3,248 research outputs found

    Biological systems interact with Engineered NanoMaterials (ENMs): Possible environmental risks

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    There is a growing and controversial public debate on the potential risk of NanoMaterials (NMs) to living organisms, including humans. In particular, the processes of dispersion and bioaccumulation of Engineered NanoMaterials (ENMs) into the environment are poorly investigated. Biological systems interact with ENMs in a very complex dynamic way whose comprehension is still at its infancy. Thus the evaluation of the environmental impact of ENMs may be useful to minimize or eliminate ENMs toxicity and/or ecotoxicity, and to help authorities to draw directives and regulations for a safe production and use of ENMs. Here we briefly review biotoxicity and environmental risks of ENMs (like carbon- and metalnanoparticles) reporting also our experience in the cytotoxicity of carbon (C) and silver (Ag) NanoParticles (NPs) on HeLa cells and nanoecotoxicity on Paracentrotus lividus

    Perancangan Perbaikan Lintasan Produksi di Bengkel Pusat PT. Perkebunan Nusantara II

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    Salah satu indikator kinerja produksi dari industri manufaktur pembuatan lorry adalah waktu siklus yang diperlukan untuk menyelesaikan satu unit lorry. Waktu siklus pembuatan lorry pada lantai pabrik di Bengkel Pusat PT. Perkebunan Nusantara II pada umumnya lebih lama daripada waktu siklus yang seharusnya. Hal ini berkaitan dengan terjadinya waktu menunggu pada stasiun kerja perakitan lorry. Penelitian ini bertujuan untuk mengurangi waktu menunggu melalui upaya perbaikan pada lintasan produksi dengan menerapkan lean manufacturing, yaitu dengan menggunakan value stream mapping untuk mengidentifikasikan waste yang terjadi yaitu time waste. Hasil pemetaan dengan time stream mapping dilihat bahwa waktu siklus pembuatan satu unit lorry adalah 1538.457 menit dengan waktu menunggu hasil pengeboran di stasiun perakitan selama 942.731 menit. Perbaikan yang diusulkan adalah penerapan lean manufacturing melalui perbaikan lintasan produksi dengan mengubah lintasan pengeboran untuk mengisi Work In Process (WIP) plat samping lorry yang dibutuhkan pada stasiun kerja perakitan sehingga perakitan tidak harus menunggu selesainya pengeboran plat samping. Upaya perbaikan dengan mengadakan pengisian WIP untuk plat samping tersebut dapat mengurangi waktu menunggu selama dari 942.731 menit menjadi 429.036 menit atau 27.88 % sehingga waktu siklus pembuatan satu unit lorry berkurang dari 1538.457 menit menjadi 1109.421 menit

    A dual nozzle 3D printing system for super soft composite hydrogels

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    Due to their inability to sustain their own weight, 3D printing materials as soft as human tissues is challenging. Hereby we describe the development of an extrusion additive manufacturing (AM) machine able to 3D print super soft hydrogels with micro-scale precision. By designing and integrating new subsystems into a conventional extrusion-based 3D printer, we obtained hardware that encompasses a range of new capabilities. In particular, we integrated a heated dual nozzle extrusion system and a cooling platform in the new system. In addition, we altered the electronics and software of the 3D printer to ensure fully automatized procedures are delivered by the 3D printing device, and super-soft tissue mimicking parts are produced. With regards to the electronics, we added new devices to control the temperature of the extrusion system. As for the software, the firmware of the conventional 3D printer was changed and modified to allow for the flow rate control of the ink, thus eliminating overflows in sections of the printing path where the direction/speed changes sharply

    Synchronized onset of nuclear and cell surface modifications in U937 cells during apoptosis

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    In this study we investigated the relationship between nuclear and cell surface modifications (i.e. blebbing, phosphatidylserine [PS] and sugar residues exposure) in a monocytic cell line, U937, during apoptosis induced by oxidative stress (1mM H2O2) or inhibition of protein synthesis (10 mg/ml puromycin). Dying cells were simultaneously observed for nuclear modifications, presence of superficial blebs and plasma membrane alterations. Morphological analysis performed by conventional fluorescence microscopy, or by transmission and scanning electron microscopy showed that the courses of nuclear and membrane alterations occured concomitantly, but the phenotype was dependent on the stage of the apoptotic process and the type of apoptogenic inducer used. The progression of apoptosis in U937 cells beyond early stages resulted in the extensive formation of blebs which concomitantly lost some typical markers of apoptosis, such as PS and sugar residues. Therefore, the modality by which the nucleus condenses, or the amount and the pattern of distribution of PS on the cell surface were, for each cell line, strictly related to the apoptogenic inducer. The morphological data reported in the present paper should lead to a more precise quantification of apoptosis by improving the detection of apoptotic cells in vivo (i.e. in tissue, organs), which is a crucial point in the evaluation of efficiency of antiproliferative drugs, such as antiblastic or immunosuppressive compounds

    Persistent pulmonary congestion before discharge predicts rehospitalization in heart failure: a lung ultrasound study

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    BACKGROUND: B-lines evaluated by lung ultrasound (LUS) are the sonographic sign of pulmonary congestion, a major predictor of morbidity and mortality in patients with heart failure (HF). Our aim was to assess the prognostic value of B-lines at discharge to predict rehospitalization at 6 months in patients with acute HF (AHF). METHODS: A prospective cohort of 100 patients admitted to a Cardiology Department for dyspnea and/or clinical suspicion of AHF were enrolled (mean age 70 ± 11 years). B-lines were evaluated at admission and before discharge. Subjects were followed-up for 6-months after discharge. RESULTS: Mean B-lines at admission was 48 ± 48 with a statistically significant reduction before discharge (20 ± 23, p 15) (log rank χ(2) 20.5, p 15 before discharge (hazard ratio [HR] 11.74; 95 % confidence interval [CI] 1.30-106.16) was an independent predictor of events at 6 months. CONCLUSIONS: Persistent pulmonary congestion before discharge evaluated by ultrasound strongly predicts rehospitalization for HF at 6-months. Absence or a mild degree of B-lines identify a subgroup at extremely low risk to be readmitted for HF decompensation

    Plasma levels of oxidative stress markers, before and after BoNT/A Treatment, in chronic migraine

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    The pathophysiological mechanisms of migraine transformation are debated. Modifications of plasma oxidative stress biomarkers have been described in chronic migraine. OnabotulintoxinA (BoNT/A) treatment, approved for chronic migraine prophylaxis, possibly reduces pain neurotransmitters release and oxidative stress products. Aims of our study were to investigate differences in the levels of selected plasmatic oxidative stress biomarkers (Advanced Oxidation Protein Products (AOPP), Ferric Reducing Antioxidant Power (FRAP), Thiolic Groups (SH)) comparing chronic migraineurs (CM) and healthy controls (HC). We also explored possible clinical and biochemical modifications in the CM group after six months of treatment with BoNT/A. At the baseline, we found higher values of AOPP (p < 0.001), and lower values of SH (p < 0.001) and FRAP (p = 0.005) in the CM group. At the six-month follow-up we found a reduction of AOPP (p < 0.001) and an increase of FRAP (p < 0.001) and SH (p = 0.023) within the CM group. BoNT/A treatment improved migraine symptoms in the CM group. We confirmed previous reports of imbalanced antioxidant mechanisms in chronic migraine showing lower antioxidant capacities in patients than controls. BoNT/A improved the levels of plasma oxidative stress biomarkers and confirmed its role as an effective prophylactic treatment for CM. Other studies should investigate the potential antioxidant properties of BoNT/A treatment

    Photoelectrochemical properties of mesoporous NiOx deposited on technical FTO via nanopowder sintering in conventional and plasma atmospheres

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    Nanoporous nickel oxide (NiO x ) has been deposited with two different procedures of sintering (CS and RDS). Both samples display solid state oxidation at about 3.1 V vs Li+/Li. Upon sensitization of CS/RDS NiO x with erythrosine b (ERY), nickel oxide oxidation occurs at the same potential. Impedance spectroscopy revealed a higher charge transfer resistance for ERY-sensitized RDS NiO x with respect to sensitized CS NiO x . This was due to the chemisorption of a larger amount of ERY on RDS with respect to CS NiO x . Upon illumination the photoinduced charge transfer between ERY layer and NiO x could be observed only with oxidized CS. Photoelectrochemical effects of sensitized RDS NiO x were evidenced upon oxide reduction. With the addition of iodine RDS NiOx electrodes could give the reduction iodine → iodide in addition to the reduction of RDS NiO x . p-type dye sensitized solar cells were assembled with RDS NiO x photocathodes sensitized either by ERY or Fast Green. Resulting overall efficiencies ranged between 0.02 and 0.04 % upon irradiation with solar spectrum simulator (Iin : 0.1 W cm −2 )
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