Spin-liquid-like state in pure and Mn-doped TbInO3 with a nearly triangular lattice

Inelastic neutron scattering studies in single crystals of TbInO3 and TbIn0.95Mn0.05O3 with nearly triangular antiferromagnetic lattice are reported. At low energies, a broad and apparently gapless continuum of magnetic excitations, located at the triangular lattice (TL) Brillouin zone boundary, is observed. The data are well described by the uncorrelated nearest-neighbor valence bonds model. At higher energies, a broad excitation branch dispersing from the TL zone boundary is observed. No signs of static magnetic order are found down to the temperatures two orders of magnitude smaller than the effective interaction energy. The fluctuating magnetic moment exceeds two-thirds of the Tb3+ free-ion value and is confined to the TL plane. These observations are consistent with a TL-based spin liquid state in TbInO3.

Spin Stripe Order in a Square Planar Trilayer Nickelate

Trilayer nickelates, which exhibit a high degree of orbital polarization combined with an electron count (d^{8.67}) corresponding to overdoped cuprates, have been identified as a promising candidate platform for achieving high-T_{c} superconductivity. One such material, La_{4}Ni_{3}O_{8}, undergoes a semiconductor-insulator transition at ∼105  K, which was recently shown to arise from the formation of charge stripes. However, an outstanding issue has been the origin of an anomaly in the magnetic susceptibility at the transition and whether it signifies the formation of spin stripes akin to single layer nickelates. Here we report single crystal neutron diffraction measurements (both polarized and unpolarized) that establish that the ground state is indeed magnetic. The ordering is modeled as antiferromagnetic spin stripes that are commensurate with the charge stripes, the magnetic ordering occurring in individual trilayers that are essentially uncorrelated along the crystallographic c axis. A comparison of the charge and spin stripe order parameters reveals that, in contrast to single-layer nickelates such as La_{2-x}Sr_{x}NiO_{4} as well as related quasi-2D oxides including manganites, cobaltates, and cuprates, these orders uniquely appear simultaneously, thus demonstrating a stronger coupling between spin and charge than in these related low-dimensional correlated oxides.

TFAP2B overexpression contributes to tumor growth and progression of thyroid cancer through the COX-2 signaling pathway

Thyroid cancer is commonly seen in the clinic with a rapidly increasing incidence globally. COX-2 overexpression correlates with the pathologic type of thyroid carcinoma, and it has been suggested that COX-2 overexpression is associated with a poor prognosis. However, little is known about its upstream regulatory mechanism. Bioinformatics suggested that transcription factor AP-2 beta (TFAP2B) might specifically bind to the COX-2 promoter, which was confirmed by biotin-labeled COX-2 promoter pulldown and luciferase reporter assays. We performed western blot and immunohistochemical staining to detect the expression of TFAP2B/COX-2 in thyroid cancer tissues (T) and the matched adjacent noncarcinoma tissues (ANT), and investigated the relationship between TFAP2B/COX-2 expression and clinical pathological factors in thyroid cancer patients. Afterward, MTS, colony formation, cell-apoptosis assay, transwell-invasion and scratch assays were performed to examine the proliferation, apoptosis, invasion, and migration of thyroid cancer cells with TFAP2B knocked down or overexpressed. The mouse xenograft experiment was performed to study in vivo the proliferation of thyroid cancer cells with TFAP2B knocked down or overexpressed. We found that TFAP2B bound to the promoter of COX-2 to activate its expression. Western blot and immunohistochemistry showed that TFAP2B/COX-2 was highly expressed in thyroid cancer, and high TFAP2B and COX-2 expression was associated with aggressive clinicopathological features in thyroid cancer. TFAP2B mediated thyroid cancer cell proliferation, apoptosis, invasion, and migration via the COX-2 signaling pathway in vitro and in vivo. TFAP2B bound to the promoter of COX-2 to activate its expression, indicating that TFAP2B is a critical regulatory molecule in the COX-2 signaling pathway that promoted tumor progression in thyroid cancer.

Weighted gene co-expression network analysis and prognostic analysis identifies hub genes and the molecular mechanism related to head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a lethal disease with suboptimal survival outcomes. In this study, we aimed to find an independent prognostic factor of head and neck squamous cell carcinoma and investigate its effect on tumor cell proliferation, apoptosis, migration progress and cell cycle phase. Weighted gene co-expression network analysis (WGCNA) is an analysis method for mining module information in chip data through soft threshold. In this article, it was used to divide differential genes into different modules and determined the ten hub genes. Overall survival (OS) and disease-free survival (DFS) analyses as well as univariate and multivariate regression analyses were used to figure out HMGA2 as the independent prognostic factor. RT-qPCR and western blot results revealed the HMGA2 expression levels. Via colony formation, flow cytometry and wound healing assays, we tested the involvement of HMGA2 knockdown in corresponding cancer cell biological behaviors. HMGA2 level was up-regulated in HNSCC tissues and cell lines (SCC-25 and FaDu) in comparison with their normal counterparts. HMGA2 knockdown decreased cancer cell proliferation, promoted cell apoptosis, blocked cell cycle at G0/G1 phase, and inhibited cell migration. We regarded HMGA2 as a potential diagnostic and therapeutic target of HNSCC.

Using Instrument-Guided Team Reflection and Debriefing to Cultivate Teamwork Knowledge, Skills, and Attitudes in Pre-Clerkship Learning Teams

Drawing on the science of teamwork and the science of learning, we designed an instrument-guided team reflection and debriefing activity to foster teamwork knowledge, skills, and attitudes (KSAs) in medical students. We then embedded this activity within and between a biweekly series of pre-clerkship Team-Based Learning sessions with the goal of encouraging medical students to cultivate a practical and metacognitive appreciation of eight foundational teamwork KSAs that are applicable to both healthcare teams and classroom learning teams. On evaluations, 144 learners from a class of 156 reported increased appreciation for and team improvement with these teamwork KSAs.

Preoperative MR Imaging to Differentiate Chordoid Meningiomas from Other Meningioma Histologic Subtypes

BACKGROUND AND PURPOSE

Chordoid meningiomas are uncommon WHO grade II primary intracranial neoplasms that possess unique chordoid histology and follow an aggressive clinical course. Our aim was to assess the utility of qualitative MR imaging features and quantitative apparent diffusion coefficient values as distinguishing preoperative MR imaging metrics to identify and differentiate chordoid histology from other meningioma histologic subtypes.

MATERIALS AND METHODS

Twenty-one patients with meningiomas with chordoid histology, which included both chordoid meningiomas (>50% chordoid histology) and meningiomas with focal chordoid histology (<50% chordoid histology) with available preoperative MR imaging examinations, including diffusion-weighted imaging, were identified. Qualitative imaging features and quantitative ADC values were compared between meningiomas with chordoid histology and 42 nonchordoid meningiomas (29 WHO grade I, eleven WHO grade II, and 2 WHO grade III).

RESULTS

The median ADC (10^-3mm²/s) of meningiomas with chordoid histology was significantly higher than nonchordoid meningiomas (1.16 versus 0.92, P < .001), as was the median normalized ADC (1.60 versus 1.19, P < .001). In subgroup analysis, the median and normalized ADC values of chordoid meningiomas (n = 11) were significantly higher than those in meningiomas with focal chordoid histology (n = 10, P < .001 and P < .001, respectively) or nonchordoid meningiomas (n = 42, P < .001 and <0.001, respectively). Median and normalized ADC values were not significantly different between the meningiomas with focal chordoid histology and nonchordoid meningiomas (P = .816 and .301, respectively). Among the qualitative imaging features, only DWI signal intensity was significantly associated with meningiomas with chordoid histology diagnosis.

CONCLUSIONS

ADC values are higher in chordoid compared with nonchordoid meningiomas and may be used to discriminate the degree of chordoid histology in meningiomas. While qualitative MR imaging features do not strongly discriminate chordoid from nonchordoid meningiomas, DWI may allow preoperative identification of chordoid meningiomas.

[Comparison of two serological methods in screening gastric cancer and its precancerous condition]

Objective: To compare the diagnostic value of the old "ABC" method [serum pepsinogen(PG) combined with Helicobacter pylori (Hp) IgG antibody] and the new "ABC" method [serum pepsinogen plus gastrin-17(G-17)] in screening gastric cancer and its precancerous condition. Methods: Serum PG, G-17 and Hp-IgG were quantified by enzyme-linked immunosorbent assay (ELISA) in 278 subjects. Subjects were grouped according to the criteria of two methods. The gastroscopy and pathological biopsy were gold standard. Results: The positive rate of old "ABC" method was 74.46% (207/278), which was 54.68% of new "ABC" method (151/278). For the diagnosis of gastric cancer, the sensitivity and specificity of the old "ABC" method were 90.74% and 29.46% respectively, with diagnostic coincidence rate 41.37%. The sensitivity and specificity of the new "ABC" method were 92.59% and 54.46% respectively, with diagnostic coincidence rate 61.87%. As to the diagnosis of pre-cancerous state, the sensitivity and specificity of the old "ABC" method were 75.81% and 36.00%, with diagnostic coincidence rate 58.03%. The sensitivity and specificity of the new "ABC" method were 62.10% and 75.00%, with diagnostic coincidence rate 67.86%. Conclusions: Compared with the old "ABC" method, the new "ABC" method has higher sensitivity, specificity and diagnostic coincidence rate for the diagnosis of gastric cancer, yet higher specificity and lower sensitivity for the diagnosis of precancerous conditions.

Inkjet Printable and Self-Curable Disperse Dyes/P(St-BA-MAA) Nanosphere Inks for Both Hydrophilic and Hydrophobic Fabrics

Low-water-soluble disperse dyes possess a broad color gamut and good durability, but they need chemical or physical modification before being used in inks and can only be applied to several kinds of hydrophobic fabrics. In this work, disperse dyes/P(St-BA-MAA) nanospheres (known as DPN) absorbed by sodium nitrilotriacetate (known as NTA@DPN) were prepared and applied into ink formulations, which exhibited high dye fixation, long-term stability and self-curable ability without addition of any binder. Transmission electron microscopy (TEM) images showed the nanospheres have homogeneous core-shell spherical shape and the average diameter increased by 20.6 nm after coloration. X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), and differential scanning calorimetry (DSC) measurements illustrated the interaction between dyes and nanospheres and indicated that the colored nanospheres contained both dye molecules and crystalline dyes. The Zeta potential and particle size measurements demonstrated that the dispersion stability was improved when sodium nitrilotriacetate (NTA) was absorbed onto DPN. The rheological behavior of the NTA@DPN inks was Newtonian and desired droplet formation was achieved at the viscosity of 4.23 mPa·s. Both hydrophilic cotton and hydrophobic polyester fabrics were cationic modified before used, which had an excellent image quality and desired rubbing fastness after inkjet printing. Scanning electron microscope (SEM) images showed NTA@DPN formed stable deposits on the surface of modified fibers and could self-cure to form continuous film coating on the fiber surface after being baked at 150 °C without addition of any binder.

Side-Chain-Promoted Benzodithiophene-based Conjugated Polymers toward Striking Enhancement of Photovoltaic Properties for Polymer Solar Cells

In this work, we have reported a highly efficient photovoltaic material, PBDTTz-SBP, by fine-tuning the side chains of the benzodithiophene (BDT) unit. With the replacement of alkoxy chains with alkylthio chains, a large increase in power conversion efficiency (PCE) was realized. Non-fullerene polymer solar cells (PSCs) without any post-treatment generate an optimal PCE of up to 12.09%, with a high V_OC of 0.914 V, J_SC of 18.52 mA cm^-2, and fill factor of 71.43%. Notably, the efficiency of a PBDTTz-SBP-based solar cell was about 1.31-fold of the PCE (9.20%) of its counterpart based on the polymer, PBDTTz-BP, with alkoxy chains, indicating the striking modulation effect of side-chain engineering. Although V_OC and J_SC were lower than those of non-fullerene devices, the PSCs with PC₇₁BM as the acceptor exhibited a fairly high fill factor of up to 76.69%, affording a moderate PCE. Our work reported a highly efficient polymer solar cell with a PCE of 12.09% and clearly demonstrated the great tuning effect of alkylthio chains on photovoltaic performance.

[Clinical outcomes of gastric cancer patients received capecitabine based adjuvant chemotherapy and the corresponding pharmacogenomics analysis]

Objective: To investigate the association between Thymidine phosphorylase(TYMP)genetic variation and clinical outcomes of postoperative gastric cancer (GC) patients received capecitabine based regimens. Methods: A total of 198 GC patients underwent surgical treatment and received capecitabine based adjuvant chemotherapy were included in this retrospective study. Peripheral blood and the postoperative tissue specimen of the GC patients were collected for the genotyping of polymorphism and TYMP mRNA expression, respectively. The correlation between polymorphism and clinical outcomes and safety of postoperative GC patients were analysed. Results: Located in the upstream, rs11479 was of clinical significance. The prevalence of rs11479 in TYMP among the GC patients were as follows: CC genotype 125 cases (63.13%), CT genotype 65 cases (32.83%), TT genotype 8 cases (4.04%), minor allele frequency of rs11479 is 0.20. The distribution of three genotypes were in accordance with Hardy-Weinberg Equilibrium (P=0.901). The analysis results of patients with different genotypes found that the 3-year disease free survival rate of the patients with CT/TT genotype and CC genotype were 73.97% and 65.60%, respectively, which was statistically significant (P=0.003). In terms of overall survival, the 3-year overall survival rate of the two genotypes were 83.56% and 72.80% (P=0.012), respectively. Adjusted in multivariate Cox regression analysis, CT/TT genotype was an independent favorable factor for disease free survival (OR=0.55, P=0.011). Safety analysis indicated that there was no significant association between genotypes and grade 2 adverse reaction. Additionally, of the 79 postoperative tissue specimens, the results showed that the expression of TYMP in cancer tissues of the patients with CT/TT genotypes were significantly higher than those of the wild type CC genotype patients (P<0.001). Conclusion: The polymorphism rs11479 of TYMP have favorable influence on the clinical outcomes of gastric cancer patients received capecitabine based adjuvant chemotherapy treatment through changing the mRNA expression of TYMP.

Odd-skipped related transcription factor 1 (OSR1) suppresses tongue squamous cell carcinoma migration and invasion through inhibiting NF-κB pathway

Tongue squamous cell carcinoma (TSCC) is the most common cancers of oral, owing to the high invasive and metastatic ability, patients with TSCC have poor prognosis, it's important to explore the regulatory mechanism of TSCC invasion and metastasis. Previous studies suggest OSR1 suppresses the progression of gastric cancer and renal cell carcinoma, but its role in TSCC hasn't been studied. Here, we found OSR1 was downregulated in TSCC cells and specimens, Transwell and 3D spheroid invasion assay suggested OSR1 overexpression inhibited TSCC cell migration and invasion, while its knockdown promoted TSCC cell migration and invasion. Mechanism analysis found OSR1 expression was negatively correlated with NF-κB pathway and its targets. Western blot and NF-κB activity analysis suggested OSR1 inhibited NF-κB activity. Double inhibition of OSR1 and NF-κB significantly inhibited TSCC cell migration and invasion. These findings suggested OSR1 inhibited TSCC cell migration and invasion through inhibiting NF-κB pathway.

Clinical analysis of second primary gingival squamous cell carcinoma after radiotherapy

INTRODUCTION

Clinically, we have observed that some oral cancer patients have a history of radiotherapy for head and neck cancer; we have named this condition radiotherapy-associated cancer (RAC). Gingival cancer, which is usually juxtaposed with other oral cancer subtypes, is seldom reported individually, and there are few reports on the association between the incidence of oral cancer and history of radiation therapy. Therefore, this study aimed to elucidate the clinicopathological features and prognosis of second primary gingival squamous cell carcinoma after head and neck radiotherapy.

MATERIALS AND METHODS

The data collected included 450 patients diagnosed with gingival squamous cell carcinoma from 1964 to 2012 at Sun Yat-sen University Cancer, among whom 52 patients had a history of radiotherapy for head and neck cancer. We retrospectively analysed the differences in the clinicopathological characteristics and prognosis between sporadic gingival squamous cell carcinoma and radiation-associated gingival carcinoma, with an emphasis on gingival carcinoma.

RESULTS

Sporadic gingival squamous cell carcinoma is less likely to have more advanced T stage, and the second primary tumour is more likely to be located in the molar area of the maxillary gingiva than in the mandibular gingiva (75.6% vs 24.4%, P < 0.05). The 5-year overall survival of patients with second primary gingival carcinoma was influenced by age distribution, T classification, N classification, clinical TNM stage, histological grade and radiation history in head and neck. Mandibular gingival carcinoma was more likely to have an increased neck lymph node metastasis than maxillary gingival carcinoma (P = 0.001), but there was no significant difference in 5-year overall survival between these two groups (P = 0.828). The main therapy for gingiva carcinoma is surgery or comprehensive treatment based on surgery.

CONCLUSIONS

Second primary gingival squamous cell carcinoma after radiotherapy demonstrated particular clinicopathologic features, such as prominent sites and TNM stage; and there was statistically significant difference in 5-year overall survival and prognosis between second primary gingival carcinoma after radiotherapy and sporadic gingival carcinoma.

Supercapacitor with high cycling stability through electrochemical deposition of metal–organic frameworks/polypyrrole positive electrode

Through electrochemical deposition, a novel positive electrode comprising ZIF-67 and polypyrrole, showing ultrahigh cycling stability (100.7%, 40 000 cycles), was fabricated.

Radiation exposure, young age, and female gender are associated with high prevalence of RET/PTC1 and RET/PTC3 in papillary thyroid cancer: a meta-analysis

Background

RET/PTC rearrangements have been identified as a specific genetic event in papillary thyroid cancer (PTC). We conducted this meta-analysis to identify an enriched population who were more likely to occur RET/PTC fusion genes.

Methods

All relevant studies in the PubMed, Web of Science, and Embase databases were searched up to June 2015. The studies found were screened according to our inclusion and exclusion criteria. All analyses were performed using STATA software.

Results

Eventually, 38 eligible studies comprising 2395 participants were included. Overall analysis indicated that radiation exposure contributed to increased RET/PTC risk (OR = 2.82; 95%CI: 1.38–5.78, P = 0.005). Stratified analysis according to RET/PTC subtype and geographical area showed that this association was restricted to the RET/PTC3 subtype (OR = 8.30, 95%CI: 4.32–15.96, P < 0.001) in the Western population. In addition, age < 18 years, i.e., young age, was associated with higher prevalence of RET/PTC3 (OR = 2.03, 95%CI: 1.14–3.62, P = 0.017), especially in the radiation-exposure subpopulation (OR = 2.35, 95%CI: 1.01–5.49, P = 0.048). The association between female gender and RET/PTC1 risk was more significant in the PTC patients without radiation exposure (OR = 1.69, 95%CI: 1.04–2.74, P = 0.034).

Conclusion

Both radiation exposure and young age are associated with increased risk of RET/PTC3 and that female gender is associated with higher prevalence of RET/PTC1 in the subpopulation without radiation exposure. The RET/PTC status in combination with radiation exposure, age, and sex should be considered in the differential diagnosis of suspicious PTC.

Associations between RET tagSNPs and their haplotypes and susceptibility, clinical severity, and thyroid function in patients with differentiated thyroid cancer

BACKGROUND

It is unclear whether common genetic variants of the RET proto-oncogene contribute to disease susceptibility, clinical severity, and thyroid function in differentiated thyroid cancer (DTC).

METHODS

A total of 300 DTC patients and 252 healthy controls were enrolled in this study. Seven RET tagging single nucleotide polymorphisms were genotyped using the KASPar platform.

RESULTS

Subgroup analysis showed that concomitant thyroid benign diseases were less likely to occur in DTC subjects with the rs1799939 AG or AG plus AA genotypes (odds ratio (OR) = 1.93 and 1.88, P = 0.009 and 0.011, respectively). A rare haplotype, CGGATAA, was associated statistically with a reduced risk of DTC (OR = 0.18, P = 0.001). Concerning the aggressive features of DTC, higher level of N stage was more likely to occur in subjects carrying the wild-type genotypes at rs1800860 site (for dominant model: OR = 0.48, P = 0.008). Another rare haplotype, CAAGCGT, conferred increased risk for the occurrence of distant metastasis (OR = 7.57, P = 0.009). Notably, higher thyroid stimulating hormone levels and lower parathyroid hormone levels were found in patients with rs2075912, rs2565200, and rs2742240 heterozygotes and rare homozygotes; similar results were observed between PTH levels and rs1800858.

CONCLUSION

This study provided useful information on RET variants that should be subjected to further study.

Downregulated expression of TSHR is associated with distant metastasis in thyroid cancer

In differentiated thyroid cancer (DTC), the association between thyroid-stimulating hormone receptor (TSHR) and metastasis, and the underlying molecular mechanisms remain unclear. The role of TSHR in the epithelial-mesenchymal transition (EMT) has not yet been reported, to the best of our knowledge. In the present study, the role of TSHR in the distant metastasis of DTC was investigated. TSHR was significantly downregulated in well-differentiated thyroid cancer cells and tissues, and a lack of TSHR promoted thyroid cancer cell invasion and metastasis by inhibiting the EMT of thyroid cancer cells. In addition, the prognostic value of TSHR in thyroid cancer was analyzed. Immunohistochemical analysis of 172 DTC tissues revealed that a lack of expression of TSHR was associated with distant metastasis and a poor survival rate. Multivariate analyses demonstrated that TSHR expression was a significant prognostic factor for distant metastasis and survival time. The results from the present study demonstrated that TSHR inhibits metastasis through regulating EMT in vitro, and that a lack of expression of TSHR is a significant independent factor affecting distant metastasis and poor prognosis in DTC.

Toxicity evaluation of graphene oxide on cysts and three larval stages of Artemia salina

Using Artemia salina as an experimental model, the potential risks of graphene oxide (GO) to marine ecosystems were investigated. Hatchability of capsulated and decapsulated cysts, mortality of instar I, II and III larvae, and a number of morphological, ethological and physiological parameters were selected as end-points for toxicity assessment. Our results show that GO significantly decreased (p<0.01) the hatchability of capsulated and decapsulated cysts following exposure to 400 and 600mg/L for 36h. There was a concentration-dependent increase in mortality and decrease in swimming speed of larvae, and instar II larvae showed a greater sensitivity compared with instar I and instar III larvae. The LC₅₀ values of instar II and III were 368.18 and 387.68mg/L, respectively (not calculable for instar I). The EC₅₀ values for swimming speed alteration of instar I, II and III were 415.13, 273.50 and 289.05mg/L, respectively. Moreover, body lengths and individual dry weight of larvae (instar I, II and III) also decreased in dose-dependent manners. GO attached onto the surface of cysts and larvae, resulting in irreversible damage to the larval body surface. All of malondialdehyde content, total antioxidant capacity, reactive oxygen species and superoxide dismutase activity of A. salina larvae substantially increased in dose-dependent manners after exposure to GO suspensions, indicating that toxic effects were due to oxidative damages. However, for the activities of catalase, glutathione peroxidase and glutathione S-transferase, GO induced different effects on the larvae. Finally, the uptake result indicated that GO was ingested and concentrated in the gut, and was visible within the primary body cavity and yolk.

[RET/PTC rearrangement affects multifocal formation of papillary thyroid carcinoma]

Objective:RET/PTC gene rearrangement can lead to aberrant activation of tyrosine kinase receptors, which is a common mutation in papillary thyroid carcinoma (PTC). This study focuses on the association of RET/PTC rearrangements with PTC clinical factors. Methods: From January 2011 to December 2013, a total of 114 patients with PTC were enrolled in this study. Clinicopathological parameters, lifestyle, and thyroid hormone levels were collected. RET/PTC rearrangements were detected by TaqMan PCR and verified by Sanger sequencing.Data were analyzed with SPSS software, including chi-square test, Fisher's exact test, Mann-Whitney U test, Student's t-test, and Logistic regression. Results:RET/PTC rearrangements were not found in all paracancerous normal thyroid tissues, and were detected in 23.68% (27/114) of PTC. Further analysis revealed no correlation between RET/PTC rearrangement and thyroid function, clinicopathologic parameters, and lifestyle in the total PTC group or in the subgroup of patients with concomitant diseases (including Hashimoto's thyroiditis and nodular goiter). But in the subgroup of PTC without concomitant disease, RET/PTC rearrangement was associated with tumor multifocal (P=0.018), and RET/PTC-positive PTC patients had an increased risk of tumor multifocal (OR=5.57, 95% CI 1.39-22.33). It was also found that RET/PTC rearrangement was associated with an abnormal increase in TSH level of one month after surgery (P= 0.037). Conclusion: Nodular goiter and Hashimoto 's thyroiditis may be a confounding factor in PTC. RET/PTC rearrangement may play an important role in the occurrence of thyroid carcinoma multifocal after exclusion of this confounding factor.

Oxidative Polyoxometalates Modified Graphitic Carbon Nitride for Visible-Light CO2 Reduction

Developing a photocatalysis system for converting CO₂ to valuable fuels or chemicals is a promising strategy to address global warming and fossil fuel consumption. Exploring photocatalysts with high-performance and low-cost has been two ultimate goals toward photoreduction of CO₂. Herein, noble-metal-free polyoxometalates (Co4) with oxidative ability was first introduced into g-C₃N₄ resulted in inexpensive hybrid materials (Co4@g-C₃N₄) with staggered band alignment. The staggered composited materials show a higher activity of CO₂ reduction than bare g-C₃N₄. An optimized Co4@g-C₃N₄ hybrid sample exhibited a high yield (107 μmol g^-1 h^-1) under visible-light irradiation (λ ≥ 420 nm), meanwhile maintaining high selectivity for CO production (94%). After 10 h of irradiation, the production of CO reached 896 μmol g^-1. Mechanistic studies revealed the introduction of Co4 not only facilitate the charge transfer of g-C₃N₄ but greatly increased the surface catalytic oxidative ability. This work creatively combined g-C₃N₄ with oxidative polyoxometalates which provide novel insights into the design of low-cost photocatalytic materials for CO₂ reduction.

Strong Enhancement of Photoelectric Conversion Efficiency of Co-hybridized Polymer Solar Cell by Silver Nanoplates and Core-Shell Nanoparticles

A new way was meticulously designed to utilize the localized surface plasmon resonance (LSPR) effect and the light scattering effect of silver nanoplate (Ag-nPl) and core-shell Ag@SiO₂ nanoparticles (Ag@SiO₂-NPs) to enhance the photovoltaic performances of polymer solar cells (PSCs). To prevent direct contact between silver nanoparticles (Ag-NPs) and photoactive materials which will cause electrons quenching, bare Ag-nPl were spin-coated on indium tin oxide and silica capsulated Ag-NPs were incorporated to a PBDTTT-C-T:PC₇₁BM active layer. As a result, the devices incorporated with Ag-nPl and Ag@SiO₂-NPs showed great enhancements. With the dual effects of Ag-nPl and Ag@SiO₂-NPs in devices, all wavelength sensitization in the visible range was realized; therefore, the power conversion efficiency (PCE) of PSCs showed a great enhancement of 14.0% to 8.46%, with an increased short-circuit current density of 17.23 mA·cm^-2. The improved photovoltaic performances of the devices were ascribed to the LSPR effect and the light scattering effect of metallic nanoparticles. Apart from optical effects, the charge collection efficiency of PSCs was improved after the incorporation of Ag-nPl.