A Folding Pathway-Dependent Score to Recognize Membrane Proteins

While various approaches exist to study protein localization, it is still a challenge to predict where proteins localize. Here, we consider a mechanistic viewpoint for membrane localization. Taking into account the steps for the folding pathway of α-helical membrane proteins and relating biophysical parameters to each of these steps, we create a score capable of predicting the propensity for membrane localization and call it FP3mem. This score is driven from the principal component analysis (PCA) of the biophysical parameters related to membrane localization. FP3mem allows us to rationalize the colocalization of a number of channel proteins with the Cav1.2 channel by their fewer propensities for membrane localization

Effects of alpha-tocopherol on fracture resistance after endodontic treatment, bleaching and restoration

Abstract This study evaluated the effects of 10% alphatocopherol on the fracture resistance of endodontically treated teeth subjected to tooth bleaching with hydrogen peroxide and immediately restored with composite resin. Fifty bovine incisors were selected, including 10 sound teeth that constituted the control group (G1 (C)). The remaining 40 teeth, which were endodontically treated, were divided into four groups (n = 10): G2 (CR), consisting of teeth immediately restored with composite resin; G3 (HP + CR), consisting of teeth subjected to tooth bleaching with 38% hydrogen peroxide and immediately restored with composite resin; G4 (HP + SA + CR), which received treatment similar to that used for G3, but with 10% sodium ascorbate gel applied after the bleaching protocol; and G5 (HP + AT + CR), which was similar to G4 but included 10% alphatocopherol gel as an antioxidant. After 24 h, composite restorations were performed, and teeth were subjected to a fracture resistance test at a speed of 0.5 mm/min in an electromechanical testing machine. The axial force was applied with an angle of incidence of 135° relative to the long axis of the root. Data were subjected to ANOVA and Tukey tests (p = 0.05). G1 exhibited the highest fracture resistance (p < 0.05). No significant differences among the other experimental groups were observed. The 10% sodium ascorbate and 10% alphatocopherol gels did not improve the fracture resistance of endodontically treated teeth subjected to bleaching with 38% hydrogen peroxide

A Bi-fluorescence complementation system to detect associations between the Endoplasmic reticulum and mitochondria

Abstract Close contacts between the endoplasmic reticulum membrane and the mitochondrial outer membrane facilitate efficient transfer of lipids between the organelles and coordinate Ca2+ signalling and stress responses. Changes to this coupling is associated with a number of metabolic disorders and neurodegenerative diseases including Alzheimer’s, Parkinson’s and motor neuron disease. The distance between the two membranes at regions of close apposition is below the resolution of conventional light microscopy, which makes analysis of these interactions challenging. Here we describe a new bifluorescence complementation (BiFC) method that labels a subset of ER-mitochondrial associations in fixed and living cells. The total number of ER-mitochondria associations detected by this approach increases in response to tunicamycin-induced ER stress, serum deprivation or reduced levels of mitofusin 2 (MFN2). This method will facilitate the analysis of dynamic interactions between the ER and mitochondrial membranes

Study of effects of different levels of irrigation interval and nitrogen on some physiological traits of signet marigold (Tagetes tenuifolia

Abstract: In order to study the effect of different levels of irrigation interval, N and superabsorbent on seed yield and morphological traits of sesame, a split-split-plot experiment was conducted in Khosr Region, Birjand, Iran in 2009 based on a randomized complete block design. The main plot was irrigation interval at three levels (6, 12 and 18 days), the sub-plot was N fertilization at three levels (0, 100 and 200 kg/ha) and the sub-sub-plot was superabsorbent at two levels (0 and 200 kg/ha). The results of analysis of variance showed that irrigation interval significantly affected seed yield, plant height, stem diameter, auxiliary branch number per plant, first capsule distance from ground and capsule length, so that the increase in irrigation interval from 6 to 18 days decreased seed yield, plant height, stem diameter, auxiliary branch number per plant and capsule length by 44.5, 35.8, 64.3, 49 and 45.7%, respectively. N fertilization significantly affected all studied traits, so that the increase in N level from 0 to 200 kg/ha increased them by 26.6, 14.2, 55.8, 39.9 and 23.7%, respectively. Also, the effect of superabsorbent was significant on all traits except capsule length. In total, given the results of the study, it can be recommended to use irrigation interval of 6 days with the application of 200 kg N/ha in order to realize optimum yield of sesame in Birjand, Iran

Flow boiling heat transfer and pressure drop characteristics of Isobutane in horizontal channels with twisted tapes

© 2020 Elsevier Ltd Using twisted tapes as a passive method for heat transfer improvement in a two-phase flow heat exchanger is experimentally studied. The test evaporator is a copper channel with a length of 1000 mm and an internal diameter of 8.1 mm which is installed horizontally. Three twisted tapes with twist ratios of 4, 10, and 15 are used at refrigerant vapor qualities in the range of 0.1–0.8 and refrigerant mass velocities between 160-350 kgm−2s−1. The natural refrigerant Isobutane (R600a) is chosen as the working fluid because it is environmentally friendly. According to the experiments, installing twisted tapes inside the channel augments both heat transfer rate and pressure drops over the plain channel. It is also observed that for both plain and twisted tape inserted channels, the values of heat transfer coefficients and pressure losses grow by giving rise to the refrigerant mass velocity and vapor quality. Results showed that the system performance factor varied between 0.44–1.09 offering that using twisted tapes as a turbulator is beneficial under specific operating conditions. The empirical data showed that there is an optimum value of the working fluid mass velocity at which the performance of twisted tape inserted channels is higher

The pedunculopontine region and breathing in Parkinson's disease

Objective:Respiratory abnormalities such as upper airway obstruction are common in Parkinson's disease (PD) and are an important cause of mortality and morbidity. We tested the effect of pedunculopontine region (PPNr) stimulation on respiratory maneuvers in human participants with PD, and separately recorded PPNr neural activity reflected in the local field potential (LFP) during these maneuvers. Methods:Nine patients with deep brain stimulation electrodes in PPNr, and seven in globus pallidus interna (GPi) were studied during trials of maximal inspiration followed by forced expiration with stimulation OFF and ON. Local field potentials (LFPs) were recorded in the unstimulated condition. Results:PEFR increased from 6.41 ± 0.63 L/sec in the OFF stimulation state to 7.5 L ± 0.65 L/sec in the ON stimulation state (z = -2.666, df = 8, P = 0.024). Percentage improvement in PEFR was strongly correlated with proximity of the stimulated electrode contact to the mesencephalic locomotor region in the rostral PPN (r = 0.814, n = 9, P = 0.008). Mean PPNr LFP power increased within the alpha band (7-11 Hz) during forced respiratory maneuvers (1.63 ± 0.16 μV2/Hz) compared to resting breathing (0.77 ± 0.16 μV2/Hz; z = -2.197, df = 6, P = 0.028). No changes in alpha activity or spirometric indices were seen with GPi recording or stimulation. Percentage improvement in PEFR was strongly positively correlated with increase in alpha power (r = 0.653, n = 14 (7 PPNr patients recorded bilaterally), P = 0.0096). Interpretation:PPNr stimulation in PD improves indices of upper airway function. Increased alpha-band activity is seen within the PPNr during forced respiratory maneuvers. Our findings suggest a link between the PPNr and respiratory performance in PD