Optimal Light Research Articles

Light Intensity Enhances the Lutein Production in Chromochloris zofingiensis Mutant LUT-4.

Chromochloris zofingiensis, a unicellular green alga, is a potential source of natural carotenoids. In this study, the mutant LUT-4 was acquired from the chemical mutagenesis pool of C. zofingiensis strain. The biomass yield and lutein content of LUT-4 reached 9.23 g·L-1, and 0.209% of dry weight (DW) on Day 3, which was 49.4%, and 33% higher than that of wild-type (WT), respectively. The biomass yields of LUT-4 under 100, 300, and 500 µmol/m2/s reached 8.4 g·L-1, 7.75 g·L-1, and 6.6 g·L-1, which was 10.4%, 21%, and 29.6% lower compared with the control, respectively. Under mixotrophic conditions, the lutein yields were significantly higher than that obtained in the control. The light intensity of 300 µmol/m2/s was optimal for lutein biosynthesis and the content of lutein reached 0.294% of DW on Day 3, which was 40.7% more than that of the control. When LUT-4 was grown under 300 µmol/m2/s, a significant increase in expression of genes implicated in lutein biosynthesis, including phytoene synthase (PSY), phytoene desaturase (PDS), and lycopene epsilon cyclase (LCYe) was observed. The changes in biochemical composition, Ace-CoA, pyruvate, isopentenyl pyrophosphate (IPP), and geranylgeranyl diphosphate (GGPP) contents during lutein biosynthesis were caused by utilization of organic carbon. It was thereby concluded that 300 µmol/m2/s was the optimal culture light intensity for the mutant LUT-4 to synthesize lutein. The results would be helpful for the large-scale production of lutein.

Evaluation of Chemical and Physical Triggers for Enhanced Photosynthetic Glycerol Production in Different Dunaliella Isolates.

The salt-tolerant marine microalgae Dunaliella tertiolecta is reported to generate significant amounts of intracellular glycerol as an osmoprotectant under high salt conditions. This study highlights the phylogenetic distribution and comparative glycerol biosynthesis of seven new Dunaliella isolates compared to a D. tertiolecta reference strain. Phylogenetic analysis indicates that all Dunaliella isolates are newly discovered and do not relate to the D. tertiolecta reference. Several studies have identified light color and intensity and salt concentration alone as the most inducing factors impacting glycerol productivity. This study aims to optimize glycerol production by investigating these described factors singularly and in combination to improve the glycerol product titer. Glycerol production data indicate that cultivation with white light of an intensity between 500 and 2000 μmol m-2 s-1 as opposed to 100 μmol m-2 s-1 achieves higher biomass and thereby higher glycerol titers for all our tested Dunaliella strains. Moreover, applying higher light intensity in a cultivation of 1.5 M NaCl and an increase to 3 M NaCl resulted in hyperosmotic stress conditions, providing the highest glycerol titer. Under these optimal light intensity and salt conditions, the glycerol titer of D. tertiolecta could be doubled to 0.79 mg mL-1 in comparison to 100 μmol m-2 s-1 and salt stress to 2 M NaCl, and was higher compared to singularly optimized conditions. Furthermore, under the same conditions, glycerol extracts from new Dunaliella isolates did provide up to 0.94 mg mL-1. This highly pure algae-glycerol obtained under optimal production conditions can find widespread applications, e.g., in the pharmaceutical industry or the production of sustainable carbon fibers.

The regulation of photosynthesis and growth of rapeseed seedling by the interaction of red and yellow lights with blue light

The interactive regulation among different lights on plant life-activities has not yet been fully understood. In the study, we investigated the interaction of red light (R) and yellow light (Y) with blue light (B) on growth and photosynthesis of rapeseed seedlings. The results showed Y and R as well as their combination of RY were not beneficial for plant photosynthesis and growth, but a quarter addition of B (RB, YB and RBY) obviously reversed these negative effects, improving stomatal behavior, leaf and root developments, photosynthetic traits, as well as synthesis and transport of photosynthetic products. Available light energy and B intervention together decreased the ratio of chlorophyll b (Chl b) to carotenoid (Car), while the opposite effect was observed in the absence of B treatments. Among the various lights, RY and Y significantly upregulated the majority of genes associated with chlorophyll metabolism, while RB predominantly upregulated genes related to the two photosystems (PS). Conversely, B and YB treatments generally suppressed the expression of these genes. Despite these differences in gene expression, the ratios of PSI/PSII to Chl b/Car were consistently maintained around 0.56 in the RB, YB, and RBY treatments. In contrast, this ratio was higher at 0.64 in the B treatment and lower, at less than 0.44, in the R, Y, and RY treatments. These ratios reflect the balance between light supply and utilization in plants under different lights, where plants under RB, YB, and RBY might achieve optimal light environments, while plants under B and under R, Y, and RY experienced high and low light stress, respectively. In conclusion, all combinations of B with R, Y or RY can be used for rapeseed cultivation, and the ratio of Chl b/Car to PSI/PSII might be an important reference index to select optimal light combinations for crop production.

Synergistic enhancement of pulsed light-induced H2 photoproduction in Chlamydomonas cells by optimal sulfite concentration and light waveform

Pulsed light illumination stands out as a noteworthy technique for photosynthetic H2 production, playing a crucial role in eliminating O2 and activating hydrogenase enzymes. However, further improvements are essential to make H2 photoproduction suitable for future commercial applications. In our study, we observed a distinct enhancement in pulsed light-induced H2 photoproduction in the unicellular green alga Chlamydomonas reinhardtii when treated with the optimal concentration of the mild O2 scavenger Na2SO3. This improvement was a result of reduced O2 content, increased hydrogenase enzyme activity, and suppressed H2-uptake activity. Furthermore, our findings indicate that exposing Na2SO3-treated C. reinhardtii to optimal light waveform continues to significantly boost pulsed light-induced H2 photoproduction, attributed to the alleviation of impaired photosystem II activity. Altogether, the combined application of optimal sulfite concentration and light waveform effectively enhances pulsed light-induced photosynthetic H2 production in the green alga C. reinhardtii.

Enhanced Gene Expression in the Biosynthetic Pathway of 2-Acetyl-1-pyrroline in “Hom Bon” Fragrant Native Rice in Response to Varied Light Wavelength Conditions

The development of the Automated Agricultural Cabinet (AAC) prototype was driven by the goal of improving the aromatic qualities of locally grown rice. This compact prototype, designed with attention, employed Arduino programming to investigate genes related to the production of aromatic compounds in rice seedlings under different light conditions, including red, blue and white light. To ensure the reliability of experiments, a controlled environment was maintained at 25 °C and 75 % humidity, and rigorous testing confirmed precise light intensity measurements within the AAC. Results indicated specific light values: 9.25 ± 0.602 for red light, 11.47 ± 0.055 for blue light and 0.91 ± 0.027 µmol·m−²·s−¹ for white light. The study focused on up-regulated genes in 7-day-old ‘Hom Bon’ rice seedlings, revealing a significant increase in P5CS and 1Δ-pyrroline gene expression. These genes are crucial in the biosynthesis pathway of 2-acetyl-1-pyrroline (2-AP), with P5CS acting as a precursor and 1Δ-pyrroline as the final step. Interestingly, the study discovered that when 7-day-old ‘Hom Bon’ rice seedlings were exposed to both red and blue light, gene expression rose dramatically, contrasting when exposed to white light. This finding demonstrates that the wavelength of light exposure influences gene expression in the 2-acetyl-1-pyrroline (2-AP) biosynthetic pathway of ‘Hom Bon’ rice seedlings throughout the 7-day growth stage. This study demonstrates the feasibility of improving the smell of indigenous rice varieties by changing pre-planting light conditions, giving a promising avenue for increased commercial appeal. Furthermore, this project aims to improve the local community’s financial well-being by supporting better farming methods. HIGHLIGHTS The Automated Agricultural Cabinet (AAC) prototype has the capability to select the optimal light wavelength, inducing the up-regulation of genes associated with the 2-AP biosynthetic pathway in “Hom Bon” a fragrant native rice variety In the fragrant native rice variety “Hom Bon” the up-regulated gene in the direct 2-AP pathway, P5CS, exhibited an expression level that was twice as high as that of the housekeeping gene The red and blue wavelengths directly elevated the expression of up-regulated genes associated with the 2-AP biosynthetic pathway GRAPHICAL ABSTRACT

Efficiency Analysis of a Passive Daylighting System Based on Northern Malaysia’s Climate

Daylighting design strategy is important in order to have adequate lighting source in a room and necessary to decrease energy consumption for artificial lighting. Passive daylighting system utilizes daylight by collecting, reflecting and diffusing the natural light throughout a given area. The purpose for this study is to monitor, compare and analyse an optimum light pipe system design that can scatter daylight into a room based on three case studies. Lighting analysis was conducted using Autodesk 3ds Max Design software throughout the project based on the actual geographical parameters of Universiti Malaysia Perlis, Malaysia and also using the real sun azimuth on working hours. The results were compared according to the respective designs in order to observe the maximum internal illuminance and the average internal illuminance. The results show that the straight geometry with low aspect ratio produces the highest interior light intensity among other light pipe systems and the average internal illuminance values in the room was able to reach the minimum requirement of a small room which is 200 – 500 lux.

Effects of Liquidambar Orientalis Oil on Liver and Kidneys in Heathy Wistar Rats

Background: Nowadays, the tendency towards alternative herbal therapies has increased due to the side effects of drugs. However, since the contents, method of use, dosage and toxic effects of herbal products are not fully known, undesirable situations are occasionally encountered. However, there are many experimental studies on the cytotoxicity of L. orientalis oil, most of these studies are in vivo modelling. In this study, the cytotoxic effects of L. orientalis oil on the liver and kidneys were investigated in healthy rats by oral administered. Methods: The study material consisted of 18 female Wistar albino rats (190-280 g) aged 8-10 weeks. All animals were housed under optimal temperature, light and humidity conditions and fed with normal rat pellet food ad libitum. Housing conditions were checked daily. Three groups were organized as L. orientalis oil, olive oil and control group, respectively. Each group consisted of 6 rats. L. orientalis oil group: L. orientalis oil (150 mg/kg) dissolved olive oil (0.6 mL). Olive oil group: Olive oil (0.6 mL). Control group: Empty gavage. The entire trial was performed by intragastric gavage once a day for 14 days. Result: The obtained data showed that serum biochemical parameters remained within normal ranges in oral use of Liquidambar orientalis oil (150 mg/kg) and did not show any difference with the control and olive oil groups. No pathological changes related to cytotoxicity were found in the samples taken from liver and kidney tissues.

Cention-N: A Review

An ideal material used for restoration should be adhesive, tooth coloured, resistant to wear, nontoxic and biocompatible with the tissue. Various direct filling materials are available in dentistry such as amalgam, glass ionomer cement (GIC) and esthetic composite material, each of them having its advantages and disadvantages hence proper selection of restorative materials will help for its clinical success. Cention-N is a new alkasite, bulk filling, basic tooth-coloured, radiopaque material introduced by Ivoclar Vivadent in 2016. It is a self-curing filling material with optimum light curing. It consists of an isofiller which reduces the polymerization shrinkage and utilizes an alkaline filler which is capable of releasing acid-neutralizing ions. It presents with good mechanical properties and long-term stability due to the cross-linking of methacrylates in the final restoration hence it can be used in load-bearing areas. Cention-N can be efficiently used in pediatric patients as it is moisture resistant and releases fluoride which helps in remineralizing teeth thus preventing secondary caries. The use of caution is restricted in the anterior tooth as it is available only in one shade.

Experimental investigation of a new photoelectrochemical cell design featuring a unique photocathode configuration for solar hydrogen production

The electrodeposition process and the subsequent assessment of a novel cuprous oxide photocathode are conducted for solar light-based hydrogen production. The mesh dome photocathode helps facilitate the optimal light harvesting, enabling the efficient collection of the maximum accessible light from the solar simulator. This particular design also ensures that light reaches the remote surfaces of the photocathode through penetrating the mesh structure. The electrodeposition method is then employed to coat cuprous oxide onto the stainless-steel electrode. The subsequent examination of this photocathode occurs within an alkaline solution of potassium dioxide to assess its performance in hydrogen production. The study investigates the impact of the new design of the mesh photocathode on hydrogen generation rates, as well as related efficiencies of energy and exergy, under varying light angles during daylight hours. The present experimental findings reveal that the maximum rates of hydrogen production, achieved at a 45° tilt light and 0.25 M KOH, are 15.38 μg/s and it is 15.83 μg/s for vertical light positions. Furthermore, the highest recorded system exergy and energy efficiencies under vertical light conditions are 2.19% and 3.20%, respectively, compared to 2.14% and 3.12% at applying tilted light. The new photocathode design contributes to a notable 80.3% improvement in hydrogen generation rate at tilted light angles in comparison to vertical light conditions.

Lights, location, action: Shade avoidance signalling over spatial scales.

Plants growing in dense vegetation stands need to flexibly position their photosynthetic organs to ensure optimal light capture in a competitive environment. They do so through a suite of developmental responses referred to as the shade avoidance syndrome. Belowground, root development is also adjusted in response to aboveground neighbour proximity. Canopies are dynamic and complex environments with heterogenous light cues in the far-red, red, blue and UV spectrum, which can be perceived with photoreceptors by spatially separated plant tissues. Molecular regulation of plant architecture adjustment via PHYTOCHROME-INTERACTING FACTOR (PIF) transcription factors and growth-related hormones such as auxin, gibberellic acid, brassinosteroids and abscisic acid were historically studied without much attention to spatial or tissue-specific context. Recent developments and technologies have, however, sparked strong interest in spatially explicit understanding of shade avoidance regulation. Other environmental factors such as temperature and nutrient availability interact with the molecular shade avoidance regulation network, often depending on the spatial location of the signals, and the responding organs. Here, we aim to review recent advances in how plants respond to heterogenous light cues and integrate these with other environmental signals.

Reinforced nanowrinkle electrospun photothermal membranes via solvent‐induced recrystallization

AbstractWearable photothermal materials can capture light energy in nature and convert it into heat energy, which is critical for flexible outdoor sports. However, the conventional flexible photothermal membranes with low specific surface area restrict the maximum photothermal capability, and loose structure of electrospun membrane limits durability of wearable materials. Here, an ultrathin nanostructure candle soot/multi‐walled carbon nanotubes/poly (L‐lactic acid) (CS/MWCNTs/PLLA) photothermal membrane is first prepared via solvent‐induced recrystallization. The white blood cell membrane‐like nanowrinkles with high specific surface area are achieved for the first time and exhibit optimal light absorption. The solvent‐induced recrystallization also enables the membrane to realize large strength and durability. Meanwhile, the membranes also show two‐sided heterochromatic features and transparency in thick and thin situations, respectively, suggesting outstanding fashionability. The nano‐wrinkled photothermal membranes by novel solvent‐induced recrystallization show high flexibility, fashionability, strength, and photothermal characteristics, which have huge potential for outdoor warmth and winter sportswear.image

The impact of polystyrene nanoplastics (PSNPs) on physiological and biochemical parameters of the microalgae Spirulina platensis

Nanoplastics, as emerging pollutants, have harmful effects on living organisms and the environment, the mechanisms and extent of which remain unclear. Microalgae, as one of the most important biological groups in the food chain and sensitive environmental indicators to various pollutants, are considered a suitable option for investigating the effects of nanoplastics. In this study, the effects of polystyrene nanoplastics on the growth rate, dry weight, chlorophyll a and carotenoid levels, proline, and lipid peroxidation in the Spirulina platensis were examined. Three concentrations of 0.1, 1, and 10 mg L-1 of PSNPs were used alongside a control sample with zero concentration, with four repetitions in one-liter containers for 20 days under optimal temperature and light conditions. Various analyses, including growth rate, dry weight, proline, chlorophyll a and carotenoid levels, and lipid peroxidation, were performed. The results indicated that exposure to PSNP stress led to a significant decrease in growth rate, dry weight, and chlorophyll a and carotenoid levels compared to the control sample. Furthermore, this stress increased the levels of proline and lipid peroxidation in Spirulina platensis. Morphological analysis via microscopy supported these findings, indicating considerable environmental risks associated with PSNPs.

High‐Efficiency Semitransparent Near‐Infrared Organic Photodetectors Enabled by a Molecular Crystal Network

AbstractSemitransparent organic photodetectors (ST‐OPDs) show immense promise for integration into optoelectronic devices, offering adjustable absorption and see‐through functionalities. However, achieving high‐performance ST‐OPDs remains challenging, necessitating a delicate balance of low dark current density, high external quantum efficiency, and optimal visible light transmission. Here, a strategy is presented using anode interfacial materials (AIMs) as the donor and narrow bandgap non‐fullerene acceptors (NFAs) to formulate the donor: acceptor light‐sensitive layer. Critical to the approach is the incorporation of 1,8‐diiodooctane during film processing, enabling the formation of morphology with an NFA molecular crystal network embedded within the donor polymer matrix. This optimized morphology substantially boosted device external quantum efficiency and reduced dark current under reverse bias, yielding a remarkable special detectivity of over 1013 Jones at 840 nm under a bias of −0.1 V. ST‐OPDs are achieved with detectivity surpassing 1012 Jones and notable average visible transmittance of over 50%. These findings highlight the potential of AIM:NFA combinations for high‐efficiency ST‐OPDs by finely controlling morphology through multiple length scales, opening doors for various applications in transparent electronics and beyond.

The effect of near-infrared low-level light on the in vitro quality of platelets during storage.

Near-infrared (NIR) light has been successfully applied to improve the quality of mouse platelets during storage. Because it is suspected that the mitochondria contain the primary photon acceptor, we hypothesized that human platelets for transfusion may be affected similarly and could benefit from NIR light treatment. The optimal light dose was determined using portions of platelet concentrates (PCs) in PAS-E. A pool-and-split design was used to prepare PCs in PAS-E or plasma (n = 6). On day 1, one unit of both pairs was illuminated with 830 nm light (light-emitting diodes, 15 J/cm2). PCs were stored at 22°C and sampled regularly for analysis. Data were compared with their corresponding controls with a paired two-sided t-test. Illuminated platelets in PAS-E were less activated with significantly lower CD62P expression (day 8: 10.8 ± 1.8 vs. 12.2 ± 2.6, p < 0.05) and lower Annexin A5 binding (day 8: 11.8 ± 1.9 vs. 13.1 ± 2.4, ns). They produced significantly less lactate resulting in a higher pH (days 6-10). ATP content and mitochondrial membrane potential were not affected. Although these trends were also observed for PCs in plasma, the differences did not reach statistical significance as compared with the control group. Our study demonstrates that the glycolysis rate of human platelets can be modulated through the use of NIR, possibly through mitochondrial aerobic metabolism, but this requires confirmation. If NIR illumination can be further optimized, it may potentially become a useful tool in situations in which glycolysis and platelet activation are exacerbated.

Twisted leaf like ZnO-flake-like BiOI@CNF grown on ITO substrate as a nanostructured pioneering platform for photoelectrochemical water splitting

Despite ZnO nanostructures garnering significant attention for photoelectrochemical (PEC) water splitting, the quest for efficient ZnO-based photoelectrodes with optimal light absorption, effective electron-hole separation, and transfer remains a challenge. The formation of ZnO heterojunctions with lower bandgap nanostructures of semiconductors has emerged as a strategy to enhance charge transfer while mitigating recombination rates. Additionally, the introduction of carbon nanofibers (CNFs) to these heterojunctions serves to further suppress recombination by electron trapping and enhances catalytic active sites, thereby elevating PEC performance. In this study, twisted leaf-like ZnO, flake-like BiOI, ZnO-BiOI nanostructure heterojunctions, and ZnO-BiOI@C composites were synthesized through a solvothermal method. Notably, the ZnO-BiOI@C photoelectrode exhibited outstanding performance, achieving a photocurrent density of 5.6 mA/cm2 through linear sweep voltammetry under light illumination. Each synthesized photoelectrode demonstrated robust photocurrent responsiveness and excellent stability under chopped conditions for up to 1150 s with a 50 s interval. This remarkable stability is attributed to the unique and stable morphological characteristics and strong crystallinity of the synthesized materials. The formed heterojunction between ZnO-BiOI was found to extend light absorption capabilities, while the incorporation of CNFs effectively trapped electrons from the heterojunction's conduction band, enhancing overall water splitting performance. The results underscore the potential of the ZnO-BiOI@C composite as a high-performing photoelectrode for PEC applications, emphasizing the importance of morphological and compositional considerations in advancing PEC technologies.

Experimentally implemented dynamic optogenetic optimization of ATPase expression using knowledge-based and Gaussian-process-supported models

Optogenetic modulation of adenosine triphosphatase (ATPase) expression represents a novel approach to maximize bioprocess efficiency by leveraging enforced adenosine triphosphate (ATP) turnover. In this study, we experimentally implement a model-based open-loop optimization scheme for optogenetic modulation of the expression of ATPase. Increasing the intracellular concentration of ATPase, and thus the level of ATP turnover, in bioprocesses with product synthesis coupled with ATP generation, can lead to increased substrate uptrake and product formation. Previous simulation studies formulated optimal control problems using dynamic constraint-based models to find optimal light inputs in fermentations with optogenetically mediated ATPase expression. However, using these models poses challenges due to resulting bilevel optimizations and complex parameterization. Here, we outline a simplified unsegregated and quasi-unstructured kinetic modeling approach that reduces the number of dynamic states and leads to single-level optimizations. The models can be augmented with Gaussian processes to compensate for model uncertainties. We implement optimal control constrained by knowledge-based and hybrid models for optogenetic ATPase expression in Escherichia coli with lactate as the main product. To do so, we genetically engineer E. coli to obtain optogenetic expression of ATPase using the CcaS/CcaR system. This represents the first experimental implementation of model-based optimization of ATPase expression in bioprocesses.

Abiotic and biotic factors influencing small-scale corn production along a shade spectrum in arid urban agriculture settings.

Urban agriculture may be an avenue to help alleviate strain on the global production of staple crops like corn (Zea mays), but significant knowledge gaps exist regarding the optimization of staple crop production in urban settings, and especially in arid urban settings where different challenges exist for crop success. We sought to assess abiotic and biotic factors that impact sweet corn production in six arid urban agricultural plots with varying levels of shade stress, a known inhibitor of corn production. Corn successfully reached maturity in 50% of the studied plots (n = 18). Microbial richness and diversity were uniformly high in all plot soils and not indicated as a hinderance to corn production nor correlated with corn success. Multiple corn success metrics were positively correlated with average daytime light intensity (r = 0.74 to 0.84) and soil organic matter (r = 0.77 to 0.89), suggesting that these factors are critical aspects of successful corn production. In plots that did not receive optimal light exposure, exceptional soil health and morning vs afternoon sun exposure offset at least some degree of shade stress in these arid urban environments. Corn success metrics were negatively correlated with soil calcium, magnesium, sodium and sulfate (r = -0.71 to -0.90), suggesting that minimizing or mitigating the buildup of salt constituents in soils is critical for successful corn production. Optimizing staple crop production in arid urban agricultural settings supports food chain stability and social and economic security of local communities. This work suggests abiotic and biotic drivers of corn success which can be utilized for crop optimization in these environments.

Unveiling the Spatiotemporal and Dose Responses within a Single Live Cancer Cell to Photoswitchable Upconversion Nanoparticle Therapeutics Using Hybrid Hyperspectral Stimulated Raman Scattering and Transient Absorption Microscopy.

Photodynamic therapy (PDT) provides an alternative approach to targeted cancer treatment, but the therapeutic mechanism of advanced nanodrugs applied to live cells and tissue is still not well understood. Herein, we employ the hybrid hyperspectral stimulated Raman scattering (SRS) and transient absorption (TA) microscopy developed for real-time in vivo visualization of the dynamic interplay between the unique photoswichable lanthanide-doped upconversion nanoparticle-conjugated rose bengal and triphenylphosphonium (LD-UCNP@CS-Rb-TPP) probe synthesized and live cancer cells. The Langmuir pharmacokinetic model associated with SRS/TA imaging is built to quantitatively track the uptakes and pharmacokinetics of LD-UCNP@CS-Rb-TPP within cancer cells. Rapid SRS/TA imaging quantifies the endocytic internalization rates of the LD-UCNP@CS-Rb-TPP probe in individual HeLa cells, and the translocation of LD-UCNP@CS-Rb-TPP from mitochondria to cell nuclei monitored during PDT can be associated with mitochondria fragmentations and the increased nuclear membrane permeability, cascading the dual organelle ablations in cancer cells. The real-time SRS spectral changes of cellular components (e.g., proteins, lipids, and DNA) observed reflect the PDT-induced oxidative damage and the dose-dependent death pattern within a single live cancer cell, thereby facilitating the real-time screening of optimal light dose and illumination duration controls in PDT. This study provides new insights into the further understanding of drug delivery and therapeutic mechanisms of photoswitchable LD-UCNP nanomedicine in live cancer cells, which are critical in the optimization of nanodrug formulations and development of precision cancer treatment in PDT.

Photocatalytic Nitrate Reduction over TiO2 Layers on Glass Rings Generated by Dip‐Coating

AbstractThe support of powdered catalysts on mold bodies facilitates their handling and reusability. In case of photocatalytic applications, such as enhanced water purification processes, transparent supports with thin layers of the active material are desirable to obtain an optimal light efficiency. For the generation of such layers a precise control of layer thickness is crucial. Here, a multi‐step dip‐coating approach for the generation of TiO2 layers with varying thickness on glass rings is reported. Additionally, the coated glass rings were tested in the photocatalytic reduction of nitrate in aqueous solution under simulated sunlight.

Morphological and physiological responses of the cosmopolitan marine diatom Thalassiosira rotula to acidification

We investigated the effect of decreased pH on the morphology and nutrient physiology of the cosmopolitan marine diatom Thalassiosira rotula (CCMP3362) by acclimating unialgal cultures to two different CO2 gas concentrations under optimal light, temperature and nutrient conditions. At lower pH (higher CO2), T. rotula exhibited a reduction in cell diameter (7%), surface area (13%), and volume (20%), and an increase in surface area-to-volume ratio (7%). All measures of silicification in T. rotula, i.e., silica (SiO2) quota, rate of silicic acid (Si(OH)4) utilization, and elemental ratios of SiO2:C and SiO2:N, remained unchanged. Similarly, carbon (C) and nitrogen (N) quotas, ratios and utilization rates were mostly unaffected by pH. In contrast, the utilization rate of nitrate (ρNO3) was significantly lower at decreased pH when the rate was normalized by cell number instead of by cell volume. The changes in cell morphology found in this study under low pH were likely not large enough to significantly impact physiological processes and the role of this species in marine food webs and biogeochemical cycles. It is possible that the interactive effects of pH, temperature, light, and nutrient availability characteristic of different regions of the world ocean could result in stronger physiological and morphological responses in this widespread diatom. However, under constant optimal growth conditions, T. rotula was only mildly affected by changes in pH, and in particular the physiology and elemental stoichiometry of C, N and Si were not sensitive to acidification.