Growth of Au Hollow Stars and Harmonic Excitation Energy Transfer.

Optical excitation, subsequent energy transfer, and emission are fundamental to many physical problems. Optical antennas are ideal candidates for manipulating these processes. We extend energy transfer to second- and third-harmonic (SH and TH) fields through the collaborative susceptibility χ(n) (n = 1, 2, 3) resonances of nonlinear optical antennas. Hollow gold stars, with a broadband response covering the fundamental, SH, and TH frequencies, are synthesized as nonlinear antennas. Harmonic resonance energy transfer through a χ(3) → χ(1) collaboration is revealed. A χ(3) → χ(2) collaboration is uncovered, with largely enhanced SH radiation demonstrated by exciting the three resonances at the fundamental, SH, and TH frequencies. A theoretical model of the effective nonlinear susceptibilities is proposed to calculate the efficiencies of the two nonlinear energy transfer processes.

A Pt-free pristine monolithic carbon aerogel counter electrode for dye-sensitized solar cells: up to 20% under dim light illumination.

In this work, pristine carbon aerogels (CAs) were used as Pt-free counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) by varying the molar ratio of their precursors. Pristine mesoporous CAs with controlled resorcinol (R)/formaldehyde (F) and resorcinol (R)/sodium carbonate (C) molar ratios were successfully prepared. The as-prepared CAs were synthesized via a polymeric sol-gel reaction and were labeled as CA-O, CA-Q, CA-F, CA-C, and CA-G. The DSSCs using the as-prepared CA-C CE gave the best power conversion efficiency (PCE, η), 9.08 ± 0.01%, among all the CA CEs. The CA-C CE is further applied to an indoor T5 light source system with an impressive η value of 20.1 ± 0.60% at 2.18 mW cm-2 (T5 lamp with 7000 lux). Moreover, the hardness of CA-C CE is 3.01 GPa (Brinell hardness test), which is comparable to that of the FTO/glass substrate. As a result, the CA-C CE shows great potential to replace traditional CEs based on the Pt/FTO/glass in DSSCs.

Highly tunable nonlinear response of Au@WS2 hybrids with plasmon resonance and anti-Stokes effect.

We synthesize Au@WS2 hybrid nanobelts and investigate their third-order nonlinear responses mediated by a strong anti-Stokes effect. By using the femtosecond Z-scan technique and tuning the excitation photon energy (Eexc), we find the sign reversals of both nonlinear absorption coefficient ß and nonlinear refractive index γ to be around 1.60 eV, which is prominently higher than the bandgap (1.35 eV) of WS2 bulk owing to the strong anti-Stokes processes around the bandgap of the indirect semiconductors. The saturable absorption and self-defocusing of the WS2 nanobelts are significantly enhanced by the plasmon resonance of the Au nanoparticles when Eexc > 1.60 eV. But the excited state absorption assisted by the anti-Stokes processes and the self-focusing observed at Eexc < 1.60 eV are suppressed by the surface plasmon. Furthermore, by using population rate equations, we theoretically analyze the sign reversals of both ß and γ and reveal the physical mechanism of the unique nonlinear responses of the hybrids with the plasmon resonance and anti-Stokes effect. These observations enrich the understanding of the nonlinear processes and interactions between the plasmon and exciton and are helpful for developing nonlinear optical nanodevices.

Largely enhanced photocatalytic hydrogen production rate of CdS/(Au-ReS2) nanospheres by the dielectric-plasmon hybrid antenna effect.

In this study, we synthesized CdS/(Au-ReS2) nanospheres that have highly efficient photocatalytic hydrogen production activity induced by dielectric-plasmon hybrid antenna resonance. As the diameter (D) of ReS2 nanospheres consisting of 2D nanosheets increases from 114 ± 11 to 218 ± 25 nm, the resonance wavelength of the ReS2 dielectric antenna is tuned from 380 to 620 nm and the hydrogen production rate for the CdS/(Au-ReS2) nanospheres increases by more than 1.85 times and reaches a value as high as 3060 µmol g-1 h-1, with a 9% weight percentage of Au. Due to the enhancements of the local electromagnetic field and excitation energy transfer by the ReS2-Au dielectric-plasmon hybrid antenna, the hydrogen production rate for the CdS/(Au-ReS2) nanospheres (D = 218 ± 25 nm) is 797, 319, 105 and 12 times larger than that for pure ReS2, Au-ReS2, CdS, and CdS-ReS2, respectively. Additionally, the persistence and reusability measurements indicate a favorable stability of CdS/(Au-ReS2). These results provide a strategy to prepare a new class of dielectric-plasmon hybrid antennas consisting of 2D materials and metal nanoparticles, which have promise in applications ranging from photocatalysis to nonlinear optics.

A Highly Stable Framework of Crystalline Zinc Phosphite with Selective Removal, Recovery, and Turn-On Sensing Abilities for Mercury Cations in Aqueous Solutions.

A highly stable framework of organic-inorganic hybrid zinc phosphite (NTOU-4) and its cobalt analogue (NTOU-4a) were synthesized under the hydro(solvo)thermal conditions and structurally characterized by single-crystal X-ray diffraction. Their frameworks consisted of inorganic metallophosphite chains, in which the metal atoms were interlinked through 1H-1,2,4-triazole-3,5-diamine and 1,4-benzenedicarboxylate linkers to form new crystalline materials. It is extremely difficult to achieve the consolidation of three distinct coordinations of metal-carboxylate, metal-triazolate, and metal-phosphite bonds into one crystal, resulting in the synthesis of the first mixed-ligand terephthalate-metallophosphite solids in the absence of organic molecules as templates or space-filling counters in their structures. Interestingly, the zinc compound not only exhibits high thermal stability (up to 400 °C in air) and chemical resistance to seawater, aqueous solutions (pH 3-11), and organic solvents at boiling conditions, but also shows selective removal, recovery, and "turn-on" sensing abilities of toxic mercury ions in aqueous solutions. Furthermore, the synthesis, characterization, and the difference of the framework stabilities between isostructural zinc and cobalt compounds are also reported.

A Series of Organic-Inorganic Hybrid Zinc Phosphites Containing Extra-Large Channels.

A series of organic-inorganic hybrid zinc phosphites with extra-large channels were synthesized and characterized by single-crystal X-ray diffraction. This is an unusual example of introducing 1,4-benzenedicarboxylate and/or biphenyl-4,4'-dicarboxylate ligands into the organically templated metal phosphite system to build extra-large-channel zeolite-related materials via hydro(solvo)thermal reactions. Those frameworks are composed of carboxylate linkers and inorganic tubes of zinc phosphites, translating their channel windows from a square shape (NTOU-1) to rhombus forms (NTOU-2 and NTOU-3) via the replacement of organic amines or ligands under synthesis conditions otherwise identical with those used to prepare NTOU-1. The synthesis, structural diversity, photoluminescence, and adsorption properties for dye molecules and lanthanide ions are also reported.

Controlled growth and optical response of a semi-hollow plasmonic nanocavity and ultrathin sulfide nanosheets on Au/Ag platelets.

Herein, we report a strategy to construct a semi-hollow plasmonic nanocavity and grow ultrathin sulfide nanosheets inside. The competition and cooperation of Au deposition with Ag etching based on flat Ag nanoplates are proposed. For the establishment of the semi-hollow nanocavity, Au shells are grown on Ag nanoplates, which serve as a stable frame, followed by partial etching of the Ag nanoplates. By controlling the thickness of the initial Ag nanoplates or the injected amount of etchant, the nanocavity size is fine-tuned. Significantly, the remaining unetched Ag layers provide a flat platform for the growth of 2D ultrathin sulfides of Ag2S and CdS inside the semi-hollow plasmonic nanocavity. Strong plasmon resonance and large local field enhancement are exhibited inside the plasmonic cavity where the ultrathin semiconductor sulfides are grown, indicating strong plasmon-exciton interactions in the hybrids. Furthermore, this synthetic approach is extended to grow other metal sulfides such as Bi2S3 and PbS. The combination of a flat plasmonic cavity with ultrathin semiconductor nanosheets in this study provides a new strategy for the development of unique plasmon-based hybrids with excellent optical properties.

The nonmonotonous shift of quantum plasmon resonance and plasmon-enhanced photocatalytic activity of gold nanoparticles.

The surface plasmon resonance (SPR) of metal nanoparticles exhibits quantum behaviors as the size decreases owing to the transitions of quantized conduction electrons, but most studies are limited to the monotonous SPR blue-shift caused by off-resonant transitions. Here, we demonstrate the nonmonotonous SPR red-shift caused by resonant electron transitions and photocatalytic activity enhanced by the quantum plasmon resonance of colloidal gold nanoparticles. A maximal SPR wavelength and the largest photocatalytic activity are observed in the quantum regime for the first time for the gold nanoparticles with a diameter of 3.6 nm. Theoretical analysis based on a quantum-corrected model reveals the evolution of SPR with quantized electron transitions and well explains the nonmonotonous size-dependencies of the SPR wavelength and absorption efficiency. These findings have profound implications for the understanding of the quantum nature of the SPR of metal nanoparticles and their applications in areas ranging from photophysics to photochemistry.

Drug repositioning discovery for early- and late-stage non-small-cell lung cancer.

Drug repositioning is a popular approach in the pharmaceutical industry for identifying potential new uses for existing drugs and accelerating the development time. Non-small-cell lung cancer (NSCLC) is one of the leading causes of death worldwide. To reduce the biological heterogeneity effects among different individuals, both normal and cancer tissues were taken from the same patient, hence allowing pairwise testing. By comparing early- and late-stage cancer patients, we can identify stage-specific NSCLC genes. Differentially expressed genes are clustered separately to form up- and downregulated communities that are used as queries to perform enrichment analysis. The results suggest that pathways for early- and late-stage cancers are different. Sets of up- and downregulated genes were submitted to the cMap web resource to identify potential drugs. To achieve high confidence drug prediction, multiple microarray experimental results were merged by performing meta-analysis. The results of a few drug findings are supported by MTT assay or clonogenic assay data. In conclusion, we have been able to assess the potential existing drugs to identify novel anticancer drugs, which may be helpful in drug repositioning discovery for NSCLC.

[Experience of surgical treatment of carotid body tumor after preoperative embolization of feeding vessels].

OBJECTIVE: To evaluate the effect of preoperative embolization of the feeding vessels of carotid body tumor in the treatment thereof. METHODS: 33 patients with carotid body tumors not less than 3 cm in diameter were examined by color Doppler ultrasound. Polyvinyl alcohol particle 250-1000 microm in diameter were suspended in meglumine diatrizoate or Ultravist and then injected via microcatheter into the feeding vessels until detainment or reflux was seen. Operation was performed 1 day later on 23 patients and 4 days later on 10 patients. External carotid artery to internal carotid artery bypass was performed on 1 case, anastomosis of common carotid to internal carotid artery with auto-saphenous vein interposition on 3 cases, and repair of internal carotid artery on 1 case. RESULTS: One-stage resection was completed on all tumors. One case suffered contralateral hemiplegia two times in the operative day, on the next day the contralateral lower limb could move, but the patient could not speak clearly and his tongue was not in right position, after 3 months he was completely recovered and MRI illustrated cranial infarction. CONCLUSION: An important adjunct in treating large carotid body tumor, preoperative embolization makes the surgical exploration proceed much smoother, blood loss become less, and morbidity lower.

[Effects on the survival of rat's abdominal axial skin flap after the combination of VEGF gene therapy and skin flap delay].

OBJECTIVE: To investigate the effect of VEGF (vascular endothelial growth factor) gene therapy and skin flap delay on the survival of rat's abdominal axial skin flap. METHODS: In 48 Wistar rats, the model of a abdominal axial skin flap supplied by right superficial epigastric vessel was created. The rats were divided into six groups. The group was treated with subcutaneous injection of pcDNA4-VEGF165, skin flap delay or VEGF injection combined with skin flap delay. 7 days later, the survival rate of the skin flap was measured; specimens were harvested from the skin flap for histological investigation of the microvessels and for immunohistochemical staining to observe the expression of VEGF. RESULTS: Every treated group was significantly higher than blank group in the average survival rate of the skin flap and group V (gene injection when delayed) has the highest one. The average number of the microvessels in group II, III, V, VI was significantly higher than group IV and blank group. Group IV > group V, VI > group II, III > blank group in lumen diameter of the microvessels. Immunohistochemical staining documented more deposition of VEGF DNA in group II, III, V, VI than group IV and blank group. CONCLUSIONS: Both administration of pcDNA4-VEGF165 and skin flap delay can improve the survival of rat's abdominal axial skin flap, but the mechanisms of the effect were different. The combination of the two ways has stronger effect.

[The epidemiology character of the 503 residual paralysis of acute flaccid paralysis cases].

OBJECTIVE: Analyze the epidemiology character of the residual paralysis(RP) of acute flaccid paralysis (AFP) in Guangdong during 1994-2007. METHODS: The viruses isolated from the excrement of RP cases were identified and typed in Guangdong from 1994 to 2007. Statistics analysis was performed to reveal the relationship among the immunization history,age,gender and the distribution of the etiology. RESULTS: A total of 503 RP cases were reported. 150 of which were isolated with PV and 59 were isolated with NPEV. From 1994 to 2007, The PV isolating rate ranged from 18.92% to 47.06% and was higher in winter and spring, while the NPEV isolating rate ranged from 4.17% to 25.00%. and was higher in summer and autumn. The PV isolating rate decreased as the age increased,and its isolating rate (61.11%) was highest in "0" year group. The PV isolating rate of the population of < or =2 times OPV was far higher than 3 times. The PV and NPEV isolating rate of the RP cases was higher than without RP. CONCLUSION: The case with RP caused by wild poliovirus wasn't found from 1994 to 2007 in Guangdong, but the relationship of RP case was observed between < or =2 years group and < or =1 time OPV, and NPEVs probably are the potential etiological agent that cause children RP.

[Endovascular stent-graft repair for Stanford type A aortic dissection with extra-anatomic bypass].

UNLABELLED: OBJECTIVE To evaluate the effects of endovascular stent-graft repair for Stanford type A aortic dissection combined with extra-anatomic bypass. METHODS: To perform endovascular repair for Stanford type A aortic dissection, we tried to extend the landing zone by extra-anatomic bypass to reconstruct the innominate artery, the left common carotid artery or the left subclavian artery, and then achieved the process immediately or at a secondary stage via either the carotid or the femoral approach. RESULTS: Thirty-four patients with ascending aortic dissection (n=8) and aortic arch dissection (n=26) were treated with this technique. Thirty three patients were successfully done aortic endovascular repair, only one died during the operation. The thirty-day mortality rate was 8.8% (3/34), endoleak incidence rate was 11.8% (4/34) and incidence rate of cerebral infarction was 5.9% (2/34). Twenty-nine patients were followed-up for 6-70 months (mean, 24. 5 months). Complete (n=16) and partial (n=13) thrombosis of the false lumen were showed with CT angiography and/or vascular color Doppler ultrasound scanning. CONCLUSIONS: Endovascular stent-graft repair combined with extra-anatomic bypass can be a novel option for Stanford type A aortic dissection; it is safe, less invasive, and with fewer complications. Nevertheless, indications need further consideration.

[Clinical analysis of mesenteric venous thrombosis:a report of 23 cases].

OBJECTIVE: To assess the early clinical diagnosis and treatment of mesenteric venous thrombosis (MVT). METHODS: Clinical data of 23 cases with MVT from January 1994 to December 2003 were analyzed retrospectively. RESULTS: There were 17 males and 6 females, the age ranged from 19 to 74 years old with a mean age of 42 years. Of them, 20 patients presented acute MVT. The main symptoms included abdominal pain and distention, nausea, vomiting, and bloody stool. The detect able rates of transabdominal color Doppler ultrasonography and CT for MVT were 94.1% and 100% respectively. Nine of 11 (81.8%) patients were cured with non-surgical management. Twelve patients underwent surgical treatments including resection of the infarcted bowel and open mesenteric venous thrombectomy with Fogarty catheter via a branch of mesenteric vein. The in-hospital mortality rate was 8.7%, and the postoperative morbidity rate was 33.3%, including ascites in 2 patients and postprandial abdominal pain in other 2 patients. After follow-up from 2 months to nine years, 3 patients had MVT recurrence because of ceasing anti-coagulation treatment and 3 died of myocardial infarction, liver cancer and hepatic cirrhosis. CONCLUSION: Color Doppler ultrasonography and CT scanning are valuable diagnostic methods for MVT, and anticoagulation treatment and operation are effective managements.

Endovascular stent-graft repair of aortic dissection.

Between October 2000 and January 2002, 9 consecutive male patients with subacute or chronic aortic dissection underwent stent-graft placement. The indication for surgery was continuous pain or aneurysm development. One patient had a type A dissecting aortic aneurysm with a primary tear in the ascending thoracic aorta; the other 8 had type B dissection. Placement of an endovascular stent-graft was technically successful in 8 patients, and one underwent an open procedure for abdominal aortic fenestration. The entry site was sealed and the false lumen disappeared in 8 cases, and thrombosis of the false lumen was obtained. Rupture of an iliac artery dissecting aneurysm occurred in one patient 2 days after stent-graft placement; abdominal aortic fenestration with prosthetic replacement of the distal abdominal aorta was performed. One patient died of myocardial infarction 3 days after the stent-graft procedure. During a mean follow-up period of 7 months (1-16 months), one patient died of acute myocardial infarction at 11 months. It was concluded on the basis of these short-term results that endovascular repair of aortic dissection is a promising treatment, and abdominal aortic fenestration is a useful adjuvant procedure.