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1.
Microb Pathog ; 186: 106495, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38070626

RESUMEN

Quorum sensing (QS) is a molecular cell-cell communication utilized by several bacteria and some fungi. It involves cell density dependent gene expression that includes extra polymeric substance production, sporulation, antibiotic production, motility, competence, symbiosis and conjugation. These expressions were carried out by different signaling molecules like acyl homo-serine lactone (AHL) and auto-inducing peptides (AIPs) which was effluxed by gram negative and gram positive bacteria. Pathogenic bacteria and biofilms often exhibit high resistance to antibiotics, attributed to the presence of antibiotic efflux pumps, reduced membrane permeability, and enzymes that deactivate quorum sensing (QS) inhibitors. To counteract virulence and multi-drug resistance (MDR), novel strategies such as employing quorum sensing (QS) inhibitors and quorum quenchers are employed. It targets signaling molecules with synthesis and prevents the signal from binding to receptors. In this present review, the mechanisms of QS along with inhibitors from different sources are described. These strategies potentially interfere with QS and it can be applied in different fields, mainly in hospitals and marine environments where the pathogenic infections and biofilm formation are highly involved.


Asunto(s)
Bacterias , Percepción de Quorum , Biopelículas , Antibacterianos/farmacología , Antibacterianos/metabolismo , Bacterias Grampositivas
2.
Luminescence ; 39(8): e4862, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39129445

RESUMEN

The present work investigates the structural and luminescence behaviour of Dy3+-Sm3+ co-doped glass ceramics obtained through heat treatment of precursor glasses. The growth of SiO2 polycrystalline particles and evolution of these crystallites in the glass domain are witnessed via XRD and FESEM study. The presence of network vibrational bands, hydroxyl groups and the increased quantity of bridging oxygens (BOs) in glass ceramics are analysed through FTIR spectroscopy study. The absorption study (UV-Visible-NIR) showed the possible electronic transitions of Dy3+ and Sm3+ ions. The red shift in the absorption band edges and the lower bandgap values are obtained as a result of improved heat treatment in glass ceramics. Emission studies show the enhanced luminescence intensity of glass ceramics under 350 and 402 nm excitations. Decay measurement of glass ceramics showed the improved lifetimes of Dy3+ and Sm3+ ions to have appeared in microseconds (×10-6 s). The colour characteristics of glass ceramics analysed using CIE colour chromaticity diagram and correlated colour temperature (CCT) values suggest the neutral to cool white light emissions. Therefore, prepared glass ceramics with SiO2 polycrystalline phase are considered to be suitable materials in cool white LEDs applications.


Asunto(s)
Cerámica , Cristalización , Disprosio , Luminiscencia , Samario , Dióxido de Silicio , Cerámica/química , Dióxido de Silicio/química , Disprosio/química , Samario/química , Luz , Vidrio/química
3.
Afr J Reprod Health ; 28(9): 136-144, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39373156

RESUMEN

complications, infectious diseases, maternal and infant health in disasters, gender-based violence, healthcare access inequities, mental health impacts, and food security issues. Findings reveal an uneven distribution of coverage across continents, with potential language bias in English-dominated sources. Acknowledging limitations, future research directions emphasize a more inclusive approach, incorporating diverse linguistic perspectives and qualitative exploration of community experiences. The study underscores the imperative for global representation in media discourse This research explores the intricate relationship between climate change and reproductive health through an analysis of 1000 global news articles from 2018 onwards. Utilizing Latent Dirichlet Allocation (LDA), key topics in media coverage are identified, encompassing fertility challenges, pregnancy and advocates for comprehensive, evidence-based strategies to address the complex interplay between climate change and reproductive health.


Cette recherche explore la relation complexe entre le changement climatique et la santé reproductive à travers une analyse de 1 000 articles de presse mondiaux à partir de 2018. Grâce à l'allocation de Dirichlet latente (LDA), des sujets clés de la couverture médiatique sont identifiés, englobant les problèmes de fertilité, les complications de la grossesse, les maladies infectieuses, la santé maternelle et infantile en cas de catastrophe, la violence sexiste, les inégalités d'accès aux soins de santé, les impacts sur la santé mentale et les problèmes de sécurité alimentaire. . Les résultats révèlent une répartition inégale de la couverture à travers les continents, avec un biais linguistique potentiel dans les sources à dominante anglaise. Reconnaissant les limites, les futures orientations de recherche mettent l'accent sur une approche plus inclusive, intégrant diverses perspectives linguistiques et une exploration qualitative des expériences communautaires. L'étude souligne l'impératif d'une représentation mondiale dans le discours médiatique et préconise des stratégies globales et fondées sur des preuves pour aborder l'interaction complexe entre le changement climatique et la santé reproductive.


Asunto(s)
Cambio Climático , Periodismo , Salud Reproductiva , Humanos , Femenino , Embarazo
4.
Nanotechnology ; 35(1)2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37793353

RESUMEN

We report on the superconducting properties and intermediate resistive steps (IRS) observed in the current-voltage characteristics (IVC) of tungsten meander (MW) structures fabricated using focused ion beam (FIB) technique. Three number of MWs were studied with individual wire widths of 240 nm, 640 nm and 850 nm with superconducting transition temperatures (TC) of 4.5 K, 4.55 K and 4.60 K respectively. The measured normal state resistance values at 8 K for these wires are of ∼182 kΩ, ∼49 kΩ and ∼32 kΩ, respectively as a function of increasing wire widths; are higher than the quantum of resistance (h/4e2=6.45kΩ,his a Planck constant andeis electronic charge) indicating extreme disorder nature of the fabricated samples. The variation of resistance with respect to temperature (forT

5.
J Fluoresc ; 32(4): 1557-1563, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35553318

RESUMEN

The present work describes the synthesis and characterization of pyrene derivatives, N-(1-Pyrenoylmethyl) pyridinium bromide (PM-PB) and N-(1-Pyrenoylmethyl)-N,N,N-triethylammonium bromide (PM-TAB). The photophysical behavior of these molecules has been studied in various protic and aprotic solvents. Using steady state fluorescence intensity, fluorescence anisotropy and dynamic fluorescence lifetime studies, the sensitivity of these molecules towards the micellization process of bile salts has been monitored. These derivatives have been effectively used in estimating critical micellar concentration (CMC) of bile salt, sodium deoxycholate (NaDC).


Asunto(s)
Ácidos y Sales Biliares , Sales (Química) , Bromuros , Ácido Desoxicólico , Micelas
6.
Microb Pathog ; 121: 155-165, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29778820

RESUMEN

The present study was aimed to evaluate the antimicrobial activities of bioactive compounds synthesized from vermicast isolated actinomycetes species. Specifically, the synthesized bioactive compounds were evaluated for their antimicrobial activity against selected Gram + ve and Gram - ve human pathogenic bacteria including Staphylococcus aureus, Bacillus circulans, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli. Interestingly, a total of five different actinomycetes species were recovered from vermicasts. More interestingly, among these potential actinomycetes species, the bioactive compounds synthesized by isolate AS9 showed a significant antibacterial activity and its mean zone of inhibition was found at 11.3 ±â€¯1.6 mm, 9.5 ±â€¯0.91 mm, and 9.9 ±â€¯1.71mm against S. aureus, B. subtilis, and B. circulans, respectively. Furthermore, according to antibacterial activity and spectrum broadness, three of the actinomycetes strains were selected and characterized by conventional methods. Subsequently, the bioactive compound profiling of these isolated actinomycetes strains performed through GC-MS analysis indicating the presence of the bioactive compounds including 3, octadecene (E), behnic alcohol phenol, 2,4-bis(1,1-dimethyl ethyl) 1-nonadecene, 1-heneicosanol, milbemycin 3-eicosene (E), and 1-docosanol.


Asunto(s)
Actinobacteria/metabolismo , Antibacterianos/farmacología , Actinobacteria/clasificación , Actinobacteria/aislamiento & purificación , Antibacterianos/aislamiento & purificación , Bacillus/efectos de los fármacos , Bacillus subtilis/efectos de los fármacos , ADN Bacteriano/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/metabolismo , Cromatografía de Gases y Espectrometría de Masas , India , Filogenia , Pseudomonas aeruginosa/efectos de los fármacos , ARN Ribosómico 16S/genética , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/efectos de los fármacos
7.
Microb Pathog ; 115: 57-63, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29248514

RESUMEN

Zinc oxide nanoparticles (ZnONPs) exhibit abundant biomedical applications. Anisotropic ZnONPs with a defined shape and size were synthesized using Bacillus megaterium (NCIM 2326) cell free extract as a bio-reductant. The study investigated the multidimensional effect of ZnONPs on Helicobacter pylori strains and assessed its biosafety in normal human mesenchymal stem cells (hMSc). The highly stable ZnONPs were produced using B. megaterium and Zinc nitrate as a precursor. The phase of ZnONPs formation and structural characterization were performed by UV- visible (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Field Emission Scanning electron microscopy (FESEM) analysis. Furthermore, the ZnONPs exhibited higher biocompatibility against human mesenchymal stem cells (hMSC) and proved to be potentially safe in mammalian cells. Corroborating the current investigation, we described the anti-H. Pylori dosage of ZnONPs was safe to hMSC and could efficiently use as nano-antibiotic.


Asunto(s)
Antibacterianos/farmacología , Tecnología Química Verde/métodos , Nanopartículas del Metal/química , Óxido de Zinc/farmacología , Anisotropía , Antibacterianos/química , Apoptosis/efectos de los fármacos , Bacillus megaterium/metabolismo , Membrana Celular/efectos de los fármacos , Helicobacter pylori/efectos de los fármacos , Humanos , Ensayo de Materiales , Células Madre Mesenquimatosas/efectos de los fármacos , Nanopartículas del Metal/ultraestructura , Pruebas de Sensibilidad Microbiana , Tamaño de la Partícula , Especies Reactivas de Oxígeno/metabolismo , Óxido de Zinc/metabolismo
8.
J Med Syst ; 42(11): 208, 2018 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-30244385

RESUMEN

Security is the most critical issue amid transmission of medical images because it contains sensitive information of patients. Medical image security is an essential method for secure the sensitive data when computerized images and their relevant patient data are transmitted across public networks. In this paper, the dual encryption procedure is utilized to encrypt the medical images. Initially Blowfish Encryption is considered and then signcryption algorithm is utilized to confirm the encryption model. After that, the Opposition based Flower Pollination (OFP) is utilized to upgrade the private and public keys. The performance of the proposed strategy is evaluated using performance measures such as Peak Signal to Noise Ratio (PSNR), entropy, Mean Square Error (MSE), and Correlation Coefficient (CC).


Asunto(s)
Algoritmos , Seguridad Computacional , Diagnóstico por Imagen , Entropía , Humanos , Relación Señal-Ruido
9.
J Contemp Dent Pract ; 18(1): 49-51, 2017 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-28050985

RESUMEN

INTRODUCTION: Implant-supported prosthesis has high predictability and success and improves quality of life. This study aims at assessing awareness among the patients regarding implant-supported prosthesis. MATERIALS AND METHODS: A cross-sectional study was conducted among 391 study participants. A structured questionnaire was distributed to assess implant-related awareness among the study participants. The questionnaires were analyzed for the responses. RESULTS: Among the 391 respondents, 37.5% of the respondents reported having moderate knowledge regarding the tooth replacement options. Nearly 50% considered implants as a viable treatment option. The majority of them enlisted the dentist as the major source of information regarding implants, and media had a share of about 7.03% only. High cost was a major barrier in selecting implants as a treatment option. CONCLUSION: This survey showed that awareness among people was low regarding the dental implants. Efforts need to be directed to increase the awareness levels by utilizing media as a tool to achieve the target. CLINICAL SIGNIFICANCE: A patient who is aware of the advantages of the implant-supported dentures will make an informed decision for better functional stability and retention of the denture, especially in the mandibular arch.


Asunto(s)
Concienciación , Prótesis Dental de Soporte Implantado/psicología , Conocimiento , Pacientes/psicología , Adolescente , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Adulto Joven
10.
J Appl Microbiol ; 118(3): 557-64, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25495190

RESUMEN

AIMS: This study was carried out to determine the effect of graded levels of tannin-containing tropical tree leaves, Autocarpus integrifolis, Azardirachta indica and Ficus bengalensis, on the in vitro rumen fermentation pattern, total protozoa and methane suppression in order to establish the optimum dose of these leaves for inclusion in the ruminant diets. METHODS AND RESULTS: The air-dried and ground samples of Au. integrifolis, Az. indica and Ficus bengalensis were subjected to in vitro incubation using 30 ml buffered rumen fluid at 0, 2.5, 5.0, 10.0, 15.0, 20.0, 25.0 and 30.0% (dry matter refers to moisture-free basis) of a total mixed ration (TMR: refers to mixture of roughage and concentrate containing cereals and oil cakes) devoid of tannin. The TMR for the experimental incubation was prepared by mixing 40 parts of ground Elusine coracana straw as roughage source with 60 parts of concentrate mixture. The leaves contained an average 130 g kg(-1) CP with 7·0 MJ of ME kg(-1) DM. The average neutral detergent fibre (NDF) content was <400 g kg(-1) DM. Highest total phenol (TP; g kg(-1) DM) was recorded in Az. indica (108) followed by F. bengalensis (103) and Au. integrifolis (76), and total tannin (TT) content also showed similar trend. However, condensed tannin (CT) was highest in F. bengalensis (260) followed by Au. integrifolis (186) and Az. indica (138). There was significant (P < 0.05) reduction in the NH3 concentration in the presence of all the leaves. Autocarpus integrifolis tannins did not cause inhibition of total volatile fatty acid (TVFA: refers to the concentration of volatile fatty acids, viz. acetic, butyric and propionic) concentration, whereas F. bengalensis and Az. indica tannins at higher level of incubation (>5.0%) reduced TVFA concentration. Protozoa (cells per mL) were similar at all levels of inclusion with Au. integrifolis, but reduced in case of F. bengalensis and Az. indica. As the level of tannin increased in the incubation medium, there was a linear reduction in methane concentration. Highest methane reduction (%) was recorded in incubations supplemented with Az. indica (61.5) followed by F. bengalensis (46.8) and Au. integrifolis (30.3). CONCLUSIONS: It was established from this study that tropical leaves of F. bengalensis, Au. integrifolis and Az. indica suppress methanogenesis. SIGNIFICANCE AND IMPACT OF THE STUDY: Ficus bengalensis, Au. integrifolis and Az. indica leaves are of interest in the enteric methane ameliorative strategies. Total mixed ration containing 10-15% ground F. bengalensis or Au. integrifolis or Az. indica leaves could be fed to ruminants to reduce enteric methanogenesis. However, in vivo trials need to be carried out to validate these in vitro results.


Asunto(s)
Fermentación , Metano/metabolismo , Hojas de la Planta/química , Rumen/metabolismo , Taninos/análisis , Alimentación Animal , Animales , Cilióforos/aislamiento & purificación , Fibras de la Dieta , Técnicas In Vitro , Proantocianidinas/análisis , Árboles
11.
Ecotoxicol Environ Saf ; 120: 295-302, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26094035

RESUMEN

The fate and effect of nanomaterials in the environment has raised concern about their environmental risk to aquatic organisms. Silica nanoparticles (SiO2-NPs) find its uses in various fields and are inevitably released into the environment. However, the ecotoxicological effects of SiO2-NPs on the freshwater fish remain poorly understood. The aim of this study was to evaluate the effect of different concentrations (1, 5 and 25mgL(-1)) of SiO2-NPs on certain hematological, ionoregulatory and enzymological profiles of a freshwater teleost fish Labeo rohita. Hematological parameters such as hemoglobin (Hb), hematocrit (Hct), red blood cells (RBC), white blood cells (WBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) values were altered in SiO2-NPs treated groups. Likewise, plasma electrolytes such as plasma sodium (Na(+)), potassium (K(+)) and chloride (Cl(-)) levels and Na(+)/K(+) ATPase activity in gill of SiO2-NPs treated groups were altered in all concentrations throughout the study period (96h). The alterations of these parameters were found to be dependent on dose and exposure period. The results of the present study indicate that the alterations of these parameters may relate to physiological stress system to SiO2-NPs toxicity and also demonstrate that manufactured metal oxide NPs in aquatic environment may affect the health condition of the aquatic organisms.


Asunto(s)
Cyprinidae/metabolismo , Agua Dulce/química , Branquias/efectos de los fármacos , Nanopartículas/toxicidad , Dióxido de Silicio/toxicidad , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Animales , Índices de Eritrocitos , Eritrocitos , Branquias/enzimología , Hematócrito , Hemoglobinas/metabolismo , Recuento de Leucocitos , Nanopartículas/química , Potasio/sangre , Medición de Riesgo , Dióxido de Silicio/química , Sodio/sangre , Pruebas de Toxicidad Aguda , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/toxicidad
12.
J Food Sci Technol ; 52(4): 2485-8, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25829638

RESUMEN

Study on the phase transition characteristics is an important parameter in extrusion processing. The influence of Moisture Content (MC), particle size and level of cereal-pulse blend on the glass transition (Tg) and melt (Tm) temperatures of a ready to eat cereal-pulse formulation was determined. All samples were moisture conditioned in a 9 to 27 % with 3 % interval. Tg and Tm were measured by phase transition analyser (PTA). A substantial decrease in Tg and Tm was observed as moisture content level increased from 9 to 27 %. However Tg and Tm values could not be clearly defined below 9 % moisture content and above 27 % moisture content. The Tg and Tm values of the cereal-pulse formulation were found to be increased with increasing pulse composition (5 to 30 % with 5 % interval). Increase in particle size (150, 180, 212, 300, 425 and 500 µ) exhibited significant increase effect on Tg while less significant effect on Tm. This may be due to crystalline regions which play a role in cross linking amorphous regions of the polymeric network and thus suppress the mobility of amorphous regions. The observed differences in Tg and Tm induced by the moisture content, concentration of Bengal gram and particle size will be useful in simulation and optimization of barrel temperature set during extrusion processing.

13.
Tech Coloproctol ; 18(5): 433-8, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24030783

RESUMEN

BACKGROUND: In complex fistula-in-ano, preoperative imaging can help identify secondary tracts and abscesses that can be missed, leading to recurrence. We evaluated hydrogen peroxide-enhanced endoanal ultrasound (PEEUS) in the characterization of fistula compared with standard clinical and operative assessment. METHODS: Patients with complex fistula-in-ano treated between February 2008 and May 2009 at our institution were prospectively evaluated by PEEUS with recording of the preoperative clinical examination and intraoperative details of the fistula. Of the 135 patients with fistula-in-ano, 68 met the inclusion criteria for complex fistula-in-ano. Correlation of clinical findings and PEEUS to the gold standard intraoperative findings was assessed in characterizing the fistula. The percent agreement between the clinical and PEEUS findings against the gold standard was derived, and the kappa statistic for agreement was determined. RESULTS: The mean age of the cohort was 42.54 ± 10.86 years. The fistula tracts were curvilinear, high, and transsphincteric in 16 (23.53%), 8 (11.76%), and 42 (61.76%) patients, respectively. Secondary tracts and associated abscess cavities were seen in 28 (33.82%) and 35 (51.47%) patients, respectively. PEEUS correlated better than clinical examination with regard to site (92.65 vs 79.41%; p < 0.001) and course (91.18 vs 77.94%; p < 0.001) of secondary tract and associated abscesses (89.71 vs 80.88%; p = 0.02). There was a trend of better correlation of PEEUS compared to clinical examination in classifying the primary tract as per Park's system (88.24 vs 79.41%; p = 0.06), but it did not reach statistical significance. PEEUS and clinical examination were comparable in correlation of the level of the primary tract (kappa: 0.86 vs 0.78; p = 0.22) and the site of internal opening (kappa: 0.97 vs 0.89; p = 0.22). The operative decision was changed in 13 (19.12%) subjects based on PEEUS findings. CONCLUSIONS: PEEUS is a feasible and efficient tool in the routine preoperative assessment of complex fistula-in-ano.


Asunto(s)
Endosonografía/métodos , Peróxido de Hidrógeno , Cuidados Preoperatorios/métodos , Fístula Rectal/diagnóstico por imagen , Adulto , Femenino , Humanos , India , Masculino , Persona de Mediana Edad , Examen Físico , Estudios Prospectivos , Fístula Rectal/cirugía
14.
J Indian Prosthodont Soc ; 24(2): 196-200, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38650345

RESUMEN

BACKGROUND: In-office three-dimensional (3D) printers and metal sleeveless surgical guides are becoming a major trend recently. However, metal sleeve-free designs are reported to be more prone to distortion which might lead to variation in the inner diameter of the drill hole and cause deviation and inaccuracy in the placement of the implant. Carbon fiber nanoparticles are reported to improve the properties of 3D printing resin material in industrial application. AIM: The purpose of the study is to evaluate and compare the wear resistance of 3D-printed implant guides with metal sleeve, sleeve-free, and reinforced sleeve-free resin to the guide drill. MATERIALS AND METHODS: A total of 66 samples with 22 samples in each group. Three groups including 3D-printed surgical guide with metal sleeve (Group A), without metal sleeve (Group B), an carbon fiber reinforced without metal sleeve (Group C) were included in the study. All samples were evaluated before sequential drilling and after sequential drilling using Vision Measuring Machine. The data were tabulated and statistically evaluated. RESULTS: The data obtained were statistically analyzed with one-way analysis of variance and posthoc test. The data obtained for wear observed in the samples showed that the wear was highest in Group B with a mean of 0.5036 ± 0.1118 and the least was observed in Group A with a mean of 0.0228 ± 0.0154 and Group C was almost similar to Group A with mean of 0.0710 ± 0.0381. The results showed there was a significant difference between Group B with Group A and C, respectively (P < 0.05). The results showed that there was no significant difference regarding the wear observed between Groups A and C (P > 0.05). CONCLUSION: The wear observed in the guide with a metal sleeve and carbon fiber reinforced without a metal sleeve was almost similar. The carbon fiber-reinforced guide showed better tolerance to guide drill equivalent to metal sleeve. Thus, carbon fiber nanoparticles reinforced in 3D printing resin have shown improved strength and can be used as a good replacement for a metal sleeve for an accurate placement of the implant.


Asunto(s)
Impresión Tridimensional , Ensayo de Materiales/métodos , Técnicas In Vitro , Metales/química , Fibra de Carbono/química , Resinas Sintéticas/química , Humanos , Implantes Dentales
15.
J Phys Condens Matter ; 36(50)2024 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-39270713

RESUMEN

TheJeff= ½ state: a result of interplay of strong electronic correlations (U) with spin-orbit coupling (SOC) and crystal field splitting, offers a platform in the research of quantum materials. In this context, 4frare-earth based materials offer a fertile playground. Here, strong experimental and theoretical evidences for aJeff= ½ state is established in a three-dimensional spin system NdVO4. Magnetic measurements show the signatures of a SOC drivenJeff= ½ state along with the presence of antiferromagnetic (AFM) interaction between Nd3+moments, whereas, heat capacity reveals the presence of an AFM ordering around 0.8 K, within this state. An entropy of Rln2 (equivalent toJ= ½) is released around 4 K which implies the presence ofJeff= ½ state at low temperatures. Total energy calculations within the density functional theory (DFT) framework reflect the central role of SOC in driving the Nd3+ions to host such a state with AFM correlations between them, which is in agreement with experimental results. Further, DFT + SOC calculations with and without the inclusion ofU, points that electron-electron correlations give rise to the insulating state making NdVO4a potential candidate forU-driven correlated Mott insulator.

16.
PNAS Nexus ; 3(9): pgae363, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39267815

RESUMEN

The ground state of a one-dimensional spin- 1 2 uniform antiferromagnetic Heisenberg chain (AfHc) is a Tomonaga-Luttinger liquid which is quantum-critical with respect to applied magnetic fields up to a saturation field µ 0 H s beyond which it transforms to a fully polarized state. Wilson ratio has been predicted to be a good indicator for demarcating these phases [Phys. Rev. B 96, 220401 (2017)]. From detailed temperature and magnetic field-dependent magnetization, magnetic susceptibility and specific heat measurements in a metalorganic complex and comparisons with field theory and quantum transfer matrix method calculations, the complex was found to be a very good realization of a spin- 1 2 AfHc. Wilson ratio obtained from experimentally obtained magnetic susceptibility and magnetic contribution of specific heat values was used to map the magnetic phase diagram of the uniform spin- 1 2 AfHc over large regions of phase space demarcating Tomonaga-Luttinger liquid, saturation field quantum critical, and fully polarized states. Luttinger parameter and spinon velocity were found to match very well with the values predicted from conformal field theory.

17.
J Appl Microbiol ; 115(2): 455-65, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23621853

RESUMEN

AIMS: The objective of this study was to evaluate the potential of secondary plant metabolites from 38 sources to serve as antimethanogenic additives in ruminant diets. The effect of leaf tannins from these different plant sources on rumen fermentation, protozoal populations and methanogenesis was also studied. METHODS AND RESULTS: Samples (200 mg dry matter, DM) were incubated without and with polyethylene glycol (PEG)-6000 (400 mg DM) as a tannin binder during 24-h incubation in the in vitro Hohenheim gas system. In the leaf samples, total phenol (g kg(-1) DM) was maximum in Pimenta officinalis (312) followed by Oenothera lamarckiana (185) and Lawsonia inermis (105). Of the 38 samples, condensed tannins exceeded 4.0 g kg(-1) in only Alpinia galanga (7.50), Cinnamomum verum (4.58), Pelargonium graveolens (18.7) and Pimenta officinalis (23.2) and were not detected in seven samples. When the bioactivity of the leaf samples was assessed using the tannin bioassay, the percentage increase in the amount of gas produced during incubation of samples with the tannin-binding agent PEG-6000 over the amount produced during incubation without the tannin binder ranged from nil (zero) to 367%, with the highest being recorded with A. galanga leaves. The ratio of methane reduction per ml of total gas reduction was maximum with Rauvolfia serpentina (131.8) leaves, followed by Indigofera tinctoria (16.8) and Withania somnifera (10.2) leaves. Total and differential protozoal counts increased with added PEG in twenty-two samples, maximum being in Pimenta officinalis. Increased accumulation of total volatile fatty acids during incubation with added PEG-6000 was recorded, and the values ranged from zero to 61%. However, the increase was significant in only 11 of the 38 tannin sources tested indicating noninterference of tannin on in vitro fermentation of carbohydrates by the majority of samples tested. Conversely, in 26 of 38 plant sources, the leaf tannins reduced N-digestibility as evidenced by increased accumulation of NH3 -N with added PEG. CONCLUSIONS: Our study unequivocally demonstrated that plants containing secondary metabolites such as Rauvolfia serpentine, Indigofera tinctoria and Withania somnifera have great potential to suppress methanogenesis with minimal adverse effect of feedstuff fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY: It was established that methanogenesis was not essentially related to the density of protozoa population in vitro. The tannins contained in these plants could be of interest in the development of new additives in ruminant nutrition.


Asunto(s)
Amoníaco/metabolismo , Metano/biosíntesis , Hojas de la Planta/metabolismo , Rumen/metabolismo , Animales , Bovinos , Dieta , Ácidos Grasos Volátiles/metabolismo , Fermentación , Gases/metabolismo , Hojas de la Planta/química , Proantocianidinas/metabolismo , Rumen/efectos de los fármacos , Rumen/parasitología , Metabolismo Secundario , Taninos/química , Taninos/metabolismo
18.
Arch Environ Contam Toxicol ; 64(3): 494-503, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23192588

RESUMEN

Oxytetracycline (OTC), an antibacterial agent, is extensively used in aquaculture practices all over the world. Despite its use, the toxicity of OTC to freshwater fish has been scarcely investigated. In this study, Labeo rohita were exposed to different concentrations (20, 40, 60, 80, 100, and 120 mg L(-1)) of OTC. Based on the survival-to-mortality ratio, an 80 mg L(-1) concentration was selected for sublethal toxicity analysis. Fish were exposed to the above-mentioned concentration for a period of 25 days, during which fish were killed at the end of every 5 days to analyse certain hematological and enzymological parameters. During the exposure period, a mixed trend was observed in hemoglobin (Hb), hematocrit, mean cell volume, mean cellular Hb, and mean cellular Hb concentration, whereas decreased red blood cell count and increased white blood cell was noted. A biphasic trend was observed in the enzymatic levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in the vital organs (gill, liver and muscle) of fish. The alterations of these parameters lead to the conclusion that these parameters may be used as biomarkers in monitoring OTC toxicity in aquaculture and fisheries farms.


Asunto(s)
Antibacterianos/toxicidad , Carpas , Oxitetraciclina/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Recuento de Células Sanguíneas , Carpas/sangre , Carpas/metabolismo , Relación Dosis-Respuesta a Droga , Branquias/efectos de los fármacos , Branquias/enzimología , India , Hígado/efectos de los fármacos , Hígado/enzimología , Músculos/efectos de los fármacos , Músculos/enzimología , Análisis de Supervivencia , Pruebas de Toxicidad Subaguda
19.
J Anim Physiol Anim Nutr (Berl) ; 97(3): 446-56, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22385477

RESUMEN

The potential of tannins from 21 medicinal and aromatic plant leaves as antimethanogenic additives in ruminant feeds was investigated. The effect of tannin from these leaves on rumen fermentation parameters, protozoa population and methanogenesis was studied by incubating the samples [200 mg dry matter (DM)] without and with polyethylene glycol (PEG)-6000 (400 mg DM) as a tannin binder during 24-h incubation in the in vitro Hohenheim gas method. Based on the methane percentage estimated in the total gas produced, methane production in millilitre was calculated [methane volume (ml) = methane % × total gas produced (ml) in 24 h]. In the samples, crude protein and neutral detergent fibre (g/kg DM) ranged from 113 to 172 and from 352 to 444 respectively. The total phenol (TP; g/kg DM) content was highest in Terminalia chebula (274) followed by Hemigraphis colorata (71) and Sapindus laurifolia (51) respectively. In the remaining samples, it was <43 g/kg DM. Activity of tannins, as represented by the increase in gas volume on addition of PEG, ranged from 0 to 133%, with the highest being recorded in T. chebula. The per cent increase in methane on PEG addition was 0 for Ammi majus, Aristolochia indica, Cascabela thevetia, Ipomea nil and Lantana camara, illustrating that tannins present in these samples had no effect on methane concentration. The PEG addition increased the total protozoa count by >50% in A. indica and C. thevetica. One of the important findings of our study was that of the 21 samples screened, Entodinia population increased in 12 with PEG as compared to 7 where Holotricha increased, indicating higher susceptibility of Entodinia to tannin. There was no increase in the protozoa population with PEG when incubating Cardiospermum halicacabum, Clerodendrum inerme, Dioscorea floribunda, Nerium oleander and Selastras paniculatus, which strongly suggested that methane suppression recorded in these samples was not because of a defaunating effect of their tannins per se. The fermentation pattern reflected increased total volatile fatty acid (TVFA) concentration from 0 to 28.3% with PEG addition among the leaves. Our results confirmed further observations that methanogenesis in vitro is not essentially related to density of protozoa population. Secondly, medicinal and aromatic plants such as C. inerme, Gymnema sylvestre and Sapindus laurifolia containing tannins appear to have a potential to suppress in vitro methanogenesis.


Asunto(s)
Eucariontes/efectos de los fármacos , Metano/metabolismo , Extractos Vegetales/química , Plantas Medicinales/química , Rumen , Animales , Eucariontes/clasificación , Modelos Biológicos , Hojas de la Planta
20.
Optik (Stuttg) ; 124(3): 238-242, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23378673

RESUMEN

H(2)SO(4) doped polyaniline (PANI) has synthesized by chemical oxidation method. The prepared Polyaniline were annealed at 150 °C, 200 °C and 250 °C for 30 min in vacuum. Crystal size, percentage of crystallinity, total percentage of crystallinity properties of untreated and heat treated PANI samples were studied by using X-ray diffraction pattern. The molecular structure of untreated and heat treated samples were examined by using Fourier transform infrared spectrophotometer. UV study shows π-π* transition of untreated and heat treated of polyaniline were found at 328 and 636 nm. The peak at 636 nm reveals the extension of conjugated polymer. Thermal properties of untreated and heat treated PANI sample measured by using thermo gravimetric analysis and differential scanning calorimetric spectroscopy.

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