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1.
Nature ; 626(7999): 517-522, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38356066

RESUMEN

Lifted Kramers spin degeneracy (LKSD) has been among the central topics of condensed-matter physics since the dawn of the band theory of solids1,2. It underpins established practical applications as well as current frontier research, ranging from magnetic-memory technology3-7 to topological quantum matter8-14. Traditionally, LKSD has been considered to originate from two possible internal symmetry-breaking mechanisms. The first refers to time-reversal symmetry breaking by magnetization of ferromagnets and tends to be strong because of the non-relativistic exchange origin15. The second applies to crystals with broken inversion symmetry and tends to be comparatively weaker, as it originates from the relativistic spin-orbit coupling (SOC)16-19. A recent theory work based on spin-symmetry classification has identified an unconventional magnetic phase, dubbed altermagnetic20,21, that allows for LKSD without net magnetization and inversion-symmetry breaking. Here we provide the confirmation using photoemission spectroscopy and ab initio calculations. We identify two distinct unconventional mechanisms of LKSD generated by the altermagnetic phase of centrosymmetric MnTe with vanishing net magnetization20-23. Our observation of the altermagnetic LKSD can have broad consequences in magnetism. It motivates exploration and exploitation of the unconventional nature of this magnetic phase in an extended family of materials, ranging from insulators and semiconductors to metals and superconductors20,21, that have been either identified recently or perceived for many decades as conventional antiferromagnets21,24,25.

2.
J Postgrad Med ; 65(3): 152-159, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31169134

RESUMEN

Aims: The primary objective of the present study was to evaluate the economic burden of specific learning disability (SpLD) by estimating its direct, indirect, and intangible costs. A secondary objective was to assess the impact of variables on the economic burden. Settings and Design: Cross-sectional single-arm descriptive study. Setting: Learning disability clinic in a public medical college in Mumbai. Subjects and Methods: The study cases (aged ≥8 years) were recruited by non-probability sampling. A structured questionnaire was used to interview the parent/guardian to collect data related to direct and indirect costs. Intangible costs data were collected by documenting the willingness-to-pay value using the contingent valuation technique. Statistical Analysis Used: A quantile regression model was used to assess the impact of predictor variables on the costs. Results: The direct, indirect, and intangible costs due to SpLD were Indian Rupees (INR) 5,936,053, 29,261,220, and 42,295,000, respectively. Indirect costs comprised 83.1% of the total costs. Expenditure on tuitions and remedial education comprised 61.61% and 64.39% of the indirect and direct costs, respectively. The average annual learning disability clinic costs were INR 2,169,888. The average annual total costs per student were INR 90,773. Longer duration of poor school performance was predictive of higher direct, indirect, and total costs; and higher socioeconomic status was predictive of lower intangible costs. Conclusion: SpLD is a cost-intensive disability (intangible > indirect > direct costs). Tuitions, which are not the therapy for SpLD, are the most costly component of indirect costs. Remedial education is the most costly component of direct costs.


Asunto(s)
Costo de Enfermedad , Educación Especial/economía , Costos de la Atención en Salud/estadística & datos numéricos , Discapacidades para el Aprendizaje/economía , Adolescente , Niño , Estudios Transversales , Femenino , Humanos , India/epidemiología , Discapacidades para el Aprendizaje/epidemiología , Masculino , Prevalencia , Análisis de Regresión , Educación Compensatoria/economía , Factores Socioeconómicos , Encuestas y Cuestionarios
3.
Acta Anaesthesiol Scand ; 59(3): 406-7, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25557856

RESUMEN

A descriptive case report of a 22-year-old woman, scheduled for elective laparotomy who had a respiratory arrest after premedication with inj glycopyrrolate and ondansetron. Respiratory arrest is an uncommon side effect of glycopyrrolate with very few published reports. Ondansteron can also cause respiratory arrest, however is most often associated with bradycardia. This patient had tachycardia and respiratory arrest and is suggestive of glycopyrrolate-induced respiratory arrest. This case report highlights the importance of strict vigilance by the anaesthesiologist even during premedication.


Asunto(s)
Adyuvantes Anestésicos/efectos adversos , Glicopirrolato/efectos adversos , Premedicación/efectos adversos , Insuficiencia Respiratoria/inducido químicamente , Adulto , Femenino , Humanos , Taquicardia/inducido químicamente , Adulto Joven
4.
Appl Microbiol Biotechnol ; 98(2): 919-29, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23644771

RESUMEN

Tributyl phosphate (TBP) has enormous applications in the field of extraction, fuel reprocessing, as defoamers and/or plasticizers. Excessive usage of this organophosphorus compound, poses an environmental threat. The present study deals with microbial degradation of TBP using Klebsiella pneumoniae S3 isolated from the soil. Diauxic growth curve pattern explains a preferential utilization of TBP. The strain S3 was able to biotransform TBP (1,000 mg L⁻¹) to dibutyl phosphate within 48 h and showed higher tolerance towards TBP up to 17.0 g L⁻¹. Toxicity of the parent as well as degraded product was assessed using comet assay. Generation of reactive oxygen species elaborates the oxidative stress imposed upon the bacterial strain by TBP. The antioxidant defense mechanism was studied using various biomarkers namely catalase, glutathione-S-transferase, and superoxide dismutase. The present study describes a faster and eco-friendly alternative for disposal of TBP.


Asunto(s)
Klebsiella pneumoniae/metabolismo , Organofosfatos/metabolismo , Biotransformación , Ensayo Cometa , Contaminantes Ambientales/metabolismo , Contaminantes Ambientales/toxicidad , Klebsiella pneumoniae/crecimiento & desarrollo , Klebsiella pneumoniae/aislamiento & purificación , Pruebas de Mutagenicidad , Organofosfatos/toxicidad , Estrés Oxidativo , Microbiología del Suelo
5.
J Exp Bot ; 64(1): 303-15, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23162117

RESUMEN

MicroRNAs (miRNAs) constitute a novel mechanism of gene regulation affecting plant development, growth, and stress response. To study the role of miRNAs in arsenic (As) stress, microarray profiling of miRNAs was performed in Brassica juncea using a custom Phalanx Plant OneArray containing 381 unique miRNA probes representing 618 miRNAs from 22 plant species. miRNA microarray hybridization of roots exposed to As for 1h and 4h revealed that a total of 69 miRNAs belonging to 18 plant miRNA families had significantly altered expression. The As-responsive miRNAs also exhibited a time- and organ-dependent change in their expression. Putative target prediction for the miRNAs suggested that they regulate various developmental processes (e.g. miR156, miR169, and miR172), sulphur uptake, transport, and assimilation (miR395, miR838, and miR854), and hormonal biosynthesis and/or function (e.g. miR319, miR167, miR164, and miR159). Notable changes were observed in the level of auxins [indole-3-acetic acid (IAA), indole-3- butyric acid, and naphthalene acetic acid], jasmonates [jasmonic acid (JA) and methyl jasmonate], and abscisic acid. The exogenous supply of JA and IAA improved growth of plants under As stress and altered expression of miR167, miR319, and miR854, suggesting interplay of hormones and miRNAs in the regulation of As response. In conclusion, the present work demonstrates the role of miRNAs and associated mechanisms in the plant's response towards As stress.


Asunto(s)
Arsénico/toxicidad , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , MicroARNs/genética , Planta de la Mostaza/efectos de los fármacos , Planta de la Mostaza/genética , Estrés Fisiológico/genética , Ciclopentanos/farmacología , Ácidos Indolacéticos/farmacología , MicroARNs/metabolismo , Modelos Biológicos , Planta de la Mostaza/crecimiento & desarrollo , Análisis de Secuencia por Matrices de Oligonucleótidos , Especificidad de Órganos/efectos de los fármacos , Especificidad de Órganos/genética , Oxilipinas/farmacología , Reguladores del Crecimiento de las Plantas/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados , Estrés Fisiológico/efectos de los fármacos , Factores de Tiempo
6.
Mol Biol Rep ; 40(4): 2879-86, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23440514

RESUMEN

The present study analyzed the expression level of aquaporins of plasma membrane intrinsic protein (PIP) class in response to arsenite (AsIII) exposure of 100 µM from 0.5 h to 8 days in Brassica juncea. The expression levels of most of the PIPs were down-regulated during the course of AsIII exposure. This led to decrease in total water content of plants, which in turn hampered seedling growth. The level of reactive oxygen species (superoxide radicals and hydrogen peroxide), lipid peroxidation and root oxidizability increased significantly upon exposure to AsIII as compared to that of control leading to an increase in cell death. The study proposes that the down-regulation of PIPs happened presumably to regulate AsIII levels, which, however, occurred at the cost of reduced growth, disturbed water balance and induced oxidative stress.


Asunto(s)
Acuaporinas/genética , Perfilación de la Expresión Génica , Planta de la Mostaza/genética , Proteínas de Plantas/genética , Acuaporinas/metabolismo , Arsenitos/toxicidad , Muerte Celular/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas , Peróxido de Hidrógeno/metabolismo , Peroxidación de Lípido , Planta de la Mostaza/efectos de los fármacos , Planta de la Mostaza/crecimiento & desarrollo , Estrés Oxidativo , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Isoformas de Proteínas/genética , Plantones/genética , Plantones/crecimiento & desarrollo , Estrés Fisiológico/genética , Agua/química
7.
Indian J Exp Biol ; 51(12): 1055-62, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24579370

RESUMEN

Octapeptide (OP)/FSH-Receptor Binding Inhibitor-8 (FRBI-8), is a synthetic peptide corresponding to N-terminal sequence of purified fraction of Follicle Stimulating Hormone Binding-Inhibitor (FSHBI), isolated earlier from human ovarian follicular-fluid. In order to avoid the repeated drug-administration, OP-loaded, polymeric polylactide (PLA) nanoparticle formulation (NP-OP), was developed using multiple-emulsion technique. This yielded an average particle size of 120 nm with 70% encapsulation-efficiency. In vitro release profile of NP-OP showed sustained release of OP for 21 days. In vivo anti-fertility studies were conducted in marmosets. Results indicated that control animals conceived in the same cycle while two of three treated animals failed to conceive in treatment cycle. The in vivo studies thus corroborate with in vitro release of OP, demonstrating its anti-fertility activity in 66% of animals.


Asunto(s)
Proteínas Portadoras/química , Anticoncepción , Nanopartículas/química , Folículo Ovárico/química , Fragmentos de Péptidos/química , Animales , Callithrix/fisiología , Proteínas Portadoras/administración & dosificación , Femenino , Humanos , Nanopartículas/administración & dosificación , Tamaño de la Partícula , Fragmentos de Péptidos/administración & dosificación , Polímeros/administración & dosificación , Polímeros/química
8.
Phys Rev Lett ; 109(24): 246601, 2012 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-23368355

RESUMEN

Spin valves have revolutionized the field of magnetic recording and memory devices. Spin valves are generally realized in thin film heterostructures, where two ferromagnetic (FM) layers are separated by a nonmagnetic conducting layer. Here, we demonstrate spin-valve-like magnetoresistance at room temperature in a bulk ferrimagnetic material that exhibits a magnetic shape memory effect. The origin of this unexpected behavior in Mn(2)NiGa has been investigated by neutron diffraction, magnetization, and ab initio theoretical calculations. The refinement of the neutron diffraction pattern shows the presence of antisite disorder where about 13% of the Ga sites are occupied by Mn atoms. On the basis of the magnetic structure obtained from neutron diffraction and theoretical calculations, we establish that these antisite defects cause the formation of FM nanoclusters with parallel alignment of Mn spin moments in a Mn(2)NiGa bulk lattice that has antiparallel Mn spin moments. The direction of the Mn moments in the soft FM cluster reverses with the external magnetic field. This causes a rotation or tilt in the antiparallel Mn moments at the cluster-lattice interface resulting in the observed asymmetry in magnetoresistance.

9.
J Pharm Sci ; 111(2): 469-478, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34534573

RESUMEN

Nanoparticles (NPs) that can activate macrophages infected with the tuberculosis causative pathogen Mycobacterium tuberculosis, could be an effective host directed therapy for the disease. In this study, curdlan was conjugated to poly(lactic-co-glycolic acid) (PLGA) to produce immunotherapeutic NPs. Various physicochemical characterizations were used to evaluate the curdlan-PLGA copolymer and the NPs. Molecular dynamics and simulation studies were used to characterize the interaction between curdlan, on the polymer and on NPs, with the Dectin-1 macrophage receptor. NPs with varying curdlan densities were evaluated for their effects on the production of pro- and anti-inflammatory cytokines in M. tuberculosis infected RAW264.7 macrophages. The killing efficacy of the NPs against intracellular M. tuberculosis was assessed. Physicochemical characterization of the curdlan-PLGA copolymer and NPs indicated successful formation of curdlan-PLGA copolymer and NPs of varying curdlan density (0-8% w/w) had sizes between 330 and 453 nm. Modelling studies showed curdlan to have a strong affinity for Dectin-1. Cytotoxicity assays showed the NPs to be non-toxic over 72 h. The proinflammatory cytokine TNF-α was found to be significantly upregulated by the NPs. The NPs reduced intracellular M. tuberculosis burden over 72 h. These NPs are a promising host directed therapy for intracellular eradication of M. tuberculosis.


Asunto(s)
Mycobacterium tuberculosis , Nanopartículas , Portadores de Fármacos/química , Glicoles , Ácido Láctico/química , Nanopartículas/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , beta-Glucanos
10.
Int J Obstet Anesth ; 45: 133-137, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33339713

RESUMEN

BACKGROUND: Large gaps remain in our understanding of the role of social media platforms in the dissemination of medical information. This cross-sectional study quantitatively assessed the accuracy and quality of information on YouTube regarding epidural labor analgesia. METHODS: YouTube was searched on May 23, 2020 using keywords 'epidural,' 'epidural for labor,' 'epidural for pregnancy,' 'epidural experience,' and 'epidural risks,' and the top 50 viewed videos from each search were screened. Primary outcomes included the proportion of videos containing non-factual information, and video quality analyzed using the modified DISCERN (mDISCERN) score. RESULTS: Thirteen of 60 (21.7%) videos included non-factual information about epidural analgesia; these videos were viewed more than 16.5 million times (60% of total viewership of the videos analyzed). Mean (standard deviation) mDISCERN score for all included videos was 1.9 (1.3), which is below the threshold for high video-quality. Videos from medical sources (hospitals, medical practices, physicians, other medical professionals) had a higher mDISCERN score compared with videos by non-medical sources (P <0.001). Educational videos from professional societies of obstetrics or obstetric anesthesiology were not captured. CONCLUSION: YouTube is an accessible platform for medical information on epidural labor analgesia, although a significant proportion of videos studied contained non-factual information and presented low video quality. Increased efforts by reputable sources including hospitals, physicians, other medical professionals, and professional societies, to disseminate accurate information, are warranted.


Asunto(s)
Analgesia Epidural , Dolor de Parto , Medios de Comunicación Sociales , Estudios Transversales , Femenino , Humanos , Difusión de la Información , Embarazo , Grabación en Video
11.
J Exp Med ; 184(6): 2361-70, 1996 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-8976190

RESUMEN

Fas is a cell surface receptor that transduces cell death signals when cross-linked by agonist antibodies or by fas ligand. In this study, we examined the potential of fas to contribute to oligodendrocyte (OL) injury and demyelination as they occur in the human demyelinating disease multiple sclerosis (MS). Immunohistochemical study of central nervous system (CNS) tissue from MS subjects demonstrated elevated fas expression on OLs in chronic active and chronic silent MS lesions compared with OLs in control tissue from subjects with or without other neurologic diseases. In such lesions, microglia and infiltrating lymphocytes displayed intense immunoreactivity to fas ligand. In dissociated glial cell cultures prepared from human adult CNS tissue, fas expression was restricted to OLs. Fas ligation with the anti-fas monoclonal antibody M3 or with the fas-ligand induced rapid OL cell membrane lysis, assessed by LDH release and trypan blue uptake and subsequent cell death. In contrast to the activity of fas in other cellular systems, dying OLs did not exhibit evidence of apoptosis, assessed morphologically and by terminal transferase-mediated d-uridine triphosphate-biotin nick-end-labeling staining for DNA fragmentation. Other stimuli such as C2-ceramide were capable of inducing rapid apoptosis in OLs. Antibodies directed at other surface molecules expressed on OLs or the M33 non-activating anti-fas monoclonal antibody did not induce cytolysis of OLs. Our results suggest that fas-mediated signaling might contribute in a novel cytolytic manner to immune-mediated OL injury in MS.


Asunto(s)
Sistema Nervioso Central/patología , Esclerosis Múltiple/patología , Esclerosis Múltiple/fisiopatología , Oligodendroglía/patología , Receptor fas/fisiología , Adulto , Muerte Celular , Células Cultivadas , Sistema Nervioso Central/citología , Sistema Nervioso Central/fisiopatología , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Esclerosis Múltiple/inmunología , Neuroglía/citología , Neuroglía/patología , Neuroglía/fisiología , Oligodendroglía/citología , Oligodendroglía/fisiología , Valores de Referencia , Transducción de Señal , Receptor fas/biosíntesis
12.
Ann Bot ; 106(5): 663-74, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20736293

RESUMEN

BACKGROUND AND AIMS: Abiotic stresses including salinity are the major constraints to crop production. In this regard, the use of thiourea (TU) in imparting salinity-stress tolerance to Indian mustard (Brassica juncea) has been demonstrated earlier. To gain an insight into the mechanism of TU action, various molecular and biochemical studies were conducted. METHODS: Microarray analysis was performed in seeds subjected to distilled water (control), 1 m NaCl, 1 m NaCl + 6·5 mm TU and 6·5 mm TU alone for 1 h. Real-time PCR validation of selected genes and biochemical studies were conducted under similar treatments at 1 h and 6 h. KEY RESULTS: The microarray analysis revealed a differential expression profile of 33 genes in NaCl- and NaCl + TU-treated seeds, most of which are established markers of stress tolerance. The temporal regulation of eight selected genes by real-time PCR indicated their early and co-ordinated induction at 1 h in NaCl + TU only. Besides, NaCl + TU-treated seeds also maintained a higher level of abscisic acid, reduced to oxidized glutathione (GSH : GSSG) ratio and activities of catalase, phenylalanine ammonia lyase and glutathione-S-transferases, as compared with that of NaCl treatment. The addition of LaCl(3) (a specific calcium-channel blocker) restricted the responses of TU both at molecular and biochemical level suggesting the possible involvement of a cytosolic calcium burst in the TU-mediated response. The TU-alone treatment was comparable to that of the control; however, it reduced the expression of some transcription factors and heat-shock proteins presumably due to the stabilization of the corresponding proteins. CONCLUSIONS: The TU treatment co-ordinately regulates different signalling and effector mechanisms at an early stage to alleviate stress even under a high degree of salinity. This also indicates the potential of TU to be used as an effective bioregulator to impart salinity tolerance under field conditions.


Asunto(s)
Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Planta de la Mostaza/efectos de los fármacos , Planta de la Mostaza/metabolismo , Transducción de Señal , Cloruro de Sodio/farmacología , Estrés Fisiológico , Tiourea/farmacología , Ácido Abscísico/farmacología , Catalasa/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Glutatión/metabolismo , Disulfuro de Glutatión/metabolismo , Glutatión Transferasa/metabolismo , Planta de la Mostaza/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Fenilanina Amoníaco-Liasa/metabolismo , Proteínas de Plantas/metabolismo , Reacción en Cadena de la Polimerasa , Salinidad , Semillas/efectos de los fármacos , Semillas/genética , Semillas/metabolismo
13.
Eur Phys J E Soft Matter ; 31(4): 393-402, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20480963

RESUMEN

Morphological transformation during evaporation-induced self-assembly of a mixed colloidal suspension in micrometric droplets has been investigated. It has been demonstrated that a buckling-driven shape transition of drying droplets of mixed colloidal suspension takes place during evaporation-induced self-assembly. Further, it is also shown that the distortion modulations get significantly amplified with enhancement in volume fraction of anisotropic soft colloidal component of the mixed colloids. It has been argued that the reduction in elastic modulus of formed shell, at the boundary of a drying droplet, and the anisotropic nature of one of the colloidal components facilitate the deformation process. Hierarchical structures of these assembled colloidal grains have been probed using electron microscopy and scattering techniques.


Asunto(s)
Coloides/química , Desecación , Suspensiones/química , Anisotropía , Módulo de Elasticidad , Escherichia coli/química , Escherichia coli/ultraestructura , Luz , Microscopía Electrónica de Rastreo , Difracción de Neutrones , Dispersión del Ángulo Pequeño , Dióxido de Silicio/química , Volatilización
14.
Can J Microbiol ; 56(10): 822-30, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20962905

RESUMEN

Phosphate-solubilizing bacteria (PSBs) were isolated from different plant rhizosphere soils of various agroecological regions of India. These isolates showed synthesis of pyrroloquinoline quinone (PQQ), production of gluconic acid, and release of phosphorus from insoluble tricalcium phosphate. The bacterial isolates synthesizing PQQ also showed higher tolerance to ultraviolet C radiation and mitomycin C as compared to Escherichia coli but were less tolerant than Deinococcus radiodurans. Unlike E. coli, PSB isolates showed higher tolerance to DNA damage when grown in the absence of inorganic phosphate. Higher tolerance to ultraviolet C radiation and oxidative stress in these PSBs grown under PQQ synthesis inducible conditions, namely phosphate starvation, might suggest the possible additional role of this redox cofactor in the survival of these isolates under extreme abiotic stress conditions.


Asunto(s)
Burkholderia cepacia/fisiología , Daño del ADN , Enterobacteriaceae/fisiología , Cofactor PQQ/biosíntesis , Fosfatos/metabolismo , Pseudomonas oleovorans/fisiología , Microbiología del Suelo , Burkholderia cepacia/clasificación , Burkholderia cepacia/aislamiento & purificación , Fosfatos de Calcio/metabolismo , Catalasa , Enterobacter/clasificación , Enterobacter/genética , Enterobacter/aislamiento & purificación , Enterobacter/fisiología , Enterobacteriaceae/clasificación , Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Gluconatos/metabolismo , India , Mitomicina/farmacología , Estrés Oxidativo , Pantoea/clasificación , Pantoea/genética , Pantoea/aislamiento & purificación , Pantoea/fisiología , Reacción en Cadena de la Polimerasa , Proteus mirabilis/clasificación , Proteus mirabilis/genética , Proteus mirabilis/aislamiento & purificación , Proteus mirabilis/fisiología , Pseudomonas oleovorans/clasificación , Pseudomonas oleovorans/genética , Pseudomonas oleovorans/aislamiento & purificación , Tolerancia a Radiación , Rizosfera , Rayos Ultravioleta
15.
Ecotoxicol Environ Saf ; 73(6): 1314-22, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20079533

RESUMEN

In the present study, Hydrilla verticillata plants were exposed to arsenate (AsV; 50 microM) and arsenite (AsIII; 5 microM) under variable S supply: deficient (2 microM S, -S), normal (1 mM S, +S) and excess (2 mM S, +HS). Arsenic accumulation (microg g(-1) dw) in +HS plants was about 2-fold higher upon exposure to both AsV (30) and AsIII (50) than that observed in +S (12 & 24) and -S (14 & 26) plants. Despite lower As accumulation, -S plants experienced the maximum oxidative stress owing to an inadequate response of enzymatic and molecular antioxidants and significant decline in total thiols and the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG). By contrast +HS plants had significant increase in total thiols and an improved redox status, did not demonstrate any negative impact to antioxidants except catalase and hence experienced the least increase in oxidative stress parameters. In conclusion, an increase in S supply to plants may improve their accumulation capacity for As through enhanced tolerance caused by a positive effect on thiol metabolism and antioxidant status of the plants.


Asunto(s)
Antioxidantes/metabolismo , Arsénico/toxicidad , Hydrocharitaceae/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Sulfatos/farmacología , Arsénico/farmacocinética , Catalasa/metabolismo , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Glutatión Peroxidasa/metabolismo , Hydrocharitaceae/enzimología , Hydrocharitaceae/crecimiento & desarrollo , Hydrocharitaceae/metabolismo , Contaminantes del Suelo/farmacocinética , Espectrometría de Fluorescencia , Superóxido Dismutasa/metabolismo
16.
Kathmandu Univ Med J (KUMJ) ; 8(32): 420-2, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-22610773

RESUMEN

Metastasis of bronchogenic carcinoma to the chest wall and axillary lymphnodes is a rare occurrence. This study reports the case of a patient presenting with chest wall swelling as initial symptom which on evaluation was found to be a lymphnode metastasis. The patient also had axillary lymphnode metastasis on the same side as the chest swelling with a contralateral pleural effusion. Here, we discuss the pathways and possible mechanisms of contra lateral axillary and chest wall lymphnode involvement without ispilateral nodal involvement in bronchogenic carcinoma.


Asunto(s)
Carcinoma Broncogénico/secundario , Neoplasias Pulmonares/patología , Ganglios Linfáticos/patología , Axila , Carcinoma Broncogénico/diagnóstico , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Pared Torácica
17.
J Perinatol ; 40(9): 1433-1440, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-31907396

RESUMEN

BACKGROUND: Antibiotics are the most prescribed medication in the neonatal intensive care unit (NICU) and there is marked variation in their use. While they are vital for treatment of infections, they put infants at risk for infections with drug resistant organisms, alteration in their microbiome and several other morbidities. Specific guidelines for neonates are often lacking and our NICU is not compliant with late onset sepsis (LOS) guidelines. OBJECTIVE: By January 2019, there will be >75% compliance with our LOS bundle for any infant admitted to Tampa General Hospital's (TGH) NICU undergoing a LOS evaluation at >72 h of life. The bundle includes documented reason for LOS evaluation, appropriate initial antibiotic selection, appropriate initial evaluation considered, and appropriate de-escalation of antibiotics. STUDY DESIGN: The project was implemented in the NICU at TGH, the academic medical center affiliated with the University of South Florida in Tampa, FL. The multidisciplinary antimicrobial stewardship (ASP) team responsible for the project consists of a neonatology attending, three neonatology fellows, a pediatric infectious disease attending, and two NICU pharmacists. The project was started in January 2017 and all data were collected prospectively. We implemented multiple Plan-Do-Study-Act cycles in a stepwise manner; outcome measures included compliance with the LOS bundle and ASP team recommendations. Our process measures were the documented reason for sepsis evaluation, appropriate initial evaluation considered, appropriate antibiotic selection and appropriate antibiotic de-escalation. Patient length of stay was the balancing measure studied. RESULTS: During this 20-month initiative, there were 232 infants who underwent LOS evaluation and there were 98 true positive cultures from blood (28%), urine (35%), and cerebrospinal fluid (3%). Commonly documented rationales for treatment of culture negative sepsis were clinical pneumonia (38%) and necrotizing enterocolitis (38%). Common indications for LOS evaluations were increased respiratory support (51%) and abdominal distension (17%). There was improvement in appropriate initial antibiotic selection (70% vs. 94%); appropriate consideration of initial evaluation (63% vs. 94%, respectively); appropriate de-escalation of antibiotics (86% vs. 100%, respectively) and increase in LOS bundle compliance (44% vs. 87%, respectively). The overall antibiotic utilization rate and length of treatment did not change significantly. CONCLUSIONS: Developing and engaging a NICU ASP team improves compliance with late onset sepsis guidelines through the implementation of a LOS bundle of care.


Asunto(s)
Programas de Optimización del Uso de los Antimicrobianos , Sepsis , Antibacterianos/uso terapéutico , Niño , Humanos , Lactante , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Mejoramiento de la Calidad , Sepsis/diagnóstico , Sepsis/tratamiento farmacológico
18.
ACS Nano ; 14(12): 17554-17564, 2020 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-33236903

RESUMEN

The coupling of real and momentum space is utilized to tailor electronic properties of the collinear metallic antiferromagnet Mn2Au by aligning the real space Néel vector indicating the direction of the staggered magnetization. Pulsed magnetic fields of 60 T were used to orient the sublattice magnetizations of capped epitaxial Mn2Au(001) thin films perpendicular to the applied field direction by a spin-flop transition. The electronic structure and its corresponding changes were investigated by angular-resolved photoemission spectroscopy with photon energies in the vacuum-ultraviolet, soft, and hard X-ray range. The results reveal an energetic rearrangement of conduction electrons propagating perpendicular to the Néel vector. They confirm previous predictions on the origin of the Néel spin-orbit torque and anisotropic magnetoresistance in Mn2Au and reflect the combined antiferromagnetic and spin-orbit interaction in this compound leading to inversion symmetry breaking.

19.
J Exp Bot ; 60(12): 3419-31, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19528528

RESUMEN

The mechanisms of perception of arsenic (As)-induced stress and ensuing tolerance in plants remain unresolved. To obtain an insight into these mechanisms, biochemical and transcriptional profiling of two contrasting genotypes of Brassica juncea was performed. After screening 14 varieties for As tolerance, one tolerant (TPM-1) and one sensitive (TM-4) variety were selected and exposed to arsenate [As(V)] and arsenite [As(III)] for 7 d and 15 d for biochemical analyses. The tolerant variety (TPM-1) demonstrated higher accumulation of As upon exposure to both 500 microM As(V) and 250 microM As(III) [49 microg g(-1) and 37 microg g(-1) dry weight (dw) after 15 d] as well as a better response of thiol metabolism as compared with the responses observed in the sensitive variety (TM-4). Transcriptional profiling of selected genes that are known to be responsive to sulphur depletion and/or metal(loid) stress was conducted in 15-d-old seedlings after 3 h and 6 h exposure to 250 microM As(III). The results showed an up-regulation of sulphate transporters and auxin and jasmonate biosynthesis pathway genes, whereas there was a down-regulation of ethylene biosynthesis and cytokinin-responsive genes in TPM-1 within 6 h of exposure to As(III). This suggested that perception of As-induced stress was presumably mediated through an integrated modulation in hormonal functioning that led to both short- and long-term adaptations to combat the stress. Such a coordinated response of hormones was not seen in the sensitive variety. In conclusion, an early perception of As-induced stress followed by coordinated responses of various pathways was responsible for As tolerance in TPM-1.


Asunto(s)
Arsénico/farmacología , Brassica/efectos de los fármacos , Brassica/fisiología , Perfilación de la Expresión Génica , Arseniatos/farmacología , Arsénico/metabolismo , Arsenitos/farmacología , Brassica/genética , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estrés Fisiológico
20.
Science ; 242(4875): 91-3, 1988 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-3262922

RESUMEN

Many adhesive interactions are mediated by Arg-Gly-Asp (RGD) sequences within adhesive proteins. Such RGD sequences are frequently recognized by structurally related heterodimers that are members of the integrin family of adhesion receptors. A region was found in the platelet RGD receptor, gpIIb/IIIa, to which an RGD peptide becomes chemically cross-linked. This region corresponds to residues 109 to 171 of gpIIIa. This segment is conserved among the beta subunits of the integrins (76 percent identity of sequence), indicating that it may play a role in the adhesive functions of this family of receptors.


Asunto(s)
Glicoproteínas de Membrana/metabolismo , Receptores Inmunológicos/metabolismo , Receptores de Péptidos , Secuencia de Aminoácidos , Sitios de Unión , Plaquetas/inmunología , Humanos , Integrinas , Glicoproteínas de Membrana/genética , Datos de Secuencia Molecular , Glicoproteínas de Membrana Plaquetaria/genética , Glicoproteínas de Membrana Plaquetaria/metabolismo , Unión Proteica
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