Benchmarking pH-field coupled microkinetic modeling against oxygen reduction in large-scale Fe-azaphthalocyanine catalysts.

Molecular metal-nitrogen-carbon (M-N-C) catalysts with well-defined structures and metal-coordination environments exhibit distinct structural properties and excellent electrocatalytic performance, notably in the oxygen reduction reaction (ORR) for fuel cells. Metal-doped azaphthalocyanine (AzPc) catalysts, a variant of molecular M-N-Cs, can be structured with unique long stretching functional groups, which make them have a geometry far from a two-dimensional geometry when loaded onto a carbon substrate, similar to a "dancer" on a stage, and this significantly affects their ORR efficiency at different pH levels. However, linking structural properties to performance is challenging, requiring comprehensive microkinetic modeling, substantial computational resources, and a combination of theoretical and experimental validation. Herein, we conducted pH-dependent microkinetic modeling based upon ab initio calculations and electric field-pH coupled simulations to analyze the pH-dependent ORR performance of carbon-supported Fe-AzPcs with varying surrounding functional groups. In particular, this study incorporates large molecular structures with complex long-chain "dancing patterns", each featuring >650 atoms, to analyze their performance in the ORR. Comparison with experimental ORR data shows that pH-field coupled microkinetic modeling closely matches the observed ORR efficiency at various pH levels in Fe-AzPc catalysts. Our results also indicate that assessing charge transfer at the Fe-site, where the Fe atom typically loses around 1.3 electrons, could be a practical approach for screening appropriate surrounding functional groups for the ORR. This study provides a direct benchmarking analysis for the microkinetic model to identify effective M-N-C catalysts for the ORR under various pH conditions.

Bone-patellar tendon-bone autograft is associated with a higher rate of return to preinjury levels of performance in high-level athletes than anterior cruciate ligament reconstruction using hamstring autograft.

PURPOSE: Return to preinjury levels of performance (RTP) is the main goal after anterior cruciate ligament reconstruction (ACL-R) for athletes when ACL graft rupture is a career-threatening event. The purpose of this study was to elucidate the associated factors for RTP and subsequent ACL injury after ACL-R using bone-patellar tendon-bone (BPTB) or hamstring (HT) autograft in high-level athletes with a minimum postoperative follow-up of 24 months. METHODS: This retrospective study included 157 patients who had preinjury Tegner activity level of 9 and underwent primary ACL-R using BPTB (average age, 16.9 years; 35 males and 36 females) or HT (average age, 17.2 years; 49 males and 37 females). The mean follow-ups were 33.6 months in BPTB and 44.5 months in HT, respectively. The data were obtained based on routine clinical follow-ups and telephone interviews performed by the surgeon. Multivariate logistic regression analysis was conducted to determine the association of patient variables with RTP and subsequent ACL injury. RESULTS: Ninety-nine patients (63.1%) were able to RTP. The rate of RTP in BPTB (74.6%) was significantly higher than that of HT (53.5%) (p < 0.05). The overall average timing of RTP after ACL-R was 10.0 months while that was significantly earlier in BPTB (9.7 months) than in HT (10.5 months) (p < 0.05). Twenty-three (14.6%) and 21 patients (13.4%) had ACL graft ruptures and ACL injuries in the contralateral knees, respectively. Multivariate analyses showed that BPTB (odds ratio [OR], 2.590; 95% confidence interval [CI], 1.300-5.160; p = 0.007) was associated with a higher potential for RTP after ACL-R. The incidence of ACL graft rupture after ACL-R decreased with BPTB (OR, 0.861; 95% CI, 0.770-0.962; p = 0.009). CONCLUSIONS: The use of BPTB autograft was associated with a higher rate of RTP and a lower incidence of ACL graft rupture compared to ACL-R using HT autograft. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Effect of inside-out meniscal repair on meniscal dimension in meniscal tear patients.

Background: It remains controversial whether meniscal repair causes meniscal extrusion. This study aimed to investigate the effect of inside-out meniscal repair on meniscal dimensions in patients with meniscal tear of the mid-body-posterior horn. Methods: This retrospective study included 75 patients who underwent meniscal repair followed by MRI within 2 weeks after surgery between 2020 and 2022. Patients with a discoid lateral meniscus, pull-out repair, concomitant osteotomy, all-inside repair only, and revision surgery were excluded. Thirty-three meniscal tear treated using an inside-out arthroscopic repair technique were included in the lateral meniscus (LM, n = 19) and medial meniscus (MM, n = 14) tear groups. Thirty-six participants with intact meniscus were included as controls. Meniscal extrusion and posterior shift were measured on coronal and sagittal MRI pre-operatively and within 2 weeks postoperatively. Results: Preoperative coronal extrusion was significantly greater in the LM tear group than in the control group (P = 0.001). Coronal extrusion and posterior shift were significantly smaller postoperatively than preoperatively in the LM tear group (P < 0.001 and, P = 0.008, respectively). Pre- and postoperative coronal extrusion in the MM tear group were not significantly different (P = 0.291). Postoperative coronal extrusion in both LM and MM tear groups were not significantly correlated with the number of sutures required for repair (LM: P = 0.765, R = -0.076, MM: P = 0.1, R = 0.497). Conclusions: The torn meniscus of the mid-body - posterior horn before surgery was extruded and shifted posteriorly in both LM and MM tears, and repair using an inside-out arthroscopic technique was effective in reducing meniscal extrusion and posteriors shift in the LM tear immediately after surgery.

TusDCB, a sulfur transferase complex involved in tRNA modification, contributes to UPEC pathogenicity.

tRNA modifications play a crucial role in ensuring accurate codon recognition and optimizing translation levels. While the significance of these modifications in eukaryotic cells for maintaining cellular homeostasis and physiological functions is well-established, their physiological roles in bacterial cells, particularly in pathogenesis, remain relatively unexplored. The TusDCB protein complex, conserved in γ-proteobacteria like Escherichia coli, is involved in sulfur modification of specific tRNAs. This study focused on the role of TusDCB in the virulence of uropathogenic E. coli (UPEC), a bacterium causing urinary tract infections. The findings indicate that TusDCB is essential for optimal production of UPEC's virulence factors, including type 1 fimbriae and flagellum, impacting the bacterium's ability to aggregate in bladder epithelial cells. Deletion of tusDCB resulted in decreased virulence against urinary tract infection mice. Moreover, mutant TusDCB lacking sulfur transfer activity and tusE- and mnmA mutants revealed the indispensability of TusDCB's sulfur transfer activity for UPEC pathogenicity. The study extends its relevance to highly pathogenic, multidrug-resistant strains, where tusDCB deletion reduced virulence-associated bacterial aggregation. These insights not only deepen our understanding of the interplay between tRNA sulfur modification and bacterial pathogenesis but also highlight TusDCB as a potential therapeutic target against UPEC strains resistant to conventional antimicrobial agents.

Photoelectron Holographic Study for Atomic Site Occupancy for Si Dopants in Si-Doped κ-Ga2O3(001).

We investigated atomic site occupancy for the Si dopant in Si-doped κ-Ga2O3(001) using photoelectron spectroscopy (PES) and photoelectron holography (PEH). From PES and PEH, we found that the Si dopant had one chemical state, and three types of inequivalent Si substitutional sites (SiGa) were formed. The ratios for the inequivalent tetrahedral, pentahedral, and octahedral SiGa sites were estimated to be 55.0%, 28.1%, and 16.9%, respectively. Higher (lower) ratios for the three inequivalent SiGa sites may come from a lower (higher) formation energy. The Tetra (Octa) SiGa site has the highest (lowest) ratio of the three SiGa sites since it has the lowest (highest) formation energy. We suggest that the tetrahedral SiGa site is due to the active dopant site, whereas the pentahedral and octahedral SiGa sites can be attributed to the inactive dopant sites for Si-doped κ-Ga2O3(001).

Identifying Stable Electrocatalysts Initialized by Data Mining: Sb2 WO6 for Oxygen Reduction.

Data mining from computational materials database has become a popular strategy to identify unexplored catalysts. Herein, the opportunities and challenges of this strategy are analyzed by investigating a discrepancy between data mining and experiments in identifying low-cost metal oxide (MO) electrocatalysts. Based on a search engine capable of identifying stable MOs at the pH and potentials of interest, a series of MO electrocatalysts is identified as potential candidates for various reactions. Sb2 WO6 attracted the attention among the identified stable MOs in acid. Based on the aqueous stability diagram, Sb2 WO6 is stable under oxygen reduction reaction (ORR) in acidic media but rather unstable under high-pH ORR conditions. However, this contradicts to the subsequent experimental observation in alkaline ORR conditions. Based on the post-catalysis characterizations, surface state analysis, and an advanced pH-field coupled microkinetic modeling, it is found that the Sb2 WO6 surface will undergo electrochemical passivation under ORR potentials and form a stable and 4e-ORR active surface. The results presented here suggest that though data mining is promising for exploring electrocatalysts, a refined strategy needs to be further developed by considering the electrochemistry-induced surface stability and activity.

Age-based comparison of meniscal dimensions between an asymptomatic complete discoid lateral meniscus and normal meniscus: MRI evaluation.

INTRODUCTION: This study aimed to evaluate the meniscal size of asymptomatic discoid lateral meniscus (DLM) and compare it with that of normal lateral meniscus (LM) and to compare changes in meniscal dimensions with age among patients with asymptomatic DLM and those with normal LM using magnetic resonance imaging (MRI). MATERIALS AND METHODS: We retrospectively reviewed the medical records, including MRI data, of patients with asymptomatic DLM (DLM group) or normal LM (control group). Width and extrusion of both DLM and normal LM and tibial length were measured and compared using mid-coronal and mid-sagittal MR images. Meniscal size and sagittal and coronal meniscal ratio according to age, as well as differences between DLM and normal menisci, were also evaluated. RESULTS: Thirty-four knees were included in the DLM group, whereas the control group comprised of 50 patients. The DLM group showed significantly less meniscal extrusion, greater coronal width, posterior capsule distance, sagittal meniscal length, and sagittal meniscal ratio than the control group (DLM: 0.1 ± 0.3 mm, 23.3 ± 2.2 mm, 5.4 ± 2.4 mm, 25.1 ± 2.8 mm, 61 ± 6%, and control: 0.4 ± 0.4 mm, 9.5 ± 2.3 mm, 2.5 ± 1.2 mm, 30.2 ± 2.6 mm, 71 ± 4%, respectively). The coronal meniscal ratio decreased with age in both the control (p = 0.001) and DLM (p = 0.037) groups. The sagittal meniscal ratio (p = 0.001) and minimum height (p = 0.04) decreased and the anterior capsule distance (p = 0.035), posterior capsule distance (p = 0.026), and entire sagittal length (p = 0.005) increased with age in the DLM group, while the distance between the meniscal inner margins (p = 0.019) increased with age in the control group. CONCLUSIONS: The meniscal ratio in the sagittal plane of the DLM group was significantly lower than that of the control group. The sagittal meniscal ratio of asymptomatic DLM decreased with age, indicating that the size of asymptomatic DLM does not change with age. LEVEL OF EVIDENCE: III: Retrospective comparative study.

Quadriceps Tendon With Bone Autograft Has Better Stability and Magnetic Resonance Imaging Maturation Than Hamstring Tendon Autograft After Anterior Cruciate Ligament Reconstruction in Patients With Knee Hyperextension.

PURPOSE: To compare the clinical outcomes of anterior cruciate ligament (ACL) reconstruction between methods using quadriceps tendon with bone (QTB) and hamstring tendon (HT) in patients with hyperextension of the knee. METHODS: The medical records of patients with knee hyperextension greater than 8° who underwent arthroscopic ACL reconstruction between October 2010 and October 2020 with follow-up for at least 2 years (median, 3 years; interquartile range [IQR], 2.0-4.6 years) were retrospectively reviewed. Side-to-side difference in anterior translation, pivot-shift test grade, Lysholm score, and graft intensity using the Howell grade on magnetic resonance imaging at final follow-up were compared between the QTB and HT groups. RESULTS: The HT and QTB groups consisted of 42 patients and 21 patients, respectively. The overall mean age was 21.5 years (range, 14-48 years), and the median Tegner Activity Scale score was 6 (range, 3-9). Postoperatively, the median side-to-side difference in anterior translation was 1.75 mm (IQR, 1-3 mm) in the HT group and 1.0 mm (IQR, 0-1.75 mm) in the QTB group (P = .01). Pivot-shift testing showed grade 0 in 74.7%, grade 1 in 18.7%, and grade 2 in 6.6% of patients in the HT group and grade 0 in 85.7% and grade 1 in 14.3% of those in the QTB group (P = .03). The median postoperative Lysholm score was 99 in both groups. Graft signal intensity showed a significant between-group difference: grade I in 52%, grade II in 36%, and grade III in 12% of patients in the HT group versus grade I in 85.7%, grade II in 9.5%, and grade III in 4.8% of those in the QTB group (P = .03). CONCLUSIONS: In patients who underwent ACL reconstruction for hyperextension of the knee, QTB yielded better clinical outcomes than HT with respect to anterior stability, rotational stability, and graft signal intensity on median 2-year follow-up magnetic resonance imaging. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

Male elite soccer players have a higher incidence of accessory ossicles in the foot and ankle.

PURPOSE: Accessory ossicles are caused by the failure of the fusion of secondary ossification centres and are more likely to occur due to heavy loading during the growth period or improper treatment after injury. This study aimed to investigate the incidence of foot and ankle accessory ossicles in male professional soccer players. METHODS: This study included male professional soccer players who underwent medical checkups at our hospital between 2017 and 2023 as the soccer group. Medical checkups included radiographs of bilateral anteroposterior and oblique foot, as well as bilateral anteroposterior and lateral ankle. Male patients age-matched with the soccer group who visited our hospital undergoing anteroposterior and oblique foot or anteroposterior and lateral ankle radiography were included in the control group. The incidence of accessory ossicles was investigated and compared between the soccer and control groups. RESULTS: In this study, 276 ankles and 276 feet, as well as 121 ankles and 79 feet, were included in the soccer and control groups, respectively. The incidence of accessory ossicles in the soccer and control groups was as follows: accessory navicular 35.9%, 24% (P = .049), os peroneum 8.0%, 2.5% (P = .09); os supranaviculare 7.6%, 1.3% (P = .039); os infranaviculare 1.4%, 1.3% (P = .090); os calcaneus secundarius 4.3%, 0% (P = .059); os vesalianum 0%, 0%; os subfiblare 12.7%, 2.5% (P < .001); os subtibiale 18.1%, 2.5% (P = .001); and os trigonum 89%, 24% (P < .001). CONCLUSIONS: Male professional soccer players had a higher incidence of accessory navicular, os supranaviculare, os subfiblare, os subtibiale, and os trigonum.

Comparative analysis of discoid lateral meniscus size: a distinction between symptomatic and asymptomatic cases.

PURPOSE: This study evaluated the differences in meniscal sizes and occupancy between symptomatic and asymptomatic patients diagnosed with discoid lateral meniscus (DLM) using magnetic resonance imaging (MRI) to understand how these variations relate to the presence of symptoms and the patients' age. METHODS: A retrospective review of 98 patients with DLM was conducted, excluding those with meniscal displacement. Both the width and extrusion of DLM and the percentage of the meniscus to the tibia were measured using mid-coronal and mid-sagittal MRI and compared between symptomatic and asymptomatic DLM groups. The relationships among each parameter, meniscal size, and patient age were evaluated. Symptomatic cases were divided into those with and without horizontal tears on MRI to compare the differences in meniscal morphology. RESULTS: A total of 92 knees from 74 patients were included. Sixty-one knees required surgical intervention for symptomatic DLM, while 31 were asymptomatic and included the contralateral side of symptomatic knees. The symptomatic group exhibited larger morphological variations than the asymptomatic group. Moreover, the sagittal meniscal ratio reduced with age in the asymptomatic group (r = - 0.54, p = 0.002) but remained constant in the symptomatic group. The symptomatic cases with horizontal tears demonstrated larger meniscal dimensions and smaller posterior capsule distances than those without tears. CONCLUSION: Symptomatic patients with DLM had larger knee morphological changes than asymptomatic ones. Age affected the meniscal occupancy in the sagittal plane only in asymptomatic patients. LEVEL OF EVIDENCE: III.

Molecular epidemiological analyses of Clostridioides difficile isolates in a university hospital in Japan.

Background: We performed molecular epidemiological analyses of Clostridioides difficile isolates in a university hospital in Japan to reveal the risk of C. difficile infection. Methods: Cultured isolates from 919 stool samples from 869 patients obtained from July 2015 to August 2016 were subjected to toxin gene detection, ribotyping, multilocus sequence typing, antimicrobial susceptibility testing, and quantitative real-time polymerase chain reaction testing for C. difficile toxin gene expression. Results: Of the 919 stool samples from 869 patients, C. difficile was isolated from 153 samples (16.6%), of which 49 (32%) and 104 (68%) were from patients with and without C. difficile infection, respectively. Analyses showed genetic diversity, with ST8 and ST17 strains of healthcare-associated infections, some of which caused C. difficile infections. There was no significant difference in the transcription levels of C. difficile toxin genes between isolates from patients with and without C. difficile infection. Conclusions: Major Japanese clonal strains, ST8 and ST17, have been in the hospital environment for a long time and cause healthcare-associated C. difficile infections. The C. difficile toxin genes were transcribed in the isolates from both patients with and without C. difficile infection but were no significant relationship with the development of C. difficile infection.

Needle-knife incision and drainage of duodenal intramural hematoma relieving duodenal and biliary obstruction.

Video 1Case presentation.

Saucerization of complete discoid lateral meniscus is associated with change of morphology of the lateral femoral condyle and tibial plateau.

PURPOSE: To determine the effect of saucerization surgery on knee joint morphology associated with a complete discoid lateral meniscus (DLM) using magnetic resonance (MR) imaging. METHODS: This retrospective study included cases had undergone saucerization surgery for symptomatic DLM between 2007 and 2022. All cases were divided into two by age group: < 12 (U13) and > 13 (O13). The cases in the match group were randomly selected from preoperative cases in the O13 group matched with the age at the final follow-up (F/U) of cases in the U13 group. The following morphological parameters were evaluated using MR images preoperatively and at the final postoperative F/U in each group: anterior obliquity of the lateral tibial plateau (AOLTP), posterior obliquity of the lateral tibial plateau (POLTP), and the lowest point of the lateral femoral condyle (LPLFC). Each parameter was compared between the U13 preoperative (pre-OP) group and the O13 pre-OP group, the preoperative and final follow-up in the U13, and the U13 group at the final F/U and the match group preoperatively. RESULTS: A total of 77 cases were evaluated. 31 cases were in the U13 pre-OP group and 46 were in the O13 pre-OP group. With a minimal F/U of 2 years, 27 cases in the U13 group and 36 in the O13 group were included. The mean F/U period was 4.6 years in the U13 group and 3.2 years in the O13 group. 32 cases were included in the match group. In the match group, the inclination of the POLTP was significantly larger (P = 0.042) and the LPLFC was more lateral (P = 0.0034) than at the final F/U in the U13 group. CONCLUSIONS: Saucerization surgery for DLM in juvenile patients can prevent progression to the characteristic bone morphology DLM. These results could help the surgeon making the decision when the surgery would be performed for symptomatic DLM patients. LEVEL OF EVIDENCE: Retrospective comparative study; level of evidence, 3.

Lateral meniscus autograft transplantation using hamstring tendon with a sandwiched bone marrow - derived fibrin clot: A case report.

INTRODUCTION AND IMPORTANCE: Tendon autograft is a durable solution for the sub/total meniscus; however it is still considered a temporary solution. CASE PRESENTATION: We report the case of a 17-year-old woman with history of subtotal lateral meniscectomy performed 6 years ago. We treated her with lateral meniscus autograft transplantation using a hamstring tendon with a sandwiched bone marrow aspirate (BMA)-derived fibrin clot. T2 relaxation times of the anterior and posterior horns of both menisci and of the cartilage were assessed. CLINICAL DISCUSSION: Lateral meniscus autograft transplantation using a hamstring tendon with a sandwiched BMA clot improved clinical and radiographic outcomes at the 24-month follow-up. These findings suggest that the lateral meniscus autograft transplantation using a hamstring tendon with a sandwiched BMA clot transformed into a meniscus-like tissue and resulted in preservation of the articular cartilage. CONCLUSION: Lateral meniscus autograft transplantation using a hamstring tendon with a sandwiched BMA clot can function as a meniscal transplant after total or subtotal meniscectomy in young patients.

Origin of Unexpected Ir3+ in a Superconducting Candidate Sr2IrO4 System Analyzed by Photoelectron Holography.

The reason for the absence of superconductivity in Sr2IrO4 was estimated by photoelectron spectra and photoelectron holograms. The analysis of the La photoelectron hologram concluded that La atoms are substituted to Sr sites. Two O 1s peaks were observed and were identified as the oxygens in the IrO2 and SrO planes by photoelectron holography and density functional theory (DFT) calculations. In the Ir 4f spectrum of Sr2IrO4, an unexpected Ir3+ peak was observed as much as 50% of all of the Ir. The photoelectron hologram of Ir3+ showed a displacement of about 0.15 Å. This displacement is thought to be due to the oxygen vacancies in the IrO2 plane. These oxygen vacancies and the associated local displacement of the atoms might inhibit superconductivity in spite of sufficient electron doping.

Inactivation of ackA and pta Genes Reduces GlpT Expression and Susceptibility to Fosfomycin in Escherichia coli.

Fosfomycin is used to treat a variety of bacterial infections, including urinary tract infections caused by Escherichia coli. In recent years, quinolone-resistant and extended-spectrum ß-lactamase (ESBL)-producing bacteria have been increasing. Because fosfomycin is effective against many of these drug-resistant bacteria, the clinical importance of fosfomycin is increasing. Against this background, information on the mechanisms of resistance and the antimicrobial activity of this drug is desired to enhance the usefulness of fosfomycin therapy. In this study, we aimed to explore novel factors affecting the antimicrobial activity of fosfomycin. Here, we found that ackA and pta contribute to fosfomycin activity against E. coli. ackA and pta mutant E. coli had reduced fosfomycin uptake capacity and became less sensitive to this drug. In addition, ackA and pta mutants had decreased expression of glpT that encodes one of the fosfomycin transporters. Expression of glpT is enhanced by a nucleoid-associated protein, Fis. We found that mutations in ackA and pta also caused a decrease in fis expression. Thus, we interpret the decrease in glpT expression in ackA and pta defective strains to be due to a decrease in Fis levels in these mutants. Furthermore, ackA and pta are conserved in multidrug-resistant E. coli isolated from patients with pyelonephritis and enterohemorrhagic E. coli, and deletion of ackA and pta from these strains resulted in decreased susceptibility to fosfomycin. These results suggest that ackA and pta in E. coli contribute to fosfomycin activity and that mutation of these genes may pose a risk of reducing the effect of fosfomycin. IMPORTANCE The spread of drug-resistant bacteria is a major threat in the field of medicine. Although fosfomycin is an old type of antimicrobial agent, it has recently come back into the limelight because of its effectiveness against many drug-resistant bacteria, including quinolone-resistant and ESBL-producing bacteria. Since fosfomycin is taken up into the bacteria by GlpT and UhpT transporters, its antimicrobial activity fluctuates with changes in GlpT and UhpT function and expression. In this study, we found that inactivation of the ackA and pta genes responsible for the acetic acid metabolism system reduced GlpT expression and fosfomycin activity. In other words, this study shows a new genetic mutation that leads to fosfomycin resistance in bacteria. The results of this study will lead to further understanding of the mechanism of fosfomycin resistance and the creation of new ideas to enhance fosfomycin therapy.

Analyses of associated factors with concomitant meniscal injury and irreparable meniscal tear at primary anterior cruciate ligament reconstruction in young patients.

Purpose: Although several factors related to the concomitant meniscal injury at anterior cruciate ligament reconstruction (ACL-R) have been investigated in a general population, few studies have identified the risk factors of meniscal tear severity in young patients in which the majority of ACL tears occur. The purpose of this study was to analyze the associated factors with meniscal injury and irreparable meniscal tear and the timeline for medial meniscal injury at ACL-R in young patients. Methods: A retrospective analysis of young patients (13 to 29 years of age) who underwent ACL-R by a single surgeon from 2005 to 2017 was conducted. Predictor variables (age, sex,body mass index [BMI], time from injury to surgery [TS], and pre-injury Tegner activity level) for meniscal injury and irreparable meniscal tear were analyzed with multivariate logistic. Results: Four hundred and seventy-three consecutive patients with an average of 31.2 months post-operative follow-up were enrolled in this study. The risk factors for medial meniscus injury were TS (<= 3 months) (odds ratio [OR], 3.915; 95% CI, 2.630-5.827; P < .0001) and higher BMI (OR, 1.062; 95% CI, 1.002-1.125; P = 0.0439). The presence of irreparable medial meniscal tears correlated with higher BMI (OR, 1.104; 95% CI, 1.011-1.205; P = 0.0281). Conclusion: An increased time from ACL tear to surgery of 3 months was strongly associated with an increased risk of medial meniscus injury, but not related to irreparable medial meniscal tear at primary ACL reconstruction in young patients. Level of Evidence: Level IV.

Effects of Oxygen on Lattice Defects in Single-Crystalline Mg2Si Thermoelectrics.

Lattice defect engineering has attracted attention due to its ability to develop thermoelectric materials with low thermal conductivity. For Mg2Si single crystals (SCs), Si vacancy (VSi) defects can be introduced and consequently result in the formation of dislocation cores. These lattice defects confer Mg2Si SCs with a lower thermal conductivity compared to Mg2Si polycrystals. To reveal a mechanism for the stabilisation of VSi in the Mg2Si SCs, we investigated the effects of oxygen (O) on lattice defects by performing electronic structure calculations, secondary ion mass spectrometry, X-ray photoelectron spectroscopy, and photoelectron holography. On the basis of these calculations, we predicted that O stabilised the formation of VSi when it was located at the Si site or at an interstitial site. All experiments confirmed the presence of O inside the Mg2Si SCs. However, O was suggested to be located not at the specific site in the crystal lattice of Mg2Si but at dislocation cores. The interaction between O and the dislocation cores in the Mg2Si SC is expected to immobilise dislocation cores, leading to the stabilisation of VSi formation.