Dynamical Systems Gradient method for solving nonlinear equations with monotone operators

A version of the Dynamical Systems Gradient Method for solving ill-posed nonlinear monotone operator equations is studied in this paper. A discrepancy principle is proposed and justified. A numerical experiment was carried out with the new stopping rule. Numerical experiments show that the proposed stopping rule is efficient. Equations with monotone operators are of interest in many applications.Comment: 2 figure

Fluorescent Neutron Track Detectors for Boron-10 Microdistribution Measurement in BNCT: A Feasibility Study

Boron Neutron-Capture Therapy (BNCT) is a form of radiation therapy that relies on the highly localized and enhanced biological effects of the 10B neutron capture (BNC) reaction products to selectively kill cancer cells. The efficacy of BNCT is, therefore, strongly dependent on the 10B spatial microdistribution at a subcellular level. Fluorescent Nuclear Track Detectors (FNTDs) could be a promising technology for measuring 10B microdistribution. They allow the measurement of the tracks of charged particles, and their biocompatibility allows cell samples to be deposited and grown on their surfaces. If a layer of borated cells is deposited and irradiated by a neutron field, the energy deposited by the BNC products and their trajectories can be measured by analyzing the corresponding tracks. This allows the reconstruction of the position where the measured particles were generated, hence the microdistribution of 10B. With respect to other techniques developed to measure 10B microdistribution, FNTDs would be a non-destructive, biocompatible, relatively easy-to-use, and accessible method, allowing the simultaneous measurement of the 10B microdistribution, the LET of particles, and the evolution of the related biological response on the very same cell sample. An FNTD was tested in three irradiation conditions to study the feasibility of FNTDs for BNCT applications. The FNTD allowed the successful measurement of the correct alpha particle range and mean penetration depth expected for all the radiation fields employed. This work proved the feasibility of FNTD in reconstructing the tracks of the alpha particles produced in typical BNCT conditions, thus the 10B microdistribution. Further experiments are planned at the University of Pavia’s LENA (Applied Nuclear Energy Laboratory) to test the final set-up coupling the FNTD with borated cell samples

Persistent homology to analyse 3D faces and assess body weight gain

In this paper, we analyse patterns in face shape variation due to weight gain. We propose the use of persistent homology descriptors to get geometric and topological information about the configuration of anthropometric 3D face landmarks. In this way, evaluating face changes boils down to comparing the descriptors computed on 3D face scans taken at different times. By applying dimensionality reduction techniques to the dissimilarity matrix of descriptors, we get a space in which each face is a point and face shape variations are encoded as trajectories in that space. Our results show that persistent homology is able to identify features which are well related to overweight and may help assessing individual weight trends. The research was carried out in the context of the European project SEMEOTICONS, which developed a multisensory platform which detects and monitors over time facial signs of cardio-metabolic risk

Oxidative Stress Status in Post Stroke Patients: Sex Differences

After a cerebral stroke insult, there is an overproduction of Reactive Oxygen Species (ROS), which overcome the antioxidant defenses, causing further tissues damage. The status of oxidative stress in stroke patients over time, particularly in those undergoing rehabilitation treatments, has been poorly investigated. We analyzed the oxidative stress status in 61 subacute stroke patients (33 females and 28 males) admitted to our rehabilitation center by measuring, in serum: hydroper-oxides levels (d-ROMs), antioxidant activity (BAP test), and the relative antioxidant capacity (OSI index). We also analyzed patients for glucose levels and lipid profile. In addition, we analyzed the correlation between oxidative stress status biomarkers and motor deficits, disability, and pain. Almost all patients showed high or very high levels of d-ROMs, while BAP levels were apparently in the reference range of normality. Females had lower BAP values (females: 2478 ± 379; males: 2765 ± 590; p = 0.034) and lower OSI index (females: 5.7 ± 1.9; males: 6.8 ± 1.9; p = 0.043). Moreover, in the male group, the correlation with motor impairment and disability showed a worsened motor performance when oxidative stress is higher. Female group, on the other hand, had an unexpected different trend of correlation, probably due to an unbalanced systemic oxidative stress. Further research is needed to see if sex differences in oxidative stress status in subacute stroke patients persist after rehabilitation

Electromagnetic biorezonance stimulation in the treatment of postoperative intestinal failure

Catedra de Chirurgie nr.2, USMF ”N.Testemițanu”, Clinica 2 Chirurgie «C.Țîbîrnă», SCM “Sf. Treime”, Chişinău, Moldova, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Insuficiența intestinală postoperatorie prezintă una din complicațiile obscure cu evoluție deosebit de gravă şi pericol major de insuficiență poliorganică. Astfel se impune restabilirea cît mai timpurie a funcțiilor intestinale la bolnavul operat. Scopul: studierea eficacității terapeutice a electromagnetobiorezonanței la bolnavii cu sindromul insuficienței intestinale postoperatorii. Material şi metode: Lotul de bază a inclus 39 bolnavi, bărbați -20, femei -19, cu vîrstă de la 18 până la 79 ani cu peritonite postoperatorii de diversă geneză. Lotul martor a fost format din 28 bolnavi cu peritonite fără aplicarea electromagneto-biorezonanței postoperatorii, similar după vîrstă şi sex. Intervenții chirurgicale sau efectuat pentru: apendicită destructivă – 12, ulcer gastro-duodenal perforat – 7, ileus aderențial intestinal acut – 5, colecistită acută calculoasă destructivă- 8, pancreonecroză- 7. Funcțiile motorie şi evacuatorie au fost monitorizate prin înregistrarea elecrtogastroenterogramei. Rezultate: În lotul de bază am consemnat o revigorare mai rapidă a funcțiilor motorii şi evacuării intestinale şi gastrice, comparativ cu lotul de control. Peristaltismul intestinal în lotul martor s-a apreciat în mediu peste 32±4 ore postoperatorii. La bolnavii lotului de bază acest termen a constituit în mediu 20,9±3 ore, diferență semnificativă. Am consemnat o anumită consecutivitate în restabilirea activității bioelectrice a tractului digestiv: inițial segmentul jejunal (a 3 zi postoperatorie ), apoi ileonul şi a stomacului (4-5 zi postoperatorii). Concluzii: Utilizarea electromagneto-biorezonanței în perioada postoperatorie la bolnavii cu patologie abdominală chirurgicală complicată cu peritonită accelerează procesele de restabilire a funcției motor-evacuatorii a tractului gastro-intestinal şi pot fi obiectivizate prin datele electrogastroenterografiei.Postoperative intestinal insufficiency represents one of the obscure complications, with the severe evolution, evolving serious danger of poliorganic insufficiency. This requires restoration of bowel function earlier at the operated patient. The aim: To study the therapeutic efficacy of the electromagnetic-biorezonance in patients with postoperative intestinal failure syndrome. Material and methods: Lot base including 39 patients, men -20, women-19 aged from 18 to 79 years with postoperative peritonitis of various geneses was studied. Control group consisted of 28 patients with peritonitis without applying electromagnetic- biorezonance postoperative therapy, similar by age and sex. Surgical interventions were performed for: destructive appendicitis - 12, peptic ulcer perforation - 7, acute intestinal ileus adhesive - 5, acute cholecystitis calculated destructive-8, pancreonecrosis-7. Motoric and evacuatoric functions were monitored by elecrtogastroenterogram recording. Results: In the base group we observed a faster revival of basic motoric function of intestinal and gastric evacuation, comparing with the control group. Peristaltics in the control group was appreciated on average over 32 ± 4 hours in the postoperative period. At patients from the based lot this time was on average 20.9 ± 3 hours, significant difference. We determined some consecutivety in restoring of bioelectrical activity of the digestive tract: initial jejunal segment (after three days postoperative), after ileum and stomach (4-5 days postoperative). Conclusions: Using the electromagnetic-biorezonance therapy in postoperative period at patients with abdominal surgical pathology, complicated by peritonitis accelerates the process of gastrointestinal tract motoric function restoring, and can be objectified by dates of electrogastroenterography

Screening strategies for the diagnosis of asymptomatic Leishmania infection in dialysis patients as a model for kidney transplant candidates

Despite being considered a tropical disease, visceral leishmaniasis (VL) caused by L. infantum is also endemic in the Mediterranean Europe and represents an increasing cause of morbidity and mortality in solid organ transplant (SOT) recipients. VL occurring in kidney transplant recipients is a severe event, often worsening the renal damage and leading to poor outcome. It is believed that most of VL cases in transplant recipients are caused by reactivation of a pre-existent, dormant leishmanial infection induced by the immunosuppressive drugs. Nevertheless, the prevalence of asymptomatic Leishmania infection in candidates to kidney transplant residing in or visiting endemic areas is unknown. As L. infantum is highly circulating in northeastern Italy, we aimed to examine the occurrence of this parasitic infection in 119 dialysis patients living in the mentioned area, 71 of whom were potential candidates to kidney transplant. By employing a combination of sensitive serological and molecular methods, we observed a prevalence of 15.9% asymptomatic Leishmania infection in the study cohort. This finding emphasizes the need of further evaluating potential screening strategies for Leishmania infection in solid organ transplant candidates residing in or visiting endemic areas

Developing Central Nervous System and Vulnerability to Platinum Compounds

Comparative studies on the effects of the platinum complexes in use or in clinical trials are carried out in order to discover differences in the neurotoxic potential and the reversibility of neurotoxicity. In this paper, we summarized the current literature on neurotoxicity and chemoresistance of cisplatin (cisPt) and discussed our recent efforts on the interference of cisPt and a new platinum compound [Pt(O,O′-acac)(γ-acac)(DMS)] (PtAcacDMS), with high specific reactivity with sulphur ligands instead of nucleobases as cisPt, on some crucial events of rat postnatal cerebellum development. The acute effects of drug treatments on cell proliferation and death in the external granular layer and granule cell migration and the late effects on the dendrite growth of Purkinje cells were evaluated. Together with the demonstrated antineoplastic effectiveness in vitro, compared with cisPt, data suggest a lower neurotoxicity of PtAcacDMS, in spite of its presence in the brain that involves considerations on the blood brain barrier permeability

Performance Assessment in Fingerprinting and Multi Component Quantitative NMR Analyses

An interlaboratory comparison (ILC) was organized with the aim to set up quality control indicators suitable for multicomponent quantitative analysis by nuclear magnetic resonance (NMR) spectroscopy. A total of 36 NMR data sets (corresponding to 1260 NMR spectra) were produced by 30 participants using 34 NMR spectrometers. The calibration line method was chosen for the quantification of a five-component model mixture. Results show that quantitative NMR is a robust quantification tool and that 26 out of 36 data sets resulted in statistically equivalent calibration lines for all considered NMR signals. The performance of each laboratory was assessed by means of a new performance index (named Qp-score) which is related to the difference between the experimental and the consensus values of the slope of the calibration lines. Laboratories endowed with a Qp-score falling within the suitable acceptability range are qualified to produce NMR spectra that can be considered statistically equivalent in terms of relative intensities of the signals. In addition, the specific response of nuclei to the experimental excitation/relaxation conditions was addressed by means of the parameter named NR. NR is related to the difference between the theoretical and the consensus slopes of the calibration lines and is specific for each signal produced by a well-defined set of acquisition parameters

Synthesis and characterization of UV-curable nanocellulose/ZnO/AlN acrylic flexible films: thermal, dynamic mechanical and piezoelectric response

This work is aimed at fabricating nanocomposites based on zinc oxide (ZnO) nanostructures and nanocellulose dispersed in a UV-cured acrylic matrix (EC) for application as functional coatings for self-powered applications. Morphological, thermal, and dynamic mechanical properties of the nanocomposites were characterized by X-Ray diffractometry (XRD), scanning electron microscopy, and differential scanning calorimetry. The piezoelectric behavior was evaluated in terms of root mean square (RMS) open circuit voltage, at different accelerations applied to cantilever beams. The generated voltage was correlated with ZnO nanostructures morphology, aluminum nitride film integration on the beam and proof mass insertion at the tip. Nitride layer increased the RMS voltage from 1 to 2.4 mV up to 3.9 mV (using ZnO nanoflowers). As confirmed by XRD analyses, the incorporation of ZnO nanostructures into the acrylic matrix favored an ordered structural arrangement of the deposited AlN layer, hence improving the piezoelectric response of the resulting nanocomposites. With proof mass insertion, the output voltage was further increased, reaching 4.5 mV for the AlN-coated system containing ZnO nanoflowers

In Silico Identification of a β2-Adrenoceptor Allosteric Site That Selectively Augments Canonical β2AR-Gs Signaling and Function

Activation of β2-adrenoceptors (β2ARs) causes airway smooth muscle (ASM) relaxation and bronchodilation, and β2AR agonists (β-agonists) are front-line treatments for asthma and other obstructive lung diseases. However, the therapeutic efficacy of β-agonists is limited by agonist-induced β2AR desensitization and noncanonical β2AR signaling involving β-arrestin that is shown to promote asthma pathophysiology. Accordingly, we undertook the identification of an allosteric site on β2AR that could modulate the activity of β-agonists to overcome these limitations. We employed the site identification by ligand competitive saturation (SILCS) computational method to comprehensively map the entire 3D structure of in silico-generated β2AR intermediate conformations and identified a putative allosteric binding site. Subsequent database screening using SILCS identified drug-like molecules with the potential to bind to the site. Experimental assays in HEK293 cells (expressing recombinant wild-type human β2AR) and human ASM cells (expressing endogenous β2AR) identified positive and negative allosteric modulators (PAMs and NAMs) of β2AR as assessed by regulation of β-agonist-stimulation of cyclic AMP generation. PAMs/NAMs had no effect on β-agonist-induced recruitment of β-arrestin to β2AR- or β-agonist-induced loss of cell surface expression in HEK293 cells expressing β2AR. Mutagenesis analysis of β2AR confirmed the SILCS identified site based on mutants of amino acids R131, Y219, and F282. Finally, functional studies revealed augmentation of β-agonist-induced relaxation of contracted human ASM cells and bronchodilation of contracted airways. These findings identify a allosteric binding site on the β2AR, whose activation selectively augments β-agonist-induced Gs signaling, and increases relaxation of ASM cells, the principal therapeutic effect of β-agonists