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VM
Kinds of VM Terms modified by VM Selected AbstractsVirtual microscopy: An educator's tool for the enhancement of cytotechnology students' locator skillsDIAGNOSTIC CYTOPATHOLOGY, Issue 6 2008Jimmie Stewart III M.D. Abstract Virtual microscopy (VM) is being utilized as an educational tool in many areas of pathology. The aim of this study is to analyze the locator and diagnostic skills of cytotechnology students by using the Aperio T3 ScanScope®, and examine VM's viability as an educational tool in cytotechnology. Ten validated cytology slides were digitized and reviewed by three senior cytotechnologist instructors. Each technologist made annotations indicating diagnostic areas on the virtual slide. A subset of the slides was used for locator skill evaluation. Cytotechnology students examined a pristine copy of the virtual slide and made annotations for comparison to those made by experienced instructors. Annotations of the subset were then scored based on the degree of correlation between students and cytotechnologists. A cytopathologist performed a final review of the students' marks; points were then added or subtracted based on this interpretation. Students were graded based on their correlation to senior cytotechnologists. A statistical analysis using modified interrater calculations ranked the students as to locator ability, producing illuminating results. This study shows that VM has promise as a cytotechnology educational tool by allowing the instructor to evaluate students' locator and diagnostic abilities. We have attempted to implement a simple scoring system for evaluation of locator skills where students are compared versus expert cytotechnologists. We anticipate further technological improvements as the products mature. Diagn. Cytopathol. 2008;36:363,368. © 2008 Wiley-Liss, Inc. [source] A simple mounting model for consistent determination of the accuracy and repeatability of apex locatorsINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2006A. ElAyouti Abstract Aim, To develop a precise and simple mounting model (MM) for evaluating apex locators and to compare the repeatability of the MM with a conventional visual method (VM). Methodology, Electronic working length determination was performed in 32 maxillary central incisors using two methods: (i) the MM method and (ii) a conventional VM. The MM utilizes a micrometer to determine the distance travelled by the measuring file during working length determination. In the VM, the length of the measuring file (representing the working length) is determined visually using a caliper and a microscope at 6× magnification. Each measurement was repeated once. The repeatability of each method was evaluated by calculating the coefficient of repeatability. Results, The coefficient of repeatability, which includes 95% of the differences between repeated measurements, was 0.04 mm for MM compared with 0.9 mm for VM. The measurement error of MM was significantly lower than VM (0.02 and 0.4 mm respectively). There was a statistically significant difference between the means of absolute difference in repeated measurements: MM 0.01 mm (95% confidence interval (CI): 0.01; 0.02 mm) compared with VM 0.4 mm (95% CI: 0.3; 0.5 mm). Conclusion, The new MM had superior repeatability in comparison with the conventional method where visual interpretation is a source of inaccurate measurement. [source] A new approach for using the pathological mirror elements in the ideal representation of active devicesINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 2 2010Ramy A. Saad Abstract This paper is adopting a new approach to investigate the capabilities of pathological mirror elements in the ideal representation of active building-blocks and shows that the voltage mirror (VM) and current mirror (CM) are the basic pathological elements. The descriptions for the floating mirror elements in the nodal admittance matrix (NAM), using infinity-variables, are derived. The descriptions for nullator and norator using infinity-variables in the NAM are shown to represent special cases from the derived descriptions of the floating VM and the CM, respectively. Hence, new representations for the nullator and norator in terms of the floating VM and CM, respectively, are obtained. A systematic procedure for the derivation of pathological configurations to ideally represent various analog signal-processing properties featured by active building-blocks is presented. This systematic approach became plausible by virtue of the versatility offered by the NAM descriptions of floating mirror elements. Novel pathological configurations ideally describing most popular signal-processing properties that involve differential or multiple single-ended signals; like conversion between differential and single-ended voltages, differential voltage conveying, current differencing, differential current conveying, and inverting current replication; are derived systematically using this procedure. The resulting pathological configurations are shown to be constructed mainly using mirror elements and hence the capabilities of the mirrors as basic pathological elements are further demonstrated. Pathological representations for some active building-blocks, using the derived pathological sections, are presented as application examples. Copyright © 2008 John Wiley & Sons, Ltd. [source] VISCOSITY AND QUALITY OF TOMATO JUICE AS AFFECTED BY PROCESSING METHODSJOURNAL OF FOOD QUALITY, Issue 6 2007CHARANJIT KAUR ABSTRACT Quality and viscosity of tomato juice is strongly governed by mechanical and thermal abuse during processing. The effect of processing and storage duration on the viscosity and quality parameters of tomato juice was evaluated in the present work. Tomato juice was obtained by two different methods, normal method (NM) and variable method (VM), and was heated by both conventional and microwave hot break treatments. Tomato juice was evaluated for various quality characteristics including precipitate weight ratio, degree of serum separation (DOSS), Brookfield viscosity, lycopene levels, vitamin C, phenols and antioxidant activity. Changes observed in several quality parameters during storage were statistically insignificant. The methods and processing had the greatest contribution toward viscosity, whereas storage duration had no significant effects. Viscosity parameters viz precipitate weight, DOSS and Bostwick consistency revealed that juice processed by VM was more viscous than that of NM, irrespective of the hot break processing used. Ascorbic acid and lycopene content varied significantly with mechanical methods and processing conditions. However, phenolic content and antioxidant activity remained stable. The variable process represents an improvement over the conventional by enabling tomato processors to improve the consistency of the tomato product. PRACTICAL APPLICATIONS Quartering or slicing tomatoes followed by hot break processing techniques can significantly improve the quality of tomato juice in terms of reduced degree of serum separation and precipitate weight ratio. The modified technology could be considered as a viable and economical method for small- and medium-scale tomato processors with limited resources and facilities at their disposal. [source] Energy Consumption, Density, and Rehydration Rate of Vacuum Microwave- and Hot-Air Convection- Dehydrated TomatoesJOURNAL OF FOOD SCIENCE, Issue 6 2002T.D. Durance ABSTRACT: Vacuum to lower boiling temperature and microwaves for energy transfer can provide very rapid dehydration at low temperatures. Tomato sections were dehydrated in a batch convection air dryer (AD), a 16 kW vacuum microwave (VM) dryer, or by 1 of 3 combination processes. Drying rate of the 100% VM process was 18 times that of the 100% AD process. Only a slight falling rate effect was noted in VM drying AD and VM in sequence allowed the operator to choose any process time between 0.8 and 14.75 h. In this instance the least energy consumption occurred in the 100% VM process. Lowest energy cost was found for the 70% AD / 30% VM process. These results are expected to be strongly dependent upon the scale and design of dryers. Tomatoes finish-dried by VM exhibited a puffed structure associated with faster rehydration. [source] Three-dimensional finite element analysis of the facial skeleton on simulated occlusal loadingJOURNAL OF ORAL REHABILITATION, Issue 7 2001Martin D. Gross Development of predictive models of occlusal loading of the facial skeleton will be of value for prosthetic design in oral rehabilitation. A 3-D finite element (FE) model of a human skull, based on CT scans, was constructed to analyse strain and stress distribution in the facial skeleton caused by simulated occlusal loading. Vertical loads were applied simulating loading of the full maxillary arch and unilateral single point occlusal loading of maxillary molar, pre-molar, canine and incisor sites. Strain and stress regimes from Von Mises (VM) failure criteria and extension and compression diagrams showed even distribution of strain following loading of the full maxillary arch throughout the facial elements. For individual points, the highest VM concentrations were consistently located on the facial aspect several mm above the loading site. Strain trajectories divided into a ,V-shaped' pattern, from the loading point into medial and lateral branches with higher VM values in the medial. As the same load was applied from the posterior to anterior region, VM values increased on all facial areas. Strain patterns were less symmetric and there was an increase in strain in the alveolar arch and around the rim of the nasal cavity. The overall picture of the facial skeleton is of a vertical plate enabling it to withstand occlusal stresses by in-plane loading and bending in its own plane. The most efficient distribution of load was on maxillary full arch loading with the most unfavourable strain concentrations occurring on loading in the anterior region. [source] Effects of experimenting with physical and virtual manipulatives on students' conceptual understanding in heat and temperatureJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 9 2008Zacharias C. Zacharia Abstract This study aimed to investigate the comparative value of experimenting with physical manipulatives (PM) in a sequential combination with virtual manipulatives (VM), with the use of PM preceding the use of VM, and of experimenting with PM alone, with respect to changes in students' conceptual understanding in the domain of heat and temperature. A pre,post-comparison study design was used which involved 62 undergraduate students that attended an introductory course in physics. The participants were randomly assigned to one experimental and one control group. Both groups used the same inquiry-oriented curriculum materials. Participants in the control group used PM to conduct the experiments, whereas, participants in the experimental group used first PM and then VM. VM differed from PM in that it could provide the possibility of faster manipulation, whereas, it retained any other features and interactions of the study's subject domain identical to the PM condition. Conceptual tests were administered to assess students' understanding before, during, and after the study's treatments. Results indicated that experimenting with the combination of PM and VM enhanced students' conceptual understanding more than experimenting with PM alone. The use of VM was identified as the cause of this differentiation. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 1021,1035, 2008 [source] Linearity and reliability of the mechanomyographic amplitude versus dynamic torque relationships for the superficial quadriceps femoris musclesMUSCLE AND NERVE, Issue 3 2010Matthew S. Stock MS Abstract The purpose of this investigation was to examine the linearity and reliability of the mechanomyographic (MMG) amplitude versus dynamic torque relationships for the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) muscles. Nine healthy men and 11 healthy women performed submaximal to maximal, concentric, isokinetic muscle actions of the leg extensors at 30° s,1 on two occasions. Surface MMG signals were detected from the VL, RF, and VM of the dominant thigh during both trials. The ranges of the coefficients of determination for the MMG amplitude versus dynamic torque relationships were 0.01,0.94 for the VL, 0.01,0.84 for the RF, and 0.19,0.96 for the VM. The intraclass correlation coefficients for the linear MMG amplitude versus torque slope coefficients were 0.823 (VL), 0.792 (RF), and 0.927 (VM). These results indicate that, when analyzed for individual subjects, the MMG amplitude versus dynamic torque relationships demonstrated inconsistent linearity. When using MMG in the clinical setting, dynamic muscle actions of the superficial quadriceps femoris muscles do not appear to be appropriate for assessing changes in muscle function during strength training. Muscle Nerve, 2009 [source] Endoscopic treatment of symptomatic refluxing renal transplant ureteroneocystostomies in childrenPEDIATRIC TRANSPLANTATION, Issue 2 2010Vijaya M. Vemulakonda Vemulakonda VM, Koyle MA, Lendvay TS, Risk MC, Kirsch AJ, Cheng EY, Cisek LJ, Campbell JB. Endoscopic treatment of symptomatic refluxing renal transplant ureteroneocystostomies in children. Pediatr Transplantation 2010:14:212,215. © 2009 John Wiley & Sons A/S. Abstract:, To present a multi-center experience with the use of Dx/HA copolymer for treatment of symptomatic refluxing renal transplant UNC in children. A multi-center, retrospective chart review was performed. Eleven patients with a mean age of eight yr underwent renal transplantation with an anti-refluxing UNC. Data were collected to determine the safety and effectiveness of the procedure and to identify possible predictors of success. Endoscopic treatment was successful in one of five males and five of six females, for an overall success rate of 54.5%. The etiology of renal failure was associated with success of treatment, with 4/6 (67%) patients with upper tract pathology demonstrating resolution of the VUR, as compared with one of three (33%) patients with lower tract pathology. Male patients had a higher incidence of lower tract pathology. No complications were associated with the endoscopic procedure. Endoscopic injection of Dx/HA remains a safe option for the treatment of symptomatic refluxing transplant UNC in children. Although the success rate is lower than that seen in the treatment of primary VUR, the minimally invasive nature and safety of this technique may offer advantages over open reconstruction of the refluxing transplant ureter. [source] Spatially resolved defect studies on fatigued carbon steelPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 10 2007P. Eich Abstract Several samples of the common ferritic tool steel AISI 1045 were fatigued in cyclic load tests. The local distribution of the Von-Mieses stress ,VM was simulated using the finite elements method (FEM). In the regions of interest, where ,VM reaches maximum values, the defect distribution was measured spatially resolved by Doppler-spectroscopy (DBAR) employing the Bonn Positron Microprobe (BPM). The lateral distribution of the S-parameter, which could be described by a simple model derived from linear fracture mechanics, corresponds well with the simulated Von-Mieses stress. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Heterotic effects for yield and tuber solids and type of gene action for five traits in 4x potato families derived from interploid (4x-2x) crossesPLANT BREEDING, Issue 2 2000J. A. Buso Abstract The degree of heterosis for total tuber yield (TTY) and total solids (TS) in 4x-2x crosses was estimated by comparing the performance of 12 families with their respective parents in two locations in Wisconsin (USA). The parental 2x clones were Phureja-haploid Tuberosum hybrids with 2n -pollen production by first-division restitution. The general combining ability (GCA) and specific combining ability (SCA) were estimated for TTY, TS, vine maturity (VM), length of tuber sprout dormancy (LD), and tuber eye depth (ED). Family performance for TTY ranged from 74 to 146% at Hancock (E#1) and from 77 to 287 at Rhinelander (E#2) when compared with that of the 4x parent group. For VM, the families were late maturing, but a few precocious ones were identified. For TS, the families had heterosis of 5.1% over the 4x parent group. The families had slightly higher ED values than the 4x parents, but families with values within the commercial range were identified. The family average for LD (54 days) was closer to the 2x group (51 days) than to the 4x group (88 days). The direction and magnitude of the parent-family relationships were variable. The 4x parent TTY was correlated with progeny in E#1 but not E#2. The 2x parent VM had correlation with the offspring at E#2 but not at E#1. The type of gene action had a trait-specific expression. Significant SCA and GCA variances were observed, suggesting that additive as well as non-additive genetic effects were operating. The 4x-2x crosses were able to generate heterotic families for TTY and TS in combination with other useful traits. However, no promising results were found for LD because of the apparent dominance of the short-dormancy phenotype. This result indicates the need of additional selection and breeding efforts for some specific traits when using S. phureja -derived germplasm. [source] Viral ssRNA Induces First Trimester Trophoblast Apoptosis through an Inflammatory MechanismAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 1 2010Paulomi B. Aldo Citation Aldo PB, Mulla MJ, Romero R, Mor G, Abrahams VM. Viral ssRNA induces first-trimester trophoblast apoptosis through an inflammatory mechanism. Am J Reprod Immunol 2010; 64: 27,37 Problem, Infection during pregnancy represents a significant cause of mobility and mortality. While viruses pose a major threat, little is known about their effect on early pregnancy, or the mechanisms involved. The objective of this study was to characterize the trophoblast response following exposure to viral ssRNA. Method of study, First trimester trophoblast cells were treated with or without viral ssRNA. Cytokine production was measured using multiplex analysis and ELISA. Apoptosis was determined using Hoechst staining, cell viability, and caspase activity assays. Results, Treatment of trophoblasts with viral ssRNA increased their secretion of IL-8, IL-6, and IFN,. However, the ssRNA also induced trophoblast apoptosis. To test whether the viral ssRNA-induced inflammatory response was responsible for this induction of apoptosis, conditioned media (CM) from trophoblasts were added to a fresh culture of cells. The CM from viral ssRNA-treated induced higher levels of trophoblast apoptosis than the control CM. Moreover, recombinant IFN, induced trophoblast apoptosis. Conclusion, We demonstrate that viral ssRNA induces a pro-inflammatory and type I interferon response in the trophoblast and this inflammatory process may indirectly induce trophoblast apoptosis. These results provide a novel mechanism by which certain viral infections might compromise placental integrity and function, and therefore, pregnancy outcome. [source] ORIGINAL ARTICLE: Antiphospholipid Antibodies Limit Trophoblast Migration by Reducing IL-6 Production and STAT3 ActivityAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 5 2010Melissa J. Mulla Citation Mulla MJ, Myrtolli K, Brosens JJ, Chamley LW, Kwak-Kim JY, Paidas MJ, Abrahams VM. Antiphospholipid antibodies limit trophoblast migration by reducing IL-6 production and STAT3 activity. Am J Reprod Immunol 2010 Problem Women with antiphospholipid antibodies (aPL) are at risk of recurrent miscarriage and pre-eclampsia. aPL target the placenta by binding to ,2 -glycoprotein I (,2 GPI) expressed by the trophoblast. The objective of this study was to evaluate if and how aPL affect first trimester trophoblast migration. Method of study First trimester trophoblast cells were treated with anti-,2 GPI monoclonal antibodies. Migration was determined using a two-chamber assay. Interleukin (IL)-6 production was evaluated by RT-PCR and enzyme-linked immunosorbent assay, and signal transducer and activator of transcription 3 (STAT3) activation was assessed by western blot. Results Trophoblast cells constitutively secreted IL-6 in a time-dependent manner and this directly correlated with STAT3 phosphorylation. In the presence of anti-,2 GPI Abs, trophoblast IL-6 mRNA levels and secretion was downregulated in a Toll-like receptor 4/MyD88-independent manner and this correlated with a reduction in phosphorylated STAT3 levels. In addition, the anti-,2 GPI Abs reduced the migratory potential of trophoblast. Heparin was able to reverse aPL-dependent inhibition of trophoblast IL-6 secretion and migration. Conclusion This study demonstrates that aPL limit trophoblast cell migration by downregulating trophoblast IL-6 secretion and STAT3 activity. As heparin was unable to prevent these effects, our findings may explain why women with antiphospholipid syndrome, treated with heparin, remain at risk of developing obstetrical syndromes, associated with impaired deep placentation, such as pre-eclampsia. [source] No cerebrocervical venous congestion in patients with multiple sclerosis,ANNALS OF NEUROLOGY, Issue 2 2010Florian Doepp MD Objective: Multiple sclerosis (MS) is characterized by demyelination centered around cerebral veins. Recent studies suggested this topographic pattern may be caused by venous congestion, a condition termed chronic cerebrospinal venous insufficiency (CCSVI). Published sonographic criteria of CCSVI include reflux in the deep cerebral veins and/or the internal jugular and vertebral veins (IJVs and VVs), stenosis of the IJVs, missing flow in IJVs and VVs, and inverse postural response of the cerebral venous drainage. Methods: We performed an extended extra- and transcranial color-coded sonography study including analysis of extracranial venous blood volume flow (BVF), cross-sectional areas, IJV flow analysis during Valsalva maneuver (VM), and CCSVI criteria. Fifty-six MS patients and 20 controls were studied. Results: Except for 1 patient, blood flow direction in the IJVs and VVs was normal in all subjects. In none of the subjects was IJV stenosis detected. IJV and VV BVF in both groups was equal in the supine body position. The decrease of total jugular BVF on turning into the upright position was less pronounced in patients (173 ± 235 vs 362 ± 150ml/min, p < 0.001), leading to higher BVF in the latter position (318ml/min ± 242 vs 123 ± 109ml/min; p < 0.001). No differences between groups were seen in intracranial veins and during VM. None of the subjects investigated in this study fulfilled >1 criterion for CCSVI. Interpretation: Our results challenge the hypothesis that cerebral venous congestion plays a significant role in the pathogenesis of MS. Future studies should elucidate the difference between patients and healthy subjects in BVF regulation. ANN NEUROL 2010;68:173,183 [source] Crystallization and preliminary crystallographic studies of MOMP (major outer membrane protein) from Campylobacter jejuniACTA CRYSTALLOGRAPHICA SECTION D, Issue 12-2 2004Jean Michel Bolla Campylobacter jejuni is the leading bacterial cause of human enteritis linked to ingestion of contaminated food or water. MOMP, the major outer membrane protein from these Gram-negative bacteria, belongs to the porin family. In order to determine the three-dimensional structure of this protein and to elucidate the underlying molecular mechanisms, the MOMP from C. jejuni strain 85H has been purified and crystallized by vapour diffusion. Two crystal forms were characterized for this membrane protein. X-ray diffraction data were collected to a resolution of 3.1,Å using a synchrotron-radiation source from the orthorhombic crystal form, which belonged to space group P21212 with unit-cell parameters a = 170.1, b = 101.9, c = 104.9,Å. With a trimer in the asymmetric unit, the solvent content is 64% (VM = 3.4,Å,Da,1). The other form exhibits trigonal symmetry (space group R3) with hexagonal unit-cell parameters a = b = 94.2, c = 161.2,Å, but diffracts X-rays poorly to about 4,Å with significant anisotropy. [source] Crystallization and preliminary X-ray crystallographic analysis of a non-specific lipid-transfer protein with antipathogenic activity from Phaseolus mungoACTA CRYSTALLOGRAPHICA SECTION D, Issue 12-2 2004Shao-Yun Wang A 9,kDa non-specific lipid-transfer protein (nsLTP) from mung bean (Phaseolus mungo) seeds, displaying antifungal activity, antibacterial activity and lipid-transfer activity, was crystallized at 297,K using ammonium sulfate as a precipitant by means of the hanging-drop vapour-diffusion method. Native X-ray diffraction data were collected to a resolution of 2.4,Å. The crystals are rhombohedral, belonging to space group P212121, with unit-cell parameters a = 38.671, b = 51.785, c = 55.925,Å. Assuming the presence of one molecule in the crystallographic asymmetric unit results in a Matthews coefficient (VM) of approximately 3.0,Å3,Da,1, corresponding to a solvent content of about 58%. [source] Crystallization and preliminary analysis of a water-forming NADH oxidase from Lactobacillus sanfranciscensisACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2004George T. Lountos Single crystals have been obtained of NADH oxidase (Nox), a flavoenzyme cloned from Lactobacillus sanfranciscensis. The enzyme catalyzes the oxidation of two equivalents of NAD(P)H and reduces one equivalent of oxygen to yield two equivalents of water, without releasing hydrogen peroxide after the reduction of the first equivalent of NAD(P)H. The enzyme crystallizes in space group P212121, with unit-cell parameters a = 59.6, b = 92.6, c = 163.5,Å. The crystals diffract to 1.85,Å resolution using synchrotron radiation. Matthews coefficient calculations suggest the presence of two molecules per asymmetric unit (VM = 2.3,Å3,Da,1, 45.5% solvent content), which has been confirmed by the molecular-replacement solution using a search molecule derived from NADH peroxidase (PDB code 1f8w). [source] Cloning, expression, purification and crystallization of a transcriptional regulatory protein (Rv3291c) from Mycobacterium tuberculosis H37RvACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2004Tripti Shrivastava Rv3291c, the translational product of the Mycobacterium tuberculosisRv3291c gene, is an 18,kDa protein. It is a putative transcriptional regulatory protein belonging to the leucine-responsive regulatory protein/asparagine synthase C (Lrp/AsnC) family, which are proteins that have been identified in archaea and bacteria. Rv3291c probably plays a significant role during the persistent/latent phase of M. tuberculosis, as supported by its up-regulation several-fold during this stage. Orthorhombic crystals of recombinant Rv3291c have been grown from trisodium citrate dihydrate-buffered solutions containing monoammonium dihydrogen phosphate. Diffraction data extending to 2.7,Å have been collected from a single crystal with unit-cell parameters a = 99.6, b = 100.7, c = 100.6,Å. Assuming an octamer in the asymmetric unit results in a Matthews coefficient (VM) of 1.75,Å3,Da,1, corresponding to a solvent content of about 30%. [source] Crystallization and preliminary X-ray analysis of Escherichia coli MutT in binary and ternary complex formsACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2004Teruya Nakamura During replication, Escherichia coli MutT prevents the misincorporation of mutagenic 8-oxoguanine into nascent DNA strands opposite adenine by hydrolyzing 8-oxo-dGTP in nucleotide pools to 8-oxo-dGMP. E. coli MutT is the most widely investigated member of the Nudix hydrolase family, which is large and found in all organisms. By co-crystallization of MutT with 8-oxo-dGMP, a reaction product, crystals of the binary complex were obtained using ammonium sulfate as a precipitant. The crystals belong to space group P212121, with unit-cell parameters a = 37.9, b = 56.0, c = 59.4,Å. Assuming the presence of one protein,nucleotide complex in the asymmetric unit, the Matthews coefficient VM is 2.1,Å3,Da,1. Crystals of the ternary complex were prepared by soaking crystals of the binary complex in 1,mM MnCl2 solution. They diffracted to 1.96 and 2.56,Å resolution, respectively. [source] Purification, crystallization, X-ray diffraction analysis and phasing of a Fab fragment of monoclonal neuroantibody ,D11 against nerve growth factorACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2004Sonia Covaceuszach The rat monoclonal neuroantibody ,D11 is a potent antagonist that prevents the binding of nerve growth factor (NGF) to its tyrosine kinase A receptor (TrkA) in a variety of systems, most notably in two in vivo systems linked to crucial pathological states, such as Alzheimer's disease and HIV infection. To provide further insights into the mechanism of action of this potentially therapeutic monoclonal antibody, structural studies of the antigen-binding fragment (Fab) of ,D11 were performed. ,D11 IgG2a immunoglobulin was obtained from hybridomas by in vitro tissue culture. The ,D11 Fab crystallizes in two crystal forms. Form I belongs to space group P1, with unit-cell parameters a = 42.7, b = 50.6, c = 102.7,Å, , = 82.0, , = 89.1, , = 86.0°. With two molecules in the asymmetric unit, VM is 2.3,Å3,Da,1 and the solvent content is 46%. A complete data set has been collected at 2.7,Å resolution on beamline XRD-1 (ELETTRA, Trieste, Italy). Form II belongs to space group C2, with unit-cell parameters a = 114.8, b = 69.4, c = 64.10,Å, , = 117.0°. With one molecule in the asymmetric unit, VM is 2.4,Å3,Da,1 and the solvent content is 48%. A complete data set has been collected at 1.7,Å resolution on beamline ID14-1 (ESRF, Grenoble, France). Phasing was successfully performed by Patterson search techniques and refinement of the structures is currently under way. Crystal forms I and II display a close-packing pattern. [source] Crystallization and preliminary X-ray crystallographic analysis of nicotinic acid mononucleotide adenylyltransferase from Pseudomonas aeruginosaACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2004Hye-Lee Kim The enzyme nicotinic acid mononucleotide adenylyltransferase (NaMN AT; EC 2.7.7.18) is essential for the synthesis of nicotinamide adenine dinucleotide and is a potential target for antibiotics. It catalyzes the transfer of an adenyl group from ATP to nicotinic acid mononucleotide to form nicotinic acid adenine dinucleotide. NaMN AT from Pseudomonas aeruginosa was overexpressed in Escherichia coli and crystallized at 291,K using 100,mM bis,Tris propane pH 7.0, 700,mM trisodium citrate and 15%(v/v) glycerol. X-ray diffraction data have been collected to 1.70,Å. The crystals are tetragonal, belonging to space group P4122 (or P4322), with unit-cell parameters a = b = 65.02, c = 109.80,Å. The presence of one monomer in the asymmetric unit gives a reasonable VM of 2.15,Å3,Da,1, with a solvent content of 42.7%. [source] Characterization, crystallization and preliminary X-ray analysis of bifunctional dihydrofolate reductase,thymidylate synthase from Plasmodium falciparumACTA CRYSTALLOGRAPHICA SECTION D, Issue 4 2004Penchit Chitnumsub The full-length pfdhfr-ts genes of the wild-type TM4/8.2 and the double mutant K1CB1 (C59R+S108N) from the genomic DNA of the corresponding Plasmodium falciparum parasite have been cloned into a modified pET(17b) plasmid and expressed in Escherichia coli BL21 (DE3) pLysS. Conditions for the expression and purification of the P. falciparum dihydrofolate reductase,thymidylate synthase (PfDHFR-TS) have been established that yield ,1,mg of the soluble active enzyme per litre of culture. The purified enzymes have been crystallized using a modified microbatch method with PEG 4000 as the primary precipitating agent. X-ray diffraction data were collected to 2.50 and 2.64,Å resolution under cryogenic conditions from single crystals of the two PfDHFR-TS proteins in complex with NADPH, dUMP and either Pyr30 or Pyr39. Preliminary X-ray analysis indicated that the crystals belong to the orthorhombic space group P212121, with two molecules per asymmetric unit and ,52% solvent content (VM, 2.6,Å3,Da,1). The use of a particular type of baby oil in the microbatch setup appeared to be beneficial to PfDHFR-TS crystallization and a preliminary comparison with another commonly used oil is described. [source] Crystallization and preliminary X-ray crystallographic analysis of the RecR protein from Deinococcus radiodurans, a member of the RecFOR DNA-repair pathwayACTA CRYSTALLOGRAPHICA SECTION D, Issue 2 2004Byung Il Lee The RecR protein plays a key role in the RecFOR pathway of recombination, which is necessary for the repair of ssDNA gaps. RecR from Deinococcus radiodurans has been overexpressed in Escherichia coli and crystallized at 297,K using polyethylene glycol 1000 as a precipitant. X-ray diffraction data to 2.90,Å resolution have been collected at 100,K using Cu,K, X-rays from a mercury-soaked crystal. The crystal belongs to space group C2221, with unit-cell parameters a = 106.96, b = 122.25, c = 156.01,Å. The asymmetric unit contains four monomers of RecR, with a crystal volume per protein weight (VM) of 2.57,Å3,Da,1 and a solvent content of 51.0%. [source] Structural genomics of the SARS coronavirus: cloning, expression, crystallization and preliminary crystallographic study of the Nsp9 proteinACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2003Valérie Campanacci The aetiologic agent of the recent epidemics of Severe Acute Respiratory Syndrome (SARS) is a positive-stranded RNA virus (SARS-CoV) belonging to the Coronaviridae family and its genome differs substantially from those of other known coronaviruses. SARS-CoV is transmissible mainly by the respiratory route and to date there is no vaccine and no prophylactic or therapeutic treatments against this agent. A SARS-CoV whole-genome approach has been developed aimed at determining the crystal structure of all of its proteins or domains. These studies are expected to greatly facilitate drug design. The genomes of coronaviruses are between 27 and 31.5,kbp in length, the largest of the known RNA viruses, and encode 20,30 mature proteins. The functions of many of these polypeptides, including the Nsp9,Nsp10 replicase-cleavage products, are still unknown. Here, the cloning, Escherichia coli expression, purification and crystallization of the SARS-CoV Nsp9 protein, the first SARS-CoV protein to be crystallized, are reported. Nsp9 crystals diffract to 2.8,Å resolution and belong to space group P61/522, with unit-cell parameters a = b = 89.7, c = 136.7,Å. With two molecules in the asymmetric unit, the solvent content is 60% (VM = 3.1,Å3,Da,1). [source] Crystallization and preliminary X-ray data investigation of the bacterial enterocin A immunity protein at 1.65,Å resolutionACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2003Bjørn Dalhus Crystals of the bacterial enterocin A immunity protein have been prepared by the hanging-drop vapour-diffusion technique at 293,K. The crystals diffract to better than 1.7,Å resolution and X-ray diffraction data to 1.65,Å have been collected at 110,K using synchrotron radiation. The enterocin A immunity protein crystals belong to the monoclinic crystal system, with unit-cell parameters a = 116.32, b = 42.35, c = 66.17,Å, , = 111.3°. The symmetry and systematic absences in the diffraction pattern are consistent with space group C2. The presence of two molecules in the asymmetric unit with a molecular weight of ,12.2,kDa gives a crystal volume per protein mass (VM) of ,3.1,Å3,Da,1 and a solvent content of ,60% by volume. [source] Crystallization and preliminary X-ray characterization of a novel calcium-binding protein AtCBL2 from Arabidopsis thalianaACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2003Masamichi Nagae A new family of calcineurin B-like calcium-binding proteins has recently been identified in Arabidopsis thaliana. AtCBL2, a member of this family, has been crystallized in the presence of calcium ions using polyethylene glycol as a precipitant at 293,K. The crystals belong to space group C2221, with unit-cell parameters a = 83.9, b = 118.1, c = 49.1,Å. The asymmetric unit contains one molecule, with a VM of 2.36,Å3,Da,1 and a solvent content of 48%. Native diffraction data to 2.1,Å resolution have been collected using synchrotron radiation at SPring-8. [source] Crystallization and preliminary crystallographic analysis of extracellular fragment X3 of YWK-II/APPH: a human sperm membrane protein related to the Alzheimer ,A4-amyloid precursor proteinACTA CRYSTALLOGRAPHICA SECTION D, Issue 3 2003Wangjun Hu Crystals of extracellular fragment X3 of a human sperm membrane protein YWK-II/APPH have been grown at 291,K using 8% PEG 4000 as precipitant by the vapour-diffusion method. The diffraction pattern of the crystal extends to 2.9,Å resolution at 100,K using Cu,K, radiation in-house. The crystals belong to space group P21, with unit-cell parameters a = 46.0, b = 43.7, c = 90.2,Å, , = , = 90.0, , = 106.6°. Furthermore, a selenomethionine (SeMet) derivative of the protein was overexpressed in the same expression system and was purified in a reducing environment. The derivative crystals were obtained under similar conditions. Subsequently, a single-wavelength data set was collected to 2.38,Å resolution from the derivative crystal at ESRF. The crystals belong to space group P21, with unit-cell parameters a = 46.2, b = 44.0, c = 88.3,Å, , = , = 90.0, , = 103.6°. The presence of one molecule per asymmetric unit gives a crystal volume per protein mass (VM) of 2.8,Å3,Da,1 and a solvent content of 56.4% by volume. [source] Crystallization and preliminary crystallographic analysis of a partial extracellular fragment of a sperm membrane protein YWK-II/APPH related to the Alzheimer ,A4-amyloid precursor proteinACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2003Maojun Yang Crystals of a partial extracellular fragment of a human sperm membrane protein YWK-II/APPH have been grown at 291,K using PEG 4000 as precipitant. The diffraction pattern of the crystal extends to 2.8,Å resolution at 100,K using Cu,K, radiation. The crystals belong to space group P212121, with unit-cell parameters a = 46.009, b = 67.387, c = 149.241,Å, , = , = , = 90°. The presence of two molecules per asymmetric unit gives a crystal volume per protein mass (VM) of 3.51,Å3,Da,1 and a solvent content of 64.6% by volume. A full set of X-ray diffraction data were collected to 2.8,Å resolution from the native crystal. [source] Physical-mechanical properties of glass ionomer cements indicated for atraumatic restorative treatmentAUSTRALIAN DENTAL JOURNAL, Issue 3 2009CC Bonifácio Abstract Background:, This study evaluated mechanical properties of glass ionomer cements (GICs) used for atraumatic restorative treatment. Wear resistance, Knoop hardness (Kh), flexural (Fs) and compressive strength (Cs) were evaluated. The GICs used were Riva Self Cure (RVA), Fuji IX (FIX), Hi Dense (HD), Vitro Molar (VM), Maxxion R (MXR) and Ketac Molar Easymix (KME). Methods:, Wear was evaluated after 1, 4, 63 and 365 days. Two-way ANOVA and Tukey post hoc tests (P = 0.05) analysed differences in wear of the GICs and the time effect. Fs, Cs, and Kh were analysed with one-way ANOVA. Results:, The type of cement (p < 0.001) and the time (p < 0.001) had a significant effect on wear. In early-term wear and Kh, KME and FIX presented the best performance. In long-term wear, Fs and Cs, KME, FIX and HD had the best performance. Strong explanatory power between Fs and the Kh (r2 = 0.85), Cs and the Kh (r2 = 0.82), long-term wear and Fs of 24 h (r2 = 0.79) were observed. Conclusions:, The data suggested that KME and FIX presented the best in vitro performance. HD showed good results except for early-term wear. [source] Crystallization and preliminary X-ray crystallographic analysis of peptide deformylase from Pseudomonas aeruginosaACTA CRYSTALLOGRAPHICA SECTION D, Issue 10-2 2002Hyung-Wook Kim Peptide deformylase (PDF) from the pathogenic bacterium Pseudomonas aeruginosa has been overexpressed in Escherichia coli and crystallized in the presence of its inhibitor actinonin at 297,K using polyethylene glycol (PEG) 4000 as a precipitant. The diffraction limit and the spot shape of the crystals could be slightly improved by the crystal annealing/dehydration procedure. X-ray diffraction data to 1.85,Å have been collected using synchrotron radiation. The crystal belongs to the orthorhombic space group P212121, with unit-cell parameters a = 68.75, b = 74.46, c = 77.18,Å. The asymmetric unit contains two subunits of peptide deformylase, with a corresponding crystal volume per protein mass (VM) of 2.45,Å3,Da,1 and a solvent content of 49.8%. [source] | |||||||||||||||||||