bluuebunny/crossref_metadata_2025_split huggingface dataset:
Common Eye Diseases in Children in Saudi Arabia (Jazan)
Authors: Darraj Abdulrahman , Barakat Walid , Kenani Mona , Shajry Reem , Khawaji Abdullah , Bakri Sultan , Makin Abdulrahman , Mohanna Azza , Yassin Abu Obaida 
Published: September 2016

Background The rise in childhood eye diseases has become a matter of concern in Saudi Arabia, and hence a study has been conducted on the residents of Jazan. The aim of the research was to find out the root cause of such issues and provide a solution to prevent such circumstances for it may affect the vision of children. In this study, therefore, we aimed to determine the types of childhood eye diseases in Jazan and to discuss the best ways to prevent them or prevent their effect on the vision of our children. Our institutions are working toward the longevity and welfare of the residents, and healthcare is one of the important aspects in such a field. Methods This is a retrospective review of all patients less than 18 years of age who presented to the pediatric ophthalmology clinic of Prince Mohammed Bin Nasser Hospital, Jazan, between October 2014 and October 2015. The data, collected on 385 cases, included the age at first presentation, sex, clinical diagnosis, refractive error (RE) if present, and whether the child had amblyopia. If the child did not undergo complete ophthalmic examination with cycloplegic refraction, he/she was excluded. All data were collected and analyzed using the software SPSS. A P-value < 0.05 was considered statistically significant. Results We reviewed the files of 385 children, with a male/female ratio of 1.1:1.0. The group aged 0–6 years made up the largest group ( P = 0.01), and the ratio is an expression to define the credibility of the study using a chi-squared test. Strabismus (36.9%), RE (26.5%), ocular trauma (7.5%), infection of cornea and conjunctiva (7.3%), and keratoconus (6.2%) were the most common conditions. There was no significant difference in presentation by age group and sex among children with REs and squint. Trauma was seen more commonly among males and in the group aged 12–18 years. Conclusion In this retrospective study, the focus was on the common childhood eye diseases that were considerably high. Hypermetropia was the predominant RE, which is in contrast to other studies where myopia was more common. However, it is important to promote public education on the significance of early detection of strabismus, REs, and amblyopia and have periodic screening in schools. The discussion of the various issues is aimed at increasing the awareness and building a support for the cause by creating the knowledge base to treat things on time and acknowledging the severity of the issues.
Didáctica de las matemáticas y arquitectura: la razón áurea en la Lonja de Valencia
Authors: Donat Paula , Rueda Pilar , Sánchez-Pérez Enrique Alfonso 
Published: September 2016

El objetivo del presente trabajo es doble. Por una parte, se pretende estructurar y relatar una experiencia docente de tutorización de un trabajo fin de grado de Matemáticas de la Universidad de Valencia. La característica principal del proyecto es que trata sobre ciertas propiedades geométricas de un edificio emblemático de la ciudad de Valencia. Concretamente se trata de analizar el proceso de planteamiento, concreción, documentación y elaboración del trabajo fin de grado seguido en dicha experiencia. Por otro lado, se pretende también analizar la metodología seguida para la obtención y valoración de los resultados derivados de una de las partes fundamentales del trabajo en cuestión: la descomposición armónica del edificio de la Lonja de la Seda en Valencia.<br /><br />
Ground-based imaging remote sensing of ice clouds: uncertainties caused by sensor, method and atmosphere
Authors: Zinner Tobias , Hausmann Petra , Ewald Florian , Bugliaro Luca , Emde Claudia , Mayer Bernhard 
Published: September 2016

Abstract. In this study a method is introduced for the retrieval of optical thickness and effective particle size of ice clouds over a wide range of optical thickness from ground-based transmitted radiance measurements. Low optical thickness of cirrus clouds and their complex microphysics present a challenge for cloud remote sensing. In transmittance, the relationship between optical depth and radiance is ambiguous. To resolve this ambiguity the retrieval utilizes the spectral slope of radiance between 485 and 560 nm in addition to the commonly employed combination of a visible and a short-wave infrared wavelength.An extensive test of retrieval sensitivity was conducted using synthetic test spectra in which all parameters introducing uncertainty into the retrieval were varied systematically: ice crystal habit and aerosol properties, instrument noise, calibration uncertainty and the interpolation in the lookup table required by the retrieval process. The most important source of errors identified are uncertainties due to habit assumption: Averaged over all test spectra, systematic biases in the effective radius retrieval of several micrometre can arise. The statistical uncertainties of any individual retrieval can easily exceed 10 µm. Optical thickness biases are mostly below 1, while statistical uncertainties are in the range of 1 to 2.5.For demonstration and comparison to satellite data the retrieval is applied to observations by the Munich hyperspectral imager specMACS (spectrometer of the Munich Aerosol and Cloud Scanner) at the Schneefernerhaus observatory (2650 m a.s.l.) during the ACRIDICON-Zugspitze campaign in September and October 2012. Results are compared to MODIS and SEVIRI satellite-based cirrus retrievals (ACRIDICON – Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems; MODIS – Moderate Resolution Imaging Spectroradiometer; SEVIRI – Spinning Enhanced Visible and Infrared Imager). Considering the identified uncertainties for our ground-based approach and for the satellite retrievals, the comparison shows good agreement within the range of natural variability of the cloud situation in the direct surrounding.
Exploring water cycle dynamics by sampling multiple stable water isotope
pools in a developed landscape in Germany
Authors: Orlowski Natalie , Kraft Philipp , Pferdmenges Jakob , Breuer Lutz 
Published: September 2016

Abstract. A dual stable water isotope (δ2H and δ18O) study was conducted in the developed (managed) landscape of the Schwingbach catchment (Germany). The 2-year weekly to biweekly measurements of precipitation, stream, and groundwater isotopes revealed that surface and groundwater are isotopically disconnected from the annual precipitation cycle but showed bidirectional interactions between each other. Apparently, snowmelt played a fundamental role for groundwater recharge explaining the observed differences to precipitation δ values. A spatially distributed snapshot sampling of soil water isotopes at two soil depths at 52 sampling points across different land uses (arable land, forest, and grassland) revealed that topsoil isotopic signatures were similar to the precipitation input signal. Preferential water flow paths occurred under forested soils, explaining the isotopic similarities between top- and subsoil isotopic signatures. Due to human-impacted agricultural land use (tilling and compression) of arable and grassland soils, water delivery to the deeper soil layers was reduced, resulting in significant different isotopic signatures. However, the land use influence became less pronounced with depth and soil water approached groundwater δ values. Seasonally tracing stable water isotopes through soil profiles showed that the influence of new percolating soil water decreased with depth as no remarkable seasonality in soil isotopic signatures was obvious at depths > 0.9 m and constant values were observed through space and time. Since classic isotope evaluation methods such as transfer-function-based mean transit time calculations did not provide a good fit between the observed and calculated data, we established a hydrological model to estimate spatially distributed groundwater ages and flow directions within the Vollnkirchener Bach subcatchment. Our model revealed that complex age dynamics exist within the subcatchment and that much of the runoff must has been stored for much longer than event water (average water age is 16 years). Tracing stable water isotopes through the water cycle in combination with our hydrological model was valuable for determining interactions between different water cycle components and unravelling age dynamics within the study area. This knowledge can further improve catchment-specific process understanding of developed, human-impacted landscapes.
Scheimpflug Image-Based Changes in Anterior Segment Parameters during Accommodation Induced by Short-Term Reading
Authors: Lipecz Agnes , Tsorbatzoglou Alexis , Hassan Ziad , Berta Andras , Modis Laszlo , Nemeth Gabor 
Published: September 2016

Purpose To analyze the effect of the accommodation on the anterior segment data (corneal and anterior chamber parameters) induced by short-time reading in a healthy, nonpresbyopic adult patient group. Methods Images of both eyes of nonpresbyopic volunteers were captured with a Scheimpflug device (Pentacam HR) in a nonaccommodative state. Fifteen minutes of reading followed and through fixation of the built-in target of Pentacam HR further accommodation was achieved and new images were captured by the device. Anterior segment parameters were observed and the differences were analyzed. Results Fifty-two healthy eyes of 26 subjects (range 20.04-28.58 years) were analyzed. No significant differences were observed in the keratometric values before and after the accommodative task (p = 0.35). A statistically significant difference was measured in the 5.0-mm-diameter and the 7.0-mm-diameter corneal volume (p = 0.01 and p = 0.03) between accommodation states. Corneal aberrometric data did not change significantly during short-term accommodation. Significant differences were observed between nonaccommodative and accommodative states of the eyes for all measured anterior chamber parameters. Conclusions Among the parameters of the cornea, only corneal volume changed during the short-term accommodation process, showing some fine changes with accommodation of the cornea in young, emmetropic patients. The position of the pupil and the anterior chamber parameters were observed to change with accommodation as captured by a Scheimpflug device.
Safety and Efficacy of Collagen Matrix Implantation in Infantile Glaucoma
Authors: Elhefney Eman M. , Al-Sharkawy Hossam T. , Kishk Hanem M. , Abouelkheir Hossam 
Published: September 2016

Purpose To evaluate the preliminary results of biodegradable collagen matrix implant (Ologen) designed to improve outcome in patients with infantile glaucoma undergoing combined trabeculotomy and trabeculectomy. Methods A biodegradable collagen matrix (OculusGen) was placed in the subconjunctival space, partially over the scleral flap and the sclera in 20 eyes of 11 patients with infantile glaucoma who underwent combined trabeculotomy and trabeculectomy. Patients were examined preoperatively and on the first postoperative day with multiple postoperative follow-up visits within 12 months after surgery. Examination included measurements of intraocular pressure (IOP), corneal diameter, and axial length, bleb evaluation, and funduscopy. Ultrasound biomicroscopy of bleb (bleb presence, wall reflectivity, and scleral route visibility) was done at 1, 3, and 6 months and the last follow-up visit. Any complication was recorded. Data analysis was performed using paired-samples t test. Results Mean patient age was 5.7 ± 5.69 months. Mean duration of follow-up was 10.05 ± 1.15 months. Mean preoperative IOP was 25.9 ± 3.08 mm Hg with 1.75 ± 0.55 IOP-lowering medications and mean final postoperative IOP was 17.7 ± 3.51 mm Hg with 0.55 ± 0.69 IOP-lowering medications. Overall success at last follow-up was 80%. None of the patients experienced systemic or ocular complication related to OculusGen. By the 6th month, complete Ologen degradation was evident in all cases. Conclusions The short-term preliminary results of this study indicate that the combined trabeculotomy and trabeculectomy with Ologen implantation could potentially provide a safe and effective procedure in the infantile age group but longer duration of follow-up in larger number of patients is needed.
Relationship between Intraocular Pressure and Anterior Lamina Cribrosa Depth: A Cross-Sectional Observational Study in a Healthy Portuguese Population
Authors: Sousa David Cordeiro , Leal Inês , Marques-Neves Carlos , Pinto Filomena , Abegão Pinto Luís 
Published: September 2016

Purpose To investigate the association between anterior lamina cribrosa depth (ALCD), determined with enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT), and intraocular pressure (IOP) in a healthy Portuguese population. Methods In this cross-sectional observational study conducted between January and July 2015, 2 optic nerve head (ONH)–centered EDI-OCT cross-scans were performed and ALCD was defined as the perpendicular distance between the line connecting both edges of Bruch's membrane opening and the anterior border of the lamina cribrosa at the maximum depth point. A multivariate regression model was performed to assess the association of IOP and ALCD. Results The studied population included 59 subjects (35 women) with a mean age of 61.7 ± 15.1 years. Mean vertical and horizontal maximum ALCD was 444.5 ± 92.2 μm and 427.6 ± 82.7 μm, respectively. When controlling for age and spherical equivalent, maximum vertical and horizontal ALCD were positively correlated with intraocular pressure (R2>0.20) by 8.58 μm (95% confidence interval [CI] 2.80-14.36 μm; p<0.01) and 8.25 μm (95% CI 2.71-13.78 μm; p<0.01) per mm Hg of IOP, respectively. Conclusions Our sample of healthy subjects presented a statistically significant positive correlation between IOP and ALCD when controlling for possible confounding factors. These results may trigger further studies to better elucidate the role of IOP in the morphologic and functional dynamics of the ONH.
Surgical Repair of Large Cyclodialysis Clefts
Authors: Gross Jacob B. , Davis Garvin H. , Bell Nicholas P. , Feldman Robert M. , Blieden Lauren S. 
Published: September 2016

Purpose To describe a new surgical technique to effectively close large (>180 degrees) cyclodialysis clefts. Methods Our method involves the use of procedures commonly associated with repair of retinal detachment and complex cataract extraction: phacoemulsification with placement of a capsular tension ring followed by pars plana vitrectomy and gas tamponade with light cryotherapy. We also used anterior segment optical coherence tomography (OCT) as a noninvasive mechanism to determine the extent of the clefts and compared those results with ultrasound biomicroscopy (UBM) and gonioscopy. Results This technique was used to repair large cyclodialysis clefts in 4 eyes. All 4 eyes had resolution of hypotony and improvement of visual acuity. One patient had an intraocular pressure spike requiring further surgical intervention. Anterior segment OCT imaging in all 4 patients showed a more extensive cleft than UBM or gonioscopy. Conclusions This technique is effective in repairing large cyclodialysis clefts. Anterior segment OCT more accurately predicted the extent of each cleft, while UBM and gonioscopy both underestimated the size of the cleft.
Major Acetabular Defects Treated with the Burch-Schneider Antiprotrusion Cage and Impaction Bone Allograft in a Large Series: A 5- to 7- Year Follow-up Study
Authors: Marx Axel , Beier Alexander , Richter Anne , Lohmann Christoph H. , Halder Andreas M. 
Published: September 2016

Introduction Major bone defects are the greatest challenge in hip revision arthroplasty. Methods In a prospective, consecutive nonrandomised study we followed up 74 patients with Type III (AAOS) acetabular bone defects who underwent revision hip arthroplasty with bone grafting and implantation of a Burch-Schneider anti-protrusion cage (APC). The patients were examined pre- and postoperatively according to a standardised clinical and radiological protocol. No patient was lost to follow-up. Results 9 patients died before follow-up. In 9 other patients the APC was revised within the follow-up period. In 4 of these patients the revision was necessary because of aseptic loosening. In the remaining 5 cases joint infection, recurrent dislocation and 1 trauma were the reasons for revision. 56 patients were included in the statistical analysis. In the follow-up group the mean Harris Hip Score increased from 39.9 preoperatively to 73.2. 85% of the patients assessed their operation result as good or excellent. Conclusions In a large consecutive series the Burch-Schneider anti-protrusion cage proved to be a valuable option in the treatment of major acetabular bone defects in hip revision surgery.
An Unusual Cause of Neonatal HIP Dislocation: Infantile Myofibromatosis Presenting as Developmental Dysplasia of the HIP
Authors: Woo Timothy , Win Thuzar 
Published: September 2016

Introduction Infantile myofibromatosis (IM) is a rare paediatric fibrous tumour also known as a desmoid tumour that occurs in around 1:150000 live births. It manifests as solitary or multicentric fibrous masses in the musculoaponeurotic soft tissues and can affect the visceral organs and bones. Case discussion We report a case of infantile myofibromatosis of the gluteus maximus muscle in an 18-day old neonate presenting atypically as a case of developmental dysplasia of the hip due to local involvement of the sciatic nerve. However, failure of improvement with conventional management and clinical wasting of the lower leg muscles was indicative of a secondary cause of the patient's hip dislocation, which was confirmed on imaging and surgical biopsy. Discussion This case report aims to emphasise the importance of considering secondary causes of neonatal hip dislocation, especially in cases where imaging findings are atypical of conventional DDH. Although imaging appearances on ultrasound and CT may vary, the signal characteristics and enhancement pattern of soft tissue myofibromata on MRI with and without gadolinium contrast appear to be the most consistent finding in these cases.
Poly (L-Lactic Acid) Porous Scaffold-Supported Alginate Hydrogel with Improved Mechanical Properties and Biocompatibility
Authors: Chu Jiaqi , Zeng Shaodong , Gao Liyang , Groth Thomas , Li Zhiwen , Kong Junchao , Zhao Mingyan , Li Lihua 
Published: September 2016

Purpose Polymer porous scaffolds and hydrogels have been separately employed and explored for a wide range of applications including cell encapsulation, drug delivery, and tissue engineering. Methods In this study, a three-dimensional poly (L-lactic acid) (PLLA) scaffold with interconnected and homogeneously distributed pores was fabricated to support the alginate hydrogel (Alg). The gels were filled into the porous scaffold, which acted as an analogue of native extracellular matrix (ECM) for entrapment of cells within a support of predefined shape. The mechanical strength of the composite scaffold was characterized by compression testing. The chondrocyte behavior in the scaffold was determined by inverted microscopy, scanning electron microscopy (SEM) and MTT viability assay. The repair efficiency of such a composite scaffold was further investigated in dog spinal defects by histological evaluation after implantation for 4 weeks. Results Results showed that the composite scaffold possessed superior mechanical properties and hierarchical porous structure in comparison to pure Alg. Cell culture revealed that the cells presented a specific cartilage status in the composite scaffold in line with higher adherence and proliferation ratio. The histological analyses suggested that the composite scaffold substantially promotes its integration in the host tissue accompanied with a low inflammatory reaction and new tissue formation. Conclusions The method thus provides a useful pathway for scaffold preparation that can simultaneously achieve suitable mechanical properties and good biocompatibility.
Shear Bond Strengths of Brackets Bonded with a New Self-Adhering Resin Composite
Authors: Gungor Ahmet Yalcin , Alkis Huseyin , Turkkahraman Hakan 
Published: September 2016

Purpose To determine the shear bond strength (SBS) of orthodontic brackets bonded with a self-adhering resin composite. Methods 45 freshly extracted mandibular incisors were randomly divided into 3 groups (n = 15 per group). Brackets were bonded with 3 bonding systems and cured with an LED light. Brackets were bonded with a new self-adhering resin cement in the study group. A conventional etch-and-rinse adhesive system and a self-etching adhesive system were used for comparison. After bonding, the SBS of the brackets were tested with a universal testing machine. Results Analysis of variance indicated a significant difference between groups (p<0.001). The highest values for SBS were measured in group I (21.80 ± 2.57 MPa). The SBS was significantly lower in groups II and III than in group I (P<.001). The lowest values for SBS were measured in group III (5.90 ± 0.90 MPa). SBS was significantly higher in group II than in group III (p<0.001). Conclusions The self-adhering adhesive system showed a clinically insufficient SBS, whereas the SBS of conventional etch-and-rinse adhesive system and the self-etching adhesive system were significantly higher and clinically sufficient.
Optimisation of the Sputnik-VAD Design
Authors: Selishchev Sergey V. , Telyshev Dmitry V. 
Published: September 2016

Purpose Miniaturisation of VADs can offer important benefits, including less invasive implantation techniques and more versatility in patient selection. The aim of this work was to reduce the weight, size, and energy consumption of the Sputnik VAD. Methods The second generation of the Sputnik VAD was developed with a set of changes in construction. The head pressure-flow rate (H-Q) and power consumption-flow rate curves for the Sputnik VADs were measured at different rotational speeds. Computational fluid dynamics (CFD) were used for operating condition simulation and the LVADs were compared under the simulated physiological conditions. Results The slope of the H-Q curves for the Sputnik 1 VAD remains almost invariable over the entire range of the measured flow rate, in contrast to the curves for the Sputnik 2 VAD, which become flat in the high flow-rate region. Despite the design modification, the operating rotor speed remained invariable. The preload sensitivity of the Sputnik VAD is higher than that of the other rotary blood pumps and amounts to 0.111 ± 0.0092 L min−1 mmHg−1. The power consumption for the Sputnik 2 VAD is lower over the entire speed range, except for at 5,000 rpm. Conclusions The pump weight was reduced from 246 to 205 g, the pump length was decreased from 82 to 66 mm, and the pump diameter was decreased from 32 to 29 mm. The total energy consumption of the pump was reduced by 15%.