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1.
Open Forum Infect Dis ; 11(6): ofae271, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38868303

RESUMEN

Background: Vascular graft infection (VGI) is a serious complication after implantation of arterial vascular grafts. Optimal surgical and pathogen-specific antimicrobial treatment regimens for VGI are largely unknown. We evaluated patients with arterial VGI according to onset, location, microbiological and imaging characteristics, and surgical and antimicrobial treatment and performed an outcome evaluation. Methods: Consecutive patients with VGI treated in 2 hospitals from 2010 through 2020 were retrospectively analyzed. Uniform definition criteria and standardized outcome evaluation were applied. Logistic regression was used for multiple analysis; survival analysis was performed with Kaplan-Meier analysis and a log-rank test. Results: Seventy-eight patients with VGI were included: 30 early-onset cases (<8 weeks after graft implantation) and 48 late-onset cases, involving 49 aortic and 29 peripheral grafts. The median time from initial implantation to diagnosis of VGI was significantly longer in aortic than peripheral VGIs (363 vs 56 days, P = .018). Late-onset VGI (odds ratio [OR], 7.3; P = .005) and the presence of surgical site infection/complication (OR, 8.21; P = .006) were independent risk factors for treatment failure. Surgical site infection/complication was associated with a higher risk for early-onset VGI (OR, 3.13; P = .040). Longer infection-free survival was observed in cases where the infected graft was surgically removed (P = .037). Conclusions: This study underlines the importance of timely diagnosis of VGI and preventing surgical site infections/complications at graft implantation. It highlights the complexity of infection eradication, especially for late-onset infections, and the importance of adequate antimicrobial and surgical treatment.

2.
Adv Mater ; : e2407712, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38940342

RESUMEN

Developing strong and simultaneously tough polymeric materials with excellent thermal stability and mechanical performance even under extreme temperatures is truly a challenge. In a disruptive progress, continuous polymeric yarns are developed with a combination of high tensile strength of (1145 ± 44) MPa and ultrahigh toughness of (350 ± 24) J g-1 and high thermomechanical properties from -196 to 200 °C. The comprehensive thermomechanical performance of this yarn surpasses that of previously developed polymeric materials and dragline spider silks. The results demonstrate that the molecular structure of polyimide (PI) with the incorporation of flexible-rigid macromolecular, hierarchically spiral-oriented fibers, and high glass transition temperature (248 °C) are keys for the yarn's notable comprehensive performance in thermomechanical properties. The materials are ideal for technical components exposed to high thermomechanical loadings, such as those encountered in spacecraft or automotive engineering for safety-critical applications.

3.
Hamostaseologie ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38925155

RESUMEN

May-Thurner syndrome (MTS) is a pelvic venous disorder involving compression of the left common iliac vein by the right common iliac artery, which results in predisposition for deep vein thrombosis. Although MTS is increasingly recognized in young patients, specific guidelines on diagnosis and management for children, adolescents, and young adults do not exist so far. The aim of this study was to assess current diagnostic and therapeutic practice in Germany, Austria, and Switzerland in children and young adults with thrombosis and MTS.We designed an online survey with 11 questions, which we sent via a mailing list to all members of the German, Austrian, and Swiss Society of Thrombosis and Haemostasis Research. Between July and October 2022, 33 specialists answered the questionnaire. Most participating specialists worked at pediatric hospitals (61%). Numbers of annually treated thromboses ranged from <5 (26%) to >30 (13%). Most specialists used venous ultrasound to diagnose deep vein thrombosis, 53% magnetic resonance imaging. Only 25% of specialists systematically screened for MTS in deep vein thrombosis. MTS was managed with anticoagulation (65%), iliac vein stent placement (32%), or balloon angioplasty (13%). In total, 31% of specialists reported to use more than one therapeutic method. Diagnostic and therapeutic approaches for MTS differed between specialists. Lack of standardization resulted in individualized and highly diverse management. Prospective observational clinical studies investigating the outcome of different management strategies including long-term follow-up on outcome and incidence of postthrombotic syndrome will help in defining patient groups who benefit most from revascularizing interventional strategies and developing standardized guidelines.

4.
Sci Rep ; 14(1): 12795, 2024 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-38834580

RESUMEN

Cytokine-mediated systemic inflammation after open thoracoabdominal aortic aneurysm (TAAA) repairs plays a pivotal role in disrupting circulatory homeostasis, potentially leading to organ dysfunction. The bioactive form of adrenomedullin (bio-ADM) is a peptide hormone with immunomodulatory and vasomotor effects, making it a potential diagnostic agent in these cases. This retrospective, bicentric study, conducted between January 2019 and December 2022, recruited 36 elective open TAAA repair patients in two German centres. Serum and plasma samples were collected at multiple time points to measure bio-ADM levels. The primary objective was to evaluate the association of bio-ADM levels with the onset of acute respiratory distress syndrome (ARDS), with secondary endpoints focusing on mortality and SIRS-related morbidity. Results showed a significant association between postoperative bio-ADM levels (12-48 h after surgery) and the onset of ARDS (p < .001), prolonged ventilation (p = .015 at 12h after surgery), atrial fibrillation (p < .001), and mortality (p = .05 at 24h). The biomarker was also strongly associated with sepsis (p = .01 at 12 h) and multi-organ dysfunction syndrome (MODS) (p = .02 at 24 h after surgery). The study underscores the potential utility of bio-ADM as a diagnostic tool for identifying patients at risk of postoperative complications following open TAAA repairs.


Asunto(s)
Adrenomedulina , Aneurisma de la Aorta Torácica , Biomarcadores , Complicaciones Posoperatorias , Síndrome de Dificultad Respiratoria , Humanos , Adrenomedulina/sangre , Masculino , Femenino , Síndrome de Dificultad Respiratoria/etiología , Síndrome de Dificultad Respiratoria/sangre , Persona de Mediana Edad , Anciano , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/sangre , Estudios Retrospectivos , Aneurisma de la Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/sangre , Biomarcadores/sangre , Sepsis/sangre , Sepsis/etiología , Insuficiencia Multiorgánica/etiología , Insuficiencia Multiorgánica/sangre , Insuficiencia Multiorgánica/mortalidad , Insuficiencia Multiorgánica/diagnóstico , Periodo Posoperatorio
5.
J Endovasc Ther ; : 15266028241255533, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38804508

RESUMEN

PURPOSE: In some cases of endovascular thoracoabdominal or juxtarenal aortic aneurysm repair, a thoracic endograft in combination with a fenestrated renovisceral device may be needed in order to create a sufficient proximal landing zone. This study aimed to evaluate the technical aspects and postoperative morbidity of a single- or 2-stage approach. METHODS: Eighty-seven consecutive patients undergoing thoracic endovascular aortic repair (TEVAR) in combination with elective fenestrated repair (fenestrated endovascular aortic repair [FEVAR]; fenestrated Anaconda device) from 2015 to 2022 were included in this retrospective bicentric study. Underlying pathologies, aortic morphology, technical details, and postoperative morbidity were recorded. RESULTS: Single-staged ("1S," n=61) and 2-staged ("2S," n=26) interventions were compared. Indications were thoracoabdominal aneurysms (TAAAs) (Crawford I-IV) (n=56, 64%) and juxtarenal aneurysms (n=31, 36%). In 2S, the proportion of TAAA was higher than in 1S (2S: 77%, 1S: 59%; p=0.001). In 2S, the covered length of the descending aorta was longer (1S: 128±60 mm, 2S: 202±64 mm; p=0.003). Temporary aneurysm sack perfusion (TASP) was established in 11 (18%) of 1S and 1 (4%) of 2S patients (p=0.079), as well as cerebrospinal fluid (CSF) drainage catheter in 48 (79%) of 1S and 19 (73%) of 2S. The rate of spinal cord ischemia (SCI) and the severity of SCI were not different in both groups, with a total of 3 cases of persisting paraplegia. The rate of access complications was higher in 2S (n=6, 23%) than in 1S (n=4, 7%; p=0.027). Postoperative 30 day morbidity did not significantly differ in both groups and neither did 30 day mortality (4.6% in 1S vs 3.8% in 2S; p=0.083). CONCLUSION: The combination of TEVAR and FEVAR using a fenestrated endograft is feasible and safe. Aortic morphology does not change significantly after endovascular repair. A single-staged strategy is feasible with excellent results, especially in Crawford IV, Crawford V, or juxtarenal aneurysms. Two-staged repair is recommended in cases with long aortic coverage and a higher American Society of Anesthesiologists (ASA) class. Follow-up data are needed to evaluate the long-term stability of the TEVAR/FEVAR interconnection. CLINICAL IMPACT: Our study has revealed the safety and efficacy of the combination of TEVAR and FEVAR in the treatment of TAAAs and juxtarenal aneurysms with compromised supravisceral landing zones. A single-staged concept is not necessary in all cases. Staged procedures may reduce postoperative morbidity in cases with long aortic coverage and higher ASA class.

6.
J Cell Mol Med ; 28(8): e18126, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38534092

RESUMEN

Peripheral arterial disease (PAD) is an increasing cause of morbidity and its severity is graded based on clinical manifestation. To investigate the influence of the different stages on myopathy of ischemic muscle we analysed severity-dependent effects of mitochondrial respiration in PAD. Eighteen patients with severe PAD, defined as chronic limb-threatening ischemia, 47 patients with intermittent claudication (IC) and 22 non-ischemic controls were analysed. High-resolution respirometry (HRR) was performed on muscle biopsies of gastrocnemius and vastus lateralis muscle of patients in different PAD stages to investigate different respiratory states. Results from HRR are given as median and interquartile range and were normalized to citrate synthase activity (CSA), a marker for mitochondrial content. In order to account for inter-individual differences between patients and controls, we calculated the ratio of O2-flux in gastrocnemius muscle over vastus muscle ('GV ratio'). CSA of the gastrocnemius muscle as a proxy for mitochondrial content was significantly lower in critical ischemia compared to controls. Mitochondrial respiration normalized to CSA was higher in IC compared to controls. Likewise, the GV ratio was significantly higher in IC compared to control. Mitochondrial respiration and CSA of PAD patients showed stage-dependent modifications with greater changes in the mild PAD stage group (IC).


Asunto(s)
Mitocondrias , Enfermedad Arterial Periférica , Humanos , Músculo Esquelético/metabolismo , Claudicación Intermitente/metabolismo , Claudicación Intermitente/patología , Respiración
7.
J Cardiothorac Vasc Anesth ; 38(5): 1092-1102, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38310068

RESUMEN

A thoracoabdominal aortic aneurysm (TAAA) can be potentially life-threatening due to its associated risk of rupture. Thoracoabdominal aortic aneurysm repair, performed as endovascular repair and/or open surgery, is the recommended therapy of choice. Hemodynamic instability, severe blood loss, and spinal cord or cerebral ischemia are some potential hazards the perioperative team has to face during these procedures. Therefore, preoperative risk assessment and intraoperative anesthesia management addressing these potential hazards are essential to improving patients' outcomes. Based on a presented index case, an overview focusing on anesthetic measures to identify perioperatively and manage these risks in TAAA repair is provided.


Asunto(s)
Aneurisma de la Aorta Torácica , Aneurisma de la Aorta Toracoabdominal , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Humanos , Aneurisma de la Aorta Torácica/cirugía , Implantación de Prótesis Vascular/métodos , Anestesiólogos , Resultado del Tratamiento , Estudios Retrospectivos , Procedimientos Endovasculares/métodos , Factores de Riesgo , Complicaciones Posoperatorias/cirugía
8.
Sci Rep ; 14(1): 2282, 2024 01 27.
Artículo en Inglés | MEDLINE | ID: mdl-38280916

RESUMEN

Research on the plastic contamination of organic fertilizer (compost) has largely concentrated on particles and fragments > 1 mm. Small, submillimeter microplastic particles may be more hazardous to the environment. However, research on their presence in composts has been impeded by the difficulty to univocally identify small plastic particles in such complex matrices. Here a method is proposed for the analysis of particles between 0.01 and 1.0 mm according to number, size, and polymer type in compost. As a first demonstration of its potential, the method is used to determine large and small microplastic in composts from eight municipal compost producing plants: three simple biowaste composters, four plants processing greenery and cuttings and one two-stage biowaste digester-composter. While polyethylene, PE, tends to dominate among fragments > 1 mm, the microplastic fraction contained more polypropylene, PP. Whereas the contamination with PE/PP microplastic was similar over the investigated composts, only composts prepared from biowaste contained microplastic with a signature of biodegradable plastic, namely poly(butylene adipate co-terephthalate), PBAT. Moreover, in these composts PBAT microplastic tended to form the largest fraction. When the bulk of residual PBAT in the composts was analyzed by chloroform extraction, an inverse correlation between the number of particles > 0.01 mm and the total extracted amount was seen, arguing for breakdown into smaller particles, but not necessarily a mass reduction. PBAT oligomers and monomers as possible substrates for subsequent biodegradation were not found. Remaining microplastic will enter the environment with the composts, where its subsequent degradability depends on the local conditions and is to date largely uninvestigated.


Asunto(s)
Compostaje , Plásticos , Plásticos/análisis , Microplásticos , Polímeros , Polipropilenos
9.
J Mol Biol ; 436(5): 168257, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37657609

RESUMEN

Sensory photoreceptors abound in nature and enable organisms to adapt behavior, development, and physiology to environmental light. In optogenetics, photoreceptors allow spatiotemporally precise, reversible, and non-invasive control by light of cellular processes. Notwithstanding the development of numerous optogenetic circuits, an unmet demand exists for efficient systems sensitive to red light, given its superior penetration of biological tissue. Bacteriophytochrome photoreceptors sense the ratio of red and far-red light to regulate the activity of enzymatic effector modules. The recombination of bacteriophytochrome photosensor modules with cyclase effectors underlies photoactivated adenylyl cyclases (PAC) that catalyze the synthesis of the ubiquitous second messenger 3', 5'-cyclic adenosine monophosphate (cAMP). Via homologous exchanges of the photosensor unit, we devised novel PACs, with the variant DmPAC exhibiting 40-fold activation of cyclase activity under red light, thus surpassing previous red-light-responsive PACs. Modifications of the PHY tongue modulated the responses to red and far-red light. Exchanges of the cyclase effector offer an avenue to further enhancing PACs but require optimization of the linker to the photosensor. DmPAC and a derivative for 3', 5'-cyclic guanosine monophosphate allow the manipulation of cyclic-nucleotide-dependent processes in mammalian cells by red light. Taken together, we advance the optogenetic control of second-messenger signaling and provide insight into the signaling and design of bacteriophytochrome receptors.


Asunto(s)
Adenilil Ciclasas , AMP Cíclico , Deinococcus , Fotorreceptores Microbianos , Fitocromo , Proteínas Recombinantes de Fusión , Animales , Adenilil Ciclasas/química , Adenilil Ciclasas/genética , AMP Cíclico/química , Luz , Optogenética , Transducción de Señal , Ingeniería de Proteínas , Fitocromo/química , Fitocromo/genética , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Fotorreceptores Microbianos/química , Fotorreceptores Microbianos/genética
10.
Vasa ; 53(1): 61-67, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37965700

RESUMEN

Background: Acute kidney injury (AKI) after open thoracoabdominal aortic aneurysm repairs (TAAA) is a common postoperative complication, associated with increased mortality and morbidity. Early detection and management of the kidney tissue damage remains of paramount importance. The aim of this prospectively conducted, observational trial was to evaluate the clinical applicability of Proenkephalin A 119-159 (penKid) for the detection of postoperative AKI. Patients and methods: Thirty-six patients, planned for elective open TAAA repairs from January 2019 to December 2022, were recruited in two German centres (University Hospital Aachen and Charité - University Hospital Berlin). Blood samples were collected pre-surgery (baseline), directly postoperatively and at 12, 24 and 48 hours after surgery. The penKid concentration in plasma was measured using the immunoluminometric sphingotest® assay kit and they were statistically tested for association with AKI and other clinical parameters. Results: Twenty-four patients (62%) developed moderate or severe AKI postoperatively (Stage 2 or 3 of the KDIGO classification) and they had a significantly increased risk for the development of acute respiratory distress syndrome (p=.023) or a fatal outcome (p=.035). Starting from the 12th hour after surgery, we found penKid correlating with AKI stage 2/3 (12 hour penKid mean in pmol/L: 93.9 vs. 43.1; c index .776, p=.0037) and renal replacement therapy (12 hour c index .779, p=.0035). Patients with multi-organ dysfunction syndrome had significantly increased penKid levels at all timepoints. Conclusions: We found penKid to be a promising biomarker for the early detection of postoperative AKI and in-hospital mortality after open TAAA repair, which may enable the early initiation of organ-protective strategies and reduction of further complications associated with AKI.


Asunto(s)
Lesión Renal Aguda , Aneurisma de la Aorta Torácica , Humanos , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/etiología , Aorta , Biomarcadores , Estudios Retrospectivos , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , Resultado del Tratamiento , Factores de Riesgo , Aneurisma de la Aorta Torácica/cirugía
11.
Adv Sci (Weinh) ; 11(9): e2304098, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38145363

RESUMEN

Semiochemicals such as pheromones play a major role in communication between insects, influencing their spatial orientation, aggregation, defense, and mating. The rational chemical design of precision pheromone-releasing materials are increased the efficiency of pheromone-based plant protection agents. Decades of research is begun to unravel the complex communication structures regulated by semiochemicals, from the neuronal perception of specific chemical substances to the behavioral responses in hundreds of species, including many devastating pest insects. This article summarizes the most effective uses of semiochemicals in agriculture, the behavioral responses of selected target species, and controlled-release strategies based on formulations such as novel fibrous polymer carriers. This study helps scientists, decision-makers, farmers, and the public understand the importance of appropriate mating disruption techniques that reduce the need for broad-spectrum insecticides and limit their impact on non-target and beneficial insects.


Asunto(s)
Control de Insectos , Feromonas , Animales , Feromonas/farmacología , Feromonas/fisiología , Control de Insectos/métodos , Insectos
12.
J Surg Case Rep ; 2023(12): rjad671, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38111497

RESUMEN

Ischemic hepatitis due to mesenteric artery occlusion is extremely rare. This is due to the function of the collateral network of the celiac-mesenteric arterial system and portal venous flow. A 64-year-old male presented with abdominal pain, a significantly reduced general condition, a weight loss of 20 kg in 4 months. Computed tomography showed occlusion of the celiac trunk and the superior mesenteric artery and hypodense lesions in the liver. We performed an antegrade visceral reconstruction with a bifurcated 12-6 mm Dacron graft from the supra-celiac aortic donor to the superior mesenteric and celiac arteries. The postoperative course and follow-up were uneventful.

13.
Artículo en Inglés | MEDLINE | ID: mdl-37796303

RESUMEN

Active locomotion plays an important role in the life of many animals, permitting them to explore the environment, find vital resources, and escape predators. Most insect species rely on a combination of visual cues such as celestial bodies, landmarks, or linearly polarized light to navigate or orient themselves in their surroundings. In nature, linearly polarized light can arise either from atmospheric scattering or from reflections off shiny non-metallic surfaces like water. Multiple reports have described different behavioral responses of various insects to such shiny surfaces. Our goal was to test whether free-flying Drosophila melanogaster, a molecular genetic model organism and behavioral generalist, also manifests specific behavioral responses when confronted with such polarized reflections. Fruit flies were placed in a custom-built arena with controlled environmental parameters (temperature, humidity, and light intensity). Flight detections and landings were quantified for three different stimuli: a diffusely reflecting matt plate, a small patch of shiny acetate film, and real water. We compared hydrated and dehydrated fly populations, since the state of hydration may change the motivation of flies to seek or avoid water. Our analysis reveals for the first time that flying fruit flies indeed use vision to avoid flying over shiny surfaces.


Asunto(s)
Drosophila melanogaster , Drosophila , Animales , Drosophila melanogaster/fisiología , Drosophila/fisiología , Visión Ocular , Luz , Insectos , Agua , Vuelo Animal/fisiología
14.
Sci Rep ; 13(1): 11096, 2023 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-37423933

RESUMEN

Acute kidney injury (AKI) is a common complication after complex aortic procedures and it is associated with relevant mortality and morbidity. Biomarkers for early and specific AKI detection are lacking. The aim of this work is to investigate the reliability of the NephroCheck bedside system for diagnosing stage 3 AKI following open aortic surgery. In this prospective, multicenter, observational study,- https://clinicaltrials.gov/ct2/show/NCT04087161 -we included 45 patients undergoing open thoracoabdominal aortic repair. AKI risk (AKIRisk-Index) was calculated from urine samples at 5 timepoints: baseline, immediately postoperatively and at 12, 24, 48, and 72 h post-surgery. AKIs were classified according to the KDIGO criteria. Contributing factors were identified in univariable and multivariable logistic regression. Predictive ability was assessed with the area under the receiver operator curve (ROCAUC). Among 31 patients (68.8%) that developed AKIs, 21 (44.9%) developed stage-3 AKIs, which required dialysis. AKIs were correlated with increased in-hospital mortality (p = .006), respiratory complications (p < .001), sepsis (p < .001), and multi-organ dysfunction syndrome (p < .001). The AKIRisk-Index showed reliable diagnostic accuracy starting at 24 h post-surgery (ROCAUC: .8056, p = .001). In conclusion, starting at 24 h after open aortic repair, the NephroCheck system showed adequate diagnostic accuracy for detecting the patients at risk for stage 3 AKIs.


Asunto(s)
Lesión Renal Aguda , Diálisis Renal , Humanos , Estudios Prospectivos , Reproducibilidad de los Resultados , Diálisis Renal/efectos adversos , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/etiología , Biomarcadores/orina
15.
J Clin Med ; 12(12)2023 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-37373851

RESUMEN

(1) Background: This retrospective study evaluated perioperative and intensive care unit (ICU) variables to predict colonic ischemia (CI) after infrarenal ruptured abdominal aortic aneurysm (RAAA) surgery. (2) Materials and Methods: We retrospectively analyzed the data of the patients treated for infrarenal RAAA from January 2011 to December 2020 in our hospital. (3) Results: A total of 135 (82% male) patients were admitted to ICU after treatment of infrarenal RAAA. The median age of all patients was 75 years (IQR 68-81 years). Of those, 24 (18%) patients developed CI, including 22 (92%) cases within the first three postoperative days. CI was found more often after open repair compared to endovascular treatment (22% vs. 5%, p = 0.021). Laboratory findings in the first seven PODs revealed statistically significant differences between CI and non-CI patients for serum lactate, minimum pH, serum bicarbonate, and platelet count. Norepinephrine (NE) was used in 92 (68%) patients during ICU stay. The highest daily dose of norepinephrine was administered to CI patients at POD1. Multivariable analysis revealed that NE > 64 µg/kg (RD 0.40, 95% CI: 0.25-0.55, p < 0.001), operating time ≥ 200 min (RD 0.18, 95% CI: 0.05-0.31, p = 0.042), and pH < 7.3 (RD 0.21, 95% CI: 0.07-0.35, p = 0.019), significantly predicted the development of CI. A total of 23 (17%) patients died during the hospital stay, including 8 (33%) patients from the CI group and 15 (7%) from the non-CI group (p = 0.032). (4) Conclusions: CI after RAAA is a sever complication occurring most frequently within the first 3 postoperative days. Our study identified many surrogate markers associated with colonic ischemia after aortic RAAA, including norepinephrine dose > 64 µg/kg, operating time ≥ 200 min, and PH < 7.3. Future studies are needed to support these results.

16.
Environ Sci Technol ; 57(27): 9925-9933, 2023 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-37364870

RESUMEN

Polystyrene (PS) is an important model polymer for the investigation of effects of microplastic (MP) and nanoplastic (NP) particles on living systems. Aqueous dispersions of PS MP or NP contain residual monomers of styrene. In consequence, it is not clear if the effects observed in standard (cyto)toxicity studies are evoked by the polymer (MP/NP) particle or by residual monomers. We addressed that question by comparing standard PS model particle dispersions with in-house synthesized PS particle dispersions. We proposed a rapid purification method of PS particle dispersions by dialysis against mixed solvents and developed a simple method of UV-vis spectrometry to detect residual styrene in the dispersions. We found that standard PS model particle dispersions, which contain residual monomers, exerted a low but significant cytotoxicity on mammalian cells, while the in-house synthesized PS, after rigorous purification to reduce the styrene content, did not. However, the PS particles per se but not the residual styrene in both PS particle dispersions resulted in immobilization of Daphnia. Only by using freshly monomer-depleted particles, will it be possible in the future to assess the (cyto)toxicities of PS particles, avoiding an otherwise not controllable bias effect of the monomer.


Asunto(s)
Microplásticos , Poliestirenos , Animales , Poliestirenos/toxicidad , Microplásticos/toxicidad , Plásticos , Polímeros , Solventes , Mamíferos
17.
Macromol Biosci ; 23(11): e2300143, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37357761

RESUMEN

Biodegradable electrospun sponges are of interest for various applications including tissue engineering, drug release, dental therapy, plant protection, and plant fertilization. Biodegradable electrospun poly(l-lactide)/poly(ε-caprolactone) (PLLA/PCL) blend fiber-based sponge with hierarchical pore structure is inherently hydrophobic, which is disadvantageous for application in tissue engineering, fertilization, and drug delivery. Contact angles and model studies for staining with a hydrophilic dye for untreated, plasma-treated, and surfactant-treated PLLA/PCL sponges are reported. Thorough hydrophilization of PLLA/PCL sponges is found only with surfactant-treated sponges. The MTT assay on the leachates from the sponges does not indicate any cell incompatibility. Furthermore, the cell proliferation and penetration of the hydrophilized sponges are verified by in vitro cell culture studies using MG63 and human fibroblast cells.


Asunto(s)
Poliésteres , Ingeniería de Tejidos , Humanos , Poliésteres/farmacología , Poliésteres/química , Tensoactivos , Andamios del Tejido/química
18.
Macromol Rapid Commun ; 44(19): e2300256, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37220654

RESUMEN

This work reports on the synthesis of statistical copolymers of bio-based PA 6.19 and PA 6.6 together with the production of melt-spun monofilaments for the production of sustainable textile fibers. The plant oil-based 1.19-nonadecanedioic acid is synthesized from bio-derived oleic acid via isomerizing methoxycarbonylation. The homopolymer PA 6.19 with a carbon-based bio-content of 72% shows a good elongation at break of 166%, but lower tensile strength than commercial PA 6 (43 MPa versus 82 MPa). Addition of adipic acid to form statistical PA 6.6/6.19 copolymers improves toughness while maintaining the high elongation at break. Two PA 6.6/6.19 copolymers with a carbon-based bio-content of 26% and 33% are successfully synthesized and exhibited comparable toughness (94  ±  6 MPa and 92  ±  2 MPa) to the commercial PA 6 (92  ±  15 MPa). The bio-based copolymers also exhibit a much lower water uptake than PA 6 and PA 6.6, resulting in a higher dimensional stability. Melt spinning of the oleic acid-based polyamides is successfully carried out to produce monofilaments with sufficient properties for further processing in a knitting process, demonstrating the capabilities of the bio-based PA 6.6/6.19 copolymers for use in the textile industry.


Asunto(s)
Ácido Oléico , Polímeros , Resistencia a la Tracción , Nylons , Carbono
19.
Sci Adv ; 9(13): eade6066, 2023 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-37000874

RESUMEN

Materials with an extremely low thermal and high electrical conductivity that are easy to process, foldable, and nonflammable are required for sustainable applications, notably in energy converters, miniaturized electronics, and high-temperature fuel cells. Given the inherent correlation between high thermal and high electrical conductivity, innovative design concepts that decouple phonon and electron transport are necessary. We achieved this unique combination of thermal conductivity 19.8 ± 7.8 mW/m/K (cross-plane) and 31.8 ± 11.8 mW/m/K (in-plane); electrical conductivity 4.2 S/cm in-plane in electrospun nonwovens comprising carbon as the matrix and silicon-based ceramics as nano-sized inclusions with a sea-island nanostructure. The carbon phase modulates electronic transport for high electrical conductivity, and the ceramic phase induces phonon scattering for low thermal conductivity by excessive boundary scattering. Our strategy can be used to fabricate the unique nonwoven materials for real-world applications and will inspire the design of materials made from carbon and ceramic.

20.
Vascular ; 31(5): 850-857, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35549485

RESUMEN

OBJECTIVE: To report and compare neoaortoiliac system reconstruction and cryopreserved human allograft in treating aortic graft infections. METHODS: We retrospectively analysed the data of the patients treated for aorto graft infections between January 2015 and May 2021 in our hospital. The clinical data, diagnostic procedures, and surgical options were evaluated. The primary endpoint of this study was the 30-day and 1-year mortality; secondary endpoints were major postoperative complications. RESULTS: We retrospectively reviewed a series of 31 consecutive patients (28 males; median age 72 years, range, 50-87 years) with aortic graft infection treated with NAIS (n = 20, 65%) or cryopreserved allograft (n = 11, 36%). The clinical presentation included fever attacks in 18 (58%) patients, abdominal pain in 15 (48%) patients, haemodynamic instability in 6 (19%) patients, and haematemesis in 2 (7%) patients. The median operative time of the NAIS was longer than CHA without a statistically significant difference (458 min vs. 359 min, p = .505). The postoperative morbidity for all patients was 81%, with no significant difference between NAIS and CHA groups (85% vs. 73%, p = .638). There was no limb thrombosis of the new reconstructions. Limb loss occurred in 4 (13%) patients, including 2 (10%) NAIS patients and 2 (18%) CHA patients. One NAIS patient developed complications in the form of a distal (femoral) disruption of the vein 15 days after surgery. There were no significant differences between NAIS and CHA groups in ICU stay (12 vs 8 days, .984) but in hospitalization (22 vs 33, p = .033). The most common bacteria isolated were staphylococci strains in 15 (48%). In 13 (36%) patients, candida was positive. The in-hospital 30-day and 1-year mortality for all patients was 16% (5/31) and 29% (9/31), with no significant differences between NAIS and CHA at 30 days (25% vs. 0, p = .133) or 1 year (35% vs. 18%, .429). Five NAIS patients died during the hospital stay; three of them had end-of-life decisions. After a median follow-up of 16 months (1-66 months), 12 (39%) patients died, including 9 patients with NAIS and 3 with CHA reconstructions. The causes of death included overwhelming sepsis in 5 (42%) patients, graft disruption in one (8%) NAIS patient, non-small cell lung cancer in one (8%) patient, COVID-19 in one (8%) patient and unknown causes (8%) in one. CONCLUSIONS: Non-staged neoaortoiliac system reconstruction and cryopreserved human allografts show comparable short- and midterm results for treating aortic graft infections. However, both procedures remain challenging with high morbidity and mortality rates.


Asunto(s)
Implantación de Prótesis Vascular , COVID-19 , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Infecciones Relacionadas con Prótesis , Masculino , Humanos , Anciano , Prótesis Vascular/efectos adversos , Estudios Retrospectivos , Carcinoma de Pulmón de Células no Pequeñas/etiología , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Infecciones Relacionadas con Prótesis/diagnóstico , Infecciones Relacionadas con Prótesis/cirugía , Infecciones Relacionadas con Prótesis/microbiología , Resultado del Tratamiento , Neoplasias Pulmonares/etiología , Neoplasias Pulmonares/cirugía , Implantación de Prótesis Vascular/efectos adversos , Aloinjertos/cirugía , Factores de Riesgo
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