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We have used ≈ 40 fs pulses from a Ti:Sa laser to investigate the ultrafast energy transfer and relaxation dynamics in the LH1 and LH2 light-harvesting pigment-proteins of photosynthetic purple bacteria. Our results reveal a new feature, not earlier observed in light-harvesting pigments, ultrafast relaxation characterized by a time constant of approximately 20 fs, which we interpret as interexcito
Picosecond spectrally resolved fluorescent measurements together with the coupled kinetic rate equation model simulations of the data have been employed to determine the rates and pathways of heterogeneous excitation transport in the membranes of photosynthetic bacteria Rhodobacter sphaeroides and Chromatium minutissimum. Excitation transport from bacteriochlorophyll molecules B800 to B850, belong
A spectroscopic characterization of the chlorophyll a (Chl) molecule in the monomeric cytochrome b6f complex (Cytb6f) isolated from the cyanobacterium Synechocystis PCC6803 is presented. The fluorescence lifetime and quantum yield have been determined, and it is shown that Chl in Cytb6f has an excited-state lifetime that is 20 times smaller than that of Chl in methanol. This shortening of the Chl
The temperature dependence of absorption and selectively excited fluorescence spectra of B820 subunit of the bacterial light-harvesting antenna is modelled by using the impurity center theory ofoptical spectra. In order toget acceptable agreement between theory and experiment, we suggest that due to the dimeric nature of B820, the electronic transition is weakly coupled to a rather broad distribut
The picosecond time-domain singlet excitation transfer and trapping kinetics in photosynthetic membranes in case of low excitation intensities is studied by numerical integration of the appropriate master equation. The essential features of our two-dimensional-lattice random walk model are spectral heterogeneity of the light-harvesting antenna, inclusion of temperature effects, nonabsolute excitat
Polarized, site-selected fluorescence was measured for light-harvesting complex II (LHCII), the major Chl a/b/xanthophyll binding light-harvesting complex of green plants. Upon selective excitation in the range of 679-682 nm at 4 K, separate zero-phonon lines and phonon wings could be observed, as well as sharp lines in the vibronic region of the emission: vibronic zero-phonon lines. The maximum o
We investigated the exciton transfer dynamics in photosynthetic light-harvesting complex 2 (LH2) coupled to an optical microcavity. Using computational simulations based on Redfield theory, we analyzed how microcavity coupling influences energy relaxation and transfer within and between LH2 aggregates. Our results show that the exciton transfer rate between B850 rings follows a square dependence o
Absorption bands of photosynthetic and other biological pigment-protein complexes undergo dramatic variations in position and shape upon changing the temperature. In this paper we have reviewed a calculation algorithm to simulate the temperature dependence of electronic spectra coupled to any number of vibrations with arbitrary coupling strength. A number of computer simulations is carried out in
This article critically examines the role of lawyers in addressing the complex legal and ethical challenges posed by climate change, as highlighted in Professor Abel's work. It explores the intricate interplay between evolving knowledge paradigms and the democratic processes that lawyers must navigate when confronting environmental issues. Central to the discussion is the need for a clear ethical
We consider the Boussinesq equation on the line for a broad class of Schwartz initial data relevant for water waves. In a recent work, we identified ten main sectors describing the asymptotic behavior of the solution, and for each of these sectors we gave an exact expression for the leading asymptotic term in the case when no solitons are present. In this paper, we derive an asymptotic formula in
Sedimentary concentrations of redox-sensitive trace metals are widely used to reconstruct past ocean redox conditions. Vanadium (V) has great potential as a (paleo)redox proxy, due to its strong redox-dependent speciation (+III, +IV, +V) and the increased sedimentary sequestration of its more reduced species. The geochemistry of V in sulfide-rich marine environments is not yet well understood, how
Background World economies increasingly rely on non-standard employment arrangements, which has been linked to ill health. While work and employment conditions are recognized structural determinants of health and health equity, policies aiming to protect workers from negative implications predominantly focus on standard employment arrangements and the needs of workers in non-standard employment ma
The rate of colorectal anastomotic leakage has remained unchanged for the last decades. The limitations of current anastomotic methods have generated an interest in alternative anastomotic techniques, such as compression anastomosis. The aim of this experimental study was to evaluate the early mechanical strength in left colonic anastomoses, comparing C-REX LapAid and circular stapled anastom
This paper investigates how verbal affixes that encode manner information (manner affixes) interact with verbs of different lexical aspect classes and transitivity values in West Greenlandic (Inuit–Yupik–Unangan: Greenland). Manner affixes remain an understudied and poorly understood grammatical category. The data presented and discussed here is primarily based on original fieldwork conducted in C
Despite being the leading cause of death worldwide, cancer still lacks precise biomarkers for effective targeting, limiting efforts to reduce mortality rates. This review explores the role and clinical significance of a newly identified long non-coding RNA, MYOSLID, in cancer progression. MYOSLID has emerged as a critical modulator in cancer progression by influencing key hallmarks such as prolife
The exponential increase in medical waste production has increased the difficulty of waste management, resulting in higher medical waste dispersion into the environment. By employing a circular economy approach, it is possible to develop new materials by waste valorization. The employment of biodegradable and renewable agro-food, waste-derived materials may reduce the environmental impact caused b
The catalytic activity of the binuclear glyoxalase II (GlxII) enzyme is closely linked to the type and charge of metal ions in its active site. Using hybrid quantum mechanics/molecular mechanics (QM/MM) calculations, we investigated the reaction mechanism of human GlxII, which features two Zn(ii) ions in its active site. By systematically replacing these Zn(ii) ions with Fe(ii), Fe(iii), or Co(ii)
A series of molecular alloys of 1,2,4,5-tetrabromobenzene and 1,2,4,5-tetrachlorobenzene with varying compositions were prepared in an attempt to obtain jumping crystals with adjustable temperature of thermosalient phase transition. Molecular alloys were studied with a combination of thermal and structural techniques (DSC, SCXRD, XRPD, hot-stage microscopy). Alloys with a high 1,2,4,5-tetrabromobe
Ambient pressure X-ray photoelectron spectroscopy (APXPS) combined with the dip-and-pull method can be used for operando studies of electrochemical systems. A complete coupling between the spectroscopic and the electrochemical measurements is generally challenging due to an inherent difference between the meniscus and the bulk electrolyte - the mass transport. This work investigates meniscus mass
