Perovskite superlattices with efficient carrier dynamics.

Compared with their three-dimensional (3D) counterparts, low-dimensional metal halide perovskites (2D and quasi-2D; B2An-1MnX3n+1, such as B = R-NH3+, A = HC(NH2)2+, Cs+; M = Pb2+, Sn2+; X = Cl-, Br-, I-) with periodic inorganic-organic structures have shown promising stability and hysteresis-free electrical performance1-6. However, their unique multiple-quantum-well structure limits the device efficiencies because of the grain boundaries and randomly oriented quantum wells in polycrystals7. In single crystals, the carrier transport through the thickness direction is hindered by the layered insulating organic spacers8. Furthermore, the strong quantum confinement from the organic spacers limits the generation and transport of free carriers9,10. Also, lead-free metal halide perovskites have been developed but their device performance is limited by their low crystallinity and structural instability11. Here we report a low-dimensional metal halide perovskite BA2MAn-1SnnI3n+1 (BA, butylammonium; MA, methylammonium; n = 1, 3, 5) superlattice by chemical epitaxy. The inorganic slabs are aligned vertical to the substrate and interconnected in a criss-cross 2D network parallel to the substrate, leading to efficient carrier transport in three dimensions. A lattice-mismatched substrate compresses the organic spacers, which weakens the quantum confinement. The performance of a superlattice solar cell has been certified under the quasi-steady state, showing a stable 12.36% photoelectric conversion efficiency. Moreover, an intraband exciton relaxation process may have yielded an unusually high open-circuit voltage (VOC).

Synthesis of a 3D Flower-Like BiOCl/Bi-MOF Heterostructure for High-Performance Removal of Rhodamine B and Tetracycline Hydrochloride.

Semiconductor materials based on bismuth metal have been extensively explored for their potential in photocatalytic applications owing to their distinctive crystal structure. Herein, we present the development of a hybrid photocatalyst, CAU-17/BiOCl, featuring a flower-like nanosheet morphology tailored for the photocatalytic degradation of organic contaminants such as rhodamine B (RhB) and tetracycline hydrochloride (TCH). The composite material is obtained by growing thin CAU-17 layers directly onto the host flower-like BiOCl nanosheets under solvothermal conditions. The optimized CAU-17/BiOCl composite possesses excellent photocatalytic performance, achieving a notable 96.0% removal rate for RhB and 78.4% for TCH after 60 and 90 min of LED light irradiation, respectively. This boosted activity is attributed to the heightened absorption of visible light caused by BiOCl and the provision of additional reaction sites due to the thin CAU-17 layers. Furthermore, the establishment of an S-scheme heterojunction mechanism enables efficient charge separation between CAU-17 and BiOCl, facilitating the separation of photoinduced electrons (e-) and holes (h+). Analysis of the degradation mechanism of RhB and TCH reveals the predominant role of superoxide radicals (•O2-), e-, and h+ in the photocatalytic degradation process. Moreover, the removal efficiency of TCH can reach approximately 64.5% after four cycles of recycling of CAU-17/BiOCl. Our work provides a facile, effective solution and a theoretically explained approach for the effective degradation of pollutants using heterojunction photocatalysts.

Atomic layer deposition of SnS2film on a precursor pre-treated substrate.

Two-dimensional (2D) materials are attracting attention because of their outstanding physical, chemical, and electrical properties for applications of various future devices such as back-end-of-line field effect transistor (BEOL FET). Among many 2D materials, tin disulfide (SnS2) material is advantageous for low temperature process due to low melting point that can be used for flexible devices and back-end-of-line (BEOL) devices that require low processing temperature. However, low temperature synthesis method has a poor crystallinity for applying to various semiconductor industries. Hence, many studies of improving crystallinity of tin disulfide film are studied for enhancing the quality of film. In this work, we propose a precursor multi-dosing method before deposition of SnS2. This precursor pre-treatment was conducted by atomic layer deposition cycles for more adsorption of precursors to the substrate before deposition. The film quality was analyzed by x-ray diffraction, Raman, transmission electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy. As a result, more adsorbates by precursor pre-treatment induce higher growth rate and better crystallinity of film.

The Comparison of Clinical Outcomes in Elderly (≥75 Years) and Non-Elderly (<75 Years) Patients with Acute Cholangitis Due to Choledocholithiasis.

Background and Objectives: Acute cholangitis may be fatal, particularly in elderly patients. According to the Tokyo Guidelines 2018, those aged ≥75 years are classified as moderate (Grade II) severity. However, it has not been established whether age itself is the deciding factor of poor outcomes. We studied the impact of old age (≥75 years) on the mortality and morbidity of acute cholangitis due to choledocholithiasis. Materials and Methods: We retrospectively examined 260 patients with calculous acute cholangitis who had undergone biliary drainage. Patients were divided into two groups: elderly (≥75 years) and non-elderly (<75 years). We aimed to compare organ dysfunction, in-hospital mortality, intensive care unit (ICU) hospitalization, and the severity of acute cholangitis. Results: Of 260 patients, 134 (51.5%) were in the elderly group and 126 (48.5%) were in the non-elderly group. The mean age was 72.3 ± 14.4 years, and 152 (58.5%) were men. The elderly patients showed a higher incidence of shock (12.7% vs. 4.8%, p = 0.029), respiratory dysfunction (7.5% vs. 0%, p = 0.002), and renal dysfunction (8.2% vs. 0.8%, p = 0.006) than the non-elderly patients. The overall in-hospital mortality rate was 2.7%, with no significant differences between the elderly and the non-elderly (4.5% vs. 0.8%, p = 0.121). The incidence of severe acute cholangitis was significantly higher in the elderly group (26.9% vs. 9.5%, p < 0.001). However, there was no significant difference in the rates of ICU hospitalization (9.7% vs. 4%, p = 0.088) and lengths of hospital stay (LOS) (8.3 d vs. 7.1 d, p = 0.086). Conclusions: No difference was observed in the in-hospital mortality, ICU hospitalization, or LOS between the elderly (≥75 years) and the non-elderly (<75 years) with calculous acute cholangitis. However, severe acute cholangitis was significantly more frequent in elderly patients.

Clinical Significance of the Neutrophil-Lymphocyte Ratio as an Early Predictive Marker for Adverse Outcomes in Patients with Acute Cholangitis.

Background and objectives: Acute cholangitis can be life-threatening if not recognized early. We investigated the predictive value of the neutrophil-lymphocyte ratio (NLR) in acute cholangitis. Materials and Methods: We retrospectively evaluated 206 patients with acute cholangitis who underwent biliary drainage. The severity of acute cholangitis was graded according to the Tokyo 2018 guideline. Patients were dichotomized according to the acute cholangitis severity (mild/moderate vs. severe), the presence of shock requiring a vasopressor/inotrope, and blood culture positivity. The baseline NLR, white blood cell (WBC) count, and C-reactive protein (CRP) levels were compared between groups. Results: The severity of acute cholangitis was graded as mild, moderate, or severe in 71 (34.5%), 107 (51.9%), and 28 (13.6%) patients, respectively. Ten patients (4.8%) developed shock. Positive blood culture (n = 50) was observed more frequently in severe acute cholangitis (67.9% vs. 17.4%, p < 0.001). The NLR was significantly higher in patients with severe cholangitis, shock, and positive blood culture. The area under the curve (AUC) for the NLR, WBC, and CRP for severe acute cholangitis was 0.87, 0.73, and 0.74, respectively. The AUC for the NLR, WBC, and CRP for shock was 0.81, 0.64, and 0.67, respectively. The AUC for the NLR, WBC, and CRP for positive blood culture was 0.76, 0.64, and 0.61, respectively; the NLR had greater power to predict disease severity, shock, and positive blood culture. The optimal cut-off value of the baseline NLR for the prediction of severe acute cholangitis, shock, and positive blood culture was 15.24 (sensitivity, 85%; specificity, 79%), 15.54 (sensitivity, 80%; specificity, 73%), and 12.35 (sensitivity, 72%; specificity, 70%), respectively. The sequential NLR values from admission to 2 days after admission were significantly higher in patients with severe cholangitis and shock. Conclusions: An elevated NLR correlates with severe acute cholangitis, shock, and positive blood culture. Serial NLR can track the clinical course of acute cholangitis.

Rough-Surface-Enabled Capacitive Pressure Sensors with 3D Touch Capability.

Fabrication strategies that pursue "simplicity" for the production process and "functionality" for a device, in general, are mutually exclusive. Therefore, strategies that are less expensive, less equipment-intensive, and consequently, more accessible to researchers for the realization of omnipresent electronics are required. Here, this study presents a conceptually different approach that utilizes the inartificial design of the surface roughness of paper to realize a capacitive pressure sensor with high performance compared with sensors produced using costly microfabrication processes. This study utilizes a writing activity with a pencil and paper, which enables the construction of a fundamental capacitor that can be used as a flexible capacitive pressure sensor with high pressure sensitivity and short response time and that it can be inexpensively fabricated over large areas. Furthermore, the paper-based pressure sensors are integrated into a fully functional 3D touch-pad device, which is a step toward the realization of omnipresent electronics.

An Upflow-Type Filtration Device Using Expanded Polypropylene Media (EPM) to Treat First Flush of Rainwater.

The first flush of rainwater in urban areas is highly contaminated and causes adverse effects on both the water environment and ecosystem. In this study, a novel filtration device using expanded polypropylene media (EPM) was developed for efficient control of pollutants in first flush of urban runoff. The effect of foaming ratio on EPM for filtration efficiency and clogging potential was examined under various operating conditions. Experimental results using a laboratory-scale filtration device indicated that the removal efficiencies of suspended solids were initially high (>90% removal until 60 minutes) and decreased with filtration time (60% for EPM15 at 180 minutes and less than 10% for EPM45). Similarly, more than 90% of Cr, Pb, and Zn were removed for EPM15 within 30 minutes and decreased with filtration time. The surface area and specific hydraulic resistance of EPM were sensitive to foaming ratio. Optimum conditions for foaming ratio increased pollutant removal and minimized head loss. A simple model was derived and applied for theoretical analysis of the filtration device with EPM.

Modification of Vermiculite for the Preparation of Floating Adsorbent for Phosphate in Wastewater.

Floating adsorbents made from exfoliated vermiculite (EV) were tested for their ability to remove phosphate in aqueous solution. The modified vermiculites (MEV) were prepared with EV/glycerol ratio of 1/4 where glycerol contained 4 mol% H2SO4 and heated until designated temperatures. The highest specific surface area of 58.6 m(2)/g and carbon content of 62.2% were obtained for MEV heated at 580 °C and 380 °C, respectively. The dry density of MEV was decreased from 1.78 g/cm(3) (EV) to 0.25 g/cm(3), indicating these adsorbent floating characteristic. The MEV heated at 380 °C showed the highest Freundlich partition coefficient of 45.7 L/kg and the highest Langmuir sorption capacity of 714.3 mg/kg among other MEVs (476.2 mg/kg for MEV-580 and 181.8 mg/kg for MEV-780). Removal of phosphate using MEV heated at 380 °C was well explained by pseudo-second-order model and model parameters were comparable to other phosphate adsorption tests.

Inhibition of adipogenesis and leptin production in 3T3-L1 adipocytes by a derivative of meridianin C.

Meridianin C, a marine alkaloid, is a potent protein kinase inhibitor and has anti-cancer activity. We have recently developed a series of meridianin C derivatives (compound 7a-7j) and reported their proviral integration Moloney Murine Leukemia Virus (pim) kinases' inhibitory and anti-proliferative effects on human leukemia cells. Here we investigated the effect of these meridianin C derivatives on adipogenesis. Strikingly, among the derivatives tested, compound 7b most strongly inhibited lipid accumulation during the differentiation of 3T3-L1 preadipocytes into adipocytes. However, meridianin C treatment was largely cytotoxic to 3T3-L1 adipocytes. On mechanistic levels, compound 7b reduced not only the expressions of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), and fatty acid synthase (FAS) but also the phosphorylation levels of signal transducer and activator of transcription-3 (STAT-3) and STAT-5 during adipocyte differentiation. Moreover, compound 7b repressed leptin, but not adiponectin, expression during adipocyte differentiation. Collectively, these findings demonstrate that a meridianin C derivative inhibits adipogenesis by down-regulating expressions and/or phosphorylations of C/EBP-α, PPAR-γ, FAS, STAT-3 and STAT-5.

Construction of BiOCl/bismuth-based halide perovskite heterojunctions derived from the metal-organic framework CAU-17 for effective photocatalytic degradation.

The designed synthesis of an S-scheme heterojunction has possessed a great potential for improving photocatalytic wastewater treatment by demonstrating increased the photoredox capacity and improved the charge separation efficiency. Here, we introduce the fabrication of a heterojunction-based photocatalyst comprising bismuth oxychloride (BiOCl) and bismuth-based halide perovskite (BHP) nanosheets, derived from metal-organic frameworks (MOFs). Our composite photocatalyst is synthesized through a one-pot solvothermal strategy, where a halogenation process is applied to a bismuth-based metal-organic framework (CAU-17) as the precursor for bismuth sourcing. As a result, the rod-like structure of CAU-17 transforms into well-defined plate and nanosheet architectures after 4 and 8 h of solvothermal treatment, respectively. The modulation of the solvothermal reaction time facilitates the establishment of an S-scheme heterojunction, resulting in an increase in the photocatalytic degradation efficiency of rhodamine B (RhB) and sulfamethoxazole (SMX). The optimized BiOCl/BHP composite exhibits superior RhB and SMX degradation rates, achieving 99.8% degradation of RhB in 60 min and 75.1% degradation of SMX in 300 min. Also, the optimized BiOCl/BHP composite (CAU-17-st-8h sample) exhibited the highest rate constant (k = 3.48 × 10-3 min-1), nearly 6 times higher than that of the bare BHP in the photocatalytic degradation process of SMX. The enhanced photocatalytic efficiency can be endorsed to various factors: (i) the in-situ formation of two-components BiOCl/BHP photocatalyst, derived from CAU-17, effectively suppresses the aggregation of pristine BHP and BiOCl particles; (ii) the S-scheme heterostructure establishes a closely-knit interfacial connection, thereby facilitating efficient pathways for charge separation/transfer; and (iii) the BiOCl/BHP heterostructure enhances its capacity to absorb visible light. Our investigation establishes an effective strategy for constructing heterostructured photocatalysts, offering significant potential for application in photocatalytic wastewater treatment.

The effects of nearby trees on the positional accuracy of GNSS receivers in a forest environment.

Global Navigational Satellite System (GNSS) technologies are actively being developed to address the demand for enhanced positional accuracy. Smartphones are the most prevalent GNSS receiver today and have garnered attention thanks to improved positional accuracy and usability that can be accessed at an affordable price. In a forested environment, multipath error can deteriorate the positional accuracy, depending on the state of nearby vegetation. Therefore, this study was conducted to investigate the impacts of the size and location of vegetation on positional accuracy of GNSS receivers to determine whether the errors observed are systematic. Twenty-six control points within the Whitehall Forest GPS Test site in Athens, Georgia were used to evaluate positional accuracy of three different GNSS receivers (two traditional handheld GNSS receivers (including Garmin and Trimble receivers) and a smartphone). Thirty-five forest variables were developed from information around each control point to conduct a correlation analysis with observed horizontal position error in the positions determined by each device. In this study, we confirmed that the positional error of the smartphone was significantly lower than the Garmin receiver, and similar, but significantly different than the positional error observed by the Trimble receiver. It was confirmed that correlations between forest variables and horizontal position error regardless of the GNSS receiver employed were significant, yet trends were not consistent. The effect of the size of nearby trees on horizontal position error could not be generalized; however, the location of nearby trees on horizontal position error could.

Pd nanoparticles decorated BiVO4 pine architectures for photocatalytic degradation of sulfamethoxazole.

Sulfamethoxazole (SMX) has been extensively detected in wastewater treatment plant effluents and surface water. Because of its potential risks to ecology and health, treatment for eliminating SMX is urgently required. In this study, we report the application of Pd nanoparticles decorated on BiVO4 pine architecture for the photocatalytic degradation of SMX. The results showed that the barer BiVO4 and Pd-BiVO4 eliminated SMX under visible-light irradiation. After 210 min of irradiation, 98.8% of SMX was substantially eliminated by Pd-BiVO4, whereas bare BiVO4 can degraded approximately 36.3% of SMX. Pd-BiVO4 also exhibited a high mineralization rate (84% of total organic carbon (TOC) removal) compared to bare BiVO4 (51% of TOC removal). Through three-dimensional excitation-emission matrix fluorescence spectra, SMX with high fluorescence intensity can be degraded to non-fluorescence intermediate products, further confirming the high mineralization of SMX over Pd-BiVO4 catalyst. Well-dispersed Pd nanoparticles on the {040} facet of BiVO4 pine architecture can support the recombination of photogenerated charge carriers because of the formation of the Schottky junction at the Pd-BiVO4 interface. Besides, the active species trapping tests indicated that •O2- and h+ radicals dominate SMX photodegradation over Pd-BiVO4. The main degradation intermediates of SMX in the reaction solution was also identified through ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry analysis. This investigation can provide insight into designing metallic/semiconductor junctions for antibiotic elimination in water media.

New frontiers of invasive plants for biosynthesis of nanoparticles towards biomedical applications: A review.

Above 1000 invasive species have been growing and developing ubiquitously on Earth. With extremely vigorous adaptability, strong reproduction, and spreading powers, invasive species have posed an alarming threat to indigenous plants, water quality, soil, as well as biodiversity. It was estimated that an economic loss of billions of dollars or equivalent to 1 % of gross domestic product as a consequence of lost crops, control efforts, and damage costs caused by invasive plants in the United States. While eradicating invasive plants from the ecosystems is practically infeasible, taking advantage of invasive plants as a sustainable, locally available, and zero-cost source to provide valuable phytochemicals for bionanoparticles fabrication is worth considering. Here, we review the harms, benefits, and role of invasive species as important botanical sources to extract natural compounds such as piceatannol, resveratrol, and quadrangularin-A, flavonoids, and triterpenoids, which are linked tightly to the formation and application of bionanoparticles. As expected, the invasive plant-mediated bionanoparticles have exhibited outstanding antibacterial, antifungal, anticancer, and antioxidant activities. The mechanism of biomedical activities of the invasive plant-mediated bionanoparticles was insightfully addressed and discussed. We also expect that this review not only contributes to efforts to combat invasive plant species but also opens new frontiers of bionanoparticles in the biomedical applications, therapeutic treatment, and smart agriculture.

A critical review on pineapple (Ananas comosus) wastes for water treatment, challenges and future prospects towards circular economy.

Each year, nearly 30 million tons of pineapple fruit are harvested for food and drinking industries, along with the release of a huge amount of pineapple wastes. Without the proper treatment, pineapple wastes can cause adverse impacts on the environment, calling for new technologies to convert them into valuable products. Here, we review the production and application of adsorbents derived from pineapple wastes. The thermal processing or chemical modification improved the surface chemistry and porosity of these adsorbents. The specific surface areas of the pineapple wastes-based adsorbents were in range from 4.2 to at 522.9 m2·g-1. Almost adsorption systems followed the pseudo second order kinetic model, and Langmuir isotherm model. The adsorption mechanism was found with the major role of electrostatic attraction, complexation, chelation, and ion exchange. The pineapple wastes based adsorbents could be easily regenerated. We suggest the potential of the pineapple wastes towards circular economy.

Strain-Driven Negative Resistance Switching of Conductive Fibers with Adjustable Sensitivity for Wearable Healthcare Monitoring Systems with Near-Zero Standby Power.

Recently, one of the primary concerns in e-textile-based healthcare monitoring systems for chronic illness patients has been reducing wasted power consumption, as the system should be always-on to capture diverse biochemical and physiological characteristics. However, the general conductive fibers, a major component of the existing wearable monitoring systems, have a positive gauge-factor (GF) that increases electrical resistance when stretched, so that the systems have no choice but to consume power continuously. Herein, a twisted conductive-fiber-based negatively responsive switch-type (NRS) strain-sensor with an extremely high negative GF (resistance change ratio ≈ 3.9 × 108 ) that can significantly increase its conductivity from insulating to conducting properties is developed. To this end, a precision cracking technology is devised, which could induce a difference in the Young's modulus of the encapsulated layer on the fiber through selective ultraviolet-irradiation treatment. Owing to this technology, the NRS strain-sensors can allow for effective regulation of the mutual contact resistance under tensile strain while maintaining superior durability for over 5000 stretching cycles. For further practical demonstrations, three healthcare monitoring systems (E-fitness pants, smart-masks, and posture correction T-shirts) with near-zero standby power are also developed, which opens up advancements in electronic textiles by expanding the utilization range of fiber strain-sensors.

Strain-Insensitive Stretchable Fiber Conductors Based on Highly Conductive Buckled Shells for Wearable Electronics.

Based on their high applicability to wearable electronics, fiber-based stretchable electronics have been developed via different strategies. However, the electrical conductivity of a fiber electrode is severely degraded, following deformation upon stretching. Despite the introduction of conductive buckled structures to resolve this issue, there still exist limitations regarding the simultaneous realizations of high conductivity and stretchability. Here, we exploit the dense distribution of the Ag nanoparticle (AgNP) network in polyurethane (PU) to fabricate a strain-insensitive stretchable fiber conductor comprising highly conductive buckled shells via a facile chemical process. These buckled AgNPs/PU fibers exhibit stable and reliable electrical responses across a wide range (tensile strain = ∼200%), in addition to their high electrical conductivity (26,128 S/m) and quality factor (Q = 2.29). Particularly, the negligible electrical hysteresis and excellent durability (>10,000 stretching-releasing cycles) of the fibers demonstrate their high applicability to wearable electronics. Furthermore, we develop buckled fiber-based pH sensors exhibiting stable, repeatable, and highly distinguishable responses (changing pH is from 4 to 8, response time is 5-6 s) even under 100% tensile strain. The buckled AgNPs/PU fibers represent a facile strategy for maintaining the stable electrical performances of fiber electrodes across the strain range of human motion for wearable applications.

Fluorescent-based biodegradable microneedle sensor array for tether-free continuous glucose monitoring with smartphone application.

Continuous glucose monitoring (CGM) allows patients with diabetes to manage critical disease effectively and autonomously and prevent exacerbation. A painless, wireless, compact, and minimally invasive device that can provide CGM is essential for monitoring the health conditions of freely moving patients with diabetes. Here, we propose a glucose-responsive fluorescence-based highly sensitive biodegradable microneedle CGM system. These ultrathin and ultralight microneedle sensor arrays continuously and precisely monitored glucose concentration in the interstitial fluid with minimally invasive, pain-free, wound-free, and skin inflammation-free outcomes at various locations and thicknesses of the skin. Bioresorbability in the body without a need for device removal after use was a key characteristic of the microneedle glucose sensor. We demonstrated the potential long-term use of the bioresorbable device by applying the tether-free CGM system, thus confirming the successful detection of glucose levels based on changes in fluorescence intensity. In addition, this microneedle glucose sensor with a user-friendly designed home diagnosis system using mobile applications and portable accessories offers an advance in CGM and its applicability to other bioresorbable, wearable, and implantable monitoring device technology.

Direct gravure printing of silicon nanowires using entropic attraction forces.

The development of a method for large-scale printing of nanowire (NW) arrays onto a desired substrate is crucial for fabricating high-performance NW-based electronics. Here, the alignment of highly ordered and dense silicon (Si) NW arrays at anisotropically etched micro-engraved structures is demonstrated using a simple evaporation process. During evaporation, entropic attraction combined with the internal flow of the NW solution induced the alignment of NWs at the corners of pre-defined structures, and the assembly characteristics of the NWs were highly dependent on the polarity of the NW solutions. After complete evaporation, the aligned NW arrays are subsequently transferred onto a flexible substrate with 95% selectivity using a direct gravure printing technique. As a proof-of-concept, flexible back-gated NW field-effect transistors (FETs) are fabricated. The fabricated FETs have an effective hole mobility of 17.1 cm(2) ·V(-1) ·s(-1) and an on/off ratio of ~2.6 × 10(5) .

Effects of the induction of anoxia in photobioreactor on effective cultivation of Scenedesmus acuminatus under mixotrophic cultivation mode.

The purpose of this study was to investigate the optimum conditions of several factors (i.e. types and concentration of acetate, aeration rate, pH control) for maximizing the mixotrophic cultivation of Scenedesmus acuminatus using acetate as an organic carbon source. When acetate was used, dissolved oxygen (DO) was quickly consumed and resulted in an anoxic condition for 52 h. Then, DO increased quickly by photosynthetic reaction. Whenever we put acetate in a reactor after DO was recovered to higher than 7 mg/L, cells were quickly grown via cell respiration, which subsequently resulted in an anoxic condition. Compared to aeration, ammonium acetate, ammonium acetate with aeration tests, the highest maximum biomass productivity of 0.73 g/L/d was obtained for pH control test with ammonium acetate dosage. From this study, we found that DO was essential for the fast assimilation of acetate and depleted DO was quickly regenerated for pH control test. From this fact, we found that pH control test with ammonium acetate dosage was the best cultivation method for Scenedesmus acuminatus under mixotrophic condition. These findings could be a useful reference for maximizing the cultivation of S. acuminatus in industrial-scale applications.

Urban land use cover changes in three developed cities of the United States: San Diego, Denver, and Buffalo.

Using imagery available through Google Earth Pro and a point sampling methodology, changes in land cover for three U.S. cities were assessed, beginning during the Great Recession (2007) and extending through to 2018. The cities were Buffalo (New York), Denver (Colorado), and San Diego (California), and 11 land cover classes were used to characterize each. The novel contributions of this work, and the innovative contributions to science include an analysis of urban land cover change in the years since the Great Recession, and the use of point pattern analysis on sample points that changed from non-developed in 2007 to developed in 2018, to determine whether a spatial pattern of land cover class change was evident. An initial assumption was made that forest cover change in these three cities would be minimal since the Great Recession. In fact, forest cover decreased by less than 1% in all three cities with the greatest decrease in Buffalo. Over the post-recession study period, increases in the developed land classes were evident in all three cities at the expense of grasses, tree cover, and other land classes. Some clustering of new development activities was noticed at a relatively small scale in San Diego, while some dispersion of new developed activities was noticed at a larger scale in Denver. Among other factors, changes in population, economics, and land use are factors that influence land cover change with specific impacts on forest cover, and therefore in the provision of urban forest benefits to the environment and society.