111 research outputs found

    Inferring phase transitions and critical exponents from limited observations with Thermodynamic Maps

    Full text link
    Phase transitions are ubiquitous across life, yet hard to quantify and describe accurately. In this work, we develop an approach for characterizing generic attributes of phase transitions from very limited observations made deep within different phases' domains of stability. Our approach is called Thermodynamic Maps, which combines statistical mechanics and molecular simulations with score-based generative models. Thermodynamic Maps enable learning the temperature dependence of arbitrary thermodynamic observables across a wide range of temperatures. We show its usefulness by calculating phase transition attributes such as melting temperature, temperature-dependent heat capacities, and critical exponents. For instance, we demonstrate the ability of thermodynamic maps to infer the ferromagnetic phase transition of the Ising model, including temperature-dependent heat capacity and critical exponents, despite never having seen samples from the transition region. In addition, we efficiently characterize the temperature-dependent conformational ensemble and compute melting curves of the two RNA systems GCAA tetraloop and HIV-TAR, which are notoriously hard to sample due to glassy-like landscapes

    Comparative study of bupivacaine alone and bupivacaine along with buprenorphine in axillary brachial plexus block: a prospective, randomized, single blind study

    Get PDF
    Background: Different additives have been used to prolong brachial plexus block. We performed a prospective, randomized single-blind study to compare Bupivacaine alone and Bupivacaine along with Buprenorphine for onset, quality, and duration of block as well as post-operative analgesia and any complication in axillary brachial- plexus block.Methods: Randomized controlled study was carried out among 60 patients of either sex, aged 20-60 years. ASA grade I or II undergoing elective hand, forearm, elbow surgery under axillary brachial plexus block. Patients were randomly divided into two groups.Group-l received 30 ml of 0.35% Bupivacaine alone in axillary block.Group-II received 30 ml of 0.35% Bupivacaine with 3µg/kg Buprenorphine in axillary block. Time taken for onset and completion of motor and sensory block as well as complete duration of block were noted in both groups. Any complication during procedure, during surgery as well as post-operatively were noted and treated.Results: Addition of Buprenorphine (3µg/kg) to Bupivacaine mixture in peripheral nerve block did not affected the onset time for motor as well as sensory block. Mean duration of motor block was 284.33±78.94 mins. in group I and in group II 307.33±60.26 mins. Mean duration of sensory block 305.066±83.64 mins. in group I while 580.166±111.45 mins. in group II. It suggests duration of sensory block was prolonged in group II then group I.Conclusions: Addition of Buprenorphine to local anesthetic drug provides good post-operative analgesia. Buprenorphine significantly prolongs sensory block and lengthens duration of analgesia without prolonging duration of motor block

    Herbal used as Epigenetic for Cancer Treatment

    Get PDF
    Patterns of chromatin accessibility, which are in turn altered by epigenetic mechanisms, are responsible for determining the interactions that take place between transcription machinery, genes, and the cis-regulatory elements of those genes. Mutations that interfere with epigenetic processes frequently have the unfortunate side effect of causing cancer. Since these mutations can be undone, numerous anticancer treatments that target epigenetic pathways are now being developed and evaluated. (Cancer) is becoming more and more common everywhere. This decline in clinical outcomes is a result of a number of factors, including late diagnosis, a lack of efficient treatments for particular cancer subtypes, and drug resistance. Treatment resistance and stemness traits have been recognised as markers of this disease, and it has been demonstrated that epigenetic changes play a role in the process of cancer growth. Understanding these alterations and how they impact cancer carcinogenesis treatment is challenging but crucial. However, it may be able to provide the special knowledge needed to use these alterations as potential diagnostic, prognostic, therapeutic agents, and predictors of treatment efficacy. This underlines the importance of continued research to advance our knowledge of cancer carcinogenesis and epigenetics and help us overcome these challenges. This review aims to provide an overview of the state of the art in epigenetics research for cancer detection and treatment and to stimulate discussion on this subject

    Phase transitions in a network with range dependent connection probability

    Full text link
    We consider a one-dimensional network in which the nodes at Euclidean distance ll can have long range connections with a probabilty P(l)∼l−δP(l) \sim l^{-\delta} in addition to nearest neighbour connections. This system has been shown to exhibit small world behaviour for δ<2\delta < 2 above which its behaviour is like a regular lattice. From the study of the clustering coefficients, we show that there is a transition to a random network at δ=1\delta = 1. The finite size scaling analysis of the clustering coefficients obtained from numerical simulations indicate that a continuous phase transition occurs at this point. Using these results, we find that the two transitions occurring in this network can be detected in any dimension by the behaviour of a single quantity, the average bond length. The phase transitions in all dimensions are non-trivial in nature.Comment: 4 pages, revtex4, submitted to Physical Review

    Exchange bias in La0.7Sr0.3CrO3/La0.7Sr0.3MnO3/La0.7Sr0.3CrO3 heterostructures

    Get PDF
    In the recent past, heterostructures of magnetic oxide thin films have attracted a great deal of research excitement due to very interesting physical properties such as antiferromagnetic interlayer coupling, tunable exchange-bias, interfacial driven magnetic properties and high mobility electron gas across the interfaces. In this work, we report on the comprehensive magnetic properties observed from the heterostructures of (2 unit cells) La0.7Sr0.3CrO3/(8 unit cells) La0.7Sr0.3MnO3/(2 unit cells) La0.7Sr0.3CrO3, which are epitaxially deposited on SrTiO3 substrate by plasma-assisted oxide molecular beam epitaxy. Using SQUID magnetometer, the magnetic properties are studied when the magnetic field was applied both in plane and out of plane. The Curie temperature of this structure is found to be at 290 K. Most significantly, at 2 K, we observed a complete up/down shift (along magnetization axis) of hysteresis loop when the sample was cooled under a magnetic field of ± 5000 Oe in the in-plane configuration. We believe that the strong antiferromagnetic (super) exchange coupling of Mn-Cr across the two interfaces is responsible for the observed exchange bias. We will present and discuss our in-detailed experimental findings collected on this heterostructure as a function of temperature and magnetic field

    Amelioration of Abnormalities Associated with the Metabolic Syndrome by Spinacia oleracea

    Get PDF
    The present study evaluates the protective effects of an antioxidant-rich extract of Spinacea oleracea (NAOE) in abnormalities associated with the metabolic syndrome (MetS) in rats. HPTLC of NAOE revealed the presence of 13 total antioxidants, 14 flavonoids, and 10 phenolic acids. Rats administered with fructose (20% w/v) in drinking water for 45 days to induce abnormalities of MetS received NAOE (200 and 400 mg/kg, po), the standard drug gemfibrozil (60 mg/kg, po), aerobic exercise (AE), and a combination of NAOE 400 mg/kg and AE (NAOEAE) daily for 45 days. All treatments significantly altered the lipid profile and attenuated the fructose-elevated levels of uric acid, C-reactive protein, homocysteine, and marker enzymes (AST, LDH, and CK-MB) in serum and malondialdehyde in the heart and restored the fructose-depleted levels of glutathione and antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase). A significant decrease in blood glucose and insulin levels decreased insulin resistance, and improved glucose tolerance was observed in the treatment animals when compared with the fructose-fed animals. The best mitigation of MetS was shown by the NAOEAE treatment indicating that regular exercise along with adequate consumption of antioxidant-rich foods such as spinach in diet can help control MetS

    Antihypertensive response to prolonged tempol in the spontaneously hypertensive rat

    Get PDF
    Antihypertensive response to prolonged tempol in the spontaneously hypertensive rat.IntroductionTempol is a permeant nitroxide superoxide dismutase (SOD) mimetic that lowers mean arterial pressure (MAP) in spontaneously hypertensive rats (SHRs). We investigated the hypothesis that the antihypertensive response entails a negative salt balance, blunting of plasma renin activity (PRA), endothelin-1 (ET-1), or catecholamines or correction of oxidative stress as indexed by 8-isoprostane prostaglandin F2α (PGF2α) (8-Iso).MethodsGroups (N = 6 to 8) of SHRs were infused for 2 weeks with vehicle or tempol (200 nmol/kg/min) or given tempol (2 mmol/L) in drinking water.ResultsTempol infusion reduced the MAP of anesthetized SHRs (150 ± 5 vs. 126 ± 6mm Hg) (P < 0.005). Oral tempol did not change the heart rate but reduced the MAP of conscious SHRs (-23 ± 6mm Hg) (P < 0.01) but not Wistar-Kyoto (WKY) rats. Tempol infusion increased the PRA (2.2 ± 0.2 vs. 5.0 ± 0.9 ng/mL/hour) (P < 0.005), did not change excretion of nitric oxide (NO) [NO2 + NO3 (NOx)], ET-1, or catecholamines but reduced excretion of 8-Iso (13.2 ± 1.4 vs. 9.6 ± 0.9 ng/24 hours; P < 0.01). Cumulative Na+ balance and gain in body weight were unaltered by tempol infusion. Tempol prevented a rise in MAP with high salt intake.ConclusionTempol corrects hypertension without a compensatory sympathoadrenal activation or salt retention. The response is independent of nitric oxide, endothelin, or catecholamines and occurs despite increased PRA. It is accompanied by a reduction in oxidative stress and is maintained during increased salt intake
    • …
    corecore