168 research outputs found

    Noninvasive patch resonator-based measurements on cultural heritage materials

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    In this work, a noninvasive microwave-based system for monitoring water content in stone materials used in Cultural Heritage structures is presented. By placing a planar resonator in contact with the considered stone sample, through reflection scattering parameter measurements, it is possible to associate the resonant frequency of the resonator to the moisture content of the stone sample. In this way, an experimental relationship between resonant frequency and moisture content can be obtained. Experimental tests are carried out on two types of materials, namely gentile and carparo stones: which are typically found in Cultural Heritage structures in Southern Italy and they are particularly affected by deterioration and decay phenomena. Measurements were performed for five levels of water content of the stone samples, and the empirical relationship between each considered level of water content and the corresponding measured quantity were derived. The obtained results demonstrate that this solution appears robust

    Coronary Artery By-Pass Grafting in Patient With Paroxysmal Nocturnal Hemoglobinuria (Case Report)

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    Paroxysmal nocturnal haemoglobinuria (PNH) is a clonal haematopoietic stem cell disease that presents with haemolytic anaemia, thrombosis and bone marrow failure. We report a case of a 51-year-old male with a history of PNH in treatment with Eculizumab admitted to our Hospital for acute chest pain and dyspnoea. The diagnosis was a triple vessel disease and patient was scheduled for coronary artery bypass grafting surgery. To balance the risk between thrombosis and bleeding in this particular clinical setting, we decided to use thromboelastography (TEG) as point of care solution and we used the R parameter as the target of our anticoagulant therapy. The R parameter between 11 and 14 sec can be used as a target value to balance the risk; in addition, there was no evidence of acute hemolysis during the surgery and supplemental dose of Eculizumab was administered in order to minimize any potential exacerbation of intravascular hemolysis

    Аортокоронарное шунтирование у пациента с пароксизмальной ночной гемоглобинурией (клиническое наблюдение)

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    Paroxysmal nocturnal haemoglobinuria (PNH) is a clonal haematopoietic stem cell disease that presents with haemolytic anaemia, thrombosis and bone marrow failure. We report a case of a 51-year-old male with a history of PNH in treatment with Eculizumab admitted to our Hospital for acute chest pain and dyspnoea. The diagnosis was a triple vessel disease and patient was scheduled for coronary artery bypass grafting surgery. To balance the risk between thrombosis and bleeding in this particular clinical setting, we decided to use thromboelastography (TEG) as point of care solution and we used the R parameter as the target of our anticoagulant therapy. The R parameter between 11 and 14 sec can be used as a target value to balance the risk; in addition, there was no evidence of acute hemolysis during the surgery and supplemental dose of Eculizumab was administered in order to minimize any potential exacerbation of intravascular hemolysis.Пароксизмальная ночная гемоглобинурия (ПНГ) — клональное заболевание гемопоэтических стволовых клеток, которое проявляется гемолитической анемией, тромбозами и недостаточностью функции костного мозга. Пациент мужского пола 51 года с ПНГ в анамнезе, по поводу которой он получал лечение экулизумабом, поступил в больницу с жалобами на острую боль в грудной клетке и одышку. Поставили диагноз трехсосудистого поражения коронарного русла, по поводу чего запланировали проведение аортокоронарного шунтирования. Для того, чтобы избежать развития как тромбоза, так и кровотечения, в данном сложном клиническом случае, решили провести пациенту тромбоэластографическое исследование и использовать параметр R в качестве целевого при проведении антикоагулянтной терапии. При поддержании значений данного параметра в рамках 11-14 сек можно достичь оптимального баланса между риском тромбоза и кровотечения. Кроме того, во время оперативного вмешательства не наблюдали острого гемолиза, а для уменьшения риска развития внутрисосудистого гемолиза дополнительно назначили экулизумаб

    Measurement results and improvements on an open EPR system

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    Electron spin resonance (ESR) is a spectroscopic method that allows to measure stable radicals induced by ionizing radiation. The EPR measurements can help to estimate the dose absorbed by people exposed during a nuclear disaster, detecting the number of radicals induced in their mobile phones due to the exposition [1]. Using conventional closed microwave cavities, the phone display must be fragmented in order to be introduced inside the resonator, becoming no more usable. The aim of this work is to develop a system, compatible with the spectrometer Bruker Elexys E500, able to preserve the sample integrity. The system uses an X-band resonant metallic cavity with a slit, realized on one side, for the leak of the excitation magnetic field and a Helmotz coil pair. The resonator allows measuring a sample lodged outside the cavity, while the coils produce a 100 kHz modulated field that encodes the output signal at a particular frequency and increases the SNR

    Organometallic iridium(III) anticancer complexes with new mechanisms of action: NCI-60 screening, mitochondrial targeting, and apoptosis

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    Platinum complexes related to cisplatin, cis-[PtCl2(NH3)2], are successful anticancer drugs; however, other transition metal complexes offer potential for combating cisplatin resistance, decreasing side effects, and widening the spectrum of activity. Organometallic half-sandwich iridium (IrIII) complexes [Ir(Cpx)(XY)Cl]+/0 (Cpx = biphenyltetramethylcyclopentadienyl and XY = phenanthroline (1), bipyridine (2), or phenylpyridine (3)) all hydrolyze rapidly, forming monofunctional G adducts on DNA with additional intercalation of the phenyl substituents on the Cpx ring. In comparison, highly potent complex 4 (Cpx = phenyltetramethylcyclopentadienyl and XY = N,N-dimethylphenylazopyridine) does not hydrolyze. All show higher potency toward A2780 human ovarian cancer cells compared to cisplatin, with 1, 3, and 4 also demonstrating higher potency in the National Cancer Institute (NCI) NCI-60 cell-line screen. Use of the NCI COMPARE algorithm (which predicts mechanisms of action (MoAs) for emerging anticancer compounds by correlating NCI-60 patterns of sensitivity) shows that the MoA of these IrIII complexes has no correlation to cisplatin (or oxaliplatin), with 3 and 4 emerging as particularly novel compounds. Those findings by COMPARE were experimentally probed by transmission electron microscopy (TEM) of A2780 cells exposed to 1, showing mitochondrial swelling and activation of apoptosis after 24 h. Significant changes in mitochondrial membrane polarization were detected by flow cytometry, and the potency of the complexes was enhanced ca. 5× by co-administration with a low concentration (5 μM) of the γ-glutamyl cysteine synthetase inhibitor L-buthionine sulfoximine (L-BSO). These studies reveal potential polypharmacology of organometallic IrIII complexes, with MoA and cell selectivity governed by structural changes in the chelating ligands

    Asiatic Acid Inhibits Liver Fibrosis by Blocking TGF-beta/Smad Signaling In Vivo and In Vitro

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    Liver fibrosis is a major cause of liver failure, but treatment remains ineffective. In the present study, we investigated the mechanisms and anti-hepatofibrotic activities of asiatic acid (AA) in a rat model of liver fibrosis induced by carbon tetrachloride (CCl4) and in vitro in TGF-beta1-stimulated rat hepatic stellate cell line (HSC-T6). Treatment with AA significantly attenuated CCl4-induced liver fibrosis and functional impairment in a dosage-dependent manner, including blockade of the activation of HSC as determined by inhibiting de novo alpha smooth muscle actin (a-SMA) and collagen matrix expression, and an increase in ALT and AST (all p<0.01). The hepatoprotective effects of AA on fibrosis were associated with upregulation of hepatic Smad7, an inhibitor of TGF-beta signaling, thereby blocking upregulation of TGF-beta1 and CTGF and the activation of TGF-beta/Smad signaling. The anti-fibrosis activity and mechanisms of AA were further detected in vitro in HSC-T6. Addition of AA significantly induced Smad7 expression by HSC-T6 cells, thereby inhibiting TGF-beta1-induced Smad2/3 activation, myofibroblast transformation, and collagen matrix expression in a dosage-dependent manner. In contrast, knockdown of Smad7 in HSC-T6 cells prevented AA-induced inhibition of HSC-T6 cell activation and fibrosis in response to TGF-beta1, revealing an essential role for Smad7 in AA-induced anti-fibrotic activities during liver fibrosis in vivo and in vitro. In conclusion, AA may be a novel therapeutic agent for liver fibrosis. Induction of Smad7-dependent inhibition of TGF-beta/Smad-mediated fibrogenesis may be a central mechanism by which AA protects liver from injury
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