Fast imaging of lenticulostriate arteries by high-resolution black-blood T1-weighted imaging with variable flip angles and acceleration by compressed sensitivity encoding.

OBJECTIVE: We investigated the feasibility of using compressed sensitivity encoding (CS-SENSE) to accelerate high-resolution black-blood T1-weighted imaging with variable flip angles (T1WI-VFA) for efficient visualization and characterization of lenticulostriate arteries (LSAs) on a 3.0 T MR scanner. MATERIALS AND METHODS: Twenty-five healthy volunteers and 18 patients with the cerebrovascular disease were prospectively enrolled. Healthy volunteers underwent T1WI-VFA sequences with different acceleration factors (AFs), including conventional sensitivity encoding (SENSE) AF = 3 and CS-SENSE AF = 3, 4, 5, and 6 (SENSE3, CS3, CS4, CS5, CS6, respectively) at 3 Tesla MRI scanner. Objective evaluation (contrast ratio and number, length, and branches of LSAs) and subjective evaluation (overall image quality and LSA visualization scores) were used to assess image quality and LSA visualization. Comparisons were performed among the 5 sequences to select the best AF. All patients underwent both T1WI-VFA with the optimal AF and digital subtraction angiography (DSA) examination, and the number of LSAs observed by T1WI-VFA was compared with that by DSA. RESULTS: Pair-wise comparisons among CS3, CS4, and SENSE3 revealed no significant differences in both objective measurements and subjective evaluation (all P > 0.05). In patients, there was no significant difference in LSA counts on the same side between T1WI-VFA with CS4 and DSA (3, 3-4 and 3, 3-3, P = 0.243). CONCLUSIONS: CS3 provided better LSA visualization but a longer scan duration compared to CS4. And, CS4 strikes a good balance between LSA visualization and acquisition time, which is recommended for routine clinical use.

Separation of pyrrolidine from tetrahydrofuran by using pillar[6]arene-based nonporous adaptive crystals.

Pyrrolidine, an important feedstock in the chemical industry, is commonly produced via vapor-phase catalytic ammoniation of tetrahydrofuran (THF). Obtaining pyrrolidine with high purity and low energy cost has extremely high economic and environmental values. Here we offer a rapid and energy-saving method for adsorptive separation of pyrrolidine and THF by using nonporous adaptive crystals of per-ethyl pillar[6]arene (EtP6). EtP6 crystals show a superior preference towards pyrrolidine in 50 : 50 (v/v) pyrrolidine/THF mixture vapor, resulting in rapid separation. The purity of pyrrolidine reaches 95% in 15 min of separation, and after 2 h, the purity is found to be 99.9%. Single-crystal structures demonstrate that the selectivity is based on the stability difference of host-guest structures after uptake of THF or pyrrolidine and non-covalent interactions in the crystals. Besides, EtP6 crystals can be recycled efficiently after the separation process owing to reversible transformations between the guest-free and guest-loaded EtP6.

Chromogranin A-derived peptide CGA47-66 protects against septic brain injury by reducing blood-brain barrier damage through the PI3K/AKT pathway.

CGA47-66 (Chromofungin, CHR), is a peptide derived from the N-terminus of chromogranin A (CgA), has been proven to inhibit the lipopolysaccharide (LPS)-induced brain injury. However, the underlying mechanism is still unknown. We found that CGA47-66 exerted a protective effect on cognitive impairment by inhibiting the destruction of the blood-brain barrier (BBB) in the LPS-induced sepsis mice model. In addition, the hCMEC/D3 cell line was used to establish an in vitro BBB model. Under LPS stimulation, CGA47-66 could significantly alleviate the hyperpermeability of the BBB, the destruction of tight junction proteins, and the rearrangement of F-actin. To investigate the underlying mechanism, we used LY294002, a PI3K inhibitor, which partially reduced the protective effect of CGA47-66 on the integrity of BBB. Indicating that the PI3K/AKT pathway plays a vital role in the brain-protective function of CGA47-66, which might be a potential therapeutic target for septic brain injury.

Pillararene-Induced Intramolecular Through-Space Charge Transfer and Single-Molecule White-Light Emission.

The fabrication of single-molecule white-light emission (SMWLE) materials has become a highly studied topic in recent years and through-space charge transfer (TSCT) is emerging as an important concept in this field. However, the preparation of ideal TSCT-based SMWLE materials is still a big challenge. Herein, we report a bifunctional pillar[5]arene (TPCN-P5-TPA) with a linear donor-spacer-acceptor structure and aggregation-induced emission (AIE) property. The bulky pillar[5]arene between the donor and acceptor induces a twisted conformation and a non-conjugated structure, resulting in intramolecular TSCT. In addition, the AIE feature and pillar[5]arene cavity endow TPCN-P5-TPA with responsiveness to viscosity and polar guests, by which the TSCT emission is triggered. The combination of blue locally-excited state emission and yellow TSCT emission of TPCN-P5-TPA generates SMWLE. Therefore, we provide a new and versatile strategy for the construction of TSCT-based SMWLE materials.

Chemoresponsive Supramolecular Polypseudorotaxanes with Infinite Switching Capability.

Chemoresponsive supramolecular systems with infinite switching capability are important for applications in recycled materials and intelligent devices. To attain this objective, here a chemoresponsive polypseudorotaxane is reported on the basis of a bis(p-phenylene)-34-crown-10 macrocycle (H) and a cyano-substituted viologen guest (G). H and G form a [2]pseudorotaxane (H⊃G) both in solution and in the solid state. Upon addition of AgSF6 , a polypseudorotaxane (denoted as [H⋅G⋅Ag]n ) forms as synergistically driven by host-guest complexation and metal-coordination interactions. [H⋅G⋅Ag]n depolymerizes into a [3]pseudorotaxane (denoted as H2 ⋅G⋅Ag2 ⋅acetone2 ) upon addition of H and AgSF6 , while it reforms with successive addition of G. The transformations between [H⋅G⋅Ag]n and H2 ⋅G⋅Ag2 ⋅acetone2 can be switched for infinite cycles, superior to the conventional chemoresponsive supramolecular polymeric systems with limited switching capability.

[Surgical treatment of thoracic tuberculosis with one stage posterior debridement and bone grafting fusion and internal fixation].

OBJECTIVE: To investigate the effect and indication of one stage posterior debridement and bone grafting fusion and internal fixation for thoracic tuberculosis. METHODS: From January 2005 to May 2011,12 patients with thoracic tuberculosis were treated with one stage posterior debridement and pedicle screw fixation combined with regular anti-tuberculosis treatment before and after operation. There were 7 males and 5 females,with an average age of 45 years and average course of 15 months. Information of operative time, blood loss, bony fusion, local kyphosis and neurologic functional were evaluated. RESULTS: All infective focus were thoroughly removed and bone graft obtained fusion. The mean of operative time and blood loss were 170 min (120-210 min) and 510 ml (200-1 000 ml),respectively. Cobb angle from (28.7 +/- 9.2) degrees preoperatively decreased to (8.2 +/- 3.5) degrees postoperatively(P<0.05). No kyphosis correction loss,tubercular recurrence or failure of internal fixation was found. According to Frankel grade to evaluate neurological function, all patients arrived to grade E. CONCLUSION: One stage posterior debridement and bone grafting fusion and internal fixation is an effective method in treating thoracic tuberculosis. It has advantages such as thorough debridement, short operative time, less blood loss, more kyphosis correction and higher bony fusion rate.