconducting portion of the phase diagram. In the ground state, abrupt changes in near-nodal gap phenomenology give spectroscopic evidence for two potential quantum critical points, p = 0.19 for the pseudogap phase and p = 0.076 for another competing phase. Temperature dependence reveals that the pseudogap is not static below T(c) and exists p > 0.19 at higher temperatures. Our data imply a revised phase diagram that reconciles conflicting reports about the endpoint of the pseudogap in the literature, incorporates phase competition between the superconducting gap and pseudogap, and highlights distinct physics at the edge of the superconducting dome.
RESUMO
INTRODUCTION: The role of reactive carbonyl species, such as methylglyoxal (MG), has been overlooked within the context of the sepsis syndrome. The aims of this study were to assess the impact of MG formation in different inflammatory settings and to evaluate its use for early diagnosis as well as prognosis of the sepsis syndrome. METHODS: In total, 120 patients in three groups were enrolled in this observational clinical pilot study. The three groups included patients with septic shock (n = 60), postoperative controls (n = 30), and healthy volunteers (n = 30). Plasma samples from patients with septic shock were collected at sepsis onset and after 24 hours and 4, 7, 14, and 28 days. Plasma samples from postoperative controls were collected prior to surgery, immediately following the end of the surgical procedure as well as 24 hours later and from healthy volunteers once. Plasma levels of MG were determined by high-performance liquid chromatography. Additionally, plasma levels of procalcitonin, C-reactive protein, soluble CD14 subtype, and interleukin-6 were determined. RESULTS: Patients with septic shock showed significantly higher plasma levels of MG at all measured times, compared with postoperative controls. MG was found to identify patients with septic shock more effectively-area under the curve (AUC): 0.993-than procalcitonin (AUC: 0.844), C-reactive protein (AUC: 0.791), soluble CD14 subtype (AUC: 0.832), and interleukin-6 (AUC: 0.898) as assessed by receiver operating characteristic (ROC) analysis. Moreover, plasma levels of MG in non-survivors were significantly higher than in survivors (sepsis onset: *P = 0.018 for 90-day survival; **P = 0.008 for 28-day survival). Plasma levels of MG proved to be an early predictor for survival in patients with septic shock (sepsis onset: ROC-AUC 0.710 for 28-day survival; ROC-AUC 0.686 for 90-day survival). CONCLUSIONS: MG was identified as a marker for monitoring the onset, development, and remission of sepsis and was found to be more useful than routine diagnostic markers. Further studies are required to determine the extent of MG modification in sepsis and whether targeting this pathway could be therapeutically beneficial to the patient. TRIAL REGISTRATION: German Clinical Trials Register DRKS00000505. Registered 8 November 2010.
Assuntos
Aldeído Pirúvico/sangue , Choque Séptico/sangue , Choque Séptico/diagnóstico , Idoso , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos PilotoRESUMO
Trauma-induced coagulopathy (TIC) is a complex hemostatic disturbance that can develop early after a major injury. There is no universally accepted definition of TIC. However, TIC primarily refers to the inability to achieve sufficient hemostasis in severely injured trauma patients, resulting in diffuse microvascular and life-threatening bleeding. Endogenous TIC is driven by the combination of hypovolemic shock and substantial tissue injury, resulting in endothelial damage, glycocalyx shedding, upregulated fibrinolysis, fibrinogen depletion, altered thrombin generation, and platelet dysfunction. Exogenous factors such as hypothermia, acidosis, hypokalemia, and dilution due to crystalloid and colloid fluid administration can further exacerbate TIC. Established TIC upon emergency room admission is a prognostic indicator and is strongly associated with poor outcomes. It has been shown that patients with TIC are prone to higher bleeding tendencies, increased requirements for allogeneic blood transfusion, higher complication rates such as multi-organ failure, and an almost fourfold increase in mortality. Thus, early recognition and individualized treatment of TIC is a cornerstone of initial trauma care. However, patients who survive the initial insult switch from hypocoagulability to hypercoagulability, also termed "late TIC," with a high risk of developing thromboembolic complications.
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Transtornos da Coagulação Sanguínea , Transtornos Plaquetários , Hemostáticos , Ferimentos e Lesões , Humanos , Hemostasia , Hemorragia/etiologia , Fibrinólise , Ferimentos e Lesões/complicaçõesRESUMO
When preparing a movement, we often rely on partial or incomplete information, which can decrement task performance. In behaving monkeys we show that the degree of cued target information is reflected in both, neural variability in motor cortex and behavioral reaction times. We study the underlying mechanisms in a spiking motor-cortical attractor model. By introducing a biologically realistic network topology where excitatory neuron clusters are locally balanced with inhibitory neuron clusters we robustly achieve metastable network activity across a wide range of network parameters. In application to the monkey task, the model performs target-specific action selection and accurately reproduces the task-epoch dependent reduction of trial-to-trial variability in vivo where the degree of reduction directly reflects the amount of processed target information, while spiking irregularity remained constant throughout the task. In the context of incomplete cue information, the increased target selection time of the model can explain increased behavioral reaction times. We conclude that context-dependent neural and behavioral variability is a signum of attractor computation in the motor cortex.