Brain organoids derived from human pluripotent stem cells provide a highly valuable in vitro model to recapitulate human brain development and neurological diseases. However, the current systems for ...brain organoid culture require further improvement for the reliable production of high-quality organoids. Here, we demonstrate two engineering elements to improve human brain organoid culture, (1) a human brain extracellular matrix to provide brain-specific cues and (2) a microfluidic device with periodic flow to improve the survival and reduce the variability of organoids. A three-dimensional culture modified with brain extracellular matrix significantly enhanced neurogenesis in developing brain organoids from human induced pluripotent stem cells. Cortical layer development, volumetric augmentation, and electrophysiological function of human brain organoids were further improved in a reproducible manner by dynamic culture in microfluidic chamber devices. Our engineering concept of reconstituting brain-mimetic microenvironments facilitates the development of a reliable culture platform for brain organoids, enabling effective modeling and drug development for human brain diseases.
Matrigel, a mouse tumor extracellular matrix protein mixture, is an indispensable component of most organoid tissue culture. However, it has limited the utility of organoids for drug development and ...regenerative medicine due to its tumor-derived origin, batch-to-batch variation, high cost, and safety issues. Here, we demonstrate that gastrointestinal tissue-derived extracellular matrix hydrogels are suitable substitutes for Matrigel in gastrointestinal organoid culture. We found that the development and function of gastric or intestinal organoids grown in tissue extracellular matrix hydrogels are comparable or often superior to those in Matrigel. In addition, gastrointestinal extracellular matrix hydrogels enabled long-term subculture and transplantation of organoids by providing gastrointestinal tissue-mimetic microenvironments. Tissue-specific and age-related extracellular matrix profiles that affect organoid development were also elucidated through proteomic analysis. Together, our results suggest that extracellular matrix hydrogels derived from decellularized gastrointestinal tissues are effective alternatives to the current gold standard, Matrigel, and produce organoids suitable for gastrointestinal disease modeling, drug development, and tissue regeneration.
Triboelectric nanogenerators (TENGs) have recently shown promising potential as effective energy harvesters using human motion energy. However, the efficiency of polymer-based flexible TENG must be ...enhanced for various applications. In this work, we propose a flexible TENG with a fluorocarbon plasma-etched polydimethylsiloxane (PDMS)–carbon nanotube (CNT). The fluorocarbon plasma etching causes not only a chemical modification, but also a physical effect on the morphology of the PDMS–CNT surface to enhance the TENG output performance. The added CNT enhances the mechanical properties, such as durability, of a thin film. The etched PDMS structure and the revealed CNTs increase the charge density on the surface. We confirm the effect of different CNT concentrations doped in PDMS and various etching times. We propose a TENG with 4 wt% CNT, which has been subjected to fluorocarbon etching for 60 s. The TENG exhibits an output voltage of 77.8 V, which is 248.7% and 106.5% higher than that of pure PDMS and un-etched PDMS–CNT, respectively. The 20 mm × 30 mm TENG delivers an output power of 1.98 mW (3.29 W m −2 ) at a matching resistance of 3 MΩ. The TENG exhibits good stability and superior electrical performance, making it capable of driving both the instantaneous operation of 70 LEDs and the charging of a 0.33 μF capacitor to 6.6 V. Furthermore, this TENG can be used as a self-powered physical activity sensor that measures the amount of human activity through the amount of charge in the capacitor.
Swimming in low-Reynolds-number fluids requires the breaking of time-reversal symmetry and centrosymmetry. Microswimmers, often with asymmetric shapes, exhibit nonreciprocal motions or exploit ...nonequilibrium processes to propel. The role of the surrounding fluid has also attracted attention because viscoelastic, non-Newtonian, and anisotropic properties of fluids matter in propulsion efficiency and navigation. Here, we experimentally demonstrate that anisotropic fluids, nematic liquid crystals (NLC), can make a pulsating spherical bubble swim despite its centrosymmetric shape and time-symmetric motion. The NLC breaks the centrosymmetry by a deformed nematic director field with a topological defect accompanying the bubble. The nematodynamics renders the nonreciprocity in the pulsation-induced fluid flow. We also report speed enhancement by confinement and the propulsion of another symmetry-broken bubble dressed by a bent disclination. Our experiments and theory propose another possible mechanism of moving bodies in complex fluids by spatiotemporal symmetry breaking.
Organic fouling development in a direct contact membrane distillation system was investigated with synthetic model solutions of humic acid (HA), alginate acid (AA) and bovine serum albumin (BSA). A ...40–50% flux decline was observed, with BSA and HA showing dominant fouling tendencies, while minimal fouling was observed with AA due to its hydrophilic nature. Based on the feed characterization analysis using liquid chromatography-organic carbon detector, the HA feed solution showed thermal disaggregation to low molecular weight-HA (LMW-HA) organics with increased feed temperature (50°C and 70°C). The HA fouled membrane autopsy analysis showed the penetration of organics through the membrane pores. In comparison, the BSA feed solution showed more significant deposits on the membrane surface (35.2% higher carbon mass compared to HA foulant) with less significant pore penetration. The mixed organic (MO) feed solution consisting of BSA, HA and AA altogether showed evidence of foulant to foulant interaction. The MO feed solution leads to a significant flux decline of 65% only at a later stage upon the disaggregation of LMW-HA organics that adhered on the membrane.
•Organic fouling development in DCMD was investigated with model organic compound.•HA compound thermally disaggregated to LMW-HA organics.•Membrane pore penetration was observed with the presence of LMW-HA organics.•Foulant to foulant interaction was evident in mixed organic feed solution.
Nanoscale memristive devices using tungsten oxide as the switching layer have been fabricated and characterized. The devices show the characteristics of a flux-controlled memristor such that the ...conductance change is governed by the history of the applied voltage signals, leading to synaptic behaviors including long-term potentiation and depression. The memristive behavior is attributed to the migration of oxygen vacancies upon bias which modulates the interplay between Schottky barrier emission and tunneling at the WO
X
/electrode interface. A physical model incorporating ion drift and diffusion effects using an internal state variable representing the area of the conductive region has been proposed to explain the observed memristive behaviors. A SPICE model has been further developed that can be directly incorporated into existing circuit simulators. This type of device can be fabricated with low-temperature processes and has potential applications in synaptic computations and as analog circuit components.
Hot pepper (Capsicum annuum), one of the oldest domesticated crops in the Americas, is the most widely grown spice crop in the world. We report whole-genome sequencing and assembly of the hot pepper ...(Mexican landrace of Capsicum annuum cv. CM334) at 186.6× coverage. We also report resequencing of two cultivated peppers and de novo sequencing of the wild species Capsicum chinense. The genome size of the hot pepper was approximately fourfold larger than that of its close relative tomato, and the genome showed an accumulation of Gypsy and Caulimoviridae family elements. Integrative genomic and transcriptomic analyses suggested that change in gene expression and neofunctionalization of capsaicin synthase have shaped capsaicinoid biosynthesis. We found differential molecular patterns of ripening regulators and ethylene synthesis in hot pepper and tomato. The reference genome will serve as a platform for improving the nutritional and medicinal values of Capsicum species.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Low-pathogenicity avian influenza H9N2 remains an endemic disease worldwide despite continuous vaccination, indicating the need for an improved vaccine strategy. Bacillus subtilis (B. subtilis), a ...gram-positive and endospore-forming bacterium, is a non-pathogenic species that has been used in probiotic formulations for both animals and humans. The objective of the present study was to elucidate the effect of B. subtilis spores as adjuvants in chickens administered inactivated avian influenza virus H9N2. Herein, the adjuvanticity of B. subtilis spores in chickens was demonstrated by enhancement of H9N2 virus-specific IgG responses. B. subtilis spores enhanced the proportion of B cells and the innate cell population in splenocytes from chickens administered both inactivated H9N2 and B. subtilis spores (Spore + H9N2). Furthermore, the H9N2 and spore administration induced significantly increased expression of the pro-inflammatory cytokines IL-1β and IL-6 compared to that in the H9N2 only group. Additionally, total splenocytes from chickens immunized with inactivated H9N2 in the presence or absence of B. subtilis spores were re-stimulated with inactivated H9N2. The subsequent results showed that the extent of antigen-specific CD4
and CD8
T cell proliferation was higher in the Spore + H9N2 group than in the group administered only H9N2. Taken together, these data demonstrate that B. subtilis spores, as adjuvants, enhance not only H9N2 virus-specific IgG but also CD4
and CD8
T cell responses, with an increase in pro-inflammatory cytokine production. This approach to vaccination with inactivated H9N2 together with a B. subtilis spore adjuvant in chickens produces a significant effect on antigen-specific antibody and T cell responses against avian influenza virus.
Summary
Few studies have directly compared the long‐term clinical outcomes of entecavir (ETV) and tenofovir disoproxil fumarate (TDF). This study aimed to compare the risk of mortality, liver ...transplantation and hepatic complications including hepatocellular carcinoma (HCC) and hepatic decompensation between these drugs in treatment‐naïve chronic hepatitis B (CHB). We performed a longitudinal observational analysis of data from 1325 consecutive adult CHB patients with a cumulative adherence of ≥80% to treatment with ETV (n = 721) or TDF (n = 604) at a tertiary referral hospital in Ulsan, Korea, from 1 January 2007 through 31 April 2017. Among the patients, 708 were analysed using propensity score matching with a ratio of 1:1. In the follow‐up period of up to 5 years, five patients (0.4%) died, three patients (0.2%) underwent liver transplantation (LT) and 54 patients (4.1%) developed HCC. Hepatic decompensation occurred in 24 (1.8%) patients. ETV therapy did not significantly differ from TDF therapy regarding the risk of liver‐related death or LT (HR 0.96; 95% CI, 0.23‐4.07; log‐rank P = 0.955), HCC (HR, 1.36; 95% CI, 0.72‐2.56; log‐rank P = 0.340) and hepatic decompensation (HR, 1.64; 95% CI, 0.67‐4.00; log‐rank P = 0.276). In the 708 propensity‐matched pairs, ETV and TDF were also not significantly different with respect to the risk of mortality, LT and hepatic complications. In this longitudinal observational study of 1325 patients with CHB, ETV and TDF therapies were not significantly different regarding the risk of mortality, HCC, LT and hepatic decompensation.
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•KOH was impregnated on rice husk KOH-activated carbon, named as DKOH-AC.•DKOH-AC involved both chemi- and physi-sorption when KOH-AC allowed physi-sorption.•CO2 adsorption on DKOH-AC ...followed Freundlich and pseudo second order models.•DKOH-AC adsorbed 2.1 mmol/g in an indoor condition.
Relatively high indoor CO2 concentration (greater than 1000 ppm) has a negative impact on human health. In this work, a cost-effective CO2 adsorbent (DKOH-AC) was developed by impregnating KOH on rice husk-based KOH activated carbon (KOH-AC, 1439 m2/g). KOH can be successfully loaded on the surface of KOH-AC and significantly changed its surface properties. DKOH-AC still remained a considerable surface area (206 m2/g) and showed a similar Smicro/SBET ratio. In-situ FTIR analysis confirmed that the major CO2 adsorption mechanism of KOH-AC was based on physisorption while that on DKOH-AC involved both chemisorption and physisorption. DKOH-AC showed a higher heat of adsorption (34 ∼ 41 KJ/mol) and gas selectivity (16.6) than these of KOH-AC. KOH-AC quickly reached an adsorption equilibrium (about 50 min) as compared to that of DKOH-AC. In addition, DKOH-AC exhibited an excellent adsorption performance of 2.1 mmol/g for a low concentration of CO2 (2000 ppm ∼ 500 ppm) under indoor conditions. Both the CO2 adsorption isotherm on KOH-AC and DKOH-AC well followed the Langmuir and Freundlich models. The CO2 adsorption kinetics on KOH-AC followed the pseudo-first order model whereas that on DKOH-AC obeyed the pseudo-second order model. The adsorption process was controlled by the intraparticle diffusion combined with the film diffusion model.
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