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An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract Cells of the cyanobacterium Synechococcus 6301 were grown under illumination whose spectral composition favoured absorption either by the phycobilisome (PBS) light-harvesting antenna of photosystem II (PS II) or by the chlorophyll (Chi) a light-harvesting antenna of photosystem I (PS I). Cells grown under PS I-light developed relatively high PS II/PS I and PBS/Chl ratios. Cells grown under PS II-light developed relatively low PS II/PS I and PBS/Chl ratios. Thus, the primary difference between cells in the two acclimation states appeared to be the relative concentration of PBS-PS II and PS I complexes in the thylakoid membrane. Measurements of the quantum yield of oxygen evolution suggested a higher efficiency of cellular photosynthesis upon the adjustment of photosystem stoichiometry to a specific light condition. The quantum yield of oxygen evolution was nevertheless lower under PBS than Chi excitation, suggesting quenching of excitation energy in the photochemical apparatus of PS II in Synechococcus 6301. This phenomenon was more pronounced in the PS II-light than in the PS I-light grown cells. Room temperature and 77 K fluorescence emission spectroscopy indicated that excess excitation energy in the PBS was not transferred to PS I, suggesting the operation of a non-radiative and non-photochemical decay of excitation energy at the PBS-PS II complex. This non-photochemical quenching was specific to conditions where excitation of PS II occurred in excess of its capacity for useful photochemistry.
Abstract Duchenne muscular dystrophy (DMD) results in a progressive loss of functional skeletal muscle mass (MM) and replacement with fibrofatty tissue. Accurate evaluation of MM in DMD patients has not previously been available. Our objective was to measure MM using the D 3 creatine (D 3 Cr) dilution method and determine its relationship with strength and functional capacity in patients with DMD over a wide range of ages. Subjects were recruited for participation in a 12 month, longitudinal, observational study. Here, we report the baseline data. A 20 mg dose of D 3 Cr dissolved in water was ingested by 92 patients with DMD (ages 4–25 years) followed later with a fasting urine sample. Enrichment of D 3 creatinine was determined by liquid chromatography‐mass spectrometry analysis. The North Star Ambulatory Assessment (NSAA) total score was determined for ambulatory participants, and the Performance of Upper Limb (PUL 2.0) total score and grip strength for all participants. We observed a significant age‐associated increase in body weight along with a substantial decrease in MM/body weight (%MM). MM and %MM were associated with PUL score ( r = 0.517, P < 0.0001 and r = 0.764, P < 0.0001 respectively). The age‐associated decrease in MM and %MM was strongly associated with ambulatory status. We observed very little overlap in %MM between ambulant and non‐ambulant subjects, suggesting a threshold of 18–22% associated with loss of ambulation. MM is substantially diminished with advancing age and is highly related to clinically meaningful functional status. The D 3 Cr dilution method may provide a biomarker of disease progression and therapeutic efficacy in patients with DMD or other neuromuscular disorders. image Key points The non‐invasive D 3 creatine dilution method provides novel data on whole body functional muscle mass (MM) in a wide range of ages in patients with DMD and reveals profoundly low functional MM in older non‐ambulant patients. The difference in %MM between ambulant and non‐ambulant subjects suggests a threshold for loss of ambulatory ability between 18 and 22% MM. The data suggest that as functional MM declines with age, maintaining a lower body weight may help to conserve ambulatory ability.
Habitat use and food web linkages are critical data for fish conservation and habitat restoration efforts, particularly for threatened salmonids species. Otolith microchemistry has been shown to be a powerful tool for reconstructing fish movement, but over small distances (kilometers), geology-derived differences in otolith chemistry are rare. Here, we demonstrate that otolith {sup 13}C/{sup 12}C ratio (i.e. {delta}{sup 13}C) of anadromous steelhead trout can be used to distinguish residence in small streams from residence in larger streams and rivers. While previous research has shown that water dissolved inorganic carbon {delta}{sup 13}C is the primary source of carbon in otoliths, the downstream change in food {delta}{sup 13}C in this watershed appears to be the primary control on otolith {delta}{sup 13}C. As a result, this method can also be applied to the problem of reconstructing feeding history at a location.
The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen's structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments.
Organizations increasingly need to collaborate by performing a computation on their combined dataset, while keeping their data hidden from each other. Certain kinds of collaboration, such as collaborative data analytics and AI, require a level of performance beyond what current cryptographic techniques for distributed trust can provide. This is because the organizations run software in different trust domains, which can require them to communicate over WANs or the public Internet. In this paper, we explore how to instead run such applications using fast datacenter-type LANs. We show that, by carefully redesigning distributed trust frameworks for LANs, we can achieve up to order-of-magnitude better performance than naïvely using a LAN. Then, we develop deployment models for Distributed But Proximate Trust (DBPT) that allow parties to use a LAN while remaining physically and logically distinct. These developments make secure collaborative data analytics and AI significantly more practical and set new research directions for developing systems and cryptographic theory for high-performance distributed trust.
Abstract Grand canonical ensemble Monte Carlo (GCMC) simulatios of methane in the zeolite silicalite have been used to predict adsorption isotherms over a wide range of occupancies at several temperatures. The zeolite has been modeled using a detailed atomistic description, as have the methane molecules. Lennard-Jones parameters for the atomic interactions have been taken from the literature. Adsorption isotherms and heats of sorption have been predicted in good agreement with experiment. Structural features of the intracrystalline fluid have also been studied. In a complementary study, the test particle insertion method has been used to generate isotherms from molecular dynamics simulations. The results are in excellent agreement with those from GCMC.
