bluuebunny/crossref_metadata_2025 huggingface dataset:
Ectomycorrhizal fungi mediate indirect effects of a bark beetle outbreak on secondary chemistry and establishment of pine seedlings
Authors: Karst Justine , Erbilgin Nadir , Pec Gregory J. , Cigan Paul W. , Najar Ahmed , Simard Suzanne W. , Cahill James F.
Published: June 2015

Dendroctonus ponderosae has killed millions of Pinus contorta in western North America with subsequent effects on stand conditions, including changes in light intensity, needle deposition, and the composition of fungal community mutualists, namely ectomycorrhizal fungi. It is unknown whether these changes in stand conditions will have cascading consequences for the next generation of pine seedlings.

To test for transgenerational cascades on pine seedlings, we tested the effects of fungal inoculum origin (beetle‐killed or undisturbed stands), light intensity and litter (origin and presence) on seedling secondary chemistry and growth in a glasshouse. We also tracked survival of seedlings over two growing seasons in the same stands from which fungi and litter were collected.

Fungal communities differed by inoculum origin. Seedlings grown with fungi collected from beetle‐killed stands had lower monoterpene concentrations and fewer monoterpene compounds present compared with seedlings grown with fungi collected from undisturbed stands. Litter affected neither monoterpenes nor seedling growth. Seedling survival in the field was lower in beetle‐killed than in undisturbed stands.

We demonstrate that stand mortality caused by prior beetle attacks of mature pines have cascading effects on seedling secondary chemistry, growth and survival, probably mediated through effects on below‐ground mutualisms.
A Systematic Review of Total Dislocation of the Talus
Authors: Weston John T. , Liu Xiaochen , Wandtke Meghan E , Liu Jiayong , Ebraheim Nabil E
Published: June 2015

This review summarizes the treatment and resulting outcomes for total talar dislocation. The PubMed database was searched for articles about humans with total talar dislocation published in the English language in the last twenty years. The following data were entered into a Microsoft Excel spreadsheet: type of dislocation, nature of associated fractures (if any), type of reduction/fixation utilized, immobilization, weight‐bearing status, outcome, complications and average follow‐up time. Thirty‐nine articles reporting a total of 86 cases of total talar dislocation are included in this review. Seventy‐three of these were open injuries and 13 closed. Forty‐three cases had an associated foot or ankle fracture, 32 of those cases specifically having a fracture of the talus. The talus was preserved in the initial management of 74 cases, whereas the remaining 12 cases were managed by primary talectomy. The mean duration of follow‐up was 32 months. Twenty‐two cases required a secondary arthrodesis or another additional procedure. A good outcome was achieved in 35% of cases, a fair outcome in 37% and a poor outcome in 27%. The complication of avascular necrosis (AVN) occurred in 22 cases and 14 subjects developed clinically significant osteoarthritis. Generally, the outcome of current treatments associated with total talar dislocation is not ideal, only 1/3 of cases achieving good outcomes. So far, preservation of the talus is the best treatment option. AVN is still a relatively common complication even in the absence of fracture or postoperative infection.
Treatment of Femoral Neck Fracture with Percutaneous Compression Plate: Preliminary Results in 74 Patients
Authors: Zhu Feng , Liu Gang , Shao Hong‐guo , Wang Yi‐jun , Li Rong‐qun , Yang Hui‐lin , Geng De‐chun , Xu Yao‐zeng
Published: June 2015

Objective

The purpose of this study was to present the surgical technique and clinical results of percutaneous compression plate (PCCP) for the treatment of femoral neck fractures.

Methods

Between December 2010 and April 2013, 74 consecutive patients with 74 femoral neck fractures were treated by closed reduction and PCCP implants in our university hospital. Their mean age was 51.3 years (range, 15–83 years); 38 (51.4%) were male and 46 (62.2%) of the fractures were on the left. The patients' clinical and radiographic data were analyzed retrospectively.

Results

There were 45 undisplaced (60.8%) and 29 displaced fractures (39.2%). Eight patients (10.8%) were lost to follow‐up. The mean duration of follow‐up was 18.8 months for the remaining 66 patients. At the last follow‐up, mean Harris hip score was 92.9 (range, 75–100), and 65 patients (98.5%) had excellent and good outcomes. Sixty‐five patients (98.5%) were able to walk independently and one (1.5%) with walking‐sticks. The mean time to clinical fracture healing was 3.9 months. There were no cases of nonunion. Two patients (3.0%) had delayed union and two (3.0%) developed avascular necrosis, one of 29 (3.7%) with a displaced fracture and one of 45 (2.6%) with an undisplaced fracture. There were no other complications or prosthetic replacement.

Conclusions

PCCP is a stable internal fixation device that resists axial and rotational stresses. Our PCCP procedure has a low incidence of nonunion and avascular necrosis.
Minimally Invasive Unicompartmental Knee Arthroplasty for Spontaneous Osteonecrosis of the Knee
Authors: Guo Wan‐shou , Zhang Qi‐dong , Liu Zhao‐hui , Cheng Li‐ming , Yue De‐bo , Wang Wei‐guo , Zhang Nian‐fei , Li Zi‐rong
Published: June 2015

Objective

To explore the outcome and surgical technique of minimally invasive unicompartmental knee arthroplasty (UKA) for spontaneous osteonecrosis of the knee.

Methods

Twenty‐seven patients with medial compartmental spontaneous osteonecrosis treated by minimally invasive Oxford phase 3 UKA from January 2009 to June 2013 were reviewed retrospectively. Twelve subjects were men and 15 women, with an average age of 64.6 ± 8.6 years (52–82 years). At the time of diagnosis, 11 patients had with grade III necrosis and 16 grade IV according to Mont's classification. Pain, range of motion (ROM) and Hospital for Special Surgery (HSS) knee scores were evaluated before and after UKA. Pre‐and postoperative alignment of the lower limbs was measured and compared. Postoperative radiographic assessments were made according to the guidelines proposed by the Oxford group at the final follow‐up.

Results

All patients were followed for a mean time of 27.8 ± 15.9 months (6–59 months). There were no serious adverse events, such as infection, bearing dislocation, aseptic loosening, pulmonary embolism, deep venous thrombosis, cardio‐cerebral vascular incident or psychological problems. One revision was required for unrelated causes (fracture of tibia plateau) 3 years after arthroplasty. One femoral component was tilted with a postoperative radiographic angle >10°. One radiolucent line was observed in a patient with spontaneous osteonecrosis of the knee. The two patients with implant failure had no symptoms at last follow‐up. Visual analogue scale scores decreased from 6.9 ± 0.9 to 2.0 ± 1.1 (t = 19.27, P = 0.00). Pain was relieved in 96.3% of subjects (26/27). The mean post‐operative ROM and femorotibial angle were 125.7° ± 9.6° and 177.7° ± 3.1°, respectively. HSS scores increased from 61.3 ± 9.7 to 93.0 ± 4.8 (t = 14.46, P = 0.00). Of the 27 patients, 26 (96.3%) were satisfied with the outcome of this surgical procedure.

Conclusion

Minimally invasive UKA is an effective means of managing spontaneous osteonecrosis of the knee. The short‐term outcome of UKA is encouraging.
Surgical Treatment of Acetabulum Top Compression Fracture with Sea Gull Sign
Authors: Zhuang Yan , Lei Jin‐lai , Wei Xing , Lu Dai‐gang , Zhang Kun
Published: June 2015

Objective

To investigate surgical procedures and their efficacy for acetabulum top compression fractures with sea gull sign.

Methods

Data of 14 patients (five women, nine men); aged from 28 to 71 years (mean, 49.9 years) who had undergone surgery for acetabulum top compression fractures with sea gull sign and been followed up were retrospectively analyzed. The time from injury to surgery was 4−14 days (mean, 9 days). All patients underwent open reduction and bone graft and internal fixation through an ilioinguinal or ilioinguinal plus Kocher−Langenbeck approach. Quality of fracture reduction was assessed according to Matta reduction criteria and hip function according to Matta acetabular fracture criteria.

Results

Fourteen patients were followed up for 6−60 months (mean, 36 months). All achieved bone healing within 3−4 months (mean, 3.4 months); the excellent and good rate being 78.5% (11/14). The Matta acetabular fracture scores were 10−18 scores (mean, 16.4); the excellent and good rate being 71.4% (10/14). Traumatic arthritis occurred in three patients. Pain was serious in two patients and relieved by total hip joint replacement and mild in one. One patient developed asymptomatic heterotopic ossification postoperatively.

Conclusion

The appropriate delay between injury and surgery with acetabular roof compression fracture with sea gull sign is from 5 to 10 days. Through an ilioinguinal or ilioinguinal plus Kocher−Langenbeck approach, excellent reduction of the articular surface can be achieved and sufficient bone graft material obtained. The clinical efficacy is satisfactory.
Total Hip Arthroplasty with Subtrochanteric Femoral Shortening Osteotomy for High Hip Dislocation
Authors: Hua Wen‐bin , Yang Shu‐hua , Xu Wei‐hua , Ye Shu‐nan , Liu Xian‐zhe , Wang Jing , Feng Yong
Published: June 2015

Objective

To evaluate the outcomes of total hip arthroplasty (THA) with subtrochanteric femoral shortening osteotomy for high hip dislocation.

Methods

In this retrospective study, the results of 24 primary THAs with acetabular reconstruction and subtrochanteric femoral shortening osteotomy in 21 patients with high hip dislocation were evaluated. The acetabula were reconstructed with cemented or uncemented cups and bone grafting. Transverse subtrochanteric femoral shortening osteotomies were applied and the osteotomy sites treated by bone grafting and cable fixation. Assessment was by Hip Harris scores and radiographic evaluation.

Results

The mean follow‐up time was 42 months (18–108 months), three cases being lost to follow‐up 18–27 months postoperatively. The HHS improved from 47.5 ± 8.7 to 88.5 ± 3.1. The mean length of femoral segments removed was 2.5 ± 0.8 cm (range, 1.0–4.5 cm) and mean acetabular inclination 43° ± 5° (range, 31°–54°). Caudalization of the femoral head center was 3.2 ± 3.0 mm (range, −3 to 12 mm) and lateralization 4.0 ± 4.0 mm (range, −9 to 11 mm). Mean greater trochanter height relative to theoretical hip center was 5.2 ± 1.0 cm (range, 3.5–7.1 cm) preoperatively and 0.2 ± 0.6 cm (range, −0.9 to 1.2 cm) postoperatively. Intraoperative trochanteric fractures occurred in three cases and sciatic nerve palsy in one.

Conclusion

THA with subtrochanteric femoral shortening osteotomy is an effective technique for treating high hip dislocation. Its advantages include improvement in limb imbalance and decreased risk of sciatic nerve injury.
Effect of Advanced Oxidation Protein Products on Articular Cartilage and Synovium in a Rabbit Osteoarthritis Model
Authors: Yu Hui , Ye Wen‐bin , Zhong Zhao‐ming , Ding Ruo‐ting , Chen Jian‐ting
Published: June 2015

Objective

Advanced oxidation protein products (AOPPs), a marker of oxidative stress, are prevalent in many kinds of disorders. Osteoarthritis (OA), mainly resulting from the regression of cartilage, chronic inflammation of the synovium and the subchondral bone remodeling. Although the inflammatory response of AOPPs on fibroblast‐like synoviocytes (FLSs) were reported, the effect of AOPPs on cartilage and synovial in vivo remains unclear. Therefore, our study aims to investigate whether AOPPs have an effect on the articular cartilage and synovial in a rabbit model of OA.

Methods

OA model were created by anterior cruciate ligament transection and medial meniscus resection (ACLT + MMx). Forty‐eight male New Zealand rabbits were randomly divided into 3 groups: sham‐operated group, AOPPs/ACLT + MMx group, and phosphate buffered saline (PBS)/ACLT + MMx group. In sham‐operated group, the anterior cruciate ligament was just exposed without transection, and then the incision was sutured. Then intra‐articular injection of AOPPs or PBS was performed in the other two groups. Through four weeks and eight weeks of treatment, rabbits in each group were sacrificed. Both hind legs were removed. India ink staining and Safranin O and fast green staining were used to evaluate the macroscopic and microscopic cartilage morphology. The protein expression of matrix metalloproteinases (MMP)‐3, MMP‐13 in synovium was measured by Western blot.

Result

The India ink score and Mankin score of AOPPs/ACLT + MMx group were both higher than the other two groups at the two time points. Western blot have revealed that intra‐articular injection of AOPPs upregulated the protein expression of MMP‐3 and MMP‐13 in synovium.

Conclusion

AOPPs participated in the occurrence and development of OA by upregulating the protein expression of MMP‐3 and MMP‐13 in synovium.
Postoperative hypoalbuminemia following surgery related to craniosynostosis
Authors: Allison Elizabeth , Evans Russell G. , Wall Steven , Johnson David , Das Sumit
Published: June 2015

Background

An episode of postoperative phenytoin toxicity in a patient undergoing surgery related to craniosynostosis highlighted the presence of hypoalbuminemia. We believe that hypoalbuminemia contributed to the altered pharmacokinetics of phenytoin in this case.

Objectives

To establish the incidence of postoperative hypoalbuminemia in patients undergoing surgery related to craniosynostosis and to investigate the likely etiology.

Methods

Data on 114 patients undergoing surgery for craniosynostosis over a 2‐year period at Oxford Children's Hospital, between May 2011 and May 2013, were retrospectively reviewed. Twenty‐two patients were excluded due to incomplete data. This cohort represents the entire population for whom transfusion data had been formally collected at our institution. Preoperative and day 1 postoperative serum albumin levels were collected from the hospital laboratory database. Data regarding blood loss and intra‐operative fluid management were reviewed from the anesthetic database. Linear regression analysis was used to establish the relationship between percentage drop in serum albumin with: (i) milliliters per kilogram (ml·kg−1) volume of albumin‐poor fluids used intra‐operatively and (ii) percentage estimated red cell mass loss.

Results

All patients experienced a statistically significant drop in serum albumin. The mean difference in albumin was 17.1 g·l−1, 95% CI (16.1–18.0) (P < 0.001). Expressed as a percentage, the mean reduction was 37.9% (range 16–61%), SD 9.7. The decrease in albumin was associated with an increase in estimated red cell mass loss (P < 0.001) and an increased ml·kg−1 volume of albumin‐poor fluids given (P < 0.001).

Conclusion

Hemodilution due to large volume blood loss and transfusion with albumin‐poor fluids is strongly associated with postoperative hypoalbuminemia in patients undergoing surgery related to craniosynostosis. Practitioners should be aware of this risk and the implications of postoperative hypoalbuminemia in this population.
Dutch Multidisciplinary Guideline for Invasive Treatment of Pain Syndromes of the Lumbosacral Spine
Authors: Itz Coen J. , Willems Paul C. , Zeilstra Dick J. , Huygen Frank J.
Published: June 2015

Objectives

When conservative therapies such as pain medication or exercise therapy fail, invasive treatment may be indicated for patients with lumbosacral spinal pain. The Dutch Society of Anesthesiologists, in collaboration with the Dutch Orthopedic Association and the Dutch Neurosurgical Society, has taken the initiative to develop the guideline “Spinal low back pain,” which describes the evidence regarding diagnostics and invasive treatment of the most common spinal low back pain syndromes, that is, facet joint pain, sacroiliac joint pain, coccygodynia, pain originating from the intervertebral disk, and failed back surgery syndrome.

Methods

The aim of the guideline is to determine which invasive treatment intervention is preferred for each included pain syndrome when conservative treatment has failed. Diagnostic studies were evaluated using the EBRO criteria, and studies on therapies were evaluated with the Grading of Recommendations Assessment, Development and Evaluation system. For the evaluation of invasive treatment options, the guideline committee decided that the outcome measures of pain, function, and quality of life were most important.

Results

The definition, epidemiology, pathophysiological mechanism, diagnostics, and recommendations for invasive therapy for each of the spinal back pain syndromes are reported.

Discussion

The guideline committee concluded that the categorization of low back pain into merely specific or nonspecific gives insufficient insight into the low back pain problem and does not adequately reflect which therapy is effective for the underlying disorder of a pain syndrome. Based on the guideline “Spinal low back pain,” facet joint pain, pain of the sacroiliac joint, and disk pain will be part of a planned nationwide cost‐effectiveness study.
Respiratory Sinus Arrhythmia and its Association with Pain in Women with Fibromyalgia Syndrome
Authors: Zamunér Antonio R , Forti Meire , Andrade Carolina P , Avila Mariana Arias , da Silva Ester
Published: June 2015

Objectives

To assess the cardiac autonomic control at rest and during the deep breathing test (DBT) and its association with pain in women with fibromyalgia syndrome (FMS).

Methods

The study included 20 women with FMS and 20 healthy women (control group, CG). The pain was quantified by assessing the pressure pain threshold (PPT), VAS of pain, and the pain component of the SF‐36 questionnaire. The RR intervals were recorded in the supine position and during the DBT. The heart rate variability (VHR) was measured by methods in the time and frequency domain.

Results

The group with FMS had abnormal cardiac autonomic modulation at rest and during DBT, compared to CG (P < 0.05). Positive correlations were found between PPT and the E/I ratio (r = 0.70), ΔFC (r = 0.66) and power spectrum density (DEP, r = 0.56) indices of DBT, as well as between pain component of the SF‐36 and the E/I ratio (r = 0.49), ΔFC (r = 0.45) and DEP (r = 0.50) indices of DBT. Significant correlations were observed between the FIQ questionnaire and the LF/HF ratio index in the supine position and the E/I ratio (r = −0.63), ΔFC (r = −0.54), and DEP (r = −0.51) indices of DBT.

Conclusions

The results of VHR indices during the supine position and the DBT women with FMS suggest impairment of neurocardiac integrity associated with pain and the impact of FMS on the quality of life.
Longitudinal association between habitual physical activity and depressive symptoms in older people
Authors: Yoshida Yuko , Iwasa Hajime , Kumagai Shu , Suzuki Takao , Awata Shuichi , Yoshida Hideyo
Published: June 2015

Aims

Prevention of depressive symptoms is an essential issue with regard to the promotion of healthy lifestyles in older people. To date, few studies have examined the relation between fluctuations in physical activity and depression among older individuals. We thus conducted a longitudinal survey of older adults to examine the effect of long‐term fluctuating physical activity on the incidence of depressive symptoms.

Methods

A 3‐year prospective cohort study was performed in a community‐based environment. A total of 680 individuals (291 men and 389 women) aged 65 years and over at the baseline assessment participated. The 15‐item Geriatric Depression Scale was used to assess depressive symptoms, with scores of ≥6 indicative of depression. Participants were categorized into the following four groups based on change in physical activity status between 2002 and 2003: sedentary, cessation, initiation, and maintenance.

Results

The incidence of depressive symptoms was 16.9% (16.8% in men and 17.0% in women) at the 3‐year follow up (in 2006). Multiple logistic regression analyses showed that physical activity maintenance (odds ratio, 0.50; 95% confidence interval, 0.30–0.83) only reduced the incidence of depressive symptoms at the 3‐year follow up after adjusting for confounding variables.

Conclusions

Continuous physical activity may be a valuable and simple way to prevent depressive symptoms in community‐dwelling older people. Therefore, it is necessary to implement interventions that teach older adults how to integrate physical activity into their daily lives.
Evaluating along‐strike variation using thin‐bedded facies analysis, Upper Cretaceous Ferron Notom Delta, Utah
Authors: Li Zhiyang , Bhattacharya Janok , Schieber Juergen
Published: June 2015

Thin‐bedded delta‐front and prodelta facies of the Upper Cretaceous Ferron Notom Delta Complex near Hanksville in southern Utah, USA, show significant along‐strike facies variability. Primary initiation processes that form these thin beds include surge‐type turbidity currents, hyperpycnal flows and storm surges. The relative proportion of sedimentary structures generated by each of these depositional processes/events has been calculated from a series of measured sedimentological sections within a single parasequence (PS6–1) which is exposed continuously along depositional strike. For each measured section, sedimentological data including grain size, lithology, bedding thickness, sedimentary structures and ichnological suites have been documented. Parasequence 6–1 shows a strong along‐strike variation with a wave‐dominated environment in the north, passing abruptly into a fluvial‐dominated area, then to an environment with varying degrees of fluvial and wave influence southward, and back to a wave‐dominated environment further to the south‐east. The lateral facies variations integrated with palaeocurrent data indicate that parasequence 6–1 is deposited as a storm‐dominated symmetrical delta with a large river‐dominated bayhead system linked to an updip fluvial feeder valley. This article indicates that it is practical to quantify the relative importance of depositional processes and determine the along‐strike variation within an ancient delta system using thin‐bedded facies analysis. The wide range of vertical stratification and grading sequences present in these event beds also allows construction of conceptual models of deposition from turbidity currents (i.e. surge‐type turbidity currents and hyperpycnal flows) and storm surges, and shows that there are significant interactions and linkages of these often paired processes.
From Normative Influence to Social Pressure: How Relevant Others Affect Whether Bystanders Join in Cyberbullying
Authors: Bastiaensens Sara , Pabian Sara , Vandebosch Heidi , Poels Karolien , Van Cleemput Katrien , DeSmet Ann , De Bourdeaudhuij Ilse
Published: June 2015

As cyberbullying is a phenomenon that is inherently social, the normative social influence of significant others can play an important role in the behaviour of adolescents involved in cyberbullying incidents. Using data from 525 adolescent bystanders of cyberbullying, we created a path model in order to investigate whether injunctive and descriptive norms of certain reference groups can cause bystanders to experience social pressure and join in cyberbullying. The results showed that social pressure fully mediated the relationship between the injunctive norm of friends approving of cyberbullying and joining in cyberbullying as a bystander. Furthermore, both the injunctive norm of parents approving of cyberbullying and bystanders’ involvement in cyberbullying perpetration were related to joining in cyberbullying as a bystander.
Platelet‐derived extracellular vesicles in plateletpheresis concentrates as a quality control approach
Authors: Black Anne , Pienimaeki‐Roemer Annika , Kenyon Oliver , Orsó Evelyn , Schmitz Gerd
Published: June 2015

BACKGROUND

Platelet‐derived extracellular vesicles (PL‐EVs) are present in plateletpheresis concentrates (PCs) and may influence the quality of PCs. The aim of the study was to analyze PC‐derived PL‐EVs and to correlate them with standard quality control (QC) variables of PCs and with donor‐specific laboratory variables.

STUDY DESIGN AND METHODS

PL‐EVs were analyzed by standard as well as advanced high‐sensitivity flow cytometry (FCM) and nanoparticle tracking analysis. A hematology analyzer was applied to the determination of platelet (PLT) count and immature PLT fraction (IPF). Functional capacity of PLTs (CD62P in response to thrombin receptor‐activating peptide 6 activation) was measured by FCM. All in vitro measurements were carried out on Day 0 and on Day 5. Altogether, a total of 42 PC samples, 15 irradiated on Day 0, were investigated.

RESULTS

Externalization of CD62P, as an indicator of intact PLT function, significantly decreased during in vitro PLT senescence and CD62P expression inversely correlated with increased PL‐EV levels. Interestingly, in fresh PCs a significant correlation was found between PL‐EVs and different hemapheresis instruments, duration of apheresis, and IPF count in peripheral blood of the donor before apheresis. In senescent PCs, the body mass index of donors inversely correlated with the PL‐EV counts.

CONCLUSION

Loss of PLT function in PCs was associated with increased PL‐EV levels. Shedding of PL‐EVs depends on shear stress influenced by different hemapheresis settings and diverse preanalytical conditions of donors. PL‐EV analysis may stimulate new quality and apheresis strategies for more vital PLTs for transfusion.
Trade Policymaking in a Resource‐rich Landlocked Country: The WTO Review of Mongolia
Authors: Sharma Kishor , Davaakhuu Oyunbadam
Published: June 2015

The aim of this paper is to provide a comprehensive assessment of the Trade Policy Review of Mongolia (TPRM) 2014. The TPRM 2014 demonstrates that the Mongolian economy is relatively open and it has very low formal trade barriers although there remain significant behind‐the‐borders barriers, including poor governance and infrastructure. Being a landlocked country, any major cross‐border‐price differences quickly results in informal trade with neighbouring China, limiting Mongolia's ability to pursue independent commercial policy. Mongolia's growth is not broad based and largely driven by the mining boom, making its economy highly vulnerable to external shocks. While this is not unique to Mongolia, and has been seen in many natural resource‐abundant countries, experience suggests that countries with sound institutions and macroeconomic policies have overcome the so‐called resource curse.
Single‐Incision Laparoscopic Sterilization of the Cheetah (Acinonyx jubatus)
Authors: Hartman Marthinus J. , Monnet Eric , Kirberger Robert M. , Schmidt‐Küntzel Anne , Schulman Martin L. , Stander Jana A. , Stegmann George F. , Schoeman Johan P.
Published: June 2015

Objective

To describe laparoscopic ovariectomy and salpingectomy in the cheetah (Acinonyx jubatus) using single‐incision laparoscopic surgery (SILS).

Study Design

Prospective cohort.

Animals

Female cheetahs (Acinonyx jubatus) (n = 21).

Methods

Cheetahs were randomly divided to receive either ovariectomy (n = 11) or salpingectomy (n = 10). The use and complications of a SILS port was evaluated in all of cheetahs. Surgery duration and insufflation volumes of carbon dioxide (CO2) were recorded and compared across procedures.

Results

Laparoscopic ovariectomy and salpingectomy were performed without complications using a SILS port. The poorly‐developed mesosalpinx and ovarian bursa facilitated access to the uterine tube for salpingectomy in the cheetah. The median surgery duration for ovariectomy was 24 minutes (interquartile range 3) and for salpingectomy was 19.5 minutes (interquartile range 3) (P = .005). The median volume of CO2 used for ovariectomy was 11.25 L (interquartile range 3.08) and for salpingectomy was 4.90 L (interquartile range 2.52), (P = .001)

Conclusions

Laparoscopic ovariectomy and salpingectomy can be performed in the cheetah using SILS without perioperative complications. Salpingectomy is faster than ovariectomy and requires less total CO2 for insufflation.
SCF increases in utero–labeled stem cells migration and improves wound healing
Authors: Zgheib Carlos , Xu Junwang , Mallette Andrew C. , Caskey Robert C. , Zhang Liping , Hu Junyi , Liechty Kenneth W.
Published: June 2015

Diabetic skin wounds lack the ability to heal properly and constitute a major and significant complication of diabetes. Nontraumatic lower extremity amputations are the number one complication of diabetic skin wounds. The complexity of their pathophysiology requires an intervention at many levels to enhance healing and wound closure. Stem cells are a promising treatment for diabetic skin wounds as they have the ability to correct abnormal healing. Stem cell factor (SCF), a chemokine expressed in the skin, can induce stem cells migration, however the role of SCF in diabetic skin wound healing is still unknown. We hypothesize that SCF would correct the impairment and promote the healing of diabetic skin wounds. Our results show that SCF improved wound closure in diabetic mice and increased HIF‐1α and vascular endothelial growth factor (VEGF) expression levels in these wounds. SCF treatment also enhanced the migration of red fluorescent protein (RFP)‐labeled skin stem cells via in utero intra‐amniotic injection of lenti‐RFP at E8. Interestingly these RFP+ cells are present in the epidermis, stain negative for K15, and appear to be distinct from the already known hair follicle stem cells. These results demonstrate that SCF improves diabetic wound healing in part by increasing the recruitment of a unique stem cell population present in the skin.
Escherichia coli O157:H7 – Discerning Facts from Fiction: An Integrated Research and Extension Project for Multiple Audiences
Authors: Moore D. A. , Smith D. R. , Sischo W. M. , Heaton K. , Besser T. E.
Published: June 2015

The O157:H7 (EcO157) epidemiology of Shiga‐toxin‐producing Escherichia coli (STEC) in cattle is complex, and myths about pre‐harvest control are perpetuated. The objectives of this project were to identify perpetuated misinformation and inform four audiences about evidence‐based risks and pre‐harvest control of EcO157 by addressing: (i) EcO157 epidemiology and pre‐harvest control; (ii) how food safety policy is created; and (iii) how to present accurate information about EcO157. An environmental scan using a daily Internet search helped identify themes for education. A literature review of pre‐harvest control measures contributed to the development of educational materials (fact sheets, website, web presentations and conferences). Conference 1 was a webinar with 315 registrants, 10 countries including 41 US states and four Canadian provinces. Most participants felt confident in using their new knowledge, more than half felt confident enough to answer EcO157 questions from the public and many would recommend the recorded version of the webinar to colleagues. Conference 2 was live in the Washington, DC, area with most participants employed by the US government. All agreed that they better understood pre‐harvest control, how food safety policy was made, and were confident they could create an effective message about STEC pre‐harvest control. Videos were posted and received 348 Internet visitors within 2 months. Conference 3 was a webinar with a live audience and Twitter feeds, targeting people who give nutrition advice. Almost all ranked the programme good to excellent and relevant to their work. About 25% indicated that they would share: ‘grass‐fed beef is not safer than grain‐fed’, 25% would share information on effectiveness of cattle vaccines, and 14% would share information on message mapping. Across all conferences, major changes in knowledge included the following: there is no additional risk of EcO157 shedding from grain‐fed versus grass‐fed cattle, pre‐harvest vaccination is efficacious, and production systems (pasture versus confinement) do not affect EcO157 shedding rates.
Mitochondrial function at extreme high altitude
Authors: Murray Andrew J. , Horscroft James A.
Published: June 2015

At high altitude, barometric pressure falls and with it inspired , potentially compromising O2 delivery to the tissues. With sufficient acclimatisation, the erythropoietic response increases red cell mass such that arterial O2 content () is restored; however arterial remains low, and the diffusion of O2 from capillary to mitochondrion is impaired. Mitochondrial respiration and aerobic capacity are thus limited, whilst reactive oxygen species (ROS) production increases. Restoration of with supplementary O2 does not fully restore aerobic capacity in acclimatised individuals, possibly indicating a peripheral impairment. With prolonged exposure to extreme high altitude (>5500 m), muscle mitochondrial volume density falls, with a particular loss of the subsarcolemmal population. It is not clear whether this represents acclimatisation or deterioration, but it does appear to be regulated, with levels of the mitochondrial biogenesis factor PGC‐1α falling, and shows similarities to adapted Tibetan highlanders. Qualitative changes in mitochondrial function also occur, and do so at more moderate high altitudes with shorter periods of exposure. Electron transport chain complexes are downregulated, possibly mitigating the increase in ROS production. Fatty acid oxidation capacity is decreased and there may be improvements in biochemical coupling at the mitochondrial inner membrane that enhance O2 efficiency. Creatine kinase expression falls, possibly impairing high‐energy phosphate transfer from the mitochondria to myofibrils. In climbers returning from the summit of Everest, cardiac energetic reserve (phosphocreatine/ATP) falls, but skeletal muscle energetics are well preserved, possibly supporting the notion that mitochondrial remodelling is a core feature of acclimatisation to extreme high altitude.
Laser-Induced Plasma Micromachining Process: Principles and Performance
Authors: Pallav Kumar , Saxena Ishan , Ehmann K. F.
Published: June 2015

Laser-induced plasma micromachining (LIP-MM) is a novel multimaterial and tool-less micromachining process. It utilizes tightly focused ultrashort laser irradiation to generate plasma through laser-induced dielectric breakdown in a dielectric material. The plasma facilitates material removal through plasma–matter interaction spot through vaporization and ablation. The paper introduces the LIP-MM process, discusses the underlying principles behind plasma generation and machining, and proves its feasibility by describing the experimental conditions under which plasma generation and machining occur. Upon successful commercial realization of this novel process, the key benefits envisaged are micromachining with better accuracy and better surface integrity, minimal subsurface damage, relatively smaller heat-affected zone (HAZ) and low roughness in a wide range of materials including those that are difficult to machine by some of the most successful micromachining processes such as micro-electrodischarge machining (EDM) and laser ablation.
A Thermohydrodynamic Coupling Model of Oil Aeration Turbulent Lubrication for Journal Bearing With Interface Effect
Authors: Lin Xiaohui , Jiang Shuyun , Hua Chengyu , Cheng Feng
Published: June 2015

Oil aeration lubricant in high-speed journal bearing is composed of mixture of continuous phase liquid and discrete phase bubbles. This work establishes a thermohydrodynamic (THD) coupling model for this lubrication condition. The generalized Reynolds equation is derived by the continuity equation, Navier–Stokes equation, law of wall turbulence model, and bubble volume distribution function, and then a THD oil aeration turbulent lubrication model is established by coupling the generalized Reynolds equation, energy equation, force equilibrium equation of bubble, and population balance equations (PBEs). The coupled-equations are solved numerically to obtain the pressure distribution under oil aeration lubrication state, the equilibrium distribution of bubble volume, the turbulent velocity distribution, the bubble velocity distribution, and the temperature rise. The results show that the load capacity of a bearing with oil aeration lubrication model is higher than that of the same bearing with a pure oil lubrication model, and heat dissipation performance of the bearing under the oil aeration lubrication state is superior.
Lagrangian Explicit Finite Element Modeling for Spin-Rolling Contact
Authors: Deng Xiangyun , Qian Zhiwei , Dollevoet Rolf
Published: June 2015

Spin in frictional rolling contact can cause significant stress, which is the key to understanding and predicting the wear and fatigue behavior of contact components, such as wheels, rails, and rolling bearings. The lateral creep force arising from spin influences the kinematics of a wheelset and thus of vehicles. The solution that is currently employed in the field of elasticity and continuum statics was developed by Kalker and uses a boundary element method (BEM). In this paper, a new approach based on Lagrangian explicit finite element (FE) analysis is employed. This approach is able to consider arbitrary geometric profiles of rails and wheels, complex material behavior and dynamic effects, and some other factors. The new approach is demonstrated using a three-dimensional (3D) model of a wheel with a coned profile rolling along a quarter cylinder and can be easily adapted to apply to wheels and rails of arbitrary profiles. The 3D FE model is configured with elastic material properties and is used to obtain both normal and tangential solutions. The results are compared with those of the Hertz theory and the Kalker's model. The 3D FE model is then configured with elastoplastic material properties to study the spin-rolling contact with plasticity. The continuum dynamics phenomenon is captured by the FE model, which enhances the ability of the model to mimic reality. This improvement considerably extends the applicability of the FE model. The model can be applied to fatigue and wear analyses at gauge corners or rails as well as to deep groove bearings, where a large geometrical spin is present and plastic deformation may be of importance.
Wear Mechanisms of Gray Cast Iron in the Presence of Environmentally Friendly Hydrofluoroolefin-Based Refrigerant and the Effect of Tribofilm Formation
Authors: Wasim Akram M. , Polycarpou Andreas A.
Published: June 2015

Hydrofluoroolefin-based refrigerant (2,3,3,3-tetrafluoropropene, namely, HFO-1234yf), which has been developed as an environmentally friendly refrigerant, is proposed as a direct replacement solution in automotive air-conditioning compressor applications. In the present work, the wear mechanisms of this refrigerant using gray cast iron interfaces were investigated under a wide range of operating conditions. A critical velocity was measured from scuffing type experiments, where beyond that maximum interfacial loads did not change significantly with sliding velocity, suggesting a mechanical rubbing-type wear mechanism. Below the critical velocity, scuffing loads decreased almost linearly with sliding velocities. Wear type experiments identified two different wear mechanisms, namely, oxygen-dominating and fluorine-dominating wear, depending on sliding velocities and normal loads. Oxygen-dominating wear mechanism prevailed under low sliding velocities and normal loads. In contrast, fluorine-dominating wear was predominant under moderate sliding velocities and low or moderate loads. The formation of protective tribofilms and their effect on the wear mechanism was used to construct a wear map.
Analysis of the Static Characteristics of a Self-Compensation Hydrostatic Spherical Hinge
Authors: Xu Chundong , Jiang Shuyun
Published: June 2015

This technical brief presents a new self-compensation hydrostatic spherical hinge to provide a large load capacity. The hinge consists of an upper part with self-compensation and a lower part with orifice restrictors. A comparative study of the static behavior is conducted between the self-compensation hydrostatic spherical hinge and the hydrostatic spherical hinge with orifice restrictors, the result shows that the self-compensation hydrostatic spherical hinge has an advantage in the static behavior over the hydrostatic spherical hinge with orifice restrictors, including a much larger load capacity, a smaller flow rate, and a smaller power loss.
Analytical Solution of Biot's Equations Based on Potential Functions Method
Authors: Hasani Baferani Abolfazl , Ohadi Abdolreza
Published: June 2015

In this paper, a new analytical solution for Biot's equations is presented based on potential functions method. The primary coupled Biot's equations have been considered based on fluid and solid displacements in three-dimensional (3D) space. By defining some potential functions, the governing equations have been improved to a simpler form. Then the coupled Biot's equations have been replaced with four-decoupled equations, by doing some mathematical manipulations. For a case study, it is assumed that the incident wave is in xy-plane and for specific boundary conditions; the partial differential equations are converted to ordinary differential equations and solved analytically. Then two foams with different properties have been considered, and acoustical properties of these foams due to the new developed method have been compared with the corresponding results presented by transfer-matrix method. Good agreement between results verifies the new presented solution. Based on the potential function method, not only the acoustical properties of porous materials are calculated, but also the analytical values of all basic field variables, such as pressure, fluid, and solid displacements, are obtained for all points in the porous media. Furthermore, fundamental features, such as damped and undamped natural frequencies, and damping coefficient of porous materials are calculated by considering presented results. The obtained results show that maximum values of field variables, such as pressure, fluid, and solid displacements, happen at the damped natural frequencies of the porous media, as expected. By increasing material thickness, the effect of damping of porous material on damped natural frequency decreases. Damping decreases the first natural frequency of the foam up to 8.5%.
Analytical Prediction of Transmission Loss in Distorted Circular Chamber Mufflers With Extended Inlet/Outlet Ports by Using a Regular Perturbation Method
Authors: Banerjee Subhabrata , Jacobi Anthony M.
Published: June 2015

The sound attenuation performance in elliptic chamber mufflers with extended inlet and outlet ports is investigated in the present work. Unlike cylindrical geometries, the ellipticity of the chamber prevents development of analytical solutions in terms of the elliptic eigenfunctions. In order to overcome this geometric limitation, a perturbation-based approach is adopted through this work. For moderate chamber eccentricities, transmission loss (TL) curves derived through the perturbed eigensolutions are observed to compare well with numerical simulations. The effects of higher-order propagating modes on the TL curves, which otherwise are nonpropagating for the corresponding cylindrical chamber extended muffler are discussed. Parametric studies on different tuned duct extensions are presented to show broadband sound attenuation.
Seven-Parameter Linear Viscoelastic Model Applied to Acoustical Damping Materials
Authors: Gourdon E. , Sauzéat C. , Di Benedetto H. , Bilodeau K.
Published: June 2015

In this paper, linear viscoelastic rheological properties of acoustical damping materials are predicted. A rheological model, based on a mechanical element approach, is presented. It consists of a combination of two springs, two parabolic elements, and one dashpot (2S2P1D). This model is applied to different acoustical damping materials. Its specificity comes from the fact that elements might be linked to structural and physical features. Parameters might be experimentally determined by tests. Application of the 2S2P1D linear viscoelastic model can adequately predict the behavior of acoustical damping materials with good accuracy. If the material verifies the time–temperature superposition principle (TTSP), the proposed model can predict the behavior on a wide frequency range, even with a small number of available data.
Simultaneous Optimization of Damping and Tracking Controller Parameters Via Selective Pole Placement for Enhanced Positioning Bandwidth of Nanopositioners
Authors: Russell Douglas , Fleming Andrew J. , Aphale Sumeet S.
Published: June 2015

Positive velocity and position feedback (PVPF) is a widely used control scheme in lightly damped resonant systems with collocated sensor actuator pairs. The popularity of PVPF is due to the ability to achieve a chosen damping ratio by repositioning the poles of the system. The addition of a tracking controller, to reduce the effects of inherent nonlinearities, causes the poles to deviate from the intended location and can be a detriment to the damping achieved. By designing the PVPF and tracking controllers simultaneously, the optimal damping and tracking can be achieved. Simulations show full damping of the first resonance mode and significantly higher bandwidth than that achieved using the traditional PVPF design method, allowing for high-speed scanning with accurate tracking. Experimental results are also provided to verify performance in implementation.
Subtle Differences During Posturography Testing Can Influence Postural Sway Results: The Effects of Talking, Time Before Data Acquisition, and Visual Fixation
Authors: Taylor Melissa R. , Sutton Erin E. , Diestelkamp Wiebke S. , Bigelow Kimberly Edginton
Published: June 2015

The goal of this study was to examine the effects of 3 factors and their interactions on posturography: a period of time to become accustomed to the force platform before the initiation of data collection, presence of a visual fixation point, and participant talking during testing. The postural stability of 30 young adults and 30 older adults was evaluated to determine whether any observed effects were confounded with age. Analysis of variance techniques were used to test all possible combinations of the 3 factors. We hypothesized that all 3 factors would significantly affect postural stability. For both participant groups, the results suggest that a period of time to become accustomed to the force platform before the initiation of data collection and a visual fixation point significantly affect postural control measures, while brief participant talking does not. Despite this, no significant interactions existed suggesting that the effects of these factors, which may occur in clinical testing, do not depend on each other. Our results suggest that inconsistencies in posturography testing methods have the potential to significantly affect the results of posturography, underscoring the importance of developing a standardized testing methodology.