Chitosan-assisted synthesis of 1D g-C3N4 nanorods for enhanced photocatalysis.

1D porous g-C3N4 nanorods were synthesized using chitosan as a template, offering a large surface area and enhanced visible light absorption. These nanorods exhibited a remarkable 8.3-fold increase in H2 generation rate (26.6 µmol h-1) compared to bulk g-C3N4.

π-Conjugated In-Plane Heterostructure Enables Long-Lived Shallow Trapping in Graphitic Carbon Nitride for Increased Photocatalytic Hydrogen Generation.

The relatively short-lived excited states, such as the nascent electron-hole pairs (excitons) and the shallow trapping states, in semiconductor-based photocatalysts produce an exceptionally high charge carrier recombination rate, dominating a low solar-to-fuel performance. Here, a π-conjugated in-plane heterostructure between graphitic carbon nitride (g-CN) and carbon rings (Crings ) (labeling g-CN/Crings ) is effectively synthesized from the thermolysis of melamine-citric acid aggregates via a microwave-assisted heating process. The g-CN/Crings in-plane heterostructure shows remarkably suppressed excited-state decay and increased charge carrier population in photocatalysis. Kinetics analysis from the femtosecond time-resolved transient absorption spectroscopy illustrates that the g-CN/Crings π-conjugated heterostructure produces slower exciton annihilation (τ1  = 7.9 ps) and longer shallow electron trapping (τ2  = 407.1 ps) than pristine g-CN (τ1  = 3.6 ps, τ2  = 264.1 ps) owing to Crings incorporation, both of which enable more photoinduced electrons to participate in the photocatalytic reactions, thereby realizing photoactivity enhancement. As a result, the photocatalytic activity exhibits an eightfold enhancement in visible-light-driven H2 generation. This work provides a viable route of constructing π-conjugated in-plane heterostructures to suppress the excited-state decay and improve the photocatalytic performance.

Three-dimensional surface-enhanced Raman scattering substrates constructed by integrating template-assisted electrodeposition and post-growth of silver nanoparticles.

Three-dimensional (3D) plasmonic nano-arrays can provide high surface-enhanced Raman scattering (SERS) sensitivity, good spectral uniformity and excellent reproducibility. However, it is still a challenge to develop a simple and efficient method for fabrication of 3D plasmonic nano-arrays with high SERS performance. Here we report a facile approach to construct ordered arrays of silver (Ag) nanoparticles-assembled spherical micro-cavities using polystyrene (PS) sphere template-assisted electrodeposition and post-growth. The electrodeposited small Ag nanoparticles grow into bigger stable nanoparticles during the post-growth process, which could significantly improve the SERS sensitivity. The Ag nanoparticles-assembled 3D micro-cavity array provides much more hotspots in the excitation laser beam-covered volume than the two-dimensional counterpart. The relative standard deviation (RSD) of 612 cm-1 peak of rhodamine 6G (R6G) was calculated to be 8%, and the RSD of the characteristic peak taken from substrates of different batches was less than 10%. The detectable lower concentration as low as 1 fM was achieved for an aqueous solution of R6G. Such SERS substrate also showed high sensitivity to thiram (fungicide) and paraquat (herbicide) in water with limits of detection of 0.067 nM and 2.5 nM respectively. Furthermore, it also demonstrated that SERS detection of pesticide residues on fruits can be realized, showing a potential application in rapid monitoring food safety.

Extradural transcavernous approach to cavernous sinus cavernous hemangiomas.

OBJECTIVE: Cavernous sinus cavernous hemangioma (CSCH) is a rare extra-axial vascular lesion and is difficult to be removed due to their location, propensity for profuse bleeding during surgery, and relationship to complex neurovascular structures. The purpose of this study is to report our experience of the removal of CSCHs through a completely extradural transcavernous approach. METHODS: Twelve patients with CSCH, who were operated through a purely extradural approach, were retrospectively studied. Clinical symptoms and signs, radiographic characteristics, operative techniques and outcomes of these patients were analyzed. RESULTS: Headache and visual impairment were the most common clinical symptoms, followed by facial hypesthesia and ptosis. Radiographically, CSCHs have a characteristic pattern. On computed tomography (CT) scans, CSCHs are isodense or minimally hyperdense, with an intense homogenous contrast administration. Magnetic resonance image (MRI) scans revealed well-demarcated and hypo- to isointense lesions on T1-weighted images and characteristically, markedly hyperintense lesions on T2-weighted images. The T2-weighted images showed a marked homogeneous and an intense enhancement after contrast administration. All CSCHs were treated by a completely extradural transcavernous approach. Gross total excision was achieved in all 12 patients. Post-operative complication included transient cranial nerve dysfunction for 2-3 months in eight patients, and three patients developed a permanent VI nerve palsy. The follow-up period ranged from 4 to 117 months (mean 62 months), and no patient had experienced tumor recurrence. CONCLUSION: CSCHs are rare and challenging skull base tumors. The microsurgical resection, using an extradural transcavernous approach which allows complete tumor resection with an acceptable intraoperative and postoperative complications, should be considered as a favorable choice among all treatments.

Metal-organic frameworks MIL-88A hexagonal microrods as a new photocatalyst for efficient decolorization of methylene blue dye.

Metal-organic frameworks (MOFs) MIL-88A hexagonal microrods as a new photocatalyst show an active performance for methylene blue (MB) dye decolorization using visible light. MB decolorization over the MIL-88A photocatalyst follows first-order kinetics. The addition of a H2O2 electron acceptor can markedly enhance the photocatalytic MB decoloration performance of MIL-88A. Moreover, MIL-88A showed a very stable activity for MB decoloration after four consecutive usages. Owing to the advantages of the visible light response, low cost and abundance in nature, this active MIL-88A MOF photocatalyst would have great potential for environmental purification.

Alumina hollow fiber supported ZIF-7 membranes: synthesis and characterization.

ZIF-7 membrane has been prepared on the outer surface of alumina hollow fibers by the solvothermal synthesis. The synthesis conditions, including reaction temperature, time, and solution concentration, are investigated. At the reaction temperature of 100 degrees C for 8 h, microsized ZIF-7 crystals are grown on the outer surface of the hollow fibers. A continuous and dense ZIF-7 membrane with a thickness of about 5 microm is obtained after twice crystallization at 100 degrees C for 8 h. The gas separation test indicates the as-prepared ZIF-7 membranes have intercrystalline defects as the H2/N2 ideal selectivity is less than the Knudsen diffusion. After post-modification with beta-cyclodextrin aqueous solution, the micropore defects of ZIF-7 membrane is significantly reduced and the membrane has H2/N2 ideal selectivity of 3.9. The gas permeances for H2 and N2 are almost constant from room temperature to 150 degrees C for the ZIF-7 hollow fiber membranes before and after beta-cyclodextrin modification.

Contra-diffusion synthesis of ZIF-8 films on a polymer substrate.

ZIF-8 films were successfully prepared on a flexible nylon substrate with a contra-diffusion synthesis method, and gas permeation experiments indicated that the films were continuous and compact.

[Surgical management of petroclival meningiomas invading into cavernous sinus].

OBJECTIVE: To analyze the clinical features, surgical strategy and management outcomes of petroclival meningioma invading into cavernous sinus. METHODS: Fifteen cases with petroclival meningioma invading into cavernous sinus were retrospectively analyzed. The presigmoidal approach was selected to remove tumors. The surgical strategy for tumor in cavernous sinus was partial resection combined with radiosurgery. Postoperative cranial nerve function and patient survival status were analyzed. RESULTS: The main symptoms of subtype of petroclival meningiomas were headache, abducens nerve palsy and trigeminal neuropathy. Gross total tumor removal was achieved in 13 cases and more than 90% resection in 2 cases. There was no operative death. Nine cases suffered from new postoperative cranial nerve deficits. After a follow-up of 6 - 59 months, complete improvement was achieved in oculomotor nerve deficits, much improvement in VII nerve deficit, but V and VI nerve function deficits improved slightly. The tumor progression-free survival rate was 86.7%. CONCLUSION: Rational surgical strategy to petroclival meningiomas invading into cavernous sinus should be suggested to reduce the operative morbidity and improve the survival quality of these patients.

Epidemiology of traumatic brain injury in eastern China, 2004: a prospective large case study.

BACKGROUND: Traumatic brain injury (TBI) is the leading cause of death for traumatic injury, which is the fifth highest killer in China and the highest killer in adults under 40 years of age. But, there is a lack of epidemiologic data of TBI in China during the past decade. This study aimed to investigate the epidemiologic data of TBI in eastern China, based on a prospective multicenter trial. METHODS: Data were collected from the 77 hospitals by standardized structured questionnaires in this region during the 1-year period (2004). RESULTS: A total of 14,948 of cases of traumatic brain injury were identified from 77 hospitals in eastern China. There were 11,446 men (76.6%) and 3,502 women (25.4%). Male adolescents and young adults were affected more often by brain injury. Traffic accidents (60.9%), knock on head (13.4%), and falls (13.1%) were the leading causes of patients with TBI. Approximately one-thirds of the traffic-related TBI were motorcyclists, 31% were pedestrians, and 21.9% were cyclists, whereas motor vehicle occupants only counted for 14% of the cases. The distribution of head injury severity, on the basis of Glasgow Coma Scale scores, was mild in 62%, moderate in 18.1%, and severe in 20% for all cases. The traffic accidents caused the most of severe injuries, which accounted for about 70.4%. Based on Glasgow Outcome Scale assessment, 10.8% of the patients died, 2.6% were in vegetation status, 2.2% had severe disability, 7.2% had moderate disability, and 77.3% had good recovery. And, the outcome depended on age, injury mechanism and initial Glasgow Coma Scale score. CONCLUSIONS: The prospective cohort study shows an alteration of TBI during the past decade in eastern China. It is essential to establish a standardized surveillance system of TBI incidence, risk factors, causes, and outcomes for development of new, more effective, targeted strategies to prevent TBI.