Polyhydroxyalkanoates (PHAs) are a unique class of polyesters especially due to their chemical diversity imparted by their side-chain substituent that provides a handle to tune their properties, such ...as their thermal, mechanical and (bio)degradability signature. Here, we report that some functional PHAs, namely PBPL
FG
s (FG = functional group), were synthesized by the controlled stereoselective ring-opening polymerization (ROP) of
racemic
4-substituted-β-propiolactones, namely
rac
-BPL
CH
2
ZPh
s with Z = O, S, CH
2
OCH
2
, catalyzed by diamino- or amino-alkoxy-bis(phenolate) yttrium amido complexes (
1a-1g
) in the presence of isopropanol. Unprecedented syndio-enriched (
P
r
up to 0.87) PBPL
CH
2
ZPh
s of high molar mass (
M
n,NMR
up to 86 400 g mol
−1
,
M
< 1.23) were thus typically prepared under mild operating conditions (toluene, 20 °C). Catalyst systems with smaller "uncrowded" Me or Cl
ortho
-substituents installed on the yttrium phenolate ligands (
1a-1c
) typically revealed less active than those with larger bulkier
t
Bu or CMe
2
Ph groups (
1d-1g
), regardless of the monomer (TOF
1a-1c
= 0.48-15 h
−1
, TOF
1d-1g
= 450-1840 h
−1
). Irrespective of the catalyst system, exchanging oxygen with sulphur in BPL
CH
2
ZPh
s, with Z = O, S, did not affect the stereochemistry, always affording syndiotactic PBPL
CH
2
ZPh
s. On the other hand, either atactic or syndiotactic PBPL
CH
2
CH
2
OCH
2
Ph
s were formed upon tuning the catalyst from
1a-1c
or
1d-1g
, respectively. The intimate relationship, through "non-covalent" interactions, between the chemical nature of the exocyclic functional side-group on the β-lactone and the stereoelectronic tuning arising from the phenolate ligand
ortho
-substituents within the yttrium coordination sphere, modulated the stereocontrol of the ROP. The thermal behavior of these original functional PHAs depended closely on their side-chain substituent (
T
onset
d
= 226 to 272 °C;
T
g
= −15 to +40 °C).
Polyhydroxyalkanoates (PHAs) are a unique class of polyesters especially due to their chemical diversity imparted by their side-chain substituent that provides a handle to tune their properties, such as their thermal, mechanical and (bio)degradability signature.
Stereoselective metal‐mediated ring‐opening polymerization of chiral cyclic esters is a powerful tool to access highly stereoregular polyesters. Not only syndiotactic and isotactic homopolymers can ...now be efficiently produced from racemic mixtures of these monomers, but also original copoly(hydroxyalkanoate)s with gradient or alternated patterns prepared from mixtures of chemically different, oppositely configurated enantiopure monomers. Some recent major achievements in that growing field are reviewed, with an emphasis on stereocontrol factors and mechanisms. For more information, see the Minireview by J.‐F. Carpentier, S. M. Guillaume et al. on page 128 ff.
Epilepsy is a chronic brain disorder which manifests as recurrent seizures. Electroencephalogram (EEG) signals are generally analyzed to study the characteristics of epileptic seizures. In this work, ...we propose a method for the automated classification of EEG signals into normal, interictal and ictal classes using Continuous Wavelet Transform (CWT), Higher Order Spectra (HOS) and textures. First the CWT plot was obtained for the EEG signals and then the HOS and texture features were extracted from these plots. Then the statistically significant features were fed to four classifiers namely Decision Tree (DT), K-Nearest Neighbor (KNN), Probabilistic Neural Network (PNN) and Support Vector Machine (SVM) to select the best classifier. We observed that the SVM classifier with Radial Basis Function (RBF) kernel function yielded the best results with an average accuracy of 96%, average sensitivity of 96.9% and average specificity of 97% for 23.6 s duration of EEG data. Our proposed technique can be used as an automatic seizure monitoring software. It can also assist the doctors to cross check the efficacy of their prescribed drugs.
Adsorptive studies were carried out on Di-ethyl phthalate (DEP) removal from aqueous phase onto activated carbon. Batch sorption studies were performed and the results revealed that activated carbon ...demonstrated ability to adsorb DEP. Influence of varying experimental conditions such as DEP concentration, pH of aqueous solution, and dosage of adsorbent were investigated on the adsorption process. Sorption interaction of DEP onto activated carbon obeyed the pseudo second order rate equation. Experimental data showed good fit with both the Langmuir and Freundlich adsorption isotherm models. DEP sorption was found to be dependent on the aqueous phase pH and the uptake was observed to be greater at acidic pH.
The soils of Indian Black Cotton are well-known examples of Expansive soils, which display significant swelling and shrinkage in response to changes in moisture content. The distressing cyclical ...swelling and shrinking of soils under moisture fluctuations lead to serious failures. Stabilization of soil can be used to improve it in order to get around this. An agricultural industrial waste called rice husk ash is created when rice husk, a byproduct of paddy milling, is burned. In delta regions, it is widely distributed. It is a pozzolanic material that is widely distributed in India and has potential use in a number of geotechnical areas. In this stabilisation process, black cotton soil is mixed with RHA-lime and various percentages of cementitious material, particularly lime. Tests such as plasticity, compaction, swell, and CBR were also conducted with different water contents of OMCs (such as OMC + 2% water content and OMC + 5% water content). From the test findings, it can be concluded that adding lime reduces flexibility and increases strength. With the addition of RHA and lime, expansive soil gets higher CBR values at varied water contents more than 50% for dosages of 10% lime + 20% RHA and 10% lime + 30% RHA. The expansive soil becomes non-plastic, non-swelling, and has increased strengths, making it suitable for use as a building material for roads.
Objective:
To evaluate the efficacy of cognitive-behavioral interventions (CBIs) for improving the mental health and immune functioning of people living with HIV (PLWH).
Design:
Comprehensive ...searches of electronic databases from 1988 to 2005, hand searches of journals, reference lists of articles, and contacts with researchers. Meta-analytic approaches were used in synthesizing findings.
Main Outcome Measures:
Intervention effects on symptoms of depression, anxiety, and anger, stress, and CD4 cell counts were assessed.
Results:
Data from 15 controlled trials were analyzed. Significant intervention effects were observed for improving symptoms of depression (
d
= 0.33), anxiety (
d
= 0.30), anger (
d
= 1.00), and stress (
d
= 0.43). There is limited evidence suggesting intervention effects on CD4 cell counts (
d
= 0.08). The aggregated effect size estimates for depression and anxiety were statistically significant in trials that provided stress management skills training and had more than 10 intervention sessions.
Conclusion:
CBIs are efficacious in improving various psychological states of PLWH. Future research should examine the relationship among interventions, psychological states, medication adherence, and immune functions, and identify other relevant factors associated with intervention effects.
An assessment of liquefaction potential for the Kathmandu Valley considering seasonal variability of the groundwater table has been conducted. To gain deeper understanding seven historical ...liquefaction records located adjacent to borehole datapoints (published in SAFER/GEO-591) were used to compare two methods for the estimation of liquefaction potential. Standard Penetration Test (SPT) blowcount data from 75 boreholes inform the new liquefaction potential maps. Various scenarios were modelled, i.e., seasonal variation of the groundwater table and peak ground acceleration. Ordinary kriging, implemented in ArcGIS, was used to prepare maps at urban scale. Liquefaction potential calculations using the methodology from (Sonmez, Environ Geol 44:862–871, 2003) provided a good match to the historical liquefaction records in the region. Seasonal variation of the groundwater table is shown to have a significant effect on the spatial distribution of calculated liquefaction potential across the valley. The less than anticipated liquefaction manifestations due to the Gorkha earthquake are possibly due to the seasonal water table level.
Abstract Coronary Artery Disease (CAD), caused by the buildup of plaque on the inside of the coronary arteries, has a high mortality rate. To efficiently detect this condition from echocardiography ...images, with lesser inter-observer variability and visual interpretation errors, computer based data mining techniques may be exploited. We have developed and presented one such technique in this paper for the classification of normal and CAD affected cases. A multitude of grayscale features (fractal dimension, entropies based on the higher order spectra, features based on image texture and local binary patterns, and wavelet based features) were extracted from echocardiography images belonging to a huge database of 400 normal cases and 400 CAD patients. Only the features that had good discriminating capability were selected using t -test. Several combinations of the resultant significant features were used to evaluate many supervised classifiers to find the combination that presents a good accuracy. We observed that the Gaussian Mixture Model (GMM) classifier trained with a feature subset made up of nine significant features presented the highest accuracy, sensitivity, specificity, and positive predictive value of 100%. We have also developed a novel, highly discriminative HeartIndex , which is a single number that is calculated from the combination of the features, in order to objectively classify the images from either of the two classes. Such an index allows for an easier implementation of the technique for automated CAD detection in the computers in hospitals and clinics.
Plasma cell hepatitis (PCH), also known as “de novo autoimmune” hepatitis, is an increasingly recognized, but suboptimally named and poorly understood, category of late allograft dysfunction strongly ...resembling autoimmune hepatitis (AIH): They share plasma‐cell‐rich necro‐inflammatory activity on biopsy, autoantibodies and steroid responsiveness, but overlap with rejection is problematic. A retrospective study of clinical, serological, histopathological and IgG4 immunohistological features of PCH (n = 20) in liver allograft recipients, native liver AIH (n = 19) and plasma‐cell‐rich renal allograft rejection (n = 20) showed: (1) high frequency (44%) of HLA‐DR15; (2) less female predominance (p = 0.03) and (3) n = 9/20 PCH recipients showed >25 IgG4+ plasma cells/high‐power field (IgG4+ PCH) versus AIH (n = 1/19, p = 0.008) or plasma‐cell‐rich kidney rejection (n = 2/20, p = 0.03). The IgG4+ PCH (n = 9) subgroup showed lower alanine transaminase (ALT) (p < 0.01) and aspartate transaminase (AST) (p < 0.05) at index biopsy but (a) higher plasma cell number/percentage, (b) more aggressive‐appearing portal/periportal and perivenular necro‐inflammatory activity and (c) more severe portal/periportal fibrosis than IgG4− PCH (n = 11). Significant demographic, histopathologic and plasma cell phenotype differences between PCH and AIH suggest distinct pathogenic mechanisms for at least the IgG4+ PCH subgroup likely representing an overlap between allo‐ and auto‐immunity. IgG4+ PCH was associated with fibrosis, but also highly responsive to increased immunosuppression.
An IgG4‐rich cohort of patients with plasma cell hepatitis after liver transplantation shows demographical, histopathological and plasma cell phenotype features distinct from autoimmune hepatitis in native livers, suggesting distinct pathophysiological disease mechanisms likely representing an overlap between allo‐ and autoimmunity. See editorial by Manns and Mix on page 2792.
The Geostationary Operational Environmental Satellite (GOES) program is developing the Advanced Baseline Imager (ABI), a new generation sensor to be carried onboard the GEOS-R satellite (launch ...expected in 2014). Compared to the current GOES Imager, ABI will have significant advantages for retrieving land surface temperature (LST) as well as providing qualitative and quantitative data for a wide range of applications. The infrared bands of the ABI sensor are designed to achieve a spatial resolution of 2 km at nadir and a noise equivalent temperature of 0.1 K. These improve the imager specifications and compare well with those of polar-orbiting sensors (e.g., Advanced Very High Resolution Radiometer and Moderate Resolution Imaging Spectroradiometer). In this paper, we discuss the development of a split window LST algorithm for the ABI sensor. First, we simulated ABI sensor data using the MODTRAN radiative transfer model and NOAA88 atmospheric profiles. To model land conditions, we developed emissivity data for 78 virtual surface types using the surface emissivity library from Snyder Using the simulation results, we performed regression analyses with the candidate LST algorithms. Algorithm coefficients were stratified for dry and moist atmospheres as well as for daytime and nighttime conditions. We estimated the accuracy and sensitivity of each algorithm for different sun-view geometries, emissivity errors, and atmospheric assessments. Finally, we evaluated the most promising algorithm using real data from the GOES-8 Imager and SURFace RADiation Network. The results indicate that the optimized LST algorithm meets the required accuracy (2.3 K) of the GOES-R mission.
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