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1.
Res Vet Sci ; 172: 105253, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38579632

RESUMO

The aim of the study was to examine the effects of repeated administrations of antioxidant multiminerals and vitamins in transition buffaloes on udder defense mechanism, antioxidant activity and occurrence of intramammary infection (IMI) in early lactation period. Forty clinically healthy pregnant buffaloes were enrolled 45 days before expected date of calving and randomly allocated into five different supplementation groups (n = 8): only basal ration (control), vitamin E and selenium (VES), multiminerals (MM), ascorbic acid (AA) and chromium (Cr) picolinate in basal diet. The udder defense mechanism was monitored by measuring phagocytic activity (PA), myeloperoxidase (MPO) and nitric oxide (NO) productions in milk leukocytes, antioxidant activity was evaluated by measuring total antioxidant capacity (TAC) in plasma and occurrence of IMI was assessed by milk cytology, bacterial count in milk and visible clinical signs of udder until day 28 post-calving. The results showed that the VES and MM supplementations exhibited significantly higher PA, MPO and NO productions of milk leukocytes till first week of lactation whereas, elevated mean TAC in plasma was maintained from day -7 to 1 of calving in MM supplementation group as compared to control group. Statistically, no significant difference in occurrences of subclinical or clinical IMI was noted across the groups until four weeks of lactation. Taken together, it is concluded that repeated administrations of VES and MM to transition buffaloes could be an effective strategy to maintain good udder health by augmenting milk leukocyte functions and antioxidant status and preventing incidence of IMI in early lactation.


Assuntos
Antioxidantes , Búfalos , Suplementos Nutricionais , Lactação , Glândulas Mamárias Animais , Vitaminas , Animais , Feminino , Antioxidantes/administração & dosagem , Antioxidantes/metabolismo , Lactação/efeitos dos fármacos , Vitaminas/administração & dosagem , Vitaminas/farmacologia , Glândulas Mamárias Animais/efeitos dos fármacos , Leite/química , Dieta/veterinária , Ração Animal/análise , Minerais/administração & dosagem , Gravidez , Distribuição Aleatória
2.
Plant Biol (Stuttg) ; 26(2): 145-156, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38194349

RESUMO

Mycorrhization has been an integral part of plants since colonization by the early land plants. Over decades, substantial research has highlighted its potential role in improving nutritional efficiency and growth, development and survival of crop plants. However, the focus of this review is trees. Evidence have been provided to explain ecological and physiological significance of mycorrhization in trees. Advances in recent technologies (e.g., metagenomics, artificial intelligence, machine learning, agricultural drones) may open new windows to apply this knowledge in promoting tree growth in forest ecosystems. Dual mycorrhization relationships in trees and even triple relationships among trees, mycorrhizal fungi and bacteria offer an interesting physiological system to understand how plants interact with other organisms for better survival. Besides, studies indicate additional roles of mycorrhization in learning, memorizing and communication between host trees through a common mycorrhizal network (CMN). Recent observations in trees suggest that mycorrhization may even promote tolerance to multiple abiotic (e.g., drought, salt, heavy metal stress) and biotic (e.g. fungi) stresses. Due to the extent of physiological reliance, local adaptation of trees is heavily impacted by the mycorrhizal community. This knowledge opens the possibility of a non-GMO avenue to promote tree growth and development. Indeed, mycorrhization could impact growth of trees in nurserys and subsequent survival of the inoculated trees in field conditions. Future studies might integrate hyperspectral imaging and drone technologies to identify tree communities that are deficient in nitrogen and spray mycorrhizal spore formulations on them.


Assuntos
Micorrizas , Árvores , Raízes de Plantas , Ecossistema , Inteligência Artificial , Micorrizas/fisiologia , Plantas/microbiologia
3.
J Phys Condens Matter ; 36(7)2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37883993

RESUMO

We report on the reentrant canonical semi spin-glass characteristics and controllable field-induced transitions in distorted Kagomé symmetry of (GeMn)Co2O4. ThisB-site spinel exhibits complicated, yet interesting magnetic behaviour in which the longitudinal ferrimagnetic (FiM) order sets in below the Néel temperatureTFN∼ 77 K due to uneven moments of divalent Co (↑ 5.33µB) and tetravalent Mn (↓ 3.87µB) which coexists with transverse spin-glass state below 72.85 K. Such complicated magnetic behaviour is suggested to result from the competing anisotropic superexchange interactions (JAB/kB∼ 4.3 K,JAA/kB∼ -6.2 K andJBB/kB∼ -3.3 K) between the cations, which is extracted following the Néel's expression for the two-sublattice model of FiM. Dynamical susceptibility (χac(f, T)) and relaxation of thermoremanent magnetization,MTRM(t) data have been analysed by means of the empirical scaling-laws such as Vogel-Fulcher law and Power law of critical slowing down. Both of which reveal the reentrant spin-glass like character which evolves through a number of intermediate metastable states. The magnitude of Mydosh parameter (Ω âˆ¼ 0.002), critical exponentzυ= (6.7 ± 0.07), spin relaxation timeτ0= (2.33 ± 0.1) × 10-18s, activation energyEa/kB= (69.8 ± 0.95) K and interparticle interaction strength (T0= 71.6 K) provide the experimental evidences for canonical spin-glass state below the spin freezing temperatureTF= 72.85 K. The field dependence ofTFobtained fromχac(T) follows the irreversibility in terms of de Almeida-Thouless mean-field instability in which the magnitude of crossover scaling exponent Φ turns out to be ∼2.9 for the (Ge0.8Mn0.2)Co2O4. Isothermal magnetization plots reveal two field-induced transitions across 9.52 kOe (HSF1) and 45.6 kOe (HSF2) associated with the FiM domains and spin-flip transition, respectively. Analysis of the inverse paramagnetic susceptibilityχp-1χp=χ-χ0after subtracting the temperature independent diamagnetic termχ0(=-3 × 10-3emu mol-1Oe-1) results in the effective magnetic momentµeff= 7.654µB/f.u. This agrees well with the theoretically obtainedµeff= 7.58µB/f.u. resulting the cation distributionMn0.24+↓A[Co22+↑]BO4in support of the Hund's ground state spin configurationS=3/2andS= 1/2of Mn4+and Co2+, respectively. TheH-Tphase diagram has been established by analysing all the parameters (TF(H),TFN(H),HSF1(T) andHSF2(T)) extracted from various magnetization measurements. This diagram enables clear differentiation among the different phases of the (GeMn)Co2O4and also illustrates the demarcation between short-range and long-range ordered regions.

4.
J Phys Condens Matter ; 35(37)2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37279725

RESUMO

Spinels (AB2O4) with magnetic ions occupying only the octahedralBsites have inherent magnetic frustration which inhibits magnetic long-range order (LRO) but may lead to exotic states. Here we report on the magnetic properties of the tetragonal spinel Zn0.8Cu0.2FeMnO4, the tetragonality resulting from the Jahn-Teller active Mn3+ions. X-ray diffraction and x-ray photoelectron spectroscopy of the sample yielded the composition (Zn0.82+Cu0.22+)A[Fe0.42+Fe0.63+Mn3+]BO4‒δ. Analysis of the temperature dependence of magnetization (M), ac magnetic susceptibilities (χ'andχ''), dc susceptibility (χ), heat capacityCp, and neutron diffraction (ND) measurements show complex temperature-dependent short-range order (SRO) but without LRO. The data ofχ vs. Tfits the Curie-Weiss law:χ = C/(T ‒ θ) fromT= 250 K to 400 K withθ≃ 185 K signifying dominant ferromagnetic (FM) coupling with the FM exchange constantJ/kB= 17 K, andC= 3.29 emu K mol‒1Oe‒1yielding an effective magnetic momentµeff= 5.13µBresulting from the high-spin states of Cu2+(Asite) and Fe2+(Bsite), while theBsite trivalent ions Mn3+and Fe3+are in their low-spin states. The extrapolated saturation magnetization obtained from theM vs. Hdata atT= 2 K is explained using the spin arrangement (Cu2+↓)A[Fe2+↑, Fe3+↓, Mn3+↑]Bleading to FM clusters interact antiferromagnetically at low temperatures. Temperature dependence of d(χT)/dTshows the onset of ferrimagnetism below ∼100 K and peaks near 47 K and 24 K. The relaxation timeτobtained from temperature and frequency dependence ofχ″when fit to the power law and Vogel-Fulcher laws confirm the cluster spin-glass (SG) state. The magnetic field dependence of the SG temperatureTSGHfollows the equation:TSGH=TSG01-AH2/ϕwithTSG(0) = 46.6 K,A= 8.6 × 10‒3Oe‒0.593andϕ= 3.37. The temperature dependence of hysteresis loops yields coercivityHC∼ 3.8 kOe at 2 K without exchange-bias, butHCdecreases with increase inTbecoming zero above 24 K, theTSG(H) forH= 800 Oe. Variations ofCpvs. Tfrom 2 K to 200 K inH=0 andH=90 kOe do not show any peak characteristic of LRO. However, after correcting for the lattice contribution, a broad weak peak typically of SRO becomes evident centered around 40 K. ForT< 9 K,Cpvaries asT2; a typical signature of spin-liquids (SLs). Comparison of the ND measurements at 1.7 K and 79.4 K shows absence of LRO. Time dependence of thermo-remanent magnetizationMTRM(t) studies below 9 K reveal weakening of the inter-cluster interaction with increase in temperature. A summary of these results is that in Zn0.8Cu0.2FeMnO4, ferromagnetic clusters interact antiferromagnetically without LRO but producing a cluster SG state atTSG(0) = 46.6 K, followed by SL behavior below 9 K.

5.
Mymensingh Med J ; 30(1): 73-78, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33397854

RESUMO

In adults, distal humerus fractures are infrequent and frequently intra-articular. Customarily encompass both medial and lateral columns. Operative management gives constructive outcomes. The aim of this study was to evaluate clinical outcome in intra articular distal humerus fractures in adults treated by different hardware. This prospective study consists of 20 purposively selected patients with intra articular distal humerus fractures treated by surgical intervention with different hardware who were admitted to Mymensingh Medical College and Hospital, Bangladesh in between November 2016 to October 2018. Surgical approaches were standard dorsal with or without olecranon osteotomy. The mean age of the patients was 32.3 years, range between 18-55 years. The maximum patients i.e. 85% were between 18-45 years. Seventy percent (70%) of the cases admitted were due to Road traffic accident (RTA). Most of the patients were males 14(70%) with right upper limb was involved in 13(65%) cases. Mean Mayo Elbow Performance Score was 81.5 post-operatively. According to Mayo Elbow Performance (MEP) score clinical outcome was excellent in 20%, good in 50%, fair in 25% and poor in 10% of patients. Distal humerus fractures are censorious in nature. Proper anatomical articular reconstruction and stable fixation by surgical intervention helps in fruitful results.


Assuntos
Articulação do Cotovelo , Fraturas do Úmero , Adolescente , Adulto , Bangladesh/epidemiologia , Articulação do Cotovelo/cirurgia , Fixação Interna de Fraturas , Humanos , Fraturas do Úmero/cirurgia , Úmero , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
6.
J Phys Condens Matter ; 32(24): 245801, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-32186281

RESUMO

A systematic study using neutron diffraction and magnetic susceptibility is reported on Mn substituted ferrimagnetic inverse spinel Ti1-x Mn x Co2O4 in the temperature interval 1.6 K [Formula: see text] T [Formula: see text] 300 K. Our neutron diffraction study reveals cooperative distortions of the TO6 octahedra in the Ti1-x Mn x Co2O4 system for all the Jahn-Teller active ions T = Mn3+ , Ti3+ and Co3+ , having the electronic configurations 3d 1, 3d 4 and 3d 6, respectively which are confirmed by the x-ray photoelectron spectroscopy. Two specific compositions (x = 0.2 and 0.4) have been chosen in this study because these two systems show unique features such as; (i) noncollinear Yafet-Kittel type magnetic ordering, and (ii) weak tetragonal distortion with c/a < 1, in which the apical bond length d c (T B -O) is longer than the equatorial bond length d ab (T B -O) due to the splitting of the e g level of Mn3+ ions into [Formula: see text] and [Formula: see text]. For the composition x = 0.4, the distortion in the T B O6 octahedra is stronger as compared to x = 0.2 because of the higher content of trivalent Mn. Ferrimagnetic ordering in Ti0.6Mn0.4Co2O4 and Ti0.8Mn0.2Co2O4 sets in at 110.3 and 78.2 K, respectively due to the presence of unequal magnetic moments of cations, where Ti3+ , Mn3+ , and Co3+ occupy the octahedral, whereas, Co2+ sits in the tetrahedral site. For both compounds an additional weak antiferromagnetic component could be observed lying perpendicular to the ferrimagnetic component. The analysis of static and dynamic magnetic susceptibilities combined with the heat-capacity data reveals a magnetic compensation phenomenon (MCP) at T COMP = 25.4 K in Ti0.8Mn0.2Co2O4 and a reentrant spin-glass behaviour in Ti0.6Mn0.4Co2O4 with a freezing temperature of ∼110.1 K. The MCP in this compound is characterized by sign reversal of magnetization and bipolar exchange bias effect below T COMP with its magnitude depending on the direction of external magnetic field and the cooling protocol.

7.
Nanoscale Adv ; 2(2): 851-859, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-36133229

RESUMO

Functional oxide nanocomposites, where the individual components belong to the family of strongly correlated electron oxides, are an important class of materials, with potential applications in several areas such as spintronics and energy devices. For these materials to be technologically relevant, it is essential to design low-cost and scalable synthesis techniques. In this work, we report a low-temperature and scalable synthesis of prototypical bi-magnetic LaFeO3-CoFe2O4 nanocomposites using a unique sol-based synthesis route, where both the phases of the nanocomposite are formed during the same time. In this bottom-up approach, the heat of formation of one phase (CoFe2O4) allows the crystallization of the second phase (LaFeO3), and completely eliminates the need for conventional high-temperature annealing. A symbiotic effect is observed, as the second phase reduces grain growth of the first phase, thus yielding samples with lower particle sizes. Through thermogravimetric, structural, and morphological studies, we have confirmed the reaction mechanism. The magnetic properties of the bi-magnetic nanocomposites are studied, and reveal a distinct effect of the synthesis conditions on the coercivity of the particles. Our work presents a basic concept of significantly reducing the synthesis temperature of bi-phasic nanocomposites (and thus also the synthesis cost) by using one phase as nucleation sites for the second one, as well as using the heat of formation of one phase to crystallize the other.

8.
Nanoscale ; 11(30): 14256-14265, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31318002

RESUMO

Magnetic nanocomposites constitute a vital class of technologically relevant materials, in particular for next-generation applications ranging from biomedicine, catalysis, and energy devices. Key to designing such materials is determining and controlling the extent of magnetic coupling in them. In this work, we show how the magnetic coupling in bi-magnetic nanocomposites can be controlled by the growth technique. Using four different synthesis strategies to prepare prototypical LaFeO3-CoFe2O4 and LaFeO3-Co0.5Zn0.5Fe2O4 nanocomposite systems, and by performing comprehensive magnetic measurements, we demonstrate that the final material exhibits striking differences in their magnetic coupling that is distinct to the growth method. Through structural and morphological studies, we confirm the link between the magnetic coupling and growth methods due to distinct levels of particle agglomeration at the very microscopic scale. Our studies reveal an inverse relationship between the strength of magnetic coupling and the degree of particle agglomeration in the nanocomposites. Our work presents a basic concept of controlling the particle agglomeration to tune magnetic coupling, relevant for designing advanced bi-magnetic nanocomposites for novel applications.

9.
Nanoscale ; 10(48): 22990-23000, 2018 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-30500041

RESUMO

The properties of magnetic nanocomposites rely strongly on the interplay between those of the constituent components. When the individual components themselves are complex systems belonging to the family of correlated electron oxide systems which typically exhibit exotic physical properties, it becomes nontrivial to customize the properties of the nanocomposite. In this paper, we demonstrate an easy, but effective method to synthesize and tune the magnetic properties of nanocomposites consisting of correlated electron oxide systems as the individual components. Our method is based on a novel synthesis technique by which the two components of the nanocomposite can be directly integrated with each other, yielding homogeneous samples on the nanoscale with magnetic behavior reminiscent of a single phase. We illustrate our method using multiferroic BiFeO3 (BFO) and LaFeO3 (LFO) as the major phase (i.e., matrix), and MFe2O4 (M = Co2+ or Ni2+) as the embedded magnetic phase. Furthermore, we show that by a proper selection of the second phase in the nanocomposite, it is possible to customize the magnetic properties of the matrix. We illustrate this by choosing CoFe2O4 and NiFe2O4, two oxides with widely differing magnetic anisotropies, as the embedded phase, and demonstrate that the coercivity of BFO and LFO can be increased or decreased depending on the choice of the embedded phase in the nanocomposite.

10.
Nature ; 563(7731): 374-378, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30429543

RESUMO

High-temperature copper oxide superconductors consist of stacked CuO2 planes, with electronic band structures and magnetic excitations that are primarily two-dimensional1,2, but with superconducting coherence that is three-dimensional. This dichotomy highlights the importance of out-of-plane charge dynamics, which has been found to be incoherent in the normal state3,4 within the limited range of momenta accessible by optics. Here we use resonant inelastic X-ray scattering to explore the charge dynamics across all three dimensions of the Brillouin zone. Polarization analysis of recently discovered collective excitations (modes) in electron-doped copper oxides5-7 reveals their charge origin, that is, without mixing with magnetic components5-7. The excitations disperse along both the in-plane and out-of-plane directions, revealing its three-dimensional nature. The periodicity of the out-of-plane dispersion corresponds to the distance between neighbouring CuO2 planes rather than to the crystallographic c-axis lattice constant, suggesting that the interplane Coulomb interaction is responsible for the coherent out-of-plane charge dynamics. The observed properties are hallmarks of the long-sought 'acoustic plasmon', which is a branch of distinct charge collective modes predicted for layered systems8-12 and argued to play a substantial part in mediating high-temperature superconductivity10-12.

11.
Oncogene ; 35(46): 5977-5988, 2016 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-27292262

RESUMO

Metastatic competence is contingent upon the aberrant activation of a latent embryonic program, known as the epithelial-mesenchymal transition (EMT), which bestows stem cell properties as well as migratory and invasive capabilities upon differentiated tumor cells. We recently identified the transcription factor FOXC2 as a downstream effector of multiple EMT programs, independent of the EMT-inducing stimulus, and as a key player linking EMT, stem cell traits and metastatic competence in breast cancer. As such, FOXC2 could serve as a potential therapeutic target to attenuate metastasis. However, as FOXC2 is a transcription factor, it is difficult to target by conventional means such as small-molecule inhibitors. Herein, we identify the serine/threonine-specific kinase p38 as a druggable upstream regulator of FOXC2 stability and function that elicits phosphorylation of FOXC2 at serine 367 (S367). Using an orthotopic syngeneic mouse tumor model, we make the striking observation that inhibition of p38-FOXC2 signaling selectively attenuates metastasis without impacting primary tumor growth. In this model, circulating tumor cell numbers are significantly reduced in mice treated with the p38 inhibitor SB203580, relative to vehicle-treated counterparts. Accordingly, genetic or pharmacological inhibition of p38 decreases FOXC2 protein levels, reverts the EMT phenotype and compromises stem cell attributes in vitro. We also identify the EMT-regulator ZEB1-known to directly repress E-cadherin/CDH1-as a downstream target of FOXC2, critically dependent on its activation by p38. Consistent with the notion that activation of the p38-FOXC2 signaling axis represents a critical juncture in the acquisition of metastatic competence, the phosphomimetic FOXC2(S367E) mutant is refractory to p38 inhibition both in vitro and in vivo, whereas the non-phosphorylatable FOXC2(S367A) mutant fails to elicit EMT and upregulate ZEB1. Collectively, our data demonstrate that FOXC2 regulates EMT, stem cell traits, ZEB1 expression and metastasis in a p38-dependent manner, and attest to the potential utility of p38 inhibitors as antimetastatic agents.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Fatores de Transcrição Forkhead/metabolismo , Serina/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Antineoplásicos/farmacologia , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal/genética , Feminino , Xenoenxertos , Humanos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Metástase Neoplásica , Células-Tronco Neoplásicas/metabolismo , Fenótipo , Fosforilação , Ligação Proteica , RNA Interferente Pequeno/genética
12.
Toxicol Rep ; 3: 346-350, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28959555

RESUMO

This study is aimed to assess the heavy metals contamination and health risk in Shrimp (Macrobrachium rosenbergii and Penaeus monodon) collected from Khulna-Satkhira region in Bangladesh. The results showed that the Pb concentrations (0.52-1.16 mg/kg) in all shrimp samples of farms were higher than the recommended limit. The Cd levels (0.05-0.13 mg/kg) in all samples and Cr levels in all farms except tissue content at Satkhira farm were higher than the permissible limits. The individual concentration of Pb, Cd, and Cr between shrimp tissue and shell in all rivers and farms were not statistically significant (P > 0.05). Target hazard quotient (THQ) and hazard index (HI) were estimated to assess the non-carcinogenic health risks. Shrimp samples from all locations under the current study were found to be safe for consumption, the possibility of health risk associated with non-carcinogenic effect is very low for continuous consumption for 30 years.

13.
Sci Rep ; 5: 13011, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-26265554

RESUMO

We report the observation of spatially separated Kondo scattering and ferromagnetism in anatase Ta0.06Ti0.94O2 thin films as a function of thickness (10-200 nm). The Kondo behavior observed in thicker films is suppressed on decreasing thickness and vanishes below ~25 nm. In 200 nm film, transport data could be fitted to a renormalization group theory for Kondo scattering though the carrier density in this system is lower by two orders of magnitude, the magnetic entity concentration is larger by a similar magnitude and there is strong electronic correlation compared to a conventional system such as Cu with magnetic impurities. However, ferromagnetism is observed at all thicknesses with magnetic moment per unit thickness decreasing beyond 10 nm film thickness. The simultaneous presence of Kondo and ferromagnetism is explained by the spatial variation of defects from the interface to surface which results in a dominantly ferromagnetic region closer to substrate-film interface while the Kondo scattering is dominant near the surface and decreasing towards the interface. This material system enables us to study the effect of neighboring presence of two competing magnetic phenomena and the possibility for tuning them.

14.
Cell Death Dis ; 6: e1773, 2015 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-26018734

RESUMO

Mature erythrocytes (red blood cells (RBCs)) undergo the programmed cell death (PCD) pathway of necroptosis in response to bacterial pore-forming toxins (PFTs) that target human CD59 (hCD59) but not hCD59-independent PFTs. Here, we investigate the biochemical mechanism of RBC necroptosis with a focus on the mechanism of induction and the minimal requirements for such RBC death. Binding or crosslinking of the hCD59 receptor led to Syk-dependent induction of vesiculated morphology (echinocytes) that was associated with phosphorylation of Band 3 and was required for Fas ligand (FasL) release. FasL-dependent phosphorylation of receptor-interacting protein kinase 1 (RIP1) in combination with plasma membrane pore formation was required for execution of RBC necroptosis. RIP1 phosphorylation led to the phosphorylation of RIP3, which was also critical for RBC necroptosis. Notably, RBC necroptosis was mediated by FasL and not by other candidate inducers, including tumor necrosis factor alpha (TNF-α) and TNF-related apoptosis-inducing ligand (TRAIL). Other types of RBC damage, such as eryptotic damage, failed to induce necroptosis when combined with hCD59 crosslinking. This work sheds light on the requirements for this recently discovered PCD in RBCs and provides a clear picture of the biochemical mechanism of induction of RBC necroptosis.


Assuntos
Antígenos CD59/metabolismo , Eritrócitos/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Necrose/imunologia , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Proteínas Tirosina Quinases/metabolismo , Antígenos CD55/imunologia , Antígenos CD55/metabolismo , Antígenos CD59/imunologia , Membrana Celular/patologia , Reagentes de Ligações Cruzadas/farmacologia , Proteína Ligante Fas/metabolismo , Humanos , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Fosforilação , Proteínas de Ligação a RNA/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Transdução de Sinais , Quinase Syk , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
15.
J Phys Condens Matter ; 27(16): 166001, 2015 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-25817434

RESUMO

In the spinel Co2SnO4, coexistence of ferrimagnetic ordering below T(N) ≃ 41 K followed by a spin glass state below T(SG) ≃ 39 K was proposed recently based on the temperature dependence of magnetization M(T) data. Here new measurements of the temperature dependence of the specific heat C(P)(T), ac-susceptibilities χ'(T) and χ″(T) measured at frequencies between 0.51 and 1.2 kHz, and the hysteresis loop parameters (coercivity H(C)(T) and remanence M(R)(T)) in two differently prepared samples of Co2SnO4 are reported. The presence of the Co(2+) and Sn(4+) states is confirmed by x-ray photoelectron spectroscopy (XPS) yielding the structure: Co2SnO4 = [Co(2+)][Co(2+)Sn(4+)]O4. The data of C(P) versus T shows only an inflection near 39 K characteristic of spin-glass ordering. The analysis of the frequency dependence of ac-magnetic susceptibility data near 39 K using the Vogel-Fulcher law and the power-law of the critical slowing-down suggests the presence of spin clusters in the system which is close to a spin-glass state. With a decrease in temperature below 39 K, the temperature dependence of the coercivity H(C) and remanence M(R) for the zero-field cooled samples show both H(C) and M(R) reaching their peak magnitudes near 25 K, then decreasing with decreasing T and becoming negligible below 15 K. The plot of C(P)/T versus T also yields a weak inflection near 15 K. This temperature dependence of H(C) and remanence M(R) is likely associated with the different magnitudes of the magnetic moments of Co(2+) ions on the 'A' and 'B' sites and their different temperature dependence.

16.
Oncogene ; 34(23): 2958-67, 2015 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-25109336

RESUMO

The epithelial-mesenchymal transition (EMT) bestows cancer cells with increased stem cell properties and metastatic potential. To date, multiple extracellular stimuli and transcription factors have been shown to regulate EMT. Many of them are not druggable and therefore it is necessary to identify targets, which can be inhibited using small molecules to prevent metastasis. Recently, we identified the ganglioside GD2 as a novel breast cancer stem cell marker. Moreover, we found that GD3 synthase (GD3S)--an enzyme involved in GD2 biosynthesis--is critical for GD2 production and could serve as a potential druggable target for inhibiting tumor initiation and metastasis. Indeed, there is a small molecule known as triptolide that has been shown to inhibit GD3S function. Accordingly, in this manuscript, we demonstrate that the inhibition of GD3S using small hairpin RNA or triptolide compromises the initiation and maintenance of EMT instigated by various signaling pathways, including Snail, Twist and transforming growth factor-ß1 as well as the mesenchymal characteristics of claudin-low breast cancer cell lines (SUM159 and MDA-MB-231). Moreover, GD3S is necessary for wound healing, migration, invasion and stem cell properties in vitro. Most importantly, inhibition of GD3S in vivo prevents metastasis in experimental as well as in spontaneous syngeneic wild-type mouse models. We also demonstrate that the transcription factor FOXC2, a central downstream effector of several EMT pathways, directly regulates GD3S expression by binding to its promoter. In clinical specimens, the expression of GD3S correlates with poor prognosis in triple-negative human breast tumors. Moreover, GD3S expression correlates with activation of the c-Met signaling pathway leading to increased stem cell properties and metastatic competence. Collectively, these findings suggest that the GD3S-c-Met axis could serve as an effective target for the treatment of metastatic breast cancers.


Assuntos
Neoplasias da Mama/patologia , Diterpenos/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fatores de Transcrição Forkhead/metabolismo , Fenantrenos/farmacologia , Proteínas Proto-Oncogênicas c-met/metabolismo , RNA Interferente Pequeno/farmacologia , Sialiltransferases/genética , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Compostos de Epóxi/farmacologia , Feminino , Humanos , Camundongos , Metástase Neoplásica , Neoplasias Experimentais , Prognóstico , Regiões Promotoras Genéticas , Sialiltransferases/antagonistas & inibidores , Sialiltransferases/metabolismo , Transdução de Sinais/efeitos dos fármacos
17.
J Phys Condens Matter ; 26(43): 435303, 2014 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-25299746

RESUMO

Elastic and anelastic properties of La0.5Ca0.5MnO3 determined by resonant ultrasound spectroscopy in the frequency range ∼100-1200 kHz have been used to evaluate the role of grain size in determining the competition between ferromagnetism and Jahn-Teller/charge order of manganites which show colossal magneto resistance. At crystallite sizes of ∼75 and ∼135 nm the dominant feature is softening of the shear modulus as the charge order transition point, Tco (∼225 K), is approached from above and below, matching the form of softening seen previously in samples with 'bulk' properties. This is consistent with a bilinear dominant strain/order parameter coupling, which occurs between the tetragonal shear strain and the Jahn-Teller (Γ3(+)) order parameter. At crystallite sizes of ∼34 and ∼42 nm the charge ordered phase is suppressed but there is still softening of the shear modulus, with a minimum near Tco. This indicates that some degree of pseudoproper ferroelastic behaviour is retained. The primary cause of the suppresion of the charge ordered structure in nanocrystalline samples is therefore considered to be due to suppression of macroscopic strain, even though MnO6 octahedra must develop some Jahn-Teller distortions on a local length scale. This mechanism for stabilizing ferromagnetism differs from imposition of either an external magnetic field or a homogeneous external strain field (from a substrate), and is likely to lead both to local strain heterogeneity within the nanocrystallites and to different tilting of octahedra within the orthorhombic structure. An additional first order transition occurs near 40 K in all samples and appears to involve some very small strain contrast between two ferromagnetic structures.

18.
Phys Rev E Stat Nonlin Soft Matter Phys ; 86(5 Pt 1): 052103, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23214830

RESUMO

A microscopic characterization, based on the thermodynamic curvature R, is proposed for first-order liquid-gas phase transitions. Near the critical point, where R is proportional to the correlation volume ξ(3), we propose that R takes the same value in the coexisting phases. This proposal allows a determination of the liquid-gas coexistence curve with no use of the problematic Maxwell equal area construction. Furthermore, |R| ~ ξ(3) allows a direct determination of the Widom line in the supercritical regime. We illustrate with input from the van der Waals model and the National Institute of Standards and Technology Chemistry WebBook.


Assuntos
Gases/química , Modelos Químicos , Transição de Fase , Soluções/química , Termodinâmica , Simulação por Computador
19.
J Indian Med Assoc ; 109(8): 543-5, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22315859

RESUMO

Rapid diagnosis of dengue infection is essential to patient management and disease control. In a rural tertiary health setting and diagnostic laboratories, dengue suspect cases were assessed with a rapid (15 minutes) immunochromatographic test and compared to an IgM capture enzyme-linked immunosorbent assay (ELISA) (2-3 days) and the reliability of the rapid test was tested. The objectives were to evaluate dengue rapid test against dengue IgM capture ELISA and to assess the scopes of such rapid tests in peripheral setting. A rapid immunochromatographic card test was compared with an IgM capture ELISA (National Institute of Virology, Pune, India) as the reference gold standard. The sensitivity and specificity of the test was compared over a period of five years in a rural tertiary hospital among 158 dengue suspects. The rapid test showed good sensitivity in the diagnosis of both primary and secondary dengue infection. The rapid test as confirmed by IgM capture ELISA was found to have specificity of 98.4% and a sensitivity of 96.4%.The positive predictive value was 93.1% and negative predictive value of 99.2%.The positive likelihood ratio worked out to be 62.6,with negative likelihood ratio was 0.036,signifying large impact. The rapid tests may be useful aid in screening in case of clinical diagnosis of dengue infection,particularly valuable in peripheral health settings,where it can hasten the initiation of firstline of management; while the ELISA has a place in central testing laboratories, aiding in resource optimisation.


Assuntos
Cromatografia de Afinidade , Dengue/diagnóstico , Cromatografia de Afinidade/métodos , Ensaio de Imunoadsorção Enzimática , Humanos , Reprodutibilidade dos Testes
20.
Rev Sci Tech ; 29(3): 695-703, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21309468

RESUMO

Thirty-seven yaks (Bos grunniens) with keratoconjunctivitis and 22 healthy yaks were used to investigate the role of bovine herpesvirus 1 (BoHV-1) in keratoconjunctivitis in yaks. Nucleic acid sequences of BoHV-1 glycoproteins B and E were detected in conjunctival swabs from all yaks with keratoconjunctivitis using a nested polymerase chain reaction (PCR). In 21 yaks, BoHV-1 sequences were detected along with Moraxella bovis (M. bovis) and Neisseria spp. The amplified BoHV-1 sequences were identical, and no nucleotide variation was observed when compared with a BoHV-1 reference strain using single-strand conformation polymorphism analysis of the amplified DNA sequences. Interestingly, BoHV-1 sequences could not be detected in samples from healthy yaks. However, conjunctival swabs from two healthy yaks (9.09%) yielded M. bovis and Neisseria spp. Samples from 35 yaks with keratoconjunctivitis showed positive reactions in an avidin biotin enzyme-linked immunosorbent assay for BoHV-1 antibodies; all the healthy yaks were seronegative. This is the first report of a possible association of BoHV-1 with keratoconjunctivitis in yaks.


Assuntos
Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 1/isolamento & purificação , Ceratoconjuntivite Infecciosa/virologia , Reação em Cadeia da Polimerase/veterinária , Animais , Anticorpos Antivirais/sangue , Estudos de Casos e Controles , Bovinos , Túnica Conjuntiva/virologia , DNA Viral/análise , Infecções por Herpesviridae/virologia , Herpesvirus Bovino 1/genética , Herpesvirus Bovino 1/imunologia , Reação em Cadeia da Polimerase/normas , Polimorfismo Conformacional de Fita Simples , Sensibilidade e Especificidade
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