846 research outputs found
Consideration of Reaction Forces of Holonomic Constraints as Generalized Coordinates in Approximate Determination of Lower Frequencies of Elastic Systems
A new method for determination of lower frequencies of mechanical systems consisting of elastic bodies connected to each other is offered. The conditions of connection of bodies are written as holonomic constraints, the reactions of which are considered as generalized coordinates. Therefore the number of degrees of freedom proves to be equal to the number of constraints
Microstructural and morphological properties of homoepitaxial (001)ZnTe layers investigated by x-ray diffuse scattering
The microstructural and morphological properties of homoepitaxial (001)ZnTe
layers are investigated by x-ray diffuse scattering. High resolution reciprocal
space maps recorded close to the ZnTe (004) Bragg peak show different diffuse
scattering features. One kind of cross-shaped diffuse scattering streaks along
directions can be attributed to stacking faults within the epilayers.
Another kind of cross-shaped streaks inclined at an angle of about 80deg with
respect to the in-plane direction arises from the morphology of the
epilayers. (abridged version
Pelvic floor function after third and fourth degree perineal lacerations: a case-control study on quality of life
Background: The primary aim of this study was to compare the quality of life between women with obstetric anal sphincter injury (OASI) and women with intact perineum or minor vaginal tears following their first vaginal birth through a validated urogynaecological questionnaire. As a secondary aim, we wanted to identify the specific symptoms for pelvic floor dysfunction after a vaginal birth. Methods: One hundred thirty-three cases (III- and IV-degree vaginal tears) and 133 controls (intact perineum or I- and II-degree vaginal tear) were asked to fill the PFDI-20 condition-specific and quality of life survey at three and 12 months after vaginal delivery. The survey evaluates pelvic floor dysfunction symptoms through three subsections: the Pelvic Organ Prolapse Distress Inventory (POPDI), the Colorectal-Anal Distress Inventory (CRADI), and Urinary Distress Inventory, (UDI). The scoring system ranges from 0 (no distress) to 100 (maximum distress) for each subsection, subsequently summed up to obtain the summary score (0 to 300). The patients recruited were asked to complete the survey at 3- and 12-months follow-up visit. Accordingly, data collection started. Categorical variables were subjected to Chi-square test or Fisher’s Exact test. Quantitative variables were compared through Student’s t-test or Mann-Whitney test. Results: All surveys have shown statistically significant differences when comparing the cases to the control group. Consequently, PFDI-20 has shown a strong correlation between III- and IV-grade lacerations and pelvic floor dysfunction persistence at 12 months after delivery. Intestinal symptoms were the most reported disturbances among women with previous OASI. Conclusions: Major vaginal tears have demonstrated to have a strong impact on women’s quality of life up to a follow-up of 12 months. The use of PFDI-20 questionnaire is a useful and valid tool in the diagnosis and follow-up of genital prolapse, fecal and urinary incontinence in primiparous women with a history of OASI. Thus, its application in clinical practice can help offering the most adequate rehabilitative treatment
Generation of cytocompatible superhydrophobic Zr–Cu–Ag metallic glass coatings with antifouling properties for medical textiles
Zirconium–Copper-based metallic glass thin films represent promising coatings in the biomedical sector for their combination of antibacterial property and wear resistance. However, finding a Zr–Cu metallic glass composition with desirable cytocompatibility and antibacterial property is extremely challenging. In this work, we have created a cytocompatible and (super-)hydrophobic Zr–Cu–Ag metallic glass coating with ≈95% antifouling properties. First, a range of different chemical compositions were prepared via Physical Vapor Deposition magnetron by co-sputtering Zr, Cu, and Ag onto a Polybutylene terephthalate (PBT) substrate among which Zr93·5Cu6·2Ag0.2, Zr76·7Cu22·7Ag0.5, and Zr69·3Cu30·1Ag0.6 were selected to be further investigate for their surface properties, antibacterial activity, and cytocompatibility. Scanning electron microscopy (SEM) images revealed a micro-roughness fibrous structure holding superhydrophobic properties demonstrated by specimens' static and dynamic contact angle measurements ranging from 130° to 150°. The dynamic contact angle measurements have shown hysteresis below 10° for all coated samples which indicated the superhydrophobicity of the samples. To distinguish between antifouling and bactericidal effect of the coating, ions release from coatings into Luria Bertani Broth (LB), and Dulbecco's Modified Eagle Medium (DMEM) solutions were evaluated by inductively coupled plasma mass spectrometry (ICP-MS) measurements after 24 ​h and 5 days. Antifouling properties were evaluated by infecting the specimens' surface with the Gram-positive Staphylococcus aureus and the Gram-negative Escherichia coli strain reporting a ≈95% reduction of bacteria adhesion as visually confirmed by FESEM and fluorescent live/dead staining. Human mesenchymal stem cells (hMSC) were used for direct cytocompatibility evaluation of coated samples and their metabolic activity was evaluated via relative fluorescence unit after 24 ​h and 5 days confirming that it was comparable to the controls (>97% viable cells). The results were further visualized by FESEM, fluorescent staining by Live/Dead Viability/Cytotoxicity Kit and confirmed the cytocompatibility of all coated samples. Finally, hMSC′ cytoplasm was stained by May Grunwald and Giemsa after 5days to detect and visualize the released ions which have diffused through the cells' membrane
New tools in percutaneous minimally invasive chronic subdural hematomas evacuation
Background: Incidence of chronic subdural hematomas (cSDH) is expected to progressive rise in the next decades. There is no univocal indication of the approach to be used. Furthermore, there is no data about the efficacy of twist drill craniostomy (TDC) in hematomas with membranes. Objective: To describe our modified technique for TDC in patients affected by cSDH with membranes and in treatment with antiplatelets. Methods: We analyzed a group of 37 patients, affected by cSDH with membrane (type D laminar membrane and type G trabecular membrane according to Nakaguchi classification), treated with mushroom TDC using a modified technique. Results: After surgery the average maximum thickness of the common postoperative liquoral subdural collection decreased from 18.8 to 6.21 mm. We documented one acute subdural hematoma (2.7%), asymptomatic and not treated, and one recurrence of cSDH (2.7%) after 2 months that needed re-intervention with single burr hole. Conclusions: We presented a modified twist drill technique, characterized by the introduction of an application of a new device that optimizes both surgical results, clinical outcome and surgical procedure time. The presence of membrane type D and G does not affect the efficacy of drainage, that is negatively related to the presence of clots or acute hematoma. This modified technique is safe, fast, effective and represents a valid first line treatment of an unstable and unpredictable pathology such as cSDH. We suggest performing such technique on a larger patients’ cohort to further validate its effectiveness
INFLAMMATORY BOWEL DISEASE: AN UPDATE OVERVIEW ON THE HEAT SHOCK PROTEIN INVOLVEMENT
Abstract: Inflammatory bowel diseases (IBDs) represent chronic idiopathic disorders, including
Crohn’s disease (CD) and ulcerative colitis (UC), in which one of the trigger factors is represented
by aberrant immune interactions between the intestinal epithelium and the intestinal microbiota.
The involvement of heat shock proteins (HSPs) as etiological and pathogenetic factors is becoming
of increasing interest. HSPs were found to be differentially expressed in the intestinal tissues and
sera of patients with CD and UC. It has been shown that HSPs can play a dual role in the disease,
depending on the stage of progression. They can support the inflammatory and fibrosis process, but
they can also act as protective factors during disease progression or before the onset of one of the
worst complications of IBD, colorectal cancer. Furthermore, HSPs are able to mediate the interaction
between the intestinal microbiota and intestinal epithelial cells. In this work, we discuss the involve ment of HSPs in IBD considering their genetic, epigenetic, immune and molecular roles, referring
to the most recent works present in the literature. With our review, we want to shed light on the
importance of further exploring the role of HSPs, or even better, the role of the molecular chaperone
system (CS), in IBD: various molecules of the CS including HSPs may have diagnostic, prognostic
and therapeutic potential, promoting the creation of new drugs that could overcome the side-effects
of the therapies currently used
Ejection fraction and mortality: A nationwide register-based cohort study of 499 153 women and men
Aims: We investigated the sex-based risk of mortality across the spectrum of left ventricular ejection fraction (LVEF) in a large cohort of patients in Australia.
Methods and results: Quantified levels of LVEF from 237 046 women (48.1%) and 256 109 men undergoing first-time, routine echocardiography (2000–2019) were linked to 119 232 deaths (median 5.6 years of follow-up). Overall, 17.6% of men vs. 8.3% of women had an LVEF P\u3c 0.001] in women and 1.21 (95% CI 1.05–1.39; P = 0.008) in men. In women, an LVEF of 60.0–64.9% was also associated with a HR 1.33 (95% CI 1.16–1.52; P\u3c 0.001) for cardiovascular-related mortality. These associations were most striking in women and men aged
Conclusions: Among patients investigated for suspected or established cardiovascular disease, we found clinically relevant sex-based differences in the distribution and mortality associated with an LVE
Tragacanth gum as green binder for sustainable water-processable electrochemical capacitor
9Enabling green fabrication processes for energy storage devices is becoming a key aspect in order to achieve a sustainable fabrication cycle. Here we focus on the exploitation of the tragacanth gum, an exudated gum like arabic and karaya gums, as green binder for the preparation of carbon-based for electrochemical capacitors. The electrochemical performance of tragacanth (TRGC)-based electrodes are thoroughly investigated and compared with another water-soluble binder largely used in this field, i.e. sodium-carboxymethyl cellulose (CMC). Apart from the higher sustainability both in production and processing, TRGC exhibits a lower impact on the obstruction of pores in the final active material film with respect to CMC, allowing for more available surface area. This directly impacts on the electrochemical performances resulting in a higher specific capacitance and better rate capability. Moreover, the TRGC-based supercapacitor shows a superior thermal stability than CMC with a capacity retention of about 80 % after 10.000 cycles at 70 °C.partially_openopenScalia, Alberto; Zaccagnini, Pietro; Armandi, Marco; Latini, Giulio; Versaci, Daniele; Lanzio, Vittorino; Varzi, Alberto; Passerini, Stefano; Lamberti, AndreaScalia, Alberto; Zaccagnini, Pietro; Armandi, Marco; Latini, Giulio; Versaci, Daniele; Lanzio, Vittorino; Varzi, Alberto; Passerini, Stefano; Lamberti, Andre
Current fluctuations in a single tunnel junction
We study noise spectra of currents through a tunnel junction in weak
tunneling limit. We introduce effective capacitance to take into account the
interaction effect and explicitly incorporate the electromagnetic environment
of the junction into the formulation. We study the effect of charging energy
and macroscopic environment on noise spectra. We calculate current fluctuations
at tunneling barrier and fluctuations measured at leads. It is shown that two
fluctuations have different noise spectra and the relation between them is
nontrivial. We provide an explanation for the origin of the difference.
Experimental implications are discussed.Comment: 25 pages, Revtex 3.
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