For a new class of algebras, called
EMV
-algebras, every idempotent element
a
determines an
MV
-algebra which is important for the structure of the
EMV
-algebra. Therefore, instead of standard ...homomorphisms of
EMV
-algebras, we introduce
EMV
-morphisms as a family of
MV
-homomorphisms from
MV
-algebras 0,
a
into other ones.
EMV
-morphisms enable us to study categories of
EMV
-algebras where objects are
EMV
-algebras and morphisms are special classes of
EMV
-morphisms. The category is closed under product. In addition, we define free
EMV
-algebras on a set
X
with respect to
EMV
-morphisms. If
X
is finite, then a free
EMV
-algebra on
X
is termwise equivalent to the free
MV
-algebra on
X
. For an infinite set
X
, the same is true introducing a so-called weakly free
EMV
-algebra.
There is an urgent need to develop new combination therapies beyond existing surgery, radio‐ and chemo‐therapy, perhaps initially combining chemotherapy with the targeting specificities of ...immunotherapy. For this, strategies to limit inflammation and immunosuppression and evasion in the tumour microenvironment are also needed. To devise effective new immunotherapies we must first understand tumour immunology, including the roles of T cells, macrophages, myeloid suppressor cells and of exosomes and microvesicles (EMVs) in promoting angiogenesis, tumour growth, drug resistance and metastasis. One promising cancer immunotherapy discussed uses cationic liposomes carrying tumour RNA (RNA‐lipoplexes) to provoke a strong anti‐viral‐like (cytotoxic CD8+) anti‐tumour immune response. Mesenchymal stem cell‐derived EMVs, with their capacity to migrate towards inflammatory areas including solid tumours, have also been used. As tumour EMVs clearly exacerbate the tumour microenvironment, another therapy option could involve EMV removal. Affinity‐based methods to deplete EMVs, including an immunodepletion, antibody‐based affinity substrate, are therefore considered. Finally EMV and exosome‐mimetic nanovesicles (NVs) delivery of siRNA or chemotherapeutic drugs that target tumours using peptide ligands for cognate receptors on the tumour cells are discussed. We also touch upon the reversal of drug efflux in EMVs from cancer cells which can sensitize cells to chemotherapy. The use of immunotherapy in combination with the advent of EMVs provides potent therapies to various cancers.
What's new?
This Mini‐Review brings together the field of exosomes and microvesicles (EMVs) as drug delivery vehicles together with the burgeoning area of cancer immunotherapy. We highlight the promise of cancer immunotherapies using exosomes and RNA lipoplexes as cancer vaccines, critically assess the promising but at times controversial results using Mesenchymal stem cell‐derived EMVs, discuss the possibility of therapeutic removal of EMVs and assess the use of EMVs and exosome‐mimetic nanovesicles (NVs) as drug delivery vehicles.
On EMV-algebras Dvurečenskij, Anatolij; Zahiri, Omid
Fuzzy sets and systems,
10/2019, Letnik:
373
Journal Article
Recenzirano
The paper deals with an algebraic extension of MV-algebras based on the definition of generalized Boolean algebras. We introduce a new class of structures, not necessarily with a top element, which ...are called EMV-algebras, in a way that every EMV-algebra contains an MV-algebra. First, we present basic properties of EMV-algebras. We give some examples, introduce and investigate congruence relations, ideals and filters on these algebras. We establish a basic representation result saying that each EMV-algebra can be embedded into an EMV-algebra with top element and we characterize EMV-algebras either as structures which are termwise equivalent to MV-algebras or as maximal ideals of EMV-algebras with top element. We study the lattice of ideals of an EMV-algebra and prove that every EMV-algebra has at least one maximal ideal. We define an EMV-clan of fuzzy sets as a special EMV-algebra where all operations are defined by points. We show that any semisimple EMV-algebra is isomorphic to an EMV-clan of fuzzy functions on a set. The set of EMV-algebras is neither a variety nor a quasivariety, but rather a special class of EMV-algebras which we call a q-variety of EMV-algebras. We present an equational base for each proper q-subvariety of the q-variety of EMV-algebras. We establish categorical equivalencies among the category of proper EMV-algebras, the category of MV-algebras with a fixed special maximal ideal, and a special category of Abelian unital ℓ-groups.
On EMV-algebras with square roots Dvurečenskij, Anatolij; Zahiri, Omid
Journal of mathematical analysis and applications,
08/2023, Letnik:
524, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A square root is a unary operation with some special properties. In the paper, we introduce and study square roots on EMV-algebras. First, the known properties of square roots defined on MV-algebras ...will be generalized for EMV-algebras, and we will also find some new ones for MV-algebras. We use square roots to characterize EMV-algebras. Then, we find a relation between the square root of an EMV-algebra and the square root of its representing EMV-algebra with top element. We show that each strict EMV-algebra has a top element, and we investigate the relation between divisible EMV-algebras and EMV-algebras with a special square root. Finally, we present square roots on tribes, EMV-tribes, and we present a complete characterization of any square root on an MV-algebra and an EMV-algebra by group addition in the corresponding unital ℓ-group.
This study investigates a novel heat transfer enhancement method named electromagnetic vibration (EMV) method. For the first time a stretched oscillator with geometries of string and strip was placed ...coaxially inside a heated copper tube and induced to vibrate at the natural frequencies. Longitudinal vibration of the stretched oscillators creates harsh turbulence, radial flow and vortexes inside the heated tube. Tests were conducted for various vibrational frequencies ranging 0 to 1 KHz in different mass flow rates. The experimental results indicated that oscillator with the geometry of strip has the better thermal performance; also the heat transfer coefficient can be increased with increasing vibration frequency from 2.18 to 2.50 folds. For comprehensive analyze at high frequency vibrations, a numerical model was conducted for the vibrating strip geometry to evaluate this new method capability in heat transfer performance enhancement. The numerical study shows that at 1 KHz frequency, heat transfer coefficient and thermal enhancement factor (TEF) can reach up to 32.2 and 14.2 fold compare to the plain tube, respectively. This magnificent increment shows the high potential of the EMV method as a new heat transfer augmentation technique.
•Vibrating oscillator inserted inside a heated tube for the first time.•A new electromagnetic vibration (EMV) method presented as an active method.•Thermal-frictional behaviors of the vibrating oscillator are studied.•The effect of changing the oscillator geometry and vibration frequency was discussed.
Previous studies indicate that the US equity market implied volatility index (VIX) impacts the crude oil market volatility. However, the VIX typically reflects macroeconomic fluctuations, little ...affected by social media or investor perception changes. In this paper, we use recently introduced news-based equity market volatility (EMV) trackers to examine their impacts on crude oil volatility in its various states and their ability to predict oil volatility relative to that of the VIX. Applying quantile regressions, the results indicate a significant impact of EMV trackers on the oil market volatility during periods of high oil volatility, whereas the impact is mostly insignificant when the oil market is less volatile, which points to an asymmetry. Further analysis shows that various EMV trackers (EMV-overall, EMV-commodity, EMV-crises) have better forecasting power than VIX, economic policy uncertainty (EPU) and geopolitical risk (GPR) indexes. Our findings are relevant to asset pricing, oil portfolio formation, and risk management.
•We explore the impact of news-based volatility trackers (EMV) on oil volatility.•The quantile regression model is employed.•The results are compared with VIX, EPU and GPR indexes.•EMV trackers have better forecasting power than other uncertainty indexes.
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•TCNQ molecules in (N-Xy-Qn)(TCNQ)2 salt are organized in tetramerized stacks.•Charge disproportionation in TCNQ stacks is observed (−0.83 e vs −0.33 e).•Tetramerization and EMV ...coupling complicates the vibrational spectra.•The room temperature conductivity equals 2.6 mS cm−1.
The (N-Xy-Qn)(TCNQ)2 anion-radical salt characterized by tetramerized stacks of the TCNQ acceptor molecules has been synthesized and characterized using vibrational spectroscopy and electrical resistivity measurements. The bond lengths analysis based on the crystal structure data, indicates that the TCNQ molecules are non-uniformly charged with −0.83 e localized on the inner B molecules and −0.33 e on the outer A molecules within ABBA tetramers. Both infrared and Raman spectra of (N-Xy-Qn)(TCNQ)2 are dominated by vibrational modes of TCNQ and display splitting related to the tetramerized structure. Many of these features are affected by the strong electron-molecular vibration (EMV) coupling. Other charge-sensitive modes allowed estimation of charge localized on TCNQ, with the results that confirm the charges estimated on basis of the crystal data. Electrical measurements revealed the low-conducting behavior with room temperature conductivity value of 2.6 mS cm−1 and temperature dependence of resistivity that can be explained within the band conduction model. The calculated activation energies range from 0.169 eV to 0.187 eV, depending on the crystallographic direction and thermal history of the sample.
To define, illustrate and to follow-up the diagnosis, pathophysiology and treatment of a subset of the known enhanced myometrial vascularity (EMV): its extreme form, associated with cesarean scar ...pregnancies (CSP) and with some cases pf placenta accreta spectrum being at increased risk of significant bleeding complications. We also aim to provide guidance to the management of such cases.
This is an IRB-approved retrospective observational study of thirteen patients with an extreme form of EMV complicating CSPs. Patient's age, parity, number of cesarean deliveries, initial and time to negative serum hCG levels, primary and secondary diagnoses, blood flow peak systolic velocities, primary and secondary treatments, uterine artery embolization and outcomes were recorded.
Gestational ages ranged 6-11 weeks at initial presentation. Initial serum hCG was 20.0-102.48 mIU/L (mean 44.4 mIU/L). Diameter of EMV reached 20-75 mm (mean 46.8 mm). The mean peak systolic velocity (PSV) was 84.2 cm/s (range 46.7-118.0). Primary treatments were: systemic methotrexate (MTX) alone; D&C alone; MTX and D local and systemic intra-gestational MTX injection; double cervical ripening balloon with systemic MTX; misoprostol and D emergent UAE. UAE and hysterectomy were the two main secondary treatments in 10 women except 1 having a D&C after UAE, and in 1 the lesion regressed without secondary treatment. Mean time to nonpregnant hCG levels was 21-122 days (mean 67.2). Mean follow-up was 110.2 days (range 26-160). Ten women were treated with UAE, 6 had one, 3 had two embolizations. Two women had hysterectomies, one of these for persistent bleeding. Based upon the common denominators of the clinical and the US pictures, our definition of extreme EMV is sustained form of EMV associated with treated or untreated CSP, with peak systolic velocities of blood flow over 50 cm/s, slow return or plateauing serum hCG, with or without clinically significant vaginal bleeding, unresponsive to initial or secondary treatment requiring uterine artery embolization or hysterectomy.
The EMV developing in the background of retained placental tissue associated with CSP differs following the normal regression of the physiologically re-modelled, dilated vascular bed from the faulty "disrepair" of the vessel wall in in treated or untreated CSPs. The "threatening" appearance of the above EMVs warranted the term "extreme", creating their separate new sub-category." Extreme forms of CSP-related EMV pose significant diagnostic and management challenges. Prompt recognition and intervention, the proactive use of UAE, can maximize the outcome of women affected by this "extreme" form of EMV enabling to preserve reproductive potential. Obstetricians, gynecologists and interventional radiologists should be aware of this form of severe vascular complication.
This study investigates the effect of infectious disease uncertainty on hotel room demand covering the period 2005–2020. Also, the extent to which the effect of uncertainty borne by infectious ...diseases varies across different hotels segments are examined. Furthermore, the latest infectious disease pandemic, COVID-19, was used to test the joint impact of state-imposed restrictions and infectious disease uncertainty on hotel room demand. Using Infectious Disease Equity Market Volatility (EMV-ID) tracker as a proxy for uncertainty, the findings showed that infectious disease uncertainty leads to a decline in state-level hotel occupancy both in the short- and long-run. These results rule out the potential confounding effect of state-level restrictions by demonstrating that EMV-ID accounts for additional variance in hotel demand. Findings also indicate that this negative effect is not uniform across hotel segments; the greater levels of state-imposed restrictions lead to decreases in hotel room demand. Practical and research implications are discussed.
•The impact infectious diseases induced uncertainty on U.S. hotel industry is examined.•Infectious disease equity market volatility tracker is used as the proxy of uncertainty.•Infectious disease induced uncertainty is negatively associated with hotel room demand in lagged terms.•The negative effect of infectious disease uncertainty is more profound on upscale hotels compared to economy hotels.•States with higher infectious disease-related restrictions experience a greater decline in room demand than states with fewer restrictions.
The magnetic turbulator and electromagnetic vibration (EMV) methods have recently been employed to enhance heat transfer in heat exchangers. This method involves placing a magnetic oscillator inside ...the tube and attaching a magnet with specific dimensions to this oscillator. Creating an AC magnetic field near the tube causes the magnet and the oscillator to vibrate, acting as a magnetic turbulator. In this study, multiple perforated magnetic turbulators were used inside the tube of a heat exchanger for the first time, and their impact on hydrothermal parameters was assessed. Various factors were examined, including perforation diameter, pitch, and fluid flow rate. The thermal enhancement factor (TEF) was used to identify the optimal configuration. The results showed that simple and perforated turbulators increased heat transfer up to 156% and 150%, respectively. However, the pressure drop in the presence of these turbulators was up to 1.97 and 1.86 times higher than that of a simple heat exchanger. In addition, the maximum value of TEF was observed in the presence of a perforated magnetic turbulators with a hole diameter of 2 mm and a hole pitch of 12 mm. This turbulator was the optimal choice, providing a TEF equivalent to 2.06.
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