Onion plants (Allium cepa L.) react differently to salinity levels according to the regulation of aquaporins.

As salinity is one of the main environmental stresses that reduces the growth and productivity of crops by reducing water uptake and transport, in this work, we associated the physiological tolerance response of onion to increased NaCl concentration (from 25, 50, 75, to 100 mM) with the expression of aquaporins. Measurements of transpiration, gas exchange and nutrients content in leaf, roots and bulb tissues were determined in relation to the expression of PIP2, PIP1, and TIP2 aquaporin genes. The results indicated a significant decrease in growth in leaves, roots and bulbs only when 50 mM NaCl was applied. However, this was not correlated with the rest of the parameters, such as transpiration, number of stomata, osmotic potential, or chlorophyll concentration. In this way, the finding that the decreases in Mn, Zn and B observed in leaves, roots and bulbs at 50 mM NaCl were related to the expression of aquaporins, leaded to propose two phases of responses to salinity depending on level of NaCl. Therefore, the activation of PIP2 at 75 mM, in relation to Zn uptake, is proposed as relevant in the response of onion to high salinity.

Functionalized Cellulose for the Controlled Synthesis of Novel Carbon-Ti Nanocomposites: Physicochemical and Photocatalytic Properties.

Carbon-Ti nanocomposites were prepared by a controlled two-step method using microcrystalline cellulose as a raw material. The synthesis procedure involves the solubilization of cellulose by an acid treatment (H3PO4 or HNO3) and the impregnation with the Ti precursor followed of a carbonization step at 500 or 800 °C. The type of acid treatment leads to a different functionalization of cellulose with phosphorus- or oxygen-containing surface groups, which are able to control the load, dispersion and crystalline phase of Ti during the composite preparation. Thus, phosphorus functionalities lead to amorphous carbon-Ti composites at 500 °C, while TiP2O7 crystals are formed when prepared at 800 °C. On the contrary, oxygenated groups induce the formation of TiO2 rutile at an unusually low temperature (500 °C), while an increase of carbonization temperature promotes a progressive crystal growth. The removal of Orange G (OG) azo dye in aqueous solution, as target pollutant, was used to determine the adsorptive and photocatalytic efficiencies, with all composites being more active than the benchmark TiO2 material (Degussa P25). Carbon-Ti nanocomposites with a developed micro-mesoporosity, reduced band gap and TiO2 rutile phase were the most active in the photodegradation of OG under ultraviolet irradiation.

Identification of the AQP members involved in abiotic stress responses from Arabidopsis.

Aquaporins (AQPs) constitute a highly diverse family of water channel proteins that play crucial biological functions in plant growth and development and stress physiology. In Arabidopsis, 35 AQPs are classified into four subfamilies (PIPs, TIPs, NIPs and SIPs). However, knowledge about the roles of different subfamily AQPs remains limited. Here, we explored the chromosomal location, gene structure and expression patterns of all AQPs in different tissues or under different abiotic stresses based on available microarray data. Tissue expression analysis showed that different AQPs had various expression patterns in tissues (root, leaf, flower and seed). Expression profiles under stress conditions revealed that most AQPs were responsive to osmotic, salt and drought stresses. Phenotypic and physiological identification showed that Tip2;2 loss-of-function mutant exhibited less sensitive to abiotic stresses (mannitol, NaCl and PEG) compared with wild-type, as evident by analysis of germination rate, root growth, survival rate, ion leakage, malondialdehyde (MDA) and proline contents. Mutant of TIP2;2 modulated the transcript levels of SOS1, SOS2, SOS3, DREB1A, DREB2A and P5CS1, under abiotic stress conditions. This study provides a basis for further functional identification of stress-related candidate AQPs in Arabidopsis.

Evaluation of Diastolic Function in Patients with Normal Perfusion and Type 2 Diabetes Mellitus with Gated Single-photon Emission Computed Tomography.

Early identification of diastolic dysfunction of patients with diabetes is important in preventing cardiac events. In this study, we aimed to show that both myocardial perfusion and diastolic function parameters can be evaluated in diabetic patients with possible silent cardiac symptoms using gated single-photon emission computed tomography (G-SPECT). We examined eighty patients: Forty with and forty without diabetes. The patients were compared in terms of systolic and diastolic parameters obtained using G-SPECT. 99mTc-sestamibi was used to obtain 8-frame images in each cardiac cycle, with calculation of the left ventricular ejection fraction (LVEF), peak filling rate (PFR), mean filling rate during the first third of diastolic time (MFR/3), and time to peak filling (TTPF) using the QGS software. G-SPECT results were compared in forty diabetic and forty nondiabetic patients of similar age and sex. Of the diastolic function parameters, PFR was found to be lower in patients with than without diabetes (2.31 ± 0.68 vs. 2.76 ± 0.68, respectively; P = 0.004). The TTPF and MFR/3 in both groups were similar. PFR was negatively correlated with end-diastolic volume and end-systolic volume (ESV) and positively correlated with LVEF. This correlation was stronger in patients with diabetes. The diastolic parameter PFR, obtained using G-SPECT, was significantly lower in patients with than without diabetes. We believe that these parameters should be noted for the early diagnosis or prevention of heart disease in patients with a risk of diastolic dysfunction.

TiP2O7 and Expanded Graphite Nanocomposite as Anode Material for Aqueous Lithium-Ion Batteries.

This paper reports a facile sol-gel synthesis method to successfully prepare the TiP2O7/expanded graphite (EG) nanocomposite as an advanced anode material for aqueous lithium-ion batteries. The constructed TiP2O7 nanocomposites (50-100 nm) are in situ encapsulated in the pore and layer structure of expanded graphite with good conductivity and high specific surface area. As a consequence, the resulting TiP2O7/EG electrode exhibits a reversible capacity of 66 mAh g-1 at 0.1 A g-1 with an appropriate potential of -0.6 V before hydrogen evolution in aqueous electrolytes, and also demonstrates greatly enhanced cycling stability with 75% capacity retention after 1000 cycles at the current density of 0.5 A g-1. A full cell consisting of TiP2O7/EG anode, LiMn2O4 cathode, and 1 M Li2SO4 electrolyte delivers a specific energy of 60 Wh kg-1 calculated on the weight of both cathode and anode materials with an operational voltage of 1.4 V. It also exhibits superior rate capability and remarkable cycling performance with a capacity maintenance of 66% over 500 cycles at 0.2 A g-1 and 61% at 1 A g-1 over 2000 cycles.