[Efficacy and safety of low dose sublingual nifedipine dripping pills (5 mg) in the acute treatment of moderate and severe hypertension: a randomized, double-blind, positive-drug parallel-controlled, multi-center clinical study].

Objective: To evaluate the efficacy and safety of low dose sublingual nifedipine dripping pills (5 mg) in treating moderate and severe hypertension in comparison with normal dose (10 mg) of sublingual nifedipine dripping pills. Methods: This study was designed as a randomized, double-blind, positive drug parallel controlled, multi-center, non-inferiority clinical trial. Patients with moderate and severe hypertension were enrolled by 14 clinical trial centers, randomly divided into the trial group (sublingual 5 mg nifedipine dripping pills) and the control group (sublingual 10 mg nifedipine dripping pills). The changes in blood pressure were monitored continuously within 2 hours after the initial administration, repeated the dose in 20 minutes interval after the initial administration for up to additional 3 doses (maximum 4 doses) if the antihypertensive efficacy was not satisfactory. The efficacy of antihypertensive therapy between the two groups was evaluated by repeated administration rates and blood pressure changes at 60 minutes post the initial administration, and the safety of treatment was evaluated by recording adverse event rate of the two groups. Results: The anti-hypertensive effective rates at 60 minutes after sublingual administration were 83.5% (202/242) and 86.7% (208/240) respectively between the trial group and control group (χ(2)=1.307, P=0.253) . On the aspect of antihypertensive effectiveness at 60 minutes after single dose of sublingual administration, the anti-hypertension effective rates of the trial group and the control group were 85.6% (154/180) and 87.2% (164/188) respectively (χ(2)=0.221, P=0.639). Prevalence of the repeated administration was also similar between the two groups (25.6%(62/242) in the trial group and 21.7% (52/240) in the control group, χ(2)=1.043, P=0.307). On the safety aspect, there was no adverse events/reactions in the trial group, but there were 15 cases of adverse events/reactions occurred in control group (6.25%, χ(2)=15.611, P<0.001). Conclusions: In the treatment of moderate to severe hypertension, the antihypertensive efficacy of low dose nifedipine dripping pills is similar to that of conventional dosage, and the safety profile of low dose nifedipine dripping pills is better than that of the conventional dose.

Very small photoluminescent gold nanoparticles for multimodality biomedical imaging.

An original synthesis method based on X-ray irradiation produced gold nanoparticles (AuNPs) with two important properties for biomedical research: intense visible photoluminescence and very high accumulation in cancer cells. The nanoparticles, coated with MUA (11-mercaptoundecanoid acid), are very small (1.4 nm diameter); the above two properties are not present for even slightly larger sizes. The small MUA-AuNPs are non-cytotoxic (except for very high concentrations) and do not interfere with cancer cell proliferation. Multimodality imaging using visible light fluorescence and X-ray microscopy is demonstrated by tracing the nanoparticle-loaded tumor cells.

Imaging cells and sub-cellular structures with ultrahigh resolution full-field X-ray microscopy.

Our experimental results demonstrate that full-field hard-X-ray microscopy is finally able to investigate the internal structure of cells in tissues. This result was made possible by three main factors: the use of a coherent (synchrotron) source of X-rays, the exploitation of contrast mechanisms based on the real part of the refractive index and the magnification provided by high-resolution Fresnel zone-plate objectives. We specifically obtained high-quality microradiographs of human and mouse cells with 29 nm Rayleigh spatial resolution and verified that tomographic reconstruction could be implemented with a final resolution level suitable for subcellular features. We also demonstrated that a phase retrieval method based on a wave propagation algorithm could yield good subcellular images starting from a series of defocused microradiographs. The concluding discussion compares cellular and subcellular hard-X-ray microradiology with other techniques and evaluates its potential impact on biomedical research.

Low-energy charge-density excitations in MgB2: Striking interplay between single-particle and collective behavior for large momenta.

A sharp feature in the charge-density excitation spectra of single-crystal MgB2, displaying a remarkable cosinelike, periodic energy dispersion with momentum transfer (q) along the c* axis, has been observed for the first time by high-resolution nonresonant inelastic x-ray scattering (NIXS). Time-dependent density-functional theory calculations show that the physics underlying the NIXS data is strong coupling between single-particle and collective degrees of freedom, mediated by large crystal local-field effects. As a result, the small-q collective mode residing in the single-particle excitation gap of the B pi bands reappears periodically in higher Brillouin zones. The NIXS data thus embody a novel signature of the layered electronic structure of MgB2.

Orbitally driven spin-singlet dimerization in S=1 La4Ru2O10.

Using x-ray absorption spectroscopy at the Ru-L2,3 edge we reveal that the Ru4+ ions remain in the S=1 spin state across the rare 4d-orbital ordering transition and spin-gap formation. We find using local spin density approximation + Hubbard U band structure calculations that the crystal fields in the low-temperature phase are not strong enough to stabilize the S=0 state. Instead, we identify a distinct orbital ordering with a significant anisotropy of the antiferromagnetic exchange couplings. We conclude that La4Ru2O10 appears to be a novel material in which the orbital physics drives the formation of spin-singlet dimers in a quasi-two-dimensional S=1 system.

Hyperhomocysteinemia is associated with volumetric white matter change in patients with small vessel disease.

BACKGROUND: Hyperhomocysteinemia is associated with cerebral small vessel disease (SVD). We examined the relationship between homocysteine and 1) volumetric measure of white matter change (WMC), 2) silent brain infarcts, 3) cerebral atrophy on MRI and 4) cognition on a consecutive cohort of patients with stroke associated with SVD. SUBJECTS AND METHODS: Fifty-seven patients consecutively admitted to the Acute Stroke Unit in a university hospital due to stroke associated with SVD were recruited and assessed three months after the stroke. Non-fasting homocysteine was obtained. Using MRI, the number of infarcts, volume of WMC and cerebral atrophy were measured. General cognitive functions were assessed using the Mini Mental State Examination and Alzheimer's disease Assessment Scale. Mattis Dementia Rating Scale - Initiation/Perseveration subset was used to assess executive cognitive functions. RESULTS: Hyperhomocysteinemia (> or = 14.88 micromol/L) significantly accounted for the volume of WMC on MRI in a multivariate stepwise regression model (adjusted R(2)=0.058, p <0.05) after adjustment for age and folate level. Patients in the highest quartile of WMC volume had significantly higher levels of homocysteine than those in lowest quartile (p <0.001). No significant relationship was found between homocysteine and silent brain infarcts, cerebral atrophy and performance on psychometric tests. CONCLUSION: Hyperhomocysteinemia is associated with volumetric measure of WMC among patients with SVD. The role of homocysteine in the development of silent brain infarcts and cerebral atrophy as previously reported cannot be ascertained in this study. No direct relationship was found between homocysteine and cognitive functions.

The X-ray Surface Forces Apparatus: Structure of a Thin Smectic Liquid Crystal Film Under Confinement.

An x-ray surface forces apparatus for simultaneously measuring forces and structures of confined complex fluids under static and flow conditions is described. This apparatus, combined with an intense synchrotron x-ray source, allows investigation of molecular orientations within a thin liquid crystal film confined between two shearing mica surfaces 3900 angstroms apart. The layer-forming smectic liquid crystal 8CB (4-cyano-4'-octylbiphenyl) adopted a series of distinct planar layer orientations, including the bulk flow-forbidden b orientation.