Regional and annual patterns in respiratory virus co-infection etiologies and antibiotic prescriptions for pediatric mycoplasma pneumoniae pneumonia.

OBJECTIVE: Mycoplasma pneumoniae (M. pneumoniae) pneumonia is the second-most common cause of community-acquired pneumonia (CAP). This study aimed at investigating into the prevalence of macrolide-resistant M. pneumoniae (MRMP) with respiratory virus co-infection and the antibiotic prescriptions in children with CAP in four provinces in Korea, and to assess the variations in the findings across regions and throughout the year. PATIENTS AND METHODS: This prospective study was conducted in 29 hospitals in Korea between July 2018 and June 2020. Among the enrolled 1,063 children with CAP, all 451 patients with M. pneumoniae underwent PCR assays of M. pneumoniae and respiratory viruses, and the presence of point mutations of residues 2063 and 2064 was evaluated. RESULTS: Gwangju-Honam (88.6%) showed the highest prevalence of MRMP pneumonia, while Daejeon-Chungcheong (71.3%) showed the lowest, although the differences in prevalence were not significant (p=0.074). Co-infection of M. pneumoniae pneumonia and respiratory virus was observed in 206 patients (45.4%), and rhinovirus co-infection (101 children; 22.2%) was the most frequent. The prevalence of MRMP pneumonia with respiratory virus co-infection and the antibiotic prescriptions differed significantly among the four provinces (p < 0.05). The monthly rate of MRMP pneumonia cases among all cases of M. pneumoniae pneumonia and tetracycline or quinolone prescriptions did not differ significantly among the four regions (trend p > 0.05) during the study period. CONCLUSIONS: The prevalence of M. pneumoniae pneumonia with virus co-infection and antibiotic prescriptions could differ according to region, although the MRMP pneumonia rate showed no difference within Korea.

Atypical periprosthetic femoral fracture with stem breakage: a case report.

Although the American Society for Bone and Mineral Research definition of atypical femoral fracture excludes periprosthetic fractures, fractures around the prosthesis with clinical features of atypical femoral fractures have been reported in the literature. All fractures reported thus far have been distal to the prosthetic segment; however, we encountered a case of a stress fracture in the middle of the femoral component segment. An 86-year-old woman with a history of bisphosphonate osteoporosis treatment and revisional total hip arthroplasty visited our outpatient clinic complaining of pain in the left thigh and groin. We diagnosed an incomplete atypical femoral fracture around the hip prosthesis; medical treatment was implemented. Two months later, the patient visited the emergency department with a complete subtrochanteric fracture with stem breakage. Without revision of the broken stem, two plates were applied after reduction. In this case, we recognized the possibility of a stress fracture but overlooked the possibility of stem breakage in an atypical femoral fracture. Even if it is not evident on the radiograph before complete fracture, clinicians should be alert to the signs of stress fracture in the middle of the femoral component segment, as they may be clues to atypical periprosthetic femoral fracture with stem failure. Isolated medical treatment plans are not recommended for incomplete subtrochanteric atypical periprosthetic femoral fracture. Instead, concomitant prophylactic plate fixation is recommended.

Colloid coload versus crystalloid coload to prevent maternal hypotension in women receiving prophylactic phenylephrine infusion during caesarean delivery: a randomised controlled trial.

BACKGROUND: The optimal fluid strategy to prevent maternal hypotension during caesarean delivery remains unclear. This study aim was to compare the incidence of post-spinal anaesthesia hypotension in women receiving either colloid or crystalloid coload in the setting of prophylactic phenylephrine infusion during caesarean delivery. METHODS: Healthy mothers undergoing elective caesarean delivery under spinal anaesthesia were randomised to receive a rapid intravenous coload with 6% hydroxyethyl starch 130/0.4 10 mL/kg (colloid group) or balanced crystalloid solution (Plasma Solution A) 10 mL/kg (crystalloid group) during spinal anaesthesia. All women had a prophylactic phenylephrine infusion initiated at 25 µg/min immediately after the subarachnoid block and titrated to systolic blood pressure using a standardised protocol. The primary outcome was the incidence of hypotension (systolic blood pressure <80% of baseline) until delivery. RESULTS: The incidence of hypotension was 50% in the colloid group and 62% in the crystalloid group (absolute difference, -12% [95% CI -33% to 9%]; relative risk, 0.8 [95% CI 0.56 to 1.14]; P=0.314). No significant difference between groups was found in the number of hypotensive episodes (median 0.5 [IQR 0 to 1] vs 1 [0 to 2], P=0.132) or phenylephrine dose (675 [IQR 425 to 975] µg vs 750 [625 to 950] µg, P=0.109). The incidence of severe hypotension, symptomatic hypotension, bradycardia, nausea, and the neonatal outcomes were not significantly different. CONCLUSIONS: This study found no benefit of colloid coload compared with crystalloid coload for preventing maternal hypotension in the presence of prophylactic phenylephrine infusion during caesarean delivery.

Subtrochanteric atypical femoral fracture induced solely by glucocorticoid without bisphosphonate treatment: a case report.

An AFF is a form of stress fracture induced by excessive physiologic repetitive stress over the bone remodeling capacity. Although glucocorticoid administration is a known risk factor for AFF, no case of AFF with glucocorticoid administration as the only risk factor has been previously reported. In this report, we aimed to highlight the risk of AFF associated with long-term administration of glucocorticoids, and the importance of surveillance and correction of risk factors in patients undergoing long-term glucocorticoid therapy. A 58-year-old male patient was diagnosed with subtrochanteric AFF. He had no medical history of any condition that might disrupt bone metabolism and no known risk factors for AFF, except for long-term administration of glucocorticoid. After fixation of the fracture, the glucocorticoid was replaced with an alternative medication. Although AFF is notorious for delayed union or nonunion, complete union of the fracture was obtained at 14 months postoperatively. This case brought to our attention the possibility that glucocorticoids alone may be responsible for inducing AFF and highlighted the importance of regular assessments in case of necessity of glucocorticoid administration. Additionally, correction of risk factors might expedite the union of AFF.

Incidence of oral anticoagulant interruption among stroke patients with atrial fibrillation and subsequent stroke.

BACKGROUND AND PURPOSE: We analyzed the incidence and causes of oral anticoagulant (OAC) cessation and subsequent stroke after OAC withdrawal in a cohort of Korean stroke patients with atrial fibrillation. METHODS: The Korean Atrial Fibrillation Evaluation Registry in Ischemic Stroke patients (K-ATTENTION) is a multicenter cohort study, merging stroke registries from 11 tertiary centers in Korea. The number of OAC interruption episodes and the reasons were reviewed from hospital records. Stroke after OAC withdrawal was defined when a patient experienced ischaemic stroke within 31 days after OAC withdrawal. Clinical variables were compared between patients who experienced stroke recurrence during OAC interruption and those who did not experience recurrence. RESULTS: Among 3213 stroke patients with atrial fibrillation, a total of 329 episodes of OAC interruption were detected in 229 patients after index stroke (mean age 72.9 ± 8.3 years, 113 female patients). The most frequent reason for OAC withdrawal was poor compliance [103 episodes (31.3%)] followed by extracranial bleeding [96 episodes (29.2%)]. Stroke after OAC withdrawal was noted in 13 patients. Mean age, vascular risk factor profile and mean CHA2 DS2 -VASc score were not significantly different between patients with and without recurrent stroke. CONCLUSIONS: A considerable number of stroke patients with atrial fibrillation experienced temporary interruption of OAC after index stroke, which was associated with stroke recurrence of 4.0 cases per 100 interruption episodes.

Association between time to treatment and functional outcomes according to the Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score in endovascular stroke therapy.

BACKGROUND AND PURPOSE: The rate at which the chance of a good outcome of endovascular stroke therapy (EVT) decays with time when eligible patients are selected by baseline diffusion-weighted magnetic resonance imaging (DWI-MRI) and whether ischaemic core size affects this rate remain to be investigated. METHODS: This study analyses a prospective multicentre registry of stroke patients treated with EVT based on pretreatment DWI-MRI that was categorized into three groups: small [Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS)] (8-10), moderate (5-7) and large (<5) cores. The main outcome was a good outcome at 90 days (modified Rankin Scale 0-2). The interaction between onset-to-groin puncture time (OTP) and DWI-ASPECTS categories regarding functional outcomes was investigated. RESULTS: Ultimately, 985 patients (age 69 ± 11 years; male 55%) were analysed. Potential interaction effects between the DWI-ASPECTS categories and OTP on a good outcome at 90 days were observed (Pinteraction  = 0.06). Every 60-min delay in OTP was associated with a 16% reduced likelihood of a good outcome at 90 days amongst patients with large cores, although no associations were observed amongst patients with small to moderate cores. Interestingly, the adjusted rates of a good outcome at 90 days steeply declined between 65 and 213 min of OTP and then remained smooth throughout 24 h of OTP (Pnonlinearity  = 0.15). CONCLUSIONS: Our study showed that the probability of a good outcome after EVT nonlinearly decreased, with a steeper decline at earlier OTP than at later OTP. Discrepant effects of OTP on functional outcomes by baseline DWI-ASPECTS categories were observed. Thus, different strategies for EVT based on time and ischaemic core size are warranted.

Associations of various blood pressure parameters with functional outcomes after endovascular thrombectomy in acute ischaemic stroke.

BACKGROUND AND PURPOSE: High blood pressure (BP) at presentation is associated with poor outcomes in acute ischaemic stroke, but serial BP measurements may better delineate the clinical implications of BP. The aim was to investigate the association between various BP parameters and functional outcomes in acute ischaemic stroke patients treated with endovascular thrombectomy (EVT). METHODS: This study reports a retrospective analysis of a prospective registry of a comprehensive stroke centre. Patients treated with EVT due to large vessel occlusion in the anterior circulation were enrolled. BP was measured hourly during the first 24 h after admission. Associations of various BP parameters, including BP variability, with functional outcomes at 3 months, including good outcomes (modified Rankin Scale score of 0-2), were analysed. RESULTS: Of the 378 enrolled patients (mean age 70 ± 11 years, male 54.2%), 313 (82.8%) achieved successful reperfusion after EVT, and 149 (39.4%) had good outcomes at 3 months. Higher mean systolic BP [each 10 mmHg increase, odds ratio 0.82 (0.69-0.97)] and higher systolic successive variation (SV) [each 10% increase, odds ratio 0.37 (0.18-0.76)] were associated with a reduced likelihood of achieving good outcomes. In addition, reperfusion status after EVT moderated the influence of higher systolic SV on good outcomes (Pint  = 0.05). CONCLUSION: The results showed that a higher mean systolic BP and systolic SV during the first 24 h of EVT reduced the likelihood of good outcomes at 3 months. The effects of these parameters on outcomes are more substantial amongst patients with successful reperfusion after EVT, suggesting that different BP control strategies should be employed according to reperfusion status.

Comparison between general, spinal, epidural, and combined spinal-epidural anesthesia for cesarean delivery: a network meta-analysis.

BACKGROUND: This study is a network meta-analysis to compare maternal and fetal outcomes associated with four different anesthetic techniques for cesarean delivery. METHODS: An arm-based, random-effects frequentist network meta-analysis was performed. A random effect model was selected considering deviance information criteria. Randomized trials reporting the following outcomes were included: Apgar score at 1- or 5-min; umbilical arterial and venous pH; umbilical arterial pH <7.2; and neonatal score at 2-4 hours. Loop-specific heterogeneity was evaluated by risk of odds ratio and τ2. Quality of evidence was assessed using the GRADE approach. RESULTS: Data from 46 randomized trials including 3689 women contributed to the study. There were significant differences in Apgar score ≤6 at 1 min between spinal versus general anesthesia (odds ratio 0.27, 95% confidence interval [CI] 0.13 to 0.55: moderate quality evidence) and Apgar scores at 1- and 5-min, favoring spinal anesthesia. Umbilical venous pH associated with epidural anesthesia was significantly higher than that with general anesthesia (mean difference 0.010, 95% CI 0.001 to 0.020: moderate quality evidence) or spinal anesthesia. Spinal anesthesia was ranked best for Apgar score ≤6 at 1-min (SUCRA=89.8), Apgar score at 1-min (SUCRA=80.4) and 5-min (SUCRA=90.5). Epidural anesthesia was ranked highest for umbilical venous pH (SUCRA=87.4) and neonatal score (SUCRA=79.3). CONCLUSIONS: Spinal and epidural anesthesia were ranked high regarding Apgar scores and epidural anesthesia was ranked high regarding umbilical venous pH, but the results were based on small heterogeneous studies with high or unclear risks of bias.

Phase-Only Rotation Invariant Correlation Using Synthesized Phase Objects.

We present a development of the method of synthesized phase objects (SPO-method) (P. V. Yezhov, et al. Opt. Exp. 20, 29854 (2012)) for the phase-only rotation invariant pattern recognition. It has been performed a comparison of correlation signals for a set of amplitude objects under their rotation by using the standard and SPO methods, by applying the Fourier-Mellin transformation. The results of both calculation and optical experiments carried out using an optical-digital correlator with SLM in the Fourier plane have been presented.

Seldinger vs modified Seldinger techniques for ultrasound-guided central venous catheterisation in neonates: a randomised controlled trial.

BACKGROUND: Central venous catheterisation in neonates is difficult. The purpose of this study was to compare the Seldinger and modified Seldinger techniques for ultrasound-guided internal jugular vein catheterisation in neonates. METHODS: In this randomised, controlled trial, 120 neonates (≤1 month old) requiring central venous catheterisation under general anaesthesia were allocated into either the Seldinger (n=60) or the modified Seldinger (n=60) group. The primary outcome was the incidence of successful catheterisation on the first attempt. We also assessed the incidences of successful puncture on the first attempt, successful guide wire insertion on the first attempt, and successful final catheterisation. RESULTS: The primary outcome, the incidence of successful catheterisation on the first attempt was higher in the modified Seldinger group than in the Seldinger group (83% vs 65%; relative risk=1.282; 95% confidence interval, 1.032-1.594; P=0.025). The incidence of successful guide wire insertion on the first attempt was also higher in the modified Seldinger group (95% vs 75%; relative risk=1.267; 95% confidence interval, 1.082-1.482; P=0.003). Other incidences did not differ significantly between the groups. CONCLUSIONS: For ultrasound-guided internal jugular vein catheterisation in neonates, the modified Seldinger technique showed superiority over the Seldinger technique in terms of successful catheterisation and guide wire insertion on the first attempt. CLINICAL TRIAL REGISTRATION: NCT02688595.

Effect of prolonged inspiratory time on gas exchange during robot-assisted laparoscopic urologic surgery.

BACKGROUND: Gas exchange disturbance may develop during urologic robotic laparoscopic surgery with the patient in a steep Trendelenburg position. This study investigated whether prolonged inspiratory time could mitigate gas exchange disturbances including hypercapnia. METHODS: In this randomized cross-over trial, 32 patients scheduled for robot-assisted urologic surgery were randomized to receive an inspiratory to expiratory time ratio (I:E) of 1:1 for the first hour of pneumoperitoneum followed by 1:2 for last period of surgery (group A, n = 17) or I:E of 1:2 followed by 1:1 (group B, n = 15). Arterial blood gas analysis, airway pressure and hemodynamic variables were assessed at four time points (T1: 10 min after induction of general anesthesia, T2: 1 h after the initiation of pneumoperitoneum, T3: 1 h after T2 and T4: at skin closure). The carry over effect of initial I:E was also evaluated over the next hour through arterial blood gas analysis. RESULTS: There was a significant decrease in partial pressure of oxygen in arterial blood (PaO2) for both groups at T2 and T3 compared to T1 but in group B the PaO2 at T4 was not decreased from the baseline. Partial pressure of carbon dioxide in arterial blood (PaCO2) increased with I:E of 1:2 but did not significantly increase with I:E of 1:1; however, there were no differences in PaO2 and PaCO2 between the groups. CONCLUSION: Decreased oxygenation by pneumoperitoneum was improved and PaCO2 did not increase after 1 h of I:E of 1:1; however, the effect of equal ratio ventilation longer than 1 h remains to be determined. There was no carryover effect of the two different I:E ratios.

Flexion decreases the ventilation quality of the Ambu® AuraGain™ laryngeal mask in paralysed children: A prospective randomised crossover study.

BACKGROUND: The influence of different head and neck positions on ventilation with the Ambu® AuraGain™ remains unevaluated in children. This study assessed the influence of different head and neck positions on ventilation with the AuraGain™ in paediatric patients. METHODS: In this prospective, randomised crossover study, children ≤7 years of age who were scheduled for elective surgery under general anaesthesia were enrolled. An AuraGain™ was placed in all patients; mechanical ventilation was performed using a volume-controlled mode with a tidal volume of 10 mL/kg. Respiratory rate was adjusted to maintain a ET CO2 of 35-40 mm Hg. The oropharyngeal leak pressure, expiratory tidal volume, peak inspiratory pressure, ventilation score and fibreoptic bronchoscopic view score were assessed for the neutral head and neck position, and then for the flexed, extended and rotated head and neck positions in a random order. RESULTS: Compared with the neutral position, the oropharyngeal leak pressure increased in the flexed position (P < .001), and decreased in the extended (P = .014) and rotated position (P = .002). The expiratory tidal volume and ventilation score were significantly reduced during flexion (all P < .005), and were comparable among the neutral, extended and rotated positions. The fibreoptic score improved in the extended and rotated position (all P < .001). Only the flexion ventilation score was lower compared with the neutral position (P = .014). CONCLUSIONS: Clinically, the flexed head and neck positions negatively affected ventilation due to obstruction of the airway. Ventilation with AuraGain™ can be effectively performed with the head and neck in the neutral, extended and rotated position in paediatric patients.

The effect of 6% hydroxyethyl starch (130/0.4) on acute kidney injury in paediatric cardiac surgery: a prospective, randomised trial.

We have evaluated the effect of a colloid solution on acute kidney injury in paediatric cardiac surgery. A total of 195 patients were ramdomly divided into an hydroxyethyl starch group and a control group. In the starch group, 6% hydroxyethyl starch 130/0.4 (Volulyte® ) was used as the primary fluid for volume resuscitation but was limited to 30 ml.kg-1 . In the control group, only crystalloid fluid was used during the peri-operative period. The incidence of acute kidney injury, peri-operative transfusion, clinical outcomes and laboratory data were compared. The incidence of acute kidney injury determined by Paediatric Risk, Injury, Failure, Loss, End-stage renal disease (pRIFLE) and Acute Kidney Injury Network (AKIN) criteria were no different between the two groups (starch group 40.8% vs. control group 30.0%; p = 0.150 using pRIFLE; 19.6% vs. 21.1% respectively, p = 0.602 using AKIN). There were no differences in clinical outcomes such as mortality, major adverse events, intensive care unit stay or duration of mechanical ventilation. Clotting time as measured using rotational thromboelastometry (ROTEM) was prolonged, and clot firmness after 10 min and maximal clot firmness were shorter in the starch group compared with the control group after sternal closure. There was no difference in transfusion between the two groups. Patients with acute kidney injury had worse clinical courses than those without acute kidney injury. We conclude that intra-operative use of 6% hydroxyethyl starch 130/0.4 up to 30 ml.kg-1 was not associated with postoperative acute kidney injury in paediatric cardiac patients.

Real-time ultrasound-guided axillary vein cannulation in children: a randomised controlled trial.

The axillary vein is a good site for ultrasound-guided central venous cannulation in terms of infection rate, patient comfort and its anatomical relationship with the clavicle and lungs. We compared real-time ultrasound-guided axillary vein cannulation with conventional infraclavicular landmark-guided subclavian vein cannulation in children. A total of 132 paediatric patients were randomly allocated to either ultrasound-guided axillary vein (axillary group) or landmark-guided subclavian vein (landmark group). The outcomes measured were success rate after two attempts, first-attempt success rate, time to cannulation and complication rate. The success rate after two attempts was 83% in the axillary group compared with 63% in the landmark group (odds ratio 2.85, 95%CI 1.25-6.48, p = 0.010). The first-attempt success rate was 46% for the axillary group and 40% for the landmark group (p = 0.274) and median time to cannulation was 156 s for the axillary group and 180 s for the landmark group (p = 0.286). There were no differences in complication rates between the two groups, although three episodes of subclavian artery puncture occurred in the landmark group (p = 0.08). We conclude that axillary vein cannulation using a real-time ultrasound-guided in-plane technique is useful and effective in paediatric patients.

Assessment of dynamic variables of fluid responsiveness to predict desufflation-induced hypotension during paediatric laparoscopic surgery.

BACKGROUND: During laparoscopic surgery in paediatric patients, sudden hypotension may occur following peritoneal desufflation due to hypovolaemia or an acute increase in gastrointestinal venous capacitance by the release of intra-abdominal pressure. This study examined whether dynamic variables of fluid responsiveness during pneumoperitoneum can predict the occurrence of hypotension following desufflation. METHODS: A total of 120 paediatric subjects were prospectively enrolled. A predictor was derived from the initial 83 subjects and validated thereafter in 37 high-risk subjects. The pleth variability index, respiratory variation in the pulse oximetry plethysmographic waveform (ΔPOP), systolic pressure variation and pulse pressure variation during pneumoperitoneum were obtained 1 min before desufflation. Predictors of desufflation-induced hypotension were investigated using the multivariable logistic regression analysis. Predictability was assessed using the area under the receiver-operating characteristic curve (AUC). RESULTS: In the derivation cohort, 27% (n=23) of subjects developed hypotension. Only ΔPOP was found to be a predictor, and showed high predictability of desufflation-induced hypotension [AUC 0.87, P<0.0001, 95% confidence interval (CI): 0.78-0.93]. A ΔPOP cut-off point of 38% predicted hypotension with a sensitivity of 83% and a specificity of 90%. In the validation cohort, 43% (n=16) of subjects developed hypotension, and ΔPOP was verified to be highly predictive of the occurrence of hypotension (AUC 0.90, P<0.0001, 95% CI: 0.76-0.98). The sensitivity and specificity of a ΔPOP cut-off point of 38% to predict hypotension was 88% and 90%, respectively. CONCLUSIONS: The ΔPOP during pneumoperitoneum is useful in predicting desufflation-induced hypotension during paediatric laparoscopic surgery. CLINICAL TRIAL REGISTRATION: NCT02536521.

The incidence and characteristics of 3-month mortality after intraoperative cardiac arrest in adults.

BACKGROUND: There is little information about clinical outcomes after intraoperative cardiac arrest (IOCA). We determined the incidence and characteristics of 3-month mortality after IOCA. METHODS: The electronic medical records of 238,648 adult surgical patients from January 2005 to December 2014 were reviewed retrospectively. Characteristics of IOCA were documented using the Utstein reporting template. RESULTS: IOCA occurred in 50 patients (21/100,000 surgeries). Nineteen patients died in the operating room, and further 12 patients died within 3 months post-arrest (total mortality: 62%). Three survivors at 3 months post-arrest had unfavourable neurological outcome. Finally, 34 patients showed unfavourable clinical outcomes at 3 months post-arrest. The incidences of non-cardiac surgery, emergency, pre-operative intubation state, non-shockable initial cardiac rhythm, hypovolaemic shock, pre-operative complications-induced cardiac arrest, non-anaesthetic cause of cardiac arrest, intra- and post-arrest transfusion, and continuous infusion of inotrope or vasopressor in intensive care unit (ICU) were significantly higher in non-survivors at 3 months post-arrest. Total epinephrine dose administrated during arrest was higher, and the duration of cardiac compressions was longer in non-survivors at 3 months post-arrest. CONCLUSIONS: In this study, the incidence of IOCA was 21/100,000 surgeries and the 3-month mortality rate after IOCA was 62%. Several factors including surgical emergency, non-shockable initial cardiac rhythm, pre-operative complications, surgical complications, long duration of cardiac compressions, high total epinephrine dose, transfusion, and continuous infusion of inotropes or vasopressors in ICU seemed to be risk factors for 3-month mortality after IOCA. These risk factors should be considered in the light of relatively small sample size of this study.

Acute Basilar Artery Occlusion: Differences in Characteristics and Outcomes after Endovascular Therapy between Patients with and without Underlying Severe Atherosclerotic Stenosis.

BACKGROUND AND PURPOSE: Prediction of underlying intracranial atherosclerotic stenosis before endovascular therapy might be helpful for appropriate therapeutic planning in patients with acute ischemic stroke. This study aimed to compare the characteristics and treatment outcomes in patients with acute basilar artery occlusion relative to the existence or nonexistence of underlying intracranial atherosclerotic stenosis. MATERIALS AND METHODS: Sixty-two patients with acute basilar artery occlusion underwent multimodal endovascular therapy. All patients underwent stent-retriever thrombectomy as a first-line endovascular therapy. Patients with underlying intracranial atherosclerotic stenosis underwent additional intracranial angioplasty and stent placement. The clinical and imaging characteristics and treatment outcomes were retrospectively analyzed and compared between patients with and without intracranial atherosclerotic stenosis. RESULTS: Underlying intracranial atherosclerotic stenosis was identified at the occlusion site in 15 patients (24.1%). Occlusion in the proximal segment of the basilar artery was more common in patients with intracranial atherosclerotic stenosis (60% versus 6.4%, P < .001), whereas occlusion in the distal segment was more common in those without it (91.5% versus 26.7%, P < .001). Bilateral thalamic infarction on a pretreatment DWI was less common in patients with intracranial atherosclerotic stenosis (0% versus 27.7%, P = .027) compared with those without it. There were no significant differences in the rates of successful revascularization, favorable outcome, symptomatic hemorrhage, and mortality between the 2 groups. CONCLUSIONS: Underlying intracranial atherosclerotic stenosis was not uncommon in patients with acute basilar artery occlusion. The occlusion segment of the basilar artery and the presence or absence of bilateral thalamic infarction on a pretreatment DWI might be helpful for predicting underlying intracranial atherosclerotic stenosis in patients with acute basilar artery occlusion. Patients with and without underlying intracranial atherosclerotic stenosis who underwent endovascular therapy had similar outcomes.

Deformation mechanisms to ameliorate the mechanical properties of novel TRIP/TWIP Co-Cr-Mo-(Cu) ultrafine eutectic alloys.

In the present study, the microstructural evolution and the modulation of the mechanical properties have been investigated for a Co-Cr-Mo (CCM) ternary eutectic alloy by addition of a small amount of copper (0.5 and 1 at.%). The microstructural observations reveal a distinct dissimilarity in the eutectic structure such as a broken lamellar structure and a well-aligned lamellar structure and an increasing volume fraction of Co lamellae as increasing amount of copper addition. This microstructural evolution leads to improved plasticity from 1% to 10% without the typical tradeoff between the overall strength and compressive plasticity. Moreover, investigation of the fractured samples indicates that the CCMCu alloy exhibits higher plastic deformability and combinatorial mechanisms for improved plastic behavior. The improved plasticity of CCMCu alloys originates from several deformation mechanisms; i) slip, ii) deformation twinning, iii) strain-induced transformation and iv) shear banding. These results reveal that the mechanical properties of eutectic alloys in the Co-Cr-Mo system can be ameliorated by micro-alloying such as Cu addition.