Polystyrene nanoplastics affect the human ubiquitin structure and ubiquitination in cells: a high-resolution study.

Humans are estimated to consume several grams per week of nanoplastics (NPs) through exposure to a variety of contamination sources. Nonetheless, the effects of these polymeric particles on living systems are still mostly unknown. Here, by means of CD, NMR and TEM analyses, we describe at an atomic resolution the interaction of ubiquitin with polystyrene NPs (PS-NPs), showing how a hard protein corona is formed. Moreover, we report that in human HeLa cells exposure to PS-NPs leads to a sensible reduction of ubiquitination. Our study overall indicates that PS-NPs cause significant structural effects on ubiquitin, thereby influencing one of the key metabolic processes at the base of cell viability.

PET/MRI for staging patients with Hodgkin lymphoma: equivalent results with PET/CT in a prospective trial.

To compare FDG-PET/unenhanced MRI and FDG-PET/diagnostic CT in detecting infiltration in patients with newly diagnosed Hodgkin lymphoma (HL). The endpoint was equivalence between PET/MRI and PET/CT in correctly defining the revised Ann Arbor staging system. Seventy consecutive patients with classical-HL were prospectively investigated for nodal and extra-nodal involvement during pretreatment staging with same-day PET/CT and PET/MRI. Findings indicative of malignancy with the imaging procedures were regarded as lymphoma infiltration; in case of discrepancy, positive-biopsy and/or response to treatment were evidenced as lymphoma. Sixty of the 70 (86%) patients were evaluable having completed the staging program. Disease staging based on either PET/MRI or PET/CT was correct for 54 of the 60 patients (90% vs. 90%), with difference between proportions of 0.0 (95% CI, -9 to 9%; P=0.034 for the equivalence test). As compared with reference standard, invasion of lymph nodes was identified with PET/MRI in 100% and with PET/CT in 100%, of the spleen with PET/MRI in 66% and PET/CT in 55%, of the lung with PET/MRI in 60% and PET/CT in 100%, of the liver with PET/MRI in 67% and PET/CT in 100%, and of the bone with PET/MRI in 100% and PET/CT in 50%. The only statistically significant difference between PET/MRI and PET/CT was observed in bony infiltration detection rates. For PET/CT, iodinate contrast medium infusions' average was 86 mL, and exposure to ionizing radiation was estimated to be 4-fold higher than PET/MRI. PET/MRI is a promising safe new alternative in the care of patients with HL.

Optimization of dye adsorption capacity and mechanical strength of chitosan aerogels through crosslinking strategy and graphene oxide addition.

Chitosan (CS) aerogels were prepared by freeze-drying as potential adsorbents for water purification, and the effect of the strategy of crosslinking was investigated by varying the amount of crosslinker (glutaraldehyde) and the sequence of steps for the preparation of the aerogel. Two procedures were compared, in which the crosslinking step was carried out before or after the freeze-drying of the starting CS solution. When crosslinking was postponed after the freeze-drying step, the adsorption capacity towards an anionic dye, such as indigo carmine, considerably increased (up to +45%), reaching values as high as 534.4 ± 30.5 mg g-1. The same crosslinking strategy ensured a comparable improvement also in nanocomposite aerogels containing graphene oxide (GO), which was added to enhance the mechanical strength and provide adsorption capacity towards cationic dyes. Besides possessing good mechanical strength (compressive modulus higher than 1 MPa), the CS/GO aerogels were able to bind also cationic pollutants such as methylene blue. The maximum uptake capacity increased from 4.3 ± 1.6 to 168.6 ± 9.6 mg of cationic dye adsorbed per gram of adsorbent with respect to pristine CS aerogels.

Ultra-short term HRV features as surrogates of short term HRV: a case study on mental stress detection in real life.

BACKGROUND: This paper suggests a method to assess the extent to which ultra-short Heart Rate Variability (HRV) features (less than 5 min) can be considered as valid surrogates of short HRV features (nominally 5 min). Short term HRV analysis has been widely investigated for mental stress assessment, whereas the validity of ultra-short HRV features remains unclear. Therefore, this study proposes a method to explore the extent to which HRV excerpts can be shortened without losing their ability to automatically detect mental stress. METHODS: ECGs were acquired from 42 healthy subjects during a university examination and resting condition. 23 features were extracted from HRV excerpts of different lengths (i.e., 30 s, 1 min, 2 min, 3 min, and 5 min). Significant differences between rest and stress phases were investigated using non-parametric statistical tests at different time-scales. Features extracted from each ultra-short length were compared with the standard short HRV features, assumed as the benchmark, via Spearman's rank correlation analysis and Bland-Altman plots during rest and stress phases. Using data-driven machine learning approaches, a model aiming to detect mental stress was trained, validated and tested using short HRV features, and assessed on the ultra-short HRV features. RESULTS: Six out of 23 ultra-short HRV features (MeanNN, StdNN, MeanHR, StdHR, HF, and SD2) displayed consistency across all of the excerpt lengths (i.e., from 5 to 1 min) and 3 out of those 6 ultra-short HRV features (MeanNN, StdHR, and HF) achieved good performance (accuracy above 88%) when employed in a well-dimensioned automatic classifier. CONCLUSION: This study concluded that 6 ultra-short HRV features are valid surrogates of short HRV features for mental stress investigation.

Multiridge Method for Studying Ground-Deformation Sources: Application to Volcanic Environments.

Volcanic phenomena are currently monitored by the detection of physical and chemical observations. Generally, the ground deformation field is the most relevant shallow expression of the geometric and physical parameters variations in the magmatic reservoir. In this study, we propose a novel method for the direct estimation of the geometric parameters of sources responsible for volcanic ground deformation detected via the DInSAR technique. Starting with the biharmonic properties of the deformation field, we define an approach based on the Multiridge and ScalFun methods to achieve relevant information about both the positions and shapes of active sources, such as the Mogi source. Our methodology is definitely different from the methods currently used for modeling ground-deformation sources, mainly based on forward or inverse techniques. In fact, (i) it does not require any assumptions about the source type, and (ii) it is not influenced by the distribution of medium elastic parameters or (iii) the presence of high-frequency noise in the dataset. For synthetic cases, we accurately estimate the depth to the source within a 3% error. Finally, we study the real case of the Okmok volcano ground-deformation field and achieve results compatible with those in previous works.

Detection of mental stress due to oral academic examination via ultra-short-term HRV analysis.

Mental stress may cause cognitive dysfunctions, cardiovascular disorders and depression. Mental stress detection via short-term Heart Rate Variability (HRV) analysis has been widely explored in the last years, while ultra-short term (less than 5 minutes) HRV has been not. This study aims to detect mental stress using linear and non-linear HRV features extracted from 3 minutes ECG excerpts recorded from 42 university students, during oral examination (stress) and at rest after a vacation. HRV features were then extracted and analyzed according to the literature using validated software tools. Statistical and data mining analysis were then performed on the extracted HRV features. The best performing machine learning method was the C4.5 tree algorithm, which discriminated between stress and rest with sensitivity, specificity and accuracy rate of 78%, 80% and 79% respectively.

Overexpression of Upf1p compensates for mitochondrial splicing deficiency independently of its role in mRNA surveillance.

In yeast the UPF1, UPF2 and UPF3 genes encode three interacting factors involved in translation termination and nonsense-mediated mRNA decay (NMD). UPF1 plays a central role in both processes. In addition, UPF1 was originally isolated as a multicopy suppressor of mitochondrial splicing deficiency, and its deletion leads to an impairment in respiratory growth. Here, we provide evidence that inactivation of UPF2 or UPF3, like that of UPF1, leads to an impairment in respiratory competence, suggesting that their products, Upf1p, Upf2p and Upf3p, are equivalently involved in mitochondrial biogenesis. In addition, however, we show that only Upf1p acts as a multicopy suppressor of mitochondrial splicing deficiency, and its activity does not require either Upf2p or Upf3p. Mutations in the conserved cysteine- and histidine-rich regions and ATPase and helicase motifs of Upf1p separate the ability of Upf1p to complement the respiratory impairment of a Deltaupf1 strain from its ability to act as a multicopy suppressor of mitochondrial splicing deficiency, indicating that distinct pathways express these phenotypes. In addition, we show that, when overexpressed, Upf1p is not detected within mitochondria, suggesting that its role as multicopy suppressor of mitochondrial splicing deficiency is indirect. Furthermore, we provide evidence that cells overexpressing certain upf1 alleles accumulate a phosphorylated isoform of Upf1p. Altogether, these results indicate that overexpression of Upf1p compensates for mitochondrial splicing deficiency independently of its role in mRNA surveillance, which relies on Upf1p-Upf2p-Upf3p functional interplay.

Diagnosis of deep venous thrombosis by use of soluble necrosis factor receptor.

The purpose of this clinical study was to find a relationship between soluble tumor necrosis factor (TNF) receptor, deep venous thrombosis (DVT), and pulmonary emboli (PE). Clinical diagnosis of deep venous thrombosis and pulmonary emboli is a major dilemma for the clinician. Most existing tests are technician dependent, are expensive, or require sophisticated equipment. Advances in molecular biology will permit investigation of the value of TNF receptor as a test for screening, diagnosis, and evolution of DVT and PE. Forty patients with diagnosis of DVT, documented by real-time ultrasound imaging, were the subject of this clinical study. Five cc of plasma from each patient was studied by enzyme-linked immunosorbent assay (Elisa) for measurement of soluble TNF receptor. Significantly increased concentration of plasma-soluble TNF receptor was present in patients with DVT as opposed to normal individuals. There was a close relationship between plasma concentration of soluble TNF receptor and evaluation of the disease. In this preliminary clinical study, it appears that plasma measurement of soluble TNF receptor could be used as a clinical test for diagnosis of DVT and PE.

The transcription of NAM7/UPF1 is enhanced in the absence of Cyp1p/Hap1p concomitant with the appearance of an ISF1-NAM7 cotranscript in Saccharomyces cerevisiae.

The two adjacent nuclear genes ISF1 and NAM7 cooperatively participate in mitochondrial functions. It is well known that Cyp1p(Hap1p) activates a number of genes involved in these same functions. We show in this paper that Cyp1p influences the transcriptional regulation of NAM7. In addition, a significant amount of ISF1-NAM7 cotranscript is observed in a cyp1 mutant context. An extensive analysis of the intergenic region which separates the two genes revealed 5' starts of the NAM7 transcripts, additional to those previously mapped. These new 5' starts overlap the 3' ends of ISF1. We propose that NAM7 is under the control of a negative Cyp1p-dependent regulator and that its absence favours a transcriptional read-through which results in the ISF1-NAM7 cotranscript we have identified.

A real-time FFT analyser for monitoring muscle fatigue.

The TMS 32010 system for a real-time muscle fatigue monitor is described; it is based on mean frequency shift in the electromyographic signal (EMG). The mean frequency of the EMG is obtained, in real time, from its power spectrum, with a 2 Hz resolution. This is made possible by combining novel hardware and software.

Activity of 2,4-diaminoquinazoline compounds against Candida species.

Forty recent clinical isolates of three different Candida sp. were tested in the microtiter system for susceptibility to two new 2,4-diaminoquinazoline (DAQ) compounds, amphotericin B and flucytosine. The two DAQ preparations showed activity similar to amphotericin B and flucytosine. The geometric mean minimal inhibitory concentrations for these four drugs were as follows: DAQ 1A, 0.64 mug/ml; DAQ 2A, 1.39 mug/ml; amphotericin B, 1.03 mug/ml; and flucytosine, 0.72 mug/ml. An additional seven DAQ compounds were tested but showed less or no activity against 17 Candida isolates. Forty-eight-hour viability studies with DAQ 2A alone or in combination with amphotericin B, flucytosine, or sulfamethoxazole were carried out with one isolate of intermediate susceptibility to each of these agents except sulfamethoxazole. For this isolate the combination of DAQ 2A and sulfamethoxazole was synergistic, and the combination of DAQ 2A and AMB was either synergistic or additive, whereas the combination of DAQ 2A and flucytosine was antagonistic. Although regrowth of cultures exposed to DAQ 2A was noted over a 48-h period, neither degradation of the drug nor development of resistance to the drug could be detected. Swiss white mice receiving DAQ 1A at a dose of 6 mg/kg for 5 days showed no obvious signs of toxicity, including weight loss.