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The high porosity and versatile structures of metal–organic frameworks (MOFs) as new theranostic platforms have drawn broad attention and have been widely explored. This has inspired the use of MOFs to encapsulate various functional nanoparticles within the frameworks to further develop and extend the biomedical applications in drug delivery and bioimaging. Herein, we fabricated yolk–shell magnetic composites Fe3O4@Co/Zn-ZIF towards magnetic resonance (MR) imaging-guided chemotherapy by combining a controlled encapsulation process with a mild phase transformation under solvothermal conditions. The designed yolk–shell composites Fe3O4@Co/Zn-ZIF exhibited high doxorubicin (DOX) loading capacity, pH-responsive release characteristics, good biocompatibility and strong T2-weighted MR imaging contrast enhancement. The hollow structure Co/Zn-ZIF serving as a shell could collapse under low pH conditions, and achieved controlled release of drugs. Dopamine-modified Fe3O4 nanoparticles (Fe3O4–DA NPs) as the core could confer Fe3O4@Co/Zn-ZIF with outstanding MR imaging capacity and facile magnetic separation. This strategy sheds light on a new way to develop multifunctional drug delivery systems by using hollow structures of MOFs as hosts for different functional nanoparticles. [ABSTRACT FROM AUTHOR]

2,2,7,7-Tetrakis-(N,N-di-p-methoxyphenylamine)9,9-bifluorene (Spiro-OMeTAD) is a widely employed hole-transporting layer (HTL) in typical n-i-p structure perovskite solar cells (PSCs). And the p-type dopants of bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI) and tert-butylpyridine (tBP) have to be utilized to improve the hole mobility and film conductivity of Spiro-OMeTAD. However, the incorporation of these additives will cause the issue of deliquescence, strongly speeding up the degradation of the Spiro-OMeTAD layer and thus of the perovskite layer. Herein, we developed a modified Spiro-OMeTAD layer using MoS2 with the 2H semiconducting phase and flower-like microstructure. The addition of MoS2 played an important role in improving the hole mobility and enhancing the film stability of Spiro-OMeTAD. The resulting PSCs based on the MoS2-modified Spiro-OMeTAD HTL delivered a champion power conversion efficiency as high as 20.18%. More importantly, the incorporation of MoS2 could suppress the Li+ migration in the HTL owing to the strong adsorption ability and large specific surface area of flower-like MoS2 nanoparticles. As a result, the fabricated PSC without encapsulation exhibited promising stability by retaining almost 85% of the initial PCE even after 300 h exposure to air while the reference device only retained about 30% of its initial PCE. [ABSTRACT FROM AUTHOR]

Abstract: Organometallic halide perovskite films with good surface morphology and large grain size are desirable for obtaining high‐performance photovoltaic devices. However, defects and related trap sites are generated inevitably at grain boundaries and on surfaces of solution‐processed polycrystalline perovskite films. Seeking facial and efficient methods to passivate the perovskite film for minimizing defect density is necessary for further improving the photovoltaic performance. Here, a convenient strategy is developed to improve perovskite crystallization by incorporating a 2D polymeric material of graphitic carbon nitride (g‐C3N4) into the perovskite layer. The addition of g‐C3N4 results in improved crystalline quality of perovskite film with large grain size by retarding the crystallization rate, and reduced intrinsic defect density by passivating charge recombination centers around the grain boundaries. In addition, g‐C3N4 doping increases the film conductivity of perovskite layer, which is beneficial for charge transport in perovskite light‐absorption layer. Consequently, a champion device with a maximum power conversion efficiency of 19.49% is approached owing to a remarkable improvement in fill factor from 0.65 to 0.74. This finding demonstrates a simple method to passivate the perovskite film by controlling the crystallization and reducing the defect density. [ABSTRACT FROM AUTHOR]

Abstract: Great efforts toward developing novel and efficient hole‐transporting materials are needed to further improve the device efficiency and enhance the cell stability of perovskite solar cells (PSCs). The poor film conductivity and the low carrier mobility of organic small‐molecule‐based hole‐transporting materials restrict their application in PSCs. This study develops an efficient and stable hole‐transporting material, tetrafluorotetracyanoquinodimethane (F4‐TCNQ)‐doped copper phthalocyanine‐3,4′,4′′,4′′′‐tetra‐sulfonated acid tetra sodium salt (TS‐CuPc) via a solution process, in planar structure PSCs. The p‐type‐doped TS‐CuPc film demonstrates improved film conductivity and hole mobility owing to the strong electron affinity of F4‐TCNQ. By the F4‐TCNQ tailoring, the composite film gives the highest occupied molecular orbital level as high as 5.3 eV, which is beneficial for hole extraction. In addition, the aqueous solution processed TS‐CuPc:F4‐TCNQ precursor is almost neutral with good stability for avoiding the electrode erosion. As a result, the fabricated PSCs employing TS‐CuPc:F4‐TCNQ as the hole‐transporting material exhibit a power conversion efficiency of 16.14% in a p–i–n structure and 20.16% in an n–i–p structure, respectively. The developed organic small molecule of TS‐CuPc provides the diversification of hole‐transporting materials in planar PSCs. [ABSTRACT FROM AUTHOR]

The electron‐transporting layer (ETL) plays a critical role in improving the charge extraction and suppressing the carrier recombination in planar perovskite solar cells (PSCs). Compact titanium dioxide (TiO2) film is a widely used as an ETL in conventional n‐i‐p PSCs. However, there is still much room for improvement in the electron mobility and reducing the oxygen vacancies of the compact TiO2 film. Herein, Pt‐doped TiO2 film with outstanding electron‐transporting property and complete coverage on the substrates is reported by the authors. Pt‐doping results in a tailed band level of TiO2, which could suppress the charge accumulation at the interface of TiO2‐Pt/perovskite. Consequently, TiO2‐Pt ETL based PSCs deliver a power conversion efficiency as high as 20.05% with an open‐circuit voltage of 1.15 V, a fill factor of 0.75, a short‐circuit current density of 23.83 mA cm−2 and remarkably alleviated hysteresis behavior. Chloroplatinic acid (H2PtCl6) is incorporated into the TiO2 precuror to improve the electrical properties of a compact TiO2 film with the aim to improve the charge carrier extraction and injection efficiency in n‐i‐p perovskite solar cells. As a result, the resulting perovskite solar cells presented a maximum power conversion efficiency as high as 20.05% owing to the obvious improvements of open‐circuit voltages (1.15 V) and fill factor (0.75). [ABSTRACT FROM AUTHOR]

Single-crystal membranes (SCMs) show great promise in the fields of sensors, light-emitting diodes, and photodetection. However, the growth of a large-area single-crystal membranes is challenging. We report a new organic-inorganic SCMs [HCMA] 2 CuBr 4 (HCMA = cyclohexanemethylamine) crystallized at the gas-liquid interface. It also has low-temperature ferromagnetic order, high-temperature dielectric anomalies, and narrow band gap indirect semiconductor properties. Specifically, the reversible phase transition of the compound occurs at 350/341 K on cooling/heating and exhibits dielectric anomalies and stable switching performance near the phase transition temperature. The ferromagnetic exchange interaction in the inorganic octahedra and the organic layer enables ferromagnetic ordering at low-temperature 10 K. Finally, the single crystal exhibits an indirect semiconducting property with a narrow band gap of 0.99 eV. Such rich multichannel physical properties make it a potential application in photodetection, information storage and sensors.

Perovskite film-quality is a crucial factor to improve the photovoltaic properties of perovskite solar cells, which is closely related to the morphology of crystallization grain size of the perovskite layer. However, defects and trap sites are inevitably generated on the surface and at the grain boundaries of the perovskite layer. Here, we report a convenient method for preparing dense and uniform perovskite films, employing g-C 3 N 4 quantum dots doped into the perovskite layer by regulating proper proportions. This process produces perovskite films with dense microstructures and flat surfaces. As a result, the higher fill factor (0.78) and a power conversion efficiency of 20.02% are obtained by the defect passivation of g-C 3 N 4 QDs., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Purpose: To compare the short-term clinical effect and to assess the influencial factors of immediate implant placement and delayed implant placement around single-tooth implant in the aesthetic area., Methods: A total of 114 patients requiring a single-tooth implant in the aesthetic area were reviewed at Center for Implant Dentistry of Stomatological Hospital of China Medical University. They were divided into immediate implant group and delayed implant group. The patients were followed up for 1 year after upper structure rehabilitation, and the pink esthetic score and the marginal bone absorption around the implants were measured. Statistical analysis was performed using SPSS 17.0 software package., Results: After 1 year of upper structure rehabilitation, 114 implants were stable and the marginal bone absorption around the implants of the immediate implant group was (0.36±0.39) mm,significantly smaller than the delayed implant group [(0.79±0.67)mm, P<0.001]. The difference in PES score between the two groups were not statistically significant on the day of rehabilitation and 1 year after upper structure rehabilitation（P>0.05）. Significant improvement of PES on the day of rehabilitation and 1 year after upper structure rehabilitation and marginal bone absorption was found with flapless surgery. SLA and DAE surface treatment methods had no significant impact on PES and marginal bone absorption (P>0.05). Graft procedure had an unfavorable effect on PES value both on the day of rehabilitation and 1 year after upper structure rehabilitation., Conclusions: Under appropriate indications, immediate implant placement and immediate repair could reduce the time of missing teeth. The marginal bone absorption of immediate implant group is smaller than delayed implant group. Flapless surgery avoids damage to gingival tissue, reduces postoperative reaction and improves the aesthetic outcomes after repair.

Deep brain stimulation of the subthalamic nucleus is recognized as the most effective treatment for moderate and advanced Parkinson's disease. Programming of the stimulation parameters is important for maintaining the efficacy of deep brain stimulation. Voltage is considered to be the most effective programming parameter. The present study is a retrospective analysis of six patients with Parkinson's disease (four men and two women, aged 37-65 years), who underwent bilateral deep brain stimulation of the subthalamic nucleus at the First Affiliated Hospital of Sun Yat-sen University, China, and who subsequently adjusted only the stimulation voltage. We evaluated motor symptom severity using the Unified Parkinson's Disease Rating Scale Part III, symptom progression using the Hoehn and Yahr scale, and the levodopa equivalent daily dose, before surgery and 1 and 2 years after surgery. The 2-year follow-up results show that rigidity and tremor improved, and clinical symptoms were reduced, while pulse width was maintained at 60 μs and frequency at 130 Hz. Voltage adjustment alone is particularly suitable for patients who cannot tolerate multiparameter program adjustment. Levodopa equivalent daily dose was markedly reduced 1 and 2 years after surgery compared with baseline. Our results confirm that rigidity, tremor and bradykinesia can be best alleviated by voltage adjustment. The trial was registered at ClinicalTrials.gov (identifier: NCT01934881)., Competing Interests: The abstract as written communication was presented at the 18th Zhongshan International Neurology Summit Conference at November 28, 2015

Microalgae based biodiesel production requires a large amount of lipid accumulation in the cells, and the accumulation is greatly influenced by the environment. Therefore, it is necessary to find fast and non-destructive methods for lipid change detection. In this paper, Chlorella sp. was adopted as the objective, which was cultured under different light condition consisted of red and blue lights with different proportion. We applied the visible near-infrared spectroscopy (Vis/NIRs) technique to detect the dynamic change of lipid during the microalgae growth processes and utilized hyperspectral imaging technology for visualization of lipid distribution in the suspension. The transmittance and reflectance spectra of microalgae were acquired with Vis/NIRs and hyper-spectroscopy, respectively. In the comparison of the transmittance and reflectance spectra, they showed some different characteristics. Meanwhile it also varied in terms of the number and the area of feature wavelengths obtained by successive projections algorithm (SPA) based on the different spectra. But the established multiple linear regression (MLR) model for lipid content prediction had similar results with rpre of 0.940, RMSEP of 0.003 56 and rpre of 0.932, RMSEP of 0.004 23, respectively. Based on the predictive model, we obtained the spectra and analyzed the lipid dynamic change in microalgae in one life cycle. In the life cycle, the lipid content in Chlorella sp. was relatively stable from the beginning of inoculation to exponential phase, the increase and accumulation of lipid phenomenon occurred in the late exponential phase. Combined with the MLR model and the hypersepctral images, we studied the visualization result of microalgae suspension in the steady phase. The stimulated images showed that the microalgae with higher lipid content appeared gathering. This study compared the difference and the feasibility of the Vis/NIRs and hyperspectral imaging technique in lipid content detection applied in microalgae growing microalgae. The results are meaningful for the fast and non-destructive detection of the growth information of microalgae. It has boththeoretical and practical significance for developing microalgal culture and harvest strategy in practice.

Effective cultivation of the microalgae is the key issue for microalgal bio-energy utilization. In nutrient rich culture conditions, the microalge have a fast growth rate, but they are more susceptible to environmental pollution and influence. So to monitor the the growth process of microalgae is significant during cultivating. Hyperspectral imaging has the advantages of both spectra and image analysis. The spectra contain abundant material quality signal and the image contains abundant spatial information of the material about the chemical distribution. It can achieve the rapid information acquisition and access a large amount of data. In this paper, the authors collected the hyperspectral images of forty-five samples of Chlorella sp., Isochrysis galbana, and Spirulina sp., respectively. The average spectra of the region of interest (ROI) were extracted. After applying successive projection algorithm (SPA), the authors established the multiple linear regression (MLR) model with the spectra and corresponding biomass of 30 samples, 15 samples were used as the prediction set. For Chlorella sp., Isochrysis galbana, and Spirulina sp., the correlation coefficient of prediction (r(pre)) are 0.950, 0.969 and 0.961, the root mean square error of prediction (RMSEP) for 0.010 2, 0.010 7 and 0.007 1, respectively. Finally, the authors used the MLR model to predict biomass for each pixel in the images of prediction set; images displayed in different colors for visualization based on pseudo-color images with the help of a Matlab program. The results show that using hyperspectral imaging technique to predict the biomass of Chlorella sp. and Spirulina sp. were better, but for the Isochrysis galbana visualization needs to be further improved. This research set the basis for rapidly detecting the growth of microalgae and using the microalgae as the bio-energy.