Synthesis of Fused-Ring Derivatives Containing Bifluorenylidene Units via Pd-Catalyzed Tandem Multistep Suzuki Coupling/Heck Cyclization Reaction.

A series of bifluorenylidene derivatives has been facilely synthesized via a palladium-catalyzed tandem multistep Suzuki cross-coupling and Heck cyclization in one pot. The tandem reaction involves two sequential Suzuki couplings and a subsequent Heck cyclization. The target products are obtained in good yields up to 94%. Even in an extended conjugated substrate, the anticipated products can be prepared.

The surface reconstruction induced enhancement of the oxygen evolution reaction on α-SnWO4 (010) based on a density functional theory study.

The coordination environment of photocatalytic active sites is determined by the type of surface termination on an α-SnWO4 semiconductor. However, the stability of these surface terminations has not been thoroughly explored. In this work, the stability of the α-SnWO4(010) surface termination was studied using a thermodynamic analysis based on density functional theory (DFT). Under appropriate thermodynamic equilibrium conditions, it is possible to stabilize the O-W, O-Sn, R-OOSn and ST3 terminations of the α-SnWO4(010) surface. The electronic structures of these three potential stable surface terminations are also calculated using a Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional to determine the conceivable bandgap values. It is found that there are numerous surface states in the bandgap of these terminations. This is due to the evident reconstruction of these terminations after geometry optimization. In addition, work functions are substantially different for possible surface terminations. The results suggest that Z-scheme heterostructures based on SnWO4 can be regulated by securing the thermodynamically favorable surface terminations under suitable physical/chemical conditions. At last, O-Sn termination exhibits a low overpotential value of 0.51 V, showing remarkable oxygen evolution reaction (OER) performance among all stable surface terminations considered in this work. Our study may help explore the intrinsic surface properties of SnWO4, which will be a viable strategy for developing SnWO4-based photocatalysts.

Partial locking in phase-oscillator populations with heterogenous coupling.

We consider a variant of the mean-field model of coupled phase oscillators with uniform distribution of natural frequencies. By establishing correlations between the quenched disorder of intrinsic frequencies and coupling strength with both in- and out-coupling heterogeneities, we reveal a generic criterion for the onset of partial locking that takes place in a domain with the coexistence of phase-locked oscillators and drifters. The critical points manifesting the instability of the stationary states are obtained analytically. In particular, the bifurcation mechanism of the equilibrium states is uncovered by the use of frequency-dependent version of the Ott-Antonsen reduction consistently with the analysis based on the self-consistent approach. We demonstrate that both the manner of coupling heterogeneity and correlation exponent have influence on the emergent patterns of partial locking. Our research could find applicability in better understanding the phase transitions and related collective phenomena involving synchronization control in networked systems.

An Organic-Inorganic Hybrid Electrolyte as a Cathode Interlayer for Efficient Organic Solar Cells.

An organic-inorganic hybrid electrolyte based on a cyclic Ti-oxo cluster as the inorganic core and naphthalene-based organic ammonium bromide salts as the electrolyte was developed with easy synthesis and low cost. The new hybrid electrolyte exhibits excellent solubility in methanol, aligned work function, good conductivity, and amorphous state in thin film, enabling its successful application as a cathode interlayer in organic solar cells with a high power conversion efficiency of 17.19 %. This work demonstrates that the hybrid electrolytes are a new kind of semiconductor, exhibiting promising applications in organic electronics.

Design of an InP/ZnO core-shell nanocone array solar cell with efficient broadband light absorption enhancement.

We design a standing semiconductor-dielectric core-shell nanocone array (CSNCA) that can not only concentrate the incident light into the structure, but also confine most of the concentrated light to the semiconductor (indium phosphide) core region, which remarkably enhances the light absorption of the more material-saving semiconductor core. We find guided resonance features along the radial and FP-resonant features along the axial direction by analyzing the electric field patterns at the absorption spectrum peaks. The CSNCA can support multiple higher-order HE modes, in comparison to the bare nanocone array (BNCA). Results based on detailed balance analysis demonstrate that the core-shell design gives rise to higher short-circuit current and open-circuit voltage, and thus higher power conversion efficiency. Detailed research is focused on the 1 µm high CSNCAs, and a remarkable power conversion efficiency enhancement (42.2%) is gained compared with the BNCAs.

Endoscopic Endonasal Approach for Resection of Tuberculum Sellae Meningioma: A Promising Surgical Approach.

BACKGROUND: Over the past decade, endoscopic approaches have been increasingly successful in removing various types of extra-dural lesions from the skull base. Resection of tuberculum sellae meningiomas (TSMs) is challenging. The endoscopic endonasal approach (EEA) for the removal of TSMs is currently an acceptable surgical approach in neurosurgery and, despite the surgical results, the indications and limitations of this approach remain controversial. OBJECTIVE: This paper reviews the authors' experience and outcomes with the EEA for TSM, as well as postoperative complications. METHODS: Retrospective analyses were performed on patients who underwent endoscopic surgical resection of TSMs involving the suprasellar region between January 2018 and March 2019. RESULTS: Three patients underwent resection of their TSM by the EEA. Tumors in the suprasellar region were completely resected. Patients recovered normally with uneventful postoperative outcomes and were followed-up for at least six months after surgery with no neurological deficits noted. CONCLUSIONS: The EEA for resection of TSMs is feasible, safe, and effective, with fewer complications and lower mortality than other surgical methods. This a promising surgical approach.

Broadband light absorption enhancement in randomly rotated elliptical nanohole arrays for photovoltaic application.

Semiconducting nanohole arrays have been considered as a promising candidate for high-efficiency solar cells. In this paper, the optical absorption property of randomly rotated elliptical nanohole arrays consisting of 1×1, 2×2, and 4×4 cells has been investigated. It is found that the average ultimate efficiency of the arrays increases with the increase of the size of the supercell. The 4×4 array has the highest ultimate efficiency, and the efficiency of the 4×4 array is less sensitive to the parameters of the random rotation angle than that of the 1×1 and 2×2 arrays. The comparison of absorption spectra of the three arrays shows that the number of absorption peaks of the 1×1 array is the least, but the peak is the highest and narrowest, and that of the 4×4 array is the most, but the peak is the lowest and broadest. The spatial Fourier spectroscopy analysis of the array shows that the 4×4 arrays have the most Fourier spectrum components and the largest absorption mode density. The enhancement of optical absorption of the 4×4 array is attributed to the folding of energy bands, the increase of the energy density of states caused by large supercells, and the overcoupling between incident light and Bloch resonant modes in the structure. The improved stability of the ultimate efficiency of the 4×4 arrays is because the distribution of the energy density of states of the 4×4 arrays with different random parameters tends to be the same, which leads to almost the same absorption efficiency of the different 4×4 arrays.

Crystalline Cooperativity of Donor and Acceptor Segments in Double-Cable Conjugated Polymers toward Efficient Single-Component Organic Solar Cells.

The crystalline cooperativity of the donor and acceptor segment in double-cable conjugated polymers plays an important role in the nanophase separation and photovoltaic performance in single-component organic solar cells (SCOSCs). Two double-cable conjugated polymers with the same conjugated backbone and perylene bisimide (PBI) side units were designed in which PBIs were positioned symmetrically and perpendicularly (P1) and asymmetrically and slantingly (P2) along the conjugated backbones. After thermal annealing, both conjugated backbones and PBI side units in P1 tend to form ordered nanostructures, while PBI side units in P2 dominated the crystallization and hamper the crystallization of conjugated backbones. P1 showed good crystalline cooperativity between conjugated backbones and PBI side units, resulting in improved power conversion efficiencies (PCEs) up to 3.43 % in SCOSCs, while P2 with poor crystalline cooperativity exhibited PCEs below 2.42 %.

[Role of ACE2-Ang (1-7)-Mas receptor axis in heart failure with preserved ejection fraction with hypertension].

OBJECTIVE: To investigate changes in the angiotensin converting enzyme 2 (ACE2) and angiotensin (1-7) [Ang (1-7)] and to explore the role of ACE2-Ang (1-7)-Mas receptor axis in hypertension with heart failure with preserved ejection fraction (HFPEF).
 Methods: A total of 70 patients with primary hypertension and preserved left ventricular ejection fraction (LVEF>50%) were recruited and patients were divided into a hypertension group (HBP) and a heart failure with preserved ejection fraction group (HFpEF) according to the diagnostic criteria of HFpEF. Thirty-five healthy participants were selected randomly as a control group. Enzyme linked immunosorbent assays (ELISA) method was used to detect concentration of Ang (1-7), ACE2, angiotensin II (Ang II), brain natriuretic peptide (BNP) in plasma. Male Sprague- Dawley (SD) rats was randomly divided into 2 groups: An HFpEF group (n=16) and a sham group (n=8). Rats (n=8) in the AAC group were given Ang (1-7) [0.5 mg/(kg.d), intraperitoneally] for 6 weeks, and the rest were given equal dose normal saline. Then all the rats were killed, and the hearts were taken out for hematoxylineosin (HE) staining. The protein expressions of angiotensin converting enzyme (ACE), ACE2, and Mas receptor were detected by Western blot.
 Results: The BNP and Ang II were significantly increased in the HBP group and the HFpEF group compared with the control group (P<0.01). There were not significantly different in levels of ACE2 and Ang (1-7) between the HBP group and control group (P>0.05), whereas those levels were significantly increased in the HFpEF group compared with the HBP group and control group (P<0.01). HE staining showed obvious hypertrophy of myocardial cell in the AAC group compared with the sham group. Hypertrophy of myocardial cell in the AAC+Ang (1-7) group was significantly higher than that in the AAC group. Expressions of ACE, ACE2, and Mas receptor proteins were significantly higher in the AAC group than those in the sham group (P<0.05), while the expressions of ACE2 and Mas receptor proteins in the AAC+Ang (1-7) group were significantly higher than those in the AAC group (P<0.05). There was no significant difference in the ACE protein expression between groups (P>0.05).
 Conclusion: ACE2 and Ang (1-7) are important predictive factors for the severity of heart failure and myocardial remodeling of HFpEF with hypertension; ACE2-Ang (1-7)-Mas receptor axis may play a protective role in preventing myocardial remodeling in HFpEF with hypertension.

CD44+ fibroblasts increases breast cancer cell survival and drug resistance via IGF2BP3-CD44-IGF2 signalling.

CD44, a cell adhesion protein, involves in various process in cancer such as cell survival and metastasis. Most researches on CD44 in cancer focus on cancer cells. Recently, it is found that CD44 expression is high in fibroblasts of tumour microenvironment. However, its role in communication between fibroblasts and breast cancer cells is seldom known. In this study, CD44-positive (CD44+ Fbs) and CD44-negative carcinoma-associated fibroblasts (CD44- Fbs) were isolated and cocultured with breast cancer cells for analysis of cell survival and drug resistance. We found that CD44+ Fbs promoted breast cancer cell survival and paclitaxel resistance and inhibited paclitaxel-induced apoptosis. Our further research for the molecular mechanism showed that IGF2BP3 bound to CD44 mRNA and enhanced CD44 expression, which increased IGF2 levels of fibroblasts and then stimulated breast cancer cell proliferation and drug resistance. IGF2 was found to activate Hedgehog signal pathway in breast cancer cells. In conclusion, the results illustrated that in CD44+ Fbs, binding of IGF2BP3 and CD44 promotes IGF2 expression and then accelerates breast cancer cell proliferation, survival and induced chemotherapy resistance likely by activating Hedgehog signal pathways.

Toward high performance nanoscale optoelectronic devices: super solar energy harvesting in single standing core-shell nanowire.

Single nanowire solar cells show great promise for next-generation photovoltaics and for powering nanoscale devices. Here, we present a detailed study of light absorption in a single standing semiconductor-dielectric core-shell nanowire (CSNW). We find that the CSNW structure can not only concentrate the incident light into the structure, but also confine most of the concentrated light to the semiconductor core region, which boosts remarkably the light absorption cross-section of the semiconductor core. The CSNW can support multiple higher-order HE modes, as well as Fabry-Pérot (F-P) resonance, compared to the bare nanowire (BNW). Overlapping of the adjacent higher-order HE modes results in broadband light absorption enhancement in the solar radiation spectrum. Results based on detailed balance analysis demonstrate that the super light concentration of the single CSNW gives rise to higher short-circuit current and open-circuit voltage, and thus higher apparent power conversion efficiency (3644.2%), which goes far beyond that of the BNW and the Shockley-Queisser limit that restricts the performance of a planar counterparts. Our study shows that the single CSNW can be a promising platform for construction of high performance nanoscale photodetectors, nanoelectronic power sources, super miniature cells, and diverse integrated nanosystems.

A Novel Water-Soluble Fluorescence Probe with Wash-Free Cellular Imaging Capacity Based on AIE Characteristics.

A potential real-time imaging water-soluble fluorescent polymer (P3) is facilely prepared via one-pot method. For P3, tetraphenylethene unit serves as the fluorescent unit, poly(acryloyl ethylene diamine) (a kind of polyelectrolyte) with specific degree of polymerization acts as water-soluble part. 1 H-NMR, gel permeation chromatography (GPC), UV-vis spectroscopy, photoluminescence (PL), and confocal laser scanning microscopy are undertaken to characterize the structure and property of P3. The results of wash-free cellular imaging show that the signal-to-noise ratio is high as the concentration of P3 is 50 µg mL-1 . In addition, the pH-responsive and Cd2+ -responsive are also investigated in this paper. The results coming from pH-responsive show that P3 solution displays significant fluorescence under near neutral. And the result from the cellular imaging shows that intracellular fluorescence intensity enhances with the augment of concentration of Cd2+ , which reveals that P3 can give a hint to resolve the dilemma of traditional fluorescent dyes used as living cellular fluorescent probe.

Enhanced light absorption in perpendicular elliptical silicon nanocone array for solar cells.

Silicon nanowire-based arrays have demonstrated superior light trapping properties and great potential for next-generation photovoltaics. In this paper, we propose a perpendicular elliptical nanocone (PENC) array solar cell, which introduces an asymmetry in the direction parallel to the array surface in addition to the asymmetry in the direction normal to the array surface, which has been implemented in the circular nanocone (CNC) array. The PENC array displays more and higher resonant absorption peaks in the long wavelength compared with the CNC array. The newly exhibiting absorption peaks are found to be derived from periodical Bloch modes by the band-folding of the PENC array and cavity modes introduced by the asymmetry of the elliptical nanocone. The ultimate efficiency of the optimal PENC array is 24.3%, which is 17.4% higher than that of the optimal CNC one with the same nanocone height and 59.1% higher than that of the flat counterpart coated with a 70 nm zinc-oxide antireflection film. When the nanocone height is between 0.3 and 5.0 µm and the incident angle is between 0° and 80°, the PENC array demonstrates better light trapping property compared with the CNC ones.

Accuracy of pedicle screw insertion in posterior scoliosis surgery: a comparison between intraoperative navigation and preoperative navigation techniques.

PURPOSE: This study was conducted to compare the efficacy and accuracy of intraoperative navigation (O-arm or Arcadis navigation) and preoperative CT-based navigation in adolescent idiopathic scoliosis (AIS) surgery. METHODS: Sixty-seven patients with scoliosis were grouped according to the method of navigation used in their fixation surgeries. A total of 492 pedicle screws were implanted in 27 patients using intraoperative navigation, and 626 screws were implanted in 40 patients using preoperative navigation. We analyzed the postoperative CT images for pedicle violations using the Gertzbein classification. RESULTS: There was no statistical difference in the accuracy of pedicle screw placement between two groups. However, in the apical region (the apex ± 2 vertebrae), the accuracy of safe pedicle screw placement (grades 0, 1) was significantly higher in the intraoperative navigation group than in the preoperative navigation group (94.8 vs 89.2%, respectively; P = 0.035). Intraoperative navigation significantly diminished medial perforation compared to preoperative navigation (P = 0.027), and the number of screws per vertebra that could be placed in the apical region was significantly higher in intraoperative navigation group (P < 0.001). In addition, the time required for the registration procedure and insertion of one pedicle screw was 11.3 ± 2.1 min in the preoperative group, but significantly decreased to 5.1 ± 1.1 min in the intraoperative group (P < 0.001). CONCLUSIONS: Both preoperative CT-based and intraoperative navigation systems provide sufficient accuracy and safety in pedicle screw insertion for AIS surgery. Intraoperative navigation systems facilitate pedicle screw insertion in the apical region and reduce registration time during AIS surgery which improves the efficacy and accuracy of pedicle screw insertion.

Synthesis, characterization and fluorescent properties of water-soluble glycopolymer bearing curcumin pendant residues.

Curcumin is a potential natural anticancer drug with low oral bioavailability because of poor water solubility. The aqueous solubility of curcumin is enhanced by means of modification with the carbohydrate units. Polymerization of the curcumin-containing monomer with carbohydrate-containing monomer gives the water-soluble glycopolymer bearing curcumin pendant residues. The obtained copolymers (P1 and P2) having desirable water solubility were well-characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), UV-Vis absorption spectroscopy, and photoluminescence spectroscopy. The copolymer P2 with a molar ratio of 1:6 (curcumin/carbohydrate) calculated from the proton NMR results exhibits a similar anticancer activity compared to original curcumin, which may serve as a potential chemotherapeutic agent in the field of anticancer medicine.

Efficient broadband light absorption in elliptical nanohole arrays for photovoltaic application.

We propose a perpendicular elliptical silicon nanohole (PE-SiNH) array for light absorption in thin film silicon solar cells. Our analysis shows that this architecture is capable of increasing the absorption of a thin film silicon solar cell by 11.3% in comparison to that of the optimal circular SiNH array. The process of breaking the mirror symmetries is responsible for the increase of the coupled modes. The PE-SiNH structures show additional near-zero spatial Fourier components compared with the circular SiNH structure, which helps to couple more incident light into slow Bloch modes. The mode interaction between adjacent elliptical nanoholes is in favor of the coupling of the incident light into channeling modes and, therefore, enhances light absorption in the short wavelength region.

[A case of PET-CT imaging for primary hyperparathyroidism].

OBJECTIVE: To explore the 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (¹8F-FDG) positron emission tomography/computed tomography (PET-CT) manifestations and functions in patients with primary hyperparathyroidism (pHPT). 
 METHOD: The diagnosis of 1 case of double parathyroid adenomas secondary to pPTH was reported and the related literature was reviewed.
 RESULTS: PET-CT showed two nodus shadow with slightly lower density compared with muscle, clear boundary and uniform density. Simultaneously, images also showed multiple enhanced FDG uptake of bone lesions in skeletal system. The maximum standard uptake values for ¹8F-FDG in the destructive bone lesions were more than 10. 
 CONCLUSION: ¹8F-FDG PET-CT is a well-established imaging technique for the diagnosis in pHPT. It not only can clearly visualize systemic lesions and accurately assess the extent of the disease, but also can accurately localize parathyroid adenoma. After resection of parathyroid adenoma, FDG PET-CT imaging can be useful to see the response to treatment and osteoblastic changes in brown tumor.

Broadband absorption enhancement in elliptical silicon nanowire arrays for photovoltaic applications.

Semiconducting nanowire arrays have emerged as a promising route toward achieving high efficiencies in solar cells. Here we propose a perpendicular elliptical silicon nanowire (PEE-SiNW) array for broadband light absorption in thin film silicon solar cells. Simulation results reveal that light absorption enhancement is originated from the split of the principal modes as well as the excitation of high order modes caused by the asymmetry of the elliptical nanowires and the enhanced mode coupling between adjacent elliptical nanowires attained by the appropriate arrangement of nanowires. An ultimate efficiency of 29.1% is achieved for the optimal PEE-SiNW array, which is 16.4% higher than that of the circular SiNW array with the same fill fraction.

Identification of a subtype-specific ENC1 gene related to invasiveness in human pituitary null cell adenoma and oncocytomas.

Non-functioning pituitary adenomas (NFPAs) may be locally invasive. Surgery is a treatment option, but unlike the case for functional pituitary adenomas, there are almost no drug treatments available for NFPAs. Markers of invasiveness are needed to guide therapeutic decision-making and identify potential adjuvant drugs. Owing to the highly heterogeneous nature of NFPAs, little is known regarding the subtype-specific gene expression profiles associated with invasiveness. To identify important biomarkers of invasiveness, we selected 23 null cell adenomas and 20 oncocytomas. These tumors were classified as invasive or non-invasive adenomas based on magnetic resonance imaging, pathology slides and surgical findings. Firstly, we observed that there were significant differences in expression between invasive (n = 3) and non-invasive (n = 4) adenomas by gene expression microarray. A total of 1,188 genes were differentially expressed in the invasive and non-invasive adenomas. Among these 1,188 genes, 578 were upregulated and 610 were downregulated in invasive adenomas. Secondly, the expression of ENC1, which displayed the significant alterations, was further confirmed by qRT-PCR and Western blot analysis in all 43 tumor samples and three normal pituitary glands. Low levels of ENC1 were found in tumor samples, while high levels were detected in normal pituitary glands. Interestingly, the ENC1 expression level was low in invasive null cell adenomas compared with non-invasive adenomas, but this relationship was not observed in invasive oncocytomas. Immunohistochemistry also demonstrated that the staining of ENC1 was different between invasive and non-invasive null cell adenomas. In addition, bioinformatics studies, including gene ontology and protein interaction analyses, were also performed to better understand the critical role of ENC1 in the development and progression of null cell adenomas and oncocytomas. Consequently, ENC1 may be an important biomarker for null cell adenomas and oncocytomas, and it is specific to invasive null cell adenomas.

Low levels of PRB3 mRNA are associated with dopamine-agonist resistance and tumor recurrence in prolactinomas.

Prolactinomas, or prolactin-secreting adenomas, constitute the most common type of hyperfunctioning pituitary adenoma. Dopamine agonists are used as first-line medication for prolactinomas, but the tumors are resistant to the therapy in 5-18 % of patients. To explore potential mechanisms of resistance to bromocriptine (a dopamine agonist), we analyzed six responsive prolactinomas and six resistant prolactinomas by whole-exome sequencing. We identified ten genes with sequence variants that were differentially found in the two groups of tumors. The expression of these genes was then quantified by real-time reverse-transcription PCR (RT-qPCR) in the 12 prolactinomas and in six normal pituitary glands. The mRNA levels of one of the genes, PRB3, were about fourfold lower in resistant prolactinomas than in the responsive tumors (p = 0.02). Furthermore, low PRB3 expression was also associated with tumor recurrence. Our results suggest that low levels of PRB3 mRNA may have a role in dopamine-agonist resistance and tumor recurrence of prolactinomas.