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1.
Phys Rev Lett ; 132(21): 216502, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38856271

RESUMO

Using spin-echo nuclear magnetic resonance in the model transverse field Ising system TmVO_{4}, we show that low frequency quantum fluctuations at the quantum critical point have a very different effect on ^{51}V nuclear spins than classical low-frequency noise or fluctuations that arise at a finite temperature critical point. Spin echoes filter out the low-frequency classical noise but not the quantum fluctuations. This allows us to directly visualize the quantum critical fan and demonstrate the persistence of quantum fluctuations at the critical coupling strength in TmVO_{4} to high temperatures in an experiment that remains transparent to finite temperature classical phase transitions. These results show that while dynamical decoupling schemes can be quite effective in eliminating classical noise in a qubit, a quantum critical environment may lead to rapid entanglement and decoherence.

2.
Prev Sci ; 24(Suppl 1): 40-49, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36399222

RESUMO

Given increasing opioid overdose mortality rates in the USA over the past 20 years, accelerating the implementation of prevention interventions found to be effective is critical. The Helping End Addiction Long-Term (HEAL) Prevention Cooperative (HPC) is a consortium of research projects funded to implement and test interventions designed to prevent the onset or escalation of opioid misuse among youth and young adults. The HPC offers a unique opportunity to synthesize and share lessons learned from participating research projects' varied implementation experiences, which can facilitate quicker integration of effective prevention interventions into practice. This protocol paper describes our hybrid approach to collecting and analyzing information about the implementation experiences of nine of the HPC research projects while they maintain their focus on assessing the effectiveness and cost-effectiveness of prevention interventions. To better understand implementation within this context, we will address five research questions: (1) What were the context and approach for implementing the prevention interventions, and how was the overall implementation experience? (2) How representative of the target population are the participants who were enrolled and retained in the research projects' effectiveness trials? (3) For what purposes and how were stakeholders engaged by the research projects? (4) What are the adaptable components of the prevention interventions? And finally, (5) how might implementation of the prevention interventions vary for non-trial implementation? This work will result in intervention-specific and general practical dissemination resources that can help potential adopters and deliverers of opioid misuse prevention make adoption decisions and prepare for successful implementation.


Assuntos
Comportamento Aditivo , Overdose de Drogas , Transtornos Relacionados ao Uso de Opioides , Adolescente , Adulto Jovem , Humanos , Overdose de Drogas/prevenção & controle , Transtornos Relacionados ao Uso de Opioides/prevenção & controle
3.
J Food Sci Technol ; 60(4): 1209-1221, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36936112

RESUMO

Khoa and khoa based products (burfi, peda, kalakand, milk cake, etc.) are a category of traditional dairy products of Indian subcontinent. They are prepared by open pan desiccation along with stirring and scraping of milk to the desired consistency, followed by addition of sugar and / or colour and flavoring ingredients. The peculiar sensory attributes developed during their course of preparation makes them unique, but their short shelf-life is a major challenge faced by the dairy industries. They are spoiled mainly because of yeast and mold growth along with detrimental changes in the sensory attributes. This review describes various preservation techniques explored in the last two decades such as packaging interventions, modified atmospheric and active packaging, chemical preservation, water activity modification, natural preservation, thermal treatments, bio-preservation, etc. which can be used either singly or in combination (hurdle technology), to enhance the shelf life of these milk products.

4.
J Food Sci Technol ; 58(9): 3388-3396, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34366456

RESUMO

In the present study, process parameters were optimized for the production of desiccated chhana-murki (Indian cottage cheese-based dessert). Response Surface Methodology (RSM) was employed to explore the mutual effects of coagulation temperature (CT) of milk (70-90 °C), % fat level in milk (3.5%-5.5%), and sugar-to-paneer cube (SP) ratio (0.6-0.9) on instrumental hardness (N), water activity (aw), yield (%), sensory sweetness and overall acceptability (on 100-point intensity scale) of chhana-murki. The resulted responses were evaluated by analysis of variance (ANOVA), and the second-order polynomial response surface equations were fitted using multiple regression analysis. Determination coefficients (R 2) were equal to 80% or higher for individual responses stated that the developed models were well fitted to the experimental results. The optimized product was prepared using CT 79.22 °C, milk fat 4.8%, and SP ratio 0.7. Confirmatory experiment values for instrument hardness, water activity (aw), yield (%), sensory sweetness and overall acceptability were 105.05 N, 0.85, 115.2%, 61.2 and 78.8, respectively.

5.
Lupus ; 27(10): 1577-1581, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30016928

RESUMO

Despite a marked improvement in 10-year survival for systemic lupus erythematosus (SLE) patients over the past five decades, mortality rates from SLE remain high compared to those in the general population. SLE was also among the leading causes of death in young women in the United States during 2000-2015. However, it is encouraging that SLE mortality rates and the ratios of SLE mortality rates to non-SLE mortality rates have decreased every year since the late 1990s. Despite this improvement, disparities in SLE mortality persist according to sex, race, age, and place of residence. Furthermore, demographic and geographic variables seem to modify the effect of each other in influencing SLE mortality, leading to interactions between sex/race/ethnicity-associated factors and geographic differences. In other words, individuals of the same sex/race/ethnicity had differences in SLE mortality depending on where they lived. These observations highlight SLE as an important public health issue. The recognition of SLE as a leading cause of death in the general population might spur targeted public health programs and research funding to address the high lupus mortality.


Assuntos
Saúde Global/tendências , Lúpus Eritematoso Sistêmico/mortalidade , Distribuição por Idade , Anti-Inflamatórios/uso terapêutico , Causas de Morte , Feminino , Humanos , Imunossupressores/uso terapêutico , Incidência , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Lúpus Eritematoso Sistêmico/etnologia , Masculino , Mortalidade/tendências , Prognóstico , Fatores de Risco , Distribuição por Sexo , Fatores de Tempo
6.
Br J Surg ; 104(12): 1620-1627, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28940403

RESUMO

BACKGROUND: The aim of this RCT was to determine whether radiologically inserted gastrostomy (RIG) in children is associated with more complications than percutaneous endoscopic gastrostomy (PEG). METHODS: Children at a single tertiary children's hospital requiring a primary gastrostomy were randomized to PEG or RIG. Patients were followed by assessors blinded to the insertion method. Complications were recorded, assigned a severity score, and analysed by zero-inflated Poisson regression analysis on an intention-to-treat basis, adjusting for length of follow-up. RESULTS: Over a 3-year period, 214 children were randomized (PEG, 107; RIG, 107), of whom 100 received PEG and 96 RIG. There was no significant difference in the number of complications between PEG and RIG groups (P = 0·875), or in the complication score: patients undergoing RIG had a 1·04 (95 per cent c.i. 0·89 to 1·21) times higher complication score than those who underwent PEG (P = 0·597). Only age had an independent significant effect on complication score, with older patients having a 0·97 (0·95 to 1·00) times lower complication score per year. CONCLUSION: PEG and RIG are both safe methods of gastrostomy insertion with a low rate of major complications. Registration number: NCT01920438 ( http://www.clinicaltrials.gov).


Assuntos
Gastroscopia/métodos , Gastrostomia/métodos , Criança , Pré-Escolar , Método Duplo-Cego , Gastroscopia/efeitos adversos , Gastrostomia/efeitos adversos , Humanos , Lactente , Complicações Pós-Operatórias , Estudos Prospectivos , Radiografia
7.
Phys Rev Lett ; 117(23): 237203, 2016 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-27982654

RESUMO

Sr_{2}CuTeO_{6} presents an opportunity for exploring low-dimensional magnetism on a square lattice of S=1/2 Cu^{2+} ions. We employ ab initio multireference configuration interaction calculations to unravel the Cu^{2+} electronic structure and to evaluate exchange interactions in Sr_{2}CuTeO_{6}. The latter results are validated by inelastic neutron scattering using linear spin-wave theory and series-expansion corrections for quantum effects to extract true coupling parameters. Using this methodology, which is quite general, we demonstrate that Sr_{2}CuTeO_{6} is an almost ideal realization of a nearest-neighbor Heisenberg antiferromagnet but with relatively weak coupling of 7.18(5) meV.

8.
Indian J Crit Care Med ; 20(7): 404-8, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27555694

RESUMO

AIMS: This study was conducted retrospectively to define early demographic and clinical predictors for acute kidney injury (AKI) among snake bite patients at the time of hospital admission. MATERIALS AND METHODS: We analyzed 138 cases with a poisonous snake bite. Patients were classified into two groups according to the presence and absence of AKI. The data regarding clinical features and demographic profile of these patients were collected from the hospital records in a prestructured pro forma and statistically compared. RESULTS: Of the 138 patients of venomous snake bite, 62 developed AKI (44.92%). Patients who developed AKI were older in age. Moreover, prolonged bite to anti-snake venom (ASV) time had a significant relationship in developing AKI (P < 0.05). Among the clinical features, there was an independent positive association of AKI with abdomen pain, tenderness and vomiting, cellulitis, bleeding tendencies, myalgia, and black or brown urine (P < 0.05). Neurological features were inversely associated with renal involvement. CONCLUSION: We found that marked abdominal pain, tenderness and vomiting, myalgia, black or brown urine, bite site cellulitis, bleeding tendencies, and prolonged (>2 h) bite to ASV time were significantly associated with the development of AKI in snake bite patients.

9.
Phys Rev Lett ; 115(26): 267208, 2015 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-26765024

RESUMO

If magnetic frustration is most commonly known for undermining long-range order, as famously illustrated by spin liquids, the ability of matter to develop new collective mechanisms in order to fight frustration is perhaps no less fascinating, providing an avenue for the exploration and discovery of unconventional behaviors. Here, we study a realistic minimal model where a number of such mechanisms converge, which, incidentally, pertain to the perplexing quantum spin ice candidate Yb(2)Ti(2)O(7). Specifically, we explain how thermal and quantum fluctuations, optimized by order-by-disorder selection, conspire to expand the stability region of a degenerate continuous U(1) manifold against the classical splayed ferromagnetic ground state that is displayed by the sister compound Yb(2)Ti(2)O(7). The resulting competition gives rise to multiple phase transitions, in striking similitude with recent experiments on Yb(2)Ti(2)O(7) [Lhotel et al., Phys. Rev. B 89, 224419 (2014)]. By combining a gamut of numerical techniques, we obtain compelling evidence that such multiphase competition is a natural engine for the substantial sample-to-sample variability observed in Yb(2)Ti(2)O(7) and is the missing key to ultimately understand the intrinsic properties of this material. As a corollary, our work offers a pertinent illustration of the influence of chemical pressure in rare-earth pyrochlores.

10.
Crit Rev Food Sci Nutr ; 55(1): 94-122, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24915396

RESUMO

Since ancient times, herbs have been used as natural remedies for curing many physiological disorders. Traditional medicinal literature appreciated their value as nature's gift to mankind for the healing of illnesses. Some of the herbs have also been used for culinary purposes, and few of them have been used in cheese manufacture both as coagulating agents and flavor ingredients. Scientific investigations regarding biological activity and toxicity of chemical moieties present in many herbs have been carried out over a period of time. Consequently, literature related to the use of herbs or their functional ingredients in foods and their interaction with food constituents has been appearing in recent times. This article presents the information regarding some biologically active constituents occurring in commonly used herbs, viz., alkaloids, anthraquinones, bitters, flavonoids, saponins, tannins, and essential oils, their physiological functionalities, and also the description of few herbs of importance, viz., Asparagus racemosus, Withania somnifera, Bacopa monniera, Pueraria tuberose, Emblica officinalis, Terminalia chebula, Terminalia belerica, Terminalia arjuna, and Aloe vera, in terms of their chemical composition, biological functionality, and toxicity. This article also reviews the use of herbs and their active ingredients in foods and their interactions with different food constituents.


Assuntos
Suplementos Nutricionais/análise , Análise de Alimentos , Plantas Medicinais/química , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia
11.
J Food Sci Technol ; 52(2): 1089-95, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25694723

RESUMO

The medicinal benefits of herbs could be conveyed via certain foods as carriers. Milk is one of the important carrier which has been effectively used to deliver phytochemicals presents in herbs (mainly polyphenols) for targeted health benefits in the traditional Indian system of medical science. The present study was conducted to evaluate the effect of herb components (Pueraria tuberosa) on properties of Pueraria tuberosa-milk model system. The herb was added into cow milk on the basis of sensory evaluation (0.4 %) by using 9-point hedonic scale. The physical and chemical changes were evaluated after various processing treatments viz. pasteurization (72 °C, 15 s), sterilization (121 °C, 15 min), separation etc. These changes were determined using viscosity, hydroxy methyl furfural (HMF) value, ethanol stability, colour characteristics and trolox equivalent antioxidant capacity (TEAC). It was observed that addition of Pueraria tuberosa to milk resulted in decreased HMF content, ethanol stability and lightness whereas antioxidant activity, redness and yellowness increased as compared to control. It can be concluded that addition of Pueraria tuberosa to milk at 0.4 % concentration altered the functional properties of milk and Pueraira tuberosa could be suitable for preparation of low heat treated functional dairy food products.

12.
J Food Sci Technol ; 52(2): 1176-81, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25694736

RESUMO

The effects of interaction of Asparagus racemosus (shatavari) with milk constituents and physico-chemical and functional characteristics of milk was studied. Addition of freeze dried aqueous shatavari extract at a concentration of 1 g /100 ml of milk showed a decrease in pH, rennet coagulation time and an increase in acidity, viscosity and heat stability at maximum. The extract also imparted brown colour to milk and showed an increase in a* (redness) and b* (yellowness) values but a decrease in L* (lightness) value. Proteins in milk were modified by reaction with shatavari extract. The derivatives formed were characterized in terms of SDS-PAGE. Electrophoretic pattern of sodium caseinate and whey containing 1% shatavari herb extract did not show any difference in band pattern i.e. there was no difference in mobility based on size of the proteins, but the intensity (width) of bands differed.

13.
J Physiol ; 592(14): 3127-41, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24801305

RESUMO

Maternal hypoxia is a common perturbation that can disrupt placental and thus fetal development, contributing to neonatal impairments. Recently, evidence has suggested that physiological outcomes are dependent upon the sex of the fetus, with males more susceptible to hypoxic insults than females. This study investigated the effects of maternal hypoxia during mid- to late gestation on fetal growth and placental development and determined if responses were sex specific. CD1 mice were housed under 21% or 12% oxygen from embryonic day (E) 14.5 until tissue collection at E18.5. Fetuses and placentas were weighed before collection for gene and protein expression and morphological analysis. Hypoxia reduced fetal weight in both sexes at E18.5 by 7% but did not affect placental weight. Hypoxia reduced placental mRNA levels of the mineralocorticoid and glucocorticoid receptors and reduced the gene and protein expression of the glucocorticoid metabolizing enzyme HSD11B2. However, placentas of female fetuses responded differently to maternal hypoxia than did placentas of male fetuses. Notably, morphology was significantly altered in placentas from hypoxic female fetuses, with a reduction in placental labyrinth blood spaces. In addition mRNA expression of Glut1, Igf2 and Igf1r were reduced in placentas of female fetuses only. In summary, maternal hypoxia altered placental formation in a sex specific manner through mechanisms involving placental vascular development, growth factor and nutrient transporter expression and placental glucocorticoid signalling. This study provides insight into how sex differences in offspring disease development may be due to sex specific placental adaptations to maternal insults.


Assuntos
Hipóxia/metabolismo , Placenta/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/metabolismo , Sistema A de Transporte de Aminoácidos/genética , Animais , Glicemia/análise , Corticosterona/sangue , Feminino , Transportador de Glucose Tipo 1/genética , Fator de Crescimento Insulin-Like II/genética , Masculino , Camundongos , Placentação , Gravidez , RNA Mensageiro/metabolismo , Receptor IGF Tipo 1/genética , Caracteres Sexuais
14.
Br J Cancer ; 111(10): 2014-23, 2014 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-25314059

RESUMO

BACKGROUND: In a clinical diagnostic laboratory, we evaluated the applicability of the Ion Proton sequencer for screening 409 cancer-related genes in solid tumours. METHODS: DNA was extracted from formalin-fixed, paraffin-embedded (FFPE) tissue biopsy specimens of 55 solid tumours (20 with matched normal tissue) and four cell lines and screened for mutations in 409 genes using the Ion Proton system. The mutation profiles of these samples were known based on prior testing using the Ion Torrent Personal Genome Machine (46-gene hotspot panel), Sanger sequencing, or fluorescence in situ hybridisation (FISH). Concordance with retrospective findings and additional mutations were evaluated. Assay sensitivity and reproducibility were established. Gene copy number variations (CNVs) detected were confirmed by molecular inversion probe (MIP) array. RESULTS: The average Ion Proton (409-gene panel) sequencing output per run was 8 gigabases with 128 million sequencing reads. Of the 15,992 amplicons in the 409-gene panel, 90% achieved a minimum average sequencing depth of 100X. In 59 samples, the Ion Proton detected 100 of 105 expected single-nucleotide variants (SNVs) and all expected deletions (n=8), insertions (n=5), and CNVs (n=7). Five SNVs were not detected due to failed amplification of targeted regions. In 20 tumours with paired normal tissue, Ion Proton detected 37 additional somatic mutations, several in genes of high prognostic or therapeutic significance, such as MET, ALK, TP53, APC, and PTEN. MIP array analysis confirmed all CNVs detected by Ion Proton. CONCLUSIONS: The Ion Proton (409-gene panel) system was found to be well suited for use in a clinical molecular diagnostic laboratory. It can simultaneously screen 409 genes for a variety of sequence variants in multiple samples using a low input of FFPE DNA with high reproducibility and sensitivity.


Assuntos
Variações do Número de Cópias de DNA , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mutação/genética , Proteínas de Neoplasias/genética , Neoplasias/diagnóstico , Neoplasias/genética , DNA/análise , DNA/genética , Humanos , Hibridização in Situ Fluorescente , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes
15.
J Food Sci Technol ; 51(10): 2727-33, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25328218

RESUMO

The antioxidant activities of vidarikand (Pueraria tuberosa), shatavari (Asparagus racemosus) and ashwagandha (Withania somnifera) extracts (aqueous and ethanolic) were evaluated and compared with BHA using ß-carotene bleaching assay, DPPH assay and Rancimat method. Phenolic contents of ethanolic extracts of herbs were high compared to their aqueous extracts. The ethanolic extracts showed more antioxidant activity (ß-carotene-linoleic acid model system) than their aqueous counterparts. In DPPH system also, ethanolic extracts were superior to that of aqueous extracts. The ethanolic extracts of the herbs were more effective in preventing the development of the peroxide value and conjugated diene in ghee compared to their aqueous extracts. Ethanolic extracts of herbs showed the higher induction period as compared to their aqueous counter parts in the Rancimat. Antioxidant activity of the herbs decreased in the order vidarikand > ashwagandha > shatavari. Thus, the ethanolic extract of vidarikand was having the maximum antioxidant activity among all the herbs.

16.
Clin Exp Immunol ; 173(1): 18-27, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23607366

RESUMO

Patients with systemic lupus erythematosus (SLE) display reduced numbers and functions of invariant natural killer T (iNK T) cells, which are restored upon treatment with corticosteroids and rituximab. It is unclear whether the iNK T cell insufficiency is a consequence of disease or is a primary abnormality that precedes the onset of disease. To address this, we analysed iNK T cell function at different stages of disease development using the genetically lupus-susceptible NZB × NZW F1 (BWF(1)) model. We found that iNK T cell in-vivo cytokine responses to an iNK T cell ligand α-galactosylceramide (α-GalCer) were lower in BWF(1) mice than in non-autoimmune BALB/c and major histocompatibility complex (MHC)-matched NZB × N/B10.PL F1 mice, although iNK T cell numbers in the periphery were unchanged in BWF(1) mice compared to control mice. Such iNK T cell hyporesponsiveness in BWF(1) mice was detected at a young age long before the animals exhibited any sign of autoimmunity. In-vivo activation of iNK T cells is known to transactivate other immune cells. Such transactivated T and B cell activation markers and/or cytokine responses were also lower in BWF(1) mice than in BALB/c controls. Finally, we show that iNK T cell responses were markedly deficient in the NZB parent but not in NZW parent of BWF(1) mice, suggesting that BWF(1) might inherit the iNK T cell defect from NZB mice. Thus, iNK T cells are functionally insufficient in lupus-prone BWF(1) mice. Such iNK T cell insufficiency precedes the onset of disease and may play a pathogenic role during early stages of disease development in SLE.


Assuntos
Lúpus Eritematoso Sistêmico/imunologia , Células T Matadoras Naturais/imunologia , Sintomas Prodrômicos , Animais , Antígenos CD1/imunologia , Células Cultivadas/imunologia , Células Cultivadas/metabolismo , Cruzamentos Genéticos , Modelos Animais de Doenças , Feminino , Galactosilceramidas/imunologia , Humanos , Lúpus Eritematoso Sistêmico/etiologia , Ativação Linfocitária , Cooperação Linfocítica , Contagem de Linfócitos , Linfocinas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NZB , Células T Matadoras Naturais/metabolismo
17.
J Food Sci Technol ; 50(2): 346-52, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24425926

RESUMO

In order to assess the shelf life of a low fat spread (LFS) based on ghee, the product with (PS) and without (CS) added 0.05 % (w/w) preservative potassium sorbate and packaged in 200 g polystyrene tubs was stored at 5 °C and evaluated for changes in sensory, physico-chemical and microbiological properties. On the basis of flavour score, the PS spread could be stored for 10 weeks without appreciable loss in quality as against the CS spread which could be stored only for 5 weeks. From the point of view of spreadability, body and texture and colour, the CS product was acceptable even after 11 weeks of storage. Use of preservative had an inhibitory effect on the development of free fatty acids (FFA) and thiobarbituric acid (TBA) reactive substances. While both the products showed an increasing tendency to whey off during storage, CS wheyed off more than PS. The two spreads showed similar oiling off, which increased slightly during the storage. Microbiologically, the ghee-based low fat spreads with and without preservative was stable for 9 and 3 weeks, respectively, from the view point of yeast and mould growth; but the preservative had little effect on the total viable count. Coliforms were absent in all the samples in fresh and during storage.

18.
Phys Rev Lett ; 109(9): 097205, 2012 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-23002878

RESUMO

We use numerical linked-cluster expansions to compute the specific heat C(T) and entropy S(T) of a quantum spin ice Hamiltonian for Yb2Ti2O7 using anisotropic exchange interactions, recently determined from inelastic neutron scattering measurements, and find good agreement with experimental calorimetric data. This vindicates Yb2Ti2O7 as a model quantum spin ice. We find that in the perturbative weak quantum regime, such a system has a ferrimagnetic ordered ground state, with two peaks in C(T): a Schottky anomaly signaling the paramagnetic to spin ice crossover, followed at a lower temperature by a sharp peak accompanying a first-order phase transition to the ordered state. We suggest that the two C(T) features observed in Yb2Ti2O7 are associated with the same physics. Spin excitations in this regime consist of weakly confined spinon-antispinon pairs. We anticipate that the conventional ground state with exotic quantum dynamics will prove a prevalent characteristic of many real quantum spin ice materials.

19.
Lupus ; 21(5): 485-90, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22065098

RESUMO

Some T cells react with lipid antigens bound to antigen-presenting molecule CD1d. Numbers and functions of a subset of such lipid-reactive T cells are reduced in patients with systemic lupus erythematosus (SLE) and their relatives, as well as in genetically susceptible and chemically induced animal models of lupus-like disease. We have reported that the germline deletion of CD1d exacerbates lupus, suggesting a protective role of these cells in the development of lupus. The use of a knockout mouse model in this study, however, did not allow examination of the role of these cells at different stages of disease. Here, we describe an approach to deplete CD1d-dependent T cells, which allowed us to investigate the role of these cells at different stages of disease in genetically lupus-prone NZB/NZW F1 (BWF1) mice. Repeated intravenous injections of large numbers of CD1d-transfected cells resulted in ∼50-75% reduction in these cells, as defined by the expression of CD4, NK1.1 and CD122, and lack of expression of CD62 ligand. TCR γδ (+)NK1.1(+) cells were also reduced in the recipients of CD1d-transfected cells as compared with control recipients. Such depletion of CD1d-reactive T cells in preclinical BWF1 mice resulted in disease acceleration with a significant increase in proteinuria and mortality. In older BWF1 mice having advanced nephritis, however, such depletion of CD1d-reactive T cells resulted in some disease improvement. Taken together, these data as well as our published studies suggest that CD1d-reactive T cells protect against the development of lupus in animal models. However, these cells appear to be unable to suppress established lupus nephritis in these animals, and might even play a disease aggravating role in late stages of disease.


Assuntos
Antígenos CD1d/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Nefrite Lúpica/imunologia , Linfócitos T/imunologia , Fatores Etários , Animais , Antígenos CD1d/genética , Modelos Animais de Doenças , Progressão da Doença , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/fisiopatologia , Nefrite Lúpica/fisiopatologia , Camundongos , Camundongos Endogâmicos NZB , Camundongos Knockout
20.
Phys Rev Lett ; 106(6): 067002, 2011 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-21405486

RESUMO

Although the parent iron-based pnictides and chalcogenides are itinerant antiferromagnets, the use of local moment picture to understand their magnetic properties is still widespread. We study magnetic Raman scattering from a local moment perspective for various quantum spin models proposed for this new class of superconductors. These models vary greatly in the level of magnetic frustration and show a vastly different two-magnon Raman response. Light scattering by two-magnon excitations thus provides a robust and independent measure of the underlying spin interactions. In accord with other recent experiments, our results indicate that the amount of magnetic frustration in these systems may be small.

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