Inter-insertional distance is a poor correlate for ligament load: Analysis from in vivo gait kinetics data

In many analytic models of the knee joint, inter-insertional distance is used as the measure to define the load in a ligament. In addition, the direction of the load is taken to be the direction between the two insertions. Our in vivo data on the ovine ligament loads during gait, however, indicate that a wide range of forces is possible in the ligament for any specified inter-insertional distance. To understand the complex relationship between the bone orientations and ligament load better, an artificial neural network (ANN) model was developed. The six degree-of-freedom (6-DOF) in vivo kinematics of femur relative to tibia (joint kinematics) was used as input, and the magnitude of the anterior cruciate ligament (ACL) load was used as output/target. While the trained network was able to predict peak ligament loads with remarkable accuracy (R-square=0.98), an explicit relationship between joint kinematics and ACL load could not be determined. To examine the experimental and ANN observations further, a finite element (FE) model of the ACL was created. The geometry of the FE model was reconstructed from magnetic resonance images (MRI) of an ACL, and an isotropic, hyperelastic, nearly incompressible constitutive model was implemented for the ACL. The FE simulation results also indicate that a range of loads is possible in the ACL for a given inter-insertional distance, in concordance with the experimental/ANN observations. This study provides new insights for models of the knee joint; a simple force–length relationship for the ligament is not exact, nor is a single point to single point direction. More detailed microstructure-function data is required.     

Density functional theory studies of oxygen and carbonate binding to a dicopper patellamide complex

In this work we present results of density functional theory (DFT) calculations on dicopper patellamides and their affinity for molecular oxygen and carbonate. Patellamides are cyclic octapeptides that are produced by a cyanobacterium, and may show promise as therapeutics. Thus, carbonate binding to a dicopper patellamide center gives a stable cyclic octapeptide with a twist of almost 90°. The system exists in close-lying open-shell singlet and triplet spin states with two unpaired electrons in orthogonal σ^∗ orbitals on each metal center. Subsequently, we replaced carbonate with dioxygen and found a stable Cu₂(μ-O)₂ diamond shaped patellamide core. In this structure the original dioxygen bond is significantly weakened to essentially a single bond, which should enable the system to transfer these oxygen atoms to substrates. We predicted the IR and Raman spectra of the Cu₂(μ-O)₂ diamond shaped patellamide structure using density functional theory and found a considerable isotope effect on the O-O stretch vibration for ¹⁶O₂ versus ¹⁸O₂ bound structures. Our studies reveal that carbonate forms an extremely stable complex with dicopper patellamide, but that additional molecular oxygen to this system does not give a potential oxidant. Therefore, it is more likely that carbonate prepares the system for dioxygen binding by folding it into the correct configuration followed in the proposed catalytic cycle by a protonation event preceding dioxygen binding to enable the system to reorganize to form a stable Cu₂(μ-O)₂-patellamide cluster. Alternatively, carbonate may act as an inhibitor that blocks the catalytic activity of the system. It is anticipated that the Cu₂(μ-O)₂-patellamide structure is a potential active oxidant of the dicopper patellamide complex.     

In Silico Designing a Candidate Vaccine Against Breast Cancer

International Journal of Peptide Research and Therapeutics - Breast cancer (BC) is the most common type of women’s cancer with a prevalence of about 25%, although it is rare in men...     

Hydrogen production by sorption-enhanced steam reforming of glycerol

Catalytic steam reforming of glycerol for H₂ production has been evaluated experimentally in a continuous flow fixed-bed reactor. The experiments were carried out under atmospheric pressure within a temperature range of 400–700 °C. A commercial Ni-based catalyst and a dolomite sorbent were used for the steam reforming reactions and in situ CO₂ removal. The product gases were measured by on-line gas analysers. The results show that H₂ productivity is greatly increased with increasing temperature and the formation of methane by-product becomes negligible above 500 °C. The results suggest an optimal temperature of ∼500 °C for the glycerol steam reforming with in situ CO₂ removal using calcined dolomite as the sorbent, at which the CO₂ breakthrough time is longest and the H₂ purity is highest. The shrinking core model and the 1D-diffusion model describe well the CO₂ removal under the conditions of this work.     

Antixenosis resistance to Aphis fabae Scopoli (Hemiptera:Aphididae) in bean cultivars

Aphis fabae Scopoli (Hemiptera: Aphididae) is heteroecious and polyphagous that is harmful on secondary hosts such as many important agricultural products like beet, common bean, faba bean, potato and other products. This aphid is the cause of more than 33 viral transition. One of the mechanisms of plant resistance is antixenosis. This mechanism influences on placement and nutrition of pests that result in less damage. In this study, antixenosis resistance mechanism of 12 varieties of bean was tested. Experiment was on completely randomised design with 12 treatments and 6 replications. Bean varieties include of white bean, kidney bean and wax bean, and each replication includes one pot, and then, pots were placed under the isolated room that were filled with winged adult aphids in circular form. After 24 and 48?h, aphids and level of nymph production were counted. The lowest number of adult aphids was observed on Sayad variety among 12 varieties (during 24?h). The least number of produced nymphs was in Daneshkade variety. In Sayad variety, the frequency of matured insects and produced nymphs was minimum.     

Environmental and economic impact of using new-generation wide-base tires

Purpose

New-generation wide-base tire (NG-WBT) is known for improving fuel economy and at the same time for potentially causing a greater damage to pavement. No study has been conducted to evaluate the net environmental saving of the combined system of pavements and NG-WBT. This study adopted a holistic approach (life cycle assessment [LCA] and life cycle costing [LCC]) to quantitatively evaluate the environmental and economic impact of using NG-WBT.

Methods

The net effect of different levels of market penetration of NG-WBT on energy consumption, global warming potential (GWP), and cost based on the fatigue cracking and rutting performance of two different asphalt concrete (AC) pavement structures was evaluated. The performance of pavements was determined based on pavement design lives; pavement surface characteristics, and pavement critical strain responses obtained from the artificial neural network (ANN) based on finite element (FE) simulations were used to calculate design lives of pavements. Based on the calculated design lives, life cycle inventory (LCI) and cost databases, and rolling resistance (RR) models previously developed by the University of Illinois at Urbana-Champaign (UIUC) were used to calculate the environmental and economic impact of the combined system.

Results and discussion

The fuel economy improvement using NG-WBT is 1.5% per axle. Scenario-based case studies were conducted. Considering 0% NG-WBT market penetration (or 100% standard dual tire assembly [DTA]) as a baseline, scenario 1 assumed the same fatigue and rutting potential between NG-WBT and DTA; therefore, the only difference came from fuel economy improvement of using NG-WBT. In scenario 2, pavement fatigue cracking potential determined the pavement design life; both thick and thin AC overlay sections experienced positive net environmental savings, but mixed net economic savings. In scenario 3, pavement rutting potential determined the pavement design life; the thick AC overlay section experienced positive net environmental savings, but mixed net economic savings. The thin section experienced negative net environmental and economic savings.

Conclusions

The outcomes of scenario-based case studies indicated that NG-WBT can result in significant savings in life cycle energy consumption and cost, and GWP; however, these benefits were sensitive to the method used to determine the pavement performance; especially, a small change in pavement strain can result in significant change in pavement life. In addition, the effect of fuel price/economy improvement, discount rate, and International Roughness Index (IRI) threshold values was studied in the sensitivity analyses.

     

Decreased levels of soluble Toll-like Receptor 2 in patients with asthma

Background:

Recently, reports have indicated a role for the membrane form of Toll-like Receptor 2 (TLR2) in asthma pathogenesis. In this study we examined soluble TLR2 levels in serum and sputum of asthmatic and healthy subjects.

Methods:

Serum and sputum samples were obtained from 33 asthmatic and 19 healthy subjects. The asthmatics were classified into four groups according to the Global Initiative for Asthma. A sandwich ELISA was developed to measure soluble TLR2 (sTLR2) in serum and sputum. TLR2 mRNA expression was determined by semi-quantitative RT-PCR of all sputum samples.

Results:

The mean sTLR2 levels from serum and sputum of asthmatics were significantly lower than those from healthy subjects. Moreover, sTLR2 concentration decreased concomitantly with asthma severity. The differences observed, however, were not statistically significant. TLR2/GAPDH mRNA of sputum leukocytes was also significantly lower in asthmatics than in healthy subjects.

Conclusion:

This study demonstrated for the first time thatsTLR2 levels are lower in serum and sputum samples from asthmatic than from healthy subjects, and this could be an indicator of TLR2 expression. We also found that sTLR2 concentration in serum decreased concomitantly with an increase of asthma severity clinical score. Key Words: Asthma, Expression, TLR2 mRNA, Soluble Toll-like receptor