bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction and experimental validation of a simple, compact, resealable, and reliable Vycor® superleak assembly for use at low temperatures
Authors: Jahromi Amir E. , Miller Franklin K.
Published: April 2016

A new method of constructing a superleak assembly for use in experiments involving 4He or 3He-4He mixtures at very low temperatures is described. Superleaks are made of a porous medium with very small pores and channels. Superleaks are often incorporated in thermomechanical pumps, superfluid magnetic pumps, dilution refrigerators, and superfluid helium transfer systems. We used several cylindrical pieces of Vycor, a permeable glass with average pore diameter of 40 Å and porosity of 28%, as a candidate to be used in our superleak assembly. Our design is simple and compact. Our superleak assembly can be disassembled and easily reassembled for reuse. We successfully tested and validated this device at temperatures between 1.4 K and 2.7 K. We experienced no superfluid leaks into the surrounding vacuum. We also report that thermal cycling caused no performance degradation. It is our goal to share the design and construction techniques of this new superleak assembly.
Coexistence of negative photoconductivity and hysteresis in semiconducting graphene
Authors: Zhuang Shendong , Chen Yan , Xia Yidong , Tang Nujiang , Xu Xiaoyong , Hu Jingguo , Chen Zhuo
Published: April 2016

Solution-processed graphene quantum dots (GQDs) possess a moderate bandgap, which make them a promising candidate for optoelectronics devices. However, negative photoconductivity (NPC) and hysteresis that happen in the photoelectric conversion process could be harmful to performance of the GQDs-based devices. So far, their origins and relations have remained elusive. Here, we investigate experimentally the origins of the NPC and hysteresis in GQDs. By comparing the hysteresis and photoconductance of GQDs under different relative humidity conditions, we are able to demonstrate that NPC and hysteresis coexist in GQDs and both are attributed to the carrier trapping effect of surface adsorbed moisture. We also demonstrate that GQDs could exhibit positive photoconductivity with three-order-of-magnitude reduction of hysteresis after a drying process and a subsequent encapsulation. Considering the pervasive moisture adsorption, our results may pave the way for a commercialization of semiconducting graphene-based and diverse solution-based optoelectronic devices.
Noise in waveguide between 18 GHz and 26.5 GHz
Authors: ALLAL D
Published: April 2016

This report summarises the results of the Key Comparison CCEM.RF-K22.W on noise temperature, performed between October 2007 and February 2011. In this comparison, the available noise temperature of three noise sources was determined by six National Metrology Institutes (NMIs) in the frequency range from 18 GHz to 26.5 GHz.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Gravitational waves from the remnants of the first stars
Authors: Hartwig Tilman , Volonteri Marta , Bromm Volker , Klessen Ralf S. , Barausse Enrico , Magg Mattis , Stacy Athena
Published: April 2016

Gravitational waves (GWs) provide a revolutionary tool to investigate yet unobserved astrophysical objects. Especially the first stars, which are believed to be more massive than present-day stars, might be indirectly observable via the merger of their compact remnants. We develop a self-consistent, cosmologically representative, semi-analytical model to simulate the formation of the first stars. By extrapolating binary stellar-evolution models at 10 per cent solar metallicity to metal-free stars, we track the individual systems until the coalescence of the compact remnants. We estimate the contribution of primordial stars to the merger rate density and to the detection rate of the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO). Owing to their higher masses, the remnants of primordial stars produce strong GW signals, even if their contribution in number is relatively small. We find a probability of ≳1 per cent that the current detection GW150914 is of primordial origin. We estimate that aLIGO will detect roughly 1 primordial BH–BH merger per year for the final design sensitivity, although this rate depends sensitively on the primordial initial mass function (IMF). Turning this around, the detection of black hole mergers with a total binary mass of ∼ 300 M⊙ would enable us to constrain the primordial IMF.
Posterolaterally displaced and flexion-type supracondylar fractures are associated with a higher risk of open reduction
Authors: Novais Eduardo N. , Carry Patrick M. , Mark Bryan J. , De Sayan , Miller Nancy H.
Published: April 2016

To identify factors predictive of the risk of conversion from closed to open reduction. International Classification of Disease-9 codes were used to identify completely displaced pediatric supracondylar humerus fractures that were subjected to planned closed reduction and percutaneous pinning. Clinical and radiographic variables were retrospectively collected. Compared with posterior extension fractures, flexion (risk ratio: 34.1, 95% confidence interval: 8.1–143.6, P<0.0001) and posterolateral extension (risk ratio: 6.0, 95% confidence interval: 1.3–27.5, P=0.0221) fractures were significantly more likely to undergo conversion from closed to open reduction. The direction of displacement should be considered during the preoperative evaluation of supracondylar fractures.
Vitamin-D measurement in patients with adolescent idiopathic scoliosis
Authors: Balioglu Mehmet B. , Aydin Canan , Kargin Deniz , Albayrak Akif , Atici Yunus , Tas Suleyman K. , Kaygusuz Mehmet A.
Published: April 2016

Our retrospective study compared vitamin-D levels in 229 patients with adolescent idiopathic scoliosis (AIS) and 389 age-matched controls, and evaluated the correlation between vitamin-D levels and sex, Cobb’s angle, and serum levels of calcium (Ca), phosphorus, and alkaline phosphatase in the AIS group. Vitamin-D levels were lower in the AIS group, with no sex-specific effects, indicative of a possible vitamin-D resistance in AIS. Vitamin-D levels correlated positively with Ca levels and negatively with Cobb’s angle, indicative of a possible role of vitamin D in the etiopathogenesis of AIS. Patients with AIS should be monitored for vitamin-D deficiency/insufficiency.
MRI Phenotyping of COL9A2/Trp2 and COL9A3/Trp3 Alleles in Lumbar Disc Disease
Authors: Bagheri Mohammad H. , Honarpisheh Amir P. , Yavarian Majid , Alavi Zahra , Siegelman Jenifer , Valtchinov Vladimir I.
Published: April 2016

Study Design.

A case-control study of the Trp2/3 alleles of COL9A2/3 genes and their correlation with occurrence of Lumbar disc disease (DDD) as phenotyped by magnetic resonance imaging.

Objective.

To establish a better understanding of relationship between presence of said alleles and occurrence of DDD in South-Western Iranian population.

Summary of Background Data.

A number of genetic predisposing factors have been identified in elevating the risk of developing DDD. Specifically, the Trp2 and Trp3 alleles of COL9A2 and COL9A3 genes have been suggested as DDD risk variants.

Methods.

A total of 108 patients (mean age = 41±11.8 yrs, range = 20–66 yrs) with 57 controls (mean age = 35±10.0 yrs, range = 20–58 yrs) participated in the study. The frequency of G/A polymorphism in COL9A2 gene on location 326 on chromosome 1 and G/A/C/ or T polymorphism in 103 location of COL9A3 gene on chromosome 20 was assessed using a PCR short-primer technique. Outcome measure was defined as presence of DDD on MRI. Odds ratios (OR) and 95% confidence intervals (CI) were used to assess the likelihood of DDD given occurrence of Trp2(3).

Results.

Each allele was present in both patients and controls. The Trp2 allele was positive in 28.5% of individuals (31.5% of patients; 22.8% of controls), OR 1.55 (0.71–3.56). The Trp3 allele, the frequency was 23.6% in all patients (26.9% patients; 17.5% controls), OR 1.72 (0.73–4.33). We observed a 5.8-fold increase in the odds of DDD in males when the Trp3 allele was present, OR 5.83 (1.09–9.98), P = 0.0273.

Conclusion.

Both Trp2 and Trp3 alleles occurred more frequently compared with other studied ethnicities. The sampled Iranian population exhibited a similar Trp2 frequency to a Southern Chinese population, and Trp3 occurrence to Finnish and Greek population. We found that male patient were much more likely to develop DDD when Trp 3 was present.

Level of Evidence: N/A
Diagnosis and Treatment of C4 Radiculopathy
Authors: Ross Donald A. , Ross Miner N.
Published: April 2016

Study Design.

Clinical case series.

Objective.

This study sought to clarify symptoms, diagnostic criteria, and treatment of C4 radiculopathy, and the role of diagnostic C4 root block in this entity.

Summary of Background Data.

Although well understood cervical dermatomal/myotomal syndromes have been described for symptoms originating from impingement on the C2, C3, C5, C6, C7, and C8 roots, less has been written about the syndrome(s) associated with the C4 root.

Methods.

The senior author reviewed surgical records and describes his personal experience with the diagnosis and treatment of C4 radiculopathy.

Results.

A total of 712 procedures for cervical radiculopathy without myelopathy were reviewed. Among that cohort, 13 procedures involved the C4 root only and five procedures involved two level procedures including the C4 root. Patients described pain as involving the axial cervical region, paraspinal muscles, trapezius muscle, and interscapular region. No patient described pain over the anterior chest wall or radiating distal to the shoulder, one described pain over the medial clavicle. All patients who were offered surgery had a positive response to a diagnostic C4 transforaminal single nerve root block. Thirteen patients underwent posterior foraminotomy (five at two levels) and five patients underwent an anterior discectomy and fusion at C3-4. Mean Oswestry Disability Index score significantly declined; preoperative score 24.3 (range 14–29), postoperative score 9.7 (range 2–18; P = 0.003) at ≥3 months. Mean Short Form-36v2 score significantly increased; preoperative score 34.2 (range 20–40.2), postoperative score 73.7 (range 40.5–88.3, P = 0.001) at ≥3 months.

Conclusion.

C4 root symptoms overlap those of the C3 and C5 roots and are very similar to facet mediated pain. Asymptomatic C4 foraminal stenosis may be a common imaging finding, it can be difficult to diagnose C4 radiculopathy clinically. Diagnostic C4 root block can make an accurate diagnosis and lead to successful surgical outcomes.

Level of Evidence: 4
Are Traditional Radiographic Methods Accurate Predictors of Pedicle Morphology?
Authors: Simpson Venita , Clair Brandon , Ordway Nathaniel R. , Albanese Stephen A. , Lavelle William F.
Published: April 2016

Study Design.

Cadaveric in vitro computed tomography (CT) imaging study.

Objective.

To examine minimum pedicle diameter from transverse and coronal CT reconstructions of thoracolumbar spine specimens and compare their degree of disparity, if any. Pedicle angulation in coronal and transverse planes was measured and their contribution to the disparity in minimum pedicle diameter was assessed.

Summary of Background Data.

Spinal minimum pedicle diameter can be obtained from both transverse and coronal CT reconstructions; however, the degree of disparity in these measurements has not been described previously. Angulation of the pedicle in transverse and coronal planes may contribute to a disparity in minimum pedicle diameter acquired from reconstructions. This also has not been described previously. This study examined whether the disparity could be predicted by spinal level, as pedicle angulations vary in both coronal and transverse planes.

Methods.

Five thoracolumbar specimens (T1-L5, age 48–59 yrs, male) were CT scanned utilizing clinical protocols. Minimum pedicle diameters and pedicle angulations were acquired in transverse and coronal reconstructions. Disparities between minimum pedicle diameters were measured and the correlation between this disparity and spinal level was characterized.

Results.

A significant difference (P < 0.001) in minimum pedicle diameter existed between measures from coronal and transverse reconstructions. There was a significant correlation (P < 0.001) between the difference in minimal pedicle diameter and the transverse pedicle angle as well as the coronal pedicle angle.

Conclusion.

An overestimation of minimum pedicle diameter in the transverse reconstruction occurs when the coronal pedicle angulation increases, and in the coronal reconstruction when the transverse pedicle angulation increases. Therefore, pedicle angle should be determined using both coronal and transverse reconstructions and utilized to reduce the risk of overestimation of the true pedicle diameter.

Level of Evidence: NA
Longitudinal Study of the Six Degrees of Freedom Cervical Spine Range of Motion During Dynamic Flexion, Extension, and Rotation After Single-level Anterior Arthrodesis
Authors: Anderst William J. , West Tyler , Donaldson William F. , Lee Joon Y. , Kang James D.
Published: April 2016

Study Design.

A longitudinal study using biplane radiography to measure in vivo intervertebral range of motion (ROM) during dynamic flexion/extension, and rotation.

Objective.

To longitudinally compare intervertebral maximal ROM and midrange motion in asymptomatic control subjects and single-level arthrodesis patients.

Summary of Background Data.

In vitro studies consistently report that adjacent segment maximal ROM increases superior and inferior to cervical arthrodesis. Previous in vivo results have been conflicting, indicating that maximal ROM may or may not increase superior and/or inferior to the arthrodesis. There are no previous reports of midrange motion in arthrodesis patients and similar-aged controls.

Methods.

Eight single-level (C5/C6) anterior arthrodesis patients (tested 7 ± 1 months and 28 ± 6 months postsurgery) and six asymptomatic control subjects (tested twice, 58 ± 6 months apart) performed dynamic full ROM flexion/extension and axial rotation whereas biplane radiographs were collected at 30 images per second. A previously validated tracking process determined three-dimensional vertebral position from each pair of radiographs with submillimeter accuracy. The intervertebral maximal ROM and midrange motion in flexion/extension, rotation, lateral bending, and anterior-posterior translation were compared between test dates and between groups.

Results.

Adjacent segment maximal ROM did not increase over time during flexion/extension, or rotation movements. Adjacent segment maximal rotational ROM was not significantly greater in arthrodesis patients than in corresponding motion segments of similar-aged controls. C4/C5 adjacent segment rotation during the midrange of head motion and maximal anterior-posterior translation were significantly greater in arthrodesis patients than in the corresponding motion segment in controls on the second test date.

Conclusion.

C5/C6 arthrodesis appears to significantly affect midrange, but not end-range, adjacent segment motions. The effects of arthrodesis on adjacent segment motion may be best evaluated by longitudinal studies that compare maximal and midrange adjacent segment motion to corresponding motion segments of similar-aged controls to determine if the adjacent segment motion is truly excessive.

Level of Evidence: 3
Influence of Sacral Slope on the Loading of Pedicle Screws in Postoperative L5/S1 Isthmic Spondylolisthesis Patient
Authors: Chen Liang , Feng Yu , Che Chun-Qing , Gu Yong , Wang Ling-Jun , Yang Hui-Lin
Published: April 2016

Study Design.

A finite element analysis.

Objective.

To evaluate the influence of sacral slope (SS) on the loading of pedicle screws in postoperative isthmic spondylolisthesis (IS).

Summary of Background Data.

The spinopelvic anatomy was important for the biomechanics in spondylolisthesis. To our knowledge, no study concentrated on the postoperative biomechanics of the IS with the different SS.

Methods.

Based on the computed tomography images, a finite model of L5/S1 IS was constructed. Posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) models were simulated with different sacral slope (35°, 40°, 45°, 50°, and 55°). Moreover, 500N preload was imposed on the L5 superior endplate and 15 Nm was given to simulate flexion, extension, lateral flexion, and rotation of the body. The maximum stress on the instrumentation was recorded in different model with different sacral slope.

Result.

The model of the L5/S1 IS was verified to be valid. The maximum stress on the internal fixation system of each model was always at the posterior part of the sacral screw or connection point between screw and rod. Except for the SS of 35° in PLIF model, all the maximum stress occurred in flexion loading, which was 535.47 MPa for PLF and 339.49 MPa for PLIF with SS of 55°. The stress on the sacral screw of the PLF was higher than that of the PLIF model with same sacral slope, for example, 453.38 MPa for PLF, 282.64 MPa for PLIF under flexion with SS of 45°. With the increase of the SS, the maximum stress on the sacral screws increased in both the PLF and PLIF models.

Conclusion.

The maximum stress on the internal fixation system of the PLF and PLIF concentrated at the posterior part of sacral screw or the connection point between the screw and rod. With the same SS, the stress on the screw of PLF was higher than that of PLIF. PLIF may be a better choice for IS with a high SS.

Level of Evidence: N/A
Investigating associations of cyclooxygenase-2 expression with angiogenesis, proliferation, macrophage and T-lymphocyte infiltration in canine melanocytic tumours
Authors: Gregório Hugo , Raposo Teresa P. , Queiroga Felisbina L. , Prada Justina , Pires Isabel
Published: April 2016

Cyclooxygenase-2 (COX-2) is known to be involved in tumour progression and has been suggested as a therapeutic target in many human and animal malignancies. A number of different pathways subjacent to cancer hallmarks are considered to be involved in COX-2-mediated tumour progression, although these are still largely undefined. Our aim is to investigate associations between COX-2 expression and angiogenesis, proliferation and the inflammatory microenvironment in canine melanocytic tumours. Understanding the involvement of COX-2 with cancer hallmarks might enable us to adapt therapeutic strategies for canine melanomas, an aggressive and often lethal malignancy with value in comparative oncology. Immunohistochemical staining of COX-2, Ki-67 (proliferation index), vascular endothelial growth factor (VEGF), factor VIII (microvessel density), CD3 (lymphocytes) and MAC387 (macrophages) was performed in 51 melanocytic tumours (31 malignant melanomas, 20 melanocytomas). Statistical associations between COX-2 and the other parameters detected were analysed. In melanocytic tumours (n=51), both COX-2 labelling extension and intensity showed a statistically significant association with angiogenesis by factor VIII, VEGF, Ki-67, CD3+ T lymphocytes and MAC387. Within malignant melanomas, COX-2 expression has shown significant associations with microvessel density (factor VIII), lymphocyte and macrophage infiltration and, considering all melanocytic tumours, COX-2 was also associated with VEGF intensity and Ki-67 cell proliferation. Our results point to a role for COX-2 in angiogenesis and in the establishment of an inflammatory microenvironment, favourable to melanoma tumour progression. Further mechanistic studies are warranted to dissect molecular pathways in which COX-2 is involved. Present evidence suggests that COX-2 inhibitors might be useful as an adjuvant treatment to hinder canine melanoma progression.
A 15-year-old Girl with an Asymmetric Hemitruncal Fat Distribution: Hemihyperthrophy or Hemiatrophy?
Authors: van der Velpen Inge , Schendelaar Pamela , van Pinxteren-Nagler Evelyn , Mouës-Vink Chantal M.
Published: April 2016

A 15-year-old girl presented to the pediatrician with complaints of excessive fat distribution on the right side and breast asymmetry. At age 2, she had undergone a left-sided nephrectomy because of a stage III Wilms tumor using a transverse cut supraumbilical approach, followed by systemic chemotherapy and local radiotherapy. In the case of trunk asymmetry, it is questionable which side is deviant. The asymmetry may be an expression of isolated hemihyperthrophy, syndromal hemihypertrophy related to the Wilms tumor, or an expression of left-sided hemiatrophy as a late consequence of radiotherapy, chemotherapy, or surgery. Late clinical manifestations of childhood cancer treatment are difficult to distinguish from other independent diseases but must be considered as explanations for new onset of symptoms in adolescents.
Blepharoplasty with a Buried Double Twisted Suture Technique to Correct Upper Eyelid Epiblepharon
Authors: Choi Seung Woo , Goldberg Robert A. , Lew Helen
Published: April 2016

Background:

The authors evaluated the clinical efficacy of blepharoplasty using a newly developed, buried double twisted suture (BDTS) technique to correct upper eyelid epiblepharon.

Methods:

This retrospective study was conducted from October 2013 to July 2015 at the Oculoplastic Clinic, Bundang CHA Medical Center, CHA University, Seongnam, Korea. A total of 122 eyes from 61 patients with upper eyelid epiblepharon were enrolled. Blepharoplasty with a BDTS technique was performed on all eyes, followed by evaluation of clinical outcomes and complications. After surgery, success was defined as the persistence of a double eyelid and the upper eyelid eyelashes not touching the cornea under slit lamp examination.

Results:

The 61 patients were composed of 29 females and 32 males. The average age was 9.0 ± 7.7 years, and the average follow-up period was 7.3 ± 5.2 months. After surgery, the margin reflex distance increased from 2.0 ± 1.0 to 3.2 ± 0.9 mm (P < 0.05). The success rate was 98.1%. Epiblepharon recurred in 1 patient (1.9%) and was treated after 2 months. Knot exposure was a postoperative complication in 2 patients (3.8%). The knots were buried in the deep layer under local anesthesia. Overall, all cases showed good results without complications.

Conclusions:

Blepharoplasty with a BDTS technique is relatively simple and effective for correction of epiblepharon with a low rate of complications. This technique can be applied to double eyelid surgery based on the excellent cosmetic outcomes.
Impact of Physical Inactivity on Risk of Developing Cancer of the Uterine Cervix: A Case-Control Study
Authors: Szender James Brian , Cannioto Rikki , Gulati Nicolas R. , Schmitt Kristina L. , Friel Grace , Minlikeeva Albina , Platek Alexis , Gower Emily H. , Nagy Ryan , Khachatryan Edgar , Mayor Paul C. , Kasza Karin A. , Lele Shashikant B. , Odunsi Kunle , Moysich Kirsten B.
Published: April 2016

Objective

In this study, we investigated whether physical inactivity was associated with risk of cervical cancer in women treated at an American cancer hospital.

Methods

This case-control study included 128 patients with cervical cancer and 512 controls matched on age. Controls were women suspected of having but not ultimately diagnosed with a neoplasm. Physical inactivity was defined in accordance with the 2008 Physical Activity Guidelines for Americans. Thus, participants reporting, on average, no moderate or vigorous recreational physical activity were classified as inactive. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Compared with noncancer controls, those with cervical cancer had significantly increased odds of reporting abstinence from recreational physical activity (OR, 2.43; 95% CI, 1.56–3.80). No association was noted between occupational-related physical inactivity and cervical cancer (OR, 0.88; 95% CI, 0.58–1.36).

Conclusions

Our findings suggest that abstinence from regular recreational physical activity is associated with increased odds of cervical cancer. To our knowledge, this is the first US-based study examining these associations. Given the 2008 Physical Activity Guidelines for Americans, this study has identified yet another potential public health benefit to regular physical activity. Further investigation is needed using a larger sample and prospectively collected data to characterize dose of activity to mitigate risk and the optimal window of susceptibility.
Long‐Term Follow‐Up of Children Treated With Peginterferon and Ribavirin for Hepatitis C Virus Infection
Authors: Haber Barbara , Alonso Estella , Pedreira Alejandra , Rodriguez‐Baez Norberto , Ciocca Mirta , Lacaille Florence , Lang Thomas , Gonzalez Teresita , Goodman Zachary , Yang Zijiang , Jackson Beth , Noviello Stephanie , Albrecht Janice K.
Published: April 2016

Objectives:

The aim of the study was to describe the 5‐year follow‐up of children who received peginterferon and ribavirin in a global, open‐label study.

Methods:

A 5‐year follow‐up study of 107 children and adolescents ages 3 to 17 years with chronic hepatitis C virus infection who received peginterferon and ribavirin for 24 or 48 weeks. No drugs were administered during follow‐up.

Results:

Ninety‐four patients were enrolled in the long‐term follow‐up portion of the study; the median duration of follow‐up was 287 weeks (range, 73–339). Of 63 patients with sustained virologic response who were enrolled, 54 completed 5 years of follow‐up; none had relapse in the 5‐year follow‐up period. Significant decreases in height z scores were observed during treatment. The effect of treatment on height z score was larger in patients treated for 48 weeks compared with those treated for 24 weeks (mean change from baseline to the end of treatment was −0.13 [P < 0.001] and −0.44 [P < 0.001] in the 24‐ and 48‐week treatment groups, respectively). Among patients treated for 24 weeks, full recovery of height z scores to baseline was observed by 1 year of follow‐up, whereas only partial recovery was observed during 5 years of follow‐up in patients treated for 48 weeks (mean change from baseline to the final follow‐up visit was −0.16 (P = NS) and −0.32 (P < 0.05) in the 24‐ and 48‐week treatment groups, respectively). Similar patterns were observed for weight and body mass index z scores.

Conclusions:

Impairment of growth should be considered when assessing the risk‐benefit profile of peginterferon/ribavirin therapy in children with hepatitis C virus infection. In deciding to treat children with chronic hepatitis C virus, considerations should include both deferring treatment in patients during optimal growth periods, and the possibility that interferon‐free regimens may be available to children in the next 5 to 10 years.
Savary Dilation Is Safe and Effective Treatment for Esophageal Narrowing Related to Pediatric Eosinophilic Esophagitis
Authors: Al‐Hussaini Abdulrahman
Published: April 2016

Objectives:

Data on management of esophageal narrowing related to eosinophilic esophagitis (EoE) in children are scanty. The aim of the present study is to assess the safety and effectiveness of esophageal dilation in pediatric EoE from the largest case series to date.

Methods:

Children diagnosed with EoE during 2004 to 2015 were reviewed for the presence of esophageal narrowing. Esophageal narrowing was categorized as short segment narrow caliber, long segment narrow caliber, and single short stricture. The characteristics of the narrowed esophagus, therapeutic approach, clinical outcome, and complications were reviewed.

Results:

Of the 50 EoE cases diagnosed during the study period, 11 cases (9 boys; median age 9 years, range 4–12) were identified with esophageal narrowing (22%). Six had short segment narrow caliber esophagus and 5 had long segment narrow caliber esophagus (median length of the narrowing was 4 cm, range 3–20 cm). Three cases with narrow caliber esophagus also had esophageal stricture 2 to 3 cm below the upper esophageal sphincter. Nineteen dilation sessions were performed in 10 cases using Savary dilator. Esophageal size improved from median 7 mm to median 13.4 mm. Good response was obtained in all cases. Following the dilation procedure, longitudinal esophageal mucosal tear occurred in all cases without esophageal perforation or chest pain.

Conclusions:

Esophageal dilation using Savary dilator is safe and highly effective in the management of esophageal narrowing related to EoE in children. Dilation alone does not improve the inflammatory process, and hence a combination with dietary or medical intervention is required.
Sniffing Out Paediatric Gastrointestinal Diseases
Authors: Buijck Martin , Berkhout Daniel J.C. , de Groot Evelien F.J. , Benninga Marc A. , van der Schee Marc P.C. , Kneepkens Corneille Marie Frank , de Boer Nanne K.H. , de Meij Tim G.J.
Published: April 2016

The diagnostic work‐up and follow‐up of paediatric functional gastrointestinal disorders and organic conditions usually includes invasive tests, carrying a high burden on patients. There is a place, therefore, for novel, noninvasive disease‐specific biomarkers. Volatile organic compounds (VOCs), originating from (patho)physiological metabolic processes in the human body, are excreted as waste products through all conceivable bodily excrements. The spectrum of VOCs harbours a magnificent source of information, with the potential to serve as noninvasive diagnostic biomarkers and to monitor disease activity. VOC analysis has been studied in children and infants with a variety of gastrointestinal diseases, including inflammatory bowel disease, liver diseases, irritable bowel syndrome, necrotizing enterocolitis and infectious diarrhoea. Most of these studies, although limited in sample size, show that patients can be discriminated from controls based on their VOC profiles, underscoring the potential of VOC analysis in diagnosis and follow‐up. Currently, however, the application of VOC analysis in clinical practice is limited; substantial challenges, including methodological, biological, and analytical problems, still need to be met. In this review we provide an overview of the available literature on the potential of VOCs as biomarkers for paediatric gastrointestinal diseases. We discuss the available techniques to analyse VOCs and provide topics for VOC‐related research, which need to be addressed before VOC diagnostics can be implemented in daily clinical practice.
Exploratory Investigation of Early Biomarkers for Chronic Fatigue in Prostate Cancer Patients Following Radiation Therapy
Authors: Feng Li Rebekah , Wolff Brian S. , Lukkahatai Nada , Espina Alexandra , Saligan Leorey N.
Published: April 2016

Background:

Fatigue is one of the most debilitating adverse effects of cancer therapy. Identifying biomarkers early during cancer therapy may help us understand the biologic underpinnings of the persistence of fatigue following therapy.

Objective:

We aimed to identify early biomarkers of fatigue by examining correlations of levels of cytokines during external beam radiation therapy (EBRT) with persistence of fatigue 1 year following treatment completion in men with nonmetastatic prostate cancer (NM-PC).

Methods:

A sample of 34 men with nonmetastatic prostate cancer scheduled to receive EBRT were followed up at baseline (T1), midpoint of EBRT (T2), and 1 year following EBRT (T3). Demographic and clinical data were obtained by chart review. The Functional Assessment of Cancer Therapy–Fatigue was administered to measure fatigue levels. Plasma cytokine levels were determined at T1 and T2 using the Bio-Rad Bio-Plex Cytokine Assay Kits.

Results:

Significant correlations were observed between levels of interleukin 2 (IL-3), IL-8, IL-9, IL-10, IL-16, interferon γ–induced protein 10, interferon α2, interferon γ, and stromal cell–derived factor 1α at T2 with worsening of fatigue from T1 to T3.

Conclusions:

Immunological changes prior to chronic fatigue development may reflect the long-term response to radiation therapy–induced damage.

Implications for Practice:

Early biomarkers for chronic fatigue related to cancer therapy will help advance our understanding of the etiology of this distressing symptom and will help nurses identify patients at risk of developing chronic fatigue after cancer treatment. This information will also aid in patient education, as well as symptom management.
Clinical Correlates of Planned and Unplanned Suicide Attempts
Authors: Chaudhury Sadia R. , Singh Tanya , Burke Ainsley , Stanley Barbara , Mann J. John , Grunebaum Michael , Sublette M. Elizabeth , Oquendo Maria A.
Published: April 2016

Suicide attempters differ in the degree of planning for their suicide attempts. The purpose of this study was to identify differences between individuals who make planned (≥3 hours of planning) and unplanned (<3 hours of planning) suicide attempts. Depressed suicide attempters (n = 110) were compared based on degree of planning of their most recent suicide attempt on demographic and clinical variables. Participants who made planned suicide attempts were more likely to have family history of completed suicide, more severe and frequent suicidal ideation, greater trait impulsivity, and greater suicidal intent and more severe medical consequences for both their most recent and most serious suicide attempts. These results suggest clear clinical differences based on the degree of suicide attempt planning. Severe suicidal ideation, high suicide intent, family history of suicide completion, and high levels of motor impulsivity contribute to a phenotype that is at greater risk of planned, highly lethal suicide attempts.
Point of impact: the effect of size and speed on puncture mechanics
Authors: Anderson P. S. L. , LaCosse J. , Pankow M.
Published: April 2016

The use of high-speed puncture mechanics for prey capture has been documented across a wide range of organisms, including vertebrates, arthropods, molluscs and cnidarians. These examples span four phyla and seven orders of magnitude difference in size. The commonality of these puncture systems offers an opportunity to explore how organisms at different scales and with different materials, morphologies and kinematics perform the same basic function. However, there is currently no framework for combining kinematic performance with cutting mechanics in biological puncture systems. Our aim here is to establish this framework by examining the effects of size and velocity in a series of controlled ballistic puncture experiments. Arrows of identical shape but varying in mass and speed were shot into cubes of ballistic gelatine. Results from high-speed videography show that projectile velocity can alter how the target gel responds to cutting. Mixed models comparing kinematic variables and puncture patterns indicate that the kinetic energy of a projectile is a better predictor of penetration than either momentum or velocity. These results form a foundation for studying the effects of impact on biological puncture, opening the door for future work to explore the influence of morphology and material organization on high-speed cutting dynamics.
Is fracture a bigger problem for smaller animals? Force and fracture scaling for a simple model of cutting, puncture and crushing
Authors: Schofield Robert M. S. , Choi Seunghee , Coon Joshua J. , Goggans Matthew Scott , Kreisman Thomas F. , Silver Daniel M. , Nesson Michael H.
Published: April 2016

Many of the materials that are challenging for large animals to cut or puncture are also cut and punctured by much smaller organisms that are limited to much smaller forces. Small organisms can overcome their force limitations by using sharper tools, but one drawback may be an increased susceptibility to fracture. We use simple contact mechanics models to estimate how much smaller the diameter of the tips or edges of tools such as teeth, claws and cutting blades must be in smaller organisms in order for them to puncture or cut the same materials as larger organisms. In order to produce the same maximum stress when maximum force scales as the square of body length, the diameter of the tool region that is in contact with the target material must scale isometrically for punch-like tools (e.g. scorpion stings) on thick targets, and for crushing tools (e.g. molars). For punch-like tools on thin targets, and for cutting blades on thick targets, the tip or edge diameters must be even smaller than expected from isometry in smaller animals. The diameters of a small sample of unworn punch-like tools from a large range of animal sizes are consistent with the model, scaling isometrically or more steeply (positively allometric). In addition, we find that the force required to puncture a thin target using real biological tools scales linearly with tip diameter, as predicted by the model. We argue that, for smaller tools, the minimum energy to fracture the tool will be a greater fraction of the minimum energy required to puncture the target, making fracture more likely. Finally, energy stored in tool bending, relative to the energy to fracture the tool, increases rapidly with the aspect ratio (length/width), and we expect that smaller organisms often have to employ higher aspect ratio tools in order to puncture or cut to the required depth with available force. The extra stored energy in higher aspect ratio tools is likely to increase the probability of fracture. We discuss some of the implications of the suggested scaling rules and possible adaptations to compensate for fracture sensitivity in smaller organisms.
Slice–push, formation of grooves and the scale effect in cutting
Authors: Atkins A. G.
Published: April 2016

Three separate aspects of cutting are investigated which complement other papers on the mechanics of separation processes presented at this interdisciplinary Theo Murphy meeting. They apply in all types of cutting whether blades are sharp or blunt, and whether the material being cut is ‘hard, stiff and strong’ or ‘soft, compliant and weak’. The first topic discusses why it is easier to cut when there is motion along (parallel to) the blade as well motion across (perpendicular to) the cutting edge, and the analysis is applied to optimization of blade geometries to produce minimum cutting forces and hence minimum damage to cut surfaces. The second topic concerns cutting with more than one edge with particular application to the formation of grooves in surfaces by hard pointed tools. The mechanics are investigated and applied to the topic of abrasive wear by hard particles. Traditional analyses say that abrasive wear resistance increases monotonically with the hardness of the workpiece, but we show that the fracture toughness of the surface material is also important, and that behaviour is determined by the toughness-to-hardness ratio rather than hardness alone. Scaling forms the third subject. As cutting is a branch of elasto-plastic fracture mechanics, cube-square energy scaling applies in which the important length scale is (
ER
/
k
2
), where
E
is Young's modulus,
R
is the fracture toughness and
k
is the shear yield strength. Whether, in cutting, material is removed as ductile ribbons, as semi-ductile discontinuous chips, or by brittle ‘knocking lumps out’ is shown to depend on the depth of cut relative to this characteristic length parameter. Scaling in biology is called allometry and its relationship with engineering scaling is discussed. Some speculative predictions are made in relation to the action of teeth on food.
In silico serotyping of E. coli from short read data identifies limited novel O-loci but extensive diversity of O:H serotype combinations within and between pathogenic lineages
Authors: Ingle Danielle J. , Valcanis Mary , Kuzevski Alex , Tauschek Marija , Inouye Michael , Stinear Tim , Levine Myron M. , Robins-Browne Roy M. , Holt Kathryn E.
Published: April 2016

The lipopolysaccharide (O) and flagellar (H) surface antigens of Escherichia coli are targets for serotyping that have traditionally been used to identify pathogenic lineages. These surface antigens are important for the survival of E. coli within mammalian hosts. However, traditional serotyping has several limitations, and public health reference laboratories are increasingly moving towards whole genome sequencing (WGS) to characterize bacterial isolates. Here we present a method to rapidly and accurately serotype E. coli isolates from raw, short read WGS data. Our approach bypasses the need for de novo genome assembly by directly screening WGS reads against a curated database of alleles linked to known and novel E. coli O-groups and H-types (the EcOH database) using the software package srst2. We validated the approach by comparing in silico results for 197 enteropathogenic E. coli isolates with those obtained by serological phenotyping in an independent laboratory. We then demonstrated the utility of our method to characterize isolates in public health and clinical settings, and to explore the genetic diversity of >1500 E. coli genomes from multiple sources. Importantly, we showed that transfer of O- and H-antigen loci between E. coli chromosomal backbones is common, with little evidence of constraints by host or pathotype, suggesting that E. coli ‘strain space’ may be virtually unlimited, even within specific pathotypes. Our findings show that serotyping is most useful when used in combination with strain genotyping to characterize microevolution events within an inferred population structure.
Transcriptional bursting explains the noise-versus-mean relationship in mRNA and protein levels
Authors: Dar Roy D. , Schaffer Sydney M. , Dey Siddarth S. , Foley Jonathan E. , Singh Abhyudai , Razooky Brandon S. , Arkin Adam P. , Schafer David V. , Simpson Michael L. , Raj Arjun , Weinberger Leor S.
Published: April 2016

Recent analysis (Dey et al, 2015), demonstrates that the HIV-1 Long Terminal Repeat (HIV LTR) promoter exhibits a range of possible transcriptional burst sizes and frequencies for any mean-expression level. However, these results have also been interpreted as demonstrating that cell-to-cell expression variability (noise) and mean are uncorrelated, a significant deviation from previous results. Here, we re-examine the available mRNA and protein abundance data for the HIV LTR and find that noise in mRNA and protein expression scales inversely with the mean along analytically predicted transcriptional burst-size manifolds. We then experimentally perturb transcriptional activity to test a prediction of the multiple burst-size model: that increasing burst frequency will cause mRNA noise to decrease along given burst-size lines as mRNA levels increase. The data show that mRNA and protein noise decrease as mean expression increases, supporting the canonical inverse correlation between noise and mean.

Conflict of Interest

The authors declare that they have no conflict of interest.
Vasculogenesis Potential of Mesenchymal and Endothelial Stem Cells Isolated from Various Human Tissues
Authors: Rohban Rokhsareh , Etchart Nathalie , Pieber Thomas R.
Published: April 2016

Neo vessel formation can be initiated by co-transplantation of mesenchymal stem cells (MSC) with endothelial colony-forming cells (ECFC). The two adult stem cell types can be isolated and expanded from a variety of tissues to be used for regenerative applications pro-angiogenesis.

Here we performed a systematic study to evaluate the neo-vasculogenesis potential of MSC and ECFC isolated from various human tissues. MSC were isolated, purified and expandedin vitrofrom umbilical cord (UC) and umbilical cord blood (UCB), white adipose tissue (WAT), bone marrow (BM), and amniotic membrane of placenta (AMN).

ECFC were isolated from UC and UCB, WAT and peripheral blood (PB). ECFC and MSC and were co-transplanted admixed with extracellular matrix (Matrigel®) at a ratio of 5:1 to immune-deficient NSG mice, subcutaneously. The transplants were harvested after two weeks and the state of vessel formation and stability in the explants were investigated using immune-histochemical methods. The number of created micro-vessels was quantified using Hematoxylin & Eosin (H&E) staining followed by image J quantification.

Results showed that ECFC and MSC possess variable capacity in contributing to neo-vasculogenesis. WAT and UCB-derived ECFC and WAT, UCB and BM-derived MSC are most potent cells in terms of neo-vessel formationin vivo. UC-derived ECFC and AMN-derived MSC have been shown to be least potent in contributing to neo-vasculogenesis. This variability might be due to variable phenotypes, or different genetic profiles of MSC and ECFC isolated from different tissues and/or donors.

The findings might give an insight into better regenerative strategies for neo-vessel formationin vivo.
Impact of the X Chromosome and sex on regulatory variation
Authors: Kukurba Kimberly R. , Parsana Princy , Balliu Brunilda , Smith Kevin S. , Zappala Zachary , Knowles David A. , Favé Marie-Julie , Davis Joe R. , Li Xin , Zhu Xiaowei , Potash James B. , Weissman Myrna M. , Shi Jianxin , Kundaje Anshul , Levinson Douglas F. , Awadalla Philip , Mostafavi Sara , Battle Alexis , Montgomery Stephen B.
Published: April 2016

The X Chromosome, with its unique mode of inheritance, contributes to differences between the sexes at a molecular level, including sex-specific gene expression and sex-specific impact of genetic variation. Improving our understanding of these differences offers to elucidate the molecular mechanisms underlying sex-specific traits and diseases. However, to date, most studies have either ignored the X Chromosome or had insufficient power to test for the sex-specific impact of genetic variation. By analyzing whole blood transcriptomes of 922 individuals, we have conducted the first large-scale, genome-wide analysis of the impact of both sex and genetic variation on patterns of gene expression, including comparison between the X Chromosome and autosomes. We identified a depletion of expression quantitative trait loci (eQTL) on the X Chromosome, especially among genes under high selective constraint. In contrast, we discovered an enrichment of sex-specific regulatory variants on the X Chromosome. To resolve the molecular mechanisms underlying such effects, we generated chromatin accessibility data through ATAC-sequencing to connect sex-specific chromatin accessibility to sex-specific patterns of expression and regulatory variation. As sex-specific regulatory variants discovered in our study can inform sex differences in heritable disease prevalence, we integrated our data with genome-wide association study data for multiple immune traits identifying several traits with significant sex biases in genetic susceptibilities. Together, our study provides genome-wide insight into how genetic variation, the X Chromosome, and sex shape human gene regulation and disease.
Applications of Bayesian corrections for systematic errors in Rietveld refinements
Authors: Gagin Anton , Levin Igor
Published: April 2016

Recently, a Bayesian statistics approach for correction of systematic errors in Rietveld refinements has been developed and implemented as a patch toGSAS-II. This paper demonstrates the benefits of the proposed method in a series of structural refinements from diffraction data collected for one sample using four different powder diffractometers,i.e.synchrotron and laboratory X-ray and two time-of-flight neutron instruments. Differences between the parameters estimated while fitting these four data sets provided magnitudes of the systematic errors while also highlighting the efficacy of the Bayesian procedure for their correction. Structural parameters estimated from the standard Rietveld refinements using the four data sets differed significantly. In all cases, the agreement improved markedly after applying the Bayesian error-correction procedure. The Bayesian refinements were paired with a Markov chain Monte Carlo algorithm, which was implemented as part of the same patch toGSAS-II, to confirm that uncertainties in the refined parameters obtained using the much faster least-squares minimization were realistic.