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An electrochemically active and air-stable FA(Pb1−xGex)I3 perovskite was supported by effective passivation with tetra-n-hexylammonium (THA) iodide/bromide, providing a hydrophobic surface by the THA cation and forming FAPbBr3 by the mixed halide.

A triangular configuration with three parallel cannulated screws is an established treatment for fixing transverse patellar fractures; however, the stability achieved with this approach is slightly lower than that attained with cannulated screws combined with anterior wiring. In the present study, triangular configurations were modified by partially or totally replacing the cannulated screws with headless compression screws (HCSs). Through finite element simulation involving a model of distal femoral, patellar, and proximal tibial fractures, the mechanical stability levels of the modified triangular configurations were compared with that of two cannulated screws combined with anterior wiring. Four triangular screw configurations were developed: three HCSs in a forward and backward triangular configuration, two deep cannulated screws along with one superficial HCS, and two superficial cannulated screws with one deep HCS. Also considered were two parallel cannulated screws (inserted superficially or deeply) combined with anterior wiring. The six approaches were all examined in full knee extension and 45° flexion under physiological loading. The highest stability was obtained with the three HCSs in a backward triangular configuration, as indicated by the least fragment displacement and the smallest fracture gap size. In extension and flexion, this size was smaller than that observed under the use of two deeply placed parallel cannulated screws with anterior wiring by 50.3% (1.53 vs. 0.76 mm) and 43.2% (1.48 vs. 0.84 mm), respectively. Thus, the use of three HCSs in a backward triangular configuration is recommended for the fixation of transverse patellar fractures, especially without the use of anterior wiring.

Hierarchical 3D CoP micro-pompon assembled by 1D-nano-needle-array decorated 2D-micro-sheets provided facile charge transfer and lots of electrocatalytic active sites to deliver decent DSSC performance (8.80% at 1 sun; 17.27% at 7 klux).

Background A minimally invasive technique with various screw configurations without open surgery is currently used for the fixation of transverse patellar fractures. Percutaneous crossing screw configuration has been reported to have a good bone union rate in patellar fractures. However, the difference in mechanical stability of the fractured patella between different screw-included angles has not been fully investigated. Hence, this study aims to compare the mechanical stability of parallel and crossing screw fixations with different screw-included angles for the fixation of transverse patellar fractures during level walking. Methods A finite element knee model containing a patella with a transverse fracture is created. Two headless compression screws with different angles (0°, 30°, 60°, and 90°) are used to fix the fracture. The loading conditions of the knee joint during level walking are used to compare the stability of the fractured patella with different fixation screw configurations. Results The results indicate that the maximum fracture gap opening distance increased with an increase in the included angle. Two parallel screws yield the smallest gap distance among all screw configurations. The maximum gap opening distances at the anterior leading edge of the fractured patella with two parallel screws and two screws having an included angle of 90° are 0.73 mm and 1.31 mm, respectively, at 15% walking cycle. Conclusions Based on these results, the superior performance of two parallel screws over crossing screw fixations in the fixation of transverse patellar fractures is established. Furthermore, the smaller the angle between the crossing screws, the better is the stability of the fractured patella.

Organic dyes used as sensitizers in dye-sensitized solar cells offer endless opportunities for modulation of cell efficiency through structural diversifications. Despite the countless number of dyes developed, structure-property analysis by varying chromophores and their topology in dyes is useful to formulate design principles. Herein, we report six new organic dyes featuring dithienopyrrole (DTP), benzothiadiazole (BTD) and cyanoacrylic acid units. The effect of auxiliary donors such as triphenylamine or diphenylaminofluorene and the position of benzothiadiazole on the optical and photovoltaic properties were evaluated by appropriate design of dyes. Incorporation of additional donor enhanced the spectral response of the dyes by elongating the conjugation length and supplementing the donor-acceptor interaction. Moving the BTD unit from the position between DTP and acceptor (D-D-A-π-A) to a position between the auxiliary donor and DTP (D-A-D-A) altered the absorption as well as electrochemical properties. Theoretical calculations revealed that the later molecular configuration ensures sufficient overlap of HOMO and LUMO and facilitate the charge transfer propensity from arylamine donor to acceptor which is beneficial for light harvesting. Among the dyes, a D-A-D-A dye possessing triphenylamine exhibited highest power conversion efficiency (η = 7.57%). The structure-property relationship is supported by electron transfer kinetics elucidated by electrochemical impedance spectroscopic studies. The best performing dye displayed high charge recombination and sufficiently low charge transfer resistance in the device.

Evacuation navigation in emergencies such as fires is one of the most important operational considerations for a building. The large and complicated interior spaces, as well as the intensive popula...

Boron nitride (BN) is newly introduced as a non-metal electro-catalyst for the counter electrode of a dye-sensitized solar cell (DSSC). By applying a conductive binder of sulfonated poly(thiophene-...

Posterior lumbar interbody fusion (PLIF) with a spacer and posterior instrument (PI) via minimally invasive surgery (MIS) restores intervertebral height in degenerated disks. To align with MIS, the spacer has to be shaped with a slim geometry. However, the thin spacer increases the subsidence and migration after PLIF. This study aimed to propose a new lumbar fusion approach using bone cement to achieve a larger supporting area than that achieved by the currently used poly aryl-ether-ether-ketone (PEEK) spacer and assess the feasibility of this approach using a sawbone model. Furthermore, the mechanical responses, including the range of motion (ROM) and bone stress with the bone cement spacer were compared to those noted with the PEEK spacer by finite element (FE) simulation. An FE lumbar L3-L4 model with PEEK and bone cement spacers and PI was developed. Four fixing conditions were considered: intact lumbar L3-L4 segment, lumbar L3-L4 segment with PI, PEEK spacer plus PI, and bone cement spacer plus PI. Four kinds of 10-NM moments (flexion, extension, lateral bending, and rotation) and two different bone qualities (normal and osteoporotic) were considered. The bone cement spacer yielded smaller ROMs in extension and rotation than the PEEK spacer, while the ROMs of the bone cement spacer in flexion and lateral bending were slightly greater than with the PEEK spacer. Compared with the PEEK spacer, peak contact pressure on the superior surface of L4 with the bone cement spacer in rotation decreased by 74% (from 8.68 to 2.25 MPa) and 69.1% (from 9.1 to 2.82 MPa), respectively, in the normal and osteoporotic bone. Use of bone cement as a spacer with PI is a potential approach to decrease the bone stress in lumbar fusion and warrants further research.

Background and objectives: Vertebral compression fracture is a major health care problem worldwide due to its direct and indirect negative influence on health-related quality of life and increased health care costs. Although a percutaneous surgical intervention with balloon kyphoplasty or metal expansion, the SpineJack, along with bone cement augmentation has been shown to efficiently restore and fix the lost vertebral height, 21–30% vertebral body height loss has been reported in the literature. Furthermore, the effect of the augmentation approaches and the loss of body height on the biomechanical responses in physiological activities remains unclear. Hence, this study aimed to compare the mechanical behavior of the fractured lumbar spine with different restored body heights, augmentation approaches, and posterior fixation after kyphoplasty using the finite element method. Furthermore, different augmentation approaches with bone cement and bone cement along with the SpineJack were also considered in the simulation. Materials and Methods: A numerical lumbar model with an incomplete burst fracture at L3 was used in this study. Two different degrees of restored body height, namely complete and incomplete restorations, after kyphoplasty were investigated. Furthermore, two different augmentation approaches of the fractured vertebral body with bone cement and SpineJack along with bone cement were considered. A posterior instrument (PI) was also used in this study. Physiological loadings with 400 N + 10 Nm in four directions, namely flexion, extension, lateral bending, and axial rotation, were applied to the lumbar spine with different augmentation approaches for comparison. Results: The results indicated that both the bone cement and bone cement along with the SpineJack could support the fractured vertebral body to react similarly with an intact lumbar spine under identical loadings. When the fractured body height was incompletely restored, the peak stress in the L2–L3 disk above the fractured vertebral body increased by 154% (from 0.93 to 2.37 MPa) and 116% (from 0.18 to 0.39 MPa), respectively, in the annular ground substance and nucleus when compared with the intact one. The use of the PI could reduce the range of motion and facet joint force at the implanted levels but increase the facet joint force at the upper level of the PI. Conclusions: In the present study, complete restoration of the body height, as possible in kyphoplasty, is suggested for the management of lumbar vertebral fractures.

A series of orientation-adjustable metal-organic framework (MOF) nanorods, CoFe(dobpdc)-I to CoFe(dobpdc)-III (dobpdc = 4,4'-dihydroxybiphenyl-3,3'-dicarboxylate), is developed on a 3D nickel foam (NF) template. By modulating the solvent composition for synthesis, the feature of MOF nanorods on the template can be varied from disorganized to a unidirectional orientation perpendicular to the NF. Well-aligned, vertically oriented CoFe(dobpdc)-III nanorods are hydrophilic and have more exposed active sites and interfacial charge transfer ability. Consequently, they exhibit a superior activity for oxygen evolution reaction (OER) with ultralow overpotentials of 176 and 240 mV at 10 and 300 mA cm-2 in 1.0 M KOH (aq), respectively. CoFe(dobpdc)-III also shows a record low overpotential of 204 mV at J10 mA cm-2 among the electrocatalysts based on CoFe MOF and an excellent overpotential at a high current density (100 mA cm-2) of 312 mV in 0.1 M KOH (aq). This is the first report of a convenient method to straighten up MOF nanorods on a template for highly efficient OER.

OBJECTIVE To investigate current situation of facial wrinkles of male construction workers in Beijing area and to discuss the correlative factors. MATERIALS AND METHODS A total of 149 male construction works and 63 male non-construction workers in Beijing were required to complete a questionnaire on their exposure to sunlight, dust, noise, and heat in their workplace environment. Their facial wrinkle scores were measured by VISIA Complexion Analysis System. The two-sample t test, chi-square test, and multiple linear regression were used for statistical analysis RESULTS: The exposure to sunlight, dust, noise, and heat of construction workers was significantly higher than that of non-construction workers (P

Three triazine-cored organic dyes containing triarylamine donor and cyanoacrylic acid acceptor were synthesized and used as sensitizers in dye-sensitized solar cells. Mono- and dianchoring dyes were designed by varying the number of donor/acceptor arms and conjugation length of the acceptor arm to study the effect of molecular structure on charge transfer characteristics and photovoltaic performance. They exhibited intense longer wavelength absorption with high molar extinction coefficients tunable depending on the number of acceptor arms and the nature of its composition. The electron accepting triazine linker favorably alters the energies of the frontier molecular orbitals which facilities the electron injection into the conduction band of TiO2 and dye regeneration by the electrolyte. A dye containing two donor arms and a acceptor composed of bithiophene spacer displayed promising power conversion efficiency (4.29%) in the series owing to high photocurrent density and open circuit voltage arising from the comparatively low charge transfer resistance and high recombination resistance in the device.

Tibial tubercle osteotomy (TTO) is commonly performed in cases of complicated juxta-articular trauma or revision total knee arthroplasty. However, strategies for firmly fixing the resulting osteotomy bone fragment are not sufficiently understood. This study aims to investigate the effect of the location of the gap between the fragment and the tibia and with various fixed screw configurations on TTO stability, contact force on the fragment, and bone stress by using the finite element method. A TTO model with a 1-mm gap, either above or below the fragment, was developed. Furthermore, five screw configurations, including two parallel horizontal screws placed at 20- and 30-mm intervals, two parallel downward screws, two trapezoid screws, and two divergent screws, were used. A vertically upward 1600-N force was applied on the tibial tubercle to mimic a worst-case condition. Placing the fragment close to the superior cutting plane (above the gap) yielded greater stability and less stress on the bone than did placing it close to the inferior cutting plane. The superior cutting plane of the tibia generated the largest contact force on the superior plane of the fragment for static balance under loading. Additionally, among all screw configurations, the configuration involving two parallel downward screws resulted in the highest stability but also the greatest stress on the cortical bone. The fragment obtains a solid barrier and support from the tibia immediately after surgery to against the patellar tension force when the fragment is close to the superior cutting plane of the tibia.

A hierarchical urchin-like structure of CoSe2/CoSeO3 (denoted as CoSe2/CoSeO3-UL) is synthesized by a one-step hydrothermal method and investigated as the electro-catalyst for the counter electrode (CE) of dye-sensitized solar cells (DSSCs). The evolution of the CoSe2/CoSeO3 nanostructures as a function of the synthesis time has been identified by scanning electron microscopy. The growth mechanism is proposed and the desired CoSe2/CoSeO3 hierarchical UL structure is noticed at 4 h. CoSe2/CoSeO3-UL consists of nanoparticles and hexagonal prisms for providing a high surface area for catalytic reactions and a one dimensional charge transport route, respectively. The results show that DSSCs using the CoSe2/CoSeO3-UL CE exhibit a higher power conversion efficiency (η) of 9.29 ± 0.24% than that of the cell using a Pt CE (8.33 ± 0.07%). Under various dim light conditions (i.e., a T5 lamp), the DSSC with the CoSe2/CoSeO3-UL CE shows outstanding η's of 19.88 ± 0.10%, 18.24 ± 0.06%, and 16.00 ± 0.13% at 7000 lux (2.21 mW cm−2), 6000 lux (1.89 mW cm−2) and 4800 lux (1.55 mW cm−2), respectively. This study demonstrates that CoSe2/CoSeO3-UL has great potential to replace Pt in DSSCs, and the application of DSSCs can be extended from outdoor to indoor conditions.

In this paper, organic dyes containing dithienopyrrole (DTP) donor, linkers such as thiophene or dithienopyrrole and cyanoacrylic acid acceptor are reported. The impact of different π-linkers on photophysical, electrochemical and photovoltaic properties is studied. The dyes containing dithienopyrrole linker showed improved light harvesting efficiency and reduced oxidation potentials than the thiophene analogs. The major absorption originates from the charge transfer transition, which shifts progressively to red region on increasing the number of heteroaromatic linkers. Additionally, the presence of N-fluorenyldithieonopyrrole in the conjugation bridge is beneficial to retard the charge recombination process. Therefore, the dye containing a dithienopyrrole linker showed the highest efficiency of 5.94% in the series attributable to its high JSC and VOC values. However, a dye containing two dithienopyrrole units in the conjugation pathway exhibited low power conversion efficiency irrespective of its intense absorption attributable to the low charge collection efficiency and reduced electron lifetime.

Cost effective imidazole-based star-shaped oligo(arylamines) were easily prepared in good yields via the reaction of one precursor containing two or more aldehydes with a dione compound having two arylamines. High performance perovskite (MAPbI3) solar cells with a conventional cell configuration were fabricated using these compounds as dopant-free hole transport materials. The best solar-to-electricity conversion efficiency reached ∼17.5%, which surpassed that based on LiTFSI/t-BP doped spiro-OMeTAD. The cell also exhibited much better temporal stability than the standard cell of LiTFSI/t-BP doped spiro-OMeTAD, as no hydrophilic dopants are needed.

Double-anchored phenothiazine-cored sensitizers (YL1–YL4) having a tetraphenylethylene (TPE) entity as the N-substituent with various π-spacers (thiophene, 3-hexylthiophene, 4-hexyl-2,2′-bithiophene, and 4-heptyl-4-hexyl-4H-cyclopenta[2,1-b:3,4-b′]dithiophene) are prepared for dye-sensitized solar cells (DSSCs). The YL4-based DSSC exhibits the best solar-to-electricity conversion efficiency of up to 9.79% and 10.87%, respectively, without and with the CDCA co-adsorbent. These values outperform the efficiencies of cells based on N719 (8.77%) and our previous outstanding double-anchored phenothiazine-cored dye (HL5, 8.53%). YL dyes possess double layered shelters for efficient blockade of dark current: the inner shelter from the dianchor skeleton and the outer shelter from clogged TPE units. Clogged TPEs also strengthen dye stability on the TiO2 surface. Under room light illumination (Philips T5 lamp), the YL4-based DSSC device exhibited high cell efficiencies of 27.54%, 26.81%, and 24.98% at 187 lux, 597 lux, and 1025 lux, respectively, showing great potential towards the Internet of Things (IoTs).

Background To maintain the corrected alignment after high tibial osteotomy (HTO), fixation with titanium locking plate and screws is widely used in current practice; however, screw breakage is a common complication. Thus, this study was to investigate the mechanical stability of HTO with locking plate and various screw fixations, including the length as well as the type. Methods A finite element (FE) model involving a distal femur, meniscus, and a proximal tibia with HTO fixed with a titanium locking plate and screws was created. The angle of the medial open wedge was 12°, and bone graft was not used. Two types of screws, namely conventional locking and far-cortical locking screws, with various lengths and configurations were used. At the proximal tibia, conventional locking screws with different lengths, 30 and 55 mm, were used; at the tibia shaft, different screw fixations including one-cortical, two-cortical, and far-cortical locking screws were used. Results The use of far-cortical locking screw generated the highest equivalent stress on the screws, which was four times (from 137.3 to 541 MPa) higher than that of the one-cortical screw. Also, it led to the maximum deformation of the tibia and a greater gap deformation at the osteotomy site, which was twice (from 0.222 to 0.442 mm) larger than that of the one-cortical screw. The effect of different locking screw length on tibia deformation and implant stress was minor. Conclusion Thus, far-cortical locking screws and plates increase interfragmentary movement but the screw stress is relatively high. Increasing the protection time (partial weight duration) is suggested to decrease the risk of screw breakage in HTO through fixation with titanium far-cortical locking screws and plates.

An electrically conductive Cu-MOF, {[Cu2(6-mercaptonicotinic acid)(6-mercaptonicotinate)]·NH4}n, was successfully electrodeposited on the conductive substrates via using poly(3,4-ethylenedioxythiophene) (PEDOT) as the binder. Multiple functionalities of the Cu-MOF microparticle within the Cu-MOF/PEDOT composite electrode were systematically vindicated as (1) releasing the cohesive strength among the PEDOT matrix, thus enhancing the film adhesion to substrate, (2) providing excellent intrinsic heterogeneous rate constant via lowering the reaction active energy, (3) supplying numerous active sites at the center or edges on its (-Cu-S-)n honeycomb-like planes, (4) facilitating the electron transfer through its two-dimensional (-Cu-S-)n plains, and (5) benefiting the penetration of the redox mediators through its porous frameworks. In multiple redox mediators (i.e., I-/I3-, cobalt(II/III)-complex, and copper(I/II)-complex), the composite Cu-MOF/PEDOT electrode exhibited superior electrocatalyst activity and kept almost 100% of its initial redox peak currents after continuous cyclic voltammetric scanning for 300 cycles. As a high-performance electrocatalyst for the counter electrode in dye-sensitized solar cells (DSSCs), the composite Cu-MOF/PEDOT electrode rendered its cell a decent solar-to-electricity conversion efficiency of up to 9.45% at 1 sun and 22.80% at room light illumination. Compared to the traditional platinum electrode (7.67%), the low-cost Cu-MOF/PEDOT composite electrode has great possibility to be used for various electrochemical devices and the Internet-of-things applications.

Background Two parallel cannulated screws along with an anterior wire to construct a tension band is a popular approach in transverse patellar fractures. However, the optimal screw proximity, either deep or superficial screw placements, remains controversial. Hence, a new concept of the addition of a third screw to form a triangular configuration along with the original two parallel screws was proposed in this study. Therefore, the biomechanical effect of the additional third screw on the stability of the fractured patella was investigated with finite element (FE) simulation. Methods An FE knee model including the distal femur, proximal tibia, and fractured patella (type AT/OTA 34-C) was developed in this study. Four different screw configurations, including two parallel cannulated screws with superficial (5-mm proximity) and deep (10-mm proximity) placements and two parallel superficial screws plus a third deep screw, and two parallel deep screws plus a third superficial screw, with or without the anterior wire, were considered for the simulation. Results Results indicated that the addition of a third screw increased stability by reducing the dorsal gap opening when two parallel screws were deeply placed, particularly on the fractured patella without an anterior wire. However, the third screw was of little value when two parallel screws were superficially placed. In the existence of two deep parallel screws and the anterior wire, the third screw reduced the gap opening by 23.5% (from 1.15 mm to 0.88 mm) and 53.6% (from 1.21 mm to 0.61 mm) in knee flexion 45° and full extension, respectively. Furthermore, in the absence of the anterior wire, the third screw reduced the gap opening by 73.5% (from 2 mm to 0.53 mm) and 72.2% (from 1.33 mm to 0.37 mm) in knee flexion 45° and full extension, respectively. Conclusion Based on the results, a third cannulated screw superficially placed (5-mm proximity) is recommended to increase stability and maintain contact of the fractured patella, fixed with two parallel cannulated screws deeply placed (10-mm proximity), particularly when an anterior wire was not used. Furthermore, the third screw deeply placed is not recommended in a fractured patella with two parallel superficial screws.

Background Lateral hinge fracture (LHF) is associated with nonunion and plate breakage in high tibial osteotomy (HTO). Mechanical studies investigating fixation strategies for LHFs to restore stability and avoid plate breakage are absent. This study used computer simulation to compare mechanical stabilities in HTO for different LHFs fixed with medial and bilateral locking plates. Methods A finite element knee model was created with HTO and three types of LHF, namely T1, T2, and T3 fractures, based on the Takeuchi classification. Either medial plating or bilateral plating was used to fix the HTO with LHFs. Furthermore, the significance of the locking screw at the combi hole (D-hole) of the medial TomoFix plate was evaluated. Results The osteotomy gap shortening distance increased from 0.53 to 0.76, 0.79, and 0.72 mm after T1, T2, and T3 LHFs, respectively, with medial plating only. Bilateral plating could efficiently restore stability and maintain the osteotomy gap. Furthermore, using the D-hole screw reduced the peak stress on the medial plate by 28.7% (from 495 to 353 MPa), 26.6% (from 470 to 345 MPa), and 32.6% (from 454 to 306 MPa) in T1, T2, and T3 LHFs, respectively. Conclusion Bilateral plating is a recommended strategy to restore HTO stability in LHFs. Furthermore, using a D-hole locking screw is strongly recommended to reduce the stress on the medial plate for lowering plate breakage risk.

Augmented reality (AR), which requires a spatial registration technique, has proved to greatly improve the efficiency of facility maintenance management (FMM) activities. Being one of the most promising techniques for indoor localization, Wi-Fi fingerprinting has been widely used for AR spatial registration. However, localization accuracy of Wi-Fi fingerprinting decreases over time due to dynamics of environmental factors. Readings from different mobile devices can also affect the accuracy negatively. In this paper, a transfer learning technique named transferable CNN-LSTM is proposed for improving the robustness of Wi-Fi fingerprinting while implementing AR in FMM activities. Convolutional neural network (CNN), embedded with long short term memory (LSTM) networks, is utilized to predict the location of unlabeled fingerprints. Multiple kernel variant of maximum mean discrepancy (MK-MMD) is adopted to reduce the distribution difference between the source domain and the target domain, so that the location of the newly collected unlabeled fingerprints can be predicted accurately. As shown in the experimental validation, the transferable CNN-LSTM can achieve an accuracy of 97.1% in short-term (without significant environmental changes) spatial registration, 87.8% in long-term (with significant environmental changes) spatial registration, and around 90% in multi-device spatial registration, indicating a higher accuracy and better robustness over other conventional approaches.

Three novel polymeric ionic liquids (PILs), denoted as PFII-F, PFII-E, and PFII-S, are successfully synthesized by grafting different molar ratios (one-fourth, one eighth, and one sixteenth, respectively) of 1-butylimidazolium iodide onto poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). These PFII PILs are fabricated as polymer membranes via a simple electrospinning technique, which are used as the electrolyte for quasi-solid-state (QSS) dye-sensitized solar cells (DSSCs). The PFII membranes have multiple functions including: (1) encapsulation of the liquid electrolyte with good charge transfer and ionic conductivity properties, (2) chelation of Li+ through the lone pair electrons on their fluoride atoms, and (3) filling the dye-uncovered TiO2 surface with their imidazolium segment. Function (1) endows DSSCs with prominent long-term stability, while functions (2) and (3) suppress the dark current. The best QSS-DSSC with the PFII-F membrane shows a larger open-circuit voltage (VOC), comparable short-circuit current density (JSC), better power conversion efficiency (η) of 9.26%, and superior long-term stability (up to 97% of its initial η) over 1500 h compared to the cell with standard liquid electrolyte (8.63%).

Cobalt diselenide/cobalt selenite (CoSe2/CoSeO3 ) composite crystals with nanocube (NC), nanorod (NR), and nanoparticle (NP) structures were obtained through a microemulsion-assisted hydrothermal synthesis by incorporating the anionic surfactant docusate sodium salt (AOT), the cationic surfactant cetyltrimethyl ammonium bromide (CTAB), and the non-ionic surfactant Triton ® X-100, respectively. The as-prepared CoSe2/CoSeO3 crystals were utilized as the electrocatalysts in dye-sensitized solar cells (DSSCs). Among all the crystals, the one obtained through Triton ® X-100 enables its DSSC to achieve the best power conversion efficiency (η ) of 9.27%, which is even better than that of the DSSC with platinum (Pt) (7.91%). The catalytic abilities of the counter electrodes were analyzed by cyclic voltammetry (CV), Tafel polarization plots, and electrochemical impedance spectra (EIS). The photovoltaic behaviors are substantiated by incident photon-to-electron conversion efficiency (IPCE) spectra. The DSSC with CoSe 2/CoSeO3-NP exhibited an η of 9.27% at 100 mW cm−2, a better η of 9.31% at 50 mW cm−2, and the best η of 9.41% at 10 mW cm−2, thereby extending the scope of application of this DSSC from outdoor to indoor regions. The earth abundant, low-cost material of CoSe2/CoSeO3-NP can be a promising electrocatalytic material to replace the expensive Pt in a DSSC.

Series of dendritic building blocks (G series) with various periphery alkyl chain lengths (C3, C10 and C18) were prepared via convergent synthesis route through reaction-selective building block, (4-Isocyanato-4′(3,3-dimethyl-2,4-dioxo-azetidino)diphenylmethane, IDD) and diethylenetriamine (DETA) via alternative addition and ring-opening reaction. These azetidine-2,4-dione containing dendritic building blocks then reacted with several amino acid compounds to generate the corresponding dendritic co-adsorbents (GA series). GA series comprising different generations, various alkyl chain lengths closed to anchor and/or in the periphery are discussed and applied into dye-sensitized solar cells (DSSCs). The cells utilized similar phenothiazine-based dyes (HL5) as sensitizer with fixed concentration (0.3 mM) of co-adsorbents are fabricated to explore the effect on cell performances and interfacial charge properties. Power conversion efficiencies (PCEs) of 7.02–7.76% were achieved, which better than the commercially available CDCA co-adsorbent based cell (6.71% ± 0.14%). In addition, the highest conversion efficiency also reaches 95% of the standard cell based on N719 metal dye. Herein, several observations: (1) under various alkyl chain lengths closed to anchor, the longest one has efficient charge recombination; (2) under various alkyl chain lengths in the periphery, the moderate one has the best interfacial properties with the longest electron lifetime value; (3) under different generations, the largest one can reduce dye aggregation and charge recombination significantly. Based on our pervious initial study on dendritic co-adsorbents, we further investigated several molecular design on dendritic co-adsorbents to realize the structural effect on cell performance that might be useful for DSSC applications.

Organic sensitizers containing dithienopyrrole donor, benzotriazole or quinoxaline in the conjugation pathway, and cyanoacrylic acid acceptor featured in a donor–acceptor-π–acceptor configuration are reported. The effect of the nature of different conjugating bridges on photophysical, electrochemical and photovoltaic properties was systematically evaluated. The incorporation auxiliary acceptors broadened the absorption spectra and modulated the excited state energy levels. The DFT calculation unraveled a significant overlap of HOMO and LUMO orbitals in benzotriazole-containing dyes and the charge transfer character for the longer wavelength absorption. Among the dyes, a dye containing benzotriazole and thiophene in the conjugation pathway exhibited highest power conversion efficiency attributable to efficient electron injection and pronounced inhibition of electron recombination.

Background Reclining wheelchair users often add one or more sitting assistive devices to their wheelchairs, but the effect of these additional sitting assistive devices on the risk of pressure ulcers has rarely been investigated. This study examined the four modes of reclining wheelchair without and with different sitting assistive devices, namely the back reclined mode, the lumbar support with back reclined mode, the femur upward with back reclined mode, and the lumbar support with femur upward with back reclined mode, in terms of their effects on human-wheelchair interface pressure. Methods This study recruited 16 healthy participants to undergo the aforementioned four modes in random order and have their human-wheelchair interface pressure measured. The initial setting of experimental reclining wheelchair backrest was pushed backward to reach a 150° recline. The data on interface pressure were collected for 5 s while the participant maintained a stable sitting position. The contact area, average pressure, and peak pressure on the back area, ischial area, and femur area were recorded and calculated. Results Among all tested modes, the lumbar support with femur upward with back reclined mode provided the most significant reduction in stress load on the ischial area (P ≤ 0.010) and shifted part of the load to the femur area (P ≤ 0.009). Conclusions This study quantified the effects of and differences between various reclining wheelchair–sitting assistive device combination modes. These findings are useful for the decision-making processes of rehabilitation physicians, wheelchair users, and manufacturers.

We have synthesized a metal-free composite ink that contains graphene dots (GDs) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) that can be used on paper to serve as the counter electrode in a flexible dye-sensitized solar cell (DSSC). This paper-based GD/PEDOT:PSS electrode is low-cost, light-weight, flexible, environmentally friendly, and easy to cut and process for device fabrication. We determined the GD/PEDOT:PSS composite effectively fills the dense micro-pores in the paper substrate, which leads to improved carrier transport in the electrode and a 3-fold enhanced cell efficiency as compared to the paper electrode made with sputtered Pt. Moreover, the DSSC with the paper electrode featuring the GD/PEDOT:PSS composite did not fail in photovoltaic tests even after bending the electrode 150 times, whereas the device made with the Pt-based paper electrode decreased in efficiency by 45% after such manipulation. These exceptional properties make the metal-free GD/PEDOT:PSS composite ink a promising electrode material for a wide variety of flexible electronic applications.