bluuebunny/crossref_metadata_2025 huggingface dataset:
Influences of Nd doping on preparing Mg2 Si semiconductor thin films by thermal evaporation
Authors: Yu Hong , Luo Yuee , Wang Xuewen , He Yi , Xu Lin , Sun Liping , Liao Lijun , Deng Rui
Published: March 2019

In this work, the thermal evaporation method was adopted to prepare Nd‐doped Mg2 Si semiconductor thin films on n‐Si(111) substrate. The structure, morphology and optical properties of these Mg2 Si thin films doped with Nd were studied by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Raman spectroscopy (RAMAN). The XRD results showed that Nd dopant led to weakened Mg2 Si diffraction peaks and bigger lattice constants. The scanning electron microscopy results indicated decreased size of Mg2 Si grains and clusters formed by the grains because of Nd dopant. The RAMAN results showed that the intensity of the characteristic peaks near 256 and 690 cm−1 decreased due to the influence of Nd doping.
Investigations on performance of valveless piezoelectric micropump with concave tuning diffuser/nozzle elements in transient flow
Authors: He Xiuhua , Shi Jiawei , Yang Hang , Lin Nan , Uzoejinwa Benjamin Bernard
Published: March 2019

A diffuser/nozzle is one of the most frequently‐used channels in a valveless piezoelectric micropump, but its efficiency has not been satisfactory. Hence, optimisation of the channel structure is of great significance. The concave tuning diffuser/nozzle element can obtain steady flow rectification under different Reynolds numbers, and its efficiency is much higher than the conventional diffuser/nozzle element whose diverging angle is >25°. Therefore, the application of concave tuning on the micropump is promising and worth anticipating. In this work, the experiment and numerical simulation were carried out under the conditions of voltage (50–250 vpp), excitation frequency (10–1000 Hz) and Rec (100–1000). The results show that the performance of a micropump with concave tuning is better than that with a straight sidewall, as the pump efficiency is improved significantly. The position and size of vortexes are of great significance to the pump efficiency of the micropumps. The distribution of pressure in the micropumps with concave tuning and straight sidewall was displayed. With the increase of characteristic Reynolds number, the adverse pressure gradient occurred. Compared with the straight sidewall, the concave tuning structure can better withstand adverse pressure gradient and delay the boundary layer separation in the channel.
Detection of spike-like structures near the front of type-II bursts
Authors: Armatas S. , Bouratzis C. , Hillaris A. , Alissandrakis C. E. , Preka-Papadema P. , Moussas X. , Mitsakou E. , Tsitsipis P. , Kontogeorgos A.
Published: March 2019

Aims. We examine high time resolution dynamic spectra for fine structures in type II solar radio bursts

Methods. We used data obtained with the acousto-optic spectrograph receiver of the Artemis-JLS (ARTEMIS-IV) solar radio spectrograph in the 450–270 MHz range at 10 ms cadence and identified more than 600 short, narrowband features. Their characteristics, such as instantaneous relative bandwidth and total duration were measured and compared with those of spikes embedded in type IV emissions.

Results. Type II associated spikes occur mostly in chains inside or close to the slowly drifting type II emission. These spikes coexist with herringbone and pulsating structures. Their average duration is 96 ms and their average relative bandwidth 1.7%. These properties are not different from those of type IV embedded spikes. It is therefore possible that they are signatures of small-scale reconnection along the type II shock front.
Variant impatient behavior of a Markovian queue with balking reserved idle time and working vacation
Authors: Azhagappan Arumugam , Deepa Thirunavukkarasu
Published: March 2019

The customers’ impatience and its effect plays a major role in the economy of a country. It directly affects the sales of products and profit of a trading company. So, it is very important to study various impatient behaviors of customers and to analyze different strategies to hold such impatient customers. This situation is modeled mathematically in this research work along with working vacation and reserved idle time of server, balking and re-service of customers. This paper studies the transient analysis of anM/M/1 queueing model with variant impatient behavior, balking, re-service, reserved idle time and working vacation. Whenever the system becomes empty, the server resumes working vacation. When he is coming back from the working vacation and finding the empty system, he stays idle for a fixed time period known as reserved idle time and waits for an arrival. If an arrival occurs before the completion of reserved idle time, the server starts a busy period. Otherwise, he resumes another working vacation after the completion of reserved idle time. During working vacation, the arriving customers may either join or balk the queue. The customers waiting in the queue for service, during working vacation period, become impatient. But, the customer who is receiving the service in the slow service rate, does not become impatient. After each service, the customer may demand for immediate re-service. The transient system size probabilities for the proposed model are derived using generating function and continued fraction. The time-dependent mean and variance of system size are also obtained. Finally, numerical illustrations are provided to visualize the impact of various system parameters.
Magnesium Lithospermate B Derived from Salvia miltiorrhiza Ameliorates Right Ventricle Remodeling in Pulmonary Hypertensive Rats via Inhibition of NOX/VPO1 Pathway
Authors: Li Tao , Peng Jing-Jie , Wang E-Li , Li Nian-Sheng , Song Feng-Lin , Yang Jin-Fu , Luo Xiu-Ju , Liu Bin , Peng Jun
Published: March 2019

Right ventricle (RV) remodeling is a major pathological feature in pulmonary arterial hypertension (PAH). Magnesium lithospermate B (MLB) is a compound isolated from the roots of Salvia miltiorrhiza and it possesses multiple pharmacological activities such as anti-inflammation and antioxidation. This study aims to investigate whether MLB is able to prevent RV remodeling in PAH and the underlying mechanisms. In vivo, SD rats were exposed to 10% O2 for 21 d to induce RV remodeling, which showed hypertrophic features (increases in the ratio of RV weight to tibia length, cellular size, and hypertrophic marker expression), accompanied by upregulation in expression of NADPH oxidases (NOX2 and NOX4) and vascular peroxidase 1 (VPO1), increases in hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) production and elevation in phosphorylation levels of ERK; these changes were attenuated by treating rats with MLB. In vitro, the cultured H9c2 cells were exposed to 3% O2 for 24 h to induce hypertrophy, which showed hypertrophic features (increases in cellular size and hypertrophic marker expression). Administration of MLB or VAS2870 (a positive control for NOX inhibitor) could prevent cardiomyocyte hypertrophy concomitant with decreases in NOX (NOX2 and NOX4) and VPO1 expression, H2O2 and HOCl production, and ERK phosphorylation. Based on these observations, we conclude that MLB is able to prevent RV remodeling in hypoxic PAH rats through a mechanism involving a suppression of NOX/VPO1 pathway as well as ERK signaling pathway. MLB may possess the potential clinical value for PAH therapy.
Electrochemical C(sp3)–H Fluorination
Authors: Takahira Yusuke , Chen Miao , Kawamata Yu , Mykhailiuk Pavel , Nakamura Hugh , Peters Byron K. , Reisberg Solomon H. , Li Chao , Chen Longrui , Hoshikawa Tamaki , Shibuguchi Tomoyuki , Baran Phil S.
Published: March 2019

A simple and robust method for electrochemical alkyl C–H fluorination is presented. Using a simple nitrate additive, a widely available fluorine source (Selectfluor), and carbon-based electrodes, a wide variety of activated and unactivated C–H bonds are converted into their C–F congeners. The scalability of the reaction is also demonstrated with a 100 gram preparation of fluorovaline.
Anatomical Revelations in 1921 Kindled Operative Repair of the Orbit, Eyelids, and Periorbit over the Ensuing 100 Years: The Diuturnity of Ernest Whitnall (1876–1950) of Oxford, Montreal, and Bristol
Authors: Pollock Richard A. , Gossman M.Douglas
Published: March 2019

Revelations of orbital, intraorbital, and periorbital anatomy by a single author in 1921 kindled attempts at operative repair of the orbit, eyelids, and periorbit over the ensuing 100 years. They are the lasting contributions—the diuturnity—of Samuel Ernest Whitnall (1876–1950) of Oxford, Montreal, and Bristol.
Cementless Primary Total Hip Arthroplasty with a Trabecular Titanium Implant: Results at Short-to-Medium-Term Follow-Up
Authors: Bertagnon Andrea , Celotti Luca , D'Angelo Fabio , Harwin Steven , Vulcano Ettore , Surace Michele
Published: March 2019

Over the last two decades, cementless hip prostheses gained increasing popularity. Highly porous, trabecular coatings and their promising bone-friendly properties also came to a wider diffusion. As a consequence, this study was aimed to evaluate clinical and radiographic results at short-to-medium term of cementless prosthetic implants with trabecular titanium cup and titanium femoral metaphyseal stem highly porous coatings. From September 2012 to June 2015 213, cementless total hip arthroplasties were performed in 200 patients. All patients received a cementless Accolade II stem and Tritanium cup with UHMWPE Trident X3 Bearing Technology polyethylene liner. All surgeries were performed using a tissue-sparing modified posterolateral approach. All patients underwent prophylaxis for heterotopic ossifications. For every patient, the following data were collected: age, gender, height, weight, body mass index, blood loss, preoperative and postoperative hemoglobin, surgical time, and complications. Harris Hip Score was obtained for every patient. Radiographic measurements were performed using a freeware software (TraumaCAD 2.0). The computed parameters were inclination and anteversion of acetabular cup and presence of heterotopic ossification. The mean follow-up was 37.7 months from surgery. Data were analyzed by SPSS software v 24.0. The postoperative average Harris Hip Score was 87.4 points (range, 40.5–95.7) and 91 patients scored excellent results, with more than 90 points (52.4%). Heterotopic ossifications were seen in 12 patients (6.9%) and correlated to patient weight, surgical timing, and hemoglobin values. There were three cases of dislocation (1.7%) that significantly correlated with cup inclination (R
2 = 17.9; p = 0.018). One cup underwent early revision because of undersizing of the component and subsequent lack of integration, thus leading to an overall survivorship of 99.4%. In conclusion, excellent medium-term functional outcome, patient satisfaction, and low complications rate were observed for the studied implant. A higher incidence of heterotopic ossifications was significantly correlated to patient weight, surgical time, blood loss, and transfusions. Also, inclination of the acetabular cup proved to be correlated to hip dislocation.
Systematic Review of Hearing Preservation in Observed Vestibular Schwannoma
Authors: Reznitsky Martin , Cayé-Thomasen Per
Published: March 2019

Objective This is a systematic review of the literature on the spontaneous course of hearing in patients observed with a vestibular schwannoma. Included studies are appraised using the Grading of Recommendations Assessment, Development and Evaluation system.

Design PubMed, Embase, Medline, Cochrane library, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) were searched for literature on hearing in patients observed with a vestibular schwannoma.

Participants Of 217 evaluated papers, 15 were included, representing a total of 2,142 patients.

Main Outcome Measures Hearing according to the AAO-HNS (American Academy of Otorhinolaryngology- Head and Neck Surgery) classification system. Weighted average of the proportion of patients preserving good hearing (>70% discrimination score and pure tone audiometry [PTA] < 30dB) and serviceable hearing (>50% discrimination score and PTA < 50dB) was determined.

Results Fifty percent of patients presenting with good hearing at diagnosis had preserved this after a mean of 5 years of observation, whereas serviceable hearing was preserved in 54%. Patients with normal discrimination at diagnosis preserve their hearing very well. Very few studies exist on long-term hearing preservation.

Conclusions After 5 years of observation, around half of patients will have preserved good or serviceable hearing. Patients with normal discrimination at diagnosis are more likely to preserve good hearing.
Intentional Subtotal Resection of Vestibular Schwannoma: A Reexamination
Authors: Strickland Ben A. , Ravina Kristine , Rennert Robert C. , Jackanich Anna , Aaron Ksenia , Bakhsheshian Joshua , Russin Jonathan J. , Friedman Rick A. , Giannotta Steven L.
Published: March 2019

Background Treatment of vestibular schwannomas (VS) remains controversial. Historical surgical series prioritized gross total resections (GTR); however, near total resections (NTR) and intentional subtotal resections (STR) aiming at improving cranial nerve outcomes are becoming more popular.

Objective The main purpose of this article is to assess the tumor control and facial nerve outcomes in VS patients treated with STR or NTR.

Methods VS patients undergoing STR or NTR at our institution between 1984 and 2016 were retrospectively reviewed. Patient demographics, extent of tumor resection, facial nerve injury, tumor recurrence, and need for Gamma Knife radiosurgery were analyzed. Facial nerve outcomes were quantified using House–Brackmann (HB) scores. Tumor regrowth was defined by the San Francisco criteria.

Results Four-hundred fifty-seven VS resections were performed in a 32-year period. Sixty cases met inclusion criteria. The mean (range) follow-up duration was 30.9 (12–103) months. The STR cohort (n = 33) demonstrated regrowth in 12 patients (36.3%) at an average of 23.6 months. The NTR cohort (n = 27) did not experience tumor recurrence. Risk of tumor recurrence was positively correlated with preoperative tumor size (p = 0.002), size of residual tumor (p < 0.001), and STR (p < 0.001). Facial nerve outcomes of HB1–2 were observed in the majority of patients in both cohorts (74.1% NTR, 56% STR), though NTR was associated with a higher likelihood of facial nerve recovery (p = 0.003).

Conclusion GTR remains the gold standard as long as facial nerve outcomes remain acceptable. NTR achieved superior tumor control and higher likelihood of facial nerve recovery compared with STR.
Long-Term Effectiveness of Antireflux Surgery in Esophageal Atresia Patients
Authors: Jönsson Linus , Dellenmark-Blom Michaela , Enoksson Oskar , Friberg Lars Göran , Gatzinsky Vladimir , Sandin Anders , Abrahamsson Kate
Published: March 2019

Introduction Gastroesophageal reflux disease (GERD) is a common morbidity after esophageal atresia (EA) repair, and the antireflux procedure (ARP) is a way of treating GERD symptoms. The aim of this study was to evaluate whether reflux index (Ri) and growth were improved by ARP.

Materials and Methods Ninety-nine individuals with EA treated at the Queen Silvia Children's Hospital in Gothenburg, Sweden, between 1997 and 2010 were followed prospectively according to a structured care program. Twenty-four-hour pH-metry (Ri) and growth were studied at birth, then at 1, 7, and 15 years of age. All the patients included had reached 7 years of age.

Results Preoperatively, Ri was significantly higher (32%) in the ARP than the non-ARP group (10%). Postoperatively, no difference was seen between the groups. However, at 7 and 15 years of age, Ri was significantly higher in the ARP group than in the non-ARP group. Weight (standard deviation scores) was significantly lower in the ARP group at 1 and 7 years of age when compared with the non-ARP group, but these differences were not seen at birth and at 15 years of age. In a multivariate analysis, only birth weight remained a significant factor for low weight at 7 years of age. At 15 years of age, no risk factors for low body weight were found.

Conclusion In the long term, ARP is not effective in reducing GERD as measured as Ri in EA patients. The ARP group had significantly lower weight at 1 and 7 years of age than the non-ARP group, but this was not the case at the age of 15.
The Outcome of the Single Step Questionnaire in Pectus Excavatum Patients is Phase Dependent
Authors: Zuidema Wietse P. , van der Steeg Alida F. W. , van der Heide Stefan , Zijp Gerda W. , van Baren Robertine , Oosterhuis Jan W. A. , van Heurn Ernest
Published: March 2019

Introduction Pectus excavatum (PE) is the most common chest wall deformity. Patients with PE may have cosmetic complaints, restricted physical capabilities, or both and may seek surgical correction. One method to assess satisfaction after surgery is the single step questionnaire (SSQ). Although the developers state that the SSQ produces a stabile score and only needs to be used once, we hypothesized that the score may depend on point in time after surgery.

Materials and Methods One hundred and eight patients from a longitudinal cohort of patients undergoing a Nuss bar placement for PE were selected. Mean age was 16.0 years (range: 12–29). SSQ was completed at 6 weeks, 6 months, 1 year, and 2 years postoperatively. Mean and median scores per question and total scores were calculated on each measurement moment. Overall scores were tested using the Friedman test.

Results There were significant differences in overall SSQ scores (p < 0.009) throughout the postoperative period, especially between 6 weeks and 6 months (p = 0.006). Scores on general health, exercise capacity, impact on social life, pain during hospital stay, and after discharge changed also significant in the first 2 years after Nuss bar placement.

Conclusion There were significant differences in total SSQ score depending on the time of application postoperatively. However, the most clinical relevant difference was between 6 weeks and 6 months. Assessment of the overall satisfaction postoperative with the SSQ questionnaire should not be done with a single measurement but rather at different postoperative time intervals before and after 6 months postoperatively.
Obesity Is Associated with Significant Morbidity after Multiligament Knee Surgery
Authors: Lian Jayson , Patel Neel K. , Nickoli Michael , Vaswani Ravi , Irrgang James J. , Lesniak Bryson P. , Musahl Volker
Published: March 2019

The objective was to report the effect of obesity, utilizing a body mass index (BMI) threshold of 35 kg/m2, on outcomes and complications of multiple ligament knee injury (MLKI). It was hypothesized that obese patients would have longer intraoperative times and hospital length of stay, greater estimated blood loss, and higher rates of wound infection requiring irrigation and debridement (I&D) and revision ligament surgery. A retrospective review was performed on 143 individuals who underwent surgery for an MLKI between 2011 and 2018 at a single academic center. Patients were included if there was a plan for potential surgical repair/reconstruction of two or more ligaments. Patients with prior surgery to the affected knee or intra-articular fracture requiring reduction and fixation were excluded. Comparisons between obese and nonobese patients were made using two-sample t-test and either chi-square or Fisher's exact test for continuous and categorical variables, respectively. Significance was set at p < 0.05. Of 108 patients meeting inclusion criteria, 83 had BMI < 35 kg/m2 and 25 had BMI ≥ 35 kg/m2. Obese patients sustained higher rates of MLKI due to ultralow velocity mechanisms (28.0 vs. 1.2%; p = 0.0001) and higher rates of concomitant lateral meniscus injury (48.0 vs. 25.3%; p = 0.04). Among patients undergoing single-staged surgery, obese patients had significantly longer duration of surgery (219.8 vs. 178.6 minutes; p = 0.02) and more wound infections requiring I&D (20.0 vs. 4.8%; p = 0.03). In contrast, nonobese patients had higher rates of arthrofibrosis requiring manipulation under anesthesia and/or arthrolysis (25.3 vs. 0%; p = 0.003). Obese patients undergoing surgery of an MLKI have longer operative times, greater rates of wound infection requiring I&D, and lower rates of arthrofibrosis. Surgeons may consider these results when counseling patients on their postoperative course and risk for complications. Future research might focus on strategies to reduce complication rates in obese patients with MLKI. This is a Level III, retrospective comparative study.
Arthroscopic Posterior Cruciate Ligament Reconstruction: The Achilles Tendon Allograft versus the Quadriceps Tendon Allograft
Authors: Kang Seung Hoon , Sohn Kang Min , Lee Do Kyung , Lee Byung Hoon , Yang Seong Wook , Wang Joon Ho
Published: March 2019

We aimed to compare and analyze the outcomes of arthroscopic posterior cruciate ligament (PCL) reconstruction with the Achilles tendon allograft and the quadriceps tendon allograft. Twenty-nine patients who received the same procedure of arthroscopic PCL reconstruction within our inclusion criteria were reviewed retrospectively. There were 13 patients in the Achilles tendon allograft group and 16 patients in the quadriceps tendon allograft group. At least in 2 years of follow-up period, we evaluated the patients using the posterior drawer test, KT 2000 test, Lysholm knee scoring scale, Tegner activity scale score, International Knee Documentation Committee (IKDC) subjective knee form score, and Telos stress radiography. Between the two groups, no differences were found in preoperative patient demographic factors (age, gender, mean time of surgery, average follow-up period, cause of injury, and combined injury) (p > 0.05). Results of the posterior drawer test, KT 2000 test, Telos stress radiography, Lysholm score, Tegner activity score, and IKDC subjective score were not significantly different between the two groups at preoperative evaluation and after surgery (p > 0.05). On comparing preoperative evaluation and follow-up after surgery, the Achilles tendon allograft group showed significant improvement in the results of the KT 2000 test, Telos stress radiology, and Lysholm score, whereas the quadriceps tendon allograft group showed significant improvement in the results of the KT 2000 test, Telos stress radiology, Lysholm score, Tegner activity score, and IKDC subjective score (p < 0.05). The quadriceps tendon for arthroscopic PCL reconstruction is good alternative allograft for the Achilles tendon for arthroscopic PCL reconstruction. This is a retrospective comparative study.
A Cam–Post Mechanism Is No Longer Necessary in Modern Primary Total Knee Arthroplasty
Authors: Meneghini R. Michael , Stefl Michael D. , Hodge W. Andrew , Banks Scott A.
Published: March 2019

Conclusive evidence supporting a clinical difference between posterior-stabilized (PS) and cruciate-retaining (CR) designs in total knee arthroplasty (TKA) does not currently exist, despite both designs being used for decades. Proponents of PS designs that employ a cam-and-post mechanism cite in vivo fluoroscopic data that demonstrate improved posterior rollback; however, optimal rollback has never been correlated to superior clinical outcomes. Recently, anterior-lipped and more conforming CR bearings, such as ultracongruent, medial pivot, and dual-pivot designs, have been used to substitute for the posterior cruciate ligament and obviate the need for the cam–post mechanism of a traditional PS design. Advantages of avoiding a PS TKA include eliminating the risk of box cut induced femoral condylar fracture, improving operative efficiency by removing procedural steps, removing the articulation that is a source of wear, postdeformation, breakage, or dislocation, and eliminating patellar clunk. Health care reform efforts mandate cost reduction, and procedural efficiencies and minimizing inventory through the removal of unnecessary bearing options foster that initiative.
Tourniquet Use in Total Knee Arthroplasty
Authors: Arthur Jaymeson R. , Spangehl Mark J.
Published: March 2019

Tourniquet use in total knee arthroplasty has become a controversial topic. There are several benefits of its use including improved visualization, decreased blood loss, shorter operative times, and improved antibiotic delivery. Conversely, there are several significant downsides associated with tourniquet use including postoperative pain, neuromuscular injuries, wound complications, reperfusion injury, increased risk of thrombosis, patellar tracking issues, delayed rehabilitation including decreased postoperative range of motion, and its negative effect on patients with vascular disease. However, objectively, the literature does not definitively push us toward or away from the use of a tourniquet. Furthermore, several alternatives have been developed to help mitigate some of the adverse effects associated with its use. This article summarizes the evidence for and against tourniquet use and provides an evidence-based approach to help guide surgeons in their own practice.
The Outcomes of Distal Femoral Varus Osteotomy in Patellofemoral Instability: A Systematic Review and Meta-Analysis
Authors: Tan Si Heng Sharon , Hui Si Jian , Doshi Chintan , Wong Keng Lin , Lim Andrew Kean Seng , Hui James Hoipo
Published: March 2019

Distal femoral varus osteotomies have been novelly described in the recent years to be successful in the management of patellofemoral instability with genu valgum. However, these publications are limited to case reports and small case series and no published literature have attempted to analyze them in totality. The current review aims to pool together these small case series to evaluate the outcomes and complications of distal varus femoral osteotomies when performed for patellofemoral instability. The review was conducted using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. All studies that reported the outcomes of distal femoral varus osteotomy for patellofemoral instability were included. A total of five publications were included in the review, which included a total of 73 patients. All of the studies reported improvement in the radiological outcomes for genu valgum correction and patellofemoral instability. One study using opening wedge osteotomy reported a decrease in Caton–Deschamps index postoperatively, while another study using closing wedge osteotomy reported maintenance of the Caton–Deschamps index postoperatively. Second look arthroscopy showed an improvement in the status of the chondral lesions of the medial facet of the patellar undersurface, the lateral facet of the patellar undersurface and the trochlear groove 2 years postoperatively. All studies also reported a decrease in the risk of recurrence of patellofemoral instability, reduction in pain, and an improvement in all the clinical outcomes knee scores. Distal femoral varus osteotomy is promising and useful in the management of patellofemoral instability with genu valgum. The procedure can allow for radiological correction of the genu valgum and patellofemoral instability, reduction in the risk of recurrence of patellofemoral instability, reduction in pain, improvement in clinical knee outcome scores, and improvement in the status of the chondral lesions in the patellofemoral joint. It is highly versatile and could accommodate varying degrees of correction. These improvements in radiological and clinical outcomes can be seen in studies for both closing wedge and opening wedge distal femoral osteotomies. However, opening wedge osteotomies appear to decrease the patellar height as compared with closing wedge osteotomies which maintain the patellar height; therefore, the patellar height should be assessed preoperatively prior to deciding whether to perform an opening wedge or closing wedge distal femoral varus osteotomy. The Level of Evidence for this study is IV.
Relative Incidence of Proximal Fibula Fractures with Tibial Plateau Fractures: An Investigation of 354 Cases
Authors: Liu Yue , Zhang Yan , Liang Xu , Shao Jin , Ai Zisheng , Yang Tieyi
Published: March 2019

We aimed to investigate the incidence of proximal fibula fractures in patients with tibial plateau fractures and to identify risk factors for such combined injuries. From January 2011 to December 2015, 354 patients with tibial plateau fractures who had been admitted to a level 1 trauma center were retrospectively evaluated by an orthopaedic trauma surgeon and two skeletal radiologists. Anteroposterior plain radiography and computed tomography (CT) were used to characterize the injuries, and the incidence of associated proximal fibula fractures was determined. The tibial plateau fractures were classified according to the Schatzker's and three-column classifications. Associated proximal fibula fractures were simultaneously classified with a new fibula fracture classification system. Finally, we determined whether there were statistically significant associations between the presence of a proximal fibula fracture and different types of tibial plateau fractures, as well as sex and age. Proximal fibula fractures were detected in 192 (54.24%) patients using plain radiography and in 215 (60.73%) patients using CT. Logistic regression analysis indicated an increasing trend in the incidence of fibula fractures detected by the CT-based three-column classification system as follows: “age × sex > three columns > age > single posterior column > lateral column + posterior column > medial column + posterior column > medial column + lateral column > single lateral column > single medial column.” Proximal fibula fracture associated with tibial plateau fracture is a common phenomenon worthy of attention. In women, age increases the likelihood of complex tibial plateau fractures, particularly those involving the posterolateral articular surface and diaphysis, as well as the likelihood of developing proximal fibula fractures. This s Level IV diagnostic study.
Disparate Rates of Cesarean Delivery in Term Nulliparous Women with Hypertensive Disorders of Pregnancy
Authors: Penfield Christina A. , Nageotte Michael P. , Wing Deborah A.
Published: March 2019

Objective To evaluate the prevalence of cesarean delivery in women with hypertensive disorders of pregnancy (HDP), and explore whether maternal, sociodemographic, or obstetric comorbidities contribute to cesarean delivery rates.

Study Design This is a retrospective cohort study of nulliparous, term, singleton, vertex women using the 2013 U.S. National Vital Statistics Report. We compared prevalence of risk factors for cesarean delivery between women with and without HDP, and then calculated probabilities of cesarean delivery after controlling for these risk factors.

Results In this cohort of 1,439,977 women, the unadjusted probability of cesarean delivery in women with HDP was 39.5 versus 26.8% in those without the diagnosis (p < 0.01). Hypertensive women had more risk factors for cesarean delivery, most notably morbid obesity (9.0 vs. 3.1%, p < 0.01), diabetes (9.9 vs. 4.4%, p < 0.01), and induction of labor (59.2 vs. 26.9%, p < 0.01). Despite this, after controlling for these risk factors, hypertensive women remained significantly more likely to undergo cesarean delivery (35.1 vs. 26.4%, p < 0.01).

Conclusion Even after controlling for multiple comorbidities, hypertension remained a significant risk factor for cesarean delivery in nulliparous women at term. Hypertensive women may therefore represent an important target population in efforts aimed at reduction of cesarean rates.
Task-driven visual exploration at the foveal scale
Authors: Shelchkova Natalya , Tang Christie , Poletti Martina
Published: March 2019

Humans use saccades to inspect objects of interest with the foveola, the small region of the retina with highest acuity. This process of visual exploration is normally studied over large scenes. However, in everyday tasks, the stimulus within the foveola is complex, and the need for visual exploration may extend to this smaller scale. We have previously shown that fixational eye movements, in particular microsaccades, play an important role in fine spatial vision. Here, we investigate whether task-driven visual exploration occurs during the fixation pauses in between large saccades. Observers judged the expression of faces covering approximately 1°, as if viewed from a distance of many meters. We use a custom system for accurately localizing the line of sight and continually track gaze position at high resolution. Our findings reveal that active spatial exploration, a process driven by the goals of the task, takes place at the foveal scale. The scanning strategies used at this scale resemble those used when examining larger scenes, with idiosyncrasies maintained across spatial scales. These findings suggest that the visual system possesses not only a coarser priority map of the extrafoveal space to guide saccades, but also a finer-grained priority map that is used to guide microsaccades once the region of interest is foveated.
Investigation into the mechanism of thin filament regulation by transient kinetics and equilibrium binding: Is there a conflict?
Authors: Heeley David H. , White Howard D. , Taylor Edwin W.
Published: March 2019

Striated muscle contraction occurs when myosin undergoes a lever-type structural change. This process (the power stroke) requires ATP and is governed by the thin filament, a complex of actin, tropomyosin, and troponin. The authors have used a fast-mixing instrument to investigate the mechanism of regulation. Such (pre–steady-state kinetic) experiments allow biochemical intermediates in a working actomyosin cycle to be monitored. The regulatory focal point is demonstrated to be the step that involves the departure of inorganic phosphate (i.e., AM-ADP-Pi → AM-ADP). This part of the cycle, which lies on the main kinetic pathway and coincides with the drive stroke, is maximally accelerated ∼100-fold by the combined association of ligands (Ca[II] and rigor myosin heads) with the thin filament. However, the observed ligand dependencies of the rates of Pi dissociation that are reported herein are at variance with predictions of models derived from experiments where ATP hydrolysis is not taking place (and myosin exists in a nonphysiological form). It is concluded that the principal influence of the thin filament is in setting the rate of Pi dissociation and that physiological levels of regulation are dependent upon the liganded state of the thin filament as well as the conformation of myosin.
Context-dependent strategies of food allocation among offspring in a facultative cooperative breeder
Authors: Li Jianqiang , Wang Yong , Lv Lei , Wang Pengcheng , Hatchwell Ben J , Zhang Zhengwang
Published: March 2019

Natural selection should favor adoption of parental strategies that maximize fitness when allocating investment among offspring. In birds, begging displays often convey information of nestling need and quality, allowing parents to make adaptive food allocation decisions. We investigated how adults utilized cues likely to represent nestling competitive ability (begging position) and need (begging intensity) and a cue independent of nestling control (nestling sex) to distribute food among nestlings in a facultative cooperative breeder, the black-throated tit (Aegithalos concinnus). We found that parents reduced their efforts when helped, suggesting that parents of helped broods would have the potential to satisfy nestling needs more than unhelped parents. This suggestion was supported by the fact that nestling mass increased faster in helped than in unhelped nests. We found no effect of nestling sex on food allocation, but, as predicted, we found that adults responded differently to begging signals in relation to the presence of helpers and brood size. First, helped parents were more responsive to nestling begging intensity than parents without helpers. Second, female parents and helpers had a stronger preference for nestling begging position in large than in small broods. Third, the preference for nestling begging position was greater for unhelped than for helped female parents. These results provide evidence that carers adjust their preference for different offspring begging signals based on availability of food resources.
aphid: an R package for analysis with profile hidden Markov models
Authors: Wilkinson Shaun P
Published: March 2019

Hidden Markov models (HMMs) and profile HMMs form an integral part of biological sequence analysis, supporting an ever-growing list of applications. The aphid R package can be used to derive, train, plot, import and export HMMs and profile HMMs in the R environment. Computationally-intensive dynamic programing recursions, such as the Viterbi, forward and backward algorithms are implemented in C++ and parallelized for increased speed and efficiency.

Availability and implementation

The aphid package is released under the GPL-3 license, and is freely available for download from CRAN and GitHub (https://github.com/shaunpwilkinson/aphid).

Supplementary information

Supplementary data are available at Bioinformatics online.
Wind energy in Brazil: an overview and perspectives under the triple bottom line
Authors: Lucena Juliana de Almeida Yanaguizawa , Lucena Klayton Ângelo Azevedo
Published: March 2019

In recent years, Brazilian wind energy has been growing on a fast trajectory, with the prospect of being the second main source of energy in the year 2019 after hydroelectricity. It should be reaching an installed capacity of more than 20 GW by 2022. In this context, this work presents the evolution and the current scenario of wind energy in Brazil, bringing a discussion on the issues surrounding wind energy and the environmental, social and economic pillars of the sustainability. This study highlights the Northeast region because it has more than 85% of the wind capacity in the country and, at the same time, it contains the cities with the lowest human development indexes. Rotor-blade manufacturing methods and composite materials recycling after the turbine lifetime are considered. Construction, operation and maintenance aspects of wind turbines are also discussed. Wind-energy concepts are described from a bibliographic survey and previous experiences of the authors.
Sialyltransferase7A promotes angiotensin II-induced cardiomyocyte hypertrophy via HIF-1α-TAK1 signalling pathway
Authors: Yan Xiaoying , Zhao Ran , Feng Xiaorong , Mu Jingzhou , Li Ying , Chen Yue , Li Chunmei , Yao Qiying , Cai Lijie , Jin Lingling , Han Chuanchun , Zhang Dongmei
Published: March 2019

Aims

Sialylation is up-regulated during the development of cardiac hypertrophy. Sialyltransferase7A (Siat7A) mRNA is consistently over-expressed in the hypertrophic left ventricle of hypertensive rats independently of genetic background. The aims of this study were: (i) to detect the Siat7A protein levels and its roles in the pathological cardiomyocyte hypertrophy; (ii) to elucidate the effect of sialylation mediated by Siat7A on the transforming-growth-factor-β-activated kinase (TAK1) expression and activity in cardiomyocyte hypertrophy; and (iii) to clarify hypoxia-inducible factor 1 (HIF-1) expression was regulated by Siat7A and transactivated TAK1 expression in cardiomyocyte hypertrophy.

Methods and results

Siat7A protein level was increased in hypertrophic cardiomyocytes of human and rats subjected to chronic infusion of angiotensin II (ANG II). Delivery of adeno-associated viral (AAV9) bearing shRNA against rat Siat7A into the left ventricular wall inhibited ventricular hypertrophy. Cardiac-specific Siat7A overexpression via intravenous injection of an AAV9 vector encoding Siat7A under the cardiac troponin T (cTNT) promoter aggravated cardiac hypertrophy in ANG II-treated rats. In vitro, Siat7A knockdown inhibited the induction of Sialyl-Tn (sTn) antigen and cardiomyocyte hypertrophy stimulated by ANG II. Mechanistically, ANG II induced the activation of TAK1-nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signalling in parallel to up-regulation of Siat7A in hypertrophic cardiomyocytes. Siat7A knockdown inhibited activation of TAK1-NF-κB pathway. Interestingly, HIF-1α expression was increased in cardiomyocytes stimulated by ANG II but decreased after Siat7A knockdown. HIF-1α knockdown efficiently decreased TAK1 expression. ChIP and luciferase assays showed that HIF-1α transactivated the TAK1 promoter region (nt −1285 to −1274 bp) in the cardiomyocytes following ANG II stimulus.

Conclusion

Siat7A was up-regulated in hypertrophic myocardium and promoted cardiomyocyte hypertrophy via activation of the HIF-1α-TAK1-NF-κB pathway.
Surgery-first treatment improves clinical results in infective endocarditis complicated with disseminated intravascular coagulation†
Authors: Yokoyama Junya , Yoshioka Daisuke , Toda Koichi , Matsuura Ryohei , Suzuki Kota , Samura Takaaki , Miyagawa Shigeru , Yoshikawa Yasushi , Takano Hiroshi , Matsumiya Goro , Sakaguchi Taichi , Fukuda Hirotsugu , Takahashi Toshiki , Izutani Hironori , Funatsu Toshihiro , Nishi Hiroyuki ,   OSCAR Study Group, Sawa Yoshiki
Published: March 2019

OBJECTIVES:

Infective endocarditis (IE) is a critical infection with a high mortality rate, and it usually causes sepsis. Though disseminated intravascular coagulation (DIC) sometimes occurs in IE patients, no definitive treatment strategy for IE patients with DIC as a complication exists. Therefore, we evaluated the prevalence, surgical results and treatment strategy for IE complicated with DIC.

METHODS:

Between 2009 and 2017, a total of 585 patients undergoing valve surgery for active IE were enrolled at 14 institutions, of whom 116 (20%) had DIC as a complication. For further evaluation, we divided DIC patients into medical treatment-first (n = 45, group M) and valve surgery-first (n = 51, group S) groups after excluding 20 patients with intracranial haemorrhage.

RESULTS:

The overall survival rates at 1 and 5 years were 91% and 85% in the non-DIC group and 65% and 55% in the DIC group, respectively (P < 0.001). Recurrence-free survival rates at 1 and 5 years were 99% and 95% in the non-DIC group and 94% and 74% in the DIC group, respectively (P < 0.001). The overall survival rates at 1 and 5 years were 77% and 64% in group S and 51% and 46% in group M, respectively (P = 0.032). Multivariable analysis revealed that ‘medical treatment first’ was an exclusive independent risk factor [hazards ratio 2.26 (1.13–4.75), P = 0.024] for overall mortality.

CONCLUSIONS:

Mortality and IE recurrence were statistically significantly higher in DIC patients. Valve surgery should not be delayed because most patients proceeding with medical treatment eventually require emergency surgery and their clinical outcomes are worse than those of patients undergoing early surgery.
Clinical outcomes of paediatric patients supported by the Berlin Heart EXCOR: a systematic review
Authors: Rohde Sofie , Antonides Christiaan F J , Dalinghaus Michiel , Muslem Rahatullah , Bogers Ad J J C
Published: March 2019

Ventricular assist devices (VADs) are widely accepted as therapy to bridge children to heart transplantation. We provide a systematic review of the current state of clinical outcomes in children after paediatric VAD support by the Berlin Heart EXCOR (BH EXCOR) device. A systematic literature search was performed in April 2018. Studies reporting clinical outcomes in at least 15 children supported by a BH EXCOR VAD were included. Additionally, we focused on outcomes in small children and compared outcomes of children supported by a left ventricular assist device (LVAD) versus children supported by a biventricular assist device (BiVAD). Eighteen publications fulfilled the inclusion criteria and were included in this systematic review. Mortality rates ranged from 6.3% [confidence interval (CI) 0.0–18.1%] to 38.9% (2.8–75.0%) while transplantation rates ranged from 37.0% (CI 18.8–55.2%) to 72.5% (CI 63.9–81.2%) and successful weaning rates from 0.0% to 20.7% (CI 6.0–35.5%). In children under 1 year of age, mortality rates ranged from 20.0% to 55.5% and transplantation rates ranged from 0.0% to 62.5%. BiVAD support seemed to result in worse clinical outcomes than LVAD support. Incidence of stroke ranged from 5.0% to 47.0% in all children supported with the BH EXCOR. Although a high incidence of adverse events such as stroke and pump thrombosis is reported, VAD support should be considered in children with end-stage heart failure awaiting heart transplantation. Further research is warranted, especially on optimal timing of device implantation and anticoagulation regimens.
Impact of combined plaque structural stress and wall shear stress on coronary plaque progression, regression, and changes in composition
Authors: Costopoulos Charis , Timmins Lucas H , Huang Yuan , Hung Olivia Y , Molony David S , Brown Adam J , Davis Emily L , Teng Zhongzhao , Gillard Jonathan H , Samady Habib , Bennett Martin R
Published: March 2019

Aims

The focal distribution of atherosclerotic plaques suggests that local biomechanical factors may influence plaque development.

Methods and results

We studied 40 patients at baseline and over 12 months by virtual-histology intravascular ultrasound and bi-plane coronary angiography. We calculated plaque structural stress (PSS), defined as the mean of the maximum principal stress at the peri-luminal region, and wall shear stress (WSS), defined as the parallel frictional force exerted by blood flow on the endothelial surface, in areas undergoing progression or regression. Changes in plaque area, plaque burden (PB), necrotic core (NC), fibrous tissue (FT), fibrofatty tissue, and dense calcium were calculated for each co-registered frame. A total of 4029 co-registered frames were generated. In areas with progression, high PSS was associated with larger increases in NC and small increases in FT vs. low PSS (difference in ΔNC: 0.24 ± 0.06 mm2; P < 0.0001, difference in ΔFT: −0.15 ± 0.08 mm2; P = 0.049). In areas with regression, high PSS was associated with increased NC and decreased FT (difference in ΔNC: 0.15 ± 0.04; P = 0.0005, difference in ΔFT: −0.31 ± 0.06 mm2; P < 0.0001). Low WSS was associated with increased PB vs. high WSS in areas with progression (difference in ΔPB: 3.3 ± 0.4%; P < 0.001) with a similar pattern observed in areas with regression (difference in ΔPB: 1.2 ± 0.4%; P = 0.004). Plaque structural stress and WSS were largely independent of each other (R  2 = 0.002; P = 0.001).

Conclusion

Areas with high PSS are associated with compositional changes consistent with increased plaque vulnerability. Areas with low WSS are associated with more plaque growth in areas that progress and less plaque loss in areas that regress. The interplay of PSS and WSS may govern important changes in plaque size and composition.