Interfacial Thermal Fluctuations Stabilize Bulk Nanobubbles.

Consensus on bulk nanobubble stability remains elusive, despite accepted indirect evidence for longevity. We develop a nanobubble evolution model by incorporating thermal capillary wave theory that reveals that dense nanobubbles generated by acoustic cavitation tend to shrink and intensify interfacial thermal fluctuations; this significantly reduces surface tension to neutralize enhanced Laplace pressure, and secures their stabilization at a finite size. A stability criterion emerges: thermal fluctuation intensity scales superlinearly with curvature: sqrt[⟨h^{2}⟩]∝(1/R)^{n}, n>1. The model prolongs the time frame for nanobubble contraction to 2 orders of magnitude beyond classical theory estimates, and captures the equilibrium radius (90-215 nm) within the experimental range.

Role of Mutual Diffusion in the Dissolution Behavior of One Primary Bulk Gas Nanobubble in Liquid: A Molecular Dynamics Study.

Dissolution of one primary bulk gas nanobubble in an undersaturated liquid constitutes one of the underlying issues of the exceptional stability of bulk gas nanobubble population. In this paper, the mutual diffusion coefficient at the gas-liquid interface of one primary bulk gas nanobubble is investigated via all-atom molecular dynamics simulation, and the applicability of the Epstein-Plesset theory is verified. The mutual diffusion coefficient, different from the self-diffusion coefficient in bulk gas or bulk liquid, is essentially determined by the chemical potential due to its driving role in the mass transfer across the interface. We could ascribe the low-rate dissolution of one primary bulk gas nanobubble in an undersaturated liquid to the slight attenuation of the mutual diffusion coefficient at the interface. The results show that the dissolution process of one primary bulk gas nanobubble in an undersaturated liquid fundamentally obeys the Epstein-Plesset theory and that the macroscopic dissolution rate is intrinsically determined by the gas mutual diffusion coefficient at the interface rather than the self-diffusion coefficient in the bulk phase. The mass transfer viewpoint from the present study might actively promote subsequent studies on the super-stability of bulk gas nanobubble population in liquid.

[Surgical Safety of Elderly Hospitalized Patients Stratified by Age in General Surgery].

Objective To compare the surgical safety of elderly hospitalized patients in different age groups undergoing general surgery,and provide references for preoperative evaluation and treatment decision-making.Methods The inpatients ≥ 60 years old in the department of general surgery were selected from a national multi-center survey conducted from January to June in 2015 and from January to June in 2016.The patient characteristics and postoperative outcomes were described,and the risk factors for adverse postoperative outcomes of patients in different age groups were explored.Results The elderly patients (≥75 years old) accounted for 17.33%.The non-elderly patient (< 75 years old) group and the elderly patient (≥75 years old) group had significant differences in the proportions of patients with three or more chronical diseases (13.18% vs.5.36%,P<0.001),emergency surgery (16.64% vs.7.62%,P<0.001),American Society of Anesthesiologists score≥3 (48.68% vs.27.28%,P<0.001),and postoperative return to the intensive care unit(33.64% vs.12.00%,P<0.001).The occurrence of postoperative infectious complications showed no significant difference between the two age groups (7.29% vs.6.40%,P=0.410),while severe complications differed between the two groups (6.51% vs.2.60%,P<0.001).Besides,emergency surgery was a common independent risk factor for the two age groups.Conclusions Advanced age is not a contraindication to surgery of elderly patients.With consideration to patient's physical conditions and available surgical resources,elderly patients can still benefit from surgery.

[Patterns of Perioperative Blood Transfusion in Patients with Blood Loss during Major Cardiac Surgery].

Objective To investigate the patterns of perioperative blood transfusion in patients with blood loss during major cardiac surgery,so as to provide data reference for rational and standardized blood use.Methods The adult patients(aged 18 years or above)who underwent vascular surgery,coronary artery bypass grafting surgery,heart valve surgery or surgery for congenital heart disease in a national multicenter(four large hospitals)survey in China,2015-2016 were included in this study.We described their baseline characteristics,postoperative outcomes,and in particular,bleeding and patterns of perioperative blood transfusion(autologous and allogeneic,the latter including red blood cells,plasma,and platelet,or a combination of these components).Results Autologous blood transfusion in operation accounted for the highest proportion(58.84%)in patients undergoing heart valve surgery.The patients undergoing vascular surgery had the largest autologous blood transfusion volume(722 ml)and the highest intraoperative transfusion proportion of allogeneic blood(53.28%),especially that of platelet(39.34%).Compared with the transfusion of red blood cells,the transfusion of other blood components showed concentrated time distribution,and the proportion of plasma transfusion was the highest one day post operation.With the increase in bleeding volume,combined transfusion presented increased proportion and became the dominant transfusion pattern.Conclusions The blood transfusion patterns varied significantly depending on different types of cardiac surgery,different perioperative stages,and different bleeding volumes.It is necessary to formulate the targeted transfusion practice scheme on the basis of understanding the current situation,so as to make better use of blood resources and improve the safety of transfusion.

Aminolactonization of Unactivated Alkenes Catalyzed by Aryl Iodine.

A one-step protocol of the aryl iodine-catalyzed aminolactonization of unactivated alkenes under oxidation conditions was first reported to efficiently construct diverse amino lactones in a short time using HNTs2 as the compatible nitrogen source. In addition, we investigated the influence of the reaction rate based on the structure of the iodoarene precatalyst, which revealed the selective adjustment effect on aminolactonization and oxylactonization. Finally, preliminary experiments verified the feasibility of asymmetric aminolactonization catalyzed by a chiral iodoarene precatalyst.

Iodoarene-Catalyzed Oxyamination of Unactivated Alkenes to Synthesize 5-Imino-2-Tetrahydrofuranyl Methanamine Derivatives.

Reported here is the room-temperature metal-free iodoarene-catalyzed oxyamination of unactivated alkenes. In this process, the alkenes are difunctionalized by the oxygen atom of the amide group and the nitrogen in an exogenous HNTs2 molecule. This mild and open-air reaction provided an efficient synthesis to N-bistosyl-substituted 5-imino-2-tetrahydrofuranyl methanamine derivatives, which are important motifs in drug development and biological studies. Mechanistic study based on experiments and density functional theory calculations showed that this transformation proceeds via activation of the substrate alkene by an in situ generated cationic iodonium(III) intermediate, which is subsequently attacked by an oxygen atom (instead of nitrogen) of amides to form a five-membered ring intermediate. Finally, this intermediate undergoes an SN2 reaction by NTs2 as the nucleophile to give the oxygen and nitrogen difunctionalized 5-imino-2-tetrahydrofuranyl methanamine product. An asymmetric variant of the present alkene oxyamination using chiral iodoarenes as catalysts also gave promising results for some of the substrates.

[Toxoplasma gondii Infection in HIV-infected Individuals in Henan Province].

Genomic DNA was extracted from 1 038 peripheral blood samples from HIV-infected individuals in Henan Province. One-step single-tube nested PCR was performed to amplify the 529 bp repeating sequences of Toxoplasma gondii. Of the 1 038 samples （762 from males and 276 from females）, 66 showed positive PCR results, with a positive rate of 6.4%. The PCR positive rate in males and females was 6.3% （48/762） and 6.5% （18/276） respectively. The PCR positive rate in the married HIV individuals was 4.9%（25/508）, and that in unmarried, divorced and widowed HIV individuals was 7.7% （41/530）（χ2 = 3.451, P> 0.05）. The PCR positive rate in HIV individuals with a high-school educational level or above was 6.9%（34/489）, and that in those below the high-school level was 5.8% （32/549）（χ2 = 0.545, P> 0.05）. The highest infection rate was in the age group of 20-40 years（7.6%, 31/410）. In addition, the Toxoplasma infection rate in those with and without a history of venereal diseases, and those with an unknown history was 8.0%（9/113）, 6.5%（50/773） and 4.6%（7/152） respectively （χ2 = 0.355, P> 0.05）.

Effective Underwater Drag Reduction: A Butterfly Wing Scale-Inspired Superhydrophobic Surface.

The microstructured superhydrophobic surface serves as an alternative strategy to decrease resistance of underwater vehicles, but the sustainment of an entrapped air layer and the stability of the corresponding gas-liquid interface within textures in flow shear or high pressure are still a great challenge. Inspired by the scales of Parantica melaneus wings, we propose a biomimetic surface with a hierarchical structure featuring longitudinal ridges and regular cavities that firmly pin the gas-liquid interface. The drag reduction rate of the Butterfly Wing Scale-Like Surface (BWSLS) demonstrates a noticeable rise over the single-scale textured mainstream biomimetic surfaces at moderate Reynolds numbers. The superior drag reduction mechanism is revealed as the synergistic effect of a thicker gas film and a more pronounced secondary vortex within the hierarchical textures. The former reduces the velocity gradient near the surface, while the latter decreases the vorticity and energy dissipation. In a high hydrostatic pressure environment, the proposed surface also demonstrates significant stability of the gas-liquid interface, with a gas coverage rate of over 67% during the cyclic loading, surpassing single-structured surfaces. Our study suggests promising surface designs for optimal drag reduction by mimicking and leveraging diverse surfaces of organisms adapted to oceanic climates.

Calix[2]azolium[2]benzimidazolone hosts for selective binding of neutral substrates in water.

The separation and purification of chemical raw materials, particularly neutral compounds with similar physical and chemical properties, represents an ongoing challenge. In this study, we introduce a class of water-soluble macrocycle compound, calix[2]azolium[2]benzimidazolone (H), comprising two azolium and two benzimidazolone subunits. The heterocycle subunits form a hydrophobic binding pocket that enables H1 to encapsulate a series of neutral guests in water with 1:1 or 2:1 stoichiometry, including aldehydes, ketones, and nitrile compounds. The host-guest complexation in the solid state was further confirmed through X-ray crystallography. Remarkably, H1 was shown to be a nonporous adaptive crystal material to separate valeraldehyde from the mixture of valeraldehyde/2-methylbutanal/pentanol with high selectivity and recyclability in the solid states. This work not only demonstrates that azolium-based macrocycles are promising candidates for the encapsulation of organic molecules but also shows the potential application in separation science.

Auraptene-ameliorating depressive-like behaviors induced by lipopolysaccharide combined with chronic unpredictable mild stress in mice mitigate hippocampal neuroinflammation mediated by microglia.

An inflammatory response is one of the pathogeneses of depression. The anti-inflammatory and neuroprotective effects of auraptene have previously been confirmed. We established an inflammatory depression model by lipopolysaccharide (LPS) injection combined with unpredictable chronic mild stress (uCMS), aiming to explore the effects of auraptene on depressive-like behaviors in adult mice. Mice were divided into a control group, vehicle group, fluoxetine group, celecoxib group, and auraptene group. Then, behavioral tests were conducted to evaluate the effectiveness of auraptene in ameliorating depressive-like behavior. Cyclooxygenase-2 (COX-2), C-reactive protein (CRP), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), and interleukin-1ß (IL-1ß) were examined by ELISA. Interleukin-10 (IL-10), interleukin-4 (IL-4), and transforming growth factor-ß (TGF-ß) were examined by protein chip technology. The morphology of microglia was observed by the immunohistochemical method. The data showed that, compared with the control group, the vehicle group mice exhibited a depressive-like behavioral phenotype, accompanied by an imbalance in inflammatory cytokines and the activation of microglia in the hippocampus. The depressive behaviors of the auraptene group's mice were significantly alleviated, along with the decrease in pro-inflammatory factors and increase in anti-inflammatory factors, while the activation of microglia was inhibited in the hippocampus. Subsequently, we investigated the role of auraptene in vitro-cultured BV-2 cells treated with LPS. The analysis showed that auraptene downregulated the expression of IL-6, TNF-α, and NO, and diminished the ratio of CD86/CD206. The results showed that auraptene reduced the excessive phagocytosis and ROS production of LPS-induced BV2 cells. In conclusion, auraptene relieved depressive-like behaviors in mice probably via modulating hippocampal neuroinflammation mediated by microglia.

Design, synthesis fusidic acid derivatives alleviate acute lung injury via inhibiting MAPK/NF-κB/NLRP3 pathway.

Acute lung injury (ALI) refers to a series of lung lesions resulting from multiple lung injuries, even leading to morbidity and death, abundant previous reports have showed that anti-inflammatory as a key to treatment of ALI. Fusidic acid (FA) as an antibiotic has significant anti-bacterial activity and anti-inflammatory effects. In this study, we designed and synthesized 34 FA derivatives to identify new anti-inflammatory drugs. The anti-inflammatory activities of the derivatives were screened using lipopolysaccharide (LPS)-induced RAW264.7 cells to evaluate the anti-inflammatory activity of the compounds, we measured nitric oxide (NO) and interleukin-6 (IL-6). Most of compounds showed inhibitory effects on inflammatory NO and IL-6 in LPS-induced RAW264.7 cells. Based on the screening results, compound a1 showed the strongest anti-inflammatory activity. Compared with FA, the inhibition rate NO and IL-6 of compound a1 increased 3.08 and 2.09 times at 10 µM, respectively. We further measured a1 inhibited inflammatory factor NO (IC50 = 3.26 ± 0.42 µM), IL-6 (IC50 = 1.85 ± 0.21 µM) and TNF-α (IC50 = 3.88 ± 0.55 µM). We also demonstrated that a1 markedly inhibits the expression of certain immune-related cytotoxic factors, including cyclooxygenase-2 (COX-2) and inducible nitric-oxide synthase (iNOS). In vivo results indicate that a1 can reduce lung inflammation and NO, IL-6, TNF-α, COX-2 and iNOS in LPS-induced ALI mice. On the one hand, we demonstrated a1 inhibits the mitogen-activated protein kinase (MAPK) signaling pathway by down-regulating the phosphorylation of p38 MAPK, c-Jun N-terminal kinase (c-JNK) and extracellular signal-regulated kinase (ERK). Moreover, a1 also suppressing the phosphorylation of inhibitory NF-κB inhibitor α (IκBα) inhibits the activation of the nuclear factor-κB (NF-κB) signaling pathway. On the other hand, we demonstrated a1 also role in anti-inflammatory by inhibits nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3) inflammasome and further inhibits Caspase-1 and inflammatory factor interleukin-1ß (IL-1ß). In conclusion, our study demonstrates that a1 has an anti-inflammatory effect and alleviates ALI by regulating inflammatory mediators and suppressing the MAPK, NF-κB and NLRP3 inflammasome signaling pathways.

Genomic insights into local adaptation in the Asiatic toad Bufo gargarizans, and its genomic offset to climate warming.

Genomic signatures of local adaptation have been identified in many species but remain sparsely studied in amphibians. Here, we explored genome-wide divergence within the Asiatic toad, Bufo gargarizans, to study local adaptation and genomic offset (i.e., the mismatch between current and future genotype-environment relationships) under climate warming scenarios. We obtained high-quality SNP data for 94 Asiatic toads from 21 populations in China to study spatial patterns of genomic variation, local adaptation, and genomic offset to warming in this wide-ranging species. Population structure and genetic diversity analysis based on high-quality SNPs revealed three clusters of B. gargarizans in the western, central-eastern, and northeastern portions of the species' range in China. Populations generally dispersed along two migration routes, one from the west to the central-east and one from the central-east to the northeast. Both genetic diversity and pairwise F ST were climatically correlated, and pairwise F ST was also correlated with geographic distance. Spatial genomic patterns in B. gargarizans were determined by the local environment and geographic distance. Global warming will increase the extirpation risk of B. gargarizans.

Nanoarray-Embedded Hierarchical Surfaces for Highly Durable Dropwise Condensation.

Durable dropwise condensation of saturated vapor is of significance for heat transfer and energy saving in extensive industrial applications. While numerous superhydrophobic surfaces can promote steam condensation, maintaining discrete microdroplets on surfaces without the formation of a flooded filmwise condensation at high subcooling remains challenging. Here, we report the development of carbon nanotube array-embedded hierarchical composite surfaces that enable ultra-durable dropwise condensation under a wide range of subcooling (ΔT sub = 8 K-38 K), which outperforms existing nanowire surfaces. This performance stems from the combined strategies of the hydrophobic nanostructures that allow efficient surface renewal and the patterned hydrophilic micro frames that protect the nanostructures and also accelerate droplet nucleation. The synergistic effects of the composite design ensure sustained Cassie wetting mode and capillarity-governed droplet mobility (Bond number < 0.055) as well as the large specific volume of condensed droplets, which contributes to the enhanced condensation heat transfer. Our design provides a feasible alternative for efficiently transferring heat in a vapor environment with relatively high temperatures through the tunable multiscale morphology.

Gut microbiota differs between two cold-climate lizards distributed in thermally different regions.

BACKGROUND: The metabolic cold-climate adaption hypothesis predicts that animals from cold environments have relatively high metabolic rates compared with their warm-climate counterparts. However, studies testing this hypothesis are sparse. Here, we compared gut microbes between two cold-climate lizard species of the genus Phrynocephalus to see if gut microbiota could help lizards adapt to cold environments by promoting metabolism. We conducted a 2 species (P. erythrurus and P. przewalskii) × 2 temperatures (24 and 30 °C) factorial design experiment, whereby we kept lizards of two Phrynocephalus species at 24 and 30 °C for 25 d and then collected their fecal samples to analyze and compare the microbiota based on 16S rRNA gene sequencing technology. RESULTS: The gut microbiota was mainly composed of bacteria of the phyla Proteobacteria, Firmicutes, Bacteroidetes, and Verrucomicrobia in both species (Proteobacteria > Firmicutes > Verrucomicrobiota in P. erythrurus, and Bacteroidetes > Proteobacteria > Firmicutes in P. przewalskii). Further analysis revealed that the gut microbiota promoted thermal adaptation in both lizard species, but with differences in the relative abundance of the contributory bacteria between the two species. An analysis based on the Kyoto Encyclopedia of Genes and Genomes revealed that the gut microbiota played important roles in metabolism, genetic information processing, cellular processes, and environmental information processing in both species. Furthermore, genes related to metabolism were more abundant in P. erythrurus at 24 °C than in other species ⋅ temperature combinations. CONCLUSION: Our study provides evidence that gut microbiota promotes thermal adaptation in both species but more evidently in P. erythrurus using colder habitats than P. przewalskii all year round, thus confirming the role of gut microbiota in cold-climate adaptation in lizards.

Atomistic Insights into the Tunable Transition from Cavitation to Crazing in Diamond Nanothread-Reinforced Polymer Composites.

Cavitation and crazing in thermosetting polymers can be sophisticatedly designed for valuable applications in optics, electronics, and biotechnology. It is a great challenge for numerical study to describe the formations of cavity and fibrils in polymer composite due to the complicated interfacial interaction. To explore this challenging task, we exploit a two-phase coarse-grained framework which serves as an efficient atomistic level-consistent approach to expose and predict the transition between cavitation and crazing in a polymeric system. The coarse-grained framework is utilized to transmit the information between single phase and interface in polymer composite, and the learning tasks of force field are fulfilled through parameterization of mechanical performances and structural characterizations. We elaborate on the intrinsic characteristics of the cavitation-crazing transition in diamond nanothread- (DNT-) reinforced polymethyl methacrylate composites, in which DNT plays a specific role of nanomodulator to tune the cavity volume ratio. The transition from cavitation to crazing can be induced through a novel dissipative mechanism of opening an interlocked network, in which case the DNT is stretched to the aligned fibrils and links crazing tightly by interfacial adhesion. The designed computational framework can broaden the scope of theoretical tools for providing better insights into the microstructure design of polymer composites.

Transcriptomic analyses of humans and mice provide insights into depression.

Accumulating studies have been conducted to identify risk genes and relevant biological mechanisms underlying major depressive disorder (MDD). In particular, transcriptomic analyses in brain regions engaged in cognitive and emotional processes, e.g., the dorsolateral prefrontal cortex (DLPFC), have provided essential insights. Based on three independent DLPFC RNA-seq datasets of 79 MDD patients and 75 healthy controls, we performed differential expression analyses using two alternative approaches for cross-validation. We also conducted transcriptomic analyses in mice undergoing chronic variable stress (CVS) and chronic social defeat stress (CSDS). We identified 12 differentially expressed genes (DEGs) through both analytical methods in MDD patients, the majority of which were also dysregulated in stressed mice. Notably, the mRNA level of the immediate early gene FOS ( Fos proto-oncogene) was significantly decreased in both MDD patients and CVS-exposed mice, and CSDS-susceptible mice exhibited a greater reduction in Fos expression compared to resilient mice. These findings suggest the potential key roles of this gene in the pathogenesis of MDD related to stress exposure. Altered transcriptomes in the DLPFC of MDD patients might be, at least partially, the result of stress exposure, supporting that stress is a primary risk factor for MDD.

In vitro culture of mammalian inner ear hair cells.

Auditory function in vertebrates depends on the transduction of sound vibrations into electrical signals by inner ear hair cells. In general, hearing loss resulting from hair cell damage is irreversible because the human ear has been considered to be incapable of regenerating or repairing these sensory elements following severe injury. Therefore, regeneration and protection of inner ear hair cells have become an exciting, rapidly evolving field of research during the last decade. However, mammalian auditory hair cells are few in number, experimentally inaccessible, and barely proliferate postnatally in vitro. Various in vitro primary culture systems of inner ear hair cells have been established by different groups, although many challenges remain unresolved. Here, we briefly explain the structure of the inner ear, summarize the published methods of in vitro hair cell cultures, and propose a feasible protocol for culturing these cells, which gave satisfactory results in our study. A better understanding of in vitro hair cell cultures will substantially facilitate research involving auditory functions, drug development, and the isolation of critical molecules involved in hair cell biology.