The rhizosphere is colonized by a mass of microbes, including bacteria capable of promoting plant growth that carry out complex interactions. Here, by using a sterile experimental system, we demonstrate that Sphingomonas sp. Cra20 promotes the growth of Arabidopsis thaliana by driving developmental plasticity in the roots, thus stimulating the growth of lateral roots and root hairs. By investigating the growth dynamics of A. thaliana in soil with different water-content, we demonstrate that Cra20 increases the growth rate of plants, but does not change the time of reproductive transition under well-water condition. The results further show that the application of Cra20 changes the rhizosphere indigenous bacterial community, which may be due to the change in root structure. Our findings provide new insights into the complex mechanisms of plant and bacterial interactions. The ability to promote the growth of plants under water-deficit can contribute to the development of sustainable agriculture.

More and more stringent requirements for pollution control and the implementation of the new discharge standard for landfill leachate make the development and application of landfill leachate treatment a research focus. The aim of the review is to determine appropriate technique for effective treatment of landfill leachate. In the paper, various leachate treatment technologies are presented and summarized, the key control parameters and some main problems are discussed from a technological point of view. It is proposed that the improvement of existing technical and the development and industrial application of a new treatment for landfill leachate are necessary. The development and application of integrated leachate treatment process of different physical, biological and chemical technologies could be a suitable option to reduce the contamination levels of leachate. Particularly, advanced oxidation technologies and an efficient integration between physical-chemical processes and biochemical processes are indicated as a significant research direction of new technology development

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Porous silicon nitride (Si3N4) ceramics with about 50% porosity were fabricated by pressureless sintering of α‐Si3N4 powder with 5 wt% sintering additive. Four types of sintering aids were chosen to study their effect on the microstructure and mechanical properties of porous Si3N4 ceramics. XRD analysis proved the complete formation of a single β‐Si3N4 phase. Microstructural evolution and mechanical properties were dependent mostly on the type of sintering additive. SEM analysis revealed the resultant porous Si3N4 ceramics as having high aspect ratio, a rod‐like microstructure, and a uniform pore structure. The sintered sample with Lu2O3 sintering additive, having a porosity of about 50%, showed a high flexural strength of 188 MPa, a high fracture toughness of 3.1 MPa·m1/2, due to fine β‐Si3N4 grains, and some large elongated grains.

Background: Computer-aided diagnosis (CAD) systems are being applied to the ultrasonographic diagnosis of malignant thyroid nodules, but it remains controversial whether the systems add any accuracy for radiologists. Objective: To determine the accuracy of CAD systems in diagnosing malignant thyroid nodules. Methods: PubMed, EMBASE, and the Cochrane Library were searched for studies on the diagnostic performance of CAD systems. The diagnostic performance was assessed by pooled sensitivity and specificity, and their accuracy was compared with that of radiologists. The present systematic review was registered in PROSPERO (CRD42019134460). Results: Nineteen studies with 4,781 thyroid nodules were included. Both the classic machine learning-and the deep learning-based CAD system had good performance in diagnosing malignant thyroid nodules (classic machine learning: sensitivity 0.86 [95% CI 0.79-0.92], specificity 0.85 [95% CI 0.77-0.91], diagnostic odds ratio (DOR) 37.41 [95% CI 24.91-56.20]; deep learning: sensitivity 0.89 [95% CI 0.81-0.93], specificity 0.84 [95% CI 0.75-0.90], DOR 40.87 [95% CI 18.13-92.13]). The diagnostic performance of the deep learning-based CAD system was comparable to that of the radiologists (sensitivity 0.87 [95% CI 0.78-0.93] vs. 0.87 [95% CI 0.85-0.89], specificity 0.85 [95% CI 0.76-0.91] vs. 0.87 [95% CI 0.81-0.91], DOR 40.12 [95% CI 15.58-103.33] vs. DOR 44.88 [95% CI 30.71-65.57]). Conclusions: The CAD systems demonstrated good performance in diagnosing malignant thyroid nodules. However, experienced radiologists may still have an advantage over CAD systems during real-time diagnosis.

Deposition of nanocrystalline TiO 2 coating at low temperature is becoming more attractive due to the possibility for continuous roll production of the coating for assembly lines of dye-sensitized solar cell (DSC) at a low cost. In this study, porous nano-TiO 2 coating was deposited by vacuum cold spraying (VCS) at room temperature on a conducting glass substrate using commercial P25 nanocrystalline TiO 2 powder. The microstructure of TiO 2 coating was characterized by field emission scanning electron microscopy (FESEM) and nitrogen adsorption test. A commercial dye (N719) was adsorbed on the surface of TiO 2 particles within the coating to assemble a DSC. The cell performance was evaluated by employing simulated solar light at an intensity of 100 mW/cm 2 . The results showed that TiO 2 coating was deposited by the agglomerates of nano-TiO 2 powders. The Brunauer-Emmett-Teller (BET) test of the as-sprayed TiO 2 coating yielded a porosity of 49% and an average pore size of 17 nm. The assembled solar cell yielded a short-circuit current density of 7.3 mA/cm 2 and an energy conversion efficiency of 2.4%. The test results indicate that VCS was a promising method to deposit nanocrystalline TiO 2 coatings at low temperature applied to DSCs.

Taking together from both physiological and genetic levels, we suggest that FGF21 is inversely associated with regional BMD. And we haven't observed sex-specific effect in this study.

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