Solution-Processed Transparent Electrodes for Emerging Thin-Film Solar Cells.

Solution-processed solar cells are appealing because of the low manufacturing cost, the good compatibility with flexible substrates, and the ease of large-scale fabrication. Whereas solution-processable active materials have been widely adopted for the fabrication of organic, dye-sensitized, and perovskite solar cells, vacuum-deposited transparent conducting oxides (TCOs) such as indium tin oxide, fluorine-doped tin oxide, and aluminum-doped tin oxide are still the most frequently used transparent electrodes (TEs) for solar cells. These TCOs not only significantly increase the manufacturing cost of the device, but also are too brittle for future flexible and wearable applications. Therefore, developing solution-processed TEs for solar cells is of great interest. This paper provides a detailed discussion on the recent development of solution-processed TEs, including the chemical synthesis of the electrode materials, the solution-based technologies for the electrode fabrication, the optical and electrical properties of the solution-processed TEs, and their applications on solar cells.

A New Tetradentate Mixed Aza-Thioether Macrocycle and Its Complexation Behavior towards Fe(II), Ni(II) and Cu(II) Ions.

A new tetradentate mixed aza-thioether macrocyclic ligand 2,6-dithia[7](2,9)-1,10-phenanthrolinophane ([13]ane(phenN2)S2) was successfully synthesized. Reacting metal precursors [Fe(CH3CN)2(OTf)2], Ni(ClO4)2·6H2O, and Cu(ClO4)2·6H2O with one equivalent of [13]ane(phenN2)S2 afforded [Fe([13]ane(phenN2)S2)(OTf)2] (1), [Ni([13]ane(phenN2)S2)](ClO4)2 (2(ClO4)2), and [Cu([13]ane(phenN2)S2)(OH2)](ClO4)2 (3(ClO4)2), respectively. The structures of [13]ane(phenN2)S2 and all of its metal complexes were investigated by X-ray crystallography. The [13]ane(phenN2)S2 was found to behave as a tetradentate ligand via its donor atoms N and S.

Freestanding Lamellar Porous Carbon Stacks for Low-Temperature-Foldable Supercapacitors.

High-performance supercapacitors (SCs) are important energy storage components for emerging wearable electronics. Rendering low-temperature foldability to SCs is critically important when wearable devices are used in a cold environment. However, currently reported foldable SCs do not have a stable electrochemical performance at subzero temperatures, while those that are performing are not foldable. Herein, a freestanding pure-carbon-based porous electrode, namely, lamellar porous carbon stack (LPCS), is reported, which enables stable low-temperature-foldable SCs. The LPCS, which is fabricated with a simple vacuum filtration of a mixture of carbon fibers (CFs), holey reduced graphene oxides (HRGOs), and carbon nanotubes (CNTs), possesses a lamellar stacking of porous carbon thin sheets, in which the CFs act as the skeleton and the HRGOs and CNTs act as binders. The unique structure leads to excellent compression resilience, high foldability, and high electronic and ionic conductivity. SCs made with the LPCS electrodes and ionic liquid electrolyte show a high energy density (2.1 mWh cm-2 at 2 mA cm-2 ), low-temperature long lifetime (95% capacity after 10 000 cycles at -30 °C), and excellent low-temperature foldability (86% capacity after 1000 folding cycles at -30 °C).

Phosphonium-Ring-Fused Bicyclic Metallafuran Complexes of Ruthenium and Osmium.

Metallafuran complexes with a fused five-membered phosphonium ring were synthesized from reactions between terminal ynones HC≡C(C=O)R and cis-[Ru/Os(dppm)2 Cl2 ] (dppm=1,1-bis(diphenylphosphino)methane). A metal-vinylidene-involving pathway was found to be an energetically feasible formation mechanism for these complexes. These phosphonium-containing metallafurans, like many phosphonium-functionalized drugs, have the ability to induce mitochondrial dysfunction. They also exhibit stronger cytotoxicity against several human cancer cell lines in comparison with their metal precursors and the classic anticancer drug cisplatin. Overall, this work provides structural and mechanistic insights for the rational design of functional metallacycles via activation of alkynes by RuII and OsII centers.

Metalated Chromene and Chromone Complexes: pH Switchable Metal-Carbon Bonding Interaction, Photo-triggerable Chromone Delivery Application, and Antioxidative Activity.

The two families of RuII -chromene and -chromone complexes isolated in this work represent the first examples of metalated chromene and chromone complexes synthesized through transition-metal-mediated cyclization of phenol-tethered ynone. These unprecedented metalated heterocyclic compounds exhibit remarkable features, such as pH-switchable metal-carbon bonding interactions, photo-triggerable release of organic chromone upon visible-light irradiation, and superior antioxidative property to their organic analogue (1,4-benzopyrone). These findings not only offer mechanistic insights into metal-induced activation of functionalized alkynes, but also add a new dimension to rational design of antioxidants and photo-responsive drug delivery systems.

Artificial cilia for soft and stable surface covalent immobilization of bone morphogenetic protein-2.

Preservation of growth factor sensitivity and bioactivity (e.g., bone morphogenetic protein-2 (BMP-2)) post-immobilization to tissue engineering scaffolds remains a great challenge. Here, we develop a stable and soft surface modification strategy to address this issue. BMP-2 (a model growth factor) is covalently immobilized onto homogeneous poly (glycidyl methacrylate) (PGMA) polymer brushes which are grafted onto substrate surfaces (Au, quartz glass, silica wafer, or common biomaterials) via surface-initiated atom transfer radical polymerization. This surface modification method multiplies the functionalized interfacial area; it is simple, fast, gentle, and has little effect on the loaded protein owing to the cilia motility. The immobilized BMP-2 (i-BMP-2) on the surface of homogeneous PGMA polymer brushes exhibits excellent bioactivity (⁓87% bioactivity of free BMP-2 in vitro and 20%-50% higher than scaffolds with free BMP-2 in vivo), with conformation and secondary structure well-preserved after covalent immobilization and ethanol sterilization. Moreover, the osteogenic activity of i-BMP-2 on the nanoline pattern (PGMA-poly (N-isopropylacrylamide)) shows ⁓110% bioactivity of free BMP-2. This is superior compared to conventional protein covalent immobilization strategies in terms of both bioactivity preservation and therapeutic efficacy. PGMA polymer brushes can be used to modify surfaces of different tissue-engineered scaffolds, which facilitates in situ immobilization of growth factors, and accelerates repair of a wide range of tissue types.

Electrochemical Replication and Transfer for Low-Cost, Sub-100 nm Patterning of Materials on Flexible Substrates.

The fabrication of high-resolution patterns on flexible substrates is an essential step in the development of flexible electronics. However, the patterning process on flexible substrates often requires expensive equipment and tedious lithographic processing. Here, a bottom-up patterning technique, termed electrochemical replication and transfer (ERT) is reported, which fabricates multiscale patterns of a wide variety of materials by selective electrodeposition of target materials on a predefined template, and subsequent transfer of the electrodeposited materials to a flexible substrate, while leaving the undamaged template for reuse for over 100 times. The additive and parallel patterning attribute of ERT allows the fabrication of multiscale patterns with resolutions spanning from sub-100 nm to many centimeters simultaneously, which overcomes the trade-off between resolution and throughput of conventional patterning techniques. ERT is suitable for fabricating a wide variety of materials including metals, semiconductors, metal oxides, and polymers into arbitrary shapes on flexible substrates at a very low cost.

Clinical Audit on Chronic Obstructive Pulmonary Disease (COPD) Management in Primary Care: A Quality Improvement Project from Hong Kong.

Objective: To enhance the quality of COPD management in primary care via a two-phase clinical audit in Hong Kong. Methods: COPD patients aged 40 or above and had attended any of the 73 public primary care clinics under the Hospital Authority of Hong Kong (HAHK) for follow up (FU) during the audit period were included. Performance of six evidence-based audit criteria on COPD care was reviewed in phase 1 from 1st April 2017 to 31st March 2018. Service gaps were identified and a series of quality improvement strategies were executed in the one-year implementation phase. The outcome of the service enhancement was assessed in phase 2 from 1st April 2019 to 31st March 2020. Student's t-test and the chi-square test were used to examine the statistically significant differences between the two phases. Results: Totally 10,385 COPD cases were identified in phase 1, the majority were male (87.7%) and the mean age was 75.3±9.9 years. Among the 3102 active smokers, 1788 (57.6%) were referred to receive the smoking cessation counselling and 1578 (50.9%) actually attended it. A total of 4866 cases (46.9%) received seasonal influenza vaccine (SIV) and 4227 cases (40.7%) received pneumococcal vaccine (PCV). A total of 1983 patients (19.1%) had spirometry test done before and 1327 patients (12.8%) had history of hospital admission due to acute exacerbation of COPD (AECOPD). After the proactive implementation phase, performance on all criteria was significantly improved in phase 2, with a marked increase in the SIV and PCV uptake rate and spirometry performance rate. Most importantly, a significant reduction in AECOPD rate leading to hospital admission had been achieved (9.6%, P<0.00001). Conclusion: COPD care at all public primary care clinics of HAHK had been significantly improved for all audit criteria via the systematic team approach, which, in turn, reduced the hospital admission rate and helped relieve the burden of the health care system.

Iron(ii)-induced cycloisomerization of alkynes via"non-vinylidene" pathways for iron(ii)-indolizine and -indolizinone complexes.

Reactions between pyridine-functionalized alkynes and an Fe(ii) precursor supported by 2,5,8-trithia[9](2,9)-1,10-phenanthrolinophane afforded the first Fe(ii)-indolizine and -indolizinone complexes. Structural analysis and theoretical calculations revealed the existence of unconventional "non-vinylidene" pathways and challenged the generality of vinylidene intermediacy in Fe(ii)-induced alkyne transformations.

Ruthenium-indolizinone complexes as a new class of metalated heterocyclic compounds: insight into unconventional alkyne activation pathways, revelation of unexpected electronic properties and exploration of medicinal application.

The two series of ruthenium-indolizinone complexes prepared by Ru-mediated cyclization of pyridine-tethered alkynes represent the first examples of metalated indolizinone complexes. Joint experimental-theoretical investigation suggests an unconventional 5-endo-dig cyclization pathway as their formation mechanism. They also exhibit moderate cytotoxicity against several human cancer cell lines.

Luminescent Iridium(III) Complexes Supported by N-Heterocyclic Carbene-based C

Iridium(III) hydrido complexes containing N-heterocyclic carbene (NHC)-based pincer ligand 1,3-bis(1-butylimidazolin-2-ylidene)phenyl anion (C(1)^C^C(1)) or 1,3-bis(3-butylbenzimidazolin-2-ylidene)phenyl anion (C(2)^C^C(2)) and aromatic diimine (2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), 4,4'-dimethyl-2,2'-bipyridine (Me2bpy), or dipyrido-[3,2-f:2',3'-h]-quinoxaline (dpq)) in the form of [Ir(C^C^C)(N^N)(H)](+) have been prepared. Crystal structures for these complexes show that the Ir-CNHC distances are 2.043(5)-2.056(5) Å. The hydride chemical shifts for complexes bearing C(1)^C^C(1) (-20.6 to -20.3 ppm) are more upfield than those with C(2)^C^C(2) (-19.5 and -19.2 ppm), revealing that C(1)^C^C(1) is a better electron donor than C(2)^C^C(2). Spectroscopic comparisons and time-dependent density functional theory (TD-DFT) calculations suggest that the lowest-energy electronic transition associated with these complexes (λ = 340-530 nm (ε ≤ 10(3) dm(3) mol(-1) cm(-1))) originate from a dπ(Ir(III)) → π*(N^N) metal-to-ligand charge transfer transition, where the dπ(Ir(III)) level contain significant contribution from the C^C^C ligands. All these complexes are emissive in the yellow-spectral region (553-604 nm in CH3CN and CH2Cl2) upon photo-excitation with quantum yields of 10(-3)-10(-1).

Cell therapy for the treatment of tendinopathy--a systematic review on the pre-clinical and clinical evidence.

OBJECTIVES: This review aimed to summarize the current evidence on the safety/efficacy of cell therapy for the treatment of tendinopathy. METHODS: A systematic literature search was conducted using various databases with relevant keywords. Both original animal and human controlled studies, covering any cell type for the treatment of naturally occurring, overuse or collagenase-induced tendinopathy, and with full text available, were included. The quality of all included studies was assessed. Relevant data on study design, safety and efficacy outcomes were extracted. RESULTS: Eleven original studies were selected, of which nine were pre-clinical studies using the collagenase-induced tendon injury model and two were clinical studies. Types of cells, scaffolds, dosages and treatment regimens used varied. All the studies performed cell injection once. A critical appraisal of the included studies showed sub-optimal blinding. Cell therapy was generally reported to be safe, except minor complications, in the short term. Cell therapy was reported to improve tendon architecture in histology but equivocal finding was observed in sonographic/MRI examination, functional and biomechanical performance. CONCLUSIONS: The current evidence was inadequate to make a conclusion whether cell therapy was safe and effective. Further study with adequate sample size and follow-up time, appropriate controls and optimal blinding is required. Confirmation of finding, using different tendinopathy animal models, by systematic investigation of the effects of cell sources, dosages and regimens on the outcomes, and by the inclusion of tendon pain assessment in both animals and human, is recommended. Research on the mechanisms of how cell worked in tendon repair is essential.