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1.
Am J Otolaryngol ; 45(1): 104097, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37952257

RESUMEN

PURPOSE: Rhinoplasty is amongst the most challenging surgeries to perfect and can take decades. This process begins during residency; however, residents often have limited exposure to rhinoplasty during their training and lack a standardized method for systematically analyzing and formulating a surgical plan. The DESS (Deformity, Etiology, Solution, Sequence) is a novel educational format for residents that serves to increase their pre-operative comfort with the surgical evaluation and intraoperative planning for a rhinoplasty. MATERIALS AND METHODS: A qualitative study performed at a tertiary academic institution with an otolaryngology residency program evaluating three consecutive residency classes comprised of four residents per class. A 9-item questionnaire was distributed to measure change in resident comfort after utilizing the DESS during their facial plastics rotation. Questionnaire responses highlighted resident comfort with facial nasal analysis, identifying deformities, suggesting surgical maneuvers, and synthesizing a comprehensive surgical plan. RESULTS: Ten of the twelve residents surveyed responded. Of those that responded, comfort in facial nasal analysis, identification of common nasal deformities, surgical planning, and development of an overall surgical plan were significantly improved after completion of the facial plastic rotation. These residents largely attributed their success to the systematic educational format, with an average score of 4.8/5.0 (SD 0.42). CONCLUSION: While rhinoplasty is a challenging artform to master, systematic approaches to analysis and operative planning are vital for teaching and guiding residents. Through this novel methodology, residents display significant improvement in their comfort with facial nasal analysis and overall surgical preparation.


Asunto(s)
Internado y Residencia , Enfermedades Nasales , Rinoplastia , Humanos , Rinoplastia/métodos , Nariz/cirugía , Educación de Postgrado en Medicina/métodos , Enfermedades Nasales/cirugía
2.
J Org Chem ; 88(10): 6476-6488, 2023 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-36868184

RESUMEN

Four-membered heterocycles offer exciting potential as small polar motifs in medicinal chemistry but require further methods for incorporation. Photoredox catalysis is a powerful method for the mild generation of alkyl radicals for C-C bond formation. The effect of ring strain on radical reactivity is not well understood, with no studies that address this question systematically. Examples of reactions that involve benzylic radicals are rare, and their reactivity is challenging to harness. This work develops a radical functionalization of benzylic oxetanes and azetidines using visible light photoredox catalysis to prepare 3-aryl-3-alkyl substituted derivatives and assesses the influence of ring strain and heterosubstitution on the reactivity of small-ring radicals. 3-Aryl-3-carboxylic acid oxetanes and azetidines are suitable precursors to tertiary benzylic oxetane/azetidine radicals which undergo conjugate addition into activated alkenes. We compare the reactivity of oxetane radicals to other benzylic systems. Computational studies indicate that Giese additions of unstrained benzylic radicals into acrylates are reversible and result in low yields and radical dimerization. Benzylic radicals as part of a strained ring, however, are less stable and more π-delocalized, decreasing dimer and increasing Giese product formation. Oxetanes show high product yields due to ring strain and Bent's rule rendering the Giese addition irreversible.

3.
Int J Geriatr Psychiatry ; 38(1): e5851, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36494919

RESUMEN

INTRODUCTION: Executive function deficits (EFD) in late life depression (LLD) are associated with poor outcomes. Dysfunction of the cognitive control network (CCN) has been posited in the pathophysiology of LLD with EFD. METHODS: Seventeen older adults with depression and EFD were randomized to iTBS or sham for 6 weeks. Intervention was delivered bilaterally using a recognized connectivity target. RESULTS: A total of 89% (17/19) participants completed all study procedures. No serious adverse events occurred. Pre to post-intervention change in mean Montgomery-Asberg-depression scores was not different between iTBS or sham, p = 0.33. No significant group-by-time interaction for Montgomery-Asberg Depression rating scale scores (F 3, 44  = 0.51; p = 0.67) was found. No significant differences were seen in the effects of time between the two groups on executive measures: Flanker scores (F 1, 14  = 0.02, p = 0.88), Dimensional-change-card-sort scores F 1, 14  = 0.25, p = 0.63, and working memory scores (F 1, 14  = 0.98, p = 0.34). The Group-by-time interaction effect for functional connectivity (FC) within the Fronto-parietal-network was not significant (F 1, 14  = 0.36, p = 0.56). No significant difference in the effect-of-time between the two groups was found on FC within the Cingulo-opercular-network (F 1, 14  = 0, p = 0.98). CONCLUSION: Bilateral iTBS is feasible in LLD. Preliminary results are unsupportive of efficacy on depression, executive function or target engagement of the CCN. A future Randomized clinical trial requires a larger sample size with stratification of cognitive and executive variables and refinement in the target engagement.


Asunto(s)
Función Ejecutiva , Estimulación Magnética Transcraneal , Humanos , Anciano , Estimulación Magnética Transcraneal/métodos
4.
BMC Emerg Med ; 23(1): 41, 2023 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-37024777

RESUMEN

BACKGROUND: Urgent and emergency care (UEC) settings provide an opportunity to prevent ill-health and promote healthy lifestyles with potential to screen and deliver interventions to under-served, at-risk populations. The aim of this study was to synthesise and summarise the evidence on the effectiveness and implementation of interventions for health promotion in UEC settings. METHODS: PubMed and Embase (OVID) databases were used to search for studies published in English between January 2010 and January 2023. Systematic reviews and meta-analyses of studies that examined the effectiveness or implementation of face-to-face health promotion interventions for lifestyle behaviours delivered in UEC settings were eligible. Extracted data were synthesised and qualitatively summarised by lifestyle behaviour. Reviews were quality assessed using AMSTAR 2. RESULTS: Eighteen reviews met the inclusion criteria; all included studies were conducted in emergency departments or trauma units. We identified 15 reviews on alcohol interventions (13 on effectiveness; 2 on implementation) and 3 on smoking interventions (effectiveness). There were no reviews of intervention studies targeting physical activity or diet and nutrition. There was heterogeneity across studies for study design, target populations, intervention design and content, comparator/control groups and outcomes assessed. The effectiveness of alcohol and smoking interventions in UEC settings varied but some reviews provided evidence of a significant decrease in alcohol consumption, alcohol-related outcomes and smoking in intervention groups, particularly in the short-term and in specific population groups. Research has focused on 'brief' interventions as part of screening, brief intervention and referral to treatment (SBIRT) approaches. Interventions are delivered by a wide range of staff with substantial variation in design. Alcohol brief interventions appear to be acceptable to UEC patients but clinicians face barriers in delivering them. CONCLUSIONS: UEC settings have been under-researched and appear to be under-utilised for delivering health promotion activities, except for alcohol prevention. Review level evidence suggests alcohol and smoking interventions are warranted in some population groups. However, further research is needed to determine the optimal intervention design, content and delivery mode for lifestyle behaviours which are suitable for implementation in UEC settings and promote long-term intervention effectiveness. Changes in clinical practice may be needed, including increased training, integration into service delivery and supportive policy, to facilitate the implementation of SBIRT for lifestyle behaviours. Interventions may need to be delivered in the wider UEC system such as urgent care centres, minor injury units and walk-in centres, in addition to emergency departments and trauma units, to support and increase health promotion activities in UEC settings.


Asunto(s)
Dieta , Promoción de la Salud , Humanos , Consumo de Bebidas Alcohólicas , Servicio de Urgencia en Hospital , Factores de Riesgo , Metaanálisis como Asunto , Revisiones Sistemáticas como Asunto
5.
Inorg Chem ; 61(20): 8000-8014, 2022 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-35544683

RESUMEN

N-Triphos derivatives (NP3R, R = alkyl, aryl) and asymmetric variants (NP2RXR', R' = alkyl, aryl, X = OH, NR2, NRR') are an underexplored class of tuneable, tripodal ligands in relation to the coordination chemistry of Re and Tc for biomedical applications. Mixed-ligand approaches are a flexible synthetic route to obtain Tc complexes of differing core structures and physicochemical properties. Reaction of the NP3Ph ligand with the Re(V) oxo precursor [ReOCl3(PPh3)2] generated the bidentate complex [ReOCl3(κ2-NP2PhOHAr)], which possesses an unusual AA'BB'XX' spin system with a characteristic second-order NMR lineshape that is sensitive to the bi- or tridentate nature of the coordinating diphosphine unit. The use of the asymmetric NP2PhOHAr ligand resulted in the formation of both bidentate and tridentate products depending on the presence of base. The tridentate Re(V) complex [ReOCl2(κ3-NP2PhOAr)] has provided the basis of a new reactive "metal-fragment" for further functionalization in [3 + 2] mixed-ligand complexes. The synthesis of [3 + 2] complexes with catechol-based π-donors could also be achieved under one-pot, single-step conditions from Re(V) oxo precursors. Analogous complexes can also be synthesized from suitable 99Tc(V) precursors, and these complexes have been shown to exhibit highly similar structural properties through spectroscopic and chromatographic analysis. However, a tendency for the {MVO}3+ core to undergo hydrolysis to the {MVO2}+ core has been observed both in the case of M = Re and markedly for M = 99Tc complexes. It is likely that controlling this pathway will be critical to the generation of further stable Tc(V) derivatives.


Asunto(s)
Fosfinas , Ligandos , Espectroscopía de Resonancia Magnética , Fosfinas/química
6.
Facial Plast Surg ; 38(1): 70-73, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34921357

RESUMEN

The alar-columellar relationship is an important concept for the rhinoplasty surgeon to master. The alar rim in particular is a critical component of the nasal tip, contributing to both overall symmetry and proportion of the nasal base. The retracted ala creates a displeasing aesthetic to the tip complex, distorts the nostril openings, and may have functional implications of the external nasal valve. While alar retraction can occur naturally or as the result of trauma, the majority of cases are post-surgical in nature. Many techniques have been described for correction of alar retraction, most of which require open rhinoplasty and many fail to add the soft tissue within the vestibule necessary to properly lower the alar margin. Herein, we present our experience with the auricular chondrocutaneous composite graft-a simple, reliable, and effective technique to correct moderate to severe alar retraction via either open or endonasal rhinoplasty.


Asunto(s)
Deformidades Adquiridas Nasales , Rinoplastia , Estética Dental , Humanos , Cavidad Nasal , Tabique Nasal , Nariz/cirugía , Deformidades Adquiridas Nasales/cirugía
7.
Breast Cancer Res Treat ; 189(1): 63-80, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34216317

RESUMEN

BACKGROUND: Cancer-associated fibroblasts (CAFs) are recruited to the tumor microenvironment (TME) and are critical drivers of breast cancer (BC) malignancy. Circulating tumor cells (CTCs) travel through hematogenous routes to establish metastases. CTCs circulate both individually and, more rarely, in clusters with other cell types. Clusters of CTCs have higher metastatic potential than single CTCs. Previously, we identified circulating CAFs (cCAFs) in patients with BC and found that while healthy donors had no CTCs or cCAFs, both were present in most Stage IV patients. cCAFs circulate individually, as cCAF-cCAF homotypic clusters, and in heterotypic clusters with CTCs. METHODS: In this study, we evaluate CTCs, cCAFs, and heterotypic cCAF-CTC clusters in patients with stage I-IV BC. We evaluate the association of heterotypic clusters with BC disease progression and metastasis in a spontaneous mouse model. Using previously established primary BC and CAF cell lines, we examine the metastatic propensity of heterotypic cCAF-CTC clusters in orthotopic and tail vein xenograft mouse models of BC. Using an in vitro clustering assay, we determine factors that may be involved in clustering between CAF and BC cells. RESULTS: We report that the dissemination of CTCs, cCAFs, and clusters is an early event in BC progression, and we find these clusters in all clinical stages of BC. Furthermore, cCAFs-CTC heterotypic clusters have a higher metastatic potential than homotypic CTC clusters in vivo. We also demonstrate that the adhesion and stemness marker CD44, found on a subset of CTCs and CAF cells, is  involved in heterotypic clustering of these cells. CONCLUSION: We identify a novel subset of circulating tumor cell clusters that are enriched with stromal CAF cells in BC patient blood and preclinical mouse models of BC metastasis. Our data suggest that clustering of CTCs with cCAFs augments their metastatic potential and that CD44 might be an important mediator of heterotypic clustering of cCAFs and BC cells.


Asunto(s)
Neoplasias de la Mama , Fibroblastos Asociados al Cáncer , Células Neoplásicas Circulantes , Animales , Biomarcadores de Tumor , Fibroblastos Asociados al Cáncer/patología , Recuento de Células , Análisis por Conglomerados , Femenino , Humanos , Ratones , Metástasis de la Neoplasia , Células Neoplásicas Circulantes/patología , Microambiente Tumoral
8.
Breast Cancer Res Treat ; 179(3): 577-584, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31720992

RESUMEN

PURPOSE: Paget's disease (PD) of the breast is an uncommon disease of the nipple usually accompanied by an underlying carcinoma, often HER2 + , and accounting for 0.5-5% of all breast cancer. To date, histogenesis of PD of the breast remains controversial, as two theories-transformation and epidermotropic-have been proposed to explain this disease. Currently, animal models recapitulating PD of the nipple have not been described. METHODS: HER2-enriched DT13 breast cancer cells were injected into the mammary fat pad of NOD scid gamma null (NSG) female mice. Immunohistochemical staining and pathological studies were performed on tumor samples, and diagnosis of PD of the nipple was confirmed by expression of proteins characteristic of Paget cells (epidermal growth factor 2 (HER2), androgen receptor (AR), cytokeratin 7 (CK7), cytokeratin 8/18 (CK8/18), and mucin 1 (MUC1)). In addition, DT13 cells grown in 2D culture and in soft agar assays were sensitive to in vitro treatment with pharmacological inhibitors targeting Her2, adenylyl cyclase, mTOR, and PI3K signaling pathways. RESULTS: Mice developed tumors and nipple lesions that were detected exclusively on the tumor-bearing mammary fat pad. Tumor cells were positive for proteins characteristic of Paget cells. In vitro, DT13 cells were sensitive to inhibition of Her2, adenylyl cyclase, mTOR, and PI3K signaling pathways. CONCLUSIONS: Our results suggest that injection of HER2 + DT13 cells into the mammary fat pad of NSG mice recapitulates critical aspects of the pathophysiology of PD of the nipple, supporting the epidermotropic theory as the more likely to explain the histogenesis of this disease.


Asunto(s)
Neoplasias de la Mama/patología , Glándulas Mamarias Animales/patología , Pezones/patología , Enfermedad de Paget Mamaria/patología , Receptor ErbB-2/metabolismo , Anciano , Animales , Carcinoma Ductal de Mama/patología , Línea Celular Tumoral , Femenino , Humanos , Queratina-18/metabolismo , Queratina-7/metabolismo , Queratina-8/metabolismo , Ratones , Ratones Endogámicos NOD , Ratones SCID , Mucina-1/metabolismo , Trasplante de Neoplasias , Fosfatidilinositol 3-Quinasas/metabolismo , Receptores Androgénicos/metabolismo , Trasplante Heterólogo
9.
Chem Soc Rev ; 48(9): 2566-2595, 2019 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-30843542

RESUMEN

Searching for porous materials that can be employed as solid stationary phases for chromatographic separations, porous membrane matrixes and solid supports for catalysis has become an active research area. Strategies for embedding emerging porous materials in columnar systems and their subsequent applications (separation and catalysis) have been developed, which benefit from the remarkable progress in the discovery and development of porous materials based on metal-organic coordination or dynamic covalent bonding such as metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), porous organic cages, and porous organic polymers. In this review, porous materials that have been confined within capillary columns as packed, monolithic and open tubular columns are discussed. Progress in chromatographic separation and continuous flow catalytic synthesis is reviewed according to three major strategies. Applications of porous materials in membrane-separation fibre membrane systems and microfluidic devices with various functions are also highlighted.

10.
Angew Chem Int Ed Engl ; 59(37): 15798-15802, 2020 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-32893978

RESUMEN

Differential scanning calorimetry (DSC) is increasingly used as evidence to support a favourable safety profile of novel chemistry, or to highlight the need for caution. DSC enables preliminary assessment of the thermal hazards of a potentially energetic compound. However, unlike other standard characterisation methods, which have well defined formats for reporting data, the current reporting of DSC results for thermal hazard assessment has shown concerning trends. Around half of all results in 2019 did not include experimental details required to replicate the procedure. Furthermore, analysis for thermal hazard assessment is often only conducted in unsealed crucibles, which could lead to misleading results and dangerously incorrect conclusions. We highlight the specific issues with DSC analysis of hazardous compounds currently in the organic chemistry literature and provide simple "best practice" guidelines which will give chemists confidence in reported DSC results and the conclusions drawn from them.

11.
Bioscience ; 69(11): 928-943, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31719713

RESUMEN

Human-induced changes to environments are causing species declines. Beyond preserving habitat (in situ), insurance (ex situ) populations are essential to prevent species extinctions. The Conservation Centers for Species Survival (C2S2) is leveraging space of breeding centers and private ranches to produce "source populations"-genetically diverse reservoirs that also support research and reintroductions. The initial focus is on four African antelopes. C2S2 has developed a program, the Source Population Alliance, that emphasizes animals living in spacious, naturalistic conditions in greater numbers than can be accommodated by urban zoos. Simulation modeling demonstrates how herds can rapidly increase population abundance and retain genetic diversity. Advances in genomics and resulting DNA data allow monitoring of genetic diversity and parentage as well as refined decision-making. This approach, neither pure in situ nor ex situ, but rather "sorta situ", is an innovative way of linking public and private sector resources to ensure that endangered species survive.

12.
J Org Chem ; 84(9): 5893-5898, 2019 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-30951630

RESUMEN

2-Azido-4,6-dimethoxy-1,3,5-triazine (ADT) was reported recently as a new "intrinsically safe" diazo-transfer reagent. This assessment was based on differential scanning calorimetry data indicating that ADT exhibits endothermic decomposition. We present DSC data on ADT that show exothermic decomposition with an initiation temperature ( Tinit) of 159 °C and an enthalpy of decomposition (Δ HD) of -1135 J g-1 (-207 kJ mol-1). We conclude that ADT is potentially explosive and must be treated with caution, being of comparable exothermic magnitude to tosyl azide (TsN3). A maximum recommended process temperature for ADT is 55 °C.

13.
Appl Opt ; 58(22): 6027-6037, 2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31503923

RESUMEN

When attempting to integrate single-molecule fluorescence microscopy with microfabricated devices such as microfluidic channels, fabrication constraints may prevent using traditional coverslips. Instead, the fabricated devices may require imaging through material with a different thickness or index of refraction. Altering either can easily reduce the quality of the image formation (measured by the Strehl ratio) by a factor of 2 or more, reducing the signal-to-noise ratio accordingly. In such cases, successful detection of single-molecule fluorescence may prove difficult or impossible. Here we provide software to calculate the effect of non-design materials upon the Strehl ratio or ensquared energy and explore the impact of common materials used in microfabrication.

14.
J Proteome Res ; 17(1): 479-485, 2018 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-29172549

RESUMEN

As wearable fitness devices have gained commercial acceptance, interest in real-time monitoring of an individual's physiological status using noninvasive techniques has grown. Microneedles have been proposed as a minimally invasive technique for sampling the dermal interstitial fluid (ISF) for clinical monitoring and diagnosis, but little is known about its composition. In this study, a novel microneedle array was used to collect dermal ISF from three healthy human donors and compared with matching serum and plasma samples. Using a shotgun quantitative proteomic approach, 407 proteins were quantified with at least one unique peptide, and of those, 135 proteins were differently expressed at least 2-fold. Collectively, these proteins tended to originate from the cytoplasm, membrane bound vesicles, and extracellular vesicular exosomes. Proteomic analysis confirmed previously published work that indicates that ISF is highly similar to both plasma and serum. In this study, less than one percent of proteins were uniquely identified in ISF. Taken together, ISF could serve as a minimally invasive alternative for blood-derived fluids with potential for real-time monitoring applications.


Asunto(s)
Líquido Extracelular/química , Proteómica/métodos , Piel/química , Manejo de Especímenes/métodos , Voluntarios Sanos , Humanos , Agujas , Plasma/química , Suero/química
15.
Nucleic Acids Res ; 44(D1): D515-22, 2016 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-26476456

RESUMEN

Genome-scale metabolic models are mathematically-structured knowledge bases that can be used to predict metabolic pathway usage and growth phenotypes. Furthermore, they can generate and test hypotheses when integrated with experimental data. To maximize the value of these models, centralized repositories of high-quality models must be established, models must adhere to established standards and model components must be linked to relevant databases. Tools for model visualization further enhance their utility. To meet these needs, we present BiGG Models (http://bigg.ucsd.edu), a completely redesigned Biochemical, Genetic and Genomic knowledge base. BiGG Models contains more than 75 high-quality, manually-curated genome-scale metabolic models. On the website, users can browse, search and visualize models. BiGG Models connects genome-scale models to genome annotations and external databases. Reaction and metabolite identifiers have been standardized across models to conform to community standards and enable rapid comparison across models. Furthermore, BiGG Models provides a comprehensive application programming interface for accessing BiGG Models with modeling and analysis tools. As a resource for highly curated, standardized and accessible models of metabolism, BiGG Models will facilitate diverse systems biology studies and support knowledge-based analysis of diverse experimental data.


Asunto(s)
Bases de Datos de Compuestos Químicos , Genoma , Redes y Vías Metabólicas/genética , Modelos Genéticos , Genómica/normas , Bases del Conocimiento , Metabolómica
16.
Mol Pharm ; 14(6): 2010-2023, 2017 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-28445052

RESUMEN

Naturally occurring polymers are promising biocompatible materials that have many applications for emerging therapies, drug delivery systems, and diagnostic agents. The handling and processing of such materials still constitutes a major challenge, which can limit the full exploitation of their properties. This study explores an ambient environment processing technique: coaxial electrospray (CO-ES) to encapsulate genistein (an isoflavonoid and model drug), superparamagnetic iron oxide nanoparticles (SPIONs, 10-15 nm), and a fluorophore (BODIPY) into a layered (triglyceride tristearin shell) particulate system, with a view to constructing a theranostic agent. Mode mapping of CO-ES led to an optimized atomization engineering window for stable jetting, leading to encapsulation of SPIONs within particles of diameter 0.65-1.2 µm and drug encapsulation efficiencies of around 92%. Electron microscopy was used to image the encapsulated SPIONs and confirm core-shell triglyceride encapsulation in addition to further physicochemical characterization (AFM, FTIR, DSC, and TGA). Cell viability assays (MTT, HeLa cells) were used to determine optimal SPION loaded particles (∼1 mg/mL), while in vitro release profile experiments (PBS, pH = 7.4) demonstrate a triphasic release profile. Further cell studies confirmed cell uptake and internalization at selected time points (t = 1, 2, and 4 h). The results suggest potential for using the CO-ES technique as an efficient way to encapsulate SPIONs together with sensitive drugs for the development of multimodal particles that have potential application for combined imaging and therapy.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Nanopartículas de Magnetita/química , Supervivencia Celular , Compuestos Férricos/química , Genisteína/química , Células HeLa , Humanos , Microscopía de Fuerza Atómica , Polímeros/química , Nanomedicina Teranóstica , Triglicéridos/química
17.
J Chem Phys ; 147(21): 214306, 2017 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-29221376

RESUMEN

Increasing interest in the thermodynamics of small and/or isolated systems, in combination with recent observations of negative temperatures of atoms in ultracold optical lattices, has stimulated the need for estimating the conventional, canonical temperature Tcconv of systems in equilibrium with heat baths using eigenstate-specific temperatures (ESTs). Four distinct ESTs-continuous canonical, discrete canonical, continuous microcanonical, and discrete microcanonical-are accordingly derived for two-level paramagnetic spin lattices (PSLs) in external magnetic fields. At large N, the four ESTs are intensive, equal to Tcconv, and obey all four laws of thermodynamics. In contrast, for N < 1000, the ESTs of most PSL eigenstates are non-intensive, differ from Tcconv, and violate each of the thermodynamic laws. Hence, in spite of their similarities to Tcconv at large N, the ESTs are not true thermodynamic temperatures. Even so, each of the ESTs manifests a unique functional dependence on energy which clearly specifies the magnitude and direction of their deviation from Tcconv; the ESTs are thus good temperature estimators for small PSLs. The thermodynamic uncertainty relation is obeyed only by the ESTs of small canonical PSLs; it is violated by large canonical PSLs and by microcanonical PSLs of any size. The ESTs of population-inverted eigenstates are negative (positive) when calculated using Boltzmann (Gibbs) entropies; the thermodynamic implications of these entropically induced differences in sign are discussed in light of adiabatic invariance of the entropies. Potential applications of the four ESTs to nanothermometers and to systems with long-range interactions are discussed.

18.
Ecol Appl ; 26(1): 295-308, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27039526

RESUMEN

Emerging infectious diseases of wildlife are of increasing concern to managers and conservation policy makers, but are often difficult to study and predict due to the complexity of host-disease systems and a paucity of empirical data. We demonstrate the use of an Approximate Bayesian Computation statistical framework to reconstruct the disease dynamics of bovine tuberculosis in Kruger National Park's lion population, despite limited empirical data on the disease's effects in lions. The modeling results suggest that, while a large proportion of the lion population will become infected with bovine tuberculosis, lions are a spillover host and long disease latency is common. In the absence of future aggravating factors, bovine tuberculosis is projected to cause a lion population decline of ~3% over the next 50 years, with the population stabilizing at this new equilibrium. The Approximate Bayesian Computation framework is a new tool for wildlife managers. It allows emerging infectious diseases to be modeled in complex systems by incorporating disparate knowledge about host demographics, behavior, and heterogeneous disease transmission, while allowing inference of unknown system parameters.


Asunto(s)
Búfalos , Simulación por Computador , Leones , Modelos Biológicos , Tuberculosis Bovina/epidemiología , Algoritmos , Animales , Animales Salvajes , Teorema de Bayes , Bovinos , Sudáfrica/epidemiología , Especificidad de la Especie , Tuberculosis Bovina/transmisión
19.
Chemistry ; 21(25): 9034-8, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-25965348

RESUMEN

Herein a new (11) C radiolabelling strategy for the fast and efficient synthesis of thioureas and related derivatives using the novel synthon, (11) CS2 , is reported. This approach has enabled the facile labelling of a potent progesterone receptor (PR) agonist, [(11) C]Tanaproget, by the intramolecular reaction of the acyclic aminohydroxyl precursor with (11) CS2 , which has potential applications as a positron emission tomography radioligand for cancer imaging.


Asunto(s)
Benzoxazinas/química , Radioisótopos de Carbono/química , Lóbulo Parietal/química , Radiofármacos/química , Receptores de Progesterona/química , Tionas/química , Tiourea/síntesis química , Neoplasias de la Mama , Humanos , Tomografía de Emisión de Positrones , Receptores de Progesterona/antagonistas & inhibidores , Tiourea/química
20.
Phys Chem Chem Phys ; 17(29): 18913-23, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-26059193

RESUMEN

Many transition metal complexes exhibit infrared or visible optical absorption arising from d-d transitions that are the key to functionality in technological applications and biological processes. The observed spectral characteristics of the absorption spectra depend on several underlying physical parameters whose relative contributions are still not fully understood. Although conventional arguments based on ligand-field theory can be invoked to rationalize the peak absorption energy, they cannot describe the detailed features of the observed spectral profile such as the spectral width and shape, or unexpected correlations between the oscillator strength and absorption peak position. Here, we combine experimental observations with first-principles simulations to investigate origins of the absorption spectral profile in model systems of aqueous Cu(2+) ions with Cl(-), Br(-), NO2(-) and CH3CO2(-) ligands. The ligand identity and concentration, fine structure in the electronic d-orbitals of Cu(2+), complex geometry, and solvation environment are all found to play key roles in determining the spectral profile. Moreover, similar physiochemical origins of these factors lead to interesting and unexpected correlations in spectral features. The results provide important insights into the underlying mechanisms of the observed spectral features and offer a framework for advancing the ability of theoretical models to predict and interpret the behavior of such systems.

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