Quantitative assessment and influence factors of facial wrinkle situation in male construction workers in Beijing.

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 < .01). The wrinkle score of construction workers between 20 and 29 years old was significantly higher than that of non-construction workers (t = 4.077, P < .01). The facial wrinkle score of construction workers(r = 0.657, P < .01) and non-construction workers (r = 0.681, P < .01) was both positively correlated with age. The wrinkle score of construction workers was related to age, sunlight, and noise(P < .01). CONCLUSION: The wrinkle score of male construction workers between 20 and 29 years old is significantly higher than that of non-construction workers in Beijing. Age, sunlight, and noise were the main influencing factors of wrinkle.

Role of an additional third screw in the fixation of transverse patellar fracture with two parallel cannulated screw and anterior wire.

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.

Biomechanical analysis of different dynamic sitting techniques: an exploratory study.

Prolonged static sitting in wheelchairs increases the risk of pressure ulcers. This exploratory study proposed three dynamic sitting techniques in order to reduce the risk of developing pressure ulcer during wheelchair sitting, namely lumbar prominent dynamic sitting, femur upward dynamic sitting, and lumbar prominent with femur upward dynamic sitting. The purpose of this study was to analyze the biomechanical effects of these three techniques on interface pressure. 15 able-bodied people were recruited as subjects to compare the aforementioned sitting techniques in a random order. All parameters, including dynamic contact area, dynamic average pressure, and dynamic peak pressure on backrest and seat were measured and compared. In result, when compared with lumbar prominent dynamic sitting, femur upward dynamic sitting and lumbar prominent with femur upward dynamic sitting appeared to yield significantly lower dynamic average and peak pressure on the back part of seat, and significantly higher dynamic average and peak pressure on the front part of seat. This study can serve as a reference point for clinical physicians or wheelchair users to identify a suitable dynamic sitting technique.

Roles of the screw types, proximity and anterior band wiring in the surgical fixation of transverse patellar fractures: a finite element investigation.

BACKGROUND: Cannulated screws with an anterior wire are currently used for managing transverse patellar fracture. However, the addition of anterior wiring with various types of screws via open surgery to increase the mechanical stability is yet to be determined. Hence, this study aimed to compare the mechanical behaviors of a fractured patella fixed with various screws types and at various screw locations with and without the anterior wire. The present study hypothesized that using the anterior wire reduces the fracture gap formation. METHODS: A finite element (FE) model containing a fractured patella fixed with various types of cannulated screws and anterior wiring was created in this study. Three types of screws, namely partial thread, full thread, and headless compression screws, and two screw depths, namely 5 and 10 mm away from the anterior surface of the patella, were included. The effect of the anterior wire was clarified by comparing the results of surgical fixation with and without the wire. Two magnitudes and two loading directions were used to simulate and examine the mechanical responses of the fractured patella with various fixation conditions during knee flexion/extension. RESULTS: Compared with partial thread and headless compression screws, the full thread screw increased the stability of the fractured patella by reducing fragment displacement, fracture gap formation, and contact pressure while increasing the contact area at the fracture site. Under 400-N in the direction 45°, the full thread screw with 5-mm placement reduced the gap formation by 86.7% (from 2.71 to 0.36 mm) and 55.6% (from 0. 81 to 0. 36 mm) compared with the partial thread screw with 10-mm placement, respectively without and with the anterior wire. CONCLUSION: The anterior wire along with the full thread screw is preferentially recommended for maintaining the surgical fixation of the fractured patella. Without the use of anterior wiring, the full thread screw with 5-mm placement may be considered as a less invasive alternative; however, simple screw fixation at a deeper placement (10 mm) is least recommended for the fixation of transverse patellar fracture.

Evaluation of the effect of different sitting assistive devices in reclining wheelchair on interface pressure.

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.

Numerical investigation of fracture impaction in proximal humeral fracture fixation with locking plate and intramedullary nail.

INTRODUCTION: Fracture impaction is a surgical technique used to support the fractured humerus with locking plate or intramedullary nail when treating proximal humeral fractures. However, few studies have investigated the mechanical difference between fracture impaction with locking plate and with intramedullary nail. The mechanism of fracture impaction to increase stability is still unclear. The aim of this study was to use numerical methods to compare the biomechanical effect of treating proximal humeral fracture. METHODS: Six different humerus models, including intact and fractured humeri with various fixation patterns were used in this study. Fracture impaction was simulated by moving the distal fragment of the humeral shift upwards directly until touching the inferior surface of the proximal fragment. We also considered both poor- and normal-quality bone in the simulation. RESULTS: Results confirmed that fracture impaction increases fracture stabilityand decreases peak stress in both implant and bone. Also, fracture impaction and plating with medial shift of the humeral shaft provides the highest stability. The metallic implant shared loading with the bone in the impacted models, while implants sustained all the loading alone in the nonimpacted models. CONCLUSIONS: Based on the results, the technique of fracture impaction is suggested for both nail and plate to reduce stresses on bone and implants and to increase structural stability. Furthermore, impaction with medial shift of the humeral shaft with plate is found to achieve the highest stability when treating proximal humeral fractures.

Comparing the effects of different dynamic sitting strategies in wheelchair seating on lumbar-pelvic angle.

BACKGROUND: Prolonged static sitting in a wheelchair is associated with an increased risk of lower back pain. The wheelchair seating system is a key factor of this risk because it affects spinal loading in the sitting position. In this study, 7 dynamic sitting strategies (DSSs) are examined: lumbar prominent dynamic sitting (LPDS), back reclined dynamic sitting (BRDS), femur upward dynamic sitting (FUDS), lumbar prominent with back reclined dynamic sitting (LBDS), lumbar prominent with femur upward dynamic sitting (LFDS), back reclined with femur upward dynamic sitting (BFDS), and lumbar prominent with back reclined with femur upward dynamic sitting (LBFDS). The objective of this study was to analyze the biomechanical effects of these sitting strategies on lumbar-pelvic angles. METHODS: Twenty able-bodied participants were recruited for the study. All participants performed LPDS, BRDS, FUDS, LBDS, LFDS, BFDS, and LBFDS in a random order. All lumbar-pelvic angle parameters, including the static lumbar angle, static pelvic angle, lumbar range of motion, and pelvic range of motion were measured and compared. RESULTS: Results show that LBDS and LBFDS enabled the most beneficial lumbar movements, although the difference between the 2 strategies was nonsignificant. BRDS and BFDS enabled the most beneficial pelvic movements, although the difference between the 2 strategies was nonsignificant. Among all the upright DSSs, LPDS and LFDS enabled the most beneficial lumbar and pelvic movements, although no significant difference was observed between these 2 strategies. CONCLUSIONS: We identified the effects and differences among 7 DSSs on lumbar-pelvic angles. Wheelchair users can choose the most suitable DSS that meets their needs. These findings may serve as a reference for practicing physicians or wheelchair users to choose an appropriate dynamic wheelchair seating system. TRIAL REGISTRATION: ISRCTN12389808 , 18th November 2016, retrospectively registered.

Biomechanical evaluation of a novel wheelchair backrest for elderly people.

BACKGROUND: Back pain is a common complication of wheelchair-bound elderly people. Seating system is a key factor that influences spinal curvature, back muscle activation, interface pressure, and comfortability. A seating system can maintain lumbar lordosis, lower back muscle activity, and decrease ischial tuberosities pressure, which reduces spinal load and directly influences sitting comfort. Our previous study has confirmed that backward thoracic support showed a relatively higher lumbar lordosis and lower back muscle activity. This study intends to evaluate the influence of backward thoracic support on interface pressure and subjective discomfort. METHODS: In this study, 18 elderly men were recruited to participate in a random comparison involving 4 sitting postures. These postures comprised relaxed slouching, flat back support, prominent lumbar support, and backward thoracic support sitting. All parameters, including interface pressure (total contact area, average pressure, and peak pressure on backrest and seat) and subjective discomfort (upper-back, mid-back, lower-back, buttocks, and thighs) were measured and compared. RESULTS: The results showed that compared with other sitting postures, backward thoracic support sitting significantly reduced average pressure and peak pressure on seat and increased average pressure and peak pressure on backrest. Concurrently, subjective discomfort in the upper-back, mid-back, lower-back, and buttocks were reduced. CONCLUSIONS: The results confirmed that backward thoracic support can maintain favorable wheelchair sitting posture, thereby preventing or reducing the risks of back pain. However, this study was no evaluations on shear forces on butts and neck postures. Future studies investigating shear forces on butts and neck postures are required.

Structure-performance correlations of organic dyes with an electron-deficient diphenylquinoxaline moiety for dye-sensitized solar cells.

The high performances of dye-sensitized solar cells (DSSCs) based on seven new dyes are disclosed. Herein, the synthesis and electrochemical and photophysical properties of a series of intentionally designed dipolar organic dyes and their application in DSSCs are reported. The molecular structures of the seven organic dyes are composed of a triphenylamine group as an electron donor, a cyanoacrylic acid as an electron acceptor, and an electron-deficient diphenylquinoxaline moiety integrated in the π-conjugated spacer between the electron donor and acceptor moieties. The DSSCs based on the dye DJ104 gave the best overall cell performance of 8.06 %; the efficiency of the DSSC based on the standard N719 dye under the same experimental conditions was 8.82 %. The spectral coverage of incident photon-to-electron conversion efficiencies extends to the onset at the near-infrared region due to strong internal charge-transfer transition as well as the effect of electron-deficient diphenylquinoxaline to lower the energy gap in these organic dyes. A combined tetraphenyl segment as a hydrophobic barrier in these organic dyes effectively slows down the charge recombination from TiO2 to the electrolyte and boosts the photovoltage, comparable to their Ru(II) counterparts. Detailed spectroscopic studies have revealed the dye structure-cell performance correlations, to allow future design of efficient light-harvesting organic dyes.

Increased serum asprosin is correlated with diabetes mellitus-induced erectile dysfunction.

OBJECTIVE: Asprosin, a newly identified adipokine, is pathologically increased in type 2 diabetes. The aim of this study is to see whether serum asprosin concentrations are linked to diabetes mellitus-induced erectile dysfunction (DMED). METHODS: 90 male patients with type 2 diabetes were included. According to the International Index of Erectile Function (IIEF-5) score, they were classified into two groups: 45 type 2 diabetes patients without erectile dysfunction (DM group) (IIEF-5 > 21),45 patients with diabetes induced erectile dysfunction (DMED group) (IIEF-5 ≤ 21)0.45 healthy male volunteers with normal blood glucose, IIEF-5 score > 21 points, and age matched with the DMED group were included as the control group. Anthropometric and biochemical variables were determined in all participants. RESULTS: When compared to the controls, T2DM ( Type 2 Diabetes Mellitus)patients had higher serum asprosin levels. The DMED group had significantly higher serum asprosin than the T2DM groups(p < 0.001). After adjusting for multiple variables considered traditional risk factors for ED(erectile dysfunction), Asprosin can still be used as an independent risk factor for ED; The ROC(Receive Operating Characteristic Curve) indicates that asprosin has good sensitivity (97.8%) and specificity (62.2%) in predicting ED, with an area under the curve of 0.843.Correlation analysis shows that asprosin is negatively correlated with SOD(superoxide dismutase ) and positively correlated with MDA (malondialdehyde). CONCLUSION: Serum asprosin concentrations are increased in patients with DMED. Also, asprosin is correlated with oxidative stress indexes (MDA, SOD).

Biomechanical comparison of different screw-included angles in crossing screw fixation for transverse patellar fracture in level walking: a quasi-dynamic finite element study.

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.

Surfactant effects on electrochemically durable lead halide perovskite electro-catalysts.

Electrochemically durable perovskite electrodes of nickel foam/TiO2/FA(Pb1-xGex)I3, passivated using various surfactants of tetra-n-alkyl ammonium halides (alkyl = ethyl, butyl, hexyl, or octyl; halide = I, I0.5Br0.5, Br, Br0.5Cl0.5, or Cl), were successfully applied as good electro-catalysts on the counter electrodes in dye-sensitized solar cells (DSSCs). The longer alkyl chain of a surfactant resulted in a higher water contact angle, but poorer film conductivity. Based on the optimal tetra-n-hexyl ammonium (THA) cation, shrinking the halide radius of THA from I to I0.5Br0.5 formed an appropriate amount of FAPbBr3 nano-crystals covering on the FA(Pb1-xGex)I3 grain surface. This phenomenon not only suppressed the perovskite decomposition under electrochemical measurements, but also created additional electro-catalytic active sites for triggering the iodide/triiodide redox reaction. Further shrinking the halide radius of THA from I0.5Br0.5 to Cl resulted in a severe self-aggregation of THACl, leading to an insufficient passivation and thereby poor electrochemical performance. In an ambient environment with a relative humidity higher than 75%, the optimal perovskite electrode of nickel foam/TiO2/FA(Pb1-xGex)I3-THAI0.5Br0.5 maintained the good crystallinity of α-FAPbI3 at least for 6 months, without obvious decomposition. Compared to the DSSC couple with a common counter electrode of nickel foam/Pt (8.74%), a better cell performance of 8.87% was achieved using the counter electrode of nickel foam/TiO2/FA(Pb1-xGex)I3-THAI0.5Br0.5, which was attributed to its good intrinsic electro-catalytic activity, large surface area, multiple active sites, and decent thermodynamic stability. Under room light illumination, higher cell efficiencies were obtained at 1 klux (21.5% for an office), 3 klux (22.9% for a shopping window), and 6 klux (22.3% for a lampshade). There is no doubt that air-stable perovskites have great potential in showing high performance for various electrochemical devices.

[Liquid nitrogen freezing combined with 5-aminolaevulinic acid-photodynamic therapy for condyloma acuminatum in men].

OBJECTIVE: To investigate the efficacy, adverse reaction and prognosis of liquid nitrogen freezing combined with 5-aminolaevulinic acid-photodynamic therapy (ALA-PDT) in the treatment of condyloma acuminatum in men. METHODS: We collected medical histories and conducted physical examinations for 35 male patients with condyloma acuminatum in the outpatient department, and treated them by liquid nitrogen freezing combined with ALA-PDT every 7-10 days. We recorded the skin lesions and adverse events each time and followed up the patients at 4 and 24 weeks after treatment. RESULTS: The 35 patients were aged 17-71 (median 31) years, and their average course of disease was 30-180 (mean 60) days. The skin lesion area was reduced remarkably after 3 times of liquid nitrogen freezing combined with ALA-PDT, 16-140 (median 38) mm2 for the first time, 6-63 (median 13) mm2 for the second, and 0-10 (median 3) mm2 for the third, with statistically significant differences (P < 0.01). Two cases (5.7%) relapsed at 4 weeks and 4 cases (11.4% ) at 24 weeks. CONCLUSION: Liquid nitrogen freezing combined with ALA-PDT is better than either liquid nitrogen freezing or ALA-PDT alone for the treatment of condyloma acuminatum in men.

Triangular configuration with headless compression screws in the fixation of transverse patellar fracture.

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.

Numerical Comparison of Restored Vertebral Body Height after Incomplete Burst Fracture of the Lumbar Spine.

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.

Electroactive and Sustainable Cu-MOF/PEDOT Composite Electrocatalysts for Multiple Redox Mediators and for High-Performance Dye-Sensitized Solar Cells.

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.

Orientation-Adjustable Metal-Organic Framework Nanorods for Efficient Oxygen Evolution Reaction.

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.

Computational comparison of different plating strategies in medial open-wedge high tibial osteotomy with lateral hinge fractures.

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.

Gap between the fragment and the tibia affects the stability of tibial tubercle osteotomy: A finite element study.

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.