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1.
Commun Biol ; 5(1): 1411, 2022 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-36564617

RESUMEN

Traditionally, patient travel history has been used to distinguish imported from autochthonous malaria cases, but the dormant liver stages of Plasmodium vivax confound this approach. Molecular tools offer an alternative method to identify, and map imported cases. Using machine learning approaches incorporating hierarchical fixation index and decision tree analyses applied to 799 P. vivax genomes from 21 countries, we identified 33-SNP, 50-SNP and 55-SNP barcodes (GEO33, GEO50 and GEO55), with high capacity to predict the infection's country of origin. The Matthews correlation coefficient (MCC) for an existing, commonly applied 38-SNP barcode (BR38) exceeded 0.80 in 62% countries. The GEO panels outperformed BR38, with median MCCs > 0.80 in 90% countries at GEO33, and 95% at GEO50 and GEO55. An online, open-access, likelihood-based classifier framework was established to support data analysis (vivaxGEN-geo). The SNP selection and classifier methods can be readily amended for other use cases to support malaria control programs.


Asunto(s)
Malaria Vivax , Malaria , Humanos , Malaria Vivax/diagnóstico , Malaria Vivax/genética , Funciones de Verosimilitud , Plasmodium vivax/genética , Internet
2.
Plants (Basel) ; 11(21)2022 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-36365282

RESUMEN

Mutations in the Betaine aldehyde dehydrogenase 2 (OsBadh2) gene resulted in aroma, which is a highly preferred grain quality attribute in rice. However, research on naturally occurring aromatic rice has revealed ambiguity and controversy regarding aroma emission, stress tolerance, and response to salinity. In this study, mutant lines of two non-aromatic varieties, Huaidao#5 (WT_HD) and Jiahua#1 (WT_JH), were generated by targeted mutagenesis of OsBadh2 using CRISPR/Cas9 technology. The mutant lines of both varieties became aromatic; however, WT_HD mutants exhibited an improved tolerance, while those of WT_JH showed a reduced tolerance to salt stress. To gain insight into the molecular mechanism leading to the opposite effects, comparative analyses of the physiological activities and expressions of aroma- and salinity-related genes were investigated. The WT_HD mutants had a lower mean increment rate of malondialdehyde, superoxide dismutase, glutamate, and proline content, with a higher mean increment rate of γ-aminobutyric acid, hydrogen peroxide, and catalase than the WT_JH mutants. Fluctuations were also detected in the salinity-related gene expression. Thus, the response mechanism of OsBadh2 mutants is complicated where the genetic makeup of the rice variety and interactions of several genes are involved, which requires more in-depth research to explore the possibility of producing highly tolerant aromatic rice genotypes.

3.
Mol Nutr Food Res ; 66(4): e2100576, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34779572

RESUMEN

SCOPE: Certain food emulsifiers may interfere with gut barrier function in ways correlating to increased exposure to allergens. Understanding the consequences of interactions between these food ingredients and the intestinal epithelium is important for evaluating allergen dose exposure characteristics. METHODS AND RESULTS: This study challenged Caco-2 cell monolayers, an in vitro model of human intestinal epithelial tight junctions with synthetic polysorbate-80 or natural lecithin alone, or in combination with known allergens (egg proteins: ovalbumin, ovomucoid, and ovotransferrin; and a synthetic form of galactose-alpha-1,3-galactose [alpha-gal], an allergen of increasing concern). For most doses of individual emulsifiers and allergens, >90% cell viability and <15% cytotoxicity are observed; however, toxicity increased at a 0.5% concentration of emulsifiers. At low cytotoxic concentration (0.2%), only polysorbate-80 treatment reduced monolayer integrity (≈20%) with increased lucifer yellow passage. Dose-related differences in expression of tight junction-associated genes and occludin protein are observed with emulsifier treatments. The transport of all tested allergens across the cell monolayers, excluding ovotransferrin, nearly doubled in the presence of 0.2% polysorbate-80 compared to lecithin and untreated control. CONCLUSION: By modulating paracellular permeability, polysorbate-80 may enhance absorption of allergens in a size-dependent manner.


Asunto(s)
Emulsionantes , Mucosa Intestinal , Uniones Estrechas , Alérgenos/metabolismo , Células CACO-2 , Emulsionantes/efectos adversos , Emulsionantes/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Ocludina/genética , Ocludina/metabolismo , Permeabilidad
4.
Front Immunol ; 12: 672353, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33995413

RESUMEN

Invasive foodborne Listeria monocytogenes infection causes gastroenteritis, septicemia, meningitis, and chorioamnionitis, and is associated with high case-fatality rates in the elderly. It is unclear how aging alters gut microbiota, increases risk of listeriosis, and causes dysbiosis post-infection. We used a geriatric murine model of listeriosis as human surrogate of listeriosis for aging individuals to study the effect of aging and L. monocytogenes infection. Aging and listeriosis-induced perturbation of gut microbiota and disease severity were compared between young-adult and old mice. Young-adult and old mice were dosed intragastrically with L. monocytogenes. Fecal pellets were collected pre- and post-infection for microbiome analysis. Infected old mice had higher Listeria colonization in liver, spleen, and feces. Metagenomics analyses of fecal DNA-sequences showed increase in α-diversity as mice aged, and infection reduced its diversity. The relative abundance of major bacterial phylum like, Bacteroidetes and Firmicutes remained stable over aging or infection, while the Verrucomicrobia phylum was significantly reduced only in infected old mice. Old mice showed a marked reduction in Clostridaiceae and Lactobacillaceae bacteria even before infection when compared to uninfected young-adult mice. L. monocytogenes infection increased the abundance of Porphyromonadaceae and Prevotellaceae in young-adult mice, while members of the Ruminococcaceae and Lachnospiraceae family were significantly increased in old mice. The abundance of the genera Blautia and Alistipes were significantly reduced post-infection in young-adult and in old mice as compared to their uninfected counterparts. Butyrate producing, immune-modulating bacterial species, like Pseudoflavonifractor and Faecalibacterium were significantly increased only in old infected mice, correlating with increased intestinal inflammatory mRNA up-regulation from old mice tissue. Histologic analyses of gastric tissues showed extensive lesions in the Listeria-infected old mice, more so in the non-glandular region and fundus than in the pylorus. Commensal species like Lactobacillus, Clostridiales, and Akkermansia were only abundant in infected young-adult mice but their abundance diminished in the infected old mice. Listeriosis in old mice enhances the abundance of butyrate-producing inflammatory members of the Ruminococcaceae/Lachnospiraceae bacteria while reducing/eliminating beneficial commensals in the gut. Results of this study indicate that, aging may affect the composition of gut microbiota and increase the risk of invasive L. monocytogenes infection.


Asunto(s)
Envejecimiento/fisiología , Disbiosis/microbiología , Microbioma Gastrointestinal/fisiología , Listeriosis/microbiología , Animales , Femenino , Listeria monocytogenes , Ratones , Ratones Endogámicos C57BL , Factores de Riesgo
5.
Curr Org Synth ; 18(7): 685-710, 2021 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-33645484

RESUMEN

Heterocycles are the main structural motif of DNA and RNA and play a crucial role in various chemical reactions of metabolisms. Therefore, heterocyclic compounds show good physiological and pharmacological properties. Coumarin and pyrazole scaffolds are present in many commercial drug molecules and natural products. This review overviews the progress made in the synthesis and functionalization of the coumarin- pyrazole hybrid heterocycle. It also includes discussion on the possible reactive sites of heterocycles, functionalization, and mechanistic pathways to incorporate pyrazole pharmacophore unit in synthesis. Several synthesis and biological studies reveal that the combination of the coumarin-pyrazole moiety is a prominent structural motif to find lead compounds in drug discovery.


Asunto(s)
Cumarinas , Pirazoles , Descubrimiento de Drogas
6.
Anticancer Agents Med Chem ; 20(4): 464-475, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31763968

RESUMEN

BACKGROUND: Cancer is one of the leading causes of mortality globally. To cope with cancer, it is necessary to develop anticancer drugs. Bioactive natural products, i.e. diarylheptanoids, have gained significant attention of researchers owing to their intriguing structures and potent biological activities. In this article, considering the development of anticancer drugs with enhanced selectivity towards cancerous cells, a series of Cyclic Diarylheptanoids (CDHs) are designed, synthesized and evaluated their biological activity. OBJECTIVE: To establish an easy route for the synthesis of diarylheptanoids, and evaluate their antiproliferative, and topoisomerase-I & -IIα inhibitory activities, for developing potential anticancer drugs among CDHs. METHODS: Diarylheptanoids were synthesized from reported linear diarylheptanoids using the classical Ullmann reaction. Antibacterial activity was evaluated by the filter paper disc diffusion method. Cell viability was assessed by measuring mitochondrial dehydrogenase activity with a Cell Counting Kit (CCK-8). Topoisomerases I and II (topo-I and -IIα) inhibitory activity was measured by the assessment of relaxation of supercoiled pBR322 plasmid DNA. IFD protocol of Schrodinger Maestro v11.1 was used to characterize the binding pattern of studied compounds with the ATPase domain of the human topo-IIα. RESULTS: The synthesized CDHs were evaluated for their biological activities (antibacterial, antiproliferative, and topoisomerase-I & -IIα inhibitory activities, respectively). Leading to obtain a series of anticancer agents with the least inhibitory activities against different microbes, improving their selectivity for cancer cells. In brief, most of the synthesized CDHs had excellent antiproliferative activity against T47D (human breast cancer cell line). Pterocarine possessed the strongest activity (2i; IC50 = 0.63µM) against T47D. The cyclic diarylheptanoid 2b induced 30% inhibition of topoisomerase-IIα activity at 100µM compared with the reference of etoposide, which induced 72% inhibition. Among the tested compounds, galeon (2h) displayed very low activity against four bacterial strains. Compounds 2b, 2h, and 2i formed hydrogen bonds with Thr215, Asn91, Asn120, Ala167, Lys168 and Ile141 residues, which are important for binding of ligand compound to the ATPase binding site of topoisomerase IIα by acting as ATP competitive molecule validated by docking study. In silico Absorption, Distribution, Metabolism and Excretion (ADME) analysis revealed the predicted ADME parameters of the studied compounds which showed recommended values. CONCLUSION: A series of CDHs were synthesized and evaluated for their antibacterial, antiproliferative, and topo-I & -IIα inhibitory activities. SARs study, molecular docking study and in silico ADME analysis were conducted. Five compounds exhibited excellent and selective antiproliferative activity against the human breast cancer cell line (T47D). Among them, a compound 2h showed topo-IIα activity by 30% at 100µM, which represented a moderate intensity of inhibition compared with etoposide. Three of them formed hydrogen bonds with Thr215, Asn91, Asn120, and Ala167 residues, which are considered as crucial residues for binding to the ATPase domain of topoisomerase IIα. According to in silico drug-likeness property analysis, three compounds are expected to show superiority over etoposide in case of absorption, distribution, metabolism and excretion.


Asunto(s)
Antineoplásicos/farmacología , Diarilheptanoides/farmacología , Inhibidores de Topoisomerasa/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ciclización , ADN-Topoisomerasas de Tipo I/metabolismo , ADN-Topoisomerasas de Tipo II/metabolismo , Diarilheptanoides/síntesis química , Diarilheptanoides/química , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Simulación del Acoplamiento Molecular , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Inhibidores de Topoisomerasa/síntesis química , Inhibidores de Topoisomerasa/química
7.
J Food Sci Technol ; 56(11): 5063-5073, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31741531

RESUMEN

This study aimed to investigate the suitability of refined bleached deodorized palm olein oil (RBD POO) and Macadamia integrifolia oil (MO) blend as deep-fat frying substitute. Oxidative and hydrolytic stability of MO, POO and blends during 15 days of storage under accelerated oxidation condition (65 °C ± 1) studied by assessing free fatty acids (FFA), peroxide (PV), anisidine (AV) and TOTOX (TV) values. Blends formulated with POO: MO at 100:0, 75:25, 50:50, 25:75 and 0:100. Blending significantly affected the fatty acid profile, smoke point, FFA, PV, AV and TV of all samples (p < 0.05). Both independent variables (storage time and type of oil) and their interaction had significant effect on FFA, PV, AV and TV (p < 0.05). On day 15, the highest and the lowest FFA observed for MO and POO, respectively. The significant difference between FFA of MO and POO before incubation and day 15th was due to role of refining process in elimination of initial FFAs from POO. Results of PV, AV and TV showed that the highest and least changes were presented by POO and MO, respectively. Oil blends containing higher proportions of MO with a great percentage of monounsaturated and less polyunsaturated fats were more stable against oxidation. Also, presence of antioxidants played significant role against MO oxidation. From this research, blending POO with MO improved induction period of the blends and inhibited primary and secondary oxidation products formation. Blend 25:75 met the qualitative and nutritional criteria and suggested for formulation of a functional oxidative stable frying medium.

8.
Sensors (Basel) ; 19(17)2019 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-31466261

RESUMEN

Lung cancer is one of the major causes of cancer-related deaths due to its aggressive nature and delayed detections at advanced stages. Early detection of lung cancer is very important for the survival of an individual, and is a significant challenging problem. Generally, chest radiographs (X-ray) and computed tomography (CT) scans are used initially for the diagnosis of the malignant nodules; however, the possible existence of benign nodules leads to erroneous decisions. At early stages, the benign and the malignant nodules show very close resemblance to each other. In this paper, a novel deep learning-based model with multiple strategies is proposed for the precise diagnosis of the malignant nodules. Due to the recent achievements of deep convolutional neural networks (CNN) in image analysis, we have used two deep three-dimensional (3D) customized mixed link network (CMixNet) architectures for lung nodule detection and classification, respectively. Nodule detections were performed through faster R-CNN on efficiently-learned features from CMixNet and U-Net like encoder-decoder architecture. Classification of the nodules was performed through a gradient boosting machine (GBM) on the learned features from the designed 3D CMixNet structure. To reduce false positives and misdiagnosis results due to different types of errors, the final decision was performed in connection with physiological symptoms and clinical biomarkers. With the advent of the internet of things (IoT) and electro-medical technology, wireless body area networks (WBANs) provide continuous monitoring of patients, which helps in diagnosis of chronic diseases-especially metastatic cancers. The deep learning model for nodules' detection and classification, combined with clinical factors, helps in the reduction of misdiagnosis and false positive (FP) results in early-stage lung cancer diagnosis. The proposed system was evaluated on LIDC-IDRI datasets in the form of sensitivity (94%) and specificity (91%), and better results were obatined compared to the existing methods.


Asunto(s)
Diagnóstico por Computador , Neoplasias Pulmonares/diagnóstico , Neoplasias/diagnóstico , Tecnología Inalámbrica , Bases de Datos Factuales , Aprendizaje Profundo , Detección Precoz del Cáncer , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Internet de las Cosas , Pulmón/diagnóstico por imagen , Pulmón/fisiología , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Neoplasias/diagnóstico por imagen , Neoplasias/patología , Redes Neurales de la Computación , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X
9.
Microb Pathog ; 99: 236-246, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27574777

RESUMEN

Foodborne Listeria monocytogenes (LM) is a cause of serious illness and death in the US. The case-fatality rate of invasive LM infection in the elderly population is >50%. The goal of this study is to establish a murine model of oral LM infection that can be used as a surrogate for human foodborne listeriosis in the geriatric population. Adult C57BL/6 (wild-type, WT) and adult or old IL17R-KO (knock-out) mice were gavaged with a murinized LM strain (Lmo-InlAm) and monitored for body-weight loss and survivability. Tissues were collected and assayed for bacterial burden, histology, and cytokine responses. When compared to WT mice, adult IL17R-KO mice are more susceptible to LM infection and showed increased LM burden and tissue pathology and a higher mortality rate. Older LM-infected KO-mice lost significantly (p < 0.02, ANOVA) more body-weight and had a higher bacterial burden in the liver (p = 0.03) and spleen as compared to adult mice. Uninfected, aged KO-mice showed a higher baseline pro-inflammatory response when compared to uninfected adult-KO mice. After infection, the pro-inflammatory cytokine, IFN-γ, mRNA in the liver was higher in the adult mice as compared to the old mice. The anti-inflammatory cytokine, IL-10, mRNA and regulatory T-cells (CD4+CD25+h or CD4+Foxp3+) cells in the aged mice increased significantly after infection as compared to adult mice. Expression of the T-cell activation marker, CD25 (IL-2Rα) in the aged mice did not increase significantly over baseline. These data suggest that aged IL17R-KO mice can be used as an in vivo model to study oral listeriosis and that aged mice are more susceptible to LM infection due to dysregulation of pro- and anti-inflammatory responses compared to adult mice, resulting in a protracted clearance of the infection.


Asunto(s)
Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Listeria monocytogenes/crecimiento & desarrollo , Listeriosis/microbiología , Listeriosis/patología , Receptores de Interleucina-17/deficiencia , Administración Oral , Factores de Edad , Estructuras Animales/microbiología , Estructuras Animales/patología , Animales , Carga Bacteriana , Peso Corporal , Citocinas/análisis , Histocitoquímica , Inmunofenotipificación , Subunidad alfa del Receptor de Interleucina-2/análisis , Ratones Endogámicos C57BL , Ratones Noqueados , Análisis de Supervivencia , Linfocitos T Reguladores/inmunología
10.
Matern Child Nutr ; 11 Suppl 4: 120-31, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23800099

RESUMEN

Food fortification is a cost-effective and sustainable strategy to prevent or correct micronutrient deficiencies. A double-blind cluster (bari) randomised controlled trial was conducted in a rural community in Bangladesh to evaluate the impact of consumption of chapatti made of micronutrient-fortified wheat flour for 6 months by school-aged children on their vitamin A, haemoglobin and iron status. A total of 43 baris (group of households) were randomly selected. The baris were randomly assigned to either intervention or control group. The intervention group received wheat flour fortified with added micronutrients (including 66 mg hydrogen-reduced elemental iron and 3030 µg retinol equivalent as retinyl palmitate per kilogram of flour), while the control group received wheat flour without added micronutrients. A total of 352 children were enrolled in the trial, 203 in the intervention group and 149 in the control group. Analyses were carried out on children who completed the study (191 in the intervention group and 143 in the control group). Micronutrient-fortified wheat flour chapatti significantly increased serum retinol concentration at 6 months by 0.12 µmol L(-1) [95% confidence interval (CI): 0.06, 0.19; P < 0.01]. The odds of vitamin A deficiency was significantly lower for children in the intervention group at 3 months [odds ratio (OR) = 0.26; 95% confidence interval (CI): 0.07, 0.89; P < 0.05] and 6 months (OR = 0.21; 95% CI: 0.06, 0.68; P < 0.01). No demonstrable effect of fortified chapatti consumption on iron status, haemoglobin levels or anaemia was observed. Consumption of fortified chapattis demonstrated a significant improvement in the vitamin A status, but not in iron, haemoglobin or anaemia status.


Asunto(s)
Harina/análisis , Alimentos Fortificados , Hierro de la Dieta/sangre , Micronutrientes/administración & dosificación , Triticum/química , Vitamina A/sangre , Adolescente , Anemia Ferropénica/dietoterapia , Bangladesh , Índice de Masa Corporal , Niño , Análisis por Conglomerados , Dieta , Método Doble Ciego , Femenino , Ferritinas/sangre , Hemoglobinas/metabolismo , Humanos , Hierro de la Dieta/administración & dosificación , Masculino , Micronutrientes/análisis , Estado Nutricional , Población Rural , Vitamina A/administración & dosificación , Deficiencia de Vitamina A/dietoterapia
11.
Sensors (Basel) ; 14(8): 13437-75, 2014 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-25061840

RESUMEN

In this paper, we review the recent trends and advancements on correlation-based pattern recognition and tracking in forward-looking infrared (FLIR) imagery. In particular, we discuss matched filter-based correlation techniques for target detection and tracking which are widely used for various real time applications. We analyze and present test results involving recently reported matched filters such as the maximum average correlation height (MACH) filter and its variants, and distance classifier correlation filter (DCCF) and its variants. Test results are presented for both single/multiple target detection and tracking using various real-life FLIR image sequences.


Asunto(s)
Reconocimiento de Normas Patrones Automatizadas/métodos , Espectrofotometría Infrarroja/instrumentación , Espectrofotometría Infrarroja/métodos , Inteligencia Artificial , Interpretación de Imagen Asistida por Computador/instrumentación , Interpretación de Imagen Asistida por Computador/métodos , Técnica de Sustracción/instrumentación
12.
Indian J Ophthalmol ; 62(3): 344-6, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23619491

RESUMEN

Cholesterol granuloma is a rare, well-defined lesion of the orbit. In the orbit, diploe of the frontal bone is involved almost exclusively. We report an atypical case of cholesterol granuloma involving superomedial quadrant of orbit. A 42-year-old male presented with progressive, painless, proptosis with infero-temporal displacement of left eye. A large mass was felt beneath the bony orbital margin in the superomedial quadrant of the left orbit. Computerized tomography (CT) scan revealed an extraconal superomedial, heterogeneous enhancing mass which was isodense with brain and pushing the globe inferolaterally and anteriorly. Excision biopsy of the tumor revealed the typical features of a cholesterol granuloma without any epithelial elements. Cholesterol granuloma of the orbit is a rare entity, but it can be diagnosed and differentiated from other lesions of the superior orbit by its characteristic clinical, radiological and histopathological features. An appropriate intervention in time carries a good prognosis with almost no recurrence.


Asunto(s)
Colesterol , Granuloma de Cuerpo Extraño/diagnóstico , Enfermedades Orbitales/diagnóstico , Adulto , Diagnóstico Diferencial , Granuloma de Cuerpo Extraño/cirugía , Humanos , Masculino , Procedimientos Quirúrgicos Oftalmológicos/métodos , Enfermedades Orbitales/cirugía , Fotomicrografía , Tomografía Computarizada por Rayos X
13.
Sensors (Basel) ; 12(10): 13441-57, 2012 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-23202003

RESUMEN

In this paper, a double-random phase-encoding technique-based text encryption and hiding method is proposed. First, the secret text is transformed into a 2-dimensional array and the higher bits of the elements in the transformed array are used to store the bit stream of the secret text, while the lower bits are filled with specific values. Then, the transformed array is encoded with double-random phase-encoding technique. Finally, the encoded array is superimposed on an expanded host image to obtain the image embedded with hidden data. The performance of the proposed technique, including the hiding capacity, the recovery accuracy of the secret text, and the quality of the image embedded with hidden data, is tested via analytical modeling and test data stream. Experimental results show that the secret text can be recovered either accurately or almost accurately, while maintaining the quality of the host image embedded with hidden data by properly selecting the method of transforming the secret text into an array and the superimposition coefficient. By using optical information processing techniques, the proposed method has been found to significantly improve the security of text information transmission, while ensuring hiding capacity at a prescribed level.

14.
Inorg Chem ; 51(21): 11241-50, 2012 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-22458446

RESUMEN

High nuclearity [Mn(10)M(2)] clusters have been achieved through a self-assembly approach where multiple coordinating functional groups are incorporated into one ligand. When the hydrazone group appended with an oxime function as a reactive intermediate is used, the attachment of a vanillin subunit creates a ligand (L4) with three coordinating groups, which in their own right lead to cluster assemblies. The trifunctional ligand L4 produces a series of self-assembled, mixed oxidation state (Mn(II)/Mn(III)) Mn(10)M(2) based clusters with an overall linear structure comprising two connected pentanuclear Mn(5) halves, which bind alkali metal cations (M = Li, Na, K, Rb, Cs) and H(3)O(+) in the vanillin (O(6)) end pockets, created by the assembly of three ligands around each Mn(5) subunit. Antiferromagnetic exchange dominates the spin coupling in the Mn(10) complexes, and surface studies on highly oriented pyrolytic graphite (HOPG) clearly show the arrangement of metal ions (Mn, Cs) in the Mn(10)Cs(2) linear cluster assembly.

15.
Dalton Trans ; 41(12): 3553-61, 2012 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-22310968

RESUMEN

Reaction of nickel(II) chloride hexahydrate with N-n-butyldiethanolamine H(2)L (3) in the presence of LiH in anhydrous THF leads to the formation of the unique octanuclear chloro-bridged nickel(II) double cubane [({Ni(II)(4)(µ(3)-OH)Cl(3)(HL)(3)}µ(2)-Cl)(2)] (4) in 57% yield. According to single crystal X-ray structure analysis, complex 4·4CH(2)Cl(2) possesses a [({Ni(4)(µ(3)-OH)(µ(3)-O)(3)(OH)(3)(N)(3)(Cl)(3)}µ(2)-Cl)(2)] core and crystallizes in the monoclinic space group P2(1)/c with a = 18.292(2), b = 19.8972(5), c = 23.295(2) Å, ß = 98.408(6)°, V = 8387.3(8) Å(3), and four molecules in the unit cell. The analysis of the SQUID magnetic susceptibility data identified 4 as a weakly coupled dimer (J(1) = 14.5 K, J(2) = -0.6 K) with a ground state of S = 0, resulting from two S = 4 states of each {Ni(4)} subunits. Although complex 4 does not show an ac out-of-phase signal in a zero dc field at temperatures of 1.8 K and higher, low-temperature magnetization measurements revealed that complex 4 is a single-molecule magnet and shows hysteretic magnetization characteristics with typical temperature and sweep-rate dependencies. The eye-catching feature of complex 4 is the presence of two different blocking temperatures (0.9 K around zero field and 1.3 K at higher fields). The origin of this highly unusual behavior can be assigned to the dimer-nature of the interaction between the two S = 4 units. Furthermore STM and current imaging tunnelling spectroscopy (CITS) were performed on aggregates of 4 drop-coated on highly oriented pyrolytic graphite (HOPG) surfaces. CITS measurements show a strong contrast in the area of the nickel centers and a HOMO-LUMO gap of approximately 0.8 V.

16.
Trop Med Health ; 40(4): 133-9, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23532674

RESUMEN

More than 20 million people in Bangladesh are considered at risk of developing visceral leishmaniasis (VL). A community-based active surveillance was conducted in eight randomly selected villages in a highly endemic area of Bangladesh from 2006 to 2008. A total of 6,761 individuals living in 1,550 mud-walled houses were included in the active surveillance. Rapid rK39 dipstick tests were conducted throughout the study period to facilitate the case diagnosis. Individuals with previous or current clinical leishmaniasis were identified on the basis of the case definition of the VL elimination program. Untreated cases of suspected VL were referred to the hospital for treatment. Socioeconomic and environmental information including bed net use was also collected. In 2006, the annual incidence of clinical leishmaniasis in the study area was 141.9 cases per 10,000 population, which was significantly increased by the following year owing to community-based active surveillance for case detection and reporting. However, early case detection and early referral for treatment led to a significant decrease in incidence in 2008. This study suggests that community-based active surveillance using a simple diagnostic tool might play a role in achieving the goal of the VL elimination program.

17.
Appl Opt ; 50(28): 5545-54, 2011 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-22016224

RESUMEN

Spectral variability remains a major challenge for target detection in hyperspectral imagery (HSI). Recently, the spectral fringe-adjusted joint transform correlation (SFJTC) technique has been used effectively for hyperspectral target detection applications. In this paper, we propose to use discrete wavelet transform (DWT) coefficients of the signatures as features for detection in order to make the SFJTC technique more insensitive to spectral variability. We devised a supervised training algorithm that uses the pure target signature and randomly selected samples from input scenery to select an optimal set of DWT coefficients for detection. We have inserted target signatures into urban and vegetative hyperspectral scenery with varying levels of spectral variability to explore the performance of our DWT-based SFJTC technique in different operating conditions. Detection results in the form of receiver-operating-characteristic (ROC) curves and area-under-the-ROC (AUROC) curves show that the proposed scheme yields the largest mean AUROC values compared to SFJTC using the original signatures and traditional hyperspectral detection algorithms.

18.
Helicobacter ; 16(3): 169-78, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21585602

RESUMEN

BACKGROUND: Helicobacter pylori (H. pylori) is a gram negative bacterium that can cause diseases such as peptic ulcers and gastric cancer. IL-17A, a proinflammatory cytokine that can induce the production of CXC chemokines for neutrophil recruitment, has recently been shown to be elevated in both H. pylori-infected patients and mice. Furthermore, studies in mouse models of vaccination have reported levels significantly increased over infected, unimmunized mice and blocking of IL-17A during the challenge phase in immunized mice reduces protective immunity. Because many aspects of immunity had redundant or compensatory mechanisms, we investigated whether mice could be protectively immunized when IL-17A function is absent during the entire immune response using IL-17A and IL-17A receptor knockout (KO) mice immunized against H. pylori. MATERIALS AND METHODS: Gastric biopsies were harvested from naïve, unimmunized/challenged, and immunized/challenged wild type (WT) and KO mice and analyzed for inflammation, neutrophil, and bacterial levels. Groups of IL-17A KO mice were also treated with anti-IFNγ or control antibodies. RESULTS: Surprisingly, all groups of immunized KO mice reduced their bacterial loads comparably to WT mice. The gastric neutrophil counts did not vary significantly between IL-17A KO and WT mice, whereas IL-17RA KO mice had on average a four-fold decrease compared to WT. Additionally, we performed an immunization study with CXCR2 KO mice and observed significant gastric neutrophils and reduction in bacterial load. CONCLUSION: These data suggest that there are compensatory mechanisms for protection against H. pylori and for neutrophil recruitment in the absence of an IL-17A-CXC chemokine pathway.


Asunto(s)
Vacunas Bacterianas/inmunología , Infecciones por Helicobacter/inmunología , Helicobacter pylori/inmunología , Interleucina-17/deficiencia , Animales , Vacunas Bacterianas/administración & dosificación , Femenino , Mucosa Gástrica/inmunología , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/prevención & control , Helicobacter pylori/genética , Humanos , Inmunización , Interleucina-17/genética , Interleucina-17/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Neutrófilos/inmunología , Receptores de Interleucina-17/genética , Receptores de Interleucina-17/inmunología
19.
Appl Opt ; 49(10): B18-25, 2010 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-20357838

RESUMEN

A novel spectral fringe-adjusted joint transform (SFJTC) correlation based technique is proposed for detecting very small targets involving only a few pixels in hyperspectral imagery. In this technique, spectral signatures from the unknown hyperspectral imagery are correlated with the reference signature using the SFJTC technique. This technique can detect both single and/or multiple desired targets in constant time while accommodating the in-plane and out-of-plane distortions. Furthermore, in this paper, a new metric, called the peak-to-clutter mean, is introduced that provides sharp and high correlation peaks corresponding to targets and makes the proposed technique intensity invariant. Test results using real life hyperspectral image datacubes are presented to verify the effectiveness of the proposed technique.

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