Filling the gaps in icosahedral superatomic metal clusters.

Chemically modified superatoms have emerged as promising candidates in the new periodic table, in which Au13 and its doped M n Au13- n have been widely studied. However, their important counterpart, Ag13 artificial element, has not yet been synthesized. In this work, we report the synthesis of Ag13 nanoclusters using strong chelating ability and rigid ligands, that fills the gaps in the icosahedral superatomic metal clusters. After further doping Ag13 template with different degrees of Au atoms, we gained insight into the evolution of their optical properties. Theoretical calculations show that the kernel metal doping can modulate the transition of the excited-state electronic structure, and the electron transfer process changes from local excitation (LE) to charge transfer (CT) to LE. This study not only enriches the families of artificial superatoms, but also contributes to the understanding of the electronic states of superatomic clusters.

Atomically Precise Chiral Metal Nanoclusters for Circularly Polarized Light Detection.

Circularly polarized light (CPL) detection is of great significance in various applications such as drug identification, sensing and imaging. Atomically precise chiral metal nanoclusters with intense circular dichroism (CD) signals are promising candidates for CPL detection, which can further facilitate device miniaturization and integration. Herein, we report the preparation of a pair of optically active chiral silver nanoclusters [Ag7(R/S-DMA)2(dpppy)3] (BF4)3 (R/S-Ag7) for direct CPL detection. The crystal structure and molecular formula of R/S-Ag7 clusters are confirmed by single-crystal X-ray diffraction and high-resolution mass spectrometry. R/S-Ag7 clusters exhibit strong CD spectra and CPL both in solution and solid states. When used as the photoactive materials in photodetectors, R/S-Ag7 enables effective discrimination between left-handed circularly polarized and right-handed circularly polarized light at 520 nm with short response time, high responsivity and considerable discrimination ratio. This study is the first report on using atomically precise chiral metal nanoclusters for CPL detection.

Orexin-A aggravates cognitive deficits in 3xTg-AD mice by exacerbating synaptic plasticity impairment and affecting amyloid ß metabolism.

Dementia is the main clinical feature of Alzheimer's disease (AD). Orexin has recently been linked to AD pathogenesis, and exogenous orexin-A (OXA) aggravates spatial memory impairment in APP/PS1 mice. However, the effects of OXA on other types of cognitive deficits, especially in 3xTg-AD mice exhibiting both plaque and tangle pathologies, have not been reported. Furthermore, the potential electrophysiological mechanism by which OXA affects cognitive deficits and the molecular mechanism by which OXA increases amyloid ß (Aß) levels are unknown. In the present study, the effects of OXA on cognitive functions, synaptic plasticity, Aß levels, tau hyperphosphorylation, BACE1 and NEP expression, and circadian locomotor rhythm were evaluated. The results showed that OXA aggravated memory impairments and circadian rhythm disturbance, exacerbated hippocampal LTP depression, and increased Aß and tau pathologies in 3xTg-AD mice by affecting BACE1 and NEP expression. These results indicated that OXA aggravates cognitive deficits and hippocampal synaptic plasticity impairment in 3xTg-AD mice by increasing Aß production and decreasing Aß clearance through disruption of the circadian rhythm and sleep-wake cycle.

[The Roles of RUNX1 in the Proliferation and Osteogenic and Adipogenic Differentiation of Dental Pulp Stem Cells].

OBJECTIVE: To investigate the influence of Runt-related transcription factor 1 (RUNX1) on the proliferation, osteogenic differentiation and adipogenic differentiation of dental pulp stem cells (DPSC) in vitro. METHODS: DPSCs were transfected through lentiviral vector carrying the target gene RUNX1 and green fluorescent protein (GFP). After 48 h, transfection efficiency was determined with the fluorescent marking of GFP and Western blot. The effect of the overexpression of RUNX1 on DPSC proliferation and colony formation was determined with CCK-8 and colony formation assay; cell cycle of DPSC was detected by flow cytometry. RUNX1 siRNA was transfected into the DPSCs. After mineralized induction, the effect of RUNX1 overexpression/silencing on the osteogenetic differentiation of DPSC was tested by alkaline phosphatase (ALP) staining and alizarin red staining. After adipogenic induction, oil red O staining was done in order to observe the effect of overexpression/silencing of RUNX1 on the adipogenic differentiation of DPSC. RESULTS: RUNX1 protein was overexpressed in DPSC after lentiviral transfection. Fluorescent test showed successful transfection of lentiviral transfection and over 70% of the cells showed stable expression of GFP protein. The proliferation and colony-formation efficiency of DPSC was enhanced significantly and the proportion of DPSCs in the S phase was significantly increased in the RUNX1-overexpessed group ( P<0.05). ALP activity and mineralized nodule formation ability increased, while lipid droplets decreased in the RUNX1-overexpessed group ( P<0.05). ALP activity and mineralized nodule formation ability decreased, while lipid droplets increased in the RUNX1 knockdown group ( P<0.05) . CONCLUSION: RUNX1 promotes DPSC proliferation and osteogenic differentiation while it inhibits DPSC adipogenic differentiation.

[Synergistic Antibacterial Activity of Berberine in Combination with Amylmetacresol Against Enterococcus faecalis in vitro].

OBJECTIVE: To study the antibacterial effect of berberine combined with amylmetacresol on Enterococcus faecalis. METHODS: Both dilution method and live bacteria CFU were used to determine the minimum inhibitory concentration (MIC) of berberine and amylmetacresol on E. faecalis. The killing effect of berberine and amylmetacresol on planktonic E. faecalis was detected by suspension quantitative germicidal test and live/dead bacteria staining. The effects of berberine and amylmetacresol on the structure of mature biofilm of E. faecalis was observed by scanning electron microscopy (SEM). The toxicity of berberine and amylmetacresol on human oral keratinocytes (HOK) was determined by CCK-8 cell proliferation and cytotoxicity assay and cytotoxicity LDH assay. RESULTS: The MIC of berberine was 512 µg/mL, and the MIC of amylmetacresol was 0.023 3%. 512 µg/mL berberine and 0.002 33% amylmetacresol had a weak killing effect on planktonic E. faecalis alone, while they showed a synergistic antibacterial effect in combination. Cell survival in the biofilm was only slightly changed by berberine and amylmetacresol. The structure of biofilm was obviously changed by berberine and amylmetacresol. 512 µg/mL berberine and 0.002 33% amylmetacresol alone or in combination showed the survival rate was much higher than the injury rate, suggesting berberine and amylmetacresol had a low cytotoxicity. CONCLUSION: Berberine and amylmetacresol had synergism against E. faecalis, and the biological safety of the combination use was better.

Abdominal imaging in AIDS patients / 中华放射学杂志

Objective To evaluate abdominal imaging in AIDS.Methods The imaging examinations(including US,CT and MR)of 6 patients with AIDS associated abdominal foci were analysed retrospectively.All the cases were performed US,and CT scan,of which 4 performed enhanced CT scan and 1 with MR.Results Abdominal tuberculosis were found in 4 patients,including abdominal lymph nodes tuberculosis(3 cases)and pancreatic tuberculosis(1 case).The imaging of lymph nodes tuberculosis typically showed enlarged peripheral rim enhancement with central low-attenuation on contrast-enhanced CT. Pancreatic tuberculosis demonstrated low-attenuation area in pancreatic head and slightly peripheral enhancement.Disseminated Kaposi's sarcoma was seen in 1 case:CT and MRI scan demonstrated tumour infiltrated along hepatic portal vein and bronchovascular bundles.Pelvic tumor was observed in 1 case:CT scan showed large mass with thick and irregular wall and central low attenuation liquefacient necrotic area in the pelvic cavity.Conclusion The imaging findings of AIDS with abdominal foci is extraordinarily helpful to the diagnosis of such disease.Tissue biopsy is needed to confirm the diagnosis.

Imaging findings of soft tissue infections in AIDS(report of 3 cases) / 中华放射学杂志

Objective To evaluate X-ray,CT and MRI findings of soft tissue infections in AIDS. Methods Three cases of soft tissue infections with AIDS were retrospectively analyzed by comparing the imaging findings with pathological results.All patients were performed MRI,X-ray was in 1 case,CT was in 1 case.Results Cellulitis was in 1 case:MRI showed extended thickening of subcutaneous tissues, ill-defined hypointense areas on T_1WI and hyperintensity on T_2WI,and reticular pattern on GRE. Necrotizing fasciitis was in 1 case:MRI showed obvious thickening of subcutaneous tissues and deep fasciae, abnormally increased signal intensity on T_1 and T_2WI.Fluid collections were within muscles and muscles interval on fat-suppressed T2 WI.Tuberculosis was in 1 case:CT demonstrated multiple low density areas in the subcutaneous tissues and clear peripheral rim enhancement.MRI appeared hypointense on T_1WI and hyperintensity on T_2WI,and peripheral rim enhancement following gadolinium injection.Conclusion Infections of soft tissue are common complication in patients with AIDS,radiology is important in early diagnosis and treatment planning in this population.