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1.
Am Sociol ; : 1-13, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36855521

RESUMO

In this review essay, we probe three main elements of Laura Ford's Intellectual Property of Nations: her discussion of the structure of moral obligation and its materialization via writing and the institutions of the law; reflections on how the book intersects with questions of textual epistemology (especially the question of inferring intent from texts); and, finally, a self-consciously "presentist" discussion of how the book's findings intersect with our modern world of global legal regimes.

2.
Int J Mol Sci ; 24(4)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36835401

RESUMO

Melphalan (Mel) is an antineoplastic widely used in cancer and other diseases. Its low solubility, rapid hydrolysis, and non-specificity limit its therapeutic performance. To overcome these disadvantages, Mel was included in ß-cyclodextrin (ßCD), which is a macromolecule that increases its aqueous solubility and stability, among other properties. Additionally, the ßCD-Mel complex has been used as a substrate to deposit silver nanoparticles (AgNPs) through magnetron sputtering, forming the ßCD-Mel-AgNPs crystalline system. Different techniques showed that the complex (stoichiometric ratio 1:1) has a loading capacity of 27%, an association constant of 625 M-1, and a degree of solubilization of 0.034. Added to this, Mel is partially included, exposing the NH2 and COOH groups that stabilize AgNPs in the solid state, with an average size of 15 ± 3 nm. Its dissolution results in a colloidal solution of AgNPs covered by multiple layers of the ßCD-Mel complex, with a hydrodynamic diameter of 116 nm, a PDI of 0.4, and a surface charge of 19 mV. The in vitro permeability assays show that the effective permeability of Mel increased using ßCD and AgNPs. This novel nanosystem based on ßCD and AgNPs is a promising candidate as a Mel nanocarrier for cancer therapy.


Assuntos
Nanopartículas Metálicas , beta-Ciclodextrinas , Melfalan , Prata , beta-Ciclodextrinas/química , Solubilidade
3.
Front Chem ; 10: 809863, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35559213

RESUMO

Optically excited triplet states of organic molecules serve as an energy pool for the subsequent processes, either photon energy downhill, such as room temperature phosphorescence, or photon energy uphill process-the triplet-triplet annihilation upconversion (TTA-UC). Manifestation of a high intersystem crossing coefficient is an unavoidable requirement for triplet state formation, following the absorption of a single photon. This requirement is even more inevitable if the excitation light is non-coherent, with moderate intensity and extremely low spectral power density, when compared with the light parameters of 1 Sun (1.5 AM). Coordination of a heavy atom increases substantially the probability of intersystem crossing. Nevertheless, having in mind the global shortage in precious and rare-earth metals, identification of metal-free organic moieties able to form triplet states becomes a prerequisite for environmental friendly optoelectronic technologies. This motivates us to synthesize a metal-free thienothiophene containing porphyrin, based on a condensation reaction between thienothiophene-2-carbaldehyde and pyrrole in an acidic medium by modified synthetic protocol. The upconversion couple tetrathienothiophene porphyrin/rubrene when excited at λ = 658 nm demonstrates bright, delayed fluorescence with a maximum emission at λ = 555 nm. This verifies our hypothesis that the ISC coefficient in thienothiophene porphyrin is efficient in order to create even at room temperature and low-intensity optical excitation densely populated organic triplet ensemble and is suitable for photon energy uphill processes, which makes this type of metal-free sensitizers even more important for optoelectronic applications.

4.
Proc Natl Acad Sci U S A ; 118(40)2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34580228

RESUMO

Heavy enzyme isotope effects occur in proteins substituted with 2H-, 13C-, and 15N-enriched amino acids. Mass alterations perturb femtosecond protein motions and have been used to study the linkage between fast motions and transition-state barrier crossing. Heavy enzymes typically show slower rates for their chemical steps. Heavy bacterial methylthioadenosine nucleosidases (MTANs from Helicobactor pylori and Escherichia coli) gave normal isotope effects in steady-state kinetics, with slower rates for the heavy enzymes. However, both enzymes revealed rare inverse isotope effects on their chemical steps, with faster chemical steps in the heavy enzymes. Computational transition-path sampling studies of H. pylori and E. coli MTANs indicated closer enzyme-reactant interactions in the heavy MTANs at times near the transition state, resulting in an improved reaction coordinate geometry. Specific catalytic interactions more favorable for heavy MTANs include improved contacts to the catalytic water nucleophile and to the adenine leaving group. Heavy bacterial MTANs depart from other heavy enzymes as slowed vibrational modes from the heavy isotope substitution caused improved barrier-crossing efficiency. Improved sampling frequency and reactant coordinate distances are highlighted as key factors in MTAN transition-state stabilization.


Assuntos
Isótopos/metabolismo , Purina-Núcleosídeo Fosforilase/metabolismo , Catálise , Domínio Catalítico/fisiologia , Escherichia coli/metabolismo , Helicobacter pylori/metabolismo , Cinética , Movimento (Física)
5.
Serv. soc. soc ; (141): 204-223, maio-ago. 2021.
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1252228

RESUMO

Resumo: Este artigo tem como objetivo compreender como, de maneira aparentemente paradoxal no Brasil, com uma sociedade erigida em estreita relação com o Continente Africano, se construiu um Estado que desde suas primeiras décadas de existência mostrou-se hostil aos africanos e a seus descendentes, promovendo, ao contrário, a continuidade de uma civilização europeia nos trópicos.


Abstract: This article aims to understand how, in an apparently paradoxical way in Brazil, with a society erected in a close relationship with the African Continent, a State that since its first decades of existence has showed itself hostile to africans and their descendants was built, promoting, on the contrary, the continuation of an european civilization in the tropics.

6.
Int J Drug Policy ; 89: 103091, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33423917

RESUMO

Many discussions of mafia and criminal entrepreneurs typically focus on violence and illegality, and less on their possible roles in rural transformation, even when they are located in borderland economies linking the subsistence cultivators of illicit crops to regional and global markets. This paper assesses the life stories of drug lords, the Castaño brothers of Colombia and Roberto Suárez Gomez of Bolivia, to draw inferences into how such rural elites in the illicit drugs trade are not only specialists in crime but are also actors who regulate and manipulate, often coercively, access to land and resources, mobilise labour and shape its divisions, and promote certain forms of capital accumulation. This paper contends that a better understanding of the roles of these rural elites as pioneers for capital, intermediaries in commodity chains, and arbitrageurs between state and borderlands may provide ways of unpacking key challenges to peacebuilding and economic transformation in borderlands where illicit economies thrive.


Assuntos
Coca , Criminosos , Drogas Ilícitas , Bolívia , Colômbia , Humanos
7.
Br J Sociol ; 72(2): 379-396, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32483840

RESUMO

Drawing from theory on the "co-production" of science and society, this paper provides an account of trajectories in US climatology, roughly from the 1850s to 1920, the period during which climatology emerged as an organized branch of meteorology and government administration. The historical narrative traces the development of climatology both as a professional/institutional project and as a component of a larger governmental logic. Historical analysis of climatologists' scientific texts, maps, and social organization within government provides a sociological explanation for the emergent "stabilization" of climate as a geographic-statistical category. Climatic stability, defined by the view that climate is unchanging, was advanced over this period in a way that linked the interests and practices of climatologists to actors invested in facilitating and administrating commercial agriculture and trade. I position the logic of climatology and the discourse of climatic stability historically, with reference to prior concern with climate change and, in recent decades, efforts to govern global warming through geoengineering climatic stability.


Assuntos
Capitalismo , Meteorologia , Agricultura , Mudança Climática , Humanos , Sociologia , Estados Unidos
8.
Chemistry ; 27(8): 2683-2691, 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32681763

RESUMO

Photogenerated multi-spin systems hold great promise for a range of technological applications in various fields, including molecular spintronics and artificial photosynthesis. However, the further development of these applications, via targeted design of materials with specific magnetic properties, currently still suffers from a lack of understanding of the factors influencing the underlying excited state dynamics and mechanisms on a molecular level. In particular, systematic studies, making use of different techniques to obtain complementary information, are largely missing. This work investigates the photophysics and magnetic properties of a series of three covalently-linked porphyrin-trityl compounds, bridged by a phenyl spacer. By combining the results from femtosecond transient absorption and electron paramagnetic resonance spectroscopies, we determine the efficiencies of the competing excited state reaction pathways and characterise the magnetic properties of the individual spin states, formed by the interaction between the chromophore triplet and the stable radical. The differences observed for the three investigated compounds are rationalised in the context of available theoretical models and the implications of the results of this study for the design of a molecular system with an improved intersystem crossing efficiency are discussed.

9.
Middle East Stud ; 55(5): 837-853, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31391656

RESUMO

Giorgio Agamben argues that in contemporary governance the use of 'emergency' is no longer provisional, but 'constitutes a permanent technology of government' and has produced the extrajudicial notion of crisis. The engendering of 'zones of indistinction' between the law and its practice is what Agamben defines as a 'state of exception'. This article adopts the notion enunciated by Agamben and revisits it in the Islamic Republic of Iran. There, the category of crisis has been given, firstly, a juridical status through the institution of maslahat, 'expediency', interpreted in a secular encounter between Shica theological exegesis and modern statecraft. Secondly, crisis has not led to the production of a 'state of exception' as Agamben argues. Instead, since the late 1980s, a sui generis institution, the Expediency Council, has presided and decided over matters of crisis. Instead of leaving blind spots in the production of legislative power, the Expediency Council takes charge of those spheres of ambiguity where the 'normal' - and normative - means of the law would have otherwise failed to deliver. This is a first study of this peculiar institution, which invites further engagement with political phenomena through the deconstruction and theorization of crisis politics.

10.
Proc Natl Acad Sci U S A ; 116(17): 8233-8238, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30936312

RESUMO

Considerable debate surrounds the economic, political, and ideological systems that constitute primary state formation. Theoretical and empirical research emphasize the role of religion as a significant institution for promoting the consolidation and reproduction of archaic states. The Tiwanaku state developed in the Lake Titicaca Basin between the 5th and 12th centuries CE and extended its influence over much of the south-central Andes of South America. We report on recent discoveries from the first systematic underwater archaeological excavations in the Khoa Reef near the Island of the Sun, Bolivia. The depositional context and compositional properties of offerings consisting of ceramic feline incense burners, killed juvenile llamas, and sumptuary metal, shell, and lapidary ornaments allow us to reconstruct the structure and significance of cyclically repeated state rituals. Using new theoretical tools, we explain the role of these rituals in promoting the consolidation of the Tiwanaku polity.


Assuntos
Comportamento Ritualístico , Indígenas Sul-Americanos/história , Religião/história , Arqueologia , Bolívia/etnologia , História Medieval , Humanos , Ilhas , Lagos , Política
11.
R Soc Open Sci ; 5(5): 171137, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29892345

RESUMO

The relationship between organizational complexity and demographic scale is an enduring research problem at the intersection of the natural and social sciences and has far reaching implications for the study of social evolution, particularly the emergence and collapse of complex social organizations such as chiefdoms, states and empires. Anthropological models of social evolution universally assume that population growth plays a critical role in the development of organizational complexity; however, the relationship between organizational complexity and demographic scale has not been formalized and cross-culturally validated. There is a rich yet unsystematized body of diachronic organizational and demographic data describing the evolution of organizational complexity in 10 archaeologically known cases of primary state formation. Using this dataset, this essay proposes and tests a complex network model that describes state societies as discrete, self-similar, hierarchical social networks. The model accurately describes how organizational complexity and population scale in all cases. The complex network architecture of state societies suggests that further advances in our understanding of modern social organization may be found by a deeper investigation of the role of human nature in the evolution of human societies.

12.
J Archaeol Method Theory ; 24(2): 611-639, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29266113

RESUMO

We apply a phenomenological perspective on landscape and geographic information system (GIS) applications in order to theorize how human perception and agency were likely implicated in processes of the formation of the late pre-Hispanic Tarascan State of West Central Mexico. The relatedness of landscape features in space or place-based perception has been well theorized; here, we further consider the relationality of places through time. In the changing landscape of the Lake Pátzcuaro Basin, the demographic and political core of the Tarascan State, temporality must have been vitally important to inhabitants of the basin. Utilizing GIS, we construct not only map-based analyses of the changing environment but also create viewsheds of past landscapes in order to see what past inhabitants of the basin would have seen in order to demonstrate that temporality would have been easily mapped in the landscape and its features. Finally, we discuss the role of temporality and cultural memory in an embodied landscape to model the various lake levels that past peoples could have anticipated through time based on their perceptions and memories.

13.
Soc Sci Med ; 170: 87-96, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27768942

RESUMO

Decolonization has brought political independence to half the Caribbean states in the last half of the 20th century, while the other states remain affiliated. Previous studies suggested a beneficial impact of affiliated status on population health, which may be mediated by more favorable economic development. We assessed how disparities in life expectancy between currently sovereign and affiliated states developed over time, whether decolonization coincided with changes in life expectancy, and whether decolonization coincided with similar changes in GDP per capita. Time-series data on life expectancy and related variables, GDP per capita and political status were collected from harmonized databases. We quantified variations in life expectancy by current political status during the 1950-2010 period. We assessed whether decolonization coincided with life expectancy trend changes by: 1. calculating the annual changes before and after independence, and 2. evaluating trend breaks in a predefined period during decolonization using joinpoint analyses. Similar analyses were undertaken for GDP per capita. Life expectancy in currently sovereign Caribbean states was already lower than in affiliated states before political independence. Overall, decolonization coincided with reductions in life expectancy growth, but not with reductions in economic growth, and changes in life expectancy growth in the decade after independence did not correspond with changes in economic performance. The widening of the life expectancy gap between currently sovereign and affiliated states accelerated in the 1990's and continues to increase. Despite considerable life expectancy gains in all Caribbean states, life expectancy in currently sovereign states increasingly lags behind that of states which remained affiliated. Our results indicate that changing economic conditions were not the main determinant of the unfavorable trends in life expectancy during and after decolonization. Circumstantial evidence points to the weakening of bureaucracies during decolonization underlying the uneven life expectancy developments of currently affiliated and sovereign states.


Assuntos
Produto Interno Bruto/tendências , Expectativa de Vida/tendências , Região do Caribe , Humanos , Fatores Socioeconômicos
14.
Sci Adv ; 2(1): e1501104, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26844299

RESUMO

We report the first observation of exciplex state electroluminescence due to carrier injection between the hybrid lead halide perovskite (MAPbI3-xClx) and quantum dots (core/shell PbS/CdS). Single layers of perovskite (PS) and quantum dots (QDs) have been produced by solution processing methods, and their photoluminescent properties are compared to those of bilayer samples in both PS/QD and QD/PS configurations. Exciplex emission at lower energies than the band gap of both PS and QD has been detected. The exciplex emission wavelength of this mixed system can be simply tuned by controlling the QD size. Light-emitting diodes (LEDs) have been fabricated using those configurations, which provide light emission with considerably low turn-on potential. The "color" of the LED can also be tuned by controlling the applied bias. The presence of the exciplex state PS and QDs opens up a broad range of possibilities with important implications not only in tunable LEDs but also in the preparation of intermediate band gap photovoltaic devices with the potentiality of surpassing the Shockley-Queisser limit.


Assuntos
Compostos de Cálcio/química , Nanotecnologia/instrumentação , Óxidos/química , Pontos Quânticos/química , Titânio/química , Cor , Eletroquímica/instrumentação , Luz , Luminescência
15.
Philos Trans A Math Phys Eng Sci ; 373(2055)2015 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-26460110

RESUMO

The episodic formation, consolidation and breakdown of preindustrial states occurred in multiple contexts worldwide during the last 5000 years and are contingent upon interacting endogenous economic, demographic and political mechanisms. In some instances, there is support for climate change stimulating integration or inducing sociopolitical fragmentation in these complex systems. Here, we build upon this paradigm and introduce the hypothesis that stable climatic conditions favour the formation of agrarian states, while persistently volatile climatic conditions can contribute to the episodic collapse of these complex societies. It is generally recognized that agrarian economies underwrite preindustrial state-level societies. In these contexts, the economic uncertainty associated with highly volatile climatic regimes makes it difficult for individuals or institutions to determine the costs and benefits of one agricultural strategy over another. We argue that this fosters sociopolitical instability and decentralization. As a first test of this hypothesis, we examine the historical dynamics of state formation and decline in the Mexican and Andean highlands within the last 2000 years. The available data in these regions are consistent with the hypothesis that the formation and consolidation of regional polities and empires is favoured in stable climatic regimes and that political decentralization can be stimulated and perpetuated by highly volatile climatic conditions.

16.
Macromol Rapid Commun ; 36(11): 1122-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25923668

RESUMO

The exciton dynamics in pristine films of two structurally related low-bandgap diketopyrrolopyrrole (DPP)-based donor-acceptor copolymers and the photophysical processes in bulk heterojunction solar cells using DPP copolymer:PC71 BM blends are investigated by broadband transient absorption (TA) pump-probe experiments covering the vis-near-infrared spectral and fs-µs dynamic range. The experiments reveal surprisingly short exciton lifetimes in the pristine poly-mer films in conjunction with fast triplet state formation. An in-depth analysis of the TA data by multivariate curve resolution analysis shows that in blends with fullerene as acceptor ultrafast exciton dissociation creates charge carriers, which then rapidly recombine on the sub-ns timescale. Furthermore, at the carrier densities created by pulsed laser excitation the charge carrier recombination leads to a substantial population of the polymer triplet state. In fact, virtually quantitative formation of triplet states is observed on the sub-ns timescale. However, the quantitative triplet formation on the sub-ns timescale is not in line with the power conversion efficiencies of devices indicating that triplet state formation is an intensity-dependent process in these blends and is reduced under solar illumination conditions, as free charge carriers can be extracted from the photoactive layer in devices.


Assuntos
Fulerenos/química , Polímeros/química , Energia Solar , Cetonas/química , Pirróis/química , Espectrofotometria Ultravioleta
17.
Am J Phys Anthropol ; 156(3): 305-16, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25360793

RESUMO

The Samnites were an Iron Age population that shifted from warlike mountain dwellers to the largest sociopolitical unit of central Italy, able to dispute with Rome the domination over the peninsula. Archaeological and historical evidence suggests that this major shift in the scale of conflict may have involved a reorganization of the military system, which changed from an elite militia to a conscript or standing army from the Orientalizing-Archaic (800-500 BC) to Hellenistic times (400-27 BC). We propose a bioarchaeological framework jointly analyzing skeletal properties and funerary treatment in male Samnites to investigate on this shift in military organization. We anticipated that, when Samnites had an elite militia, the warring force was constituted by the wealthier segments of the society. Conversely, we expected the warring force of the standing/conscript army to be mainly drawn from the lower social strata. We considered high asymmetry in J, a measure of humeral torsional rigidity (calculated via cross-sectional geometry, CSG) as a proxy for pre- and peri-adolescent-onset weapon training. The social standing of the individual was approximated via funerary treatment analysis (Status Index). Results show that in the Orientalizing-Archaic period, humeral asymmetry and Status Index are positively correlated, and the high-status subsample shows significantly higher asymmetry than the low-status subsample. Among Hellenistic Samnites, no correlation between Status Index and humeral asymmetry is present, and the low-status subsample is the most lateralized. Results support the use of CSG in a strong theoretical framework to investigate past changes in military organization and their correlates in terms of sociopolitical development, alterations of power relationships, and warfare.


Assuntos
Arqueologia/métodos , Militares/história , Militares/estatística & dados numéricos , História Antiga , Humanos , Úmero/anatomia & histologia , Itália , Masculino , Mundo Romano
18.
Mycobiology ; 37(4): 247-50, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23983543

RESUMO

Twenty-five isolates of Fusarium fujikuroi acquired from rice seeds and rice plants evidencing symptoms of Bakanae disease were evaluated to determine their mating types and characterize the formation of their sexual state. The mating types of the isolates were evaluated via multiplex PCR with the diagnostic primers of the mating-type (MAT) region: GFmat1a, GFmat1b, GFmat2c, and GFmat2d. Among the 25 isolates, 11 were identified as MAT-1 (male), and 14 as MAT-2 (female). Four MAT-1 isolates and three MAT-2 isolates were mated and cultured to evaluate the optimal culture conditions for the production of their sexual states. Among four tested media, 10% V8 juice agar proved optimal for the perithecial production of the isolates. The isolates also generated the largest numbers of perithecia when incubated at 23℃ in alternating cycles of 12 hr fluorescent light and NUV fluorescent light and 12 hr darkness.

19.
Mycobiology ; : 247-250, 2009.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-729437

RESUMO

Twenty-five isolates of Fusarium fujikuroi acquired from rice seeds and rice plants evidencing symptoms of Bakanae disease were evaluated to determine their mating types and characterize the formation of their sexual state. The mating types of the isolates were evaluated via multiplex PCR with the diagnostic primers of the mating-type (MAT) region: GFmat1a, GFmat1b, GFmat2c, and GFmat2d. Among the 25 isolates, 11 were identified as MAT-1 (male), and 14 as MAT-2 (female). Four MAT-1 isolates and three MAT-2 isolates were mated and cultured to evaluate the optimal culture conditions for the production of their sexual states. Among four tested media, 10% V8 juice agar proved optimal for the perithecial production of the isolates. The isolates also generated the largest numbers of perithecia when incubated at 23degrees C in alternating cycles of 12 hr fluorescent light and NUV fluorescent light and 12 hr darkness.


Assuntos
Ágar , Escuridão , Fusarium , Luz , Reação em Cadeia da Polimerase Multiplex , Sementes
20.
Dados rev. ciênc. sociais ; 51(1): 239-260, 2008.
Artigo em Português | LILACS | ID: lil-484641

RESUMO

This paper deals with the impact of war on state formation in Ireland and England, focusing on the period from 1590 to 1691, the key turning point for the future development of the state in both countries. War played a vital role, but in a number of different ways, including in the ideological sphere, in a complex process, rather than simply causing a long-term expansion in army size and subsequent growth of the state. The author further emphasizes the dynamic nature of the state itself.


Dans cet article, on étudie l'impact de la guerre sur la formation de l'État en Irlande et en Angleterre, surtout dans la période de 1590 à 1691, période-clé pour le développement de l'État dans ces deux pays. La guerre y a joué un rôle très important sous plusieurs formes, et en particulier dans la sphère idéologique, au long d'un processus très complexe, au-delà de son rôle d'expansion et d'augmentation des armées et de sa conséquence, la croissance de l'État, dont il faut souligner la nature dynamique.

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