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Buffer capacity

Corrado Spadafora
Epigenetics is increasingly regarded as a potential contributing factor to evolution. Building on apparently unrelated results, here I propose that RNA-containing nanovesicles, predominantly small regulatory RNAs, are released from somatic tissues in the bloodstream, cross the Weismann barrier, reach the epididymis, and are eventually taken up by spermatozoa; henceforth the information is delivered to oocytes at fertilization. In the model, a LINE-1-encoded reverse transcriptase activity, present in spermatozoa and early embryos, plays a key role in amplifying and propagating these RNAs as extrachromosomal structures...
December 6, 2017: Progress in Biophysics and Molecular Biology
Xiaosha Luo, Xufeng Yuan, Shiyu Wang, Fanrong Sun, Zhanshan Hou, Qingxiu Hu, Limei Zhai, Zongjun Cui, Yajie Zou
Spent mushroom substrate (SMS) is a potential biomass material generated during mushroom cultivation. In this study, the methane yield and microbial community resulting from co-digestion of SMS and dairy manure (DM) at different mixing ratios (0:4, 1:1, 3:1, and 1:3), were evaluated. Co-digestion analysis showed that the methane yield from the mixtures was 6%-61% higher than the yield from SMS or DM alone, indicating a synergistic effect of co-digestion of SMS with DM. For the SMS of F.velutipes (SFv) and P...
November 29, 2017: Bioresource Technology
E M Sander, B Virdis, S Freguia
Addition of an external carbon source is usually necessary to guarantee a sufficiently high C/N ratio and enable denitrification in wastewater treatment plants (WWTPs). Alternatively, denitrification processes using autotrophic microorganisms have been proposed i.e., with the use of H2 as electron donor or with the use of cathodic denitrification in bioelectrochemical systems (BES), in which electrons are transferred directly to a denitrifying biofilm. The aim of this work was to investigate and demonstrate the feasibility of applying an easy-to-operate BES as a polishing mechanism for treated secondary clarified effluent from a municipal WWTP, containing low levels of organic matter, buffer capacity and low concentrations of remaining nitrate...
December 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Mohammed S Al-Ak'hali, Esam S Halboub, Osama H Mujam, Noor M Alahmar, Salehah A Jerah, Fahad A Mutawwam
To evaluate the salivary flow rate (SFR),  pH, and buffer capacity (BC) among healthy shammah users (SU) in comparison with healthy non-shammah users (NSU). Methods: This case-control study was conducted at the College of Dentistry, Jazan University, Jazan, Kingdom of Saudi Arabia between March 2016 and May 2017. A sample of 27 SU and 30 NSU were recruited. Unstimulated saliva was collected and SFR, pH, and BC were determined. Dental health was assessed using the decay-missing-filled teeth (DMFT) index.  Results: Shammah users were slightly older than NSU (28...
December 2017: Saudi Medical Journal
Slađana Strmečki, Emil Paleček
Previously, it has been shown that proteins and some polysaccharides (PSs) catalyse hydrogen evolution, producing electrochemical signals on mercury electrodes. The catalytic hydrogen evolution reaction (CHER) of the above-mentioned biomacromolecules was studied by voltammetric and chronopotentiometric stripping (CPS) methods. To obtain more information about electrode processes involving CHER, here we used protein such as BSA, and chitosan as a PS; in addition, we investigated dextran as a control PS not involved in CHER...
November 29, 2017: Bioelectrochemistry
Hongen Wang, Xu Zhao, Kaili Yin, Yu Li, Lihua Chen, Xiao-Yu Yang, WenJun Zhang, Bao-Lian Su, Guozhong Cao
Vanadium oxides are promising anode materials for lithium ion batteries (LIBs) due to their high capacity, good safety and low cost. However, their practical application has been deferred by the poor rate capability and cycling stability. In this work, we report the designed synthesis of porous V2O3/VO2@carbon heterostructure electrode for high performance LIBs. The synergic effects of porous nanostructures, phase hybridization with self-building electric field at heterointerface, and conductive carbon implantation effectively enhance the electronic/ionic conduction and buffer the volume variation in the composite material...
December 1, 2017: ACS Applied Materials & Interfaces
Marcel Kansy, Alexandra Gurowietz, Christian Wilhelm, Reimund Goss
BACKGROUND: The preparation of functional thylakoid membranes from diatoms with a silica cell wall is still a largely unsolved challenge. Therefore, an optimized protocol for the isolation of oxygen evolving thylakoid membranes of the centric diatom Cyclotella meneghiniana has been developed. The buffer used for the disruption of the cells was supplemented with polyethylene glycol based on its stabilizing effect on plastidic membranes. Disruption of the silica cell walls was performed in a French Pressure cell and subsequent linear sorbitol density gradient centrifugation was used to isolate the thylakoid membrane fraction...
November 25, 2017: BMC Plant Biology
William Wang, Jiayuan Hou, Zhenghua Zhu, Hao Fang
Mitochondrial dysfunction has historically been linked to the cessation of cell function and ageing. Downstream effects such as reduced calcium buffering capacity, elevated levels of reactive oxygen species, and alterations in adenosine-5'-triphosphate are linked to a wide variety of pathological diseases. The importance of the mitochondria has increasingly been highlighted due to its potential as a therapeutic target for drug intervention and cell elimination in cancer. In addition, due to its origin, drugs targeting bacteria are required to be thoroughly tested prior to administration to prevent toxicity for the mitochondria...
2017: Advances in Experimental Medicine and Biology
Min-Jae Choi, Jongsoon Kim, Jung-Keun Yoo, Soonmin Yim, Jaebeom Jeon, Yeon Sik Jung
Na/FeSx batteries have remarkable potential applicability due to their high theoretical capacity and cost-effectiveness. However, realization of high power-capability and long-term cyclability remains a major challenge. Herein, ultrafine Fe7 S8 @C nanocrystals (NCs) as a promising anode material for a Na-ion battery that addresses the above two issues simultaneously is reported. An Fe7 S8 core with quantum size (≈10 nm) overcomes the kinetic and thermodynamic constraints of the Na-S conversion reaction. In addition, the high degree of interconnection through carbon shells improves the electronic transport along the structure...
November 24, 2017: Small
Luc De Meester, Robby Stoks, Kristien I Brans
Climate change profoundly impacts ecosystems and their biota, resulting in range shifts, novel interactions, food web alterations, changed intensities of host-parasite interactions, and extinctions. An increasing number of studies documented evolutionary changes in, amongst others, phenology and thermal tolerance. In this opinion paper, we argue that, while evolutionary responses have the potential to provide a buffer against extinctions or range shifts, a number of constraints and complexities blur this simple prediction...
November 23, 2017: Integrative Zoology
Guoxin Gao, Yang Xiang, Shiyao Lu, Bitao Dong, Sheng Chen, Lei Shi, Yuankun Wang, Hu Wu, Zhaoyang Li, Amr Abdelkader, Kai Xi, Shujiang Ding
The Ge-based compounds show great potential as replacements for traditional graphite anode in lithium-ion batteries (LIBs). However, large volume changes and low conductivity of such materials result in a poor electrochemical cycling and rate performance. Herein, we fabricate a self-supported and three-dimensional (3D) sponge-like structure of interlinked Zn2GeO4 ultrathin nanosheets anchored vertically on a nickel foam (ZGO NSs@NF) via a simple hydrothermal process assisted by cetyltrimethyl ammonium bromide (CTAB)...
November 22, 2017: Nanoscale
Dag Dolmen, Anders Gravbrøt Finstad, Jon Kristian Skei
We here report the first sign of amphibian recovery after a strong decline due to acidic precipitation over many decades and peaking around 1980-90. In 2010, the pH level of ponds and small lakes in two heavily acidified areas in southwestern Scandinavia (Aust-Agder and Østfold in Norway) had risen significantly at an (arithmetic) average of 0.14 since 1988-89. Parallel with the general rise in pH, amphibians (Rana temporaria, R. arvalis, Bufo bufo, Lissotriton vulgaris, and Triturus cristatus) had become significantly more common: the frequency of amphibian localities rose from 33% to 49% (n = 115), and the average number of amphibian species per locality had risen from 0...
November 21, 2017: Ambio
Hao Cao, Chengcheng Li, Jing Zhao, Fang Wang, Tianwei Tan, Luo Liu
Glutathione (GSH) is an important reducing agent in the living cells. It is synthesized by a two-step reaction and requires two molecules of adenosine triphosphate (ATP) for one molecule GSH. The enzymatic cascade reaction in vitro is a promising approach to achieve a high titer and limit side reactions; although, a cost-effective phosphate donor for ATP regeneration is required. Triphosphate (PolyP(3)), tetraphosphate (PolyP(4)), and hexametaphosphate (PolyP(6)) were investigated in this study. Triphosphate inhibited the bifunctional GSH synthetase (GshF) from Streptococcus agalactiae, while no significant inhibition was observed by adding hexametaphosphate...
November 21, 2017: Applied Biochemistry and Biotechnology
Li Sun, Yu Zhang, Deyang Zhang, Yihe Zhang
A facile solution-based method was developed to combine the advantage of amorphous nanoscale red P sheets and highly conductive graphene, forming a high-performance P/graphene composite anode for advanced lithium ion batteries. Graphene can be easily expanded into a 3D framework in solution with rich interior porosity and abundant adsorption points, which enables a large percentage of red P to be loaded and form a uniform P/graphene hybrid structure. The nanoscale and amorphous features of red P effectively reduce the volume expansion and mechanical stress within individual P sheets, thereby alleviating P pulverization during cycling...
November 22, 2017: Nanoscale
Xiaoqiao Chen, Zhiguang Cao, Lidan Xing, Youhao Liao, Yongcai Qiu, Weishan Li
In this paper, MnO2 nanoboxes coated with poly(3,4-ethylenedioxythiophene) film (denoted as MnO2@PEDOT) are investigated as an anode material in lithium-ion batteries. The MnO2 nanoboxes are developed through the surface chemical oxidation decomposition of MnCO3 cubes and the subsequent removal of their remaining cores. PEDOT is coated on the surface of MnO2 nanoboxes via in situ polymerization of 3,4-ethylenedioxythiophene. The charge-discharge tests demonstrate that this special configuration endows the resulting MnO2@PEDOT with remarkable electrochemical performances, that is a reversible capacity of 628 mA h g(-1) after 850 cycles at a current density of 1000 mA g(-1) and a rate capacity of 367 mA h g(-1) at 3000 mA g(-1)...
November 21, 2017: Nanoscale
Sarvenaz Sabouri-Rad, Reza Kazemi Oskuee, Asma Mahmoodi, Leila Gholami, Bizhan Malaekeh-Nikouei
Introduction: Cationic polymers have the potential to be modified to achieve an ideal gene vector lacking viral vector defects. The aim of the present study was to improve polyallylamine (PAA) transfection efficiency and to reduce cytotoxicity by incorporating of cell-penetrating peptides (CPPs). Methods: To prepare the peptide-based polyplexes, PAA (15 kDa) was modified with 2 peptides (TAT and CyLoP-1) by covering the 0.5% and 1% of amines. Buffer capacity and DNA condensation ability of modified polymer, particle size and zeta potential of nanoparticles, cell viability, and transfection activity of vectors were evaluated...
2017: BioImpacts: BI
Katerina Iliou, Anđelija Malenović, Yannis L Loukas, Yannis Dotsikas
A novel Liquid Chromatography-tandem mass spectrometry (LC-MS/MS) method is presented for the quantitative determination of two potential genotoxic impurities (PGIs) in rabeprazole active pharmaceutical ingredient (API). In order to overcome the analytical challenges in the trace analysis of PGIs, a development procedure supported by Quality-by-Design (QbD) principles was evaluated. The efficient separation between rabeprazole and the two PGIs in the shortest analysis time was set as the defined analytical target profile (ATP) and to this purpose utilization of a switching valve allowed the flow to be sent to waste when rabeprazole was eluted...
November 12, 2017: Journal of Pharmaceutical and Biomedical Analysis
Stanley S Hillman, Michael S Hedrick
Body temperature increases in ectothermic vertebrates characteristically lead to both increases in arterial PCO2 (PaCO2) and declines in resting arterial pH (pHa) of about 0.017 pH units/°C increase in temperature. This 'alphastat' pH pattern has previously been interpreted as being evolutionarily-driven by the maintenance of a constant protonation state on the imidazole moiety of histidine protein residues, hence stabilizing protein structure-function. Analysis of the existing data for interclass responses of ectothermic vertebrates show different degrees of PaCO2 increases and pH declines with temperature between the classes with reptiles>amphibians>fish...
November 17, 2017: Journal of Experimental Biology
Zhu-Yin Sui, Pei-Ying Zhang, Meng-Ying Xu, Yuwen Liu, Zhi-Xiang Wei, Bao-Hang Han
Metal-organic frameworks (MOFs) are hybrid inorganic-organic materials that can be used as effective precursors to prepare various functional nanomaterials for energy-related applications. Nevertheless, most MOF-derived metal oxides exhibit low electrical conductivity and mechanical strain. These characteristics limit their electrochemical performance and hamper their practical application. Herein, we report a rational strategy for enhancing the lithium storage performance of MOF-derived metal oxide. The hierarchically porous Co3O4@NGN is successfully prepared by embedding ZIF-67-derived Co3O4 particles in a nitrogen-doped graphene network (NGN)...
November 17, 2017: ACS Applied Materials & Interfaces
Ji-Lei Shi, Ran Qi, Xu-Dong Zhang, Peng-Fei Wang, Weigui Fu, Ya-Xia Yin, Jian Xu, Li-Jun Wan, Yu-Guo Guo
Delivery of high-capacity with high thermal and air stability is a great challenge in developing of Ni-rich layered cathodes for commercialized Li-ion batteries (LIBs). Herein we present a surface concentration-gradient spherical particle with varying elemental composition from the outer end LiNi1/3Co1/3Mn1/3O2 (NCM) to the inner end LiNi0.8Co0.15Al0.05O2 (NCA). This cathode material with the merit of NCM concentration-gradient protective buffer and the inner NCA core shows high capacity retention of 99.8% after 200 cycles at 0...
November 17, 2017: ACS Applied Materials & Interfaces
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