N-doped carbon sheets supported P-Fe3O4-MoO2 for freshwater and seawater electrolysis.

Electric-driven freshwater/seawater splitting is an attractive and sustainable route to realize the generation of H2 and O2. Molybdenum-based oxides exhibit poor activity toward freshwater/seawater electrolysis. Herein, we adjusted the electronic structure of MoO2 by constructing N-doped carbon sheets supported P-Fe3O4-MoO2 nanosheets (P-Fe3O4-MoO2/NC). P-Fe3O4-MoO2/N-doped carbon sheets were precisely prepared by pyrolysis of Schiff base Fe complex and MoO3 nanosheets through phosphorization. Benefiting from the unique structures of the samples, it required 119/145 mV to drive freshwater/seawater reduction reaction at 10 mA/cm2. P-Fe3O4-MoO2/NC catalysts exhibited superior freshwater/seawater oxidation reactivity with 180/189 mV at 10 mA/cm2 compared with commercial RuO2. The low cell voltages for P-Fe3O4-MoO2/NC were 1.47 and 1.59 V towards freshwater and seawater electrolysis, respectively. Our work might shed light on the structural modulation of Mo-based oxides for enhancing freshwater and seawater electrolysis activity.

Nanofluids of Amphiphilic Kaolinite-Based Janus Nanosheets for Enhanced Oil Recovery: The Importance of Stable Emulsion.

To meet the increasing global demand for energy, better recovery of crude oil from reservoirs must be achieved using methods that are economical and environmentally benign. Here, we have developed a nanofluid of amphiphilic clay-based Janus nanosheets via a facile and scalable method that provides potential to enhance oil recovery. With the aid of dimethyl sulfoxide (DMSO) intercalation and ultrasonication, kaolinite was exfoliated into nanosheets (KaolNS) before being grafted with 3-methacryloxypropyl-triemethoxysilane (KH570) on the Alumina Octahedral Sheet at 40 and 70 °C to form amphiphilic Janus nanosheets (i.e., KaolKH@40 and KaolKH@70). The amphiphilicity and Janus nature of the KaolKH nanosheets have been well demonstrated, with distinct wettability obtained on two sides of the nanosheets, and the KaolKH@70 was more amphiphilic than the KaolKH@40. Upon preparing Pickering emulsion in a hydrophilic glass tube, the KaolKH@40 preferentially stabilized emulsions, while the KaolNS and KaolKH@70 tended to form an observable and high-strength elastic planar interfacial film at the oil-water interface as well as films climbing along the tube's surface, which were supposed to be the result of emulsion instability and the strong adherence of Janus nanosheets towards tube's surface. Subsequently, the KaolKH was grafted with poly(N-Isopropylacrylamide) (PNIPAAm), and the prepared thermo-responsive Janus nanosheets demonstrated a reversible transformation between stable emulsion and the observable interfacial films. Finally, when the samples were subjected to core flooding tests, the nanofluid containing 0.01 wt% KaolKH@40 that formed stable emulsions showed an enhanced oil recovery (EOR) rate of 22.37%, outperforming the other nanofluids that formed observable films (an EOR rate ~13%), showcasing the superiority of Pickering emulsions from interfacial films. This work demonstrates that KH-570-modified amphiphilic clay-based Janus nanosheets have the potential to be used to improve oil recovery, especially when it is able to form stable Pickering emulsions.

Competitive Adsorption of Interfacially Active Nanoparticles and Anionic Surfactant at the Crude Oil-Water Interface.

The interfacial activity of poly(N-isopropylacrylamide) (pNIPAM) nanoparticles in the absence and presence of an anionic surfactant (sodium dodecyl sulfate, SDS) was studied at a crude oil-water interface. Both species are interfacially active and can lower the interfacial tension, but when mixed together, the interfacial composition was found to depend on the aging time and total component concentration. With the total component concentration less than 0.005 wt %, the reduced interfacial tension by pNIPAM was greater than SDS; thus, pNIPAM has a greater affinity to partition at the crude oil-water interface. However, the lower molecular weight (smaller molecule) of SDS compared to pNIPAM meant that it rapidly partitioned at the oil-water interface. When mixed, the interfacial composition was more SDS-like for low total component concentrations (≤ 0.001 wt %), while above, the interfacial composition was more pNIPAM-like, similar to the single component response. Applying a weighted arithmetic mean approach, the surface-active contribution (%) could be approximated for each component, pNIPAM and SDS. Even though SDS rapidly partitioned at the oil-water interface, it was shown to be displaced by the pNIPAM nanoparticles, and for the highest total component concentration, pNIPAM nanoparticles were predominantly contributing to the reduced oil-water interfacial tension. These findings have implications for the design and performance of fluids that are used to enhance crude oil production from reservoirs, particularly highlighting the aging time and component concentration effects to modify interfacial tensions.

Discontinuous dewetting dynamics of highly viscous droplets on chemically heterogeneous substrates.

HYPOTHESIS: Droplet spreading on heterogeneous (chemical/structural) surfaces has revealed local disturbances that affect the advancing contact line. With droplet dewetting being less studied, we hypothesize that a receding droplet can be perturbed by localized heterogeneity which leads to irregular and discontinuous dewetting of the substrate. EXPERIMENTS: The sessile drop method was used to study droplet dewetting at a wettability boundary. One-half of a hydrophilic surface was hydrophobically modified with either i) methyloctyldichlorosilane or ii) clustered macromolecules. A Lattice Boltzmann method (LBM) simulation was also developed to determine the effect of contact angle hysteresis and boundary conditions on the droplet dynamics. FINDINGS: The two surface treatments were optimized to produce comparable water wetting characteristics. With a negative Gibbs free energy on the hydrophilic-half, the oil droplet receded to the hydrophobic-half. On the silanized surface, the droplet was pinned and the resultant droplet shape was a distorted spherical cap, having receded uniformly on the unmodified surface. Modifying the surface with clustered macromolecules, the droplet receded slightly to form a spherical cap. However, droplet recession was non-uniform and daughter droplets formed near the wettability boundary. The LBM simulation revealed that daughter droplets formed when θR > 164°, with the final droplet shape accurately described by imposing a diffuse wettability boundary condition.

Preliminary Study on Grading Diagnosis of Early Knee Osteoarthritis by Shear Wave Elastography.

Knee osteoarthritis (KOA) is the most common chronic bone joint disease. The WHO points out that KOA has become the fourth most disabling disease in the world, and the main clinical treatment is prevention. At present, the clinical diagnosis of knee osteoarthritis with deformation is mainly made by X-ray and two-dimensional ultrasound, and the preventive treatment effect is not good. Shear wave elastography (SWE) has been widely used in clinical practice for its advantages of noninvasive, simple, rapid, and high accuracy in soft tissue hardness. This study investigates the feasibility of using SWE in the grading diagnosis of KOA and the detection of early skeletal muscle injury. 60 patients were enrolled with unilateral KOA who met the inclusion criteria. Routine scanning and SWE exploration were carried out and compared between the affected and healthy knee joints. The measurements included morphology, damage degree of cartilage, joint effusion, joint synovial thickness, the degree of meniscus convexity, and shear wave speed (SWS) in the tendon attachment area of the quadriceps femoris superior patella, and tendon thickness and SWS between and within groups. The affected was scored according to the ultrasonic characteristics. The correlation between them was analyzed to evaluate the feasibility of SWE in grading the diagnosis of KOA. 57 cases had knee cavity effusion (57/60, 95.0%), 58 cases had knee cartilage injury (58/60, 96.6%), and 35 cases had a lateral process of the medial meniscus (35/60, 53.3%); 30 cases had synovial hyperplasia (30/60, 50%), 21 cases had osteophyte formation (21/60, 35%), and no one had a popliteal cyst. There was no significant difference in tendon thickness between and within groups (p > 0.05), but a significant difference in SWS (p < 0.01); the SWS of the quadriceps femoris tendon is negatively correlated with ultrasound score (r = 0.955, p < 0.01). There is a strong negative correlation between SWS and the degree of KOA. It can be used in the grading diagnosis of KOA to help find more early strain points.

Interfacial behavior of core-shell composite nanoparticles under compression and shear: Influence of polymer shell thickness.

HYPOTHESIS: The mobility of core-shell nanoparticles partitioned at an air-water interface is strongly governed by the compliance of the polymer shell. EXPERIMENTS: The compressional, relaxation and shear responses of two polymer-coated silica nanoparticles (CPs) were studied using a Langmuir trough and needle interfacial shear rheometer, and the corresponding structures of the particle-laden interfaces were visualized using Brewster angle and scanning electron microscopy. FINDINGS: The mobility of CPs partitioned at an air-water interface correlates to the polymer MW. In compression, the CPs40-laden interface (silica nanoparticles coated with 40 kDa PVP) showed distinct gas-liquid-solid phase transitions and when the surface pressure was reduced, the compressed particle-laden interface relaxed to its original state. The compressed-state of the CPs8-laden interface did not relax, and wrinkles in the particle-laden film that had formed in compression remained due to greater adhesion between the compressed particles. The increased mobility of the CPs40-laden interface translated to lower surface shear moduli, with the viscoelastic moduli an order of magnitude or more lower in the CPs40-laden interface than the CPs8-laden interface. Ultimately this contributed to changing the stability of particle-stabilized foams, with less mobile interfaces providing improved foam stability.

Quantum enhanced electro-optic sensor for E-field measurement.

The measurement of intense E-field is a fundamental need in various research areas. An electro-optic (EO) sensor based on common path interferometer (CPI) is widely used due to its better temperature stability and controllability of optical bias. However, the small EO coefficient leads to poor sensitivity. In this paper, a quantum enhanced EO sensor is proposed by replacing the vacuum state in classical one with a squeezed-vacuum state. Theoretical analysis shows that the performance of the quantum enhanced EO sensor, including signal to noise ratio (SNR) and sensitivity, can always beat the classical one due to the noise suppression caused by the squeezed-vacuum state. Experimental results demonstrate that, there is still a 1.12dB quantum enhancement compared with the classical one when the degree of the squeezed-vacuum is 1.60dB. More importantly, except the increase of the EO coefficient or the optical power, the performance of the EO sensor can also be enhanced via quantum light source. Such a quantum enhanced EO sensor could be practically applied for the measurement of intense E-field.

Application of α-amylase as a novel biodemulsifier for destabilizing amphiphilic polymer-flooding produced liquid treatment.

The performance and de-emulsification mechanism of α-amylase, a novel environmental friendly biodemulsifier in petroleum industry, was investigated at room temperature. The effects of α-amylase on the viscosity of amphiphilic polymer solution and de-emulsification rate were studied by changing the concentration of α-amylase, temperature and salinity. Polymer molecular weight, Zeta potential, interfacial film strength and interfacial tension were measured to investigate the de-emulsification mechanism of α-amylase. The results show that α-amylase is an efficient biodemulsifier to increase the de-emulsification rate of amphiphilic polymer emulsions. Hydrolysis of α-amylase to amphiphilic polymers destroys the structure of the amphiphilic polymer, thereby reduces the viscosity and the interfacial film strength of the system. Once de-emulsification is completed, the lower layer, i.e. the emulsified layer, will be clear. Thus, α-amylase can be applied as an effective de-emulsifier for amphiphilic polymer-stabilized O/W emulsion.

Rheinheimera longhuensis sp. nov., isolated from a slightly alkaline lake, and emended description of genus Rheinheimera Brettar et al. 2002.

The bacterial strain LH2-2(T) was isolated from freshwater of Longhu Lake, a slightly alkaline lake (pH 8.8) in north-east China. Cells of strain LH2-2(T) were Gram-staining-negative, non-spore-forming rods, 0.3-0.5 µm wide and 2.0-4.0 µm long. Cells were motile by means of a single polar flagellum. The strain was strictly aerobic and heterotrophic and oxidase- and catalase-positive. Growth occurred at 0-36 °C (optimum, 26-34 °C), pH 6.5-11 (optimum, pH 8.0-8.6) and in the presence of 0-2 % (w/v) NaCl (optimum, 1%). Strain LH2-2(T) contained Q-8 as the major respiratory quinone. The major fatty acids were summed feature 3 (C(16:1)ω7c and/or iso-C(15:0) 2-OH; 21.9%), C(17:1)ω8c (18.9%), C(18:1)ω7c (16.4%) and C(16:0) (12.7%) after growth on marine agar 2216. The DNA G+C content was 47 mol% (T(m)). The 16S rRNA gene and a conserved portion of the gyrB gene were sequenced and used for phylogenetic analyses. Phylogenetic trees based on 16S rRNA gene and gyrB sequences showed that strain LH2-2(T) was associated with the genus Rheinheimera and closely related to the type strains of Rheinheimera species, and showed the highest 16S rRNA gene sequence similarity to Rheinheimera pacifica KMM 1406(T) (97.4%), R. aquimaris SW-353(T) (97.1%) and R. chironomi K19414(T) (96.5%). The DNA-DNA relatedness of strain LH2-2(T) to R. pacifica NBRC 103167(T), R. aquimaris JCM 14331(T) and R. chironomi LMG 23818(T) was 39, 31 and 23%, respectively. Based on these results, it is concluded that strain LH2-2(T) represents a novel species of the genus Rheinheimera, for which the name Rheinheimera longhuensis sp. nov. is proposed. The type strain is LH2-2(T) ( = CGMCC 1.7003(T)  = NBRC 105632(T)). An emended description of the genus Rheinheimera is also provided.

Hydrocarboniphaga daqingensis sp. nov., isolated from a freshwater lake.

A Gram-negative bacterium, designated B2-9(T), was isolated from water of a slightly alkaline lake, Longhu Lake in Daqing, north-east China. Strain B2-9(T) was an aerobic rod, heterotrophic, catalase- and oxidase-positive and motile by means of a single polar flflagellum. The isolate grew well on n-alkanes C(9)-C(17) and weakly on C(6)-C(8), C(18) and C(19). Growth occurred at 10-37 °C (optimum 20-25 °C), at pH 5.5-9.5 (optimum pH 7.0) and with ≤1.0 % (w/v) NaCl. The major fatty acids were C(18 : 1)ω7c (41.4 %), summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c; 18.5 %) and C(16 : 0) (10.9 %). Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain B2-9(T) belonged to the genus Hydrocarboniphaga of the class Gammaproteobacteria and shared 97.0 % 16S rRNA gene sequence similarity with Hydrocarboniphaga effusa AP103(T). DNA-DNA relatedness between strain B2-9(T) and H. effusa DSM 16095(T) was 24 %. The DNA G+C content of strain B2-9(T) was 66 mol%. Strain B2-9(T) is considered to represent a novel species of the genus Hydrocarboniphaga, for which the name Hydrocarboniphaga daqingensis sp. nov. is proposed. The type strain is B2-9(T) (=CGMCC 1.7049(T) =NBRC 104238(T)).

Catellibacterium aquatile sp. nov., isolated from fresh water, and emended description of the genus Catellibacterium Tanaka et al. 2004.

A Gram-negative, rod-shaped, non-pigmented, non-spore-forming bacterial strain that was motile by a single polar flagellum, designated A1-9(T), was isolated from Daqing reservoir in north-east China and its taxonomic position was studied using a polyphasic approach. Strain A1-9(T) was non-halophilic, strictly aerobic and heterotrophic and lacked carotenoids, internal membranes and genes for photosynthesis (puf genes). Strain A1-9(T) grew at 10-40 degrees C (optimum, 25-30 degrees C) and pH 5.5-9.0 (optimum, pH 6.0-6.5) and tolerated up to 1.0 % NaCl (w/v). Neither phototrophic nor fermentative growth was observed. The predominant ubiquinone was Q-10 and the major fatty acid was C(18 : 1) ω 7c (70 %). The DNA G+C content was 64.4 mol% (T(m)). Phylogenetic analyses based on the 16S rRNA gene sequence revealed that strain A1-9(T), together with Catellibacterium nectariphilum AST4(T), formed a deep line within the 'Rhodobacter clade' of the family Rhodobacteraceae and strain A1-9(T) showed 94.2 % 16S rRNA gene sequence similarity to C. nectariphilum AST4(T). On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain A1-9(T) is considered to represent a novel species of the genus Catellibacterium, for which the name Catellibacterium aquatile sp. nov. is proposed. The type strain is A1-9(T) (=CGMCC 1.7029(T) =NBRC 104254(T)).

Algoriphagus aquatilis sp. nov., isolated from a freshwater lake.

A Gram-negative, non-spore-forming, non-motile bacterium, strain A8-7(T), was isolated from fresh water of a slightly alkaline lake, Longhu Lake, in Daqing, north-east China, and its taxonomic position was studied by using a polyphasic approach. Strain A8-7(T) was aerobic, heterotrophic and positive for catalase and oxidase. It grew at 20-37 degrees C (optimum 30 degrees C) and pH 5.5-10.5 (optimum pH 7.5) and in the presence of 0-3 % (w/v) NaCl. It formed pink-pigmented, smooth and circular colonies, 1-2 mm in diameter, on R3A-V agar plates after incubation at 30 degrees C for 3 days. Cells of strain A8-7(T) were rods, 0.2-0.4 mum wide and 1.6-4.0 mum long. The major fatty acids (>10 %) were iso-C(15 : 0) (40.3 %) and summed feature 3 (C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH; 12.1 %). The menaquinone was MK-7. The DNA G+C content was 43 mol% (T(m)). Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain A8-7(T) was phylogenetically related to members of the genus Algoriphagus, with sequence similarities of 92.6-95.2 %, the highest sequence similarity being to the sequence from Algoriphagus mannitolivorans IMSNU 14012(T). On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain A8-7(T) was considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus aquatilis sp. nov. is proposed. The type strain is A8-7(T) (=CGMCC 1.7030(T) =NBRC 104237(T)).

[Microbial diversity in scorpion intestine (Buthus martensii Karsch)].

Scorpion is an important officinal animal, and has a high nutritional value. In this study, the culture-independent and culture-dependent methods were used to investigate the microbial diversity in the scorpion's intestine. Results based on culture-independent method showed the bacteria to be related to alpha, beta, gamma-proteobacteria. Bacteria isolated by the culture-dependent method were high G + C, gram-positive bacteria. The genera Enterobacter, Serratia and Ochrobactrum were detected by both methods. To sum up the results from the two methods, the bacteria in scorpion intestine belong to 23 genera, which are Enterobacter, Serratia, Pseudomonas, Acinetobacter, Aeromonas, Citrobacter, Pedobacter, Delftia, Ralstonia, Ochrobactrum, Sphingomonas, Exiguobacterium, Gordonia, Nocardia, Rhodococcus, Janibacte, Kocuria, Micrococcus, Agromyces, Microbacterium, Agrococcus, Deinococcus, Ornithinimicrobium, and some uncultured species. The two methods have both advantages and shortcomings. However, when used simultaneously, they complement each other.