Perfluorooctanoic acid effect and microbial mechanism to methane production in anaerobic digestion.

Perfluorooctanoic acid (PFOA) as emerging pollutants was largely produced and stable in nature environment. Its fate and effect to the wasted sludge digestion process and corresponding microbial mechanism was rarely reported. This study investigated the different dose of PFOA to the wasted sludge digestion process, where the methane yield and microbial mechanism was illustrated. The PFOA added before digestion were 0-10000 µg/L, no significant variation in daily and accumulated methane production between each group. The 9th day methane yield was significantly higher than other days (p < 0.05). The soluble protein was significantly decreased after 76 days digestion (p < 0.001). The total PFOA in sludge (R2 = 0.8817) and liquid (R2 = 0.9083) phase after digestion was exponentially correlated with PFOA dosed. The PFOA in liquid phase was occupied 54.10 ± 18.38% of the total PFOA in all reactors. The dewatering rate was keep decreasing with the increase of PFOA added (R2 = 0.7748, p < 0.001). The mcrA abundance was significantly correlated with the pH value and organic matter concentration in the reactors. Chloroflexi was the predominant phyla, Aminicenantales, Bellilinea and Candidatus_Cloacimonas were predominant genera in all reactors. Candidatus_Methanofastidiosum and Methanolinea were predominant archaea in all reactors. The function prediction by FAPROTAX and Tax4fun implied that various PFOA dosage resulted in significant function variation. The fermentation and anaerobic chemoheterotrophy function were improved with the PFOA dose. Co-occurrence network implied the potent cooperation among the organic matter degradation and methanogenic microbe in the digestion system. PFOA has little impact to the methane generation while affect the microbe function significantly, its remaining in the digested sludge should be concerned to reduce its potential environmental risks.

Evaporative self-assembly in colloidal droplets: Emergence of ordered structures from complex fluids.

Colloidal droplet evaporation is an intriguing and intricate phenomenon that has captured the interest of scientists across diverse disciplines, including physical chemistry, fluid dynamics, and soft matter science, over the past two decades. Despite being a non-equilibrium system with inherent challenges posed by coffee ring formation and Marangoni effects, which hinder the precise control of deposition patterns, evaporative self-assembly presents a convenient and cost-effective approach for generating arrays of well-ordered structures and functional patterns with wide-ranging applications in inkjet printing, photonic crystals, and biochemical assays. In the realm of printed electronics and photonics, effectively mitigating coffee rings while achieving uniformity and orderliness has emerged as a critical factor in realising the next generation of large-area, low-cost, flexible devices that are exceptionally sensitive and high-performance. This review highlights the evaporative self-assembly process in colloidal droplets with a focus on the intricate mechanical environment, self-assembly at diverse interfaces, and potential applications of these assembling ordered structures.

Increasing fish production in recirculating aquaculture system by integrating a biofloc-worm reactor for protein recovery.

Aquaculture, producing half of global fish production, offers a high-quality protein source for humans. Improving nitrogen use efficiency (NUE) through microbial protein recovery is crucial for increasing fish production and reducing environmental footprint. However, the poor palatability and high moisture content of microbial protein make its utilization challenging. Here, a biofloc-worm reactor was integrated into a recirculating aquaculture system (BW_RAS) for the first time to convert microbial protein into Tubificidae (Oligochaeta) biomass, which was used as direct feed for culturing fish. Batch experiments indicated that an aeration rate of 0.132 m3 L -1 h -1 and a worm density of 0.3 g cm-2 on the carrier were optimal for microbial biomass growth and worm predation, respectively. Compared to the biofloc reactor-based recirculating aquaculture system (B_RAS), the BW_RAS improved water quality, NUE, and fish production by 17.1 % during a 120-day aquaculture period. The abundance of heterotrophic aerobic denitrifier Deinococcus in BW_RAS was one order of magnitude higher than in B_RAS, while heterotrophic bacteria Mycobacterium was more abundant in B_RAS. Denitrifiers cooperated with organic matter degraders and nitrogen assimilation bacteria for protein recovery and gaseous nitrogen loss while competing with predatory bacteria. Function prediction and qPCR indicated greater aerobic respiration, nitrate assimilation, nitrification (AOB-amoA), and denitrification (napA, nirK, nirS, nosZI), but lower fermentation in BWR compared to BR. This study demonstrated that BW_RAS increased microbial protein production and aerobic nitrogen cycling through ongoing worm predation, further enhancing fish production to a commercially viable level.

Surgical advantage of modified labial salivary gland biopsy using chalazion forceps: a prospective randomized controlled study.

Labial salivary gland biopsy (LSGB) is one of the specific diagnostic criteria for primary Sjögren's syndrome (pSS). In traditional LSGB, there is no lower lip fixation device, the field of view is unclear due to intraoperative bleeding, and the incision is large, which is unfavourable for healing. The use of auxiliary devices to improve the shortcomings of traditional LSGB technique would be meaningful. Therefore, this case-control study aimed to assess the value of modified LSGB using chalazion forceps as compared with traditional LSGB. After obtaining written informed consent from all participating parents and patients, we randomly assigned 217 eligible participants to undergo LSGB using chalazion forceps (n = 125) or traditional LSGB (n = 92). The outcome variables were surgical time, incision length, intraoperative bleeding, pain score at 24 h after surgery, incision healing status at 7 days after surgery, gland collection, and pathological results. The final diagnostic results of the two surgical methods were compared, and the match rates between the pathological results and the final clinical diagnoses were compared between the two groups. The data were analysed using parametric and nonparametric tests. Compared with the traditional group, the modified group had a smaller incision, shorter operative time, less blood loss, lower 24 h pain score, and better Grade A incision healing at 7 days after surgery (p < 0.01). There was no statistically significant difference between the patients in the two surgical-method groups in terms of the positive biopsy results and the final diagnosis based on expert opinions (p > 0.05). By multivariable regression analysis, only a focus score (FS) of ≥ 1 (p < 0.01), dry eye disease (p < 0.05) and anti-nuclear antibodies (ANA) titre ≥ 1:320 (p < 0.05) were correlated with the diagnosis of pSS. The positive biopsy results of patients in the different surgical-method groups had a biopsy accuracy of > 80.0% for the diagnosis of pSS. The positive biopsy results in the different surgical-method groups were consistent with the expert opinions and the 2016 ACR-EULAR primary SS classification criteria. The modified LSGB using an auxiliary chalazion forceps offers a good safety with a small incision, shorter operative time, less bleeding, reduced pain and a low incidence of postoperative complications.The match rate of LSGB pathological results of the proposed surgical procedure with the final diagnosis of pSS is high.

Liraglutide Promotes Diabetic Wound Healing via Myo1c/Dock5.

Non-healing diabetic wounds and ulcer complications, with persistent cell dysfunction and obstructed cellular processes, are leading causes of disability and death in patients with diabetes. Currently, there is a lack of guideline-recommended hypoglycemic drugs in clinical practice, likely due to limited research and unclear mechanisms. In this study, it is demonstrated that liraglutide significantly accelerates wound closure in diabetic mouse models (db/db mice and streptozotocin-induced mice) by improving re-epithelialization, collagen deposition, and extracellular matrix remodeling, and enhancing the proliferation, migration, and adhesion functions of keratinocytes. However, these effects of improved healing by liraglutide are abrogated in dedicator of cytokinesis 5 (Dock5) keratinocyte-specific knockout mice. Mechanistically, liraglutide induces cellular function through stabilization of unconventional myosin 1c (Myo1c). Liraglutide directly binds to Myo1c at arginine 93, enhancing the Myo1c/Dock5 interaction by targeting Dock5 promoter and thus promoting the proliferation, migration, and adhesion of keratinocytes. Therefore, this study provides insights into liraglutide biology and suggests it may be an effective treatment for diabetic patients with wound-healing pathologies.

CD9 Counteracts Liver Steatosis and Mediates GCGR Agonist Hepatic Effects.

Glucagon receptor (GCGR) agonism offers potentially greater effects on the mitigation of hepatic steatosis. However, its underlying mechanism is not fully understood. Here, it screened tetraspanin CD9 might medicate hepatic effects of GCGR agonist. CD9 is decreased in the fatty livers of patients and upregulated upon GCGR activation. Deficiency of CD9 in the liver exacerbated diet-induced hepatic steatosis via complement factor D (CFD) regulated fatty acid metabolism. Specifically, CD9 modulated hepatic fatty acid synthesis and oxidation genes through regulating CFD expression via the ubiquitination-proteasomal degradation of FLI1. In addition, CD9 influenced body weight by modulating lipogenesis and thermogenesis of adipose tissue through CFD. Moreover, CD9 reinforcement in the liver alleviated hepatic steatosis, and blockage of CD9 abolished the remission of hepatic steatosis induced by cotadutide treatment. Thus, CD9 medicates the hepatic beneficial effects of GCGR signaling, and may server as a promising therapeutic target for hepatic steatosis.

Comparison and optimization of different CRISPR/Cas9 donor-adapting systems for gene editing.

Gene knock-in in mammalian cells usually uses homology-directed repair (HDR) mechanism to integrate exogenous DNA template into the target genome site. However, HDR efficiency is often low, and the co-localization of exogenous DNA template and target genome site is one of the key limiting factors. To improve the efficiency of HDR mediated by CRISPR/Cas9 system, our team and previous studies fused different adaptor proteins with SpCas9 protein and expressed them. By using their characteristics of binding to specific DNA sequences, many different CRISPR/SpCas9 donor adapter gene editing systems were constructed. In this study, we used them to knock-in eGFP gene at the 3'-end of the terminal exon of GAPDH and ACTB genes in HEK293T cells to facilitate a comparison and optimization of these systems. We utilized an optimized donor DNA template design method, validated the knock-in accuracy via PCR and Sanger sequencing, and assessed the efficiency using flow cytometry. The results showed that the fusion of yGal4BD, hGal4BD, hLacI, hTHAP11 as well as N57 and other adaptor proteins with the C-terminus of SpCas9 protein had no significant effect on its activity. At the GAPDH site, the donor adapter systems of SpCas9 fused with yGal4BD, hGal4BD, hLacI and hTHAP11 significantly improved the knock-in efficiency. At the ACTB site, SpCas9 fused with yGal4BD and hGal4BD significantly improved the knock-in efficiency. Furthermore, increasing the number of BS in the donor DNA template was beneficial to enhance the knock-in efficiency mediated by SpCas9-hTHAP11 system. In conclusion, this study compares and optimizes multiple CRISPR/Cas9 donor adapter gene editing systems, providing valuable insights for future gene editing applications.

Plasma Asprosin Concentrations are Associated with Progression of Diabetic Kidney Disease.

Purpose: To explore the expression of asprosin in subjects with pre-DKD and DKD and to analyze its relationship with kidney injury, inflammation, and glucose and lipid metabolism. Methods: Based on urine albumin:creatinine ratio (UACr), participants were divided into DM, pre-DKD, and DKD groups. Relevant human physiological and biochemical parameters were detected in the three groups. Results: We found relatively higher levels of asprosin in both pre-DKD and DKD groups than the DM group. Moreover, data from the Nephroseq database support increased gene expression of asprosin in kidney tissue from DKD patients. Further correlation analysis revealed that the plasma asprosin level was positively correlated with age, waist circumference, waist:hip ratio, systolic blood pressure, creatinine, UACr, triglycerides, HDL-c, fasting insulin, HOMA-IR, and the inflammatory marker G3P and negatively associated with eGFR. Multiple logistical regression analysis showed that asprosin concentration was significantly associated with pre-DKD and DKD after adjusting for sex, age, BMI, WHR, and HOMA-IR, while this correlation was lost after controlling for G3P. Conclusion: Plasma asprosin is associated with kidney injury in diabetic conditions, and this association might be connected through inflammatory response. Further studies are needed to assess the role and mechanism of asprosin in DKD.

Mitochondrial glycerol 3-phosphate dehydrogenase deficiency exacerbates lipotoxic cardiomyopathy.

Metabolic diseases such as obesity and diabetes induce lipotoxic cardiomyopathy, which is characterized by myocardial lipid accumulation, dysfunction, hypertrophy, fibrosis and mitochondrial dysfunction. Here, we identify that mitochondrial glycerol 3-phosphate dehydrogenase (mGPDH) is a pivotal regulator of cardiac fatty acid metabolism and function in the setting of lipotoxic cardiomyopathy. Cardiomyocyte-specific deletion of mGPDH promotes high-fat diet induced cardiac dysfunction, pathological hypertrophy, myocardial fibrosis, and lipid accumulation. Mechanically, mGPDH deficiency inhibits the expression of desuccinylase SIRT5, and in turn, the hypersuccinylates majority of enzymes in the fatty acid oxidation (FAO) cycle and promotes the degradation of these enzymes. Moreover, manipulating SIRT5 abolishes the effects of mGPDH ablation or overexpression on cardiac function. Finally, restoration of mGPDH improves lipid accumulation and cardiomyopathy in both diet-induced and genetic obese mouse models. Thus, our study indicates that targeting mGPDH could be a promising strategy for lipotoxic cardiomyopathy in the context of obesity and diabetes.

Greenhouse gases emissions from aquaculture ponds: Different emission patterns and key microbial processes affected by increased nitrogen loading.

Global aquaculture production is expected to rise to meet the growing demand for food worldwide, potentially leading to increased anthropogenic greenhouse gases (GHG) emissions. As the demand for fish protein increases, so will stocking density, feeding amounts, and nitrogen loading in aquaculture ponds. However, the impact of GHG emissions and the underlying microbial processes remain poorly understood. This study investigated the GHG emission characteristics, key microbial processes, and environmental drivers underlying GHG emissions in low and high nitrogen loading aquaculture ponds (LNP and HNP). The N2O flux in HNP (43.1 ± 11.3 µmol m-2 d-1) was significantly higher than in LNP (-11.3 ± 25.1 µmol m-2 d-1), while the dissolved N2O concentration in HNP (52.8 ± 7.1 nmol L-1) was 150 % higher than in LNP (p < 0.01). However, the methane (CH4) and carbon dioxide (CO2) fluxes and concentrations showed no significant differences (p > 0.05). N2O replaced CH4 as the main source of Global Warming Potential in HNP. Pond sediments acted as a sink for N2O but a source for CH4 and CO2. The △N2O/(△N2O + â–³N2) in HNP (0.015 ± 0.007 %) was 7.7-fold higher than in LNP (0.002 ± 0.001 %) (p < 0.05). The chemical oxygen demand to NO2-N ratio was the most important environmental factor explaining the variability of N2O fluxes. Ammonia-oxidizing bacteria driven nitrification in water was the predominant N2O source, while comammox-driven nitrification and nosZII-driven N2O reduction in water were key processes for reducing N2O emission in LNP but decreased in HNP. The strong CH4 oxidization by Methylocystis and CO2 assimilation by algae resulted in low CH4 emissions and CO2 sink in the aquaculture pond. The Mantel test indicated that HNP increased N2O fluxes mainly through altering functional genes composition in water and sediment. Our findings suggest that there is a significant underestimation of N2O emissions without considering the significantly increased △N2O/(△N2O + â–³N2) caused by increased nitrogen loading.

Dock5 Deficiency Promotes Proteinuric Kidney Diseases via Modulating Podocyte Lipid Metabolism.

Podocytes are particularly sensitive to lipid accumulation, which has recently emerged as a crucial pathological process in the progression of proteinuric kidney diseases like diabetic kidney disease and focal segmental glomerulosclerosis. However, the underlying mechanism remains unclear. Here, podocytes predominantly expressed protein dedicator of cytokinesis 5 (Dock5) is screened to be critically related to podocyte lipid lipotoxicity. Its expression is reduced in both proteinuric kidney disease patients and mouse models. Podocyte-specific deficiency of Dock5 exacerbated podocyte injury and glomeruli pathology in proteinuric kidney disease, which is mainly through modulating fatty acid uptake by the liver X receptor α  (LXRα)/scavenger receptor class B (CD36) signaling pathway. Specifically, Dock5 deficiency enhanced CD36-mediated fatty acid uptake of podocytes via upregulating LXRα in an m6 A-dependent way. Moreover, the rescue of Dock5 expression ameliorated podocyte injury and proteinuric kidney disease. Thus, the findings suggest that Dock5 deficiency is a critical contributor to podocyte lipotoxicity and may serve as a promising therapeutic target in proteinuric kidney diseases.

High nitrous oxide (N2O) greenhouse gas reduction potential of Pseudomonas sp. YR02 under aerobic condition.

Aerobic environments exist widely in wastewater treatment plants (WWTP) and are unfavorable for greenhouse gas nitrous oxide (N2O) reduction. Here, a novel strain Pseudomonas sp. YR02, which can perform N2O reduction under aerobic conditions, was isolated. The successful amplification of four denitrifying genes proved its complete denitrifying ability. The inorganic nitrogen (IN) removal efficiencies (NRE) were >98.0% and intracellular nitrogen and gaseous nitrogen account for 52.6-58.4% and 41.6-47.4% of input nitrogen, respectively. The priority of IN utilization was TAN > NO3--N > NO2--N. The optimal conditions for IN and N2O removal were consistent, except for the C/N ratio, which is 15 and 5 for IN and N2O removal, respectively. The biokinetic constants analysis indicated strain YR02 had high potential to treat high ammonia and dissolved N2O wastewater. Strain YR02 bioaugmentation mitigated 98.7% of N2O emission and improved 32% NRE in WWTP, proving its application potential for N2O mitigation.

Time-Dependent Seismic Reliability of Coastal Bridge Piers Subjected to Nonuniform Corrosion.

Coastal bridge piers suffer random performance deterioration owing to the presence of complex nonuniform corrosion characteristics and material uncertainties. Some of these piers will also be threatened by random earthquakes during a long-term service period, and therefore, structural safety needs to be probabilistically assessed by the seismic reliability method. To deal with this problem, we present a method to calculate the time-dependent reliability of the coastal bridge pier, comprehensively considering the randomness of a seismic event, nonuniform corrosion, and material uncertainty. First, the time-dependent M-N interaction diagrams are established by using the Monte Carlo simulation method. On the basis of the interaction diagrams, the moment resistance reduction function and time-dependent moment resistance distribution are determined. Subsequently, the moment demand under the seismic load is determined using the Poisson model and the response acceleration spectrum. Then, the formulas to calculate the time-dependent reliability of a nonuniform corroded pier are derived on the basis of the theorem of total probability. The proposed method is illustrated with a case study of a coastal bridge pier. It was found that the increase in corrosion damage would obviously increase time-dependent reliability. Furthermore, the increase in submerged zone height delayed the year when the failure section shifts from the pier bottom to the bottom of the splash and tidal zone, and it reduces the failure probability of the coastal pier. The research results presented herein show that the nonuniform corrosion manifestations influence the failure mode-related time-dependent seismic reliability of the coastal bridge pier.

Serum Annexin A2 concentrations are increased in patients with diabetic cardiomyopathy and are linked to cardiac dysfunctions.

BACKGROUND: Diabetic cardiomyopathy (DbCM) is defined as the existence of abnormal myocardial structure and functions in the absence of other cardiac diseases, such as coronary artery disease, hypertension, and significant valvular disease, in individuals with diabetes. Although abundant epidemic evidence demonstrates that diabetes is independently associated with the risk of developing heart failure, DbCM is not normally diagnosed in clinical practices due to its exclusive diagnosis, and no diagnostic biomarker was applied in a clinical test. METHODS: To detect the concentrations of serum Annexin A2 in non-diabetic subjects, type 2 diabetic (T2DM) patients with or without DbCM, and analyzed its relationship to parameters of cardiac functions, glucose, lipid metabolism, and renal functions. 266 eligible participants were included and were divided into 3 groups including non-diabetic subjects (NGR), T2DM patients without DbCM (T2DM group), and the DbCM group. Echocardiography, coronary computed tomography angiography, electrocardiogram, blood pressure, thyroid function, and clinical and other biochemical parameters were measured in all participants. RESULTS: Serum Annexin A2 concentrations were higher in DbCM (P < 0.05) and T2DM (P < 0.05) groups compared with the NGR group, especially in DbCM patients. Correlation analysis showed that serum Annexin A2 levels were negatively associated with left ventricular (LV) ejection fraction (EF), LV fractional shortening (FS), the ratio of early (E-wave) and late (A-wave) LV diastolic filling velocities (E/A ratio), and estimated glomerular filtration rate (eGFR), and were positively correlated with age, blood urea nitrogen (BUN) and creatinine (Cr) (all P < 0.05). Multiple logistical regression analyses revealed that serum in both the second and the third tertiles of Annexin A2 concentration were significantly associated with DbCM. E/A ratio is the independent factor for Annexin A2 concentration when adjusted for LV FS%, BUN, and Cr. CONCLUSIONS: Circulating Annexin A2 concentrations might be induced in DbCM patients and were negatively associated with cardiac systolic and diastolic functions, which suggested it might be a predictor of early diagnosis in DbCM and might be a potential therapeutic target for DbCM.

The Effects of Bone Cement Volume in Percutaneous Vertebroplasty for Thoracolumbar Junction Vertebral Compression Fractures: A Clinical Comparative Study.

We compared the outcomes of patients treated with different volumes of polymethyl methacrylate bone cement during percutaneous vertebroplasty (PVP) for thoracolumbar vertebral compression fractures. We performed a comparative, retrospective study of 316 patients who underwent PVP for a single-level thoracolumbar vertebral compression fracture. Patients were divided into two groups: group A (≤5 mL; n = 146) and group B (>5 mL; n = 170). The visual analogue scale (VAS) for pain and the Roland-Morris Disability Questionnaire (RDQ) scores were compared between the two groups at 1 week and at 1, 6, 12, and 24 months after PVP. The incidence of cement leakage into the intervertebral discs was evaluated by a postoperative lateral radiograph assessment. Patients were evaluated for new fractures 1 and 2 years after PVP or when new fractures were suspected. Among the 316 patients enrolled, 245 completed the clinical research. No difference between groups A and B in terms of the VAS, RDQ, and rate of complications at all time points after surgery was observed. The presence of intervertebral disc leakage was a relative risk (RR) for subsequent total vertebral fracture (RR, 6.42; 95% confidence interval (CI), 2.72-14.19; P < 0.0001) and adjacent vertebral fracture (RR, 8.03; 95% CI, 2.74-23.54; P = 0.0001). A high volume of bone cement may increase the rate of subsequent total and adjacent vertebral fractures. However, the occurrence of intervertebral disc leakage is the principal risk factor for these negative outcomes of PVP.

NickelII-catalyzed asymmetric photoenolization/Mannich reaction of (2-alkylphenyl) ketones.

A diastereo- and enantioselective photoenolization/Mannich (PEM) reaction of ortho-alkyl aromatic ketones with benzosulfonimides was established by utilizing a chiral N,N'-dioxide/Ni(OTf)2 complex as the Lewis acid catalyst. It afforded a series of benzosulfonamides and the corresponding ring-closure products, and a reversal of diastereoselectivity was observed through epimerization of the benzosulfonamide products under continuous irradiation. On the basis of the control experiments, the role of the additive LiNTf2 in achieving high stereoselectivity was elucidated. This PEM reaction was proposed to undergo a direct nucleophilic addition mechanism rather than a hetero-Diels-Alder/ring-opening sequence. A possible transition state model with a photoenolization process was proposed to explain the origin of the high level of stereoinduction.

Imbibition-induced ultrafast assembly and printing of colloidal photonic crystals.

HYPOTHESIS: Self-assembly of colloidal particles enables the versatile fabrication of highly ordered structures and materials for optical, sensing, and other applications. Nevertheless, many traditional assembly processes are inefficient, because there exists an inevitable contradiction between time efficiency and crystalline quality. In this work, we introduce an ultrafast, robust, and scalable approach of imbibition-induced assembly. We assume that the instantaneous solvent imbibition induced by the nanoporous media could direct ultrafast self-assembly of colloidal particles into ordered structures. EXPERIMENTS: Self-assembly of colloidal particles from a droplet on a nanoporous substrate was firstly observed and investigated. A phase diagram of the thickness of the colloidal crystal as a function of the printing speed and the particle volume fraction was presented through systematic experiments. FINDINGS: The nanoporous substrate can induce strong capillary flow that will directthe rapid self-assemblyof particles intocolloidalcrystals. The imbibition-induced assembly was spatially and temporally combined with the meniscus-guided printing approach, and the printing speed can be improved by two orders of magnitude than the traditional evaporative assembly methods. We finally demonstrate an effective and ultrafast approach for assembling colloidal particles into photonic crystals with controllable sizes and shapes on the macroscale.

Dissolved Oxygen-Sensing Chip Integrating an Open Container Connected with a Position-Raised Channel for Estimation of Cellular Mitochondrial Activity.

The measurement of oxygen consumption of adherent cells is a profoundly important issue for estimating the bioenergetic health and metabolism activity of cells. The study describes the construction of a microfluidic chip consisting of an open container connected with a position-raised channel and dissolved oxygen (DO)-sensing gold ultramicroelectrodes for quantifying the oxygen consumption rate (OCR) of adherent cells. The microfluidic chip design can reduce the action of shear force on the adherent cells during medium replacement. The residual concentration of analytes in the open container was only 4.4% after solution replacement via the position-raised channel. The DO reduction current measured by ultramicroelectrodes averaged in the range of 40-60 s presented high reproducibility with a 1.1% relative standard deviation suitable for OCR calculation. After short-term (90 min) cultivation, the microfluidic chip can monitor the time-dependent change in the OCR of 3T3-L1 cells for several hours by repeatedly replacing the culture medium or with the stimulation of different mitochondrial inhibitors. The presented microfluidic cell-based chip has great promise for drug screening and chemosensitivity testing by measuring OCR to evaluate the mitochondrial function of adherent cells.

Wall-Confined Spreading Dynamics on the Surface of Surfactant Solution.

A liquid spreading over another is a universal physical process in the nature, which was investigated by the scaling law to reveal the underlying mechanical mechanism over the decades. However, scaling laws are restricted to piecewise physical stages, respectively. It is a challenge to present a full physical picture for a dynamic spreading process covering a wide-spectrum speed. We propose a general wall-confined spreading dynamics (WCSD) model originating from molecular kinetic theory (MKT). It creatively illustrates the order and domination between driving energy and energy dissipation (or transfer) using a phase diagram according to theory and experiments. This work reveals the deep mechanical mechanism of WCSD which provides an indirect guidance on the solution processing methods of two-dimensional molecular crystals (2DMCs) growth.

Ultrafast Self-Assembly of Colloidal Photonic Crystals during Low-Pressure-Assisted Evaporation of Droplets.

After evaporation of a sessile colloidal droplet, the coffee stain always emerges with disordered structures. This may be unfavorable for many applications, such as droplet-based printing. Therefore, to realize uniform and ordered patterns is becoming an urgent task. In this work, we realize ultrafast fabrication of uniform colloidal crystals by suppressing the coffee ring effect in flash evaporation of a droplet. The low-pressure environment can tremendously improve the evaporation rate, which will accelerate the colloidal particles to be captured by the gas-liquid interface and self-assemble into ordered structures instantaneously. With the control of the pressure and concentration, the uniform and ordered patterns can be realized in several seconds. The colloidal photonic crystals with diverse structural colors can be easily and rapidly obtained by adjusting the particle sizes. We think this work may have instructive significance in the rapid fabrication of high-quality and high-performance printed electronics.