Raman spectra of p-cresol, a model compound for tyrosine, were measured in solutions of various solvents, paying special attention to the effects of hydrogen bonding on the Raman bands in the 1300-1150 cm-' region. The frequency of the v,,,. (C-O stretch) band was found to be sensitive to the state of hydrogen bonding at the phenolic hydroxyl group. It occurs at 1275-1265 cm-' in protondonating states, 1240-1230 cm-' in proton-accepting states and around 1255 cm-' in weakly or non-hydrogen-bonding states. This relationship between the v7,,. frequency and hydrogen bonding was verified in the Raman spectra of L-tyrosine and its derivatives in the crystalline state. Analysis of the crystal Raman spectra further suggested that the v7,, (C-C stretch) frequency also serves as a marker, though less sensitive, of hydrogen bonding and the v9,, (C-H bend) frequency reflects the displacement of the OH hydrogen atom from the plane of benzene ring, which may be induced by hydrogen bonding. These Raman bands are strong with UV excitation and are expected to be useful in characterizing tyrosine side-chains in peptides and proteins by UV resonance Raman spectroscopy.

URL: http://www.umin.ac.jp/ctr/index/htm/ Unique identifier: UMIN000007109.

No abstract

A survey of oligotrophic Lake Rara, the biggest lake in Nepal, was carried out from 1982 till 1984. Mean depth is 100 m, and maximum depth is 167 m. The surface area covers 9.8 km2, and the lake contains 0.98 km3 volume of water.Transparency was about 16 m, photoquantum yield decreased exponentially with depth below 5 m, and the extinction coefficient was 8.3 x 10m2. The concentration of Chl.-a was in the range of 0.06-0.46 mg me3, and total nitrogen was 18-30 pg 1-l. The whole water column was well oxygenated. Primary productivity was extremely low. It has more than 30 inflowing brooks and one outlet. The water quality of the brooks changes drastically with their location. The pH, electrical conductivity, and EDTA hardness in the waters from a landslide area were high. In the waters from a rich pine forest they were extremely low.The zooplankton consisted of two species of protozoa, five species of rotifers, two species of Cladocera, and two species of Copepoda. The zooplankton density range was 6200-16200 individuals mv3. The minimum was on November llth, 1983 and the maximum on August 19th, 1983.

No abstract

d concentrated colony of Fragilaria erotonensis collected from the surface water of Lake Suwa, which is one of the typical eutrophic lakes in Japan, and organic matter contained in untreated surface water from the same lake were subjected to aerobic decomposition by bacteria in a dark room at a temperature of 2 0 5 3 OC. An exponential increase of urea with time was recorded in both of the experiments. The apparent rate constants of ureiL production were calculated t o be 0.083 day-1 for decomposition of F. crotonensis and 0.051 day-1 for decomposition of thc organic matter contained in the untreated surface water.This study suggests that urea production by bacterial decomposition of organic matter, including phytoplankton, may be a n important source of urea in natural waters under certain conditions.

BackgroundPoor response to diuretics is associated with worse prognosis in patients with acute heart failure (AHF). We hypothesized that treatment with tolvaptan improves diuretic response in patients with AHF.MethodsWe performed a secondary analysis of the AQUAMARINE open-label randomized study in which a total of 217 AHF patients with renal impairment (eGFR < 60 mL/min/1.73 m2) were randomized to either tolvaptan or conventional treatment. We evaluated diuretic response to 40 mg furosemide or its equivalent based on two different parameters: change in body weight and net fluid loss within 48 h.ResultsThe mean time from patient presentation to randomization was 2.9 h. Patients with a better diuretic response showed greater relief of dyspnea and less worsening of renal function. Tolvaptan patients showed a significantly better diuretic response measured by diuretic response based both body weight [−1.16 (IQR −3.00 to −0.57) kg/40 mg vs. −0.51 (IQR −1.13 to −0.20) kg/40 mg; P < 0.001] and net fluid loss [2125.0 (IQR 1370.0–3856.3) mL/40 mg vs. 1296.3 (IQR 725.2–1726.5) mL/40 mg; P < 0.001]. Higher diastolic blood pressure and use of tolvaptan were independent predictors of a better diuretic response.ConclusionsBetter diuretic response was associated with greater dyspnea relief and less WRF. Early treatment with tolvaptan significantly improved diuretic response in AHF patients with renal dysfunction.Electronic supplementary materialThe online version of this article (doi:10.1007/s00392-017-1122-1) contains supplementary material, which is available to authorized users.

The abundance, growth, and grazing loss rates of picophytoplankton were investigated in August 2002 in Barguzin Bay, Lake Baikal. Water samples for incubation were taken once at a near-shore station and twice at an offshore station. Contributions of picophytoplankton to total phytoplankton were high (56.9-83.9%) at the offshore station and low (5.8-6.8%) at the near-shore station. The picophytoplankton community in the offshore station comprised mainly phycoerythrin (PE)-rich cyanobacteria, with eukaryotic picophytoplankton being less abundant. In contrast, as well as PE-rich cyanobacteria and eukaryotic picophytoplankton, phycocyanin (PC)-rich cyanobacteria were found in the near-shore station. At the offshore station, growth and grazing loss rates on 25 August were 0.56 and 0.43 day )1 , respectively, and on 29 August, 0.69 and 0.83 day )1 , respectively. At the near-shore station, growth and grazing loss rates were 1.61 and 0.70 day )1 , respectively. These results show that there is a difference in the abundance, composition, and ecological role in the microbial food web of picophytoplankton between the near-shore and the offshore areas in Barguzin Bay.