► Ni–Cd ferrite nanoparticles synthesized by citrate gel process. ► Cation distribution of Ni–Cd ferrite nanoparticles. ► IR and XRD spectra reveals the formation of single phase cubic spinel ...structure. ► Magnetization shows the Cd2+ ion dependency.
Ultrafine Ni1−xCdxFe2O4 (where x=0.0–0.5 in steps of 0.1) ferrite nanoparticles have been synthesized by the citrate gel process. The X-ray analysis confirmed the single phase cubic spinel structure of the synthesized powder. The lattice constant is found to increase with the increase in concentration of cadmium. The energy dispersive analysis of X-ray (EDAX) shows that the theoretical and observed percentage of the elements; Ni2+, Cd2+ and Fe3+ and they are in the desired stoichiometric proportion. The distribution of metal ions in the spinel ferrite system is determined from the X-ray diffraction studies. The Fourier Transform Infrared Spectra (FT-IR) of the Ni–Cd ferrite system have been analysed in the frequency range of 350–800cm−1. FT-IR spectra revealed the two prominent frequency bands, one is high frequency band ν1 and another is law frequency band ν2 which are assigned to the tetrahedral and octahedral metal complexes respectively. Saturation magnetization decreased with the Cd2+ substitution. Resistivity of the samples was measured using the two probe technique. AC susceptibility was used to determine the Curie temperature of the samples.
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► Cr3+ substituted Ni–Zn ferrite. ► Crystallite size decreases with increasing Cr3+. ► Magnetization decreases whereas coercivity increases with increasing Cr3+. ► Permeability ...decreases with increasing Cr3+.
A series of ferrite samples with the chemical formula Ni0.7Zn0.3CrxFe2−xO4 (x=0.0–0.5) were prepared by a sol–gel auto-combustion method and annealed at 600°C for 4h. The resultant powders were investigated by various techniques, including X-ray diffractometry (XRD), vibrating sample magnetometry (VSM), and permeability studies. The prepared samples have a cubic spinel structure with no impurity phase. As the Cr3+ content x increases, bulk density and crystallite size decrease, whereas porosity increases. The saturation magnetization decreases linearly from 58.31 to 42.90emu/g with increasing Cr3+ content. However, coercivity increases with increasing Cr3+ substitution. The magnetic moments calculated from Neel's molecular-field model are in agreement in the experiment results. The initial permeability (μi) decreases with increasing Cr3+ substitution. The decrease in initial permeability (μi) is attributed to decrease in magnetization on addition of Cr3+. The real part of the permeability decreases gradually with increasing frequency in accordance with Snoek's law. The Curie temperature decreases linearly with increasing Cr3+ content.
To investigate the role of small intestinal carcinoid tumor-derived fibrotic mediators, TGFbeta1 and CTGF, in the mediation of fibrosis via activation of an "intestinal" stellate cell.
GI carcinoid ...tumors were collected for Q RT-PCR analysis of CTGF and TGFbeta1. Markers of stellate cell desmoplasia were identified in peritoneal fibrosis by immunohistochemistry and stellate cells cultured from fresh resected fibrotic tissue. CTGF and TGFbeta1 were evaluated using quantitative tissue array profiling (AQUA analysis) in a GI carcinoid tissue microarray (TMA) with immunostaining and correlated with clinical and histologically documented fibrosis. Serum CTGF was analyzed using a sandwich ELISA assay.
Message levels of both CTGF and TGFbeta1 in SI carcinoid tumors were significantly increased (> 2-fold, P < 0.05) versus normal mucosa and gastric (non-fibrotic) carcinoids. Activated stellate cells and markers of stellate cell-mediated fibrosis (vimentin, desmin) were identified in histological fibrosis. An intestinal stellate cell was immunocytochemically and biochemically characterized and its TGFbeta1 (10-7M) initiated CTGF transcription response (> 3-fold, P < 0.05) demonstrated. In SI carcinoid tumor patients with documented fibrosis, TMA analysis demonstrated higher CTGF immunostaining (AQUA Score: 92 +/- 8; P < 0.05), as well as elevated TGFbeta1 (90.6 +/- 4.4, P < 0.05). Plasma CTGF (normal 12.5 +/- 2.6 ng/mL) was increased in SI carcinoid tumor patients (31 +/- 10 ng/mL, P < 0.05) compared to non-fibrotic GI carcinoids (< 15 ng/mL).
SI carcinoid tumor fibrosis is a CTGF/TGFbeta1-mediated stellate cell-driven fibrotic response. The delineation of the biology of fibrosis will facilitate diagnosis and enable development of agents to obviate its local and systemic complications.
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Nodule-type polyaniline (PAni) has been successfully electrosynthesized onto conducting substrate and envisaged in electrochemical supercapacitor (ES) application as a potential ...energy storage electrode. Various bands are confirmed from the X-ray photoelectron and Fourier transform infrared spectra. Each nodule is of ∼100–200nminlength and 20–80nmindiameter. The ∼45° surface water contact angle with water of PAni surface can be beneficial for accessing an entire electrode area with minimum interfacial resistance loss when is in contact with the aqueous electrolyte for ES application. The PAni nodule-type electrode when electrochemically characterized using cyclic-voltammetry and galvanostatic charge–discharge measurements has demonstrated a specific capacitance of ∼508Fg−1, a specific energy of 32.12Whkg−1, a specific power of 13.39kWkg−1 and a Coulombic efficiency of 100% in 1MH2SO4 electrolyte solution. An occurrence of 70% retention of initial capacity even after 5000 cycles is supporting for energy-storage application. Two separate redox reaction behaviors are confirmed in the discharge measurement.
Although there is emerging evidence to suggest equivalent oncological outcomes using a watch and wait approach compared with primary total mesorectal excision surgery, there is a paucity of evidence ...about the safety and efficacy of this approach in routine clinical practice. Here we report the long-term outcomes and quality of life from patients managed with watch and wait following a clinical complete response (cCR) to neoadjuvant therapy.
Patients with adenocarcinoma of the rectum with cCR following neoadjuvant therapy managed using watch and wait were retrospectively identified. Demographic data, performance status, pretreatment staging information, oncological and surgical outcomes were obtained from routinely collected clinical data. Quality of life was measured by trained clinicians during telephone interviews.
Over a 7-year period, 506 patients were treated for rectal cancer, 276 had neoadjuvant therapy and 72 had a cCR (26.1%). Sixty-three were managed with watch and wait. Thirteen patients had mucosal regrowth. There was no significant difference in the incidence of metastatic disease between the surgical and watch and wait cohorts (P = 0.38). The 13 patients with mucosal regrowth underwent salvage surgery. Eleven of the patients who underwent surgical resection had R0 resections. There was also a statistically and clinically significant improvement in the Functional Assessment of Cancer Therapy – Colorectal (FACT-C) trial outcome index (P = 0.022).
This study shows that watch and wait is safe and effective outside of tertiary referral centres. It suggests that an opportunistic cCR is durable and when mucosal regrowth occurs it can be salvaged. Finally, we have shown that quality of life is probably improved if a watch and wait approach is adopted.
•This study reports high clinical complete response rate (cCR) (26.1%).•It reports high pathological complete response rate (77.8%) following cCR.•All patients with mucosal regrowth underwent salvage surgery with R0 resection rate of 84.6%.•There was no difference in APER rate compared to the primary surgical cohort.•It demonstrates equivalent survival and improved sphincter preservation with watch-and-wait (WW).•This study is one of the first comparative reports of quality-of-life following WW and surgery.•It shows that colorectal specific quality-of life (p = 0.0008) and FACT-C TOI (p = 0.022) is better with WW.
A manganese oxide (MnO
2
) nanoplate-type electrode has been prepared using galvanostatic electrodeposition method with an aqueous manganese sulfate solution and characterized for its structural, ...morphological, compositional, and surface wettability studies and afterward envisaged in pseudocapacitor applications. The MnO
2
, evidenced through Raman and X-ray photoelectron spectroscopy analysis, electrode composed of nanoplate-type surface morphology is hydrophilic and amorphous in nature. The electrochemical properties of MnO
2
are examined using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy measurements in Na
2
SO
4
, NaOH, and KOH electrolytes, which demonstrate the pseudocapacitive signature with higher performance in Na
2
SO
4
electrolyte than the others. A maximum specific capacitance of 804 F g
−1
at a scan rate of 5 mV s
−1
within −0.3–1.0 V potential range, with 84% retention after 1000 cycles, in 1 M Na
2
SO
4
is evidenced.
Microchannel plates (MCPs) have been used for many years in space flight instrumentation as fast, lightweight electron multipliers. A new MCP fabrication method combines a glass substrate composed of ...hollow glass capillary arrays with thin film coatings to provide the resistive and secondary electron emissive properties. Using this technique, the gain, resistance, and glass properties may be chosen independently. Large‐area MCPs are available at moderate cost. Secondary emission films of Al2O3 and MgO provide sustained high gain as charge is extracted from the MCP. Long lifetimes are possible, and a total extracted charge of 7 C/cm2 has been demonstrated. Background rates are low because the glass substrate has little radioactive potassium 40. Curved MCPs are easily fabricated with this technique to suit instrument symmetries, simplifying secondary electron steering and smoothing azimuthal efficiency.
Key Points
MCPs can be made using glass substrates and ALD films
The resistance, gain, and substrate are independently selectable with ALD MCPs
ALD MCPs are easily made in curved, nonplanar formats
Research on the combination of low and high-bandgap energy materials through an ion-mediated chemical transformation of the nanostructure of one material into another, especially metal chalcogenide ...quantum dot (QD) solar cells plays a very important role in the fast charge transformation process with high power conversion efficiencies (PCE) by reducing surface charge recombinations. Based on a coordination chemistry approach, the present study demonstrates the importance of cation-exchange process in developing bandgap engineering of tin oxide–cadmium selenide (SnO2–CdSe) with zinc selenide (ZnSe) and tin selenide (SnSe) to form SnO2–CdSe/ZnSe and SnO2–CdSe/SnSe electrodes, respectively. Experimental conditions are optimized from optical and photovoltaic performances. Our best performing cation-exchange interface-modified photoelectrochemical devices, i.e., SnO2–CdSe/ZnSe and SnO2–CdSe/SnSe have achieved improvements of 21% and 28%, respectively, in their PEC values, i.e., 3.78% and 4.41% with remarkable current densities of 19.82 and 28.40 mA cm−2 when compared with SnO2–CdSe (1.63% and 9.74 mA cm−2). This is due to (a) the fast transfer of photo-generated electrons from the CdSe QD sensitizer to SnO2 photoanode by engineering a synergistically favourable band gap and (b) mitigation of a reverse photogenerated electron flow in the presence of a high band gap buffer ZnSe/SnSe layer, which would otherwise cause excessive recombinations. A simple cation-exchange interface modification process can, in general, pave the way for improving the performance of QD-based solar cells.
► Synthesis of ferrite by solution combustion route. ► Characterization techniques XRD, SEM, magnetization. ► Structural properties. ► Cation distribution. ► Magnetic properties.
The reactivity of ...Cu2+ ion concentration in Ni–Zn spinel matrix fabricated using solution combustion route has been investigated. The specimens of nanocrystalline Ni0.8−xCuxZn0.2Fe2O4 (x=0.0⩽0.6 with steps of 0.2) exhibits single phase cubic structure. The detailed studies regarding the physico-chemical stability, crystal structural stability, surface morphology and magnetic properties as a function of Cu2+ ion concentration were performed. The annealing treatment does not alter the crystal structure but increases the crystallinity of the samples. The cation occupancies of the prepared materials were estimated by using X-ray diffraction (XRD) data analysis. The morphological investigations of the samples were studied by using field emission scanning electron microscopy (FE-SEM) technique. The crystallographic analyses of all the compositions were systematically investigated by Fourier transform infrared spectroscopy (FTIR). The saturation magnetization (M–H plots) at room temperature with field 10kOe exhibits strong influence of Cu2+ ion content and annealing temperature.
Age-related macular degeneration (AMD) is a major cause of blindness in the elderly. We report a genome-wide screen of 96 cases and 50 controls for polymorphisms associated with AMD. Among 116,204 ...single-nucleotide polymorphisms genotyped, an intronic and common variant in the complement factor H gene (CFH) is strongly associated with AMD (nominal P value <10⁻⁷). In individuals homozygous for the risk allele, the likelihood of AMD is increased by a factor of 7.4 (95% confidence interval 2.9 to 19). Resequencing revealed a polymorphism in linkage disequilibrium with the risk allele representing a tyrosine-histidine change at amino acid 402. This polymorphism is in a region of CFH that binds heparin and C-reactive protein. The CFH gene is located on chromosome 1 in a region repeatedly linked to AMD in family-based studies.
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