Conformation-Controlled Diplatinum(II)-Ferrocene Dyads to Achieve Long-Lived Charge-Separated States.

Square-planar polypyridyl platinum(II) complexes possess a rich range of structural and spectroscopic properties that are ideal for designing artificial photosynthetic centers. Taking advantage of the directionality in the charge-transfer excitation from the metal to the polypyridyl ligand, we describe here diplatinum(II)-ferrocene dyads, open-butterfly-like dyad 1 and closed-butterfly-like dyad 2, which were designed to understand the conformation and orientation effects to prolong the lifetime of charge-separated state. In contrast to the open-butterfly-like dyad 1, the closed-butterfly-like dyad 2 shows three-times long lifetime of charge separated state upon photoexcitation, demonstrating that the orientation in the rigid structure of dyad 2 is a very important issue to achieve long-lived charge separated state.

[Author and time of writing of Shanghanlun Jujie].

Li Wenjin (courtesy name of Xiangyi, the styled names as Zhian and Shujingtang Zhuren), lived in Xu Village, south of Tianyin Mountain, Jinling. He was born on the 47(th) year of the Kangxi Period (1708) and died approximately at the end of the Qianlong Period. Bold and generous, he liked making friends and practising medicine, divination, astrology, and also writing poetry and painting. Later he devoted himself to medicine and wrote Shanghanlun Jujie and Yijia 24 ze. Shanghanlun Jujie included Shanghanzabinglun Shujingtangqinjie (14 volumes) and Siwenji (7 volumes). The former one was written in 1768 and was his annotation of Shanghanlun. Siwenji included Shujingtang Gaidingzhushi Hanrewenpingyaoxingfu (4 volumes), Shujingtang Shenyizazhu (1 volume), Yiyao Zhenyan (1 volume) and Shujingtang Yiyaojian (1 volume) and was finished in 1765.

Thermostability of fluconazole with different crystal forms / 中国药学杂志

OBJECTIVE: To investigate the thermostability of four crystal forms of fluconazole. METHODS: The thermostability of fluconazole was analyzed using XRD, DSC and TGA, and the structural characteristics of the crystal forms and crystalline transformation were determined using XRD with in-situ high temperature accessories. RESULTS: The crystal form I and II had good at thermostability, and the crystal structure of form III changed at about 40°C. The monohydrate transformed to form II at about 70°. CONCLUSION: The different crystal forms of fluconazole have distinct thermostability. The result of this study would provide a comprehensive reference for the quality evaluation of fluconazole.

Determination of related substances in fluconazole bulk drug / 中国药学杂志

OBJECTIVE: To establish an HPLC gradient elution method for the determination of related substances in fluconazole bulk drug. METHODS: The separation was achieved by using an ODS column with gradient elution of mobile phase composed of 0.01 mol · L-1 ammonium formate and acetonitrile. The flow rate was 0.5 mL · min-1. The UV detection wavelength was 261 nm, injection volume is 20 μL. RESULTS: Fluconazole and its related substances can be separated effectively by this method, linear relation of fluconazole and impurity B-D were good, the detection limit were 0.20, 0.0052, 0.0073, 0.13 μg · mL-1, seventeen batches sample from nine manufacturers were determined. The related substances in fluconazole bulk drug were effectively determined. CONCLUSION: The HPLC method is rapid and accurate which may be used for the inspection of related substances in fluconazole bulk drug. Copyright 2012 by the Chinese Pharmaceutical Association.

Color-tuning mechanism of firefly investigated by multi-configurational perturbation method.

This is the first report on a multiconfigurational reference second-order perturbation theory-molecular mechanics study of the color modulation of the observed bioluminescence of the oxyluciferin-luciferase complex of the Japanese genji-botaru firefly using structures according to recent X-ray data. Our theoretical results do not support the experimentally deduced conclusion that the color modulation of the emitted light primarily depends on the size of the compact luciferase protein cavity embedding the excited oxyluciferin molecule. Rather, we find, in agreement with recent experimental observations, that the wavelength of the emitted light depends on the polarity of the microenvironment at the phenol/phenolate terminal of the benzothiazole fragment in oxyluciferin.

[The study of ultra-fine diamond powder used in magnetic head polishing slurry].

In the present paper, atomic absorption spectrometry(AAS), inductively-coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and laser Raman spectroscopy (RM) were employed to study the commercial ultra-fine diamond powders prepared by the static pressure-catalyst method and used in magnetic head polishing slurry. The results of AAS and ICP-MS indicated that there were silicon oxide, Fe, Ni, Al and some other metal elements in the ultra-fine powders. XRD patterns showed the peaks of SiO2 at 2theta = 35.6 degrees, 39.4 degrees and 59.7 degrees and diamond sharp peaks in agreement with the results above. Diamond sharp peaks implied perfect crystal and high-hardness beneficial to high-efficiency in polishing. The broader Raman band of graphite at 1 592 cm(-1) observed by Raman analysis proved graphite existing in the diamond powders. In the TEM images, the size of ultra-fine powders was estimated between 0.1 and 0.5 microm distributed in a wide scope, however, sharp edges of the powder particles was useful to polish. The ultra-fine diamond powders have many advantages, for example, high-hardness, well abrasion performance, high-polishing efficiency and being useful in magnetic head polishing slurry. But, the impurities influence the polishing efficiency, shortening its service life and the wide distribution reduces the polishing precision. Consequently, before use the powders must be purified and classified. The purity demands is 99.9% and trace silicon oxide under 0.01% should be reached. The classification demands that the particle distribution should be in a narrower scope, with the mean size of 100 nm and the percentage of particles lager than 200 nm not over 2%.

H(2)S protects myocardium against ischemia/reperfusion injury and its effect on c-Fos protein expression in rats / 生理学报

<p><b>UNLABELLED</b>The present study was aimed to study the effect of hydrogen sulfide (H(2)S) on rat myocardial ischemia/reperfusion (I/R) injury and whether the effect is mediated by c-Fos protein expression. Male Sprague-Dawley rats were randomly divided into 4 groups:</p><p><b>CONTROL GROUP</b>sham treatment; I/R group: the rat anterior descending branch of left coronary artery was occluded for 30 min and then released to allow reperfusion for 60 min; NaHS (exogenous H(2)S donor) groups: the rats were pretreated with NaHS at 2.8 μmol/kg body weight and 14 μmol/kg body weight (i.v.), respectively, before I/R treatment. Hemodynamics (LVSP, LV±dp/dt(max)) and electrocardiogram (ECG, lead II) were monitored continuously with multi-channel physiological signal analysis system after reperfusion. Myocardial infarct size was measured using triphenyltetrazolium chloride (TTC) staining. H(2)S concentration in the plasma was determined with a spectrophotometer. Morphological and ultrastructural changes in myocardial tissue were evaluated by HE staining and by a transmission electron microscope. The evaluation of c-Fos protein expression in myocardial tissue was performed by immunohistological staining. The results showed that H(2)S concentration in rat plasma in I/R group was significantly decreased compared with that in the control group [(30.32±5.26) vs (58.28±7.86) μmol/L, P<0.05]. NaHS at 2.8 and 14 μmol/kg body weight reduced the changes in LVSP, LV±dp/dt(max) in rat myocardium induced by I/R injury. The values of LVSP, +dp/dt(max) and -dp/dt(max) at 60 min during myocardial reperfusion were enhanced from (75.93±1.10)%, (66.27±4.78)% and (66.01±4.79)% in I/R group to (84.34±2.24)%, (76.38±1.93)% and (75.47±5.29)% in 2.8 μmol/kg body weight NaHS group (P<0.05, P<0.01, n=6), (88.40±2.88)%, (80.10±2.09)% and (80.48±6.20)% in 14 μmol/kg body weight NaHS group (P<0.01, n=6), respectively. Compared with that in 2.8 μmol/kg body weight NaHS group, the enhancing effect was more prominent in 14 μmol/kg body weight NaHS group. NaHS at 14 μmol/kg body weight markedly alleviated the injury in morphological changes and decreased c-Fos protein expression in myocardial tissue compared with that in I/R group (0.20±0.06 vs 0.32±0.10, P<0.05). These results suggest that H(2)S protects myocardium against I/R injury and this protective effect may be related to the down-regulation of c-Fos protein expression.</p>

Structures and cis-to-trans photoisomerization of hexafluoro-1,3-butadiene radical cation: electron spin resonance and computational studies.

The s-cis and s-trans isomer radical cations of hexafluoro-1,3-butadiene (s-cis-HFBD+ and s-trans-HFBD+) were generated by a gamma-irradiated solid solution of the neutral HFBD molecule in solid matrix at 77 K and observed by means of electron spin resonance (ESR) and electronic spectroscopies. In comparing the experimental isotropic and anisotropic 19F hyperfine splittings with the computational ones by the DFT B3LYP and MP2 methods, the generated s-cis-HFBD+ and s-trans-HFBD+ radical cations were confirmed to be 2A2 and 2Bg electronic ground states in C2v and C2h symmetries, respectively. The present spectroscopic study revealed that the relative abundance of s-cis-HFBD+ to s-trans-HFBD+ was 4.0 immediately after being formed by gamma-irradiation, and subsequently most s-cis-HFBD+ was isomerized to s-trans-HFBD+ by visible-light illumination with 500-600 nm wavelength. The process of nonplanar HFBD ionizing to form stable planar s-cis- and s-trans-HFBD+ and the reaction mechanism of the cis-to-trans photoisomerization were discussed by (MS-)CASPT2//CASSCF calculated vertical excitation energies (Tv) and torsional potential energy curves (TPECs) of HFBD and HFBD+.

Multireference theoretical investigation on selectivity of the bond fissions in photodissociation of acetyl cyanide.

The selectivity of the C-CH(3) and C-CN bond fissions upon excitation of acetyl cyanide at 193 nm has been investigated at the theoretical level of multistate complete active space self-consistent field second order perturbation. The calculated results indicated that the initially excited S(3) state relaxes to S(2) via ultrafast internal conversion. The S(2) state could dissociate via two pathways. One, adiabatically dissociates to CH(3)CO(X)+CN(A). The other one internally converts to S(1) before S(1) intersystem crossing to T(1). The T(1) state subsequently dissociates to two groups of products: CH(3)(X)+OCCN(X) and CH(3)CO(X)+CN(X). The experimentally observed preference branching of CN elimination over CH(3) one and bond selectivity are the results of the competition between the adiabatic and nonadiabatic dynamics of the S(2) state.

Expressions of LRP, GST-pi and MRP1 in acute leukemia patients and its clinical significance / 中国实验血液学杂志

This study was purposed to investigate the relationship of expressions of gluthatione-S-transferase-pi (GST-pi), multidrug resistance protein-1 (MRP-1), lung resistance protein (LRP) with multidrug resistance of acute leukemia (AL), the correlation between 3 kinds protein expressions and the correlation of their protein expression with clinical features of AL patients. The S-P immunohistochemical staining method was used to determine the expressions of GST-pi, MRP1 and LRP proteins in 80 AL patients and 30 normal subjects. The results showed that there was the correlation between GST-pi, MRP1, LRP protein expression and chemotherapy resistance, meanwhile CR rates of patients with positive expression of those proteins were lower than that of patients with negative expression (P<0.05), so those protein expressions may be accounted for poor prognosis. There was the positive relationship between expression of GST-pi and MRP1 in refractory group (r=0.851, P<0.01). It is concluded that co-examination of GST-pi and MRP1 has greater significance than examination of one kind of protein in evaluating poor prognosis of leukemia patients. LRP protein expression increase obviously when WBC counts >or= 10 x 10(9)/L (63.6%, P<0.05), therefore LRP protein has great judging value for evaluating drug resistance and prognosis of acute leukemia patients whose peripheral blood WBC counts were high.

Salusins protect neonatal rat cardiomyocytes from serum deprivation-induced cell death through upregulation of GRP78.

Salusin-alpha and salusin-beta are newly identified bioactive peptides with hemodynamic and mitogenic activities. Recent studies have shown that salusins improve calcium uptake and protein synthesis in neonatal rat cardiomyocytes, suggesting that salusins may be regulatory factors for myocardial growth and hypertrophy. In this study, we investigated whether salusins improve the survival of cardiomyocytes after serum deprivation. Cultured neonatal cardiomyocytes were treated with or without salusins (salusin-alpha or salusin-beta) at a concentration range of 10 to 10 mol/L for 24 h under serum deprivation conditions. Cardiomyocytes viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazonium bromide assay. Cell death or apoptosis rate was identified by flow cytometry analysis. Compared to serum deprivation-only groups, cardiomyocyte viability was significantly increased in salusin-alpha or salusin-beta groups. Cell death rate was decreased after administration of 10 mol/L salusin-alpha or salusin-beta. Salusin-beta was able to decrease the apoptotic rate. Salusins also increased the expression of cardiomyocyte glucose-regulated protein 78 (GRP78) as estimated by Western blot. Furthermore, antisense oligodeoxynucleotide specifically against GRP78 attenuated or abrogated antiapoptosis or survival effects of salusin-beta. These findings suggest that salusin-alpha and salusin-beta may be a potential survival factor against serum deprivation-induced myocardial cell death and that this cardioprotective effect may involve an upregulation of GRP78 expression in cardiomyocytes.

Humane endpoints in shock research.

In biomedical research using animal models, the phrase "humane endpoints" refers to predetermined criteria used to judge when the research animals should be humanely euthanized. The intended goal of humane endpoints is to minimize the distress or suffering of research animals; however, if applied incorrectly, this well-intended concept could lead to premature decisions and inaccurate data, resulting in a waste of animal life. A concensus on specific endpoints for shock and inflammation research is not available but several biochemical, physical and behavioral parameters have been suggested for other research models. In addition, the authors have found, in the studies presented here, that increasing body weight, decreased body temperature, and inability to ambulate are important parameters in a model of cecal ligation and puncture. However, it is clear that the applicability of these endpoints may change with the model of disease, intensity of insults, experimental treatments and other factors. Consequently, humane endpoints should be assigned cautiously and preferably after preliminary studies to prevent aberrant research results. In order to accomplish this, investigators must become aware of certain concepts including: when to implement endpoints, what endpoints to consider, and how to establish the endpoints for their studies. Equipped with the basic principles of humane endpoints, investigators can make informed decisions that meet current standards of animal care while still achieving the scientific goals of their research studies.