456 research outputs found

    Edible cellulose-based conductive composites for triboelectric nanogenerators and supercapacitors

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    Edible electronics will enable systems that can be safely ingested and degraded in the human body after completing their function, such as sensing physiological parameters or biological markers in the gastrointestinal tract, without risk of retention or need of recollection. The same systems are potentially suitable for directly tagging food, monitoring its quality, and developing edible soft actuators control and sensing abilities. Designing appropriate edible power sources is critical to turn such a vision into real opportunities. We propose electrically conductive edible composites based on ethylcellulose and activated carbon as enabling materials for energy harvesting and storage. Free-standing, phase-separated bi-layered films, insulating at the top and with low electrical resistivity (∼10 Ω cm) at the bottom, were produced with a scalable single-step process. Food additives can tune the mechanical and triboelectrical properties of the proposed edible films. We demonstrated their successful operation as electropositive elements in organic triboelectric nanogenerators (TENGs) and as electrodes in fully edible supercapacitors (SC). The TENGs showed ∼60 V peak voltage (root mean square power density ∼2.5 μW cm−2 at 5 Hz), while the SC achieved an energy density of 3.36 mW h g−1, capacity of ∼ 9 mAh g−1, and stability for more than 1000 charge-discharge cycles. These results show that the combination of ethyl cellulose and activated carbon, and the control over their mixture, allow on-demand edible devices for energy generation and storage, serving future edible and green electronics scenarios

    Trends in the Postmortem Diagnosis of Opportunistic Invasive Fungal Infections in Patients With AIDS

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    Abstract We retrospectively evaluated autopsy-proven invasive fungal infections (IFIs) in patients with AIDS who died between 1984 and 2002. IFIs were identified in 297 (18.2%) of 1,630 autopsies. Their prevalence significantly decreased over time (from 25.0% in 1984–1988 to 15% in 1998–2002; P = .004), mainly owing to a significant decrease in pneumocystosis (P = .017) and cryptococcosis (P = .003), whereas the prevalence of aspergillosis and histoplasmosis remained relatively stable and of candidiasis and zygomycosis tended to increase in the last years (P = .028 and P = .042, respectively). IFIs were suspected or confirmed during life in only 46.8% of the cases; this proportion did not vary significantly over time (P = .320). The infections contributed to the deaths of 103 patients (34.7%), and their global impact on mortality was 6.3%. Of fatal cases, 38 (36.9%) were characterized by missed antemortem diagnoses, 17 (45%) of which met Goldman criteria for class I errors. The epidemiology of IFIs in patients with AIDS is evolving and not completely mirrored by clinical diagnoses or current diagnostic methods. Our results confirm the valuable role of autopsy data, even with highly effective therapies and advanced technologies

    Millet Fermented by Different Combinations of Yeasts and Lactobacilli: Effects on Phenolic Composition, Starch, Mineral Content and Prebiotic Activity

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    Millet is the sixth-highest yielding grain in the world and a staple crop for millions of people. Fermentation was applied in this study to improve the nutritional properties of pearl millet. Three microorganism combinations were tested: Saccharomyces boulardii (FPM1), Saccharomyces cerevisiae plus Campanilactobacillus paralimentarius (FPM2) and Hanseniaspora uvarum plus Fructilactobacillus sanfranciscensis (FPM3). All the fermentation processes led to an increase in minerals. An increase was observed for calcium: 254 ppm in FPM1, 282 ppm in FPM2 and 156 ppm in the unfermented sample. Iron increased in FPM2 and FPM3 (approx. 100 ppm) with respect the unfermented sample (71 ppm). FPM2 and FPM3 resulted in richer total phenols (up to 2.74 mg/g) compared to the unfermented sample (2.24 mg/g). Depending on the microorganisms, it was possible to obtain different oligopeptides with a mass cut off <= 10 kDalton that was not detected in the unfermented sample. FPM2 showed the highest resistant starch content (9.83 g/100 g) and a prebiotic activity on Bifidobacterium breve B632, showing a significant growth at 48 h and 72 h compared to glucose (p < 0.05). Millet fermented with Saccharomyces cerevisiae plus Campanilactobacillus paralimentarius can be proposed as a new food with improved nutritional properties to increase the quality of the diet of people who already use millet as a staple food

    Prevention of Recurrent Benign Paroxysmal Positional Vertigo: The Role of Combined Supplementation with Vitamin D and Antioxidants

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    Benign paroxysmal positional vertigo (BPPV) usually has a favorable course, although it is possible to observe BPPV with a high recurrence rate. Previous studies suggested that vitamin D deficiency might affect BPPV recurrences, and oxidative stress might play a complementary role in BPPV pathogenesis. This multicentric trial aimed to evaluate the effectiveness of oral nutritional supplementation with a compound of alpha-lipoic acid, Carnosine, and Zinc (LICA (R) (Difass International, Coriano (RN), Italy)), vitamins of group B and vitamin D in preventing BPPV recurrences. A total of 128 patients with high recurrence-BPPV were randomized in three arms: Arm 1 consisted of subjects with "insufficient" or "deficient" vitamin D blood levels, treated with daily oral supplementation of LICA (R), vitamins of group B and vitamin D3 (800 UI), Arm 2 included BPPV subjects with "sufficient" vitamin D who did not receive any nutritional support, and Arm 3 included subjects with a "sufficient" serum concentration of vitamin D who received supplementation with a compound of LICA (R) and Curcumin. After six months of follow-up, a significant reduction of BPPV relapses compared to the baseline was found only in Arm 1 (-2.32, 95% CI: 3.41-1.62, p-value < 0.0001). Study results suggested that oral nutritional supplementation with vitamin D3 plus antioxidants can prevent relapses in patients suffering from high recurrence-BPPV

    A Regulatory Mechanism Involving TBP-1/Tat-Binding Protein 1 and Akt/PKB in the Control of Cell Proliferation

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    TBP-1 /Tat-Binding Protein 1 (also named Rpt-5, S6a or PSMC3) is a multifunctional protein, originally identified as a regulator of HIV-1-Tat mediated transcription. It is an AAA-ATPase component of the 19S regulative subunit of the proteasome and, as other members of this protein family, fulfils different cellular functions including proteolysis and transcriptional regulation. We and others reported that over expression of TBP-1 diminishes cell proliferation in different cellular contexts with mechanisms yet to be defined. Accordingly, we demonstrated that TBP-1 binds to and stabilizes the p14ARF oncosuppressor increasing its anti-oncogenic functions. However, TBP-1 restrains cell proliferation also in the absence of ARF, raising the question of what are the molecular pathways involved. Herein we demonstrate that stable knock-down of TBP-1 in human immortalized fibroblasts increases cell proliferation, migration and resistance to apoptosis induced by serum deprivation. We observe that TBP-1 silencing causes activation of the Akt/PKB kinase and that in turn TBP-1, itself, is a downstream target of Akt/PKB. Moreover, MDM2, a known Akt target, plays a major role in this regulation. Altogether, our data suggest the existence of a negative feedback loop involving Akt/PKB that might act as a sensor to modulate TBP-1 levels in proliferating cells

    Proteolysis-Dependent Remodeling of the Tubulin Homolog FtsZ at the Division Septum in \u3ci\u3eEscherichia coli\u3c/i\u3e

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    During bacterial cell division a dynamic protein structure called the Z-ring assembles at the septum. The major protein in the Z-ring in Escherichia coli is FtsZ, a tubulin homolog that polymerizes with GTP. FtsZ is degraded by the two-component ATP-dependent protease ClpXP. Two regions of FtsZ, located outside of the polymerization domain in the unstructured linker and at the C-terminus, are important for specific recognition and degradation by ClpXP. We engineered a synthetic substrate containing green fluorescent protein (Gfp) fused to an extended FtsZ C-terminal tail (residues 317–383), including the unstructured linker and the C-terminal conserved region, but not the polymerization domain, and showed that it is sufficient to target a non-native substrate for degradation in vitro. To determine if FtsZ degradation regulates Z-ring assembly during division, we expressed a full length Gfp-FtsZ fusion protein in wild type and clp deficient strains and monitored fluorescent Z-rings. In cells deleted for clpX or clpP, or cells expressing protease-defective mutant protein ClpP(S97A), Z-rings appear normal; however, after photobleaching a region of the Z-ring, fluorescence recovers ~70% more slowly in cells without functional ClpXP than in wild type cells. Gfp-FtsZ(R379E), which is defective for degradation by ClpXP, also assembles into Z-rings that recover fluorescence ~2-fold more slowly than Z-rings containing Gfp-FtsZ. In vitro, ClpXP cooperatively degrades and disassembles FtsZ polymers. These results demonstrate that ClpXP is a regulator of Z-ring dynamics and that the regulation is proteolysis-dependent. Our results further show that FtsZ-interacting proteins in E. coli fine-tune Z-ring dynamics
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