ON-OFF Control of Marangoni Self-propulsion via A Supra-amphiphile Fuel and Switch.

Marangoni self-propulsion refers to motions of liquid or solids driven by a surface tension gradient, and has applications in soft robots/devices, cargo delivery, self-assembly etc. However, two problems remain to be addressed for motion control (e.g., ON-OFF) with conventional surfactants as Marangoni fuel: (1) limited motion lifetime due to saturated interfacial adsorption of surfactants; (2) in- situ motion stop is difficult once Marangoni flows are triggered. Instead of covalent surfactants, supra-amphiphiles with hydrophilic and hydrophobic parts linked noncovalently, hold promise to solve these problems owing to its dynamic and reversible surface activity responsively. Here, we propose a new concept of 'supra-amphiphile fuel and switch' based on the facile synthesis of disodium-4-azobenzene-amino-1,3-benzenedisulfonate (DABS) linked by a Schiff base, which has amphiphilicity for self-propulsion, hydrolyzes timely to avoid saturated adsorption and provides pH-responsive control over ON-OFF motion. The self-propulsion lifetime is extended by 50-fold with DABS and motion control is achieved. The mechanism is revealed with coupled interface chemistry involving two competitive processes of interfacial adsorption and hydrolysis of DABS based on both experiments and simulation. The concept of 'supra-amphiphile fuel and switch' provides an active solution to prolong and control Marangoni self-propulsive devices for the advance of intelligent material systems.

Synergistic Development of Natural Rubber/Butyl Rubber Composites for Improved Interfacial Bonding and Enhanced Shock-Absorbing Capabilities.

Shock-absorbing materials play a vital role in various industrial sectors, including construction and transportation. Among these materials, natural rubber (NR) stands out due to its exceptional elastic and mechanical properties, coupled with its robust crack resistance. Nevertheless, with the rising demand for enhanced damping capacities, there is a need to further optimize the damping performance of NR. One direct approach is to blend it with high-damping rubber. Butyl rubber (IIR) is a prominent member of the high-damping rubber category. Integrating IIR effectively with the NR, however, presents challenges. These challenges arise from IIR's inherent characteristics, such as its low unsaturation, slower vulcanization rate, and restricted compatibility with NR. Addressing these challenges, our study employed isoprene and isobutene to synthesize a variant of butyl rubber with a higher degree of unsaturation-achieving an unsaturation level between 4 and 6 mol %. Notably, this heightened unsaturation significantly expedited the curing time of IIR and facilitated the concurrent vulcanization of both IIR and NR. Utilizing atomic force microscopy, we observed that the introduction of unsaturated double bonds ameliorated the compatibility between NR and IIR, leading to an interfacial region extending up to 1000 nm. Our tests using a dynamic mechanical analyzer and rubber processing analyzer demonstrated the material's damping temperature range. Furthermore, there was a noticeable rise in the loss factor (tan δ) at ambient temperature, which remains over 0.1 across both a frequency window of 0.2 to 5 Hz and a strain spectrum of 10 to 200%. This tan δ enhancement ensured the potential of these rubber composites for shock-absorbing applications.

Hemophagocytic lymphohistiocytosis associated with brucellosis.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immune disorder categorized as familial HLH or secondary HLH. Our case report describes a 63-year-old woman with epilepsy whose clinical signs were unremitting fever and altered consciousness. Primary abnormalities consisted of fever, splenomegaly, cytopenia, hypertriglyceridemia, hyperferritinemia and hemophagocytosis in the bone marrow. Results of blood next generation sequencing and blood culture confirmed Brucella infection. This report illustrates a sHLH case caused by Brucella melitensis infection. Here, we review the classification, clinical features, diagnostic methods, treatment regimens, differential diagnosis, and prognosis of HLH and brucellosis.

Genetic variants, haplotype determination, and function of novel alleles of CYP2B6 in a Han Chinese population.

Amino acid variants in protein may result in deleterious effects on enzymatic activity. In this study we investigate the DNA variants on activity of CYP2B6 gene in a Chinese Han population for potential use in precision medicine. All exons in CYP2B6 gene from 1483 Chinese Han adults (Zhejiang province) were sequenced using Sanger sequencing. The effects of nonsynonymous variants on recombinant protein catalytic activity were investigated in vitro with Sf12 system. The haplotype of novel nonsynonymous variants with other single nucleotide variants in the same allele was determined using Nanopore sequencing. Of 38 alleles listed on the Pharmacogene Variation Consortium, we detected 7 previously reported alleles and 18 novel variants, of which 11 nonsynonymous variants showed lower catalytic activity (0.00-0.60) on bupropion compared to CYP2B6*1. Further, these 11 novel star-alleles (CYP2B6*39-49) were assigned by the Pharmacogene Variation Consortium, which may be valuable for pharmacogenetic research and personalized medicine.

Are extra locking bolts or fibular plating more important in extreme nailing of distal tibia fractures? A cadaveric biomechanical analysis.

OBJECTIVES: In far-distal extra-articular tibia fracture "extreme" nailing, debate surrounds the relative biomechanical performance of plating the fibula compared with extra distal interlocks. This study aimed to evaluate several constructs for extreme nailing including one interlock (one medial-lateral interlock), one interlock + plate (one medial-lateral interlock with lateral fibula compression plating), and two interlocks (one medial-lateral interlock and one anterior-posterior interlock). METHODS: Fifteen pairs of fresh cadaver legs were instrumented with a tibial nail to the physeal scar. A 1 cm segment of bone was resected from the distal tibia 3.5 cm from the joint and an oblique osteotomy was made in the distal fibula. We loaded specimens with three different distal fixation constructs (one interlock, one interlock + plate, and two interlocks) through 10,000 cycles form 100N-700 N of axial loading. Load to failure (Newtons), angulation and displacement were also measured. RESULTS: Mean load to failure was 2092 N (one interlock), 1917 N (one interlock + plate), and 2545 N (two interlocks). Linear mixed effects modeling demonstrated that two interlocks had a load to failure 578 N higher than one interlock alone (95 % CI, 74N-1082 N; P = 0.02), but demonstrated no significant difference between one interlock and one interlock + plate. No statistically significant difference in rates or timing of displacement >2 mm or angulation >10° were demonstrated. CONCLUSIONS: When nailing far-distal extra-articular tibia and fibula fractures, adding a second interlock provides more stability than adding a fibular plate. Distal fibula plating may have minimal biomechanical effect in extreme nailing.

Albumin-to-D-dimer ratios: A novel prognostic factor for evaluating first-line chemotherapy efficacy in advanced lung adenocarcinoma patients.

The prognosis of advanced lung adenocarcinoma (LUAD) remains unfavorable, with chemotherapy constituting a primary treatment modality. Discerning the efficacy of chemotherapy for advanced LUAD is imperative. Prior investigations have demonstrated the prognostic value of albumin and D-dimer individually for malignancies; however, the predictive capacity of albumin-to-D-dimer ratios (ADR) for advanced LUAD subjected to first-line platinum-based chemotherapy remains unexplored. A cohort of 313 patients with advanced LUAD was retrospectively examined in this study, spanning from January 2017 to January 2021. ADR threshold values were ascertained via receiver operating characteristic analysis, followed by the evaluation of the association between pretreatment ADR and clinicopathological characteristics, disease control rate (DCR), and overall response rate (ORR) pertinent to first-line chemotherapy. Prognostic factors for progression-free survival (PFS) were determined employing Cox univariate and multivariate analyses. Subsequently, survival data were illustrated utilizing the Kaplan-Meier method and scrutinized through the log-rank test across the entire and subgroup populations. ADR demonstrated a superior area under the curve (AUC) value relative to albumin and D-dimer individually and exhibited enhanced prognostic predictive capability compared to albumin-to-fibrinogen ratios (AFR) for advanced LUAD (AUC: 0.805 vs. 0.640, DeLong test: p<0.001). ADR yielded a cut-off value of 16.608. A greater proportion of non-smokers was observed within the high-ADR group (ADR>16.608) compared to the low-ADR group (ADR≤16.608). Patients in the high-ADR group displayed elevated BMI and Na+ levels and reduced neutrophil count, monocyte count, globulin, and alkaline phosphatase (all p<0.05). Notably, the high-ADR group exhibited heightened DCR (96.7% vs. 89.2%, p=0.008) and ORR rates (70.1% vs. 51.0%, p=0.001) relative to the low-ADR group. Multivariate analysis outcomes indicated that high ADR constituted an independent risk factor for PFS (hazard ratio: 0.24, p<0.001). Furthermore, patients in the high-ADR cohort displayed a significantly prolonged median PFS (254 vs. 142 days, p<0.0001) compared to their low-ADR counterparts. In subpopulations exhibiting favorable implications for PFS, as determined by multivariate analysis, high-ADR patients consistently demonstrated extended PFS durations relative to the low-ADR group (all p<0.0001). Collectively, our findings suggest that ADR constitutes a novel and promising prognostic indicator for advanced LUAD patients, surpassing the accuracy of albumin and D-dimer individually and AFR. ADR thus serves as a potent instrument for assessing treatment effects and PFS in advanced LUAD patients undergoing first-line chemotherapy.

Manipulating the Properties of Polymer Vitrimer Nanocomposites by Designing Dual Dynamic Covalent Bonds.

Polymer vitrimer is a novel material that contains dynamic covalent bonds (DCBs) allowing it to combine the desirable characteristics of both thermoplastics and thermosets. Similar to the traditional polymer nanocomposites, introducing nanoparticles into polymer vitrimer is also an effective strategy to further enhance its properties. However, a comprehensive understanding of matrix and interfacial bond exchange reactions (BERs) to tailor the properties of polymer vitrimer nanocomposites (PVNs) is still lacking. Herein, we utilized coarse-grained molecular dynamics simulations to investigate model PVNs in which there are two different kinds of DCBs in the vitrimer matrix and at the interface. Our results show that the normalized bond autocorrelation function (Csw) confirms the independence of BERs in the vitrimer matrix and in the interface. By varying the bond swap energy barrier (ΔEsw) in the matrix ΔEswmat or in the interface ΔEswint, or in both ΔEswall, a maximum mechanical property is observed at the moderate value of ΔEswmat, ΔEswint, orΔEswall. Meanwhile, the effect of ΔEsw on the stress relaxation and the bond orientation as a function of the time under a fixed strain is well probed, which both decay more slowly at greater ΔEsw. We simulated the tension-recovery curve to examine the effect of ΔEsw on the hysteresis loss and permanent deformation of PVNs, finding an optimal value to achieve its minimum energy dissipation and maximum recovery ratio. Lastly, we investigated the efficiency of self-healing by building and removing walls from the system. Interestingly, a maximum self-healing efficiency of the stress-strain behavior is observed at moderate ΔEsw. Overall, this study provides valuable insights into the relationship between the structure and properties of PVNs, offering implications for the manipulation of their mechanical properties and enhancement of their self-healing capabilities.

Synthesis of Mechanically Robust Very High Molecular Weight Polyisoprene Particle Brushes by Atom Transfer Radical Polymerization.

Linear polyisoprene (PI) and SiO2-g-PI particle brushes were synthesized by both conventional and activators regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP). The morphology and solution state study on the particle brushes by transmission electron microscopy (TEM) and dynamic light scattering (DLS) confirmed the successful grafting of PI ligands on the silica surface. The presence of nanoparticle clusters suggests low grafting density (associated with the limited initiation efficiency of ARGET for PI). Nevertheless, particle brushes with very high molecular weights, Mn > 300,000, were prepared, which significantly improved the dispersion of silica nanoparticles and also contributed to excellent mechanical performance. The reinforcing effects of SiO2 nanofillers and very high molecular weight PI ligands were investigated by dynamic mechanical analysis (DMA) as well as computational simulation for the cured linear PI homopolymer/SiO2-g-PI particle brush bulk films.

Flexible Conformally Bioadhesive MXene Hydrogel Electronics for Machine Learning-Facilitated Human-Interactive Sensing.

Wearable epidermic electronics assembled from conductive hydrogels are attracting various research attention for their seamless integration with human body for conformally real-time health monitoring, clinical diagnostics and medical treatment, and human-interactive sensing. Nevertheless, it remains a tremendous challenge to simultaneously achieve conformally bioadhesive epidermic electronics with remarkable self-adhesiveness, reliable ultraviolet (UV) protection ability, and admirable sensing performance for high-fidelity epidermal electrophysiological signals monitoring, along with timely photothermal therapeutic performances after medical diagnostic sensing, as well as efficient antibacterial activity and reliable hemostatic effect for potential medical therapy. Herein, a conformally bioadhesive hydrogel-based epidermic sensor, featuring superior self-adhesiveness and excellent UV-protection performance, is developed by dexterously assembling conducting MXene nanosheets network with biological hydrogel polymer network for conformally stably attaching onto human skin for high-quality recording of various epidermal electrophysiological signals with high signal-to-noise ratios (SNR) and low interfacial impedance for intelligent medical diagnosis and smart human-machine interface. Moreover, a smart sign language gesture recognition platform based on collected electromyogram (EMG) signals is designed for hassle-free communication with hearing-impaired people with the help of advanced machine learning algorithms. Meanwhile, the bioadhesive MXene hydrogel possesses reliable antibacterial capability, excellent biocompatibility, and effective hemostasis properties for promising bacterial-infected wound bleeding.

The relationship between toxic air pollution, health expenditure, and economic growth in the European Union: fresh evidence from the PMG-ARDL model.

Air pollution is a danger to economies throughout the European Union. Industry, population expansion, a building boom owing to housing and infrastructure development, increasing vehicle traffic, crowded streets, a lack of availability of clean fuel, and ineffective control programs are the primary causes. Toxic air is a double-edged sword for a country's health since it affects just a tiny fraction of Europe's population. The financial burden and healthcare expenses for people rise when health expenditures rise. The present research looks at how dangerous air levels, healthcare costs, and the expansion of the European Union's economy are all connected. The findings are based on data collected over 29 years and account for the abovementioned variables. The results of the unit root test have the significant probability values of all variables: health expenditures (HE), gross domestic product (GDP), nitrous oxides (NOX), and carbon dioxides (CO2) emissions at both level and first difference. We used the Johansen, Kao, and Pedroni cointegration tests to test the null hypothesis of no cointegration to see that sample variables had a long-term association. The PMG-ARDL test was used to get these findings. The results confirmed the significant probability values of dependent variables in long- and short-run results that GDP has a positive and significant effect on health expenditure, while NOX and CO2 emissions have a negative and significant impact on (HE), in the European Union. To verify the results, we applied the robustness test, fully modified OLS (FMOLD), and dynamic OLS (DOLS); the robustness test results validated the PMG-ARDL test results. Environmental pollution (CO2, NOX) has a significant and negative impact on healthcare expenditures and a significant effect on GDP (HE) in the EU region. The findings of this research have implications for a wide range of parties, including those who would examine the link between factors in a study meant to improve air quality, distribute health resources, or develop strategies for economic development.

Rational Design of F-Modified Polyester Electrolytes for Sustainable All-Solid-State Lithium Metal Batteries.

Solid polymer electrolytes (SPEs) are one of the most practical candidates for solid-state batteries owing to their high flexibility and low production cost, but their application is limited by low Li+ conductivity and a narrow electrochemical window. To improve performance, it is necessary to reveal the structure-property relationship of SPEs. Here, 23 fluorinated linear polyesters were prepared by editing the coordination units, flexible linkage segments, and interface passivating groups. Besides the traditionally demonstrated coordinating capability and flexibility of polymer chains, the molecular asymmetry and resulting interchain aggregation are observed critical for Li+ conductivity. By tailoring the molecular asymmetry and coordination ability of polyesters, the Li+ conductivity can be raised by 10 times. Among these polyesters, solvent-free poly(pentanediol adipate) delivers the highest room-temperature Li+ conductivity of 0.59 × 10-4 S cm-1. The chelating coordination of oxalate and Li+ leads to an electron delocalization of alkoxy oxygen, enhancing the antioxidation capability of SPEs. To lower the cost, high-value LiTFSI in SPEs is recycled at 90%, and polyesters can be regenerated at 86%. This work elucidates the structure-property relationship of polyester-based SPEs, displays the design principles of SPEs, and provides a way for the development of sustainable solid-state batteries.

A Periosteum-Bioinspired Electrospun Janus Membrane with Antibacterial and Osteogenic Dual Function.

For a guided bone regeneration membrane, it is critical to possess osteogenic capability while inhibiting infection caused by bacteria. Inspired by the bilayer structure of the native periosteum, an electrospun Janus membrane with osteogenic and antibacterial dual-function is fabricated for guided bone regeneration. Hydrophilic moxifloxacin (MXF) and hydrophobic icariin (ICA) are loaded in the nanofibers made of a mixture of polycaprolactone and gelatin at the top and bottom layers, respectively, leading to the opposing hydrophilic/hydrophobic properties of the bilayer Janus membranes. The as-obtained Janus membrane exhibits excellent physical properties (tensile strength > 6.0 MPa) and robust biocompatibility, indicating the immense potential as a suitable replacement for the native periosteum. The membrane has a superior surface morphology and outstanding degradation performance in vitro. Besides, the rapid release of MXF and the slow release of ICA can meet the different needs of drug release rates. Only ≈30% ICA is released from the as-obtained Janus membrane after 21 d while almost 80% MXF is released. Mimicking the bilayer structure of the native periosteum, the electrospun Janus membrane containing ICA and MXF exhibits excellent comprehensive properties, which provides a promising strategy for preparing multifunctional scaffolds for tissue engineering.

In-situ self-crosslinking strategy for super-tough polylactic acid/ bio-based polyurethane blends.

As a bio-based degradable plastic, polylactic acid (PLA) is highly commercialized, but its inherent brittleness limits its widespread use. In-situ polymerization techniques are effective in improving the toughness of PLA. However, the enhancement of the toughening effect in polyurethanes (PUs) through in-situ self-crosslinking still requires improvement and heavily relies on petroleum-derived feedstocks in certain approaches. In this paper, 1,3-polypropanediol (PO3G) of bio-based origin rather than conventional polyols like polyethylene glycol (PEG) and poly propylene glycol (PPG) was used. PLA/PO3G-PU blends were prepared via an in-situ self-crosslinking strategy. With a notch impact and tensile strength of 55.95 kJ/m2 and 47.77 MPa (a retention rate of 68.9 % compared with pure PLA), respectively, PLA/PO3G-PU blends achieved a better balance between stiffness and toughness. This work provides a new option for PLA to achieve a stiffness-toughness balance and get rid of dependence on petrochemical resources.

Biomechanical evaluation of different oblique lumbar interbody fusion constructs: a finite element analysis.

BACKGROUND: Finite element analysis (FEA) was performed to investigate the biomechanical differences between different adjunct fixation methods for oblique lumbar interbody fusion (OLIF) and to further analyze its effect on adjacent segmental degeneration. METHODS: We built a single-segment (Si-segment) finite element model (FEM) for L4-5 and a double-segment (Do-segment) FEM for L3-5. Each complete FEM was supplemented and modified, and both developed two surgical models of OLIF with assisted internal fixation. They were OLIF with posterior bilateral percutaneous pedicle screw (TINA system) fixation (OLIF + BPS) and OLIF with lateral plate system (OLIF + LPS). The range of motion (ROM) and displacement of the vertebral body, cage stress, adjacent segment disc stress, and spinal ligament tension were recorded for the four models during flexion/extension, right/left bending, and right/left rotation by applying follower load. RESULTS: For the BPS and LPS systems in the six postures of flexion, extension, right/left bending, and right/left rotation, the ROM of L4 in the Si-segment FEM were 0.32°/1.83°, 0.33°/1.34°, 0.23°/0.47°, 0.24°/0.45°, 0.33°/0.79°, and 0.34°/0.62°; the ROM of L4 in the Do-segment FEM were 0.39°/2.00°, 0.37°/1.38°, 0.23°/0.47°, 0.21°/0.44°, 0.33°/0.57°, and 0.31°/0.62°, and the ROM of L3 in the Do-segment FEM were 6.03°/7.31°, 2.52°/3.50°, 4.21°/4.38°, 4.21°/4.42°, 2.09°/2.32°, and 2.07°/2.43°. BPS system had less vertebral displacement, less cage maximum stress, and less spinal ligament tension in Si/Do-segment FEM relative to the LPS system. BPS system had a smaller upper adjacent vertebral ROM, greater intervertebral disc stress in terms of left and right bending as well as left and right rotation compared to the LPS system in the L3-4 of the Do-segment FEM. There was little biomechanical difference between the same fixation system in the Si/Do-segment FEM. CONCLUSIONS: Our finite element analysis showed that compared to OLIF + LPS, OLIF + BPS (TINA) is more effective in reducing interbody stress and spinal ligament tension, and it better maintains the stability of the target segment and provides a better fusion environment to resist cage subsidence. However, OLIF + BPS (TINA) may be more likely to cause adjacent segment degeneration than OLIF + LPS.

Molecular Dynamics Simulations on Spike Protein Mutants Binding with Human ß Defensin Type 2.

Human ß defensin type 2 (hBD-2), a cationic cysteine-rich peptide secreted from the human innate immune system, can bind Spike-RBD at the same site as receptor ACE2, thus blocking viral entry into ACE2-expressing cells. In order to find out the impact of CoV-2 mutations on hBD-2's antiviral activity, it is important to investigate the binding and interaction of hBD-2 with RBD mutants. All-atom molecular dynamics simulations were conducted on typical RBD mutants, including N501Y, E484K, P479S, T478I, S477N, N439K, K417N, and N501Y-E484K-K417N, binding with hBD-2. Starting from the stable binding structure of hBD-2 and wt-RBD and ClusPro and HADDOCK docking-predicted initial structures, the RBD variants bound with hBD-2 simulations were set up, and NAMD simulations were conducted. Based on the structure and dynamics analysis, it was found that most RBD variants can still form a similar number of hydrogen bonds with hBD-2, in addition to having a similar-sized buried surface area (BSA) and a similar binding interface to the RBD wildtype. However, the RBD triple mutant formed a less stable binding structure with hBD-2 than other variants. Additionally, the free energy perturbation (FEP) method was applied to calculate the contribution of key mutant residues to the binding and the free energy change caused by the mutations. The result shows that N439K, K417N, and the trimutation increase the binding free energy of RBD with hBD-2; thus, RBD should bind less stably with hBD-2. E484K decreases the binding free energy, thus it should bind more stably with hBD-2, while N501Y, S477N, T478I, and P479S almost do not change the binding free energy with hBD-2. The MM-GBSA method predicted the binding interaction energy which shows that the trimutant should be able to escape the binding with hBD-2 but N501Y should not. The result can provide insight into understanding the functional mechanism of hBD-2 combating SARS-CoV-2 mutants.

Trends and Future Research in Skeletal Muscle Tissue Engineering in the Past Decade (2012-2022).

To learn about advances in skeletal muscle tissue engineering (SMTE) in recent years, we used VOSviewer and Citespace software to quantitatively analyze and visualize relevant literature in the Web of Science database during the period 2012-2022. By mapping high-frequency keyword relationship networks, keyword time zones, and journal article cocitations, we clarified the areas of great interest, evolutionary paths, and developmental trends in research on SMTE. We conducted an in-depth analysis of highly cited and representative articles at various stages to summarize the mainstream research areas of great interest in SMTE and discussed the future development and challenges in this field, intending to provide a reference for the clinical treatment of skeletal muscle injury repair. We found that a collaborative network of authors has formed in this field; the journals publishing SMTE articles belong to the fields of biomaterials and tissue engineering, and open-access journals have played a key role in the promotion of the development of SMTE; and in the past decade, there has been rapid progress in SMTE research in terms of both depth and breadth. Impact statement Compared with the literature review method, bibliometrics can provide a comprehensive knowledge of a knowledge area based on a huge amount of literature. In this article, based on the Web of Science database, CiteSpace, and Vosviewer visualization tools were used to measure and analyze the literature reports in the field of skeletal muscle tissue engineering (SMTE). The research hotspots and cutting-edge information on SMTE were mined in terms of the number of publications, the number of citations, the keywords, the authors, and the publishing institutions to understand the current status of the research on SMTE in the world, to provide a reference for related researchers, engineering research in the field of SMTE, to comprehensively understand the current status of global research in the field of SMTE, and to provide a reference for related researchers.

Biomechanical Comparison of Four- versus Six-Strand Transosseous Suture Repair for Patellar Tendon Rupture.

BACKGROUND: Surgical repair is indicated for patellar tendon ruptures that result in loss of knee extensor mechanism function. However, biomechanical studies report conflicting results when comparing transosseous suture versus suture anchor repair techniques. This discrepancy may be due to inconsistencies in experimental design as these studies use various numbers of suture strands. Therefore, the main objective of this study is to compare the ultimate load of four- versus six-strand transosseous suture repair. Secondary objectives are to compare gap formation after cyclical loading and mode of failure. METHODS: Six pairs of fresh-frozen cadaveric specimen were randomly allocated to either four- or six-strand transosseous suture repair. Specimen underwent preconditioning cyclical loading and then load to failure. RESULTS: The six-strand repair had a significantly higher maximum load to failure compared with the four-strand repair (mean difference = 319.3 N [57.9%], p = 0.03). There was no significant difference in gap length after cyclical loading or at max load. There were no significant differences in mode of failure. CONCLUSION: Utilizing a six-stand transosseous patella tendon repair construct with one additional suture increases overall construct strength by over 50% compared with a four-strand construct.