183 research outputs found
Estimating the Yin-Yang Nature of Western Herbs: A Potential Tool Based on Antioxidation- Oxidation Theory
Background : One of the biggest obstacles to progress in traditional Chinese medicine (TCM) development in Western countries is the difficulty of applying the traditional concepts to the Western medicinal plants, which are not traditionally described in ancient literature. During recent years, new advances in the field of understanding Yin/Yang aspects from a modern bioscientific point of view have led to the conclusion that antioxidationoxidation concepts might mirror a Yin-Yang relationship.Methods: This study was intended to integrate the Yin-Yang theory of the traditional Chinese medicine with modern antioxidation-oxidation theory, and to propose a biochemical tool based on redox parameters (e.g. antioxidant capacity, chemiluminescence-CL signal inducing capacity), usable for the classification of Western medicinal plants from Yin/Yang perspective. Trolox equivalent antioxidant capacity (TEAC) of six vegetal aqueous extracts (Symphitum officinalae (radix)- SYM, Inula helenium (radix)- INU, Calendula officinalis (flores)- CAL, Angelica arhanghelica (folium)- ANG(F), Angelica arhanghelica (radix)- ANG(R), Ecbalium Elaterium (fruits)- ECB) and luminol-enhanced chemiluminescence of PMNL on addition of these vegetal extracts were measured. Percentages from the maximal or minimal values obtained were calculated for each extract (TEAC%, PMNL stimulation%, PMNL inhibition%, relative speed of action% (RSA%%)), specific Yin-Yang significance was assigned to each relative parameter. In the end, an integration of all the relative values was done, in order to find a global âYinâ or a âYangâ trait of each vegetal extract.Results: TEAC decreased in the following order: SYM > INU > CAL >ANG(F) > ANG(R > ECB. Three vegetal extracts (SYM > INU > ECB) decreased the luminol-enhanced chemiluminescence of PMNL, two (ANG(R) > ANG(F)) increased it, while one (CAL) had a dual effect. After the integration of the percentages, CAL was found to have a global âYangâ trait, while the rest of the plants had a global âYinâ trait.Conclusions: TEAC% and PMNL inhibition% appears to correlate with the Yin properties of herbs, while PMNL stimulation% and RSA% might correlate with Yang aspects within the formal TCM classification system, and may be useful criteria in describing the Western herbs from a TCM point of view.Key words: antioxidant, TEAC, herbs, chemiluminescence, Yin, Yang, TC
Dynamics of ripple formation on silicon surfaces by ultrashort laser pulses in sub-ablation conditions
An investigation of ultrashort pulsed laser induced surface modification due
to conditions that result in a superheated melted liquid layer and material
evaporation are considered. To describe the surface modification occurring
after cooling and resolidification of the melted layer and understand the
underlying physical fundamental mechanisms, a unified model is presented to
account for crater and subwavelength ripple formation based on a synergy of
electron excitation and capillary waves solidification. The proposed
theoretical framework aims to address the laser-material interaction in
sub-ablation conditions and thus minimal mass removal in combination with a
hydrodynamics-based scenario of the crater creation and ripple formation
following surface irradiation with single and multiple pulses, respectively.
The development of the periodic structures is attributed to the interference of
the incident wave with a surface plasmon wave. Details of the surface
morphology attained are elaborated as a function of the imposed conditions and
results are tested against experimental data
The role of endothelium in covid-19
The 2019 novel coronavirus, known as severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19), is causing a global pandemic. The virus primarily affects the upper and lower respiratory tracts and raises the risk of a variety of non-pulmonary consequences, the most severe and possibly fatal of which are cardiovascular problems. Data show that almost one-third of the patients with a moderate or severe form of COVID-19 had preexisting cardiovascular comorbidities such as diabetes mellitus, obesity, hypertension, heart failure, or coronary artery disease. SARS-CoV2 causes hyper inflammation, hypoxia, apoptosis, and a reninâangiotensin system imbalance in a variety of cell types, primarily endothelial cells. Profound endothelial dysfunction associated with COVID-19 can be the cause of impaired organ perfusion that may generate acute myocardial injury, renal failure, and a procoagulant state resulting in thromboembolic events. We discuss the most recent results on the involvement of endothelial dysfunction in the pathogenesis of COVID-19 in patients with cardiometabolic diseases in this review. We also provide insights on treatments that may reduce the severity of this viral infection
High shock release in ultrafast laser irradiated metals: Scenario for material ejection
We present one-dimensional numerical simulations describing the behavior of
solid matter exposed to subpicosecond near infrared pulsed laser radiation. We
point out to the role of strong isochoric heating as a mechanism for producing
highly non-equilibrium thermodynamic states. In the case of metals, the
conditions of material ejection from the surface are discussed in a
hydrodynamic context, allowing correlation of the thermodynamic features with
ablation mechanisms. A convenient synthetic representation of the thermodynamic
processes is presented, emphasizing different competitive pathways of material
ejection. Based on the study of the relaxation and cooling processes which
constrain the system to follow original thermodynamic paths, we establish that
the metal surface can exhibit several kinds of phase evolution which can result
in phase explosion or fragmentation. An estimation of the amount of material
exceeding the specific energy required for melting is reported for copper and
aluminum and a theoretical value of the limit-size of the recast material after
ultrashort laser irradiation is determined. Ablation by mechanical
fragmentation is also analysed and compared to experimental data for aluminum
subjected to high tensile pressures and ultrafast loading rates. Spallation is
expected to occur at the rear surface of the aluminum foils and a comparison
with simulation results can determine a spall strength value related to high
strain rates
Spin Factor in Path Integral Representation for Dirac Propagator in External Fields
We study the spin factor problem both in and dimensions which are
essentially different for spin factor construction. Doing all Grassmann
integrations in the corresponding path integral representations for Dirac
propagator we get representations with spin factor in arbitrary external field.
Thus, the propagator appears to be presented by means of bosonic path integral
only. In dimensions we present a simple derivation of spin factor
avoiding some unnecessary steps in the original brief letter (Gitman,
Shvartsman, Phys. Lett. {\bf B318} (1993) 122) which themselves need some
additional justification. In this way the meaning of the surprising possibility
of complete integration over Grassmann variables gets clear. In
dimensions the derivation of the spin factor is completely original. Then we
use the representations with spin factor for calculations of the propagator in
some configurations of external fields. Namely, in constant uniform
electromagnetic field and in its combination with a plane wave field.Comment: 34 pages, LaTe
The more the better: on the formation of single-phase high entropy alloy nanoparticles as catalysts for the oxygen reduction reaction.
High entropy alloys (HEAs) are an important new material class with significant application potential in catalysis and electrocatalysis. The entropy-driven formation of HEA materials requires high temperatures and controlled cooling rates. However, catalysts in general also require highly dispersed materials, i.e., nanoparticles. Only then a favorable utilization of the expensive raw materials can be achieved. Several recently reported HEA nanoparticle synthesis strategies, therefore, avoid the high-temperature regime to prevent particle growth. In our work, we investigate a system of five noble metal single-source precursors with superior catalytic activity for the oxygen reduction reaction. Combining in situ X-ray powder diffraction with multi-edge X-ray absorption spectroscopy, we address the fundamental question of how single-phase HEA nanoparticles can form at low temperatures. It is demonstrated that the formation of HEA nanoparticles is governed by stochastic principles and the inhibition of precursor mobility during the formation process favors the formation of a single phase. The proposed formation principle is supported by simulations of the nanoparticle formation in a randomized process, rationalizing the experimentally found differences between two-element and multi-element metal precursor mixtures
280 one-opposition near-Earth asteroids recovered by the EURONEAR with the <i>Isaac Newton</i> Telescope
Context. One-opposition near-Earth asteroids (NEAs) are growing in number, and they must be recovered to prevent loss and mismatch risk, and to improve their orbits, as they are likely to be too faint for detection in shallow surveys at future apparitions.
Aims. We aimed to recover more than half of the one-opposition NEAs recommended for observations by the Minor Planet Center (MPC) using the Isaac Newton Telescope (INT) in soft-override mode and some fractions of available D-nights. During about 130 h in total between 2013 and 2016, we targeted 368 NEAs, among which 56 potentially hazardous asteroids (PHAs), observing 437 INT Wide Field Camera (WFC) fields and recovering 280 NEAs (76% of all targets).
Methods. Engaging a core team of about ten students and amateurs, we used the THELI, Astrometrica, and the Find_Orb software to identify all moving objects using the blink and track-and-stack method for the faintest targets and plotting the positional uncertainty ellipse from NEODyS.
Results. Most targets and recovered objects had apparent magnitudes centered around V ~ 22.8 mag, with some becoming as faint as V ~ 24 mag. One hundred and three objects (representing 28% of all targets) were recovered by EURONEAR alone by Aug. 2017. Orbital arcs were prolonged typically from a few weeks to a few years; our oldest recoveries reach 16 years. The OâC residuals for our 1854 NEA astrometric positions show that most measurements cluster closely around the origin. In addition to the recovered NEAs, 22â000 positions of about 3500 known minor planets and another 10â000 observations of about 1500 unknown objects (mostly main-belt objects) were promptly reported to the MPC by our team. Four new NEAs were discovered serendipitously in the analyzed fields and were promptly secured with the INT and other telescopes, while two more NEAs were lost due to extremely fast motion and lack of rapid follow-up time. They increase the counting to nine NEAs discovered by the EURONEAR in 2014 and 2015.
Conclusions. Targeted projects to recover one-opposition NEAs are efficient in override access, especially using at least two-meter class and preferably larger field telescopes located in good sites, which appear even more efficient than the existing surveys
Death by SARS-CoV 2: a Romanian COVID-19 multi-centre comorbidity study
Evidence regarding the relation between SARS-CoV-2 mortality and the underlying medical condition is scarce. We conducted an observational, retrospective study based on Romanian official data about location, age, gender and comorbidities for COVID-19 fatalities. Our findings indicate that males, hypertension, diabetes, obesity and chronic kidney disease were most frequent in the COVID-19 fatalities, that the burden of disease was low, and that the prognosis for 1-year survival probability was high in the sample. Evidence shows that age-dependent pairs of comorbidities could be a negative prognosis factor for the severity of disease for the SARS-CoV 2 infection
Reconstructia sanului dupa diferitele proceduri chirurgicale adresate cancerului mamar
Spitalul Clinic de UrgenĆŁÄ âBagdasar-Arseniâ BucureĆti, RomĂąnia, Spitalul Clinic de urgenĆŁÄ âSf. Pantelimonâ BucureĆti, RomĂąnia, Spitalul JudeĆŁean de UrgenĆŁÄ PiteĆti, RomĂąnia, Al XI-lea Congres al AsociaÈiei Chirurgilor âNicolae Anestiadiâ din Republica Moldova Èi cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova âIacomi-RÄzeÈuâ 27-30 septembrie 2011Introducere. Dintre neoplaziile intalnite la femeie, cancerul mamar o reprezinta pe cea mai frecventa incidenta acestuia fiind in crestere in ultimele
decenii. Chirurgia de conservare a sanului este acum larg acceptata drept tratamentul de electie in cancerul mamar.Actualmente, cancerul mamar
este abordat in echipe pluridisciplinare, reconstructia dupa diferitele tipuri de interventii de exereza fiind preferata in majoritatea cazurilor. Se are in vedere reconstructia volumului sanului, simetrizarea sanului nou format cu cel controlateral si reconstructia placii areolo-mamare. Material si metoda.
Lucrarea de fata are la baza studiul retrospectiv al unui numar de 7 cazuri de cancer mamar tratate in Spitalul Clinic de Urgenta âBagdasar-Arseniâ in
intervalul Iunie 2008 â Iunie 2011. Au fost luate in calcul atat cazurile la care s-au facut in cadrul aceleasi interventii chirurgicale, cat si cazurile la care
reconstructia s-a facut la un anumit interval distanta.Rezultate. Rezultatele au fost bune in cadrul ambelor tehnici â reconstructie imediata dupa ablatie
si reconstructie la distanta â insa procentul complicatiilor asociate a fost mai mare pentru reconstructia la distanta, in mare masura datorita remanierilor tisulare aparute intre cele doua interventii chirurgicale. Mortalitatea a fost 0, iar in cadrul morbiditatii am intalnit un caz cu necroza parcelara
ce a necesitat o reinterventie pentru grefare si un caz de limforagie persistenta, care odata devenit cronic, a necesitat indepartarea protezei de silicon.
Concluzii.-Tehnica de reconstructie este una dificila si minutioasa, al carui rezultat favorabil este dependent atat de alegerea unei tehnici de ablatie
potrivita urmata de una de reconstructie individuala cat si de colaborarea interdisciplinara intre chirurgul de chirurgie generala, chirurgul plastician
si medicul oncolog- In urma cazurilor prezentate si a rezultatelor foarte bune obtinute optam pentru reconstructia imediata urmata de tratamentul
chimioterapeutic specific.-Din experienta noastra consideram extrem de importante indicatia chirurgicala, tehnica pentru care se opteaza, acordul
asupra abordului utilizat al membrilor echipei pluridisciplinare si urmarirea postoperatorie atenta
Predictors for pregnancy outcomes in Romanian women with Type 1 Diabetes Mellitus: a prospective study
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