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Polyhydroxyalkanoates (PHAs) are green and sustainable bioplastics that could replace petrochemical synthetic plastics without posing environmental threats to living organisms. In addition, sustainable PHA production could be achieved using marine photosynthetic purple nonsulfur bacteria (PNSBs) that utilize natural seawater, sunlight, carbon dioxide gas, and nitrogen gas for growth. However, PHA production using marine photosynthetic PNSBs has not been economically feasible yet due to its high cost and low productivity. In this work, strain improvement, using genome-wide mutagenesis coupled with high-throughput screening via fluorescence-activated cell sorting, we were able to create Rhodovulum sulfidophilum mutants with enhanced volumetric PHA productivity, with an up to 1.7-fold increase. The best selected mutants (E6 and E6M4) reached the stationary growth phase 1 day faster and accumulated the maximum PHA content 2 days faster than the wild type. Maximizing volumetric PHA productivity before the stationary growth phase is indeed an additional advantage for R. sulfidophilum as a growth-associated PHA producer.

The low-cycle fatigue (LCF) deformation mechanism and fatigue life of an Al-12Si alloy were investigated at different temperatures and strain rates. With increasing temperature, the fatigue life increases at first and then reduces, which is derived from the deformation mechanism. At the lower temperatures, the primary Si cracking induced by piling-up of dislocations dominates fatigue damage behaviors. Both of increasing temperature and reducing the strain-rate can restrain the phase cracking, thus increase fatigue life. However, with further increasing temperature, the micro-scale void caused by dislocation annihilation dominates the phase debonding behavior, leading to the decrease of fatigue life.

Significance Imaging flow cytometry is a powerful tool for analyzing every single cell in a large heterogeneous population but relies on fluorescent labeling, which comes with cytotoxicity, nonspecific binding, and interference with natural cellular functions. This paper presents label-free multicolor chemical imaging flow cytometry based on stimulated Raman scattering (SRS), a highly sensitive method of molecular vibrational spectroscopy. With the help of deep learning, it demonstrates high-precision characterization and classification of microalgal cells and cancer cells without the need for fluorescent labeling., Combining the strength of flow cytometry with fluorescence imaging and digital image analysis, imaging flow cytometry is a powerful tool in diverse fields including cancer biology, immunology, drug discovery, microbiology, and metabolic engineering. It enables measurements and statistical analyses of chemical, structural, and morphological phenotypes of numerous living cells to provide systematic insights into biological processes. However, its utility is constrained by its requirement of fluorescent labeling for phenotyping. Here we present label-free chemical imaging flow cytometry to overcome the issue. It builds on a pulse pair-resolved wavelength-switchable Stokes laser for the fastest-to-date multicolor stimulated Raman scattering (SRS) microscopy of fast-flowing cells on a 3D acoustic focusing microfluidic chip, enabling an unprecedented throughput of up to ∼140 cells/s. To show its broad utility, we use the SRS imaging flow cytometry with the aid of deep learning to study the metabolic heterogeneity of microalgal cells and perform marker-free cancer detection in blood.

The high-performance Al12Si4Cu3NiMg alloy with massive transition elements has been developed recently for piston of diesel engines. The influences of microstructures on the tensile and low-cycle fatigue (LCF) behaviors were investigated with conventional and in situ testing technologies in this study. Upon the tensile loading, the microcracks initiate from the primary Si near the surface when the tensile stress reaches approximately 280 MPa (close to the tensile strength); then, the microcracks grow rapidly through eutectic Si and intermetallics (Al3CuNi) for the gravity casting (GC) alloy. With regard to the LCF, the microcracks initiate from the shrinkage pores regularly because of the localization of fatigue damage in the GC alloy. The shrinkage pores, usually accompanied by the brittle intermetallics (Al3CuNi), typically exhibit more complex geometry. The lamellar Al3CuNi provides a preferred path for the crack propagation after fatigue crack initiation. The ultrasonic melt treatment (UT) was used to optimize the microstructures and reduce casting defects (shrinkage pores), thereby resulting in improvement in tensile and LCF properties. For the UT alloy (pore-free), the microcrack initiates from some coarser primary Si rather than from the shrinkage pores because of the accumulation of micro-scale plastic deformation. Furthermore, higher resistance of crack propagation can also be realized with refinement of microstructures in the UT alloy. Increase in crack initiation and propagation resistances is the main reason for improvement in the LCF life of the UT alloy.

A metamaterial analogy of tunable electromagnetically induced transparency (EIT) is theoretically investigated in terahertz regime. The proposed metamaterial consists of vertical gold strips and horizontal graphene wires, which perform as bright elements and dark elements, respectively. The EIT-like phenomenon can be induced by bright–dark mode coupling on condition of structural lateral displacement. Numerical result reveals that the EIT-like effect remains noticeable with a wide range of incidence polarization angles. Most importantly, by manipulating gate voltages, the EIT window can be dynamically controlled without refabricating the structure. The amplitude modulation depth can reach 81%, 79%, and 68% respectively at three characteristic frequencies as Fermi energy changes in the scope of 0.8–1.0 eV. Furthermore, a sensitivity of 0.95 THz per refractive index unit (RIU) is realized varying the refractive index in the surrounding medium. This structure provides potential applications for detectors, sensors, and modulators.

Dendritic metal chalcogenide (HgS, CdS and PbS) single crystals have been prepared via facile and mild solvothermal process in water or ethanol/water systems. SEM and TEM observations show that HgS and CdS dendrites exhibit whole or part of the two-dimensional (2D) hexagonal snowflake spatial pattern while PbS exhibits whole or part of the three-dimensional (3D) octahedral star-like morphology. Selected area electron diffusion (SAED) and HRTEM show that all of these dendrites are single crystals whose shape evolution is closely related to their intrinsic crystal symmetries. The factors influencing the evolution of the crystal morphology, i.e. reactant molar ratio, solvent, sulfur source, reaction time and temperature have been investigated. Two dimensional six-fold symmetrical HgS and CdS dentrites and 3D four-fold symmetrical PbS dentrite have been fabricated by a facile solvothermal method. The crystal evolution process has been investigated.

Covellite copper sulfide submicron crystals in the shapes of ball-like, rodlike, and chrysanthemum-like architectures congregated from nanoslices with thickness of 20 to 100 nm have been prepared by a hydrothermal method without using any surfactant and characterized by X-ray diffraction, energy-dispersive X-ray spectrometer (EDX), UV−vis optical absorption spectra, and electron-microscopy techniques. A systematic investigation has been carried out to understand the factors influencing the evolution of the crystal morphology which was found to be predominant by the reactant molar ratio (Tu:Cu(NO3)2, Tu = thiourea), the hydrothermal reaction time, and the temperature. Possible crystal growth processes are also discussed.

The self assembly of AgX with the sulfur-containing multidentate ligand α,α′-bis(8-thioquinoline)-m-xylene (m-XYTQ) affords two isomorphous complexes [Ag(m-XYTQ)]nXn (X=ClO4 1; X=BF4 2). Single crystal X-ray analyses revealed the complexes to contain linear cationic chains of [Ag(m-XYTQ)]nn+ in helical arrangement and the anions are discrete. Intramolecular π⋯π stackings pack the asymmetric units [Ag(m-XYTQ)] in shelves-like arrays while interchain π⋯π interactions between racemic chains constructed the 2D network. The key to helix formation is the folding at the sulfur sites of the spacer xylylene in the ligand. The complexes were also characterized by 1H NMR and IR.

The trans-oxamidato dicopper(II) "synthons", [Cu 2 (trans-L)] 2+ (L= oxen, oxpn, oxap, and oxpy) have been used as construction units when further connected by a second bridging ligand L′ (spacer) to fabricate supramolecular architectures via covalent and hydrogen bonding interactions. The structural topologies of the polymeric networks contained by these compounds depend mainly on the coordination modes of the spacers. When the spacers are 2-connectors bridging two synthons, the resulting compounds usually contain 1-D infinite chains, while 3- or 4-connector provides compounds containing 2-D extended coordination networks. The hydrogen bonds, in which the oxamidate, the spacer, and the water molecules are involved, are prevalent and the predominant intermolecular interactions. Compared with the polymeric networks constructed via covalent bonding interactions between synthons and spacers, the structural topologies of the 3-D supramolecular architectures fabricated via hydrogen bonding interactions are mor...

The reaction of M2+ (M=Co or Ni) with K2(i-mnt) and phosphine forms chelated ternary coordination compounds (1)-(4). The crystal structures of Ni(i-mnt)(dppmSe) (1) (in the presence of Se) and (“Bu4N”)[Co(i-mnt)2(PBu n 2] (2) were determined by single-crystal X-ray diffraction analyses; (1) crystallizes in the monoclinic space group P21/n with a = 12.002(3), b = 19.568(11), c = 12.456(5) A, β = 92.22(3)°, V = 2923.4 A3, Z=2, R(Rw ) = 0.051 (0.062). The distorted, square planar Ni atom forms two individual chelate rings with the two bidentate ligands. Complex (2) crystallizes in space group P 1 with a = 10.682(2), b = 28.496(6), c = 9.959(2) A, α = 91.31(2), β = 97.71(2), γ = 83.68(2)°, V=2986(1)A3, Z=2, R (Rw ) = 0.060 (0.072). The octahedral Co(III) ion in (2) has an elongated structure with two monodentatc phosphines in axial positions and i-mnt groups chelating in the equatorial plane. Spectroscopic characterization was performed where appropriate.

The title compound (Et4N)[Mn(MP-MP)2] (1) was obtained by air oxidation of an acetonitrile solution of MnCl2-4H2O and Na2MP. The structure of 1 was determined by single crystal X-ray diffraction methods. Crystal data: C32H36MnNO4S4, monoclinic, P21/c, a = 9.598(3), b = 16.845(3), c = 10.702(3) A, β = 111.20(1)°, V= 1613.1 A3, Z = 2; Mr = 681.84; d x = 1.40g cm−3 F(000) = 712; μ = 6.8cm−1, crystal dimensions 0.40 × 0.20 × 0.20 mm3. The Mn atom is octahedrally and symmetrically coordinated by two MP-MP2- ligands, each providing two phenolate-oxygen and one disulfide-sulfur atoms to form a terdentate. The presence of an S-S bond is revealed by the distance of 2.093 A, which constitutes the first disulphide chelated to the Mn(III) ion. The paramagnetic nature of the high spin Mn(d4) ion is reflected in a value of μcff of 4.83 μB and broad 1H NMR absorptions at 23 ∼ 25ppm and –12∼-17ppm.

A novel polynuclear Mo−Cu cluster compound (Et4N)4[MoS4Cu10Cl12] has been synthesized by the reaction of (NH4)2[MoS4], Et4NCl, and CuCl in acac/DMSO. The reaction mechanism has been monitored by dynamic 95Mo NMR spectra. X-ray single-crystal diffraction analysis reveals that the anion structure consists of a central MoS4 moiety, an octahedral Cu6 array and a tetrahedral Cu4 array, representing the addition of 10 copper atoms across the six edges and four faces of MoS4 tetrahedron. The average Mo−Cu and Mo−S distances are 2.708(8) and 2.238(7) A, respectively.

0.8649 (3) 0.5317 (2) 0.0601 (9) 0.8705 (3) 0.5823 (3) 0.0764 (12) 0.7908 (3) 0.6254 (3) 0.0730 (11) 0.7059 (3) 0.6178 (2) 0.0613 (9) 0.6968 (2) 0.5686 (2) 0.0487 (8) 0.8953 (2) 0.4052 (2) 0.0492 (8) 0.9648 (2) 0.4486 (3) 0.0568 (9) 1.0454 (3) 0.4002 (3) 0.0734 (12) 1.0583 (3) 0.3143 (4) 0.0797 (13) 0.9927 (3) 0.2717 (3) 0.0733 (11) 0.9117 (3) 0.3179 (2) 0.0590 (9) 0.7715 (3) 0.3957 (2) 0.0598 (9) 0.5997 (2) 0.5647 (2) 0.0643 (10) 0.9598 (3) 0.5425 (3) 0.0778 (12)

A new complex [Ag4(μ2-S-mbo)4(dppp)4](1) is obtained from the reaction of AgBF4 and Hmbo(2-mercaptobenzoxazole) with the participation of dppp(bis(diphenylphosphino) propane). Single crystal X-ray diffraction analysis shows that it is discrete neutral molecule and composed of two asymmetrical moieties. Four Ag atoms in each molecule are completely coplanar and of similar environment. The ligands Hmbo and dppp in complex 1 bridge two Ag atoms through “μ2-S-mbo” and P atoms in two ends, respectively. The possible mechanism of the reaction is provided, and the sequence of adding materials and the length of backbone (CH2)n in diphosphine play an important role in the results of the reactions.

[Pd(C 6 H 5 S) 2 {(C 6 H 5 ) 2 PCH 2 CH 2 P(C 6 H 5 ) 2 }] cristallise dans C2/c avec a=14,320, b=16,383, c=14,295 A, β=93,41 o , Z=4; affinement jusqu'a R=0,0269. La molecule possede un axe binaire passant par Pd et par les points medians de S−S et de P−P avec ces cinq atomes essentiellement plans