SSP Method Research Articles

Enhancement and refinement of SSP method for XRD analysis and investigation of structural properties of pure and Ca-doped zinc oxide

Enhancement and refinement of SSP method for XRD analysis and investigation of structural properties of pure and Ca-doped zinc oxide

Alloreactive memory B cell detection by flow cytometric cross match using polyclonally activated memory B cell culture supernatants

In addition to alloantibodies, alloreactive memory B cell (mBC) evaluation has a potential for immunological risk assessment during transplantation processes. For the alloreactive mBCs evaluation currently, direct Flow Cytometric (FC) analysis using the HLA tetramer staining is an option. Evaluation of alloantibodies produced by the polyclonally stimulated alloreactive mBCs in in vitro culture system seems to be another useful approach, but this needs further downstream applications. In this study, we investigated the usefulness of the Flow Cytometric Cross Match (FCXM-supernatant) in which in vitro polyclonally activated mBCs culture supernatants and potential donor's lymphocytes being used for the mBC detection. FCXM-supernatant assays were performed between culture supernatants of polyclonally activated mBCs obtained from 4 allosensitized multiparous women and 14 renal transplant patients, and their non-alloimmunized spouses' or donors' lymphocytes, and vice versa. HLA typing was performed by SSP method. Anti-HLA antibodies produced by in vitro activated alloreactive mBCs were also evaluated by the Luminex assays. The success of in vitro polyclonal activation of mBCs was evaluated by a total IgG ELISA test and antibody secreting cell analyses by FC. Donor specific alloreactive mBCs were detected by FCXM-supernatant in 45% of the 18 allosensitized cases. Detection rate was 85% (6 out of 7) in the strongly allosensitized cases. No alloreactive mBCs was detected in control cases without allosensitization. FCXM-supernatant negative results of the allosensitized cases were related to low level of allosensitization and insufficient polyclonal stimulation evaluated by total IgG antibody tests of the supernatants. We herein report a practical methodology for alloreactive mBC detection as a donor specific manner using the FCXM-supernatant assay so that this would easily be transformed into a routine test performed in tissue typing laboratories.

Platelet HPA Typing of Platelet Donors in Zhangjiakou Area

To analyze the polymorphism of the HPA1-5,15 system of the donors in Zhangjiakou area. DNA was extracted from the blood samples of the donors, PCR- SSP method was used to divide HPA1-6, 15 genotype. The gene frequency and genotype frequency were calculated, compared with the difference and regiahal specificity of the populations in our country and foregiens was compared other populations. The gene expression in the HPA-1, HPA-2 and HPA-4 systems were all homozygous aa, and the donors who expressed homozygous bb was not exessed. Among them, one heterozygous ab expression was found in both HPA-1 and HPA-4 systems (1%), and 14 cases of heterozygous ab expression were found in HPA-2 system (14%). The gene expression in the HPA-5 system was mainly homozygous aa (98%), and a very few expressed homozygous bb (2%) was found. The degree of heterozygosity of gene expression in the HPA-3 and HPA-15 systems was relatively high. The proprotion of the expression of aa, ab and bb in the HPA-3 system was respectively 46%, 40% and 14%, the proprotion of the expression of aa, ab and bb in the HPA-15 system was respectively 21%, 64% and 15%. The gene frequency of platelet-specific antigen HPA1-5,15 system in zhangjiakou region shows local characteristics. The heterozygosity degree of gene expression in the HPA-3 and HPA-15 systems are both high, suggesting that they are more likely to result in alloimmunization and ineffective platelet transfusion, which should be pays attention to.

Doping Effect and Microstructure Behavior of Rare-Earth Element Cerium (Ce+3) in Barium Hexaferrite (BaCexFe12-xO19) Nanoparticles

Cerium substituted BaM hexaferrites BaCexFe12-xO19 (x = 0.0, 0.25, 0.5, 0.75, and 1.0) nano crystallites were synthesized via Sol-gel method. The x-ray diffraction (XRD) patterns were analyzed by Rietveld refinement which confirms the formation of hexagonal structure. The crystalline size was calculated by Debye Scherrer method, W–H method and SSP method. The lattice constant ? found to decrease, this was due to the octahedral site replacing a large radius of Ce3+ ion with a smaller radius Fe3+ ion, While the lattice constant c found increase. The x-ray density observed increases with increasing Ce3+ concentration. Fourier transform infrared spectroscopy (FTIR) confirmed the two frequency bands n1 tetrahedral site and n2 octahedral site in a range between 400–620 cm-1. Impedance analyzer was used to investigate the dielectric properties in a range of 1 MHz – 3 GHz following Maxwell Wagner model. Dielectric constant showed decreasing trend while dielectric loss showed dispersive behavior by increasing frequency and same was that with tangent loss, such behavior was due to Koop's phenomenological theory. AC conductivity exhibits a plane behavior in a low frequency, while dispersive in high frequency. Such behavior was due to grain effect at high frequency. Impedance showed continuous action at high frequency, which is attributed to the release of space charges. The real and imaginary modulus showed variation by increasing frequency, which was due to the occurrence of relaxation phenomenon. As per dielectric research, these ferrites can be utilized in high frequency devices, microwave technologies, and semiconductor devices.

Comparing Methods for Calculating Nano Crystal Size of Natural Hydroxyapatite Using X-Ray Diffraction.

We report on a comparison of methods based on XRD patterns for calculating crystal size. In this case, XRD peaks were extracted from hydroxyapatite obtained from cow, pig, and chicken bones. Hydroxyapatite was synthesized through the thermal treatment of natural bones at 950 °C. XRD patterns were selected by adjustment of X-Pert software for each method and for calculating the size of the crystals. Methods consisted of Scherrer (three models), Monshi–Scherrer, three models of Williamson–Hall (namely the Uniform Deformation Model (UDM), the Uniform Stress Deformation Model (USDM), and the Uniform Deformation Energy Density Model (UDEDM)), Halder–Wanger (H-W), and the Size Strain Plot Method (SSP). These methods have been used and compared together. The sizes of crystallites obtained by the XRD patterns in each method for hydroxyapatite from cow, pig, and chicken were 1371, 457, and 196 nm in the Scherrer method when considering all of the available peaks together (straight line model). A new model (straight line passing the origin) gave 60, 60, and 53 nm, which shows much improvement. The average model gave 56, 58, and 52 nm, for each of the three approaches, respectively, for cow, pig, and chicken. The Monshi–Scherrer method gave 60, 60, and 57 nm. Values of 56, 62, and 65 nm were given by the UDM method. The values calculated by the USDM method were 60, 62, and 62 nm. The values of 62, 62, and 65 nm were given by the UDEDM method for cow, pig, and chicken, respectively. Furthermore, the crystal size value was 4 nm for all samples in the H-W method. Values were also calculated as 43, 62, and 57 nm in the SSP method for cow, pig, and chicken tandemly. According to the comparison of values in each method, the Scherrer method (straight line model) for considering all peaks led to unreasonable values. Nevertheless, other values were in the acceptable range, similar to the reported values in the literature. Experimental analyses, such as specific surface area by gas adsorption (Brunauer–Emmett–Teller (BET)) and Transmission Electron Microscopy (TEM), were utilized. In the final comparison, parameters of accuracy, ease of calculations, having a check point for the researcher, and difference between the obtained values and experimental analysis by BET and TEM were considered. The Monshi–Scherrer method provided ease of calculation and a decrease in errors by applying least squares to the linear plot. There is a check point for this line that the slope must not be far from one. Then, the intercept gives the most accurate crystal size. In this study, the setup of values for BET (56, 52, and 49 nm) was also similar to the Monshi–Scherrer method and the use of it in research studies of nanotechnology is advised.

A Correlated Source-Sink-Potential Model Consistent with the Meir-Wingreen Formula.

We model a molecular device as a molecule attached to a set of leads treated at the tight-binding level, with the central molecule described to any desired level of electronic structure theory. Within this model, in the absence of electron-phonon interactions, the Landauer-Büttiker part of the Meir-Wingreen formula is shown to be sufficient to describe the transmission factor of the correlated device. The key to this demonstration is to ensure that the correlation self-energy has the same functional form as the exact correlation self-energy. This form implies that nonsymmetric contributions to the Meir-Wingreen formula vanish, and hence, conservation of current is achieved without the need for Green's Function self-consistency. An extension of the Source-Sink-Potential (SSP) approach gives a computational route to the calculation and interpretation of electron transmission in correlated systems. In this picture, current passes through internal molecular channels via resonance states with complex-valued energies. Each resonance state arises from one of the states in the Lehmann expansion of the one-electron Green's function, hole conduction derived from ionized states, and particle conduction from attached states. In the correlated device, the dependence of transmission on electron energy is determined by four structural polynomials, as it was in the tight-binding (Hückel) version of the SSP method. Hence, there are active and inert conduction channels (in the correlated case, linked to Dyson orbitals) governed by a set of selection rules that map smoothly onto the simplest picture.

Kernel Based High Order “Explicit” Unconditionally Stable Scheme for Nonlinear Degenerate Advection-Diffusion Equations

In this paper, we present a novel numerical scheme for solving a class of nonlinear degenerate parabolic equations with non-smooth solutions. The proposed method relies on a special kernel based formulation of the solutions found in our early work on the method of lines transpose and successive convolution. In such a framework, a high order weighted essentially non-oscillatory methodology and a nonlinear filter are further employed to avoid spurious oscillations. High order accuracy in time is realized by using the high order explicit strong-stability-preserving (SSP) Runge-Kutta method. Moreover, theoretical investigations of the kernel based formulation combined with an explicit SSP method indicate that the combined scheme is unconditionally stable and up to third order accuracy. Evaluation of the kernel based approach is done with a fast $${\mathcal {O}}(N)$$ summation algorithm. The new method allows for much larger time step evolution compared with other explicit schemes with the same order accuracy, leading to remarkable computational savings.

Synthesis, morphology, crystallite size and adsorption properties of nanostructured Mg–Zn ferrites with enhanced porous structure

Mg–Zn ferrites with porous cavity structure were produced by sol-gel auto-combustion method utilizing a new mixture of dl-alanine and urea as an organic fuel-reductant. The influence of non-magnetic Zn ions content on the structural, morphological and adsorption characteristics of Mg–Zn NPs has been investigated. It was found that Zn effects the porosity of Mg–Zn ferrospinels. X-ray diffraction analysis confirmed the formation of cubic spinel phase and the crystallite size was calculated by the SSP method, W-H method and modified Scherrer formula. SEM observations revealed mesh-like microstructure with the presence of 1–2 μm macropores and agglomerated nanoparticles. The EDS spectra confirmed the desired chemical composition of ferrites powders. Mössbauer spectroscopy confirmed the valence state of cations and their distribution over the spinel sublattices. The adsorption characteristics of spinel compounds were studied on Congo Red dye removal. The appropriateness of Langmuir, Freundlich, and Dubinin-Radushkevich adsorption models were investigated and the parameters of all models were determined. The observed data fitted well by Langmuir model, indicating that the Congo Red adsorption occurred on a homogeneous surface and that the active surface centers possessed similar energy values. The Dubinin-Radushkevich isotherm model was utilized to calculate the free energy of Congo Red adsorption, i.e. setting in the range 7.81–22.4 kJ/mol and indicating that the Zn content affects the mechanism of Congo Red adsorption onto ferrite surfaces and the removal efficiency is enhanced with the rise in Zn content.

An Investigation on the Supercapacitive Performance of CuCo2O4/Polyaniline, a Nanocomposite of Spinel Structured Transition Binary Metal Oxide and Conducting Polymer, with a Special Focus on Bonding and Electron Density Distribution Through MEM

CuCo2O4 nanomaterial was synthesized by cost effective, time saving combustion route and a composite material CuCo2O4/PANI was prepared by physical blending. X-ray diffractometer studies were used to characterize the structural properties of synthesized nanoparticles thereby confirming the appearance of cubic spinel phase with the crystallite size ranging from 10 to 40 nm. Rietveld refinement method was used to derive density of nanoparticles, unit cell volume and other parameters. Fourier transform infrared spectroscopy was used to confirm the functional groups as well as the presence of vibrations in the samples which is in accordance with XRD results. The distribution of electron density and chemical bonding were studied through maximum entropy method. The changes in these factors in pure and composite have demonstrated improved electrochemical behavior of the latter. The crystallite size and lattice strain were calculated by Williamson–Hall (W–H) analysis, and size-strain plot method (SSP) that was in correlation with that of Scherrer method. Findings from SSP method, Scherrer and HR-TEM results were well matched. The morphology of synthesized nanoparticles of pure and composite were examined through FE-SEM and HR-TEM images. The morphological changes have proved improved electrochemical capability of the composite. The morphological observations of FE-SEM and HRTEM were in good accordance. The crystalline property of the materials is confirmed from SAED patterns of HRTEM that matched well with the XRD study. The electrochemical characterization of the samples was carried out by CV and CP observations. The composite material CuCo2O4/PANI exhibited a higher maximum specific capacitance of 659 F/g at 5 mV/s scan rate in comparison with 515 F/g exhibited by pure CuCo2O4 as calculated from CV. The higher performance of the composite material is also evident by the electrochemical impedance study, as the resistance was lower than the pure. The ESR of the composite was 3.52 V and that of pure was 5.93 V, as obtained from the Nyquist plot. On the basis of outcome of the results, CuCo2O4/PANI nanocomposite displays better performance when compared to the pure CuCo2O4. This has been achieved by low cost, time saving and simple synthesis method.

Effect of silver dopant on structural and optical properties of ZnO nanoparticles

The synthesis of AgxZn1−xO is completed by chemical precipitation method and then X-ray diffraction is used to detail out the structural parameters (like crystallite size and phase identification). A hexagonal wurtzite structure is confirmed after analyzing the XRD results, which shows a single phase. The crystallite size and microstrain are evaluated by different models of W–H and SSP method; their values show an increasing pattern with the rise in the doping element. While band gap value decreases with rise in the concentration ratio of silver doping, in contrast to this Urbach energy (eV) is opposite to the band gap value that is evaluated by the absorption spectra of UV–Vis. This is mostly used in the optoelectronic application. The FTIR (Fourier transmission infrared spectroscopy) results are detailed about functional bonds; Ag bonds appear in its representation within ZnO bond. FESEM confirmed that the aggregation formation increases with increases in silver doping concentrations.

Donor KIR3DL1/Receptor HLA-Bw4-80I Combination Reduce Acute Leukemia Relapse after Umbilical Cord Blood Transplantation without in Vitro T-Cell Depletion

Objective: How to reduce relapse is still a puzzle in the treatment of acute leukemia patients with allogeneic umbilical cord blood hematopoietic cell transplantation (UCBT). Donor natural killer (NK) cell alloreactivity in UCBT can control leukemic relapse, However, NK cell function is calibrated through education, that is governed by human leukocyte antigens (HLAs), our study aim to investigate the Graft-resistant leukemia effect after transplantation of KIR3DL1 and its different ligand HLA-B subtypes(BW6, Bw4-80T, Bw4-80I).Design and method: we retrospectivly analysed single center of 232 acute leukemia patients who underwent UCBT(myeloablative conditioning without ATG). The killer immunoglobulin-like receptor (KIR) genotype of cord blood donors was detected by SSP method, they all contains KIR3DL1. There were 104 cases of acute lymphoblastic leukemia, 112 cases of acute myeloid leukemia, 16 cases of myelodysplastic syndrome. 168 cases of transplant patients in remission period, and 64 cases of non-remission. There were 122 males and 110 females with a median age of 13 years (2-45 years). The patients were divided into three groups according to HLA-B locus, 1.patients had BW6 in both two HLA-B locus(group 1, N=86) , which means uneducated; 2.patients had HLA-Bw4-80T in the HLA-B locus(group 2, N=68), which means educated; 3.patients had HLA- Bw4-80I in the HLA-B locus(group 3, N=77), which means highly educated. The receptors were followed-up from July 31, 2012 to December 30,2017, in graft failure, neutrophil engraftment, platelet engraftment, acute graft-versus-host disease (aGVHD), chronic graft-versus-host disease (cGVHD), relapse, overall survival (OS), and leukemia free survival (LFS).Results: In group 3 patients, donor KIR3DL1 and receptor HLA-Bw4-80I combinations that were predictive of highly educated were associated with significantly lower relapse (hazard ratio [HR], HR = 0.49; P =0 .004) and better LFS (HR = 0.68, p = 0.014), compared with the educated(group2) and uneducated (group3) group, with no significant increase in aGVHD and cGVHD incidence. While no difference was observed in the other index in the three group.Conclusion : Alloreactivity of NK cells demonstrated reproducible patterns of strong or weak graft-versus-leukemia (GVL) effect against leukemia blast, which is depend on donor KIR3DL1/receptor HLA-B subtype combinations. Our data suggests that donor KIR3DL1/receptor HLA-Bw4-80I combination in UCBT may achieve superior graft versus leukemia effects, lower risk for relapse among patients with acute leukemia.Keywords: KIR, Umbilical Cord Blood Transplantation, UCBT, GVL DisclosuresNo relevant conflicts of interest to declare.

X-ray Diffraction Line Profile Analysis of Undoped and Se-Doped SnS Thin Films Using Scherrer’s, Williamson–Hall and Size–Strain Plot Methods

An electrochemical route has been employed to prepare undoped and Se-doped SnS thin films. Six samples including undoped and Se-doped SnS thin films were deposited on the fluorine-doped tin oxide glass substrate. An aqueous solution containing 2 mM SnCl2 and 16 mM Na2S2O3 was used in the electrolyte. Different Se-doped SnS samples were prepared by adding the various amounts of 4 mM SeO2 solution into the electrolyte. The applied potential (E), time of deposition process (t), pH, and bath temperature (T) were kept at − 1 V, 30 min, 2.1, and 60°C, respectively. After the completion of the deposition process, x-ray diffraction (XRD) and transmission electron microscopy (TEM) were utilized to characterize the deposited thin films. XRD patterns clearly showed that the synthesized undoped and Se-doped SnS thin films were crystallized in the orthorhombic structure. Using Scherrer’s method, the crystallite size of deposited thin films is calculated. In addition, the crystallite size and lattice strain have been estimated using the modified form of the Williamson–Hall (W–H) method containing a uniform deformation model, a uniform deformation stress model, a uniform deformation energy density model, and by the size–strain plot method (SSP). The shape of SnS crystals was spherical in TEM images. The results showed that there was a good agreement in the particle size obtained from the W–H method and the SSP method with TEM images.

X-ray peak profile analysis of CoAl2O4 nanoparticles by Williamson-Hall and size-strain plot methods

CoAl2O4nanoparticles were prepared by a sol-gel process using citric acid as chelating agent with different calcination temperatures of 600 to 900 °C. The crystalline spinel cubic phase was confirmed by X-ray diffraction results. High-resolution scanning electron microscopy (HRSEM) revealed that nanoparticles of CoAl2O4morphology showed spherical forms with a certain degree of agglomeration. The Williamson-Hall (W-H) method and size-strain method to evaluate the size of crystallites and strain in the CoAl2O4nanoparticles peak broadening were applied. Physical parameters such as strain and stress values were calculated for all XRD reflection peaks corresponding to the cubic spinel phase of CoAl2O4in the range of 20 to 70° from the modified plot shape by W-H plot assuming a uniform deformation model (UDM), uniform stress deformation model (USDM), uniform deformation energy density model (UDEDM) and by the size-strain plot method (SSP). The CoAl2O4NPs crystal size calculated on the W-H plots and the SSP method are in good agreement with the HRSEM Scherrer method.

Assessment of different coarse graining strategies to simulate polydisperse gas-solids flow

Continuum methods require the additional development of solids stress closures for polydisperse powders based on complex kinetic theories that are non-trivial to develop, code, and numerically converge for the wide range of fluidization regimes from very dilute to dense/frictional flow limit. On the other hand, it is straightforward to model the flow of polydisperse granular materials by treating particles as discrete rigid bodies that are tracked following simple physical laws of motion. The coarsening of these discrete methods by lumping several particles in a parcel alleviates the significant computational cost associated with these discrete methods while introducing some inaccuracies in the numerical results. In this research, we explore two different coarse graining methods that can be applied to polydisperse powders, namely the same statistic weight method (SSW) and the same size parcel method (SSP), and assess their accuracy by comparison with the finest simulation results obtained with a discrete element method (DEM). For Geldart group B powders fluidized at a relative low superficial velocity, the numerical results indicate that the SSW is more accurate than the SSP method. For type A powders fluidized at relatively high velocity, these two methods predict similar results. Interestingly, up to four times increase in the speed of simulation of the SSP method was obtained because the original polydisperse powder is scaled to a mono-disperse system in terms of particle-particle collision. These results suggest that the SSP method is more favorable for the simulation of fluidized beds due to its accuracy and efficiency while the SSW method may be used for granular flow and dense fluidized bed systems where capturing the size segregation of particles due to collision is important.

$$L_2$$ L 2 Stability of Explicit Runge–Kutta Schemes

Explicit Runge–Kutta methods are standard tools in the numerical solution of ordinary differential equations (ODEs). Applying the method of lines to partial differential equations, spatial semidiscretisations result in large systems of ODEs that are solved subsequently. However, stability investigations of high-order methods for transport equations are often conducted only in the semidiscrete setting. Here, strong-stability of semidiscretisations for linear transport equations, resulting in ODEs with semibounded operators, are investigated. For the first time, it is proved that the fourth-order, ten-stage SSP method of Ketcheson (SIAM J Sci Comput 30(4):2113–2136, 2008) is strongly stable for general semibounded operators. Additionally, insights into fourth-order methods with fewer stages are presented.

The association of HLA B*15:02 allele and Stevens–Johnson syndrome/toxic epidermal necrolysis induced by aromatic anticonvulsant drugs in a South Indian population

The presence of HLA-B*15:02 allele is considered a risk factor for development of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in patients taking aromatic anticonvulsant drugs like carbamazepine and phenytoin. The genetic association is ethnicity specific. Testing for HLA-B*15:02 allele is suggested as a prerequisite before starting carbamazepine in certain ethnic groups. There are only a few/no studies from south India on HLA association of SJS/TEN. To identify any association between HLA-B*15:02 allele and SJS/TEN induced by carbamazepine/phenytoin among native population. METHODS (INCLUDING SETTINGS, DESIGN, AND STATISTICAL ANALYSIS USED): A case-control study done in a tertiary care center at Kottayam in Kerala state of south India. Cases were 12 native patients who developed SJS/TEN owing to aromatic anticonvulsant drugs (phenytoin - 8; carbamazepine - 4), and controls were 11 persons tolerant to these drugs from unrelated families of the same ethnic group. HLA-B typing was done by PCR SSP method. There was only one HLA-B*15:02 carrier among cases and controls. He/she had SJS/TEN induced by carbamazepine. Association of HLA-B*15:02 with phenytoin-induced SJS/TEN is rare in the population studied. The one limitation of the study was the small sample size.

P138 KIR Genotypes that encode activating NK cell receptor repertoire are associated with the sever form of rheumatic heart disease among south Indian population

Aim Rheumatic heart disease (RHD) is an inflammatory autoimmune disease, occurring as a sequel of exaggerated host immune response to cross reactive group A streptococcal infection in an susceptible host. Natural killer (NK) cells play a crucial role in modulating innate and adaptive immune responses against infection. Since polymorphic killer cell Ig-like receptors (KIR) regulate NK cell response, we investigate if any KIR genes are associated with RHD. Methods Blood samples were collected from 90 RHD patients enrolled in Govt. Rajaji Hospital, Madurai, India, along with their 117 healthy siblings with their consent. Based on echocardiography data, patients were further classified as those with mitral valvular lesions (MVL) (N = 63) or with combined valvular lesions (CVL) (N = 22). Five patients had only rheumatic fever without valvular damage. Genomic DNA was extracted and KIR genes were typed by duplex SSP method. Unusual KIR genotypes were further confirmed by One Lambda rSSO method. Comparisons were made by two-tailed Fisher’s exact probabilities (p), with p Results No difference was observed in the frequencies of any KIR genes between RHD and sibling controls (see Fig). Compared to siblings, a slight decrease was observed in the frequencies of 3DL1 and 2DS4 in RHD patients, and the decrease was statistically significant in CVL subset. Moreover, 80% of CVL patients carried 4 activating KIRs (2DS5, 2DS1, 3DS1, 2DS2), while only 51% of siblings 41% of MVL group carried these activating KIRs. Conclusions A decreased frequency of inhibitory 3DL1 and increased frequency of 4 activating KIRs in CVL group suggest that a dominant activating KIR repertoire may involve in the pathogenesis of CVL phenotype. Further analyses with more CVL patients as well as typing of HLA ligands and 3DL1 and 2DS4 subtypes are necessary to substantiate this clinically relevant genetic association. Download : Download high-res image (409KB) Download : Download full-size image

P181 KIR2DL3 protects the development of type 1 diabetes in children under 10 years old in South Indian population

Aim Type 1 diabetes (T1D) is a multifactorial autoimmune disease that leads to the destruction of insulin producing β -cells of pancreas. Natural killer (NK) cells not only exert cytotoxic activity against tumor cells or infected cells but also act to regulate the function of other immune cells through cell contact-dependent mechanisms or secretion of cytokines and chemokines. Killer cell Ig-liker receptors (KIR) are key receptors of human NK cells. The aim of the present study is to identify if any association between KIR genes T1D. Methods Blood samples were collected from T1D patients (n = 112) with varied age of onset (0–10 yrs, n = 30; 10–20 yrs, n = 56; >20 years, n = 26) enrolled in Govt. Rajaji Hospital, Madurai, India along with their healthy siblings (n = 51) with due ethical clearance and consent. Genomic DNA was extracted and KIR genes were typed by duplex SSP method. Unusual KIR genotypes were further confirmed by One Lambda rSSO method. Comparisons were made by two-tailed Fisher’s exact probabilities (p), with p Results No difference was observed in the frequencies of any KIR genes between T1D and sibling controls (see figure). However, a significant decrease in the frequency of KIR2DL3 was observed in early onset patients of 0–10 years old compared to sibling controls (66.7% vs. 86.3%; P Conclusions The KIR2DL3 seems to be protective from developing T1D in young children. The protective NK cell activity may be mediated through weak inhibitory KIR2DL3 interactions (i.e., the lack of strong NK cell inhibition), perhaps in combination with one of the many conserved NK cell activating receptors. Further analyses of HLA ligands are necessary to substantiate this novel genetic association. Download high-res image (418KB) Download full-size image

Estimation of Lattice Stress and Strain in Zinc and Manganese Ferrite Nanoparticles by Williamson–Hall and Size-Strain Plot Methods

The Williamson–Hall (W–H) analysis and size-strain plot method (SSP) were used to study the lattice stress, strain and crystalline size of zinc (ZnFe2O4) and manganese (MnFe2O4) ferrite nanoparticles. These nanoparticles were synthesized by chemical co-precipitation method and characterized by powder X-ray diffraction analysis (PXRD). The PXRD results revealed that the sample product was crystalline with mixed type spinel with cubic structure. The crystalline development in the ZnFe2O4 and MnFe2O4 was investigated by X-ray peak broadening. The physical parameters such as strain, stress and energy density values were calculated more precisely for all the reflection peaks of PXRD using the W–H plots and SSP method. The variation in particle size, lattice strain, stress and energy density calculated from W–H analysis and SSP method reveals a nonuniform strain in the particles. This nonuniform strain was increased when the particle sizes were increased.

OR6 The positive virtual crossmatch. Correlation between HLA DSA and flow cytometry crossmatch results

Aim Virtual crossmatch (VXM) is a good tool to expedite and streamline pre-transplant recipient selection and facilitate national organ sharing. However, VXM can be a barrier to transplantation, based on donor specific antibodies (DSA) detected by single antigen bead (SAB) testing, especially when low MFI cutoffs are used to assign unacceptable antigens. Recent studies report good clinical outcomes in patients transplanted across DSA with a negative FCXM, emphasizing that the choice of VXM cutoffs should be based on careful correlation with FCXM. The purpose of this study was to assess the correlation between MFI of DSA and FCXM results. Methods The results of 2843 deceased donor FCXM performed at our center between 03/2015 and 03/2016 were analyzed and correlated with cumulative MFI of locus specific DSA. Donors were typed (HLA-A, B, C, DR, DQ) by SSP method. FCXM were performed as per Halifax protocol (Liwski et al., ASHI Q 2015) with spleen or lymph node derived donor cells. SAB testing (LABScreen) was performed with heat inactivated sera to prevent prozone. DSA were assigned based on 1000 (1K) MFI cutoff. All sera with DP antibodies were excluded. Results Of 1859 VXM −ve samples (no DSA), 56 were FCXM +ve (3% false positive rate). Of 318 VXM +ve (DSA; >1K MFI) samples, only 214 (67.3%) were FCXM +ve. The degree of concordance, VXM vs FCXM, was locus and MFI dependent (Fig. 1). HLA-A and B DSA predicted a +ve FCXM (T and/or B) in 80%, 93% and 100% of cases using 1K, 2K and 5K cutoffs respectively. HLA-DR DSA predicted positive B cell FCXM in 54%, 89% and 100% of cases with same MFI cutoffs. HLA-C and DQ DSA predicted positive FCXM reliably only when 10K cutoff was used (100% and 95% respectively; Fig. 1). Conclusions Concordance between VXM and FCXM depends on MFI cutoff and DSA locus. 1K cutoff is not useful for FCXM prediction regardless of DSA specificity. For HLA-A, B and DR DSA, 2–5K cutoff can be used to reliably predict FCXM, while for HLA-C and DQ only 10K cutoff is predictive. Download : Download high-res image (138KB) Download : Download full-size image