► Silver/iron oxide nanoparticles were synthesized via a facile one-pot green process. ► Arginine created a solution of pH 10 and acted as a reducing agent. ► Good catalytic activity and stability ...for 4-nitrophenol reduction were demonstrated. ► This magnetically recoverable silver nanocatalyst was useful in wastewater treatment.
Silver/iron oxide composite nanoparticles have been synthesized successfully via a facile one-pot green route by the use of l-arginine, which created an aqueous solution of about pH 10 and acted as a reducing agent for the successive formation of iron oxide and Ag nanoparticles. The product was characterized to be silver-coated iron oxide and iron oxide hydroxide composite nanoparticles with a mean diameter of about 13.8±3.0nm and 8.53% of Ag in weight. It exhibited good catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol with sodium borohydride. The reduction reaction followed the pseudo-first-order kinetics. The corresponding rate constants increased with the increases of temperature and catalyst amount but decreased with the increase of initial 4-NP concentration, revealing an activation energy of 28.2kJ/mol and a diffusion controlled mechanism. In addition, this product had quite good stability. No significant activity loss was observed after reuse for 5 cycles.
To determine whether intravenous administration of tranexamic acid (TXA) before shoulder arthroscopic rotator cuff repair surgery can improve arthroscopy visual clarity.
This was a prospective, ...double-blind, randomized, and placebo-controlled study. From May 2016 to April 2018, patients requiring arthroscopic rotator cuff repair were enrolled and randomly assigned to either the TXA group. receiving 1000 mg of TXA intravenously 10 minutes before surgery. or the placebo group. receiving the same volume of plain saline. Patients with pre-existing liver/renal disease, coagulopathy, or concurrent use of anticoagulation medications were excluded. Visual clarity was rated using a Numeric Rating Scale from grade 1 (poor) to grade 3 (clear) every 15 minutes throughout the surgery. Secondary outcomes included estimated perioperative blood loss, operative time, degree of shoulder swelling, postoperative subjective pain score, inpatient duration, and associated comorbidities were recorded. Both parametric and nonparametric methods were used for the statistical analysis.
In total, 72 patients were enrolled, 37 in the TXA group and 35 in the placebo group. The demographic data were similar between the 2 groups. Visual clarity was found to be significantly better in the TXA group, with a greater percentage of grade 3 vision clarity (53.7 ± 18.9 % vs 40.5 ± 22.1%, P = .036). The average visual score in the TXA group (2.5 ± 0.2) also was better than that of the control group (2.3 ± 0.3) (P = .048). The postoperative subjective pain score was significantly lower in the TXA group (3.0 ± 1.5) than in the control group (4.3 ± 2.0) (P = .009). In addition, postoperative analgesic usage was significant lower in the TXA groups (9.6 ± 9.7 morphine milligram equivalent) than in the control group (14.7 ± 13.4 morphine milligram equivalent) (P = .037). Other parameters, such as operative time, estimated perioperative blood loss, degree of shoulder swelling, and duration of inpatient stay were similar between the 2 groups. None of the patients developed complications after surgery.
Intravenous administration of TXA is an alternative way to improve visual clarity in arthroscopic shoulder surgery. It also reduces subjective pain and analgesic consumption in the early postoperative period without significant side effects.
Therapeutic studies level II.
In this paper, a personalized recommendation-based mobile language learning approach is proposed. A mobile learning system has been developed based on the approach by providing a reading material ...recommendation mechanism for guiding EFL (English as Foreign Language) students to read articles that match their preferences and knowledge levels, and a reading annotation module that enables students to take notes of English vocabulary translations for the reading content in individual or shared annotation mode. To evaluate the effectiveness of the proposed approach, an experiment was conducted on a senior high school English course by assigning three classes of students to two experimental groups and a control group. One experimental group learned with the recommendation system with the individual annotation function, the other experimental group learned with the recommendation system with the shared annotation function, while the students in the control group learned with the individual annotation function, but without the recommendation system. The experimental results show that both experimental groups outperformed the control group, but there was no difference in learning outcome between the two experimental groups in terms of learning achievements.
► A personalized recommendation-based mobile learning approach is proposed. ► An experiment was conducted in English reading course. ► The approach improved the students' reading comprehension. ► The approach reduced the students' cognitive loads. ► The students highly accepted the new approach.
In nature, in order to prevent attention from predators, the eyes of night-flying moths have evolutionarily developed an antireflective ability. The surfaces of their eyes are covered with a layer of ...a sub-wavelength structure that eliminates reflections of visible light. This layer allows the eyes of moths to escape detection in darkness, without reflections that could reveal the position of the moths to potential predators. In this study, we proposed a novel procedure for manufacturing a non-close-packed polystyrene (PS) nanosphere monolayer by combining the Langmuir–Blodgett (LB) deposition technique and oxygen plasma treatment. An antireflective structure was replicated from the sub-wavelength structure of moth eyes onto the surface of a glass substrate by nano-imprinting lithography; the structure also displayed hydrophobic properties. The Fresnel reflection of the replicated sub-wavelength structure is near the theoretical prediction from the effective medium theory model. The biomimetic moth-eye structure can be applied to solar cells, monitors, light-emitting diodes, and other optical devices in the future.
A nanocomposite of silver nanoparticles/reduced graphene oxide (Ag/rGO) has been fabricated as a surface-enhanced Raman scattering (SERS) substrate owing to the large surface area and two-dimensional ...nanosheet structure of rGO. A facile and rapid microwave-assisted green route has been used for the formation of Ag nanoparticles and the reduction of graphene oxide simultaneously with L-arginine as the reducing agent. By increasing the cycle number of microwave irradiation from 1 and 4 to 8, the mean diameters of Ag nanoparticles deposited on the surface of rGO increased from 10.3 ± 4.6 and 21.4 ± 10.5 to 41.1 ± 12.6 nm. The SERS performance of Ag/rGO nanocomposite was examined using the common Raman reporter molecule 4-aminothiophenol (4-ATP). It was found that the Raman intensity of 4-ATP could be significantly enhanced by increasing the size and content of silver nanoparticles deposited on rGO. Although the Raman intensities of D-band and G-band of rGO were also enhanced simultaneously by the deposited Ag nanoparticles which limited the further improvement of SERS detection sensitivity, the detectable concentration of 4-ATP with Ag/rGO nanocomposite as the SERS substrate still could be lowered to be 10
−10
M and the enhancement factor could be increased to 1.27 × 10
10
. Furthermore, it was also achievable to lower the relative standard deviation (RSD) values of the Raman intensities to below 5%. This revealed that the Ag/rGO nanocomposite obtained in this work could be used as a SERS substrate with high sensitivity and homogeneity.
Abstract
Background
The optimal surgical technique for the fixation of inferior pole patellar fracture remains controversial. The aims of this study were (1) to compare clinical and radiological ...outcomes following fixation of inferior pole patellar fracture by using tension band wire (TBW) and transosseous reattachment (TOR) without excision of the bony fragment and (2) to determine the risk factors for postoperative radiological loss of reduction.
Methods
For this retrospective cohort study, consecutive patients with inferior pole patellar fracture between January 2010 and December 2017 were recruited. The patients were grouped according to their fixation method (TBW or TOR), and demographic data, clinical outcomes, and postoperative Insall–Salvati (IS) ratio were analyzed. Then, the patients were grouped according to radiological loss of reduction, the possible risk factors for loss of reduction were identified, and odds ratios were calculated.
Result
This study included 55 patients with inferior pole patellar fracture; 30 patients were treated using TBW and 25 were treated using TOR. Clinical failure occurred in two patients in the TBW group (7%) and three in the TOR group (12%). The rate of radiological loss of reduction was significant higher in the TOR group, whereas removal of implants was significantly more common in the TBW group. Patella baja was noted immediately after surgery in the TOR group, but the IS ratios of the two groups were similar after 3 months. Fracture displacement of more than 30 mm was the only independent risk factor for postoperative radiological loss of reduction.
Conclusion
For treating inferior pole patellar fracture, both TWB and TOR were effective and had a low clinical failure rate. In 60% of patients undergoing TBW fixation, however, additional surgery was required to remove the implants. Patella baja occurred immediately following TOR, but the patellar height was similar to that in the TBW group after 3 months. Surgeons should be aware of the high risk of postoperative radiological loss of reduction, especially when the fracture displacement is more than 30 mm.
Poor functional outcome can result from humeral greater tuberosity (GT) fracture if not treated appropriately. A two-screw construct is commonly used for the surgical treatment of such injury. ...However, loss of reduction is still a major concern after surgery. To improve the biomechanical strength of screw fixation in GT fractures, we made a simple modification of the two-screw construct by adding a cerclage wire to the two-screw construct. The purpose of this biomechanical study was to analyze the effect of this modification for the fixation of GT fractures.
Sixteen fresh-frozen human cadaveric shoulders were used in this study. The fracture models were arbitrarily assigned to one of two fixation methods. Group A (n = 8) was fixed with two threaded cancellous screws with washers. In group B (n = 8), all screws were set using methods identical to group A, with the addition of a cerclage wire. Horizontal traction was applied via a stainless steel cable fixed directly to the myotendinous junction of the supraspinatus muscle. Displacement of the fracture fixation under a pulling force of 100 N/200 N and loading force to construct failure were measured.
The mean displacements under 100 N and 200 N traction force were both significantly decreased in group B than in group A. (100 N: 1.06 ± 0.12 mm vs. 2.26 ± 0.24 mm, p < 0.001; 200 N: 2.21 ± 0.25 mm vs. 4.94 ± 0.30 mm, p < 0.001) Moreover, the failure load was significantly higher in group B compared with group A. (415 ± 52 N vs.335 ± 47 N, p = 0.01), CONCLUSIONS: The current biomechanical cadaveric study demonstrated that the two-screw fixation construct augmented with a cerclage wire has higher mechanical performance than the conventional two-screw configuration for the fixation of humeral GT fractures.
Retrospectively registered.
Artificial photosynthesis using semiconductors has been investigated for more than three decades for the purpose of transferring solar energy into chemical fuels. Numerous studies have revealed that ...the introduction of plasmonic materials into photochemical reaction can substantially enhance the photo response to the solar splitting of water. Until recently, few systematic studies have provided clear evidence concerning how plasmon excitation and which factor dominates the solar splitting of water in photovoltaic devices. This work demonstrates the effects of plasmons upon an Au nanostructure–ZnO nanorods array as a photoanode. Several strategies have been successfully adopted to reveal the mutually independent contributions of various plasmonic effects under solar irradiation. These have clarified that the coupling of hot electrons that are formed by plasmons and the electromagnetic field can effectively increase the probability of a photochemical reaction in the splitting of water. These findings support a new approach to investigating localized plasmon-induced effects and charge separation in photoelectrochemical processes, and solar water splitting was used herein as platform to explore mechanisms of enhancement of surface plasmon resonance.
The patient self-report section of the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASESp) is one of the most validated and reliable assessment tools. This study aimed ...to establish a validated Chinese version of ASESp (ASESp-CH).
A clinical prospective study was performed (ClinicalTrials.gov Identifier: NCT04755049; registered on 2021/02/11). Following the guidelines of forward-backward translation and cross-cultural adaptation, a Chinese version of ASESp was established. Patients older than 18 years with shoulder disorders were included. Patients who could not complete test-retest questionnaires within the interval of 7-30 days and patients who received interventions were excluded. Intraclass correlation (ICC) was calculated for test- retest reliability, whereas internal consistency was determined by Cronbach value. Construct validity was evaluated by comparing the corresponding domains between the ASESp-CH and a validated Chinese version of 36-Item Short Form Health Survey (SF-36).
A total of 86 patients were included with a mean test-retest interval of 12 ± 5.4 days. Test-retest reliability was excellent with an ICC of 0.94. Good internal consistency was found, with a Cronbach alpha of 0.86. Construct validity of the ASESp-CH questionnaire was good. The major domains of the ASESp-CH were significantly correlated with the respective domains in the SF-36 (p < 0.01), except for the domain of stability of ASESp-CH.
The Chinese version of ASESp questionnaire is a highly validated and reliable tool for shoulder disorder assessment.
The treatment of Hoffa fractures is challenging, for which the ideal fixation and approach are still controversial. Osteosynthesis with plate or screws fixation in different trajectories have been ...described in previous literature. The purpose of this study was to compare the biomechanical strength and stability of two types of screw trajectories used to stabilize displaced coronal fractures of the lateral femoral condyle.
Sixteen synthetic femurs (Sawbones Pacific Research Laboratories, Vashon, WA) were divided into two groups. A vertical osteotomy was performed to mimic a Letenneur type I Hoffa fracture. Group A (n = 8) was fixed with screw in anteroposterior direction (A-P) screws. Group B (n = 8) was fixed with crossed screws. Both groups were tested with a nondestructive axial compression aligned with the femur axis. After that, 10,000 cyclic loading tests were applied to the specimen with a force ranging between 200 to 600 N, and the interfragmental displacement was recorded, respectively, after 10, 100, 1000 and 10,000 cycles. Finally, a destructive axial compression test was applied until catastrophic failure.
There were no statistical between-group differences in regard to the average axial stiffness, interfragmental displacement, and ultimate failure load. The average axial stiffness of the A-P screw was comparable to that of the crossed screw (361 ± 113 N/mm vs. 379 ± 65 N/mm, p = 0.753). All specimens completed the entire cyclic loading test without catastrophic failure, and the interfragmental displacement after loading for 10,000 cycles was 1.36 ± 0.40 mm for the A-P screw and 1.29 ± 0.61 mm for the crossed screw, there were no statistical differences between the groups (p = 0.823). The average ultimate failure loads for the A-P and crossed screws were 1214 ± 127 N and 1109 ± 156 N, respectively (p = 0.172).
Based on our in vitro study, the crossed screws can provide comparable mechanical performance as traditional A-P screws in Hoffa fracture fixation. Considering the screws trajectories are commonly determined by the choice of surgical approach, the current study provides support from a biomechanical perspective for the application of crossed screws in direct lateral approach.
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