67 research outputs found
Towards a Prosperous Future for our Children and Nation
Invited Commentary on A Multidisciplinary Team Experience with Food Insecurity and Failure to Thrive by Drs. Kersten and Bennett
Photoluminescence study of Sr3Y1-X(BO3)3:xTb3+ green emitting phosphor
Terbium doped strontium yttrium borate phosphor is prepared by solution combustion method. Structural characterization of Sr3Y(BO3)3:Tb3+ (SYB:Tb) has been carried out with X-ray powder diffraction (XRD) analysis. Particle size of 0.5–2 µm and perfect element composition were seen in SEM-EDS. Using FTIR at room temperature the presence of [BO3]- group; complete combustion of nitrates, organic material, absence of O-H bond were firmed up. Photoluminescence properties of the phosphor have been investigated by measuring the excitation and emission spectra. Several luminescence bands of Tb3+ ions are observed under 233 nm excitation wavelengths in 350–700 nm spectral region. The emission spectra were composed of three bands, in which the dominated emission of green luminescence SYB:Tb attributed to the transition 5D4→7F5 is centered at 543 nm. The dependence of the emission intensity on the Tb3+ concentration for the Sr3Y1-X(BO3)3:xTb3+ (0.01 ≤ x ≤ 0.05) was studied and observed that the optimum concentration of Tb3+ in phosphor was 3 mol% for the highest emission intensity at 543 nm. The CIE coordinates (X=0.251363409, Y=0.736605581) fall at the border of green region in the CIE 1931 chromaticity
Photoluminescence study of Sr3Y1-X(BO3)3:xTb3+ green emitting phosphor
143-147Terbium doped strontium yttrium borate phosphor is prepared by solution combustion method. Structural characterization of Sr3Y(BO3)3:Tb3+ (SYB:Tb) has been carried out with X-ray powder diffraction (XRD) analysis. Particle size of 0.5–2 µm and perfect element composition were seen in SEM-EDS. Using FTIR at room temperature the presence of [BO3]- group; complete combustion of nitrates, organic material, absence of O-H bond were firmed up. Photoluminescence properties of the phosphor have been investigated by measuring the excitation and emission spectra. Several luminescence bands of Tb3+ ions are observed under 233 nm excitation wavelengths in 350–700 nm spectral region. The emission spectra were composed of three bands, in which the dominated emission of green luminescence SYB:Tb attributed to the transition 5D4→7F5 is centered at 543 nm. The dependence of the emission intensity on the Tb3+ concentration for the Sr3Y1-X(BO3)3:xTb3+ (0.01 ≤ x ≤ 0.05) was studied and observed that the optimum concentration of Tb3+ in phosphor was 3 mol% for the highest emission intensity at 543 nm. The CIE coordinates (X=0.251363409, Y=0.736605581) fall at the border of green region in the CIE 1931 chromaticity
Adenocarcinoma of the caecum metastatic to the bladder: an unusual cause of haematuria
BACKGROUND: Primary malignancies of colorectal origin can metastasise to the bladder. Reports are however extremely rare, particularly from the caecum. CASE REPORT: The report describes the case of a 45-year old male with Duke's B caecal carcinoma treated with a laparoscopically-assisted right hemicolectomy and adjuvant 5-Fluorouracil chemotherapy. Subsequently, a metastatic lesion to the bladder was demonstrated and successfully excised by partial cystectomy. CONCLUSION: In order that optimal therapeutic options can be determined, it is important for clinicians to distinguish between primary disease of the bladder and other causes of haematuria. Various immunohistochemical techniques attempt to differentiate primary adenocarcinoma of the bladder from secondary colorectal adenocarcinoma. Suspicion of metastatic disease must be raised when histologically unusual bladder tumours are identified
A novel ceramic coating for reduced metal ion release in metal-on-metal hip surgery
Abstract: An ovine total hip arthroplasty model was developed to evaluate metal ion release, wear, the biological response and adverse tissue reaction to metal-on-metal (MoM) bearing materials. The performance of an advanced superlattice ceramic coating (SLC) was evaluated as a bearing surface and experimental groups divided into; (1) MoM articulating surfaces coated with a SLC coating (SLC-MoM), (2) uncoated
MoM surfaces (MoM), and (3) metal on polyethylene (MoP) surfaces. Implants remained in vivo for 13 months and blood chromium (Cr) and cobalt (Co) metal ion levels were measured pre and postoperatively. Synovial tissue was graded using an ALVAL scoring system. When compared with the MoM group, sheep with SLC-MoM implants showed significantly lower levels of chromium and cobalt metal ions within blood over the 13-month period. Evidence of gray tissue staining was observed in the synovium of implants in the MOM group. A significantly lower ALVAL score was measured in the SLCMoM group (3.88) when compared with MoM components (6.67) (p = 0.010). ALVAL results showed no significant difference when SLC-MOM components were compared to MoP (5.25). This model was able to distinguish wear and the effect of released debris between different bearing combinations and demonstrated the effect of a SLC coating when applied onto the bearing surface
Distribution of glucocorticoid receptors and 11 beta-hydroxysteroid dehydrogenase isoforms in the rat inner ear.
11β-hydroxysteroid dehydrogenase (11β-HSD) is an enzyme complex responsible for the conversion of hormonally active cortisol to inactive cortisone, and two isoforms of the enzyme (11β-HSD1 and 11β-HSD2) have been cloned and characterized. An immunohistochemical study was performed to determine the precise distribution of glucocorticoid receptors (GRs) and the isoforms of 11β-HSD in the rat (postnatal day 1, 4, 10, and adult). Immunoreactivity of GRs was detected in the stria vascularis (SV), the outer hair cells (OHCs), the inner hair cells (IHCs), the spiral ligament (SLig), the spiral limbus (SLib), the spiral ganglion cells (SGCs), Reissner\u27s membrane (RM), the cochlear nerve (CN), the vestibular hair cells (VHCs), the dark cells (DCs), and the vestibular nerve (VN) in the rats. Immunostaining of 11β-HSD1 was observed in almost all the tissues in the cochlea and the vestibule except SLig, SLib, SGCs, CN, VHCs, and VN during all developmental stages, whereas, immunoreactivity of 11β-HSD2 was not detected in any of the inner ear tissues. A polymerase chain reaction (PCR) study was also performed on GRs, 11β-HSD1, and 11β-HSD2 in the OC, SV and vestibule of the postnatal rats, and revealed that mRNAs were detected in all those and tissues in all the developmental days of postnatal days 1, 4, and 10. This data indicates that expression of GRs and 11β-HSD isoforms in the inner ear is tissue and age-specific, and that different local steroid regulation by GRs and the isoforms of 11β-HSD is present in each part of the inner ear
Drug diffusion along an intact mammalian cochlea
Intratympanic drug administration depends on the ability of drugs to pass through the round window membrane (RW) at the base of the cochlea and diffuse from this location to the apex. While the RW permeability for many different drugs can be promoted, passive diffusion along the narrowing spiral of the cochlea is limited. Earlier measurements of the distribution of marker ions, corticosteroids and antibiotics demonstrated that the concentration of substances applied to the RW was two to three orders of magnitude higher in the base compared to the apex. The measurements, however, involved perforating the cochlear bony wall and, in some cases, sampling perilymph. These manipulations can change the flow rate of perilymph and lead to intake of perilymph through the cochlear aqueduct, thereby disguising concentration gradients of the delivered substances. In this study, the suppressive effect of salicylate on cochlear amplification via block of the outer hair cell (OHC) somatic motility was utilized to assess salicylate diffusion along an intact guinea pig cochlea in vivo. Salicylate solution was applied to the RW and threshold elevation of auditory nerve responses was measured at different times and frequencies after application. Resultant concentrations of salicylate along the cochlea were calculated by fitting the experimental data using a mathematical model of the diffusion and clearing of salicylate in a tube of variable diameter combined with a model describing salicylate action on cochlear amplification. Concentrations reach a steady-state at different times for different cochlear locations and it takes longer to reach the steady-state at more apical locations. Even at the steady state, the predicted concentration at the apex negligible. Model predictions for the geometry of the longer human cochlea show even higher differences in the steady-state concentrations of the drugs between cochlear base and apex. Our findings confirm conclusions that achieving therapeutic drug concentrations throughout the entire cochlear duct is hardly possible when the drugs are applied to the RW and are distributed via passive diffusion. Assisted methods of drug delivery are needed to reach a more uniform distribution of drugs along the cochlea
Teaching of Faraday's and Lenz's theory of electromagnetic induction using java based Faraday's lab simulations
The effect of Faraday�s lab simulation software on perception of the students about Faraday�s and Lenz�s theory of electromagnetic induction (EMI) was studied. Students� perception about the topic before and after simulation was noted. Teaching with Faraday�s lab simulation creates the interest and curiosity about EMI phenomenon among students. It makes the study easy and reduces the real laboratory work. This simulation helps the students to learn the EMI phenomenon by their own.Se estudió el efecto de los programas de laboratorio de simulación Faraday en la percepción de los estudiantes acerca de la teoría de Faraday y de Lenz de la inducción electromagnética (EMI). Se señaló la percepción de los estudiantes sobre el tema antes y después de la simulación. Enseñar con simulaciones de laboratorio de Faraday crea el interés y la curiosidad sobre el fenómeno de EMI entre los estudiantes. Hace el estudio fácil y reduce el trabajo de laboratorio real. Esta simulación permite a los estudiantes aprender el fenómeno de la EMI por su cuenta propia
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