How to better focus waves by considering symmetry and information loss

Lou, Kai,Granick, Steve,Amblard, Franç,ois National Academy of Sciences 2018 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.115 No.26

<▼1><P><B>Significance</B></P><P>With applications from electromagnetic communications, to biological and astronomical imaging, to lithography and warfare, waves transmit information, and optimal wave focusing is essential. Here we demonstrate the need to amend the belief that spherical or cylindrical wavefronts necessarily focus at their center of curvature. Instead the effective focus shifts toward the source with decreasing apertures, producing astigmatism when, as increasingly shown for modern applications, the wavefronts are not axially symmetric. This leads to significant degradation of axial resolution in nonaxisymmetric light-focusing applications. These conclusions, derived from diffraction theory and validated by application to optical bioimaging, offer a general strategy to likewise improve the resolution of virtually any other wave-based application whose efficacy depends on focusing energy to points or lines.</P></▼1><▼2><P>We amend the general belief that waves with extended spherical wavefront focus at their center of curvature. Instead, when the spherical symmetry of waves is broken by propagating them through a finite aperture along an average direction, the forward/backward symmetry is broken and the focal volume shifts its center backward along that direction. The extent of this focal shift increases as smaller apertures are used, up to the point that the nominal focal plane is out of focus. Furthermore, the loss of axial symmetry with noncircular apertures causes distinct focal shifts in distinct axial planes, and the resulting astigmatism possibly degrades the axial focusing resolution. Using experiments and simulations, focal shift with noncircular apertures is described for classical and temporal focusing. The usefulness of these conclusions to improve imaging resolution is demonstrated in a high-resolution optical microscopy application, namely line-temporal focusing microscopy. These conclusions follow from fundamental symmetries of the wave geometry and matter for an increasing number of emerging optical techniques. This work offers a general framework and strategy to understand and improve virtually any wave-based application whose efficacy depends on optimal focusing and may be helpful when information is transmitted by waves in applications from electromagnetic communications, to biological and astronomical imaging, to lithography and even warfare.</P></▼2>

Deep line-temporal focusing with high axial resolution and a large field-of-view using intracavity control and incoherent pulse shaping

Lou, Kai,Wang, Bo,Jee, Ah-Young,Granick, Steve,Amblard, Franç,ois The Optical Society 2018 Optics letters Vol.43 No.20

Periosteum-inspired in situ CaP generated nanocomposite hydrogels with strong bone adhesion and superior stretchability for accelerated distraction osteogenesis

Lou Tengfei,Chen Kai,Luo Qiyu,Liu Changsheng,Yuan Yuan,Fan Cunyi 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Distraction osteogenesis (DO) is an efficacious but lengthy procedure to reconstruct segmental bone defects under the principle of tension-stress, during which the periosteum-mediated mechanical stimulation plays a pivotal role. Inspired by the dynamic process of DO and the mechanical stimulation of periosteum, a new design of bionic periosteum was developed to simulate the mechanical transduction of natural periosteum for the application in DO procedure.In this study, an injectable organic-inorganic hybrid hydrogel was developed based on a novel combination of the PEGylated poly (glycerol sebacate) (PEGS) polymer network and in situ formed CaP nanoparticles (ICPNs). Rat bone marrow mesenchymal stem cells (rBMSCs) and human umbilical vein endothelial cells (HUVECs) were cultured and tested in vitro to evaluate biocompatibility, cell adhesion, proliferation, and pro-osteogenic and pro-angiogenic activity. In vivo experiments were conducted in the rat tibial model of distraction osteogenesis.The developed nanocomposite hydrogels exhibited excellent injectability, robust bone adhesion, superior stretchability, and enhanced osteogenic activity. The results of in vitro and in vivo studies showed that PEGS/ICPN hydrogels could promote new bone formation and mineralization during the dynamic distraction process through the synergistic effects of angiogenesis and osteogenesis.This periosteum-inspired nanocomposite hydrogel represents a mechanobiology approach for effectively restoring large bone defects through the dynamic DO process.

Two-dimensional lamellar phosphogypsum/polyethylene glycol composite PCM: Fabrication and characterization

Jinfen Lou,Kai Zhang,Shuhao Qin,Yang Lei,Yufei Liu,Min He,Jie Yu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.113 No.-

In this work, a nanocomposite phase change material (PCM) has been designed by combining twodimensionallamellar anhydrous calcium sulfate with polyethylene glycol (PEG). We report a facile strategyto controllably fabricate two-dimensional lamellar anhydrous calcium sulfate (LAH) with the averagethickness of 28.63 nm from phosphogypsum (PG) through ethylenediamine tetraacetic acid disodium(Na2EDTA) induction in glycerol and ethylene glycol solutions at 98 C. The obtained 2D lamellarCaSO4 was a slit-type mesoporous material stacked by the nanosheet of calcium sulfate. It has a specificsurface area of 70.02 m2/g, which is 10 times larger than phosphogypsum. Na2EDTA acts as a crystalhabit-directing agent to regulate crystal morphology through nonclassical nanoparticle-mediated crystallizationprocesses, resulting in the crystalline morphology tending to be lamellar. Lamellar anhydrouscalcium sulfate phase change composites (LAHPCMs) were prepared with 2D lamellar anhydrous nano-CaSO4 and polyethylene glycol (PEG). The LAHPCMs had a high latent heat storage capacity (92.99 J/g). Lamellar anhydrous calcium sulfate phase change composites have good thermal stability and durability,structure stability, and good liquid leakage resistance. These results provide the possibility for phosphogypsumto be used for energy storage and thermal insulation.

Polysufonamide/Stainless Steel Woven Fabrics: Manufacturing Techniques, Flame Retardance and Electromagnetic Shielding Effectiveness

Hao-Kai Peng,YanTing Wang,Ting-Ting Li,Ching-Wen Lou,XiaoXiao Wang,Jia-Horng Lin 한국섬유공학회 2020 Fibers and polymers Vol.21 No.4

In order to make conductive woven fabrics with electromagnetic shielding effectiveness (EMSE) and flameretardance, polysufonamide (PSA)/stainless steel (SS) core yarn are used as the weft yarns and PSA yarns are used as thewarp yarns. The conductive woven fabrics are denoted as SS-60, SS-80, SS-100, SS-120, and SS-140 according to the twistcounts of the core yarn, and evaluated in terms of mechanical properties, flame retardance, surface resistivity. The test resultsshow that the best twist of the core yarn is 120 turns/10 cm. SS-60 has the maximum burnt length, while SS-140 has theminimum burnt length. Moreover, the surface resistivity of the PSA/SS woven fabrics is proportional to the twist counts, andthe surface resistivity along the warp direction is higher than that along the weft direction. Changing the fabric laminationangle can form a complete shielding network, and the EMSE is significantly increased. For SS-80, SS-100, and SS-120,when they are composed of 4-6 layers with lamination angles of 0 o/45 o/90 o/-45 o/0 o/45 o and 0 o/90 o/0 o/90 o/0 o/90 o, theEMSE is above 40 dB and the shielding effect is above 99.99 % against the incident waves at 2000-3000 MHz. Specifically,SS-120 has the maximum EMSE of 64 dB against incident waves at 2844 MHz.

Effect of Dietary Concentrate:forage Ratios and Undegraded Dietary Protein on Nitrogen Balance and Urinary Excretion of Purine Derivatives in Dorper×thin-tailed Han Crossbred Lambs

Ma, Tao,Deng, Kai-Dong,Tu, Yan,Jiang, Cheng-Gang,Zhang, Nai-Feng,Li, Yan-Ling,Si, Bing-Wen,Lou, Can,Diao, Qi-Yu Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.2

This study aimed to investigate dietary concentrate:forage ratios (C:F) and undegraded dietary protein (UDP) on nitrogen balance and urinary excretion of purine derivatives (PD) in lambs. Four Dorper${\times}$thin-tailed Han crossbred castrated lambs with $62.3{\pm}1.9$ kg body weight at 10 months of age were randomly assigned to four dietary treatments in a $2{\times}2$ factorial arrangement of two levels of C:F (40:60 and 60:40) and two levels of UDP (35% and 50% of CP), according to a complete $4{\times}4$ Latin-square design. Each experimental period lasted for 19 d. After a 7-d adaptation period, lambs were moved into individual metabolism crates for 12 d including 7 d of adaption and 5 d of metabolism trial. During the metabolism trial, total urine was collected for 24 h and spot urine samples were also collected at different times. Urinary PD was measured using a colorimetric method and creatinine was measured using an automated analyzer. Intake of dry matter (DM) (p<0.01) and organic matter (OM) (p<0.01) increased as the level of UDP decreased. Fecal N was not affected by dietary treatment (p>0.05) while urinary N increased as the level of UDP decreased (p<0.05), but decreased as dietary C:F increased (p<0.05). Nitrogen retention increased as dietary C:F increased (p<0.05). As dietary C:F increased, urinary excretion of PD increased (p<0.05), but was not affected by dietary UDP (p>0.05) or interaction between dietary treatments (p>0.05). Daily excretion of creatinine was not affected by dietary treatments (p<0.05), with an average value of $0.334{\times}0.005$ mmol/kg $BW^{0.75}$. A linear correlation was found between total PD excretion and PDC index ($R^2$ = 0.93). Concentrations of creatinine and PDC index in spot urine were unaffected by sampling time (p>0.05) and a good correlation was found between the PDC index (average value of three times) of spot urine and daily excretion of PD ($R^2$ = 0.88). These results suggest that for animals fed ad libitum, the PDC index in spot urine is effective to predict daily excretion of PD. In order to improve the accuracy of the spot sampling technique, an appropriate lag phase between the time of feeding and sampling should be determined so that the sampling time can coincide with the peak concentration of PD in the urine.

Nanoparticle puzzles and research opportunities that go beyond state of the art

Jee, Ah-Young,Lou, Kai,Jang, Hyun-Sook,Nagamanasa, K. Hima,Granick, Steve The Royal Society of Chemistry 2016 Faraday discussions Vol.186 No.-

<P>We present an overview of current progress and research challenges in the field of nanoparticle assembly, touching on the following topics: (1) historical perspective; (2) consideration of what is a nanoparticle; (3) contrast between nanoparticle self-assembly and top-down construction; (4) opportunities for nanoparticles with more intelligent sub-structures; (5) opportunities for nanoparticle systems cued to interact subtly in space and time. In this personal and subjective account, certain holy grails for nanoparticle science and technology are identified.</P>

Illumina-based analysis of bacterial diversity related to halophytes Salicornia europaea and Sueada aralocaspica

Ying-wu Shi,Kai Lou,Chun Li,Lei Wang,Zhen-yong Zhao,Shuai Zhao,Chang-yan Tian 한국미생물학회 2015 The journal of microbiology Vol.53 No.10

We used Illumina-based 16S rRNA V3 amplicon pyrosequencing to investigate the community structure of soil bacteria from the rhizosphere surrounding Salicornia europaea, and endophytic bacteria living in Salicornia europaea plants and Sueada aralocaspica seeds growing at the Fukang Desert Ecosystem Observation and Experimental Station (FDEOES) in Xinjiang Province, China, using an Illumina genome analyzer. A total of 89.23 M effective sequences of the 16S rRNA gene V3 region were obtained from the two halophyte species. These sequences revealed a number of operational taxonomic units (OTUs) in the halophytes. There were between 22–2,206 OTUs in the halophyte plant sample, at the 3% cutoff level, and a sequencing depth of 30,000 sequences. We identified 25 different phyla, 39 classes and 141 genera from the resulting 134,435 sequences. The most dominant phylum in all the samples was Proteobacteria (41.61%–99.26%; average, 43.30%). The other large phyla were Firmicutes (0%– 7.19%; average, 1.15%), Bacteroidetes (0%–1.64%; average, 0.44%) and Actinobacteria (0%–0.46%; average, 0.24%). This result suggested that the diversity of bacteria is abundant in the rhizosphere soil, while the diversity of bacteria was poor within Salicornia europaea plant samples. To the extent of our knowledge, this study is the first to characterize and compare the endophytic bacteria found within different halophytic plant species roots using PCR-based Illumina pyrosequencing method.

Scrutinizing evidence of no dilatancy upon stick–slip of confined fluids

Jee, Ah-Young,Lou, Kai,Granick, Steve National Academy of Sciences 2015 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.112 No.36

Kocuria halotolerans sp. nov., an actinobacterium isolated from a saline soil in China.

Tang, Shu-Kun,Wang, Yun,Lou, Kai,Mao, Pei-Hong,Xu, Li-Hua,Jiang, Cheng-Lin,Kim, Chang-Jin,Li, Wen-Jun Society for General Microbiology 2009 International journal of systematic and evolutiona Vol.59 No.6

<P>A Gram-positive actinobacterium, designated strain YIM 90716(T), was isolated from a saline soil sample collected from Ganjiahu Suosuo Forest National Nature Reserve in Xinjiang Province, north-west China. The new isolate contained lysine, glutamic acid and alanine with peptidoglycan type Lys-Ala(3) (variation A3alpha). The major phospholipids were phosphatidylglycerol and diphosphatidylglycerol. The predominant menaqinone was MK-7(H(2)). The major fatty acids were anteiso-C(15 : 0), iso-C(16 : 0) and anteiso-C(17 : 0). The DNA G+C content of strain YIM 90716(T) was 68.0 mol%. Chemotaxonomic properties supported the affiliation of strain YIM 90716(T) to the genus Kocuria. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the organism was related most closely to Kocuria kristinae DSM 20032(T) (96.8 % similarity) and showed lower levels of 16S rRNA gene similarity (<96.5 %) with the type strains of other species of the genus Kocuria. The results of fatty acid analysis and physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain YIM 90716(T) from its closest relatives. On the basis of data from the present polyphasic study, strain YIM 90716(T) is considered to represent a novel species of the genus Kocuria, for which the name Kocuria halotolerans sp. nov. is proposed. The type strain is YIM 90716(T) (=DSM 18442(T)=KCTC 19172(T)=CCTCC AB 206069(T)).</P>