Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 67
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Analyst ; 147(7): 1294-1312, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35275148

RESUMO

The development of high-resolution molecular printing allows the engineering of analytical platforms enabling applications at the interface between chemistry and biology, i.e. in biosensing, electronics, single-cell biology, and point-of-care diagnostics. Their successful implementation stems from the combination of large area printing at resolutions from sub-100 nm up to macroscale, whilst controlling the composition and volume of the ink, and reconfiguring the deposition features in due course. Similar to handwriting pens, the engineering of continuous writing systems tackles the issue of the tedious ink replenishment between different printing steps. To this aim, this review article provides an unprecedented analysis of the latest continuous printing methods for bioanalytical chemistry, focusing on ink deposition systems based on specific sets of technologies that have been developed to this aim, namely nanofountain probes, microcantilever spotting, capillary-based polymer pens and continuous 3D printing. Each approach will be discussed revealing the most important applications in the fields of biosensors, lab-on-chips and diagnostics.


Assuntos
Técnicas Biossensoriais , Impressão Tridimensional , Dispositivos Lab-On-A-Chip , Polímeros , Redação
2.
Ann Vasc Surg ; 86: 219-228, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35461993

RESUMO

BACKGROUND: The invasion of truncal arteries and veins by malignant neoplasms is rare and the surgical treatment remains a challenge. Several techniques can be used to re-establish blood flow in a resected vessel and choice of the ideal vascular substitute frequently arises a debate. Comparative studies between prosthetic and autologous grafts disclose conflicting patency results. The aim of this study is to compare patency outcomes of vascular reconstructions performed using autologous or prosthetic replacement grafts in surgical oncology, in light of a standardized antithrombotic protocol used in our institution since 1997. METHODS: This retrospective study compared patency of prosthetic versus autologous interposition grafts following the resection of malignancies in 117 patients between September 1997 and February 2020. The 181 reconstruction procedures performed were analyzed according to the body segment involved, and divided into: head and neck, thorax, abdomen, and extremities. RESULTS: Overall survival estimates after 24 and 60 months were 53.2% (standard error 4.8%) and 38.1% (standard error 4.9%), respectively. No significant difference was observed between overall arterial patency, using autologous or synthetic grafts (P = 0.41). Overall venous patency showed a tendency to be lower in synthetic grafts, although no significant difference was observed (P = 0.062). For both arterial and venous reconstructions in the extremities (upper and lower limbs), significantly higher patency was observed using autologous grafts. CONCLUSIONS: Autologous long-term graft patency may be superior to prosthetic in vascular reconstructions associated with malignancies of the extremities. This outcome was obtained using a standardized post-operative anticoagulation protocol.


Assuntos
Implante de Prótese Vascular , Neoplasias , Humanos , Grau de Desobstrução Vascular , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/métodos , Estudos Retrospectivos , Resultado do Tratamento , Neoplasias/diagnóstico , Anticoagulantes/efeitos adversos
3.
Langmuir ; 37(34): 10354-10365, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34461725

RESUMO

Fine control of nanoparticle clustering within polymeric matrices can be tuned to enhance the physicochemical properties of the resulting composites, which are governed by the interplay of nanoparticle surface segregation and bulk clustering. To this aim, out-of-equilibrium strategies can be leveraged to program the multiscale organization of such systems. Here, we present experimental results indicating that bulk assembly of highly photoactive clusters of titanium dioxide nanoparticles within an in situ synthesized polysiloxane matrix can be thermally tuned. Remarkably, the controlled nanoparticle clustering results in improved degradation photocatalytic performances of the material under 1 sun toward methylene blue. The resulting coatings, in particular the 35 wt % TiO2-loaded composites, show a photocatalytic degradation of about 80%, which was comparable to the equivalent amount of bare TiO2 and two-fold higher with respect to the corresponding composites not subjected to thermal treatment. These findings highlight the role of thermally induced bulk clustering in enhancing photoactive nanoparticle/polymer composite properties.

4.
Ann Vasc Surg ; 71: 220-229, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32891742

RESUMO

BACKGROUND: Standard treatment for venous thromboembolism is anticoagulation; vena cava filter placement is an alternative in special situations. We aimed to evaluate the outcomes in patients with cancer undergoing filter placement in a cancer center during a 10-year period and assess which preoperatory variables were associated with poorer survival. METHODS: Retrospective unicenter analysis during a 10-year period was carried out in patients with cancer who had undergone placement of vena cava filter. Early deaths were those that occurred less than 30 days after the filter placement or that occurred during the same hospital stay of the placement. RESULTS: About 250 patients were analyzed. About 51.6% were females; 77.2% had proximal lower limb deep vein thrombosis; 34.8% had contraindications to anticoagulation; 32.8% presented bleeding after the onset of anticoagulation; and 18.4% had the filter implanted because they were going to undergo surgery and could not be anticoagulated immediately after. About 51.2% of the filters were removable. However, only 2 had the filter removed. About 59.2% had metastatic disease at the time of filter placement. About 31.2% fulfilled criteria for early death. Of those, 34 patients were put in palliative care after filter insertion (median, 13.5 days). Body mass index >18 kg/m2, the absence of metastatic disease, and filter placement during the same anesthesia of another surgery (especially if elective and curative) were associated with a higher chance of survival. CONCLUSIONS: Multidisciplinary evaluation (and possibly consideration for palliation) should take place before the decision to insert a vena cava filter in severe oncologic cases depending on overall status. Patients with a greater chance of survival at a 3 or 5 years interval seem to be those whose filters were placed in the perioperative context of other surgeries (specially elective and curative), who were not undernourished, and whose disease was not metastatic at that time. For patients who survived, an active investigation protocol for filter removal should be implemented.


Assuntos
Neoplasias/terapia , Implantação de Prótese/instrumentação , Filtros de Veia Cava , Tromboembolia Venosa/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Tomada de Decisão Clínica , Contraindicações de Medicamentos , Remoção de Dispositivo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Neoplasias/diagnóstico , Neoplasias/mortalidade , Seleção de Pacientes , Implantação de Prótese/efeitos adversos , Implantação de Prótese/mortalidade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/mortalidade , Adulto Jovem
5.
Small ; 16(27): e1907691, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32511894

RESUMO

The continuous progress of printing technologies over the past 20 years has fueled the development of a plethora of applications in materials sciences, flexible electronics, and biotechnologies. More recently, printing methodologies have started up to explore the world of Artificial Biology, offering new paradigms in the direct assembly of Artificial Biosystems (small condensates, compartments, networks, tissues, and organs) by mimicking the result of the evolution of living systems and also by redesigning natural biological systems, taking inspiration from them. This recent progress is reported in terms of a new field here defined as Printing Biology, resulting from the intersection between the field of printing and the bottom up Synthetic Biology. Printing Biology explores new approaches for the reconfigurable assembly of designed life-like or life-inspired structures. This work presents this emerging field, highlighting its main features, i.e., printing methodologies (from 2D to 3D), molecular ink properties, deposition mechanisms, and finally the applications and future challenges. Printing Biology is expected to show a growing impact on the development of biotechnology and life-inspired fabrication.


Assuntos
Materiais Biomiméticos , Biotecnologia , Biologia Sintética , Materiais Biomiméticos/química , Materiais Biomiméticos/normas , Biotecnologia/tendências , Impressão Tridimensional , Biologia Sintética/tendências
6.
Phys Chem Chem Phys ; 22(16): 8344-8352, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32259171

RESUMO

In this paper, we developed different three-component organic heterojunction structures supported by PET/ITO substrates with the aim to study the possible synergies and/or compromises between charge transfer (CT) and energy transfer (ET) processes in organic solar cells (OSCs). As components, we employed poly(3-hexylthiophene-2,5-diyl) (P3HT; donor), [6,6]-phenyl-C61-butyric acid methyl ester (PCBM; acceptor) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) that is known to give good ET to P3HT. At first, we observed that in a planar heterojunction (PHJ) solar cell, F8BT has to be properly located in between P3HT and PCBM to get a cascade energy level configuration allowing for a better CT and power conversion efficiency. Then, we observed that by producing a P3HT:F8BT blend, the energy transfer process can be improved in the P3HT:F8BT/PCBM active layer. This may enable decreasing the thickness of the active layer while maintaining a similar PCE that is very interesting for the development of transparent OSCs. However, the P3HT:F8BT blend limits the P3HT-PCBM CT with respect to a P3HT/F8BT/PCBM PHJ, showing that a compromise between CT and ET is needed to get a higher PCE or higher transparency. By the above approach, in this paper, we developed highly transparent heterojunction structures for solar cell devices with PCEs comparable to those observed from the colorful reference P3HT/PCBM PHJ solar cells on PET/ITO substrates.

7.
Molecules ; 25(9)2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32397234

RESUMO

Organic Photovoltaics (OPVs) based on Bulk Heterojunction (BHJ) blends are a mature technology. Having started their intensive development two decades ago, their low cost, processability and flexibility rapidly funneled the interest of the scientific community, searching for new solutions to expand solar photovoltaics market and promote sustainable development. However, their robust implementation is hampered by some issues, concerning the choice of the donor/acceptor materials, the device thermal/photo-stability, and, last but not least, their morphology. Indeed, the morphological profile of BHJs has a strong impact over charge generation, collection, and recombination processes; control over nano/microstructural morphology would be desirable, aiming at finely tuning the device performance and overcoming those previously mentioned critical issues. The employ of compatibilizers has emerged as a promising, economically sustainable, and widely applicable approach for the donor/acceptor interface (D/A-I) optimization. Thus, improvements in the global performance of the devices can be achieved without making use of more complex architectures. Even though several materials have been deeply documented and reported as effective compatibilizing agents, scientific reports are quite fragmentary. Here we would like to offer a panoramic overview of the literature on compatibilizers, focusing on the progression documented in the last decade.


Assuntos
Modelos Químicos , Energia Solar
8.
J Vasc Bras ; 19: e20180131, 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-34178046

RESUMO

We report a case of inferior vena cava filter perforation immediately after filter implantation, recognized intraoperatively in a patient undergoing laparotomy for resection of locally advanced ovarian cancer. We describe an alternative approach with strut resection, less invasive than filter removal, enabling the device to be maintained and bleeding to be controlled.


Relatamos um caso de perfuração de veia cava inferior imediatamente após o implante de um filtro. A complicação foi reconhecida no intraoperatório de uma laparotomia para ressecção de um câncer de ovário localmente avançado. Descrevemos uma abordagem alternativa, menos invasiva do que a remoção do filtro, consistindo na ressecção das hastes do dispositivo. Essa abordagem permitiu a manutenção do filtro e o controle efetivo do sangramento.

9.
J Vasc Surg ; 69(6): 1880-1888, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30591301

RESUMO

OBJECTIVE: Vascular invasion is no longer considered to be an absolute contraindication to tumor removal, and complex reconstructions are part of the daily activity of vascular surgeons in specialized cancer centers. Our aim was to report a single-center experience of complex vascular reconstructions involving en bloc resection of tumors and patients' long-term survival and graft patency outcomes. To the best of our knowledge, this is the largest report of vascular reconstructions published to date, with the longest follow-up. METHODS: Between September 1997 and January 2016, there were 91 patients who underwent 92 arterial and 47 venous reconstruction procedures in this retrospective cohort study. Long-term survival and patency outcomes were analyzed for all study patients and individually assessed in different body segments (head and neck, thorax, upper limbs, abdomen, and lower limbs). RESULTS: The estimated mean and median follow-up times were 112.66 and 100 months, respectively. The 24- and 60-month survival estimates for the patients overall were 55.3% and 31.1%, respectively. Survival estimates were significantly lower in the head and neck cases compared with the other body segments. The primary arterial patency rates at 24 and 60 months were 96.7% and 84.9%, respectively, and they were similar in all body segments. The venous patency rates were 71.4% and 64.2% at 24 and 60 months, respectively. Seven cases (7.6%) of arterial vascular complications were observed. CONCLUSIONS: Vascular reconstruction performed in conjunction with oncologic resection is a feasible treatment option for tumors with vessel involvement. When surgery is performed in specialized centers, low perioperative morbidity and long-term patency rates are expected irrespective of the vascular territory undergoing intervention.


Assuntos
Vasos Sanguíneos/patologia , Neoplasias/cirurgia , Procedimentos de Cirurgia Plástica , Procedimentos Cirúrgicos Vasculares , Adolescente , Adulto , Idoso , Brasil , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Neoplasias/mortalidade , Neoplasias/patologia , Complicações Pós-Operatórias/etiologia , Procedimentos de Cirurgia Plástica/efeitos adversos , Procedimentos de Cirurgia Plástica/mortalidade , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Procedimentos Cirúrgicos Vasculares/mortalidade , Adulto Jovem
10.
Langmuir ; 35(14): 4936-4945, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30875226

RESUMO

Inkjet printing is here employed for the first time as a method to produce femtoliter-scale oil droplets dispersed in water. In particular, picoliter-scale fluorinated oil (FC40) droplets are printed in the presence of perfluoro-1-octanol surfactant at a velocity higher than 5 m/s. Femtoliter-scale oil droplets in water are spontaneously formed through a fragmentation process at the water/air interface using minute amounts of nonionic surfactant (down to 0.003% v/v of Tween 80). This fragmentation occurs by a Plateau-Rayleigh mechanism at a moderately high Weber number (101). A microfluidic chip with integrated microelectrodes allows droplets characterization in terms of number and diameter distribution (peaked at about 3 µm) by means of electrical impedance measurements. These results show an unprecedented possibility to scale oil droplets down to the femtoliter scale, which opens up several perspectives for a tailored oil-in-water emulsion fabrication for drug encapsulation, pharmaceutic preparations, and cellular biology.

11.
Chemistry ; 24(47): 12105-12106, 2018 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-30088832

RESUMO

Young again: A second edition of this special issue has been assembled to honor both the recent participants of the European Young Chemist Award (EYCA) as well as young and emerging scientists from around the world.

12.
Chemistry ; 24(65): 17164-17169, 2018 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-30427080

RESUMO

Young traditions: The 2018 European Young Chemist Award competition was held in Liverpool during the 7th EuCheMS Chemistry Congress continuing the tradition of showcasing and recognizing the excellent research being carried out by young scientists working in the chemical sciences.

13.
Ann Vasc Surg ; 47: 85-89, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28947219

RESUMO

BACKGROUND: There are only 3 studies comparing the efficacy of 2 different types of lock used in totally implantable catheters regarding occlusion or reflux dysfunction. The present study contains the largest published casuistry (862 patients) and is the only one that analyzes 3 parameters: occlusion, reflux dysfunction, and flow dysfunction. METHODS: This was a retrospective study of patients operated at a large oncology center and followed up in the outpatient clinic between 2007 and 2015. The patients were divided into 2 groups according to the type of lock: the Hep group (heparine), whose lock was composed of saline solution 0.9% with heparin (100 IU/mL) and the SS group (saline solution), whose lock was composed of saline solution 0.9%. RESULTS: The Hep group was composed of 270 patients (31%) and the SS group of 592 patients (69%). Regarding occlusion, there were 8 cases in the Hep group (2.96%) and 8 in the SS group (1.35%; P = 0.11); in relation to reflux dysfunction, there were 8 cases in the Hep group (2.96%) and 8 in the SS group (1.35%; P = 0.11); in relation to flow dysfunction, there was 1 case in the Hep group (0.37%) and 4 cases in the SS group (0.68%; P = 1). CONCLUSIONS: There was no statistically significant difference between the groups regarding occlusion, reflux dysfunction, and flow dysfunction.


Assuntos
Anticoagulantes , Obstrução do Cateter , Cateterismo Venoso Central/métodos , Cateteres de Demora , Heparina , Cloreto de Sódio , Adulto , Idoso , Idoso de 80 Anos ou mais , Cateterismo Venoso Central/instrumentação , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
14.
Chemistry ; 22(48): 17053-17058, 2016 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-27778396

RESUMO

The future is in good hands! The European Young Chemist Award for 2016 was awarded at the 6th EuCheMS Chemistry Congress in Seville. Reflections on the participants and their chemistry from the Convener of the event, Professor Bruno Pignataro, are given in the Guest Editorial.

15.
Ann Vasc Surg ; 30: 159-65, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26541965

RESUMO

BACKGROUND: The aim of this study was to analyze the outcomes of oncologic patients with associated aneurysm of the abdominal aorta (AAA), treated at a specialized cancer (Ca) hospital more than a 10-year period. METHODS: This was a retrospective study, and the data were obtained from our institution's prospective database. Between September 2003 and 2013, a total of 36 consecutive patients with AAA in association with Ca underwent surgical repair. Of these, 9 patients were excluded because the Ca treatment was performed at another service. Most of the patients were male (22) and the most frequent form of neoplasia was prostate Ca. Surgery for AAA repair was performed after the Ca treatment in 19 cases, before Ca treatment in 7 cases and concomitantly in 1 case. The intraoperative characteristics, treatment technique used, complications, patients' clinical evolution, and survival outcomes were analyzed. RESULTS: Endovascular aneurysm repair (EVAR) was used in 19 cases (70.4%) and conventional open repair (OR) in 8 cases (29.6%). Surgical treatment was uneventful in 19 cases, however, when present, postoperative complications occurred more frequently with EVAR (36.84% vs. 12.5%). There were no cases of death related to the aneurysm surgery. Most of the patients in both groups were alive at the end of the study. The probability of survival in our study was 65.8% at 3 years and 53% at 5 years, with no statistically significant difference between the EVAR and OR groups. The main cause of death was progression of the neoplastic disease. CONCLUSIONS: Patients who present Ca in association with AAA benefit from surgical treatment of both conditions, simultaneously or not. In these cases, it is important for the treatment to be individualized, and the disease of greater severity should be treated first. The endovascular and conventional open techniques were shown to be equivalent.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular , Procedimentos Endovasculares , Neoplasias/complicações , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/mortalidade , Aneurisma da Aorta Abdominal/patologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Neoplasias/patologia , Neoplasias/cirurgia , Estudos Retrospectivos , Stents , Taxa de Sobrevida , Resultado do Tratamento
16.
J Vasc Surg ; 62(1): 143-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26115921

RESUMO

BACKGROUND: Limb-sparing procedures are currently considered the standard treatment for lower limb soft tissue sarcoma (STS). Surgical excision combined with vascular resection may be necessary to provide an adequate safety margin and to improve the oncologic outcomes. In this scenario, vascular reconstruction is required to preserve limb function. We evaluated the long-term patency and survival outcomes of arterial and venous reconstruction after resecting lower limb STS in the largest single-center case series to date. METHODS: Between November 1995 and July 2014, 25 patients with lower limb STS and vascular invasion underwent surgical resection followed by arterial or venous reconstruction. Patients were followed up at regular outpatient visits, at which clinical examinations and duplex ultrasound mapping were performed to assess graft patency. RESULTS: A total of 44 revascularization procedures were performed. The median follow-up time for the arterial and venous groups combined was 25.2 months (range, 0.26-225.6 months). The 5-year survival probability was 42.1%. The graft occlusion rate was significantly higher after reconstruction with synthetic grafts than after reconstruction with saphenous vein substitutes (P = .02). The occlusion rate was not significantly different between arterial reconstruction and venous reconstruction (P > .05). CONCLUSIONS: Arterial and venous reconstruction is feasible after surgical resection of lower limb STS. Vascular reconstruction provides favorable long-term patency outcomes and low complication rates, allowing limb preservation and disease control in a select group of patients. Vascular reconstruction using venous grafts had a significantly higher patency rate than reconstruction with artificial venous substitutes.


Assuntos
Implante de Prótese Vascular , Extremidade Inferior/irrigação sanguínea , Procedimentos de Cirurgia Plástica , Veia Safena/transplante , Sarcoma/cirurgia , Neoplasias de Tecidos Moles/cirurgia , Adolescente , Adulto , Idoso , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/mortalidade , Brasil , Estudos de Viabilidade , Feminino , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/fisiopatologia , Humanos , Estimativa de Kaplan-Meier , Salvamento de Membro , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Procedimentos de Cirurgia Plástica/efeitos adversos , Procedimentos de Cirurgia Plástica/mortalidade , Estudos Retrospectivos , Fatores de Risco , Veia Safena/fisiopatologia , Sarcoma/mortalidade , Sarcoma/patologia , Neoplasias de Tecidos Moles/mortalidade , Neoplasias de Tecidos Moles/patologia , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia Doppler Dupla , Grau de Desobstrução Vascular , Adulto Jovem
17.
Chemistry ; 20(50): 16405-10, 2014 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-25393799

RESUMO

The future's bright! The European Young Chemist Award for 2014 was awarded at the 5th EuCheMS Chemistry Congress in Instanbul. Impressions and reflections from the Convener of the event, Professor Bruno Pignataro, are given in the Guest Editorial.

18.
Ann Vasc Surg ; 28(2): 351-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24094470

RESUMO

BACKGROUND: Fully implantable catheters are important for oncology treatments. They can be functionally categorized as valved or nonvalved. Theoretically, a valve prevents spontaneous blood reflux into the catheter, reducing the incidence of complications. We sought to compare the results from the implantation of valved and nonvalved fully implantable 8-French catheters inserted via ultrasound-guided puncture in cancer patients undergoing chemotherapy treatment. METHODS: A retrospective analysis of 100 patients who underwent long-term catheter implantation guided by ultrasound was performed looking for early (≤30 days) or late (≥90 days) complications. They were evaluated regarding the use of valved or nonvalved catheter and assessed on univariate model. RESULTS: The only early complication (hematoma) was identified in the valved group. Twenty-two late complications were identified (72.72% in the valved group and 27.27% in the nonvalved group; P = 0.009). Blood reflux dysfunction, which occurred in 12 patients in the valved and none in the nonvalved devices group, was the only complication with an incidence that was significantly different between the groups. CONCLUSION: Fully implantable valved catheters with Groshong (Bard Medical Division, Covington, GA) valves have a higher rate of blood reflux dysfunction compared with nonvalved catheters, but this did not interfere with the efficacy of the treatment.


Assuntos
Antineoplásicos/administração & dosagem , Cateterismo Venoso Central/instrumentação , Cateteres de Demora , Ultrassonografia de Intervenção , Dispositivos de Acesso Vascular , Administração Intravenosa , Adulto , Idoso , Idoso de 80 Anos ou mais , Cateterismo Venoso Central/efeitos adversos , Desenho de Equipamento , Feminino , Hematoma/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Punções , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
19.
Int J Biol Macromol ; 260(Pt 2): 129452, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38228201

RESUMO

Ageing of paper is a complex process of great relevance for application purposes because of its widespread use as support for information storage in books and documents, and as common low-cost and green packaging material, to name a few. A key factor in paper ageing is the oxidation of cellulose, a macromolecule of natural origin that constitutes the main chemical component of paper. Such a complex process results in changes in the cellulose polymeric chains in chemical and structural properties. The scope of this work is to explore the effects of oxidation of cellulose as one of the principal mechanisms of ageing of paper using a fluorescence-based approach. To this aim, fluorescence-lifetime imaging microscopy (FLIM) measurements on pure cellulose samples stained using Carbotrace 680 dye were performed, and data were analyzed by phasor approach. The comparison with results from conventional techniques allowed to map paper microstructure as a function of the sample oxidation degree correlating the fluorescence-lifetime changes to cellulose oxidation. A two-step oxidation kinetics that produced specific modification in paper organization was highlighted indicating that FLIM measurements using Carbotrace 680 dye may provide a simple tool to obtain information on the oxidation process also adding spatial information at sub-micrometric scale.


Assuntos
Celulose , Polímeros , Microscopia de Fluorescência/métodos , Cinética
20.
ACS Chem Neurosci ; 15(15): 2916-2924, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39036818

RESUMO

Several studies have highlighted the presence of nitration damage following neuroinflammation in Alzheimer's disease (AD). Accordingly, post-transcriptional modifications of ß-amyloid (Aß), including peptide nitration, have been explored as a marker of the disease. However, the implications of Aß nitration in terms of aggregation propensity and neurotoxicity are still debated. Here, we show new data obtained using a photoactivatable peroxynitrite generator (BPT-NO) to overcome the limitations associated with chemical nitration methods. We found that the photoactivation of BPT-NO with the highly biocompatible red light selectively induces the nitration of tyrosine 10 of freshly solubilized full-length Aß1-42. Photonitrated Aß1-42 was, therefore, investigated for aggregation states and functions. It resulted that photonitrated Aß1-42 did not aggregate into small oligomers but rather self-assembled into large amorphous aggregates. When tested on neuronal-like SH-SY5Y cells and microglial C57BL/6 BV2 cells, photonitrated Aß1-42 showed to be free of neurotoxicity and able to induce phagocytic microglia cells. We propose that light-controlled nitration of the multiple forms in which Aß occurs (i.e., monomers, oligomers, fibrils) could be a tool to assess in real-time the impact of tyrosine nitration on the amyloidogenic and toxic properties of Aß1-42.


Assuntos
Peptídeos beta-Amiloides , Luz , Fragmentos de Peptídeos , Tirosina , Peptídeos beta-Amiloides/metabolismo , Tirosina/metabolismo , Tirosina/análogos & derivados , Tirosina/química , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/toxicidade , Humanos , Animais , Microglia/metabolismo , Microglia/efeitos dos fármacos , Ácido Peroxinitroso/metabolismo , Camundongos , Agregados Proteicos/fisiologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Neurônios/metabolismo , Neurônios/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA