Brain PET imaging optimization with time of flight and point spread function modelling

PurposeTo assess the influence of reconstruction algorithms and parameters on the PET image quality of brain phantoms in order to optimize reconstruction for clinical PET brain studies in a new generation PET/CT.MethodsThe 3D Hoffman phantom that simulates ¹⁸F-fluorodeoxyglucose (FDG) distribution was imaged in a Siemens Biograph mCT TrueV PET/CT with Time of Flight (TOF) and Point Spread Function (PSF) modelling. Contrast-to-Noise Ratio (CNR), contrast and noise were studied for different reconstruction models: OSEM, OSEM + TOF, OSEM + PSF and OSEM + PSF + TOF.The 2D multi-compartment Hoffman phantom was filled to simulate 4 different tracers' spatial distribution: FDG, ¹¹C-flumazenil (FMZ), ¹¹C-Methionine (MET) and 6-¹⁸F-fluoro-l-dopa (FDOPA). The best algorithm for each tracer was selected by visual inspection. The maximization of CNR determined the optimal parameters for each reconstruction.ResultsIn the 3D Hoffman phantom, both noise and contrast increased with increasing number of iterations and decreased with increasing FWHM. OSEM + PSF + TOF reconstruction was generally superior to other reconstruction models. Visual analysis of the 2D Hoffman brain phantom suggested that OSEM + PSF + TOF is the optimum algorithm for tracers with focal uptake, such as MET or FDOPA, and OSEM + TOF for tracers with diffuse cortical uptake (i.e. FDG and FMZ). Optimization of CNR demonstrated that OSEM + TOF reconstruction must be performed with 2 iterations and a filter FWHM of 3 mm, and OSEM + PSF + TOF reconstruction with 4 iterations and 1 mm FWHM filter.ConclusionsOptimization of reconstruction algorithm and parameters has been performed to take particular advantage of the last generation PET scanner, recommending specific settings for different brain PET radiotracers.     

Bayesian penalized-likelihood reconstruction algorithm suppresses edge artifacts in PET reconstruction based on point-spread-function

PurposeThe Bayesian penalized-likelihood reconstruction algorithm (BPL), Q.Clear, uses relative difference penalty as a regularization function to control image noise and the degree of edge-preservation in PET images. The present study aimed to determine the effects of suppression on edge artifacts due to point-spread-function (PSF) correction using a Q.Clear.MethodsSpheres of a cylindrical phantom contained a background of 5.3 kBq/mL of [¹⁸F]FDG and sphere-to-background ratios (SBR) of 16, 8, 4 and 2. The background also contained water and spheres containing 21.2 kBq/mL of [¹⁸F]FDG as non-background. All data were acquired using a Discovery PET/CT 710 and were reconstructed using three-dimensional ordered-subset expectation maximization with time-of-flight (TOF) and PSF correction (3D-OSEM), and Q.Clear with TOF (BPL). We investigated β-values of 200–800 using BPL. The PET images were analyzed using visual assessment and profile curves, edge variability and contrast recovery coefficients were measured.ResultsThe 38- and 27-mm spheres were surrounded by higher radioactivity concentration when reconstructed with 3D-OSEM as opposed to BPL, which suppressed edge artifacts. Images of 10-mm spheres had sharper overshoot at high SBR and non-background when reconstructed with BPL. Although contrast recovery coefficients of 10-mm spheres in BPL decreased as a function of increasing β, higher penalty parameter decreased the overshoot.ConclusionsBPL is a feasible method for the suppression of edge artifacts of PSF correction, although this depends on SBR and sphere size. Overshoot associated with BPL caused overestimation in small spheres at high SBR. Higher penalty parameter in BPL can suppress overshoot more effectively.     

β2-microglobulin is overexpressed in buccal cells of elderly and correlated with expression of p16 and inflammatory genes

β2M (Beta 2 microglobulin) is a small protein that is found in all nucleated cells, previous finding showed that its levels increased in the serum of the elderly. Buccal cell samples are none invasive approach for assessing the expression of target genes. There was rationality to assess the expression of β2M in buccal cells of people of a different group of ages. Indeed, the expression of β2M increased significantly with fold change 3.40, 4.80, 6.60^**, 8.20^*** and 12.04^*** for the group of age 18–25 years, 26–35 years, 36–45 years, 46–55 years, and 56–70 years respectively. The same observation was seen with markers of biological aging (p16^INK4a) with fold change 3.19, 3.90, 4.80*, 8.50^*** and 12.40^*** for the group of age 18–25 years, 26–35 years, 36–45 years, 46–55 years, and 56–70 years respectively. As expected, there was an increase in the inflammatory genes (IL-1 β and IL-6) expression in the elderly. Moreover, there was a direct significant correlation (r = 90, p < 0.001) between β2M expression and age (years), and the same direct significant correlation between p16^INK4a expression and age (years) was also seen (r = 90, p < 0.001). In addition, a direct correlation between β2M and p16^INK4a was also seen (r = 0.8.3, p < 0.001), there was also direct correlation between β2M and IL-1 β and IL-6 with (r = 0.5, p < 0.001; r = 0.68, p < 0.001) respectively. This evidence showed that β2M increased in buccal cells of the elderly compared to younger, and thereby buccal cells can be exploited to assess biological aging by measuring β2M levels, however, large sample size and using another assessing method such as β2M protein levels should be performed to confirm the results.     

Ethanol production by Escherichia coli from detoxified lignocellulosic teak wood hydrolysates with high concentration of phenolic compounds

Teak wood residues were subjected to thermochemical pretreatment, enzymatic saccharification, and detoxification to obtain syrups with a high concentration of fermentable sugars for ethanol production with the ethanologenic Escherichia coli strain MS04. Teak is a hardwood, and thus a robust deconstructive pretreatment was applied followed by enzymatic saccharification. The resulting syrup contained 60 g l^–1 glucose, 18 g l^–1 xylose, 6 g l^–1 acetate, less than 0.1 g l^–1 of total furans, and 12 g l^–1 of soluble phenolic compounds (SPCs). This concentration of SPC is toxic to E. coli, and thus two detoxification strategies were assayed: (1) treatment with Coriolopsis gallica laccase followed by addition of activated carbon and (2) overliming with Ca(OH)₂. These reduced the phenolic compounds by 40% and 76%, respectively. The detoxified syrups were centrifuged and fermented with E. coli MS04. Cultivation with the overlimed hydrolysate showed a 60% higher volumetric productivity (0.45 g_ETOH l^–1 hr^–1). The bioethanol/sugar yield was over 90% in both strategies.     

Transactivation of ErbB Family of Receptor Tyrosine Kinases Is Inhibited by Angiotensin-(1-7) via Its Mas Receptor

Transactivation of the epidermal growth factor receptor (EGFR or ErbB) family members, namely EGFR and ErbB2, appears important in the development of diabetes-induced vascular dysfunction. Angiotensin-(1–7) [Ang-(1–7)] can prevent the development of hyperglycemia-induced vascular complications partly through inhibiting EGFR transactivation. Here, we investigated whether Ang-(1–7) can inhibit transactivation of ErbB2 as well as other ErbB receptors in vivo and in vitro. Streptozotocin-induced diabetic rats were chronically treated with Ang-(1–7) or AG825, a selective ErbB2 inhibitor, for 4 weeks and mechanistic studies performed in the isolated mesenteric vasculature bed as well as in cultured vascular smooth muscle cells (VSMCs). Ang-(1–7) or AG825 treatment inhibited diabetes-induced phosphorylation of ErbB2 receptor at tyrosine residues Y1221/22, Y1248, Y877, as well as downstream signaling via ERK1/2, p38 MAPK, ROCK, eNOS and IkB-α in the mesenteric vascular bed. In VSMCs cultured in high glucose (25 mM), Ang-(1–7) inhibited src-dependent ErbB2 transactivation that was opposed by the selective Mas receptor antagonist, D-Pro⁷-Ang-(1–7). Ang-(1–7) via Mas receptor also inhibited both Angiotensin II- and noradrenaline/norephinephrine-induced transactivation of ErbB2 and/or EGFR receptors. Further, hyperglycemia-induced transactivation of ErbB3 and ErbB4 receptors could be attenuated by Ang-(1–7) that could be prevented by D-Pro⁷-Ang-(1–7) in VSMC. These data suggest that Ang-(1–7) via its Mas receptor acts as a pan-ErbB inhibitor and might represent a novel general mechanism by which Ang-(1–7) exerts its beneficial effects in many disease states including diabetes-induced vascular complications.     

Determination of base and backbone contributions to the thermodynamics of premelting and melting transitions in B DNA

In previous papers of this series the temperature-dependent Raman spectra of poly(dA)·poly(dT) and poly(dA–dT)·poly(dA–dT) were used to characterize structurally the melting and premelting transitions in DNAs containing consecutive A·T and alternating A·T/T·A base pairs. Here, we describe procedures for obtaining thermodynamic parameters from the Raman data. The method exploits base-specific and backbone-specific Raman markers to determine separate thermodynamic contributions of A, T and deoxyribosyl-phosphate moieties to premelting and melting transitions. Key findings include the following: (i) Both poly(dA)·poly(dT) and poly(dA–dT)· poly(dA–dT) exhibit robust premelting transitions, due predominantly to backbone conformational changes. (ii) The significant van’t Hoff premelting enthalpies of poly(dA)·poly(dT) [ΔH_vH^pm = 18.0 ± 1.6 kcal·mol^–1 (kilocalories per mole cooperative unit)] and poly(dA–dT)·poly(dA–dT) (ΔH_vH^pm = 13.4 ± 2.5 kcal·mol^–1) differ by an amount (~4.6 kcal·mol^–1) estimated as the contribution from three-centered inter-base hydrogen bonding in (dA)_n·(dT)_n tracts. (iii) The overall stacking free energy of poly(dA)· poly(dT) [–6.88 kcal·mol_bp^–1 (kilocalories per mole base pair)] is greater than that of poly(dA–dT)· poly(dA–dT) (–6.31 kcal·mol_bp^–1). (iv) The difference between stacking free energies of A and T is significant in poly(dA)·poly(dT) (ΔΔG_st = 0.8 ± 0.3 kcal· mol_bp^–1), but marginal in poly(dA–dT)·poly(dA–dT) (ΔΔG_st = 0.3 ± 0.3 kcal·mol_bp^–1). (v) In poly(dA)· poly(dT), the van’t Hoff parameters for melting of A (ΔH_vH^A = 407 ± 23 kcal·mol^–1, ΔS_vH^A = 1166 ± 67 cal·°K^–1·mol^–1, ΔG_vH(25°C)^A = 60.0 ± 3.2 kcal·mol^–1) are clearly distinguished from those of T (ΔH_vH^T = 185 ± 38 kcal·mol^–1, ΔS_vH^T = 516 ± 109 cal·°K^–1·mol^–1, ΔG_vH(25°C)^T = 27.1 ± 5.5 kcal·mol^–1). (vi) Similar relative differences are observed in poly(dA–dT)· poly(dA–dT) (ΔH_vH^A = 333 ± 54 kcal·mol^–1, ΔS_vH^A = 961 ± 157 cal·°K^–1·mol^–1, ΔG_vH(25°C)^A = 45.0 ± 7.6 kcal· mol^–1; ΔH_vH^T = 213 ± 30 kcal·mol^–1, ΔS_vH^T = 617 ± 86 cal·°K^–1·mol^–1, ΔG_vH(25°C)^T = 29.3 ± 4.9 kcal·mol^–1). The methodology employed here distinguishes thermodynamic contributions of base stacking, base pairing and backbone conformational ordering in the molecular mechanism of double-helical B DNA formation.     

High-Resolution Echo-Planar Spectroscopic Imaging of the Human Calf

Background

This study exploits the speed benefits of echo-planar spectroscopic imaging (EPSI) to acquire lipid spectra of skeletal muscle. The main purpose was to develop a high-resolution EPSI technique for clinical MR scanner, to visualise the bulk magnetic susceptibility (BMS) shifts of extra-myocellular lipid (EMCL) spectral lines, and to investigate the feasibility of this method for the assessment of intra-myocellular (IMCL) lipids.

Methods

The study group consisted of six healthy volunteers. A two dimensional EPSI sequence with point-resolved spectroscopy (PRESS) spatial localization was implemented on a 3T clinical MR scanner. Measurements were performed by means of 64×64 spatial matrix and nominal voxel size 3×3×15 mm³. The total net measurement time was 3 min 12 sec for non-water-suppressed (1 acquisition) and 12 min 48 sec for water-suppressed scans (4 acquisitions).

Results

Spectra of the human calf had a very good signal-to-noise ratio and linewidths sufficient to differentiate IMCL resonances from EMCL. The use of a large spatial matrix reduces inter-voxel signal contamination of the strong EMCL signals. Small voxels enabled visualisation of the methylene EMCL spectral line splitting and their BMS shifts up to 0.5 ppm relative to the correspondent IMCL line. The mean soleus muscle IMCL content of our six volunteers was 0.30±0.10 vol% (range 0.18–0.46) or 3.6±1.2 mmol/kg wet weight (range: 2.1–5.4).

Conclusion

This study demonstrates that high-spatial resolution PRESS EPSI of the muscle lipids is feasible on standard clinical scanners.     

Two new species of Yushania (Poaceae: Bambusoideae) from South China,with a taxonomic revision of related species

Two new species of Yushania (Poaceae, Bambusoideae, Arundinarieae) are described and illustrated from Hunan, China. Yushania longshanensis D.Z. Li & X.Y. Ye is distinguished from related species (Y. confusa, Y. angustifolia and Y. pachyclada) by having a thinner culm (0.2–0.3 cm in diameter), glabrous sheath scar, no oral setae, a large glabrous leaf blade (10–20 × 0.9–1.3 cm) and 3–4 pairs of secondary veins. Yushania stoloniforma D.Z. Li & X.Y. Ye has a distinctive scrambling habit, which differs from its putative close allies. Both of these two new species have a solitary branch at the basal nodes and can be assigned to Yushania sect. Yushania based on morphological features. Additionally, we treated Yushania gigantea T.P. Yi & L. Yang as a new synonym of Y. elevata T.P. Yi and renamed Y. microphylla T.P. Yi & L. Yang as Y. weiningensis D.Z. Li & X.Y. Ye.     

3D image-based dosimetry for Yttrium-90 radioembolization of hepatocellular carcinoma: Impact of imaging method on absorbed dose estimates

BackgroundTo improve therapy outcome of Yttrium-90 selective internal radiation therapy (⁹⁰Y SIRT), patient-specific post-therapeutic dosimetry is required. For this purpose, various dosimetric approaches based on different available imaging data have been reported. The aim of this work was to compare post-therapeutic 3D absorbed dose images using Technetium-99m (^99mTc) MAA SPECT/CT, Yttrium-90 (⁹⁰Y) bremsstrahlung (BRS) SPECT/CT, and ⁹⁰Y PET/CT.MethodsTen SIRTs of nine patients with unresectable hepatocellular carcinoma (HCC) were investigated. The ^99mTc SPECT/CT data, obtained from ^99mTc-MAA-based treatment simulation prior to ⁹⁰Y SIRT, were scaled with the administered ⁹⁰Y therapy activity. 3D absorbed dose images were generated by dose kernel convolution with scaled ^99mTc/⁹⁰Y SPECT/CT, ⁹⁰Y BRS SPECT/CT, and ⁹⁰Y PET/CT data of each patient. Absorbed dose estimates in tumor and healthy liver tissue obtained using the two SPECT/CT methods were compared against ⁹⁰Y PET/CT.ResultsThe percentage deviation of tumor absorbed dose estimates from ⁹⁰Y PET/CT values was on average −2 ± 18% for scaled ^99mTc/⁹⁰Y SPECT/CT, whereas estimates from ⁹⁰Y BRS SPECT/CT differed on average by −50 ± 13%. For healthy liver absorbed dose estimates, all three imaging methods revealed comparable values.ConclusionThe quantification capabilities of the imaging data influence ⁹⁰Y SIRT tumor dosimetry, while healthy liver absorbed dose values were comparable for all investigated imaging data. When no ⁹⁰Y PET/CT image data are available, the proposed scaled ^99mTc/⁹⁰Y SPECT/CT dosimetry method was found to be more appropriate for HCC tumor dosimetry than ⁹⁰Y BRS SPECT/CT based dosimetry.     

Quantification of image quality of intra-fractional cone-beam computed tomography for arc irradiation with various imaging condition

Background3-dimensional intra-cone beam computed tomography (intra-CBCT ) could be a potentially powerful tool for use with arc irradiation such as volumetric modulated arc therapy. The aim of the study was to evaluate the image quality of intra-cone beam computed tomography (intra-CBCT ) for arc irradiation with various imaging condition.Materials and methodsTwo types of intra-CBCT imaging techniques were evaluated — intra-fractional CBCT with flattening filtered (FF) beam (intra-FF CBCT ) and that with flattening filter free (FFF) beam (intra-FFF CBCT ). For the intra-MV beams, four different field sizes (2 cm × 2 cm, 5 cm × 5 cm, 10 cm × 10 cm, and 20 cm × 20 cm) were used with dose rates of 500 MU/min and 1600 MU/min, for 6 MV FF and 6 MV FFF, respectively. For all image acquisitions, two rotation angles (full-arc and half-arc) were investigated. Thereafter, the linearity, contrast-to-noise ratio (CNR), and uniformity index (UI) of intra-CBCT image were compared with those of conventional CBCT image.ResultsAll acquisition conditions had good linearity of the CT value (R² > 0.99). For CNR, the change rates from conventional CBCT ranged from 0.6–33.7% for a 2 cm × 2 cm beam, whereas that for a 20 cm × 20 cm beam ranged from 62.7–82.3%. Similarly, the UI increased from 1.5% to 7.0% as the field size increased.ConclusionQuality of intra-CBCT image was affected by the field size and acquisition angle. Image quality of intra-CBCT was worse than that of conventional CBCT, but it was better under a smaller field and wider correction angle and would be acceptable for clinical use.     

Cardio-Respiratory Reference Data in 4631 Healthy Men and Women 20-90 Years: The HUNT 3 Fitness Study

Purpose

To provide a large reference material on key cardio-respiratory variables in a healthy population of Norwegian men and women aged 20–90 years.

Methods

Sub maximal and peak levels of cardio-respiratory variables were measured using cardiopulmonary exercise testing during treadmill running.

Results

The highest peak ventilation among men (141.9±24.5 L·min⁻¹) and women (92.0±16.5 L·min⁻¹) was observed in the youngest age group (20–29 years, sex differences p<0.001) with an average 7% reduction per decade. The highest tidal volumes were observed in the 30–39 and 40–49 year age groups among men (2.94±0.46 L) and women (2.06±0.32 L) (sex differences p<0.001), with a subsequent average 6% reduction per decade. Ventilatory threshold and respiratory compensation point were observed at approximately 77% and 87% of peak oxygen uptake (VO_2peak) among men and women, respectively. The best ventilatory efficiency (EqVCO_2Than) was observed in the youngest age group (20–29 years) in both men (26.2±2.8) and woman (27.5±2.7) (sex differences p<0.001) with an average 3% deterioration in ventilatory efficiency per decade.

Conclusion

This is the largest European reference material of cardio-respiratory variables in healthy men and women aged 20–90 years, establishing normal values for, and associations between key cardio-respiratory parameters. This will be useful in clinical decision making when evaluating cardiopulmonary health in similar populations.     

Accuracy of [18F]FDG PET/MRI for the Detection of Liver Metastases

Background

The aim of this study was to compare the diagnostic accuracy of [¹⁸F]FDG-PET/MRI with PET/CT for the detection of liver metastases.

Methods

32 patients with solid malignancies underwent [¹⁸F]FDG-PET/CT and subsequent PET/MRI of the liver. Two readers assessed both datasets regarding lesion characterization (benign, indeterminate, malignant), conspicuity and diagnostic confidence. An imaging follow-up (mean interval: 185±92 days) and/-or histopathological specimen served as standards of reference. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for both modalities. Accuracy was determined by calculating the area under the receiver operating characteristic (ROC) curve. Values of conspicuity and diagnostic confidence were compared using Wilcoxon-signed-rank test.

Results

The standard of reference revealed 113 liver lesions in 26 patients (malignant: n = 45; benign: n = 68). For PET/MRI a higher accuracy (PET/CT: 82.4%; PET/MRI: 96.1%; p<0.001) as well as sensitivity (67.8% vs. 92.2%, p<0.01) and NPV (82.0% vs. 95.1%, p<0.05) were observed. PET/MRI offered higher lesion conspicuity (PET/CT: 2.0±1.1 [median: 2; range 0–3]; PET/MRI: 2.8±0.5 [median: 3; range 0–3]; p<0.001) and diagnostic confidence (PET/CT: 2.0±0.8 [median: 2; range: 1–3]; PET/MRI 2.6±0.6 [median: 3; range: 1–3]; p<0.001). Furthermore, PET/MRI enabled the detection of additional PET-negative metastases (reader 1: 10; reader 2: 12).

Conclusions

PET/MRI offers higher diagnostic accuracy compared to PET/CT for the detection of liver metastases.     

Field Evaluation of Two Rapid Diagnostic Tests for Neisseria meningitidis Serogroup A during the 2006 Outbreak in Niger

The Pastorex^® (BioRad) rapid agglutination test is one of the main rapid diagnostic tests (RDTs) for meningococcal disease currently in use in the “meningitis belt”. Earlier evaluations, performed after heating and centrifugation of cerebrospinal fluid (CSF) samples, under good laboratory conditions, showed high sensitivity and specificity. However, during an epidemic, the test may be used without prior sample preparation. Recently a new, easy-to-use dipstick RDT for meningococcal disease detection on CSF was developed by the Centre de Recherche Médicale et Sanitaire in Niger and the Pasteur Institute in France. We estimate diagnostic accuracy in the field during the 2006 outbreak of Neisseria meningitidis serogroup A in Maradi, Niger, for the dipstick RDT and Pastorex^® on unprepared CSF, (a) by comparing each test''s sensitivity and specificity with previously reported values; and (b) by comparing results for each test on paired samples, using McNemar''s test. We also (c) estimate diagnostic accuracy of the dipstick RDT on diluted whole blood. We tested unprepared CSF and diluted whole blood from 126 patients with suspected meningococcal disease presenting at four health posts. (a) Pastorex^® sensitivity (69%; 95%CI 57–79) was significantly lower than found previously for prepared CSF samples [87% (81–91); or 88% (85–91)], as was specificity [81% (95%CI 68–91) vs 93% (90–95); or 93% (87–96)]. Sensitivity of the dipstick RDT [89% (95%CI 80–95)] was similar to previously reported values for ideal laboratory conditions [89% (84–93) and 94% (90–96)]. Specificity, at 62% (95%CI 48–75), was significantly lower than found previously [94% (92–96) and 97% (94–99)]. (b) McNemar''s test for the dipstick RDT vs Pastorex^® was statistically significant (p<0.001). (c) The dipstick RDT did not perform satisfactorily on diluted whole blood (sensitivity 73%; specificity 57%).Sensitivity and specificity of Pastorex^® without prior CSF preparation were poorer than previously reported results from prepared samples; therefore we caution against using this test during an epidemic if sample preparation is not possible. For the dipstick RDT, sensitivity was similar to, while specificity was not as high as previously reported during a more stable context. Further studies are needed to evaluate its field performance, especially for different populations and other serogroups.     

Hydropathic analysis of the free energy differences in anthracycline antibiotic binding to DNA

Molecular models of six anthracycline antibiotics and their complexes with 32 distinct DNA octamer sequences were created and analyzed using HINT (Hydropathic INTeractions) to describe binding. The averaged binding scores were then used to calculate the free energies of binding for comparison with experimentally determined values. In parsing our results based on specific functional groups of doxorubicin, our calculations predict a free energy contribution of –3.6 ± 1.1 kcal mol^–1 (experimental –2.5 ± 0.5 kcal mol^–1) from the groove binding daunosamine sugar. The net energetic contribution of removing the hydroxyl at position C9 is –0.7 ± 0.7 kcal mol^–1 (–1.1 ± 0.5 kcal mol^–1). The energetic contribution of the 3′ amino group in the daunosamine sugar (when replaced with a hydroxyl group) is –3.7 ± 1.1 kcal mol^–1 (–0.7 ± 0.5 kcal mol^–1). We propose that this large discrepancy may be due to uncertainty in the exact protonation state of the amine. The energetic contribution of the hydroxyl group at C14 is +0.4 ± 0.6 kcal mol^–1 (–0.9 ± 0.5 kcal mol^–1), largely due to unfavorable hydrophobic interactions between the hydroxyl oxygen and the methylene groups of the phosphate backbone of the DNA. Also, there appears to be considerable conformational uncertainty in this region. This computational procedure calibrates our methodology for future analyses where experimental data are unavailable.     

The characterization and localization of frog skin cholinesterase

Frog skin cholinesterase is largely of the serum (pseudocholinesterase) type. For whole skin, the activity at 10^–1 AcChCl is 4.9 µl./mg. N/hr. Tela subcutanea isolated by dissection exhibits an activity of 65 µl./mg. N/hr. at 10^–1 AcChCl. Since about one-tenth of the nitrogen of the skin is located in the tela subcutanea, it is estimated that more than 90 per cent of the enzyme is associated with this tissue layer.     

Smoking and Subclinical ILD in RA versus the Multi-Ethnic Study of Atherosclerosis

A population-based cohort showed an association between cigarette smoking and subclinical parenchymal lung disease defined as regions of increased computed tomography (CT) lung densitometry. This technique has not been applied to the rheumatoid arthritis (RA) population where associated ILD is highly prevalent. The association between cumulative cigarette smoking and volume of areas of high attenuation (HAA: >-600 and <-250 Hounsfield Units) on full inspiratory CT was compared in 172 RA participants and 3,969 controls in a general population sample. Multivariable regression models were used to adjust for demography, anthropometrics, percent emphysema, and CT parameters. The mean cumulative cigarette smoking exposure was 25 (IQR 10–42) and 15(IQR 5–31) pack-years for the RA and non-RA cohorts, respectively. Mean HAA was 153(±57) cm³ and 129(±50) cm³ in the RA and non-RA cohorts, respectively. Each 10 cigarette pack-year increment was associated with a higher HAA by 0.03% (95% CI, 0.007–0.05%) in RA patients and by 0.008% (95% CI, 0.003–0.01%) in those without RA (interaction p = 0.001). Cigarette smoking was associated with higher lung attenuation; with a magnitude of association more pronounced in those with RA than in the general population. These data suggest that cigarette smoking may be a more potent ILD risk factor for RA patients than in the general population.     

Superoxide radical production and performance index of Photosystem II in leaves from magnetoprimed soybean seeds

Priming of soybean seeds with static magnetic field exposure of 200 mT (1 h) and 150 mT (1 h) resulted in plants with enhanced performance index (PI). The three components of PI i.e the density of reaction centers in the chlorophyll bed (RC/ABS), exciton trapped per photon absorbed (φpo) and efficiency with which a trapped exciton can move in electron transport chain (Ψo) were found to be 17%, 27%  and 16% higher, respectively in leaves from 200 mT (1h) treated compared to untreated seeds.  EPR spectrum of  O₂^{. –} - PBN  adduct revealed that the O₂^{. –} radical level was lower by 16% in the leaves of plants that emerged from magnetic field treatment. Our study revealed that magnetoprimed seeds have a long lasting stimulatory effect on plants as reduced superoxide production and higher performance index contributed to higher efficiency of light harvesting that consequently increased biomass in plants from treated plants.     

Pyrrole-imidazole hairpin polyamides with high affinity at 5'-CGCG-3' DNA sequence; influence of cytosine methylation on binding

To investigate the binding of 5′–CpG–3′ sequences by small molecules, two pyrrole (Py)–imidazole (Im) hairpin polyamides, PyImPyIm–γ–PyImPyIm–β–Dp (1) and PyIm–β–Im–γ–PyIm–β–Im–β–Dp (2), which recognize the sequence 5′–CGCG–3′, were synthesized. The binding affinities of the 5′–CGCG–3′ sequence to the Py–Im hairpin polyamides were measured by surface plasmon resonance (SPR) analysis. SPR data revealed that dissociation equilibrium constants (K_d) of polyamides 1 and 2 were 1.1 (± 0.3) × 10^–6 M and 1.7 (± 0.4) × 10^–8 M, respectively. Polyamide 2 possesses great binding affinity for this sequence, 65-fold higher than polyamide 1. Moreover, when all cytosines in 5′–CpGpCpG–3′ were replaced with 5-methylcytosines (^mCs), the K_d value of polyamide 2 increased to 5.8 (± 0.7) × 10^–9 (M), which indicated about 3-fold higher binding than the unmethylated 5′–CGCG–3′ sequence. These results suggest that polyamide 2 would be suitable to target CpG-rich sequences in the genome.     

Ethanol Production from Colpomenia sinuosa by an Alginate Fermentation Strain Meyerozyma guilliermondii

With the consumption of energy and the spread of COVID-19, the demand for ethanol production is increasing in the world. The industrial ethanol fermentation microbes cannot metabolize the alginate component of macro algae, which affects the ethanol yield. In this research, the ethanol production process from macro algae by an alginate fermentation yeast Meyerozyma guilliermondii, especially the pretreatment process of Colpomenia sinuosa, was studied. At the same time, the experimental design of Box-Behnken was carried out to achieve the optimum fermentation performance. The concentration of KH₂PO₄ (A: 2–6 g.L⁻¹), pH (B: 4–7), reaction time (C: 60–120 h) and temperature (D: 24–34 °C) were variable input parameters. During the ethanol production process, the algae powder was firstly mixed with water at 90 °C for 0.5 h. Later the fermentation culture medium was prepared and then it was fermented by the yeast Meyerozyma guilliermondii to produce ethanol. And the optimal fermentation parameters were as follows: fermentation temperature of 28 °C, KH₂PO₄ dosage of 4.7 g.L⁻¹, initial pH of 6, and fermentation time of 99 h. The ethanol yield reached 0.268 g.g⁻¹ (ethanol to algae), close to the predicted value of model. The generation of alginate lyase during the fermentation of algae was also examined. The highest alginate lyase activity reached 46.42 U.mL⁻¹.     

Mass Change of Glaciers in Muztag Ata–Kongur Tagh,Eastern Pamir,China from 1971/76 to 2013/14 as Derived from Remote Sensing Data

The assessment of glacier mass budget is crucial for assessing water reserves stored in glaciers. Derived glacier mass changes in the Muztag Ata and Kongur Tagh (MAKT) region in the eastern Pamir, northwestern China, is helpful in improving our knowledge of the dynamics of glaciers under a changing climate in High Mountain Asia. Here, glacier area and mass changes derived from remote sensing data are investigated for the period 1971/76–2013/14 for glaciers in MAKT. We have used ASTER images (2013/14), Cartosat-1 (2014) and Landsat, SRTM (Shuttle Radar Terrain Mission) digital elevation model (DEM) (2000), topographic maps (1971/76) and the first and second Chinese glacier inventories (CGIs). Our results indicated that the glacier area of MAKT decreased from 1018.3 ± 12.99 km² in 1971/76 to 999.2 ± 31.22 km² in 2014 (–1.9 ± 0.2%). Weak area shrinkage of glaciers by 2.5 ± 0.5 km² (0.2 ± 0.1%) happened after 2000 and the period 2009–2014 even saw a slight expansion by 0.5 ± 0.1 km² (0.1 ± 0.0%). The glaciers in this region have experienced an overall loss of –6.99 ± 0.80 km³ in ice volume or –0.15 ± 0.12 m water equivalent (w.e.) a^–1 from 1971/76 to 2013/14. The mass budget of MAKT was –0.19 ± 0.19 m w.e. a⁻¹ for the period ~1971/76–1999 and –0.14 ± 0.24 m w.e. a⁻¹ during 1999–2013/2014. Similar to previous studies, there has been little mass change in the Pamir over recent decades despite such uncertainties. Glacier mass change showed spatial and temporal heterogeneity, with strong mass loss on debris-covered glaciers with an average of –0.32 ± 0.12 m w.e. a⁻¹ from the 1970s to 2013/14.