Investigation of hydrogen bonds in proton transfer complexes derived from the reaction of 2- and 4-(N,N-dimethylamino)pyridines with chloranilic acid.

New complexes of 2-(N,N-dimethylamino)pyridine with chloranilic acid (2-DMAP + CLA) and 4-(N,N-dimethylamino)pyridine with chloranilic acid (4-DMAP + CLA) were synthesized and characterized by single crystal X-ray diffraction, infrared spectroscopy, thermal analysis methods and 1H, 13C and 15N NMR spectroscopy. The NMR spectroscopies were carried out in both, DMSO solution and in the solid state (CPMAS NMR). The 2-DMAP + CLA and 4-DMAP + CLA complexes crystallize in centrosymmetric P-1 and P21/c space group, respectively. In both complexes, the phenomenon of proton transfer is observed, which results in the formation of strong N+-H···O- hydrogen bonds. Thermal decompositions of 2-DMAP + CLA and 4-DMAP + CLA complexes were studied by thermogravimetric analysis. Temperature dependent IR spectra revealed that methyl groups of 4-DMAP + CLA perform fast stochastic reorientational motion at room temperature which is slowed on cooling while in 2-DMAP + CLA reonrientational motion of CH3 groups is much slower due to steric effects.

Low temperature investigations of dynamic properties in l-leucine - chloranilic acid complex.

Inelastic neutron scattering (INS) and infra-red (IR) spectroscopy methods were used for determination of dynamic structure of l-leucine - chloranilic acid complex. A theoretical dynamic pattern calculated by the density functional theory (DFT) method for periodic boundary conditions accompanied the experimental ones. Normal modes in the vibrational spectra were defined and described. The characteristic presence of the Hadzi's trio enriched by numerous submaxima is observed in the wavenumber range 3200-800 cm-1. Bands assigned to CH3 torsion vibrations in the leucine cation were observed at 231 cm-1 and 258 cm-1 in the INS spectrum. Temperature-dependent far-infrared spectra in the temperature range 9 K-290 K were obtained. Vibrational bands were analyzed as a function of temperature. Activation energies for reorientational motion of CH3 and CH2 groups were determined by means of the band shape analysis performed for torsional and twisting vibrations of these groups. The estimated energy is equal to Ea = 2.7 ±â€¯0.2 kJ/mol and Ea = 2.17 ±â€¯0.12 kJ/mol for CH3 and CH2 groups, respectively. A phase transition at about 130 K in the l-leucine - chloranilic acid complex was observed.

[3-Tesla MRI of rare large cystic prostate carcinoma]. / 3-Tesla-MRT von seltenen zystisch imponierenden Prostatakarzinomen.

Magnetic resonance imaging of rare cystic prostate cancers using multiparametric MRI (mp-MRI, 3 Tesla) shows, especially in solid tumor masses, the criteria of ESUR-MR classification with a PI-RADS >3 ("probably malignant"). In association with additional morphological evidence of intracystic hemorrhage and evidence of villous tumor nodules and irregular septa on the cyst wall, further malignancy criteria are met. MRI complementary to TRUS may be useful for targeted biopsy in solid tumor areas.

Deuterium isotope effects on 13C chemical shifts of negatively charged NH N systems.

Deuterium isotope effects on (13)C chemical shifts are investigated in anions of 1,8-bis(4-toluenesulphonamido)naphthalenes together with N,N-(naphthalene-1,8-diyl)bis(2,2,2-trifluoracetamide) all with bis(1,8-dimethylamino)napthaleneH(+) as counter ion. These compounds represent both "static" and equilibrium cases. NMR assignments of the former have been revised. The NH proton is deuteriated. The isotope effects on (13)C chemical shifts are rather unusual in these strongly hydrogen bonded systems between a NH and a negatively charged nitrogen atom. The formal four-bond effects are found to be negative indicating transmission via the hydrogen bond. In addition, unusual long range effects are seen. Structures, (1)H and (13)C NMR chemical shifts and changes in nuclear shieldings upon deuteriation are calculated using density functional theory methods.

4,4'-, 5,5'-, and 6,6'-dimethyl-2,2'-bipyridyls: the structures, phase transitions, vibrations, and methyl group tunneling of their complexes with chloranilic acid.

The crystal and molecular structures of 4,4(')- and 6,6(')-dimethyl-2,2(')-bipyridyl complexes with 2,5-dichloro-3,6-dihydroxy-p-benzoquinone (chloranilic acid, CLA) have been determined and compared with those of the complex with the 5,5(')-derivative, which is known to possess interesting antiferroelectric properties. In the crystalline state, all three compounds form hydrogen bonded chains with N(+)-H···O(-) and O-H···N bridges on both sides of the bipyridyl constituent. The comparison of three derivatives indicates that the N(+)-H···O(-) hydrogen bonds are shortest for the 5,5(')-dimethyl complex. The 4,4(')- and 6,6(')-derivatives do not show any ferroelectric feature. The 6,6(')-one is, however, characterized by a continuous phase transition, revealed in the differential scanning calorimetry, dilatometric, and dielectric characteristics. The tunneling splitting measured by neutron backscattering in the energy range ±30 µeV for the neat dimethyl bipyridyls and their complexes with CLA indicates that the different splittings are primarily due to the crystal packing effect and that charge transfer between interacting compounds plays only a minor role.

Low frequency internal modes of 1,2,4,5-tetramethylbenzene, tetramethylpyrazine and tetramethyl-1,4-benzoquinone INS, Raman, infrared and theoretical DFT studies.

The results of inelastic neutron scattering (INS), Raman and infrared (IR) studies on 1,2,4,5-tetramethylbenzene (durene), tetramethylpyrazine (TMP) and tetramethyl-1,4-benzoquinone (TMBQ) in the solid state are reported. The observed frequencies are analyzed on the basis of DFT calculations. The low frequency region, below 400 cm(-1), related to the torsional and bending out-of-plane vibrations of the CH(3) groups, is of particular interest. The detailed analysis is possible due to the simulation of the INS spectra by using the auntie-CLIMAX program. It is shown that the observed low frequency INS bands are dramatically shifted, compared to the calculated ones, towards higher frequencies. Although one cannot exclude deficiencies of theoretical methods as applied to low frequency modes, it seems more probable the interpretation based on an existence of non-conventional CH(...)pi, CH(...)N, CH(...)O hydrogen bonds formed by the methyl groups in crystalline phases.

l-Cysteine: Neutron spectroscopy, Raman, IR and ab initio study.

Inelastic incoherent neutron scattering (IINS) spectra were obtained at 10K for normal and deuterated l-cysteine. Raman and infrared spectra were also recorded. Geometry of l-cysteine molecule was optimized for the zwitterion form using ab initio HF/6-31G* level. The theoretical frequencies of normal and d(4)-l-cysteine were compared with INS, Raman and IR spectra. Normal coordinate analysis and band assignments based on ab initio calculations and experimental data are presented.

Inelastic neutron scattering (INS) studies on 2,5-dihydroxy-1,4-benzoquinone (DHBQ).

Inelastic neutron scattering (INS) spectra of solid 2,5-dihydroxy-1,4-benzoquinone were measured and compared with IR and Raman data. The INS spectrum is very well reproduced in the region below 1000 cm(-1) by DFT calculations on the B3LYP/6-311++G** level using Gaussian and Climax programs. To get a better agreement one should take into account additional interactions of OH groups in the solid state leading to an increase of the gamma(OH) frequency and to a decrease of frequencies for modes in which the delta(OH) participates. The studies of the deuterated compound in IR enabled to correct the assignment of gamma(OH) vibrations. Highly asymmetric nu(OH) band observed in IR spectrum with sharp maximum at about 3300 cm(-1) is discussed in terms of a stochastic approach to the analysis of hydrogen bonded systems.

Affiliation, community size, and person-positivity effect in return of lost letters.

A study using 1,008 "lost letters" was designed to test the hypotheses that returned responses would be greater in smaller rural communities than from cities, that addresses' affiliation with a group opposed to physical education in schools would reduce the return rate, and that a person-positivity effect would influence return rates. Community Size and Person-Positivity conditions were not significantly associated with different rates of return even though returned letters from the smaller rural communities were more frequent than those from the cities across addressee conditions. Findings seem to suggest no community bias in the willingness of people to help a stranger in need by returning a lost letter. Person-Positivity conditions did not seem to improve the technique. Both addressee' affiliations alone and community size and addressee' affiliations were associated with significantly different rates of return in smaller rural communities, with rates of return greater in the smaller rural communities than in the cities (except for the addressee opposed to physical education in schools).

[The performance evaluation of patients with osteoporosis]. / Zur Leistungsbegutachtung von Patienten mit Osteoporose.

Osteoporosis causes fractures of bones and thus disabilities. Patients with osteoporosis experience limitations in daily life and profession life. Rating of the disease is a prerequisite of judging the capability to work and keep on professional life. Osteoporosis is defined by a reduction of bone mineral density which is more than -2.5 standard deviations below mean peak bone mass. Severe or advanced osteoporosis is characterized by the occurrence of first atraumatic fractures. Expert advice has to consider that certain professions may cause deterioration of the disease and the disease itself may be incompatible with professional life.

Abortion affiliation, urban size, and geographic bias of responses to lost letters.

A study using 1800 "lost letters" was designed to test the hypothesis that returned responses would be greater in smaller rural communities (population M = 964) than in a city (population = 60,591) or the suburbs (population = 195,847) unless the addressee was affiliated with a pro-abortion group. Returns to control, Committee For Free Abortion, and Committee Against Free Abortion affiliates were 37.2%, 24.0%, 29.3%, respectively. From the city, the number of returned letters was much larger than the number from the suburbs except for those letters with an affiliation to the pro-abortion condition. Returned letters from the city were fewer than those from smaller rural communities except those letters affiliated with the pro-abortion group. More letters affiliated with the pro-abortion condition were returned from the suburbs than from the smaller rural communities. The geographic condition influenced over-all rates of return. Rates were higher when letters were addressed to a city P.O. Box than to a rural one. Second, rates were also greater in smaller rural communities for letters bearing "in-town" (Molino) and "out-of-town" (Pensacola) addresses than those from the city bearing an "out-of-town" (Molino) address. These findings seem to indicate the possibility that there may be some geographic bias in the willingness of people to help a stranger in need by returning a lost letter.

PIP: This study was set up to test the hypothesis that returned responses would be greater in smaller rural communities than in city or the suburbs unless the addressee was affiliated with a pro-abortion group using the lost letter technique. Furthermore, this study seeks to examine whether urban size and geographic conditions in the area affected by violence influenced the return of lost letters. Different rates of results were reported. Returned letters from the city were fewer than those compared in the smaller rural communities except those letters with an affiliation to the committee for free abortion. More letters affiliated with the committee were returned from the suburbs than from the smaller rural communities. Geographic conditions significantly influence the overall returned responses. Rates were higher when letters were addressed to an urban P.O. Box than to a rural one. In addition, there was a greater rate in smaller rural communities for letters bearing "in-town" (Molino) and "out-of-town" (Pensacola) addresses than those from the city bearing an "out-of-town" (Molino) address. Lastly, with these findings, it was clear that there was a possibility that there may be some geographic bias in the willingness of the people to help a stranger in need by returning a lost letter.

Endogenous nitrate synthesis in selected infectious diseases and ulcerative colitis.

Investigations into acute and chronic diarrheal patients confirmed the results of animal experiments on the role of cytotoxic activated macrophages in endogenous formation of nitrates. Because a number of inflammatory diseases did not cause a nitrate release in urine, blood, and saliva, the general importance of nitrates to characterize the initiation and course of inflammations must be questioned.

[Results of clinical and epidemiologic studies of the nitrate problem]. / Ergebnisse klinischer und epidemiologischer Untersuchungen zum Nitratproblem.

Small differences in nitrate intake with the drinking water are not reflected in nitrate contents of saliva and urine of test persons. A correlation of nitrate concentration in body fluids and cancer incidence can be expected hardly. Inflammatory diseases of the gut are frequently accompanied by enhanced endogenous nitrate synthesis and have an essential influence on total nitrate load of the human organism. Nitrate contents in saliva and/or urine are not general indicators of inflammatory processes. As the role of the nitrate ion in humans is not yet understood, the claim remains for a nitrate intake being as low as possible.

Thyroid hormone metabolism under extreme body exercises.

In two runs over a distance of 75 km and 45 km as well as in a marathon (42.2 km), the thyroid hormones (T4, T3 and TSH in all runs and rT3 in two of them) were determined before and after the runs. The performance of the runners was analyzed, with their age considered in the analysis. We found that the changes of thyroid hormones are characterized by individual differences. Younger runners and those with better performances had significantly higher T4 serum concentrations and unaltered T3 and TSH concentrations, whereas older sportsmen and those with worse performances reacted to the stressful stimulus with a significant decrease of T4, T3 and TSH. This response was interpreted as an exhaustion reaction, i.e. reduced adaptation responses of thyroid hormone metabolism. Therefore, these investigations provide an assessment of the state of fitness, the optimization of training and the avoidance of damage caused by overly stressful physical exercise

Effect of endurance exercise on somatomedin-C/insulin-like growth factor I concentration in male and female runners.

By means of 3 endurance exercises, the effect of a several-hour intensive somatic stress on the changes of the Sm-C/IGF-I concentration was tested during, immediately after and on the day following the exercise. Exp. 1: Marathon with 17 male sportsmen in 2 groups with different glucose supply. Exp. 2: 45-km crosscountry run with 41 males. Exp. 3: Three 20-km runs with 8 young females at intervals of 3 months. In the marathon, no significant changes of the Sm-C/IGF-I concentration were found between the start, half distance and final values. The exogenous glucose supply (continuous or discontinuous) had also no effect. The tendency of a slight decrease of the Sm-C/IGF-I concentration by 0.14 U/ml (p greater than 0.05) was observed between start and finish in the 45 km crosscountry run lasting one hour longer. In the three 20-km runs, reproducible, slightly increased levels were measured at the end, whereas a decrease to the initial value or even below was detected on the following day (p greater than 0.05). The insignificant alterations of the Sm-C/IGF-I concentration measured in the 3 variants of races show that neither the hormonal changes stimulating the Sm-C/IGF-I synthesis (e.g. increase of GH and prolactin) nor inhibiting factors (energy deficiency) clearly dominate during strenuous exercises. The binding of carrier protein prevents great variations of the Sm-C/IGF-I level even under the condition of 3- to 4-hour extreme endurance exercises.