2,225 research outputs found
Development of Multiple Polymorphic Microsatellite Markers for Ceratina calcarata (Hymenoptera: Apidae) Using Genome-Wide Analysis
The small carpenter bee, Ceratina calcarata (Robertson), is a widespread native pollinator across eastern North America. The behavioral ecology and nesting biology of C. calcarata has been relatively well-studied and the species is emerging as a model organism for both native pollinator and social evolution research. C. calcarata is subsocial: reproductively mature females provide extended maternal care to their brood. As such, studies of C. calcarata may also reveal patterns of relatedness and demography unique to primitively social Hymenoptera. Here, we present 21 microsatellite loci, isolated from the recently completed C. calcarata genome. Screening in 39 individuals across their distribution revealed that no loci were in linkage disequilibrium, nor did any deviate significantly from Hardy-Weinberg following sequential Bonferroni correction. Allele count ranged from 2 to 14, and observed and expected heterozygosities ranged from 0.08 to 0.82 (mean 0.47) and 0.26 to 0.88 (mean 0.56), respectively. These markers will enable studies of population-wide genetic structuring across C. calcarata’s distribution. Such tools will also allow for exploration of between and within-colony relatedness in this subsocial native pollinator
Treatment Strategies for Refractory Diabetic Macular Edema: Switching Anti-VEGF Treatments, adopting corticosteroid-based treatments, and combination therapy
Introduction: The pathophysiology of diabetic macular edema (DME) is complex, involving vascular endothelial growth factor (VEGF) and other inflammatory mediators. DME is currently treated first-line with intravitreal anti-VEGF treatments, though some cases are refractory to multiple anti-VEGF treatments.
Areas covered: This article examines the evolution of treatment practices for DME, with discussion of the recent studies that guide treatment for refractory cases of DME. A literature search was performed using the following terms: anti-VEGF, DME, aflibercept, bevacizumab, ranibizumab, refractory macular edema, and VEGF.
Expert opinion: Focal extrafoveal DME may be treated first-line with laser. In patients with center-involving DME and only mild vision loss, consider starting treatment with bevacizumab, especially when cost is an issue, whereas aflibercept may be considered more strongly in patients with moderate visual loss or worse. There are no standard protocols that define ‘treatment failure,’ but several studies have reported that switching from bevacizumab to either ranibizumab or aflibercept will result in further reduction of CSFT and improvement in BCVA. Further study with prospective randomized trials is warranted to validate these findings. Switching to intravitreal corticosteroids may be of particular benefit to pseudophakic patients. Anti-VEGF combination with sustained-release corticosteroids also appears promising for refractory DME
Analysis of Unsteady Squeezing Flow Between Two Porous Plates With Variable Magnetic Field
Analysis will be made for the non-isothermal Newtonian fuid flow between two unsteady squeezing porous plates under the infuence of variable magnetic feld. The similarity transformations will be used to transform the partial differential equations into nonlinear coupled ordinary differential equations. The modeled nonlinear differential equations representing the flow behavior in the geometry under consideration will be investigated using analytical and numerical method. Comparison of the solutions will be made. Convergence of solution will also be discussed. Flow behavior under the infuence of non-dimensional parameters will be discussed with the help of graphical aids
Highly Quantum-Confined InAs Nanoscale Membranes
Nanoscale size-effects drastically alter the fundamental properties of
semiconductors. Here, we investigate the dominant role of quantum confinement
in the field-effect device properties of free-standing InAs nanomembranes with
varied thicknesses of 5-50 nm. First, optical absorption studies are performed
by transferring InAs "quantum membranes" (QMs) onto transparent substrates,
from which the quantized sub-bands are directly visualized. These sub-bands
determine the contact resistance of the system with the experimental values
consistent with the expected number of quantum transport modes available for a
given thickness. Finally, the effective electron mobility of InAs QMs is shown
to exhibit anomalous field- and thickness-dependences that are in distinct
contrast to the conventional MOSFET models, arising from the strong quantum
confinement of carriers. The results provide an important advance towards
establishing the fundamental device physics of 2-D semiconductors
Ranibizumab For Diabetic Macular Edema Refractory To Multiple Prior Treatments
Purpose: Diabetic macular edema can be refractory to multiple treatment modalities. Although there have been anecdotal reports of ranibizumab showing efficacy when other modalities provided limited benefit, little has been published on treatment for refractory diabetic macular edema. This study sought to investigate this observation further.
Methods: Retrospective chart review.
Results: Thirty-three eyes of 22 patients with refractory diabetic macular edema were treated with 0.3 mg intravitreal ranibizumab. This group of eyes received an average of 5.1 prior treatments (macular laser, intravitreal bevacizumab, triamcinolone acetonide, or dexamethasone implant). The mean best corrected visual acuity before the initial ranibizumab injection was 20/110 and the mean central subfield thickness was 384 μm. After 7 visits over an average of 48 weeks, during which an average of 6 ranibizumab injections were administered, the mean visual acuity improved to 20/90 and the mean central subfield thickness improved to 335 μm. Both central subfield thickness and best corrected visual acuity improved with number of days of follow-up in a statistically significant fashion (P < 0.01). Similarly, both central subfield thickness and visual acuity improved with number of ranibizumab injections in a linear fashion, but this was not statistically significant.
Conclusion: Ranibizumab can improve diabetic macular edema refractory to prior treatments of laser photocoagulation, intravitreal triamcinolone acetonide, and bevacizumab
Chorioretinal Coloboma Complications: Retinal Detachment and Choroidal Neovascular Membrane
PURPOSE:
To report the chorioretinal coloboma, and its association with increased risk of retinal detachment (RD) and choroidal neovascularization (CNV).
METHODS:
This retrospective case series included eyes with chorioretinal coloboma diagnosed between 1995 and 2014 with a focus on RD and CNV as related complications. Cases of CNV were managed with laser photocoagulation or intravitreal injection of bevacizumab. For eyes with CNV, therapeutic success was defined as resolution of the subretinal hemorrhage on fundus examination and resolution of the subretinal and intraretinal fluid on optical coherence tomography (OCT). For eyes with RD, anatomic success following surgical intervention was defined as attachment of the retina at the last follow-up visit.
RESULTS:
Fifty-one eyes of 31 patients with chorioretinal coloboma were identified for review. Bilateral chorioretinal coloboma was present in 64.5% of subjects. RD developed in 15 eyes (29.4%). Among 15 eyes with RD, 4 eyes (27%) had retinal breaks identified within the coloboma, 5 eyes (33%) had retinal breaks outside the coloboma, 2 eyes (13%) showed retinal breaks both inside and outside the coloboma, and in 4 eyes (27%) the causative retinal break was not localized. The overall rate of anatomic success after RD repair was 85.7%. CNV developed in 7 eyes (13.7%) and was located along the margin of the coloboma in all cases. CNV was bilateral in 2 of the 5 affected individuals (40%).
CONCLUSION:
RD and CNV were present in a high percentage of eyes with chorioretinal coloboma in these series. The frequent finding of retinal breaks outside the coloboma bed suggests that vitreoretinal interface abnormalities may play a role in development of RD in these eyes
Analysis of Physiochemical Parameters to Evaluate the Drinking Water Quality in the State of Perak, Malaysia
YesThe drinking water quality was investigated in suspected parts of Perak state, Malaysia, to ensure the continuous supply of clean and safe drinking water for the public health protection. In this regard, a detailed physical and chemical analysis of drinking water samples was carried out in different residential and commercial areas of the state. A number of parameters such as pH, turbidity, conductivity, total suspended solids (TSS), total dissolved solids (TDS), and heavy metals such as Cu, Zn, Mg, Fe, Cd, Pb, Cr, As, Hg, and Sn were analysed for each water sample collected during winter and summer periods. The obtained values of each parameter were compared with the standard values set by the World Health Organization (WHO) and local standards such as National Drinking Water Quality Standard (NDWQS). The values of each parameter were found to be within the safe limits set by the WHO and NDWQS. Overall, the water from all the locations was found to be safe as drinking water. However, it is also important to investigate other potential water contaminations such as chemicals and microbial and radiological materials for a longer period of time, including human body fluids, in order to assess the overall water quality of Perak state
Ideal Bandgap in a 2D Ruddlesden-Popper Perovskite Chalcogenide for Single-junction Solar Cells
Transition metal perovskite chalcogenides (TMPCs) are explored as stable,
environmentally friendly semiconductors for solar energy conversion. They can
be viewed as the inorganic alternatives to hybrid halide perovskites, and
chalcogenide counterparts of perovskite oxides with desirable optoelectronic
properties in the visible and infrared part of the electromagnetic spectrum.
Past theoretical studies have predicted large absorption coefficient, desirable
defect characteristics, and bulk photovoltaic effect in TMPCs. Despite recent
progresses in polycrystalline synthesis and measurements of their optical
properties, it is necessary to grow these materials in high crystalline quality
to develop a fundamental understanding of their optical properties and evaluate
their suitability for photovoltaic application. Here, we report the growth of
single crystals of a two-dimensional (2D) perovskite chalcogenide, Ba3Zr2S7,
with a natural superlattice-like structure of alternating double-layer
perovskite blocks and single-layer rock salt structure. The material
demonstrated a bright photoluminescence peak at 1.28 eV with a large external
luminescence efficiency of up to 0.15%. We performed time-resolved
photoluminescence spectroscopy on these crystals and obtained an effective
recombination time of ~65 ns. These results clearly show that 2D
Ruddlesden-Popper phases of perovskite chalcogenides are promising materials to
achieve single-junction solar cells.Comment: 4 Figure
Fabrication of 316L stainless steel (SS316L) foam via powder compaction method
Metal foam is the cellular structures that made from metal and have pores in their
structures. Metal foam also known as the porous metals, which express that the
structure has a large volume of porosities with the value of up to 0.98 or 0.99. Porous
316L stainless steel was fabricated by powder metallurgy route with the composition
of the SS316L metal powder as metallic material, polyethylene glycol (PEG) and
Carbamide as the space holder with the composition of 95, 90, 85, 80, and 75 of
weight percent (wt. %). The powders were mixed in a ball mill at 60 rpm for 10
minutes and the mixtures were put into the mold for the pressing. The samples were
uniaxially pressed at 3 tons and heat treated by using box furnace at different
sintering temperature which are 870°C, 920°C, and 970°C separately. The suitable
sintering temperature was obtained from the Thermal Gravimetric Analysis (TGA).
There are several tests that have been conducted in order to characterize the physical
properties of metal foam such as density and porosity testing, and the morphological
testing (Scanning Electron Microscopy (SEM)), and Energy Dispersive X-ray (EDX).
From the result, it can be conclude that, the sintering temperature of 920°C was
compatible temperature in order to produce the metal foams which have large pores.
Other than that, the composition of 85 and 75 wt. % is the best compositions in order
to creates the homogenous mixture and allow the formation of large pore uniformly
compared to other compositions which in line with the objective to produce foams
with low density and high porosity which suitable for implant applications. The
average pore size was within range 38.555μm to 54.498 μm which can be classified
as micro pores
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