Conduction-Dominated Cryomesh for Organism Vitrification.

Vitrification-based cryopreservation is a promising approach to achieving long-term storage of biological systems for maintaining biodiversity, healthcare, and sustainable food production. Using the "cryomesh" system achieves rapid cooling and rewarming of biomaterials, but further improvement in cooling rates is needed to increase biosystem viability and the ability to cryopreserve new biosystems. Improved cooling rates and viability are possible by enabling conductive cooling through cryomesh. Conduction-dominated cryomesh improves cooling rates from twofold to tenfold (i.e., 0.24 to 1.2 × 105  °C min-1 ) in a variety of biosystems. Higher thermal conductivity, smaller mesh wire diameter and pore size, and minimizing the nitrogen vapor barrier (e.g., vertical plunging in liquid nitrogen) are key parameters to achieving improved vitrification. Conduction-dominated cryomesh successfully vitrifies coral larvae, Drosophila embryos, and zebrafish embryos with improved outcomes. Not only a theoretical foundation for improved vitrification in µm to mm biosystems but also the capability to scale up for biorepositories and/or agricultural, aquaculture, or scientific use are demonstrated.

Hydrophilic reentrant SLIPS enabled flow separation for rapid water harvesting.

Water harvesting from air is desired for decentralized water supply wherever water is needed. When water vapor is condensed as droplets on a surface the unremoved droplets act as thermal barriers. A surface that can provide continual droplet-free areas for nucleation is favorable for condensation water harvesting. Here, we report a flow-separation condensation mode on a hydrophilic reentrant slippery liquid-infused porous surface (SLIPS) that rapidly removes droplets with diameters above 50 µm. The slippery reentrant channels lock the liquid columns inside and transport them to the end of each channel. We demonstrate that the liquid columns can harvest the droplets on top of the hydrophilic reentrant SLIPS at a high droplet removal frequency of 130 Hz/mm2. The sustainable flow separation without flooding increases the water harvesting rate by 110% compared to the state-of-the-art hydrophilic flat SLIPS. Such a flow-separation condensation approach paves a way for water harvesting.

Quasi-Liquid Surfaces for Sustainable High-Performance Steam Condensation.

Sustainable high-performance steam condensation is critical to reducing the size, weight, and cost of water and energy systems. It is well-known that dropwise condensation can provide a significantly higher heat-transfer coefficient than filmwise condensation. Tremendous efforts have been spent to promote dropwise condensation by achieving a nonwetting state on superhydrophobic surfaces and a slippery state on liquid-infused surfaces, but these surfaces suffer from severe durability challenges. Here, we report sustainable high-performance dropwise condensation of steam on newly developed durable quasi-liquid surfaces, which are easily made by chemically bonding quasi-liquid polymer molecules on solid substrates. As a result, the solid/water interface is changed to a quasi-liquid/water interface with minimal adhesion and extraordinary durability. The quasi-liquid surface with ultralow contact angle hysteresis down to 1° showed a heat-transfer coefficient up to 70 and 380% higher than those on conventional hydrophobic and hydrophilic surfaces, respectively. Furthermore, we demonstrated that the quasi-liquid coating exhibited a sustainable heat-transfer coefficient of 71 kW/(m2 K) at a heat flux of 420 kW/m2 under a prolonged period of 39 h in continuous steam condensation. Such a quasi-liquid surface has the potential to sustain high-performance dropwise condensation of steam and address the long-standing durability challenge in the field.

Passive Removal of Highly Wetting Liquids and Ice on Quasi-Liquid Surfaces.

Surfaces with ultralow adhesion to liquids and solids have attracted broad interests in both fundamental studies and engineering applications from passive removal of highly wetting liquids and water harvesting to anti-/de-icing. The current state-of-the-art superomniphobic surfaces (rely on air lubricant) and liquid-infused surfaces (rely on liquid lubricant) suffer from severe issues for liquid repellency and ice removal: air/liquid lubricant loss or topography damage. Here, we create a durable quasi-liquid surface by tethering flexible polymer on various solid substrates. The untethered end of the polymer has mobile chains that behave like a liquid layer and greatly reduce the interfacial adhesion between the surface and foreign liquids/solids. Such a quasi-liquid surface with a 30.1 nm flexible polymer layer shows ultralow contact angle hysteresis (≤1.0°) to liquids regardless of their surface tensions. The highly wetting perfluorinated liquids like FC72 and Krytox101, as well as complex fluids like urine and crude oil, can be repelled from the surface. Moreover, wind can remove accreted ice from the surface in harsh conditions due to the negligible ice adhesion. We have demonstrated that the quasi-liquid surface shows robust performances in repelling highly wetting liquids, harvesting water, and removing ice, respectively.

[Establishment of standardized method for pulsed-field gel electrophoresis on Leptospira interrogans and analysis on their patterns].

OBJECTIVE: To establish a standardized operation procedure for pulsed-field gel electrophoresis (PFGE) on Leptospira interrogans as well as a figure digital database to develop the Chinese representative reference strains. METHODS: Under the characteristics of strains and referring to the other SOPs of PFGE on pathogens provided by CDC and PulseNet Asia Pacific, genomic chromosome DNA purification, restriction endonuclease digestion and the parameters for running PFGE were optimized. RESULTS: Not I digestion patterns of leptospiral genome for the Chinese representative strains were established and partial isolates of serogroup icterohaemorrhagiae from the leptospirosis surveillance in Sichuan and Anhui provinces were analyzed by PFGE. Results showed that each of all the 15 Chinese representative strains had a unique pattern. 91.67% (22/24) of the 24 isolates identified as serogroup icterohaemorrhagiae matched to the map of the reference strain 56601 (serogroup icterohaemorrhagiae serovar lai). CONCLUSION: The PFGE figures were clear with high resolution and the fragments were equally distributed by this standardized operating procedure so as to reveal the molecular-genetic characteristics of Leptospira interrogans. The patterns had high relativity with the serological identification and seemed to be very important for genetic analysis of strains in studying the outbreak of leptospirosis.

[Study on the location of membrane and detection of antibody in the sera of genus-specific antigen LipL41s in patients with Leptospira interrogans].

OBJECTIVE: To determine the location on outer envelope and natural antibody response and types of genus-specific lipoprotein antigen LipL41s in patients with Leptospira interrogans. METHODS: Microscope agglutination test (MAT) was used to examine leptospirosis patients' serum samples from Sichuan area, China. Ni-NTA affinity chromatography was performed to extract the target recombinant rLipL41/1 and rLipL41/2 products that expressed under inducement of IPTG. Western blot assay was performed to detect the immunoreactivity between the sera from the patients infected with different serogroups of L. interrogans and rLipL41s. Immune aurosol electron microscopy was selected to locate the position of LipL41s on leptospiral envelope. ELISA based on rLipL41s was established to confirm the level and types of specific antibody. RESULTS: L. interrogans serogroup icterohaemorrhagiae remained to be the most dominant leptospiral serogroup in Sichuan area. All the sera from patients infected with different serogroups of L. interrogans could efficiently recognize the LipL41s which were the protein molecular that located on the external surface of leptospiral envelope. In the 156 serum samples from MAT positive leptospirosis patients, the positive rates for rLipL41/1 or rLipL41/2 specific IgM appeared to be 84.6%-87.8% and 78.2%-83.3%, respectively, while for rLipL41/1 or rLipL41/2 specific IgG they were 69.2%-81.4% and 75.0%-80.1%, respectively. CONCLUSION: LipL41s were the leptospiral superficial protein antigen of L. interrogans. Both the LipL41/1 and LipL41/2 could induce serum antibodies IgM and IgG with extensive antigenic-cross reaction during natural infection of L. interrogans in general populations. Hence, rLipL41/1 or rLipL41/2 could be used as the antigen candidate for developing universal genetic engineering vaccine and detection kit.

[Membrane location and naturally antibody responses of genus-specific antigen OmpL1s of Leptospira interrogans].

The major aim of this study is to determine the location on outer envelope of the genus-specific antigen OmpL1s of Leptospira interrogans, and the inducement of naturally antibody response and types of the antigen, which will offer the evidences to use OmpL1s as the antigen candidate for developing universal genetic engineering vaccine and detection kit. The serum samples from 156 leptospirosis patients in Sichuan area were detected using microscope agglutination test (MAT). By using PCR plus nucleotide sequence analysis, the genotypes of the dominant L. interrogans serogroups in China were demonstrated. Routine genetic engineering technique was applied to construct the prokaryotic expression systems of genotypes ompL1/1 and ompL1/2, and Ni-NTA affinity chromatography was performed to extract the target recombinant products rOmpL1/1 and rOmpL1/2. Immune aurosol electron microscopy was selected to locate the position of OmpL1s on leptospiral envelope. ELISAs based on rOmpL1s were established to confirm the level and types of specific antibody. The results indicated that L. interrogans serogroup Icterohaemorrhagiae remains to be the most important dominant leptospiral serogroup in Sichuan area. There are two ompL1 genotypes of ompL1/1 and ompL1/2 in the dominant leptospiral serogroup in China. And remarkable differences of the nucleotide and putative amino acid sequence similarities between the two genotypes are present. OmpL1s are the protein molecular that located on the external surface of leptospiral envelope. In the 156 cases of leptospirosis patients' serum samples using different dilutions, the positive rates for rOmpL1/1 or rOmpL1/2 specific IgM are 67.9%-79.5% and 75.0%-75.6%, while for for rOmpL1/1 or rOmpL1/2 specific IgG are 71.8%-79.5% and 75.0%-76.9%, respectively. All the results mentioned above lead to the conclusions that OmpL1s is the leptospiral genus-specific superficial protein antigen of L. interrogans and both rOmpL1/1 and rOmpL1/2 can induce humoral response in individuals naturally infected with L. interrogans as well as produce two serum antibodies IgM and IgG with extensive antigenic-cross reaction. Therefore, rOmpL1/1 and rOmpL1/2 can be used as the antigen candidate for developing universal genetic engineering vaccine and detection kit.