Sign inversions of circularly polarized luminescence for helical compounds by chemically fine-tuning operations.

Sign inversions of circularly polarized luminescence (CPL) for the hydro[5]helicene and [5]helicene derivatives were discovered and studied experimentally and theoretically. The inverted CPL signs from the hydro[5]helicene to [5]helicene derivatives were realized by one-step oxidation. The introduction of triphenylamine (TPA) subunits into the helical skeletons also led to the sign inversion of CPL only when there existed an enhanced intramolecular charge-transfer state with a small enough Egap.

Metal-free construction of contiguous quaternary stereocentres with a polycyclic framework.

A series of contiguous all-carbon quaternary stereocentres with an arene-annulated polycyclic framework were constructed efficiently by a metal-free and atom economic acid-catalyzed method. The reactions could be performed by acid-catalyzed cationic cyclization and rearrangement under mild conditions. Moreover, the resulting polycyclic products showed highly twisted architectures with two perpendicular planes.

Synthesis, Structures, and Photophysical Properties of Optically Stable 1,16-Diphenyl-3,14-diaryl-Substituted Tetrahydrobenzo[5]helicenediol Derivatives: Enantioselective Recognition toward Tryptophan Methyl Esters.

Starting from commercially available 7-methoxytetralone, 1,16-diphenyl-3,14-dibromotetrahydrobenzo[5]helicenediol (Br-H[5]HOL) was conveniently prepared, which underwent efficient resolution to give the optically stable enantiomeric diols in gram scale by HPLC with semipreparative chiral columns. The absolute configurations of the diols were determined by the circular dichroism (CD) spectra and X-ray crystal structure. By Suzuki-Miyaura cross-coupling reactions, a series of enantiopure π-extended 1,16-diphenyl-3,14-diaryltetrahydrobenzo[5]helicenediol derivatives (Ar-H[5]HOL) were further synthesized in high yields. The enantiomeric Ar-H[5]HOL exhibited almost identical absorption and emission spectra but showed mirror-image CD spectra and mirror-image circularly polarized luminescence properties. Moreover, it was also found that aryl substituents at the 3,14-positions could extend the chiral environment of the helical skeletons, which led to efficient enantioselective recognition of the enantiomers of tryptophan methyl esters.

Synthesis, Structures, Resolution, and Chiroptical Properties of 1,16-Diaryl-Substituted Benzo[5]helicene Derivatives.

An efficient route to the synthesis of benzo[5]helicene derivatives functionalized on the interior side of the helix was developed, and resulted in a series of 1,16-diaryl-substituted benzo[5]helicene derivatives starting from easily available 7-methoxytetralone. X-ray crystal structures showed that the benzo[5]helicene derivatives had highly helical, twisted structures, and could all create hierarchical packing architectures with alternating P and M layers in the solid state. Moreover, seven pairs of enantiomers based on 1,16-diaryl-substituted benzo[5]helicene derivatives were also obtained by efficient resolution through HPLC with semipreparative chiral columns. The enantiomers all showed clear mirror-image circular dichroism (CD) spectra and high specific optical rotations, and their absolute configurations were determined by X-ray crystallography. Interestingly, a helical nanotubular structure was formed by the self-assembly of one enantiomer through halogen bonding. Furthermore, the enantiomers were found to have high racemization barriers and thermostability, which might be caused by the introduction of aryl substituents at the C1(C16) position.

MicroRNA profiling of the intestine during hypothermic circulatory arrest in swine.

AIM: To perform a profiling analysis of changes in intestinal microRNA (miRNA) expression during hypothermic circulatory arrest (HCA). METHODS: A total of eight piglets were randomly divided into HCA and sham operation (SO) groups. Under general anesthesia, swine in the HCA group were subjected to hypothermic cardiopulmonary bypass at 24 °C followed by 80 min of circulatory arrest, and the reperfusion lasted for 180 min after cross-clamp removal. The counterparts in the SO group were only subjected to median sternotomy. Histopathological analysis was used to detect mucosal injury, and Pick-and-Mix custom miRNA real-time polymerase chain reaction (PCR) panels containing 306 unique primer sets were utilized to assay unpooled intestinal samples harvested from the two groups. RESULTS: The intestinal mucosa of the animals that were subjected to 24 °C HCA exhibited representative ischemic reperfusion injury of grade 2 or 3 according to the Chiu score. Such intestinal mucosal injuries, with the subepithelial space and epithelial layer lifting away from the lamina propria, were accompanied by shortened and irregular villi. On the contrary, the intestinal mucosa remained normal in the sham-operated animals. In total, twenty-five miRNAs were differentially expressed between the two groups (15 upregulated and 10 downregulated in the HCA group). Among these, eight miRNAs (miR-122, miR-221-5p, miR-31, miR-421-5p, miR-4333, miR-499-3p, miR-542 and let-7d-3p) were significantly dysregulated (four higher and four lower). The expression of miR-122 was significantly (5.37-fold) increased in the HCA group vs the SO group, indicating that it may play a key role in HCA-induced mucosal injury. CONCLUSION: Exposure to HCA caused intestinal miRNA dysregulation and barrier dysfunction in swine. These altered miRNAs might be related to the protection or destruction of the intestinal barrier.

Realization of reliable solid-state quantum memory for photonic polarization qubit.

Faithfully storing an unknown quantum light state is essential to advanced quantum communication and distributed quantum computation applications. The required quantum memory must have high fidelity to improve the performance of a quantum network. Here we report the reversible transfer of photonic polarization states into collective atomic excitation in a compact solid-state device. The quantum memory is based on an atomic frequency comb (AFC) in rare-earth ion-doped crystals. We obtain up to 0.999 process fidelity for the storage and retrieval process of single-photon-level coherent pulse. This reliable quantum memory is a crucial step toward quantum networks based on solid-state devices.

[The standardized practice of laparoscopic-assisted radical right hemicolectomy in order to achieve complete mesocolic excision].

OBJECTIVE: To explore the feasibility of laparoscopic-assisted radical right hemicolectomy with the outcome being a complete mesocolic excision (CME). METHODS: Between February 2010 and June 2011, we performed the standardized surgery of laparoscopic-assisted radical right hemicolectomy with an aim of CME on 14 patients. There were 10 males and 4 females, with an average age of 57 years (range 36 to 74 years). All the pathologic results in 14 cases were primary colonic adenocarcinoma. The TNM stages were distributed as follows: 2 in II A, 3 in II B, 3 in III A, 5 in III B and 1 in III C. RESULTS: Surgery was successfully performed for all patients without open conversion. The average operation time was (178 ± 37) minutes (range 127 to 221 minutes), average intraoperative blood loss was (67 ± 23) ml (range 30 to 110 ml), while the average number of lymph node harvest was 21 ± 7 (range 14 to 31), and the postoperative hospital stay was (10.0 ± 2.2) days (range 7 to 15 days). Minor complications occured in 2 patients. Major complications and post-operative mortality were not observed. All the patients were followed up for 3 to 19 months, no tumor recurrence or metastasis was identified. CONCLUSION: The standardized surgery of laparoscopic-assisted radical right hemicolectomy with the final outcome of CME is safe and feasible.

Expression of heat shock protein 27 in the esophageal tissue of rats with reflux esophagitis.

BACKGROUND: Little attention has been paid to the expression of heat shock protein 27 (HSP27) in patients with reflux esophagitis (RE), and few studies of the importance of HSP27 in esophagitis have been carried out in animal models. This study aimed to explore the expression of HSP27 in the esophageal tissue of rats with RE. METHODS: Eighty female Wistar rats were randomly divided into experimental groups A and B and control groups C and D (n = 20 in each group). To establish RE, rats in the two experimental groups received pylorus and forestomach ligations, while rats in the control group received gastrostomy and gastric perforation repair. The rats in groups A and C were sacrificed 7 days after surgery, and the rats in groups B and D were sacrificed 14 days after surgery. In groups A and B, 10 and 8 rats were diagnosed with RE by pathological examination, respectively (they were included in groups A' and B', respectively). The histopathological diagnosis of all the lower esophageal tissues in groups C and D was normal and 20 normal specimens were randomly selected for groups C' and D' with 10 specimens in each group. Macroscopic and microscopic esophagitis scores were assessed for the specimens in groups A' and B'. Lower esophageal tissues were collected from groups A', B', C', and D', and paraffin-embedded slices were made using part of the tissues. The expression of HSP27 in the tissues was detected using the two-step streptavidin-peroxidase immunohistochemical method. Some collected tissues were frozen, and expressions of HSP27 mRNA were detected using fluorescence quantitative polymerase chain reaction (FQ-PCR). RESULTS: Median macroscopic and microscopic esophagitis scores in groups A' (n = 10) and B' (n = 8) were 1.0 and 1.5, and 2.0 and 2.5, respectively. There were no significant differences in the macroscopic or microscopic esophagitis scores between the two groups (Z = -0.330, P = 0.741; Z = -0.142, P = 0.887, respectively). Immunohistochemical staining showed that HSP27 was expressed in all layers of the esophageal epithelia in RE and control rats. FQ-PCR showed that HSP27 mRNA levels in the lower esophageal tissue in RE group (groups A' and B') were higher than those in control group (groups C' and D') (Z = -0.249, P = 0.001). HSP27 mRNA expression in the lower esophageal tissue was significantly different in groups B' and D' (Z = -3.027, P = 0.002). And the levels of HSP27 mRNA expression in severe RE group (microscopic esophagitis score: 3) were higher than in mild RE group (microscopic esophagitis score: 1-2) and control group (Z = -3.396, P = 0.001; Z = -3.855, P < 0.001). CONCLUSIONS: HSP27 mRNA expression in the lower esophageal tissue of rats with RE is significantly higher than in the normal controls. Although reflux is a persistent stimulating factor, increased expression of HSP27 in the lower esophageal tissue of rats with RE requires aggravated esophageal injury.

[Analysis of differences on delineation of the gross tumor volume (GTV) of nasopharyngeal carcinoma].

BACKGROUND & OBJECTIVE: Accurate delineation of tumor target volume and organ at risk based on CT simulation, is essential in modern radiotherapy planning. It is also the basic requirement to improve the treatment outcome and quality of life in nasopharyngeal carcinoma (NPC). In this study, the impact factors on delineation of the gross tumor volume (GTV) of NPC were analysis. by comparing difference among various doctors' contours. METHODS: Thirty cases of NPC treatment planning with contrast enhanced CT scan were reviewed. Primary GTV delineated by in-charged physician was defined as GTV1. Another GTV delineated by author and a radiologist was defined as GTV2, while GTV1 was concealed by the functions of the treatment planning system, the longest diameters of each axis of GTV were measured and recorded respectively as X(1), Y(1), Z(1), and X(2), Y(2), Z(2). The volumes of GTV were calculated as V1 and V2. Maximum permitted error (MPE) was 2 mm on X and Y axes and 3 mm on Z axis. Margin of each axis was compared to Coparable MPEs by matching t-test. RESULTS: The differences on axes of X, Y, Z between GTV1 and GTV2 were 2.95+/-4.33, 6.24+/-7.52, 6.25+/-9.35, respectively (P