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Background Neurologic problems after reverse total shoulder arthroplasty (RTSA) have been reported, but there are a lack of studies regarding which nerve(s) are damaged and the outcomes for the patients who had neurologic complications after RTSA. The purpose of this study was to assess the prevalence and outcomes of neurologic deficit after RTSA and to evaluate the correlation between nonanatomic rearrangement of the shoulder joint and neurologic complications after RTSA. We hypothesized that the neurologic deficit was associated with excessive distalization or lateralization of the humerus after RTSA. Methods RTSA was performed on 182 consecutive shoulders with cuff tear arthropathy. Comparative analysis was performed on 34 shoulders with (group 1) and 148 shoulders without (group 2) neurologic deficit. Results The mean follow-up period in the study was 58.5 months (range: 24-124). The mean age was 71.5 ± 7.7 years in group 1 and 73.1 ± 7.2 years in group 2. Neurologic deficit after RTSA was found in 34 shoulders (19%). The mean postoperative acromiohumeral distance was 34.1 ± 11.0 mm in group 1 and 29.4 ± 7.6 mm in group 2 (P = .015). Significant differences in terms of postoperative distalization of the humerus were seen between group 1 (24.5 ± 9.4 mm) and group 2 (20.5 ± 8.3 mm) (P = .009). The most common forms of neurologic deficit after RTSA were axillary nerve (41.2%) and radial nerve (15%) injuries. Thirty shoulders (88%) had neuropraxia, and 4 shoulders (12%) had axonotmesis. By conservative treatment, all patients with neurologic complications achieved complete recovery without any additional surgery; the mean recovery period was 7.4 months (range: 2-38 months). Conclusion Neurologic deficit occurred in 19% of patients who underwent RTSA, and it was significantly correlated with humeral distalization after surgery. Axillary nerve was mostly involved, and all patients with neurologic deficit achieved complete recovery without any additional surgery.

Few studies have assessed the outcomes of staged bilateral arthroscopic rotator cuff repair (ARCR). This study aimed to determine the influencing factors related to the outcomes of patients who underwent staged bilateral ARCR and to verify an optimal interval for performing the second rotator cuff repair in staged bilateral ARCR.We analyzed 166 shoulders that underwent staged bilateral ARCR. The average interval between the first- and second-side surgical procedures was 21.9 ± 19.7 months. The minimum follow-up period was 2 years.Clinical outcomes and retear rates were not significantly different according to the order of surgical procedures, sex, arm dominance, age, and tear size (P.05 for all). The cutoff value for the optimal interval between the first and second surgical procedures for the University of California, Los Angeles score and American Shoulder and Elbow Surgeons score was 9 months, with the area under the curve equal to 0.815 (P.001) for the University of California, Los Angeles score and 0.806 (P.001) for the American Shoulder and Elbow Surgeons score. The group with an interval of 9 months or less between the first- and second-side surgical procedures showed significantly inferior clinical outcomes and a higher retear rate (35%) compared with the group with an interval greater than 9 months (retear rate, 10%) (P.05).Staged bilateral ARCR resulted in significant improvements in clinical outcomes regardless of the order of surgical procedures, sex, arm dominance, age, and tear size. To optimize clinical outcomes of staged bilateral ARCR, second-side surgery should be delayed until 9 months after the first-side surgical procedure.

Background Isolated vocal cord palsy resulting hoarseness after shoulder surgery in beach-chair position had not been reported in literature to date. The purpose of this study was to review its incidence in our patient cohort, and identify any risk factors that may predispose the patient to the injury.Methods There were 10215 operative shoulder cases from January 2010 to December 2017. Inclusion criteria was any post-operative patients, whose operation was performed under general anesthesia in beach-chair position, who had the related symptoms, but the diagnoses had to be confirmed by otorhinolaryngologists with laryngoscopy studies. The affected patients’ clinical notes were retrospectively reviewed with the particular interest in the operative times, and the peri-operative cervical spine radiographs. The degree of cervical spine lordosis was assessed using a method described in literature, in which ‘absolute rotation angle’ (ARA) was measured. Results There were 8 reported cases of vocal cord injury in total (0.08%). Four were male patients and four were arthroscopic cases. The mean age was 59.4 ± 11.9 years old. No particular difficulties with positioning or intubation were documented. The average duration of anesthetic times was 141 minutes. On peri-operative cervical spine radiographs, the average lordosis was 8.2° (1.5° kyphosis - 21° lordosis), and except for one patient, all had ‘non-lordotic’ type curvatures. All but one patient had recovered fully with observation and expectant management, with the average recovery time being 19 weeks (range: 2 weeks to 1 year). Only patient who had not recovered during our 2-year follow-up period, had a ‘sigmoidal’ type cervical spine and was also managed with observation only.Conclusions The incidence of vocal cord injury with beach-chair positioning at our institution was low at 0.08%. The possible risk factors include long duration of the procedure and ‘non-lordotic’ cervical spine, as demonstrated by the trend in our study. Although rare, vocal cord injury has varying duration of recovery time, in the worst-case scenario being permanent, therefore it needs to be avoided by taking utmost care during positioning of the patient in beach-chair. Level of Evidence Level IV, case series

One potential advantage of arthroscopic shoulder surgery over open approaches is accelerated recovery; however, the functional recovery period of daily activities for specific movements after arthroscopic rotator cuff repair has not yet been reported, to our knowledge.(1) After arthroscopic rotator cuff repair, when are patients able to perform low-level and high-level front-of-body motion, low-level and high-level behind-the-back motion, strength-related activities, and sports/leisure activities? (2) How do tear size, arm dominance, and retear affect performance of these activities? (3) When does the UCLA score cross above 80% in each UCLA score component (28 points)?A 2-year prospective study of 135 patients who underwent arthroscopic rotator cuff repair was performed (45 in small-sized, 45 in medium-sized, and 45 in large-to-massive-sized groups). The mean age was 60 years. Thirty-one and 104 shoulders were nondominant and dominant shoulders, respectively. Twenty-seven shoulders showed retear on MRI taken 9 months after surgery. We evaluated the functional recovery periods using the questionnaire and the UCLA scores and assessed influencing factors such as tear size, arm dominance, and retear. The patients were asked to fill out a questionnaire at 1, 2, 3, 6, 9, 12, 15, 18, and 24 months after surgery. The questionnaire evaluated front-of-the-body, behind-the-back, general, simple strength-related, and sports/leisure activities. Based on the UCLA evaluation, the functional recovery period was defined as the time required to achieve a score80% in each UCLA score component.Patients experienced recovery of low-level and high-level ROM front-of-the-body, high-level ROM behind-the-back, simple strength-related, and sports/leisure activities within 2 ± 1, 3 ± 2, 9 ± 0, 10 ± 2, and 14 ± 3 months, respectively, after surgery. Two patients with large-to-massive tears did not gain the recovery of high-level ROM behind-the-back, simple strength-related, and sports/leisure activities. Patients with large-to-massive tears were delayed from some activities compared with patients with small tears (10 ± 0 versus 7 ± 1 for washing back, p = 0.010; 11 ± 0 versus 10 ± 0 for lifting 5 kg, p = 0.020; 15 ± 0 versus 13 ± 0 for sports/leisure). Arm dominance was not associated with functional recovery. Patients with retears, compared with intact healing, had a longer time to return to washing hair (3 ± 2 versus 3 ± 1, p = 0.007), combing (4 ± 3 versus 2 ± 1, p = 0.002), washing the back (10 ± 3 versus 8 ± 3, p = 0.034), and sports/leisure (15 ± 3 versus 14 ± 3, p = 0.010). UCLA score in 134 patients reached 28 points, corresponding to the functional recovery period at 6 ± 3 months. One patient did not reach28 points on the UCLA score.It took patients an average of 14 months to recover their daily motion after surgery. Tear size and retear affected only the recovery period of high-level motion activities and sports/leisure. This study was believed to serve as a guideline to inform patients about functional recovery after arthroscopic rotator cuff repair.Level III, therapeutic study.

Background This study aimed to assess the morphological degeneration of the anterior cruciate ligament (ACL) through magnetic resonance imaging (MRI) and arthroscopy. It analyzed whether the pre-operative ACL status would affect the radiologic and clinical outcomes following medial open-wedge high tibial osteotomy (MOWHTO). Methods A total of 150 knees were enrolled that underwent MOWHTO concomitant arthroscopic debridement for the treatment of varus osteoarthritis. Mean age was 56.1 ± 5.0 years and mean follow-up was 61.2 ± 21.4 months. The ACLs were staged based on MRI and arthroscopy. To exclude the influence of demographic factors on outcomes, the between-group differences were assessed. Radiologic evaluation included hip–knee–ankle angle, femorotibial angle, medial proximal tibial angle, posterior tibial slope angle, and Kellgren–Lawrence grade. Clinical evaluation included American Knee Society Score (AKSS) and knee joint range of motion (ROM). Results The ACLs were classified into intact (75 knees, 50.0%), mucoid degeneration (59, 39.3%), chronic partial tear (10, 6.7%), and complete tear (six, 4.0%) according to MRI. They were also classified into four stages: normal (95 knees, 63.3%), abnormal (36, 24.0%), partial tear (13, 8.7%), and complete tear (six, 4.0%) according to arthroscopic appearance. There were no significant between-group differences in each variable. Changes in Kellgren–Lawrence grade did not show significant between-group differences. No significant between-group differences were observed in AKSS and ROM. Conclusions The pre-operative status of ACL did not influence the outcomes following MOWHTO at midterm follow-up. Level of evidence Level IV, case series.

Strategic entrepreneurship (SE) emphasises the complementary roles played by entrepreneurship and strategic management in promoting firm growth. This article adopts two dominant concepts from each field—entrepreneurial orientation (EO) and dynamic capabilities (DCs)—to investigate their interaction effects on firm performance (FP). It further examines three contingencies—firm, market and product innovation—that significantly affect the levels of EO and DCs that firms pursue. This study analyses the influence of EO and DCs on performance using hierarchical regression models. Interaction effects of EO and DCs on FP demonstrate a positive relationship. This study found that DCs are more critical for incumbent firms than for small firms. Both EO and DCs enhance performance in dynamic markets. The EO increases performance under radical product innovation, while DCs show no effects. This study provides important and unique implications for the complementary roles of entrepreneurship and strategic management.

Background: Many studies have identified risk factors that cause retear after rotator cuff repair. However, it is still questionable whether retears can be predicted preoperatively. Purpose: To determine the risk factors related to retear after arthroscopic rotator cuff repair and to evaluate whether it is possible to predict the occurrence of retear preoperatively. Study Design: Case-control study; Level of evidence, 3. Methods: This study enrolled 112 patients who underwent arthroscopic rotator cuff repair with single-row technique for a large-sized tear, defined as a tear with a mediolateral length of 3 to 5 cm. All patients underwent routine magnetic resonance imaging (MRI) at 9 months postoperatively to assess tendon integrity. The sample included 61 patients (54.5%) in the healed group and 51 (45.5%) in the retear group. Results: In multivariate analysis, the independent predictors of retears were supraspinatus muscle atrophy ( P < .001) and fatty infiltration of the infraspinatus ( P = .027), which could be preoperatively measured by MRI. A significant difference was found between the two groups in sex, the acromiohumeral interval, tendon tension, and preoperative or intraoperative mediolateral tear length and musculotendinous junction position in univariate analysis. However, these variables were not independent predictors in multivariate analysis. The cutoff values of occupation ratio of supraspinatus and fatty infiltration of the infraspinatus were 43% and grade 2, respectively. The occupation ratio of supraspinatus Conclusion: In patients with large rotator cuff tears, it was possible to predict the retear before rotator cuff repair regardless of intraoperative factors. The retear could be predicted most effectively when the occupation ratio of supraspinatus was

Background Few studies have investigated the characteristic findings of preoperative magnetic resonance imaging (MRI) and the clinical and radiologic outcomes of interstitial tear of the rotator cuff treated with arthroscopic repair after tear completion. Methods Forty-one patients (14 men and 27 women; mean age, 56.5 years) with arthroscopically confirmed interstitial tears underwent single-row repair after tear completion. The minimum follow-up period was 2 years. Results Twenty-eight patients (68.3%) were properly evaluated with MRI before surgery. Seven cases (17.1%) were misdiagnosed as bursal-sided tears and 5 cases (12.2%) were misdiagnosed as articular-sided tears on the basis of presurgical MRI findings. Arthroscopy revealed fibrillation and dimpling of the tendon surface in all cases and congestion within the defect in 36 cases (87.8%). At the final follow-up, the visual analog scale score for pain during motion decreased to 0.8 from a preoperative mean of 6.1 ( P .001). Moreover, at the final follow-up, the mean University of California–Los Angeles score and Constant score improved from 15.7 and 51.8 to 32.1 and 83.8, respectively ( P .001 for all). At 9 months after surgery, MRI revealed no cases of retear. Conclusion Interstitial tears are difficult to diagnose before surgery because MRI findings may lead to the misdiagnosis of interstitial tears as articular- or bursal-sided tears. If MRI-based diagnosis is indicative of articular- or bursal-sided tears but arthroscopy reveals fibrillation and dimpling of the tendon surface, interstitial tears should be suspected. The defective sites in interstitial tears are usually accompanied by congestion.

Background:No studies have focused on the everted type of bursal-sided partial-thickness rotator cuff tears (PTRCTs).Purpose:To evaluate the radiological characteristics, arthroscopic findings, and clinical and structural outcomes after arthroscopic repair of the everted type of bursal-sided PTRCTs.Study Design:Cohort study; Level of evidence, 3.Methods:Two groups of patients with bursal-sided PTRCTs (simple type, 25 shoulders; everted type, 25 shoulders) were enrolled. The mean age was 59.6 years (range, 47-73 years) and 60.8 years (range, 48-72 years) among patients with the simple and everted type, respectively. The mean follow-up period was 2.7 years (range, 2.0-5.1 years).Results:The everted type always exhibited an acromial spur (hat-shaped, 52%; heel-shaped, 48%) and bony changes in the greater tuberosity (bony spur, 52%; sclerotic changes, 48%). Hat-shaped spurs of the acromion were not observed in the simple type. The everted type showed significantly thicker tendon on magnetic resonance imaging (MRI), as the stump was retracted superomedially (mean thickness: 8.1 ± 1.2 mm vs 5.5 ± 1.1 mm for the everted and simple type, respectively). During arthroscopic repair, additional sutures were needed more often for the everted type than for the simple type (64% vs 16%, respectively). After repair, the tendon margin was uneven and ragged in 16% of shoulders with the everted type. Preoperatively, the visual analog scale (VAS) score for pain during motion and range of motion (ROM) were significantly worse in patients with the everted type than in those with the simple type (VAS score, 7.2 vs 5.6, respectively; ROM for forward flexion, 146.8° vs 156.4°, respectively). Postoperatively, no significant differences in the VAS score, ROM, or clinical outcomes were observed between the 2 groups, with no retears on follow-up MRI in either group.Conclusion:The everted type of bursal-sided PTRCTs showed a characteristic hat-shaped acromion, often with bony spurs of the greater tuberosity. On MRI, the tendon stump appeared thickened because of the everted flap. The everted type was more likely to require additional sutures because of an uneven or ragged tendon margin. However, satisfactory clinical and structural outcomes were observed for both the simple and everted types.

The purpose of this study was to compare the clinical outcomes, including the level of return to sport, of collision and non-collision athletes who had the Latarjet procedure. A total of 56 shoulders of 29 collision and 27 non-collision athletes were retrospectively analyzed. All study participants underwent the Latarjet procedure between 2007 and 2014. Median age at the time of surgery was 26.5 years(18–43) and follow-up duration was 67.0 months(24–113). At the final follow-up, 54 (96.4%) patients returned to sports. Nine patients (16.1%) returned to the same level of sports. In a group of collision athletes, 1 patient (3.4%) returned to the same level, 16 (55.2%) returned to lower level, 10 (34.5%) changed sports, and 2 (6.9%) quit sports. In a group of noncollision athletes, 8 (29.6%) returned to same level, 11 (40.7%) returned at a lower level and 8 (29.6%) changed sports. The level of return to sports in collision group was statistically different from that in noncollision group (p = 0.046). The mean VAS, Rowe and UCLA scores improved significantly in both groups (p

Various techniques to release the superficial MCL (sMCL) during medial open-wedge high tibial osteotomy (MOWHTO) has been introduced. However, there have been debates regarding the extent of sMCL release in MOWHTO. The authors present a pie-crust technique that involves selective and gradual release of sMCL from inside using a small, round-tip blade after opening the gap. The aims were to introduce our novel technique regarding sMCL release and evaluate the clinical and radiologic outcomes. One-hundred sixty-six knees underwent this procedure. With a mean 60.3 months' follow-up, clinical scores were significantly improved after index operation (p

This paper examines the influence of risks on alliance governance modes in high-tech industries. The extant literature has devoted little attention to the preferred governance mode based on the risks surrounding alliances. In this paper, we examine why risks are key factors in the alliance governance decision and investigate the choice of alliance governance mode in high-tech industries. Hypotheses are formulated based on risk perspectives; these hypotheses are empirically tested using data on 3,228 alliance records generated over the past 5 years in high-tech industries. The results suggest that risk perspectives provide an effective rationale for choosing an alliance governance mode in a high-tech industry. In the conclusion, we discuss critical issues in the current debates on predicting alliance governance modes.

Although entrepreneurial orientation (EO) has been shown to play a key role in increasing firm performance (FP), the effects of EO have been extremely oversimplified. The plethora of empirical studies on EO and FP suggest that the EO–FP relationship is linearly positive regardless of the amount of EO investment. The results show that EO increases FP at the bounded level (i.e. an inverted U-shape). We argue that the excessive use of EO, organisational incapability and institutional constraints may contribute to the non-linearity of such effects. We also find that environmental dynamism has no significant effect. Further, contrary to the normative contention, we find that environmental hostility has a negative effect on the EO–FP relationship. The effect of environmental hostility on EO may vary depending on various factors such as firm size, resources, and institutional settings. We present prescriptive implications to practitioners on the antecedent conditions for EO practices.

There has been paucity in literature regarding the blood-sparing effect of TXA after high tibial osteotomy (HTO). The purpose of this study is to determine the efficacy of tranexamic acid (TXA) with regard to its blood-sparing effects in open-wedge HTO, and to assess thromboembolic complications in patients undergoing open-wedge HTO with or without the use of TXA.The intravenous TXA would reduce postoperative blood loss and transfusion requirements without increasing thromboembolic complications in open-wedge HTO.From March 2011 to December 2016, medial open-wedge HTO was performed in 150 consecutive knees with varus gonarthrosis. The mean age at the time of surgery was 55.3±5.0 years. TXA was intravenously used in the latter 75 knees (TXA group), and the group was retrospectively compared with the former 75 knees without use of TXA (control group). Outcome measures were postoperative hemoglobin drop, drain amount, total estimated blood loss, transfusion requirements, and incidence of thromboembolic complications.The use of TXA led to a significant decrease in hemoglobin drop (p0.001) and drain amount (p=0.025). Total estimated blood loss was lower in the TXA group than in the control group (p0.001). Two knees in the control group had postoperative blood transfusion, compared to none in the TXA group (p0.05). There were no thromboembolic complications such as symptomatic deep vein thrombosis and pulmonary embolism in both groups.The use of TXA reduced perioperative hemoglobin drop, drain amount, and total estimated blood loss without thromboembolic complications in patients undergoing open-wedge HTO. Therefore, the use of TXA is a safe and viable option for perioperative blood management in open-wedge HTO.III, Case control study.

Purpose To compare the radiologic and clinical outcomes in patients with and without lateral hinge fractures (LHFs) during medial open-wedge high tibial osteotomy (MOWHTO) using a locked plate system, as well as to assess whether LHFs could affect the midterm outcomes. Methods From May 2008 to November 2015, 164 knees underwent MOWHTO using a locked plate system for the treatment of knee osteoarthritis. LHFs were recognized by radiographs during or after the high tibial osteotomy and were not additionally treated. In all patients, we applied the same rehabilitation protocol that allowed full weight bearing at 6 weeks. Patients were divided into LHF (types I and II) and nonfracture groups. Radiologically, we compared any serial changes in the hip-knee-ankle angle, femorotibial angle, medial proximal tibial angle, and posterior tibial slope angle from the immediate postoperative radiographs to the final radiographs. The union process of the osteotomy site among the groups was also evaluated. Clinically, the postoperative American Knee Society Score and knee range of motion at latest follow-up were compared. Postoperative complications were also evaluated. Results The average age at operation was 56.0 years (range, 42-67 years), and the average follow-up period was 62.2 months (range, 24-120 months). LHFs were observed in 37 knees (22.6%) and were divided into the type I (16 knees) and type II (21 knees) groups. All groups showed no significant changes in serial evaluations of the postoperative hip-knee-ankle angle, femorotibial angle, medial proximal tibial angle, and posterior tibial slope angle. The improvements in the American Knee Society Score and knee range of motion were not significantly different among the groups. No patients showed correction loss or union problems. Conclusions Type I and II LHFs in MOWHTO using a medial locked plate system and relatively conservative rehabilitation protocol with full weight-bearing walking commenced at 6 weeks postoperatively showed no radiologic changes or functional deterioration during midterm follow-up. Level of Evidence Level IV, case series.

To evaluate the clinical and radiographic outcomes of patients with total elbow arthroplasty (TEA) and soft tissue reconstruction. We investigated six patients who underwent TEA and soft tissue reconstruction (two elbows with 1-stage surgery and four elbows with 2-stage surgery). The mean patient age at the time of the surgical procedure was 43.2 years; the mean follow-up duration was 88.2 months. The mean pain visual analogue scale (VAS) during motion was improved from 6.3 pre-operatively to 0.7 at the last follow-up. The mean Mayo Elbow Performance Score (MEPS) improved from 26.7 pre-operatively to 81.7 at the last follow-up. The mean flexion-extension arcs of the 1- and 2-stage surgery groups increased from 12.5° and 13.8° pre-operatively to 72.5° and 100° at the last follow-up, respectively. The mean MEPS of the one and two stage surgery groups were 75 and 85, respectively, at the last follow-up. One of the six elbows had loosening on the simple radiograph at the last follow-up, and there were no cases with bushing wear. Three elbows needed additional skin debridement owing to wound complications (2/2 elbows in the 1-stage surgery group and 1/4 elbows in the 2-stage surgery group). Under unfavorable soft tissue conditions, performing soft tissue reconstruction with TEA provides satisfactory functional improvement and pain relief. The two stage surgery provided a lower rate of wound complication and better elbow function than the one stage surgery, which led to high patient satisfaction post-operatively. Therapeutic Level IV.

To evaluate the location, magnitude, and change over time of osteolysis of coracoid grafts after Latarjet procedure. This is a retrospective study of 54 patients (55 shoulders) who underwent the Latarjet procedure. Three-dimensional computed tomography (CT) scans were performed preoperatively, immediately postoperatively, and at follow-up (mean 7.7 and 31.7 months postoperative). “En face” views of the glenoid, size of glenoid defect and changes in the glenoid surface area postoperatively were measured relative to the area of an assumed outer-fitting circle. On the oblique sagittal planes, location and subsequent severity of osteolysis of the graft at follow-up were documented. The mean glenoid surface area increased significantly from 79.7 ± 4.8% of the original circle preoperatively to 111.3 ± 8.0% immediately postoperatively. At 7.7 and 31.7 months of follow-up, glenoid surface area decreased to 102.2 ± 6.0% and 100.3 ± 5.3%, respectively. Osteolysis occurred on the outer side of the graft in all cases, but did not occur on the inner side. Maximum osteolysis was observed in the superior third of the graft (78.5 ± 17.1%), followed by the middle third (15.8 ± 10.4%), and the inferior third (8.0 ± 5.1%). No significant difference in magnitude of osteolysis was observed between 7.7 and 31.7 months of follow-up. Osteolysis of the grafted coracoid mainly occurred on the outer side of the superior portion, resulting in reshaping of the rectangular shape of graft coracoids after Latarjet procedure. Coracoid graft remodelling was almost completed approximately 8 months postoperatively to reach the original glenoid dish with no further changes thereafter. These results may help surgeons to understand changes of grafts after the surgery. IV.

A 2H-MoS2 (H=hexagonal) ultrathin nanomesh with high defect generation and large porosity is demonstrated to improving electrochemical performance, including in lithium-ion batteries (LIBs) and the hydrogen evolution reaction (HER), with the aid of a 3D reduced graphene oxide (RGO) scaffold as fast electron and ion channels. The 3D defect-rich MoS2 nanomesh/RGO foam (Dr-MoS2 Nm/RGO) can be easily obtained through a one-pot cobalt acetate/graphene oxide (GO) co-assisted hydrothermal reaction, in which GO, cobalt and acetate ions are co-morphology-controlling agents and defect inducers. As an anode material for LIBs, Dr-MoS2 Nm/RGO has only a 9% capacity decay at a 10 C discharge rate versus 0.2 C with stable cyclability at the optimized composition (5 wt% RGO to MoS2 and 2 mol% Co to Mo), and significantly achieves 810 mA h g(-1) at a high current density of 9.46 A g(-1) over at least 150 cycles. Moreover, Dr-MoS2 Nm/RGO exhibits superior activity for the HER with an overpotential as low as 80 mV and a Tafel slope of about 36 mV per decade. In contrast to the MoS2 nanosheet/RGO (MoS2 Ns/RGO), which is synthesized in the absence of cobalt ions, Dr-MoS2 Nm/RGO provides high interconnectivity for efficient lithium-ion transport, and rich defects as electrochemically active sites. DFT is used to prove the existence of rich defects due to anion replacement to become a Co-Mo-S atomic structure, releasing inert basal planes to active sites.

Silicon nanowires (SiNWs) for use as lithium-ion battery (LIB) anode materials have been studied for their one-dimensional (1D) properties and ability to accommodate large volume changes and avoid rapid capacity fading during cycling. Although the vertical transfer of SiNWs from their original substrate onto a conducting electrode is very important, to date, there has been no report of a direct integration method without polymer binders. Here, we propose for the first time a vertical transfer method for SiNWs grown on a Si substrate directly to the current-collecting electrode without using a polymer adhesive for the use as a binder-free LIB anode. The vertical SiNWs produced using a low-cost wafer-scale metal-assisted chemical etching (MaCE) process have been successfully transferred directly to a copper electrode coated with a thin Ag layer by using a simple hot pressing method. When evaluated as an LIB anode without using conventional polymeric binder and a conducting additive, the transferred vertically aligned SiNWs showed a high specific capacity (≈2150 mAh g(-1) ) and excellent rate performance. It is believed that the anode-manufacturing process is simple and fast, thus enabling a large-scale production that is of low-cost, broadly applicable, and provides new avenues for the rational engineering of Si-based electrode materials with enhanced power density and conductivity.

Morphology-controlled MoS2 nanosheets were successfully synthesized with the aid of graphene/acid coexistence by a one-pot hydrothermal method. The ultrathin MoS2 nanosheets were self-assembled into a cockscomb-like structure with an exposed (100) facet on graphene sheets, which is in strong contrast to large aggregate MoS2 plates grown freely on graphene sheets without acetic acid. The ultrathin MoS2 nanosheets displayed excellent rate performance for Li storage (709 mAh·g(-1) capacity at 8320 mA·g(-1) discharging rate) and superior charge/discharge cyclability.

Carbon-coated SnO2 nano-composite was synthesized by using a hydrothermal method in a one step process with sizes of 1 to 3 microm. The carbon-coated SnO2 nano-composite was easily obtained by changing firing atmosphere from air to argon (600 degrees C for 3 hours). The carbon-coating thickness and size of the SnO2 nanoparticles in carbon-coated SnO2 nano-composite were confirmed through a high-resolution transmission electron microscopy (HRTEM) as 40 and 5 nm, respectively. Carbon-coating and particle size affect to the capacity retention property. Carbon-coated and non carbon-coated samples were investigated as anode materials. It was confirmed that the non carbon-coated SnO2 nano-composite had a 718 mA h/g initial charge capacity, 91% reached to theoretical value of SnO2 (790 mA h/g), while the carbon-coated SnO2 nano-composite had an excellent capacity retention of 89.6% after 70 cycles (10.88% for non carbon-coated SnO2 nano-composite).

E-mail: sanghan@kriss.re.krReceived September 24, 2012, Accepted October 31, 2012We report the construction of a MALDI imaging mass spectrometer equipped with a specially designed laserfocusing lens, a compact aspherical singlet lens, that obtains a high-lateral imaging resolution in the microprobemode. The lens is specially designed to focus the ionization laser ( λ = 355 nm) down to a 1 μm diameter witha long working distance of 34.5 mm. With the lens being perpendicular to the sample surface and sharing theoptical axis with the ion path, the imaging mass spectrometer achieved an imaging resolution of as good as 5μm along with a high detection sensitivity of 100 fmol for peptides. The mass resolution was about 900 (m/Δm) in the linear TOF mode. The high-resolution capability of this instrument will provide a new researchopportunity for label-free imaging studies of various samples including tissues and biochips, even for the studyat a single cell level in the future.Key Words : Imaging mass spectrometry, High-lateral resolution, MALDI IntroductionDue to its promising potential for bioclinical applications,including biomarker discovery and disease diagnosis, matrix-assisted laser desorption/ionization (MALDI) mass spectro-metric imaging has been being actively developed in recentyears.

Introduction There has been paucity in literature regarding the blood sparing effect of TXA after high tibial osteotomy (HTO). The purpose of this study is to determine the efficacy of tranexamic acid (TXA) with regard to its blood-sparing effects in open-wedge HTO, and to assess thromboembolic complications in patients undergoing open-wedge HTO with or without the use of TXA. Hypothesis The intravenous TXA would reduce postoperative blood loss and transfusion requirements without increasing thromboembolic complications in open-wedge HTO. Materials and methods From March 2011 to December 2016, medial open-wedge HTO was performed in 150 consecutive knees with varus gonarthrosis. The mean age at the time of surgery was 55.3 ± 5.0 years. TXA was intravenously used in the latter 75 knees (TXA group), and the group was retrospectively compared with the former 75 knees without use of TXA (control group). Outcome measures were postoperative hemoglobin drop, drain amount, total estimated blood loss, transfusion requirements, and incidence of thromboembolic complications. Results The use of TXA led to a significant decrease in hemoglobin drop (p 0.05). There were no thromboembolic complications such as symptomatic deep vein thrombosis and pulmonary embolism in both groups. Conclusion The use of TXA reduced perioperative hemoglobin drop, drain amount, and total estimated blood loss without thromboembolic complications in patients undergoing open-wedge HTO. Therefore, the use of TXA is a safe and viable option for perioperative blood management in open-wedge HTO. Level of evidence III, Case control study.

Ultraviolet photodepletion spectra of dibenzo-18-crown-6-ether complexes with alkali metal cations (M(+)-DB18C6, M = Cs, Rb, K, Na, and Li) were obtained in the gas phase using electrospray ionization quadrupole ion-trap reflectron time-of-flight mass spectrometry. The spectra exhibited a few distinct absorption bands in the wavenumber region of 35 450-37 800 cm(-1). The lowest-energy band was tentatively assigned to be the origin of the S(0)-S(1) transition, and the second band to a vibronic transition arising from the "benzene breathing" mode in conjunction with symmetric or asymmetric stretching vibration of the bonds between the metal cation and the oxygen atoms in DB18C6. The red shifts of the origin bands were observed in the spectra as the size of the metal cation in M(+)-DB18C6 increased from Li(+) to Cs(+). We suggested that these red shifts arose mainly from the decrease in the binding energies of larger-sized metal cations to DB18C6 at the electronic ground state. These size effects of the metal cations on the geometric and electronic structures, and the binding properties of the complexes at the S(0) and S(1) states were further elucidated by theoretical calculations using density functional and time-dependent density functional theories.

than that of the cavity in DB18C6. Key Words : Photodepletion spectrum, Electrospray ionization, Dibenzo-18-crown-6, Quadrupole ion trapIntroductionMolecular sensors have strong affinity to specific mole-cules or ions and in most cases, their physical and chemicalproperties change significantly upon binding to them.

Electronic photofragmentation spectrum of protonated tyrosine-alanine dipeptide ions(YAH+) was obtained in the wavenumber region of 34500~36700 cm-1 using a quadrupole ion trap time-of-flight mass spectrometer (QIT-TOFMS). YAH+ ions were produced by electrospray ionization, stored in the ion trap and then irradiated by ultraviolet laser pulses which induced photofragmentation of the ions. The electronic photofragmentation spectrum was obtained by monitoring the photodissociation yields of YAH+ ions as a function of the laser wavelength. The spectrum exhibited two broad peaks which were assigned as S1 and S2 by theoretical calculations using a time-dependent density functional method. The broad widths of the peaks in the spectrum were explained by the overlaps of the peaks originated from various conformers of YAH+ ions which were present in the gas phase at room temperature and also by the contributions of the hot bands.

We have constructed a quadrupole ion trap time-of-flight mass spectrometer to study photo-induced dissociation (PID) of biologically important molecules in the gas phase. The performance and capabilities of the mass spectrometer were investigated by measuring the mass spectra of protonated peptide ions produced by electrospray ionization. The typical mass resolution (m/Δm) was around 1000 and the collection efficiency measured for photo-fragment ions of protonated Tyr-Ala ions (YAH + ) was about 41%. The PID spectra of YAH + and protonated Gly-Trp ions (GWH + ) were compared to their respective spectra obtained by collisioninduced dissociation in the same instrument. The chromophore effect in photodissociation of protonated peptide ions was addressed with the PID spectrum of GWH + .

We report a synthetic scheme for preparing a SnO2–Sn–carbon triad inverse opal porous material using the controlled sintering of Sn precursor-infiltrated polystyrene (PS) nanobead films. Because the uniform PS nanobead film, which can be converted into carbon via a sintering step, uptakes the precursor solution, the carbon can be uniformly distributed throughout the Sn-based anode material. Moreover, the partial carbonization of the PS nanobeads under a controlled Ar/oxygen environment not only produces a composite material with an inverse opal-like porous nanostructure but also converts the Sn precursor/PS into a SnO2–Sn–C triad electrode.

Background: Because of the anatomic and biomechanical differences between the lateral and medial menisci, it is believed that the indications, combined injuries, techniques, and outcomes of the 2 meniscus allograft transplantation (MAT) procedures may be different. Hypothesis: Medial meniscus transplantation (medial group) usually combines concomitant surgeries, such as anterior cruciate ligament (ACL) reconstruction, so the medial group will have worse clinical results than the lateral group (lateral meniscus transplantation). Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective study was conducted on 91 patients who underwent MAT (lateral group, n = 56; medial group, n = 35). There were 33 patients with an absence of a concurrent injury (isolated group) and 58 patients with the presence of a concurrent injury (combined group). The mean follow-up was 40 months (range, 24-125 months). Clinical outcomes for range of motion (ROM), visual analog scale (VAS) for pain score, International Knee Documentation Committee (IKDC) subjective score, Lysholm score, and Tegner activity score were evaluated, and an objective evaluation was performed using magnetic resonance imaging (MRI) and second-look arthroscopic surgery. Results: At final follow-up, the mean results for ROM, VAS score, IKDC subjective score, Lysholm score, Tegner activity score, and patient subjective satisfaction were not statistically different between the lateral and medial groups ( P > .05). The VAS and Lysholm scores of the isolated group were significantly better than those of the combined group. Follow-up MRI was performed on 35 patients (24 in the lateral group and 11 in the medial group). Mean graft extrusion was 1.7 mm in the lateral group and 2.6 mm in the medial group ( P = .075). The relative percentage of extrusion was 19.4% in the lateral group and 32.0% in the medial group ( P = .011). Anterior cruciate ligament reconstruction occurred more commonly in the medial group, and cartilage procedures occurred more commonly in the lateral group. Conclusion: The clinical results of the lateral group were not different from those of the medial group. More graft extrusion was found in the medial group on MRI, and second-look arthroscopic surgery results of the lateral group were not as good as those of the medial group. The VAS and Lysholm scores of the combined group were worse than those of the isolated group. With regard to concomitant surgery, ACL reconstruction was most common in the medial group and cartilage procedures in the lateral group.

MoS2 nanosheets are prepared from a neutralized aqueous solution of graphene oxide, (NH4)6Mo7O24, and thiourea followed by hydrothermal treatment (autoclave, 240 °C, 12 h) in the presence of glacial acetic acid as suppressor for growth in c-axis direction and NaOH as reducing agent.

This paper examines the impact of two theoretical frameworks - transaction cost economics (TCE) and resource-based view (RBV) - on alliance processes among Korean high-tech manufacturing ventures. Results show that TCE and RBV can be applied complementarily to explain the formation of technological alliances. TCE variables are more related with alliance partner characteristics, while RBV is linked with partner capabilities. Both show positive effects on performance. No significant effect is found regarding alliance governance structure. While selecting appropriate technological alliance partners shows positive effects on performance, no significant effect is found between alliance governance structure and performance. Elements of both theories impacting each alliance stage and analytical explanations of such impacts are discussed.

This paper examines the impact of two main alliance motivation theories, transaction cost economics (TCE) and resource based view (RBV), on alliance processes among Korean manufacturing high-tech ventures. Results show that TCE and RBV are complimentarily explaining the formation of inter-firm alliances. TCE variables are more related with alliance partner characteristics while RBV is more linked with partner capabilities. Both show positive effects on performance. No significant effect is found on determining an alliance governance structure. While selecting appropriate technological alliance partners show positive effects on performance, no significant effect is found between alliance governance structure and performance. Factors of both theories impacting each alliance stage and analytical explanations of such impacts are discussed.

Limb length changes were evaluated after closed- and open-wedge high tibial osteotomies (HTOs) using computer-assisted surgery. A total of 78 closed- and 30 open-wedge HTOs were performed. The changes in limb length were evaluated on a navigation system and radiographs. The correction angle was defined as the difference between the pre and postoperative mechanical axis on the navigation system. The change in limb length with respect to the correction angle was analyzed. Following the closed-wedge HTOs, the mean changes in limb length based on the navigation system and radiographs were −1.3 ± 1.9 and −1.3 ± 10.7 mm, respectively, versus 6.2 ± 2.6 and 7.8 ± 2.9 mm after the open-wedge HTOs. The mean correction angle was 11.6 ± 3.2° for closed-wedge HTOs and 11.5 ± 1.9° for open-wedge HTOs. The correction angle did not affect the change in limb length after closed-wedge HTO, while the larger the correction angle required, the greater the increase in limb length after open-wedge HTO. The change in limb length was negligible after closed-wedge HTO, while the limb length was increased slightly after open-wedge HTO. The possibility of limb lengthening must be considered carefully when determining whom to perform open-wedge HTO on, especially when a large correction angle is required. III.

Ultraviolet photodepletion spectra of dibenzo-18-crown-6-ether complexes with alkaline earth metal divalent cations (A(2+)-DB18C6, A = Ba, Sr, Ca, and Mg) were obtained in the gas phase using electrospray ionization quadrupole ion-trap reflectron time-of-flight mass spectrometry. Each spectrum exhibits the lowest energy absorption band in the wavenumber region of 35 400-37 800 cm(-1), which is tentatively assigned as the origin of the S(0)-S(1) transition of A(2+)-DB18C6. This origin band shows a red shift as the size of the metal dication increases from Mg(2+) to Ba(2+). The binding energies of the metal dications to DB18C6 at the S(0) state were calculated at the lowest energy structures optimized by the density functional theory and employed with the experimental energies of the origin bands to estimate the binding energies at the S(1) state. We suggest that the red shifts of the origin bands arise from the decrease in the binding energies of the metal dications at the S(1) state by nearly constant ratios with respect to the binding energies at the S(0) state, which decrease with increasing size of the metal dication. This unique relationship of the binding energies between the S(0) and S(1) states gives rise to a linear correlation between the relative shift of the origin band of A(2+)-DB18C6 and the binding energy of the metal dication at the S(0) state. The size effects of the metal cations on the properties of metal-DB18C6 complex ions are also manifested in the linear plot of the relative shift of the origin band as a function of the size to charge ratio of the metal cations, where the shifts of the origin bands for all DB18C6 complexes with alkali and alkaline earth metal cations are fit to the same line.

A photodepletion spectrum of gaseous protonated tyrosine molecules was obtained at 150 K by a UV laser spectroscopic technique in conjunction with mass spectrometry and interpreted by theoretical methods. The spectrum exhibits three distinct bands separated each other by about 800 cm(-1). Stable conformers of the molecular ion were determined by quantum mechanical density functional theory, and their electronic transition energies were obtained by a semiempirical quantum chemistry calculation. The whole pattern of the spectrum was reasonably reproduced by a combination of theoretical methods, the second-order cumulant expansion, a semiempirical quantum chemistry method, molecular dynamics simulation, and a semiclassical time-correlation function approach. The three spectral bands turned out to arise from the vibronic transition of two vibrational modes constituted by the "benzene breathing" mode and a torsional mode of the amino acid backbone. It is suggested that the major factor in spectral broadening is not conformational disorder or lifetime broadening but thermal fluctuation of the stable conformers. The good agreement between experimental and theoretical spectra exemplifies the validity of the theoretical methods applied for the present molecular system.

This paper explores the drivers of firms to enter into technological alliances by testing the relative effects of social networks and absorptive capacity on partner selection, governance and alliance performance. The results show within the sample of Korean high-tech SMEs that absorptive capacity is the primary driver of partner selection and alliance performance than social networks. However, neither absorptive capacity nor social networks were found to significantly affect the choice of technological alliance governance mode. Based on these findings, this study posits the driver of technological alliance formation among Korean SMEs is absorptive capacity. Discussion of these conclusions and implications for academics and business practitioners are discussed in the closing section of the paper.

Herein, we first report a facile synthetic route for preparing micron-sized particles comprising TiO(2)-B nanotubes, namely, skein shaped TiO(2)-B nanotube cluster particles with an ultra high surface area of 257 m(2) g(-1). The galvanostatic charge-discharge test showed that the hierarchical micron-sized particles composed of TiO(2)-B nanotubes with approximately 10 nm in diameter exhibited outstanding rate capability as well as high specific capacity.

Hip joint preserving osteotomy surgery is the treatment of choice for young patients with early symptomatic structural abnormalities of the acetabulum and proximal femur. This is true even in the absence of severe secondary degenerative changes. These disorders can include hip instability from classic developmental dysplasia, post- traumatic acetabular dysplasia, hip impingement from retrotorsional acetabular deformities, or, rarely, post-traumatic problems. During the past 20 years, various techniques of acetabular and proximal femoral reorientation have evolved, making the procedure reliable, reproducible, and durable. In this report, the current indications and results of acetabular and proximal femoral osteotomies in patients with symptomatic acetabular structural problems will be discussed.