Differences In Peak Intensities Research Articles

Human neutrophil peptides 1–3 are useful biomarkers in patients with active ulcerative colitis

A specific useful biomarker for diagnosing ulcerative colitis (UC) has not yet been described. This study employed proteomics to identify serum protein biomarkers for UC. Ninety-four blood samples were isolated from patients and controls (including 48 UC, 22 Crohn's disease [CD], 5 colorectal cancer, and 6 infectious colitis patients and 13 healthy subjects). Serum samples were analyzed using the SELDI-TOF/MS ProteinChip system. After applying the samples to ProteinChip arrays, we assessed differences in the proteomes using Ciphergen ProteinChip software and identified candidate proteins, which were then characterized in immunoassays. Preliminary analysis using the ProteinChip system revealed significant peak-intensity differences for 27 serum proteins between 11 patients with UC and 7 healthy subjects. Among these proteins, 3 proteins (with mass/charge ratios of approximately 3400) were identified as human neutrophil peptides 1-3 (HNP 1-3). The presence of HNP 1-3 in the patient sera was confirmed using immunoassays. Enzyme-linked immunosorbent assays demonstrated that the mean plasma concentration of HNP 1-3 was significantly higher in patients with active UC (n = 28) than in patients whose UC was in remission (n = 20) or patients with CD (n = 22), infectious colitis, or healthy subjects, and tended to be higher than in patients with colon cancer. In addition, the plasma concentration of HNP 1-3 in patients that responded to corticosteroids-based therapy decreased after treatment, whereas it was not changed in nonresponders. HNP 1-3 is a novel biomarker that may be useful for diagnosing patients with active UC and predicting treatment outcomes.

The role of rare earth metals in lanthanide-incorporated mesoporous titania

Cerium and lanthanum-incorporated mesoporous TiO 2 with up to 10 mol% metal were synthesized by a sol–gel method using a neutral structure-directing agent. The textural properties and surface structure of samples were investigated by means of N 2 sorption measurements, SEM images and XRD patterns. The doping of lanthanide elements resulted in not only an increase in the surface area, pore volume and average pore size of mesoporous TiO 2, but also in inhibition of mesostructure collapse and the growth of TiO 2 nanocrystallites. In both cerium and lanthanum-incorporated mesoporous TiO 2, the fact that only the anatase TiO 2 phase was present indicated substantial incorporation of metal species into the framework or significant dispersion inside the channel. However, Ce and La-incorporated mesoporous TiO 2 differed with regard to the surface chemical states of the metal elements. According to XPS of xCe-TiO 2 powders, Ti mainly existed in a coordinatively unsaturated titanium (IV) state for low doping amounts, whereas the Ti 3+ state was observed when the Ce/Ti ratio exceeded one. In contrast, no apparent difference in peak intensity and position was seen for lanthanum samples. While only the La 3+ state was found in xLa–TiO 2, Ce 3d spectra showed a mixture of Ce 3+/4+ oxidation states on the surface which led to changes in the chemical environment of oxygen.

Platelet Factor-4 Is an Indicator of Blood Count Recovery in Acute Myeloid Leukemia Patients in Complete Remission

To investigate whether serum biomarkers can be used to indicate the responsiveness of acute myeloid leukemia to remission induction chemotherapy, we performed MALDI-TOF protein profile analysis of patient sera. The resulting spectra revealed a protein (or peptide) peak at m/z 7764 that varied in intensity; its intensity was much higher in samples from patients in complete remission than in those from patients with resistant disease or in samples taken prior to treatment (at the time of diagnosis). Using fractionation, trypsin digestion, MS/MS, and protein molecular weight analyses, we identified the m/z 7764 protein as platelet factor-4 (PF4). This identification was confirmed by a magnetic bead-based MALDI immunoassay. Statistical comparison of PF4 levels and platelet counts in patient sera revealed a significant positive correlation between the two variables. This study demonstrates that PF4 protein levels are a good indicator for the recovery of blood count in the complete remission of acute myeloid leukemia. The linear positive correlation curve indicates that blood count recovery of platelets to >100,000/mm(3) is equivalent to a serum PF4 recovery level of >2.492 microg/ml.

Independent component analysis for the extraction of reliable protein signal profiles from MALDI-TOF mass spectra

Independent component analysis (ICA) is a signal processing technique that can be utilized to recover independent signals from a set of their linear mixtures. We propose ICA for the analysis of signals obtained from large proteomics investigations such as clinical multi-subject studies based on MALDI-TOF MS profiling. The method is validated on simulated and experimental data for demonstrating its capability of correctly extracting protein profiles from MALDI-TOF mass spectra. The comparison on peak detection with an open-source and two commercial methods shows its superior reliability in reducing the false discovery rate of protein peak masses. Moreover, the integration of ICA and statistical tests for detecting the differences in peak intensities between experimental groups allows to identify protein peaks that could be indicators of a diseased state. This data-driven approach demonstrates to be a promising tool for biomarker-discovery studies based on MALDI-TOF MS technology. The MATLAB implementation of the method described in the article and both simulated and experimental data are freely available at http://www.unich.it/proteomica/bioinf/.

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Serum proteomic patterns for gastric lesions as revealed by SELDI mass spectrometry

SELDI mass spectrometry was used to investigate protein expression in sera of patients with gastric cancer and gastritis compared to normal volunteers. Differences in peak morphology and intensity were observed in regions of 5910 Da, 5084 Da, 6640 Da and 8691 Da. Patients with gastric cancer exhibited an up-regulation of the 5910 Da peak and a down-regulation of the 8691 Da peak compared to the healthy volunteers; there was also some bi-partitioning and tri-partitioning at the 5084 Da peak. When comparing the sera of these cancer patients with those of gastritis, the former had an up-regulation of the 5910 Da peak and a down-regulation of the 6640 Da peak. This is the first report showing that SELDI sera analysis may be useful in the screening of gastric lesions.

Quantitative Proteomic Analysis of Post-translational Modifications of Human Histones

Histone proteins are subject to a range of post-transcriptional modifications in living cells. The combinatorial nature of these modifications constitutes the "histone code" that dictates chromatin structure and function during development, growth, differentiation, and homeostasis of cells. Deciphering of the histone code is hampered by the lack of analytical methods for monitoring the combinatorial complexity of reversible multisite modifications of histones, including acetylation and methylation. To address this problem, we used LC-MSMS technology and Virtual Expert Mass Spectrometrist software for qualitative and quantitative proteomic analysis of histones extracted from human small cell lung cancer cells. A total of 32 acetylations, methylations, and ubiquitinations were located in the human histones H2A, H2B, H3, and H4, including seven novel modifications. An LC-MSMS-based method was applied in a quantitative proteomic study of the dose-response effect of the histone deacetylase inhibitor (HDACi) PXD101 on histone acetylation in human cell cultures. Triplicate LC-MSMS runs at six different HDACi concentrations demonstrated that PXD101 affects acetylation of histones H2A, H2B, H3, and H4 in a site-specific and dose-dependent manner. This unbiased analysis revealed that a relative increase in acetylated peptide from the histone variants H2A, H2B, and H4 was accompanied by a relative decrease of dimethylated Lys(57) from histone H2B. The dose-response results obtained by quantitative proteomics of histones from HDACi-treated cells were consistent with Western blot analysis of histone acetylation, cytotoxicity, and dose-dependent expression profiles of p21 and cyclin A2. This demonstrates that mass spectrometry-based quantitative proteomic analysis of post-translational modifications is a viable approach for functional analysis of candidate drugs, such as HDAC inhibitors.

CCS and NH3Emission Associated with Low‐Mass Young Stellar Objects

In this work we present a sensitive and systematic single-dish survey of CCS emission (complemented with ammonia observations) at 1 cm, toward a sample of low- and intermediate-mass young star-forming regions known to harbor water maser emission, made with NASA's 70 m antenna at Robledo de Chavela, Spain. Out of the 40 star-forming regions surveyed in the CCS (2_(1)-1_(0)) line, only six low-mass sources show CCS emission: one transitional object between the prestellar and protostellar Class 0 phase (GF9-2), three Class 0 protostars (L1448-IRS3, L1448C, and B1-IRS), a Class I source (L1251A), and a young T Tauri star (NGC 2071 North). Since CCS is considered an early-time (≲10^5 yr) molecule, we explain these results by either proposing a revision of the classification of the age of NGC 2071 North and L1251A, or suggesting the possibility that the particular physical conditions and processes of each source affect the destruction/production of the CCS. No statistically significant relationship was found between the presence of CCS and parameters of the molecular outflows and their driving sources. Nevertheless, we found a significant relationship between the detectability of CCS and the ammonia peak intensity (higher in regions with CCS), but not with its integrated intensity. This tendency may suggest that the narrower ammonia line widths in the less turbulent medium associated with younger cores may compensate for the differences in ammonia peak intensity, rendering differences in integrated intensity negligible. From the CCS detection rate we derive a lifetime of this molecule of ≃(0.7-3) × 10^4 yr in low-mass star-forming regions.

Assessment of Coronary Arterial Thrombus by Optical Coherence Tomography

We analyzed optical coherence tomographic (OCT) characteristics of different types of coronary thrombi that had been confirmed at postmortem histologic examination. We examined 108 coronary arterial segments of 40 consecutive human cadavers. OCT images of red and white thrombi were obtained and the intensity property of these thrombi was analyzed. Red and white thrombi were found in 16 (17%) and 19 (18%) of the 108 arterial segments, respectively. Red thrombi were identified as high-backscattering protrusions inside the lumen of the artery, with signal-free shadowing in the OCT image. White thrombi were identified as low-backscattering projections in the OCT image. There were no significant differences in peak intensity of OCT signal between red and white thrombi (130+/-18 vs 145+/-34, p=0.12). However, the 1/2 attenuation width of the signal intensity curve, which was defined as the distance from peak intensity to its 1/2 intensity, was significantly different between red and white thrombi (324+/-50 vs 183+/- 42 microm, p<0.0001). A cut-off value of 250 microm in the 1/2 width of signal intensity attenuation can differentiate white from red thrombi with a sensitivity of 90% and specificity of 88%. We present the first detailed description of the characteristics of different types of coronary thrombi in OCT images. Optical coherence tomography may allow us not only to estimate plaque morphology but also to distinguish red from white thrombi.

Proteomic study of plasma proteins in pregnant women with asthma

The course of asthma may be altered during pregnancy with at least one-third of women experiencing a worsening of asthma and 20% having an exacerbation during pregnancy. This study used the novel proteomic technique, surface-enhanced laser desorption ionization-time of flight mass spectrometry to determine if the presence of asthma during pregnancy was associated with alterations in plasma proteins. Plasma collected from healthy (n = 23) and asthmatic (n = 27) pregnant women at 18 and 30 weeks gestation was applied to strong anion exchange (SAX2), weak cation exchange (WCX2) and immobilized metal affinity capture (IMAC-Cu(2+)) chips. Mass analysis was conducted using Ciphergen Protein Biology System IIc and significant differences in individual peak intensities between groups determined. At 18 weeks gestation, 91 peaks were significantly different between pregnant women with and without asthma, representing 28% of the total peaks identified. At 30 weeks gestation, 51 peaks were significantly different. There were two peaks that were significantly different between groups at both 18 and 30 weeks gestation and expressed at a similar level at both time points. One was increased in asthmatics (MW = 6444 Da) whereas the other decreased in asthmatics compared with non-asthmatic women (MW = 1846 Da). This study demonstrated that there are differences in protein patterns between pregnant women with and without asthma. Other techniques are needed to define the molecular species and classify pathophysiological significance. Surface-enhanced laser desorption ionization-time of flight mass spectrometry has potential as a tool to monitor disease progression in situations such as pregnancy.

The Effect of Maternal Asthma on Placental and Cord Blood Protein Profiles

We conducted a comparative proteomic analysis of placental and umbilical cord blood proteins using surface-enhanced laser desorption ionization-time of flight mass spectrometry (SELDI-TOF MS) to examine the associations among asthma, fetal gender, and protein profiles. Placental tissue and umbilical vein plasma were collected from 10 healthy and 20 asthmatic women. Placental proteins were extracted using phosphate-buffered saline containing protease inhibitors. Samples were applied to the surfaces of strong anion exchange (SAX2), weak cation exchange (WCX2) and immobilized metal affinity capture (IMAC-Cu(2+)) chips. Mass analysis was conducted using a Ciphergen Protein Biology System IIc (Freemont, CA), and differences in individual peak intensities between groups were determined. Fourteen placental peaks were significantly different between asthmatic and non-asthmatic women (seven more highly expressed and seven less highly expressed). Ten umbilical cord blood peak differences were identified, with four peaks more highly expressed and six peaks less highly expressed in asthmatics. Four placental and three umbilical cord blood proteins differed significantly between male and female fetuses. Two placental and five umbilical cord blood peaks were specifically increased in a subgroup of samples collected from asthmatic women who did not use inhaled glucocorticoids and were pregnant with a female fetus, a group previously found to have altered placental function. This study demonstrates the abilities of the SELDI technique as a tool for protein profiling in tissue or plasma. Further work to positively identify the candidate peptides found in this study may provide a greater understanding of the placental mechanisms leading to alterations in fetal growth in patients with bronchial asthma.

How to track and assess genotyping errors in population genetics studies.

Genotyping errors occur when the genotype determined after molecular analysis does not correspond to the real genotype of the individual under consideration. Virtually every genetic data set includes some erroneous genotypes, but genotyping errors remain a taboo subject in population genetics, even though they might greatly bias the final conclusions, especially for studies based on individual identification. Here, we consider four case studies representing a large variety of population genetics investigations differing in their sampling strategies (noninvasive or traditional), in the type of organism studied (plant or animal) and the molecular markers used [microsatellites or amplified fragment length polymorphisms (AFLPs)]. In these data sets, the estimated genotyping error rate ranges from 0.8% for microsatellite loci from bear tissues to 2.6% for AFLP loci from dwarf birch leaves. Main sources of errors were allelic dropouts for microsatellites and differences in peak intensities for AFLPs, but in both cases human factors were non-negligible error generators. Therefore, tracking genotyping errors and identifying their causes are necessary to clean up the data sets and validate the final results according to the precision required. In addition, we propose the outline of a protocol designed to limit and quantify genotyping errors at each step of the genotyping process. In particular, we recommend (i) several efficient precautions to prevent contaminations and technical artefacts; (ii) systematic use of blind samples and automation; (iii) experience and rigor for laboratory work and scoring; and (iv) systematic reporting of the error rate in population genetics studies.

Dynamics of a doped polymer at temperatures where the two-level system model of glasses fails: Study by single-molecule spectroscopy

We investigated the spectra of a large number of single tetra-tert-butylterrylene molecules embedded in an amorphous polyisobutylene matrix and analyzed the distributions of their linewidths (widths of single spectral peaks). The measurements were performed at 2, 4.5, and 7 K. This is a temperature region, where the standard two-level system (TLS) model of low-temperature glasses begins to fail. At T=2 K the temporal behavior (history of frequency jumps) of most of the measured spectra and their linewidth distributions were found to be consistent with the TLS model. At higher temperatures the main features of individual spectra (number of spectral peaks, temperature variation of peak widths, ratio of intensities of different peaks, etc.) still appear consistent with the predictions of this model. An increase of temperature leads mainly to the broadening of spectral peaks. A detailed analysis of the linewidth distributions reveals deviations from a standard TLS model at T=4.5 and 7 K. This difference is attributed to the influence of quasi-local low-frequency modes (LFM) of the amorphous matrix. By comparing the measured linewidth distributions with computer simulations, we quantitatively determined the LFM contribution to the single-molecule spectra in our dye-matrix system at different temperatures.

Measurement of methyl 13C-1H cross-correlation in uniformly 13C-, 15N-, labeled proteins.

An understanding of side chain motions in protein is of great interest since side chains often play an important role in protein folding and intermolecular interactions. A novel method for measuring the dynamics of methyl groups in uniformly 13C-, 15N-labeled proteins has been developed by our group. The method relies on the difference in peak intensities of 13C quartet components of methyl groups, in a spectrum recording the free evolution of 13C under proton coupling in a constant-time period. Cross-correlated relaxation rates between 13C-1H dipoles can be easily measured from the intensities of the multiplet components. The degree of the methyl restrictions (S(' 2)) can be estimated from the cross-correlated relaxation rate. The method is demonstrated on a sample of human fatty acid binding protein in the absence of fatty acid. We obtained relaxation data for 33 out of 46 residues having methyl groups in apo-IFABP. It has been found that the magnitude of the CSA tensor of spin 13C in a methyl group could be estimated from the intensities of the 13C multiplet components.

Physicochemical Properties of Starch in Extruded Rice Flours

ABSTRACTThe effects of extruding temperatures and subsequent drying conditions on X‐ray diffraction patterns (XRD) and differential scanning calorimetry (DSC) of long grain (LG) and short grain (SG) rice flours were investigated. The rice flours were extruded in a twin‐screw extruder at 70–120°C and 22% moisture, and either dried at room temperature, transferred to 4°C for 60 hr, or frozen and then dried at room temperature until the moisture was 10–11%. The dried materials were milled without the temperature increasing above 32°C. XRD studies were conducted on pellets made from extruded and milled flours with particle sizes of 149–248 μm; DSC studies were conducted from the same material. DSC studies showed that frozen materials retrograded more than the flours dried at room temperature. The LG and SG samples had two distinct XRD patterns. The LG gradually lost its A pattern at &gt;100°C, while acquiring V patterns at higher temperatures. SG gradually lost its A pattern at 100°C but stayed amorphous at the higher extruding temperatures. DSC analysis showed that retrograded flours did not produce any new XRD 2θ peaks, although a difference in 2θ peak intensities between the LG and SG rice flours was observed. DSC analysis may be very sensitive in detecting changes due to drying conditions, but XRD data showed gradual changes due to processing conditions. The gradual changes in XRD pattern and DSC data suggest that physicochemical properties of the extruded rice flours can be related to functional properties.

Structure and surface of TiNi human implants

The surface and the “bulk” structure of TiNi implants were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoemission spectroscopy (XPS), and scanning Auger microprobe analysis (AES). TiNi implants were compared with otherwise identically prepared non-implanted specimens, and sputter-cleaned and reoxidized samples. Non-implanted and implanted samples had essentially the same surface topography and microstructure. Ti, O, and C were the dominant elements detected on the surface. Trace amounts (∼1 at%) of Ni and Ca, N, Si, B, and S were also detected. Ti was present as TiO 2 on the surface, while nickel was present in metallic form. A significant difference in Ni peak intensity was observed when retrieved or non-implanted control samples (a very low nickel content) were compared with sputter-cleaned and reoxidized samples (well-detected nickel). It is evident that the method of passivation is crucial for nickel loosening. No major changes occurred in the TiNi samples bulk structure or in the surface oxide during the implantation periods investigated.

Myth: codeine is a powerful and effective analgesic.

Patients look to physicians not only to prevent and treat disease, but also to alleviate pain and suffering. Pain is the most common complaint among patients seen in the emergency department.1 A widely held belief is that codeine is a powerful and effective analgesic. The classic therapeutic regimen, endorsed by the American Society of Anesthesiologists Task Force on Pain Management, is to begin with nonopiate analgesia and to add opiate therapy if the level of pain control proves to be inadequate.2 The most common prepackaged combination therapy is codeine with acetaminophen (Tylenol #3 or #4).3 The underlying theory of this plan is that using 2 drugs with different mechanisms of action will, in essence, attack the problem from 2 sides. Unfortunately, studies have shown that this combination is at best only slightly more efficacious than nonopiate analgesia alone and results in a greatly increased number of adverse side effects. In a systematic literature review and meta-analysis of 29 published trials, de Craen and colleagues examined the change in both efficacy and safety when codeine was added to paracetamol (acetaminophen) for the relief of pain.4 Multiple reviewers were used to assess all studies, and 13 predefined methodologic criteria were applied to assess the quality of each trial. Pain intensity and relief were quantified through visual analog scales. In most studies, 60 mg of codeine was administered; the dosage of paracetamol ranged from 400 to 1,000 mg. Results of the pooled analysis of the 19 single-dose trials showed that adding codeine leads to an increase in analgesic effect of only 5%, as measured by the sum peak intensity difference, and produces similar results in peak painintensity difference, total pain relief, and peak pain relief. While the single-dose studies showed a similar incidence of side effects between the 2 groups (pooled rate ratio = 1.1, 95% confidence interval 0.8-1.4), multidose studies showed a significant increase in side effects when codeine was added (pooled rate ratio = 2.5, 95% confidence interval 1.5-3.5). Boreau et al reported similar findings from a randomized, double-blind, multicenter study in which they compared the use of acetaminophen (400 mg) plus codeine (25 mg) with aspirin (1000 mg) and with placebo in the treatment of acute migraine headache in 198 patients.5 Response was measured with a visual analog scale in which a patient was asked to mark the intensity of his or her pain on a 100-mm line where 0 is “no pain” and 100 is “worst possible pain.” Baseline pain levels ranged from 55.9 to 59.6. Two hours after treatment was administered, the mean pain scores were 36.6 and 39.3 for aspirin and for acetaminophen plus codeine, respectively, with a placebo value of 53.8. Side-effect profiles were similar in the 2 treatment arms of this study. Analgesic combinations with hydrocodone bitartrate appear to be more effective than those with codeine. Palangio et al performed a randomized, double-blind, multicenter study in which 429 patients were randomly assigned to receive either 1- or 2-tablet doses of a hydrocodone (7.5 mg) plus ibuprofen (200 mg) combination or a 2-tablet dose of a codeine (30 mg) plus acetaminophen (300 mg) combination.6 Patients who received the 2-tablet hydrocodone plus ibuprofen treatment reported greater daily pain relief than those who received either of the other 2 combinations. In addition, patients receiving codeine were more likely to stop therapy because of side effects. The myth that codeine is a potent and efficacious analgesic must be exposed so that clinicians can make more rational choices when managing and treating pain.

Dosimetric Characteristics of Natural Calcium Fluoride of Iran

Thermoluminescent characteristics of nine batches of fluorite (natural CaF2) from seven mines in Iran were studied for radiation protection dosimetry, some preliminary results of which are presented and discussed. The initial thermal treatment was optimised for cleaning the natural dose at 500(C for 24 h. All the batches, except two, showed the same glow curve structures with three prominent peaks of different intensities at approximately 120, 180 and 270(C (ß = 3(C.s-1). One batch from one mine showed a sensitivity about 8.7 times by peak area higher than that of TLD-100 (Harshaw) powder and about the same sensitivity as that of TLD-200, with a dose response linear up to 100 Gy. A thermal fading of 15% during the first day and 17% during a month reached negligible fading per month after a post-irradiation thermal treatment at 100(C for 20 min. The minimum measurable dose of this phosphor was determined to be 18 µGy.mg-1.

Non-destructive analysis of the conformational changes in human lens lipid and protein structures of the immature cataracts associated with glaucoma

Previous study has supposed a possible mechanism of exacerbating cataract formation in cataractous human lens capsules induced by hypertension or glaucoma. To clarify the glaucoma-induced cataract formation of the eyes lens, changes in the human lens lipid and protein structures of immature cataractous patients with or without glaucoma were investigated. Two normal lenses, ten immature cataractous lenses without any complication and four immature cataractous lenses with glaucoma were used after surgical operation. Each de-capsulated human lens sample was sliced with a number 15 surgical blade. The intact nuclear lens regions were used for non-destructive analysis. The lens lipid and protein structures, as well as compositions of these lens samples, were determined using a Fourier transform infrared (FTIR) microspectroscopy with second-derivative, de-convolution and curve-fitting methods. The results indicate that the IR spectrum of glaucomatous lenses appeared as a shoulder only at 2853 cm −1, thus the composition of the symmetric CH 2 stretching band at 2853 (2852) cm −1 decreased more significantly in glaucomatous lens to only one half of that in normal and immature cataractous lenses. The composition of the asymmetric CH 3 stretching band at 2965 cm −1 for normal lens decreases markedly from 32 to 20% for immature cataractous lenses with or without glaucoma. The compositional ratio of component at 2965 cm −1 to component at 2928 (2930) cm −1 for normal lenses was about 0.702, and that ratio for cataractous lenses without glaucoma was 0.382 but for glaucomatous lenses was 0.377. The maximum peak position of amide I band for IR spectra of the normal lens, immature cataractous lenses without complications or glaucomatous lenses appeared respectively at 1632, 1630 or 1622 cm −1, assigned to β sheet structure. A marked difference in peak intensity of amide I band for the normal lenses and immature cataractous human lenses with or without glaucoma was observed. The peak intensity ratio of amide I /amide II (1632/1545 cm −1) for normal lenses was in the range of 2.20–2.33, whereas in the spectra of immature cataractous lenses without glaucoma this ratio (1630/1545 cm −1) was 1.28–1.41 but was 1.04–1.13 for glaucomatous lens in the intensity ratio of 1622/1545 cm −1. The intensity of the glycogen bands in the wavenumber region 1135–1076 and 1069–1032 cm −1 was found to increase for the immature cataractous lenses with or without glaucoma, as compared with the normal ones. The peaks ranging from 1633 to 1610 cm −1 assigned to β-sheet structure also exhibited a pronounced compositional difference, particularly in glaucomatous lenses. The human lens lipid and protein secondary structures were more affected by glaucoma. Higher protein side chains and reduced lipid content contributed predominantly to the CH stretching vibrations of normal lens structure, whereas high lipid content and less protein side chains dominated the CH stretching vibrations of cataractous lenses with or without glaucoma. Decrease α-helix and random coil structures but enhanced β-sheet structure in the immature cataractous human lens induced by glaucoma might result from the formation of intermolecular hydrogen-bonding insoluble protein aggregates that modify the secondary structure of protein in lenses.

Structure and performance of soy hull carbon adsorbents as affected by pyrolysis temperature

AbstractSoy hulls were evaluated as a source of adsorbent carbon for vegetable oil processing. Soy hull carbon was prepared by burning ground soy hulls (&lt;100 mesh) at 300, 400, 500, or 700°C in a muffle furnace. The structure of the soy hull carbon was studied by scanning electron microscope (SEM), X‐ray diffraction (XRD), and Fourier‐transform infrared spectroscopy (FTIR). Crude soy oil was processed with the soy hull carbon products at 2% (w/w) in the laboratory under commercial bleaching conditions. Free fatty acids (FFA), peroxide value, phospholipid phosphorus (PLP), and lutein content of the treated samples were determined. SEM of the samples revealed particle size ranging from 1 to 2 mm. Increasing the pyrolysis temperature resulted in expansion and disruption of cellular structure. FTIR spectra of the carbon samples showed major differences in peak intensities at 3600 to 3200, 1600, and 1450 cm−1 due to pyrolysis temperature. XRD revealed a predominantly amorphous structure with increasing pyrolysis temperature, which also resulted in an increased alkaline surface. Soy hull carbon decreased the FFA content of oil samples compared to that of crude oil, with the exception of carbon that was prepared at 300°C (P&lt;0.05). A similar trend was observed in the adsorption of peroxides; however, no trends were observed in the adsorption of PLP or lutein. Higher pyrolysis temperature decreased randomness of the carbon and imparted a certain degree of structural order. This may be beneficial in providing physical access of the adsorbate molecule to the adsorbent surface.