Resonant Vibrational Enhancement of Downhill Energy Transfer in the -Phycocyanin Chromophore Dimer.

Energy transfer between electronically coupled photosynthetic light-harvesting antenna pigments is frequently assisted by protein and chromophore nuclear motion. This energy transfer mechanism usually occurs in the weak or intermediate system-bath coupling regime. Redfield theory is frequently used to describe the energy transfer in this regime.

Soft X-ray spectromicroscopic proof of a reversible oxidation/reduction of microbial biofilm structures using a novel microfluidic in situ electrochemical device.

In situ electrochemistry on micron and submicron-sized individual particles and thin layers is a valuable, emerging tool for process understanding and optimization in a variety of scientific and technological fields such as material science, process technology, analytical chemistry, and environmental sciences. Electrochemical characterization and manipulation coupled with soft X-ray spectromicroscopy helps identify, quantify, and optimize processes in complex systems such as those with high heterogeneity in the spatial and/or temporal domain. Here we present a novel platform optimized for in situ electrochemistry with variable liquid electrolyte flow in soft X-ray scanning transmission X-ray microscopes (STXM).

Single-Molecule Detection of the Encounter and Productive Electron Transfer Complexes of a Photosynthetic Reaction Center.

Small, diffusible redox proteins play an essential role in electron transfer (ET) in respiration and photosynthesis, sustaining life on Earth by shuttling electrons between membrane-bound complexes via finely tuned and reversible interactions. Ensemble kinetic studies show transient ET complexes form in two distinct stages: an "encounter" complex largely mediated by electrostatic interactions, which subsequently, through subtle reorganization of the binding interface, forms a "productive" ET complex stabilized by additional hydrophobic interactions around the redox-active cofactors. Here, using single-molecule force spectroscopy (SMFS) we dissected the transient ET complexes formed between the photosynthetic reaction center-light harvesting complex 1 (RC-LH1) of and its native electron donor cytochrome (cyt ).

Sulfoquinovosyl diacylglycerol is required for dimerisation of the Rhodobacter sphaeroides reaction centre-light harvesting 1 core complex.

The reaction centre-light harvesting 1 (RC-LH1) core complex is indispensable for anoxygenic photosynthesis. In the purple bacterium Rhodobacter (Rba.) sphaeroides RC-LH1 is produced both as a monomer, in which 14 LH1 subunits form a C-shaped antenna around 1 RC, and as a dimer, where 28 LH1 subunits form an S-shaped antenna surrounding 2 RCs.

Teratogenicity of zonisamide and other little-used antiseizure medications.

Purpose: To investigate the risk of teratogenesis occurring in relation to intrauterine exposure to infrequently used antiseizure medications in Australia.

Methods: Analysis of data contained in the Raoul Wallenberg Australian Pregnancy Register of Antiepileptic Drugs.

Results: There was statistically significant evidence that zonisamide, but not any other of nine infrequently used antiseizure medications in Australia, was associated with a risk of teratogenesis related to the maternal dose of the drug taken in at least the earlier half of pregnancy.

Generalized biomolecular modeling and design with RoseTTAFold All-Atom.

Deep-learning methods have revolutionized protein structure prediction and design but are presently limited to protein-only systems. We describe RoseTTAFold All-Atom (RFAA), which combines a residue-based representation of amino acids and DNA bases with an atomic representation of all other groups to model assemblies that contain proteins, nucleic acids, small molecules, metals, and covalent modifications, given their sequences and chemical structures. By fine-tuning on denoising tasks, we developed RFdiffusion All-Atom (RFdiffusionAA), which builds protein structures around small molecules.

Pregnancy, antiseizure medications and unexplained intrauterine foetal death.

Objective: To assess the role of antiseizure medication (ASM) regimens and other factors in relation to the occurrence of intrauterine foetal death (IUFD) in pregnant women with epilepsy (WWE) enrolled in the Raoul Wallenberg Australian Pregnancy Register of Antiepileptic Drugs (APR).

Results: IUFDs occurred in 70 (3.01 %) of 2,323 prospective pregnancies from WWE with known outcomes in the APR.

The teratogenesis risk associated with antiseizure medication duotherapy in women with epilepsy.

Purpose: To investigate rates of occurrence of pregnancies associated with a foetal malformation (FM pregnancy rates) following simultaneous intrauterine exposure to two antiseizure medications in 524 pregnancies in women with epilepsy from the Australian Pregnancy Register who were treated simultaneously with various combinations and dosages of two antiseizure medications (duotherapy).

Results: FM pregnancy rates tended to be higher in those exposed simultaneously to two antiseizure medications, each of which was a statistically significant teratogen (valproate, topiramate, or carbamazepine), than when there was exposure to only one such teratogen. When there was exposure to only one such teratogen together with clonazepam or levetiracetam, for neither of which there was statistically significant evidence of heightened teratogenicity, the FM pregnancy rates also tended to be higher, but less so.

Impact of a Pharmacist-Conducted Preoperative Beta-Lactam Allergy Assessment on Perioperative Cefazolin Prescribing.

Cefazolin is guideline recommended for perioperative prophylaxis in orthopedic surgery. Despite its unique R1 side chain, cefazolin is often avoided in patients with beta-lactam allergy with concern for cross reactivity. The primary outcome was the percentage of patients who received cefazolin perioperatively.

Studies of Copper-Based CO Reduction Electrocatalysts by Scanning Transmission Soft X-ray Microscopy.

A microfluidic-enabled electrochemical device has been developed to investigate electrochemically active nanomaterials under reaction conditions using scanning transmission soft X-ray microscopy (STXM). STXM measurements were conducted on electrodeposited Cu catalysts under electrochemical CO reduction (COR) conditions. The study provides detailed, quantitative results about the changes in the morphology and chemical structure of the catalytic nanoparticles as a function of applied potentials.

Lenacapavir: A novel injectable HIV-1 capsid inhibitor.

Patients living with multidrug-resistant (MDR) HIV have limited antiretroviral regimen options that provide durable viral suppression. Lenacapavir is a novel first-in-class inhibitor of HIV-1 capsid function with efficacy at various stages of the viral life cycle, and it is indicated for the treatment of MDR HIV-1 infection in combination with optimized background antiretroviral therapy. The favourable pharmacokinetic profile supports an every sixth month dosing interval of subcutaneous lenacapavir after an initial oral loading dose, which may advocate for continued adherence to antiretroviral therapy (ART) through the reduction of daily pill burden.

Changes over 24 years in a pregnancy register - Teratogenicity and epileptic seizure control.

Objectives: To trace (i) changes in Australian Pregnancy Register (APR) records concerning antiseizure medications (ASMs) prescribed for women with epilepsy (WWE) over the course of 24 years and correlate the changes with (ii) rates of occurrence of pregnancies involving foetal malformations, (iii) the body organs involved in the malformations, and (iv) freedom from epileptic seizures.

Results: Use of valproate and carbamazepine decreased progressively, use of lamotrigine remained relatively static, and the use of levetiracetam increased progressively, whereas the use of topiramate first increased and then fell again, associated with a temporary increase in malformation-associated pregnancy rate. More serious malformations, such as spina bifida, became less frequent, whereas more trivial ones tended to increase, whereas epileptic seizure freedom rates improved.

The Influence of Transcranial Alternating Current Stimulation on Fatigue Resistance.

Previous research has shown that some forms of non-invasive brain stimulation can increase fatigue resistance. The purpose of this study is to determine the influence of transcranial alternating current stimulation (tACS) on the time to task failure (TTF) of a precision grip task. The study utilized a randomized, double-blind, SHAM-controlled, within-subjects design.

Twisted Carotenoids Do Not Support Efficient Intramolecular Singlet Fission in the Orange Carotenoid Protein.

Singlet exciton fission is the spin-allowed generation of two triplet electronic excited states from a singlet state. Intramolecular singlet fission has been suggested to occur on individual carotenoid molecules within protein complexes provided that the conjugated backbone is twisted out of plane. However, this hypothesis has been forwarded only in protein complexes containing multiple carotenoids and bacteriochlorophylls in close contact.

Phycobilisome's Exciton Transfer Efficiency Relies on an Energetic Funnel Driven by Chromophore-Linker Protein Interactions.

The phycobilisome is the primary light-harvesting antenna in cyanobacterial and red algal oxygenic photosynthesis. It maintains near-unity efficiency of energy transfer to reaction centers despite relying on slow exciton hopping along a relatively sparse network of highly fluorescent phycobilin chromophores. How the complex maintains this high efficiency remains unexplained.

Soft X-ray spectro-ptychography of boron nitride nanobamboos, carbon nanotubes and permalloy nanorods.

Spectro-ptychography offers improved spatial resolution and additional phase spectral information relative to that provided by scanning transmission X-ray microscopes. However, carrying out ptychography at the lower range of soft X-ray energies (e.g.

The structure and assembly of reaction centre-light-harvesting 1 complexes in photosynthetic bacteria.

Chlorophototrophic organisms have a charge-separating reaction centre (RC) complex that receives energy from a dedicated light-harvesting (LH) antenna. In the purple phototrophic bacteria, these two functions are embodied by the 'core' photosynthetic component, the RC-LH1 complex. RC-LH1 complexes sit within a membrane bilayer, with the central RC wholly or partly surrounded by a curved array of LH1 subunits that bind a series of bacteriochlorophyll (BChl) and carotenoid pigments.

Specific fetal malformations following intrauterine exposure to antiseizure medication.

Objective: To investigate in the Australian Pregnancy Register of Antiepileptic Drugs patterns of fetal malformation associated with intrauterine exposure to particular currently available antiseizure medications taken by women with epilepsy.

Results: There was statistically significant evidence (P < 0.05) of an increased hazard of fetal malformation associated with exposure to valproate, carbamazepine, topiramate, zonisamide, and with conception after assisted fertilization, but a reduced hazard in the offspring of women who continued to smoke during pregnancy.

Photosynthesis in the near infrared: the γ subunit of Blastochloris viridis LH1 red-shifts absorption beyond 1000 nm.

The reaction centre (RC) in purple phototrophic bacteria is encircled by the primary light-harvesting complex 1 (LH1) antenna, forming the RC-LH1 'core' complex. The Qy absorption maximum of LH1 complexes ranges from ∼875-960 nm in bacteriochlorophyll (BChl) a-utilising organisms, to 1018 nm in the BChl b-containing complex from Blastochloris (Blc.) viridis.

Cryo-EM structure of the four-subunit cytochrome complex in styrene maleic acid nanodiscs.

Cytochrome complexes are ubiquinol:cytochrome oxidoreductases, and as such, they are centrally important components of respiratory and photosynthetic electron transfer chains in many species of bacteria and in mitochondria. The minimal complex has three catalytic components, which are cytochrome , cytochrome , and the Rieske iron-sulfur subunit, but the function of mitochondrial cytochrome complexes is modified by up to eight supernumerary subunits. The cytochrome complex from the purple phototrophic bacterium   has a single supernumerary subunit called subunit IV, which is absent from current structures of the complex.

Cysteine Biosynthesis in : Substrate Specificity of CysM and the Dualism of Sulfide.

is a highly successful enteric pathogen with a small, host-adapted genome (1.64 Mbp, ~1650 coding genes). As a result, has limited capacity in numerous metabolic pathways, including sulfur metabolism.

Absolute quantification of cellular levels of photosynthesis-related proteins in Synechocystis sp. PCC 6803.

Quantifying cellular components is a basic and important step for understanding how a cell works, how it responds to environmental changes, and for re-engineering cells to produce valuable metabolites and increased biomass. We quantified proteins in the model cyanobacterium Synechocystis sp. PCC 6803 given the general importance of cyanobacteria for global photosynthesis, for synthetic biology and biotechnology research, and their ancestral relationship to the chloroplasts of plants.