Change In Color Research Articles

EXPEDIENT REGENERATION PERIODS FOR NITROCELLULOSE POWDER CHARGES WITH LONG SHELF LIFE AND THE DURATION OF THE POST- REGENERATION PERIOD OF THEIR LIFE CYCLE

Currently, a problem in many countries of the world is the presence in arsenals, bases and warehouses of a large number of various ammunition that are beyond the guaranteed storage period. The lack of ammunition production capacity in Ukraine has led to the fact that currently there are ammunition in use whose storage time exceeds 30 years. An analysis of the research showed that after 25 years of storage, due to changes in the energy characteristics of the powder charge, changes occur in the ballistic characteristics of the weapon, which cannot be corrected by introducing amendments to the firing settings. The question arises about the advisability of using such ammunition, both in accurately performing fire missions and operating weapons in general, and in the field of personnel safety. The complex problem of assessing the state of charges is shown, associated with the lack in the state of a reliable system for monitoring the state of powder charges of ammunition, the development of technology for their regeneration, disposal and the possibility of using it for its intended purpose. The first of these problems is key, since the further extension of the life cycle of ammunition depends on its results. Experimental studies have confirmed that changes in the chemical composition of nitrocellulose powders are observed during long-term storage. The change in color of the powder elements confirms the chemical reactions occurring in them with a gradual decrease in their mass. It is presented that during the regeneration process the mass of the powder charge increases by 3 % by saturating the nitrocellulose with hydrogen. The priority time frames for when regeneration gives the maximum effect are graph- ically shown. Analyzing the results of the study, using the ammunition operation model, it was proposed for the first time to use a period after regeneration in the life cycle of powder charges, which makes it possible to determine the time of expedient restoration of the characteristics of gunpowder. It will fluctuate a little for different batches of gunpowder, but, with reasonable probability, its time frame can be determined at 25–27 years. It is predicted that it will be possible to technologically increase the effect of regeneration to 5 %. This will correspond to the restoration of properties to the level of guaranteed operation and a further extension of the operation of the gunpowder by 2 times.

Green Synthesis of Silver Nanoparticles using Cardiospermum Halicacabum Leaf Extract and its Effect on Human Colon Carcinoma Cells

Nanobiotechnology is an evolving domain of scientific exploration connected with synthesis and mechanism of nanoparticles in biological systems. Silver nanoparticles have gained utmost popularity because of its characteristics like thermal conductivity, chemical stability, and high catalytic activities. It also has various advantages like being a drug carrier, transmembrane deliver and potential for controlled intracellular drug-delivery. The current study deals with fabrication of nanoparticles which are formed from biologically reduced silver, followed by its characterization. In addition, anticancer activity was investigated using in-vitro cell model. The synthesis was confirmed from the change in color to brown from golden yellow and also from absorbance peak obtained at 430nm in UV-Vis spectrophotometry. The obtained nanoparticle had an average size of about 150.1 nm and its FTIR peaks suggested the presence of flavonoids and polyphenols. XRD analysis exhibited peaks in the 2θ range of 227.72o, 32.29o, 38.76o, 43.17o, 54.47o, 64.04o and 77.75o, is confirming its crystallographic nature. Further, anticancer activity of silver nanoparticles was tested through cell proliferation assays, Lactate Dehydrogenase assays, and apoptosis assay using Hoechst/PI staining, wherein there is clear reduction in cell’s proliferation, viability, and LDH release, followed by increased dead cells as a result of treatment.

Chemical and physical changes induced by cold plasma treatment of foods: A critical review.

Cold plasma treatment is an innovative technology in the food processing and preservation sectors. It is primarily employed to deactivate microorganisms and enzymes without heat and chemical additives; hence, it is often termed a "clean and green" technology. However, food quality and safety challenges may arise during cold plasma processing due to potential chemical interactions between the plasma reactive species and food components. This review aims to consolidate and discuss data on the impact of cold plasma on the chemical constituents and physical and functional properties of major food products, including dairy, meat, nuts, fruits, vegetables, and grains. We emphasize how cold plasma induces chemical modification of key food components, such as water, proteins, lipids, carbohydrates, vitamins, polyphenols, and volatile organic compounds. Additionally, we discuss changes in color, pH, and organoleptic properties induced by cold plasma treatment and their correlation with chemical modification. Current studies demonstrate that reactive oxygen and nitrogen species in cold plasma oxidize proteins, lipids, and bioactive compounds upon direct contact with the food matrix. Reductions in nutrients and bioactive compounds, including polyunsaturated fatty acids, sugars, polyphenols, and vitamins, have been observed in dairy products, vegetables, fruits, and beverages following cold plasma treatment. Furthermore, structural alterations and the generation of volatile and non-volatile oxidation products were observed, impacting the color, flavor, and texture of food products. However, the effects on dry foods, such as seeds and nuts, are comparatively less pronounced. Overall, this review highlights the drawbacks, challenges, and opportunities associated with cold plasma treatment in food processing.

Application of electron beam irradiation and mild thermal treatment of Bacillus cereus spores in Chinese braised beef cuisine

ABSTRACT The individual and combined effects of electron beam (EB) irradiation and thermal treatments were investigated on Chinese braised beef samples inoculated with Bacillus cereus spores. Log reductions of 1.19, 2.10, and 3.62 log CFU/g were recorded for B. cereus spores after 6, 9, and 12 kGy lone EB doses, respectively. An 85°C thermal treatment at 20 min (H) reduced the spores population by 1.03 log CFU/g. The combination of the thermal and EB irradiation treatments (HEB) of HEB-6 and HEB-9 achieved 1.69 and 2.89 log CFU/g reductions, respectively. The B. cereus spores population was depleted to below the detection limit following HEB-12 treatment. No significant pH change was observed in the treatments except for HEB-12. The hurdle treatment of HEB-12 caused marked changes in color, aroma, and overall acceptability. Although HEB irradiation improved microbial safety, careful selection of approved EB doses can effectively enhance food safety and maintain reasonable quality standards.

Study of Electrochromic Properties of PEDOT:PSS for Tunable Filter Optics with Lithium Salt Electrolyte

Nowadays, conductive polymers based on poly(3,4-ethylenedioxythiophene), poly(styrene sulfonic acid), or PEDOT:PSS, have been employed as a flexible and transparent coating in various significant electronic applications. With the demand for electrochromic properties, such as in electronic displays, further research into its electrooptic properties is required, especially the systematic understanding to obtain the optimized switching. Our research investigates the electrooptic properties of the PEDOT:PSS film, particularly the refractive index changing under various applied biases. The electrochromic device is prepared in a simple fashion, and the electroactive layer of PEDOT:PSS thickness is defined via spin-coating between two indium tin oxide (ITO) substrates. To increase the switching properties of PEDOT:PSS, lithium perchlorate (LiClO4) was prepared in acetonitrile, as the electrolyte in varied concentrations of 1.195 M, 1.5 M, and 2.0 M, respectively. A potential voltage of -4.0 V to 0.0 V is utilized to study the device's electrochromic properties with the step 5 mV/s continuously. Finally, the optical properties are characterized using the spectroscopy method based on real-time measurement of the transmission spectrum and transmission matrix calculations. The change in visible light absorption, transmission, and film color is recorded under a switching cycle that shows consistent behavior. This allows the further utilization of such a hybrid structure for possible tunable filter applications. Keywords: Electrochromic, PEDOT:PSS, Optical, Lithium salt, Electrolyte

The effect of different LED wavelengths used in the cultivation of Pleurotus ostreatus on quality parameters of the mushroom during the storage process

This study aimed to investigate the effects of light emitting diodes (LEDs) of different wavelengths (white, red, blue and green) used in Pleurotus ostreatus cultivation on post-harvest mushroom quality, storage process and maintenance of mushroom quality characteristics during storage. The mushroom was exposed to different LED wavelengths for 8 and 12 h per day during fructification period. The effects of these treatments were observed during post-harvest and storage periods, focusing on changes in color, weight loss, antioxidant capacity (FRAP), and total phenolic content (TPC). The harvested mushrooms were stored at 1 °C for 12 days, and samples were taken every 4 days to analyze mentioned parameters. After harvest, L*,a*,b* values of the fruiting bodies grown under different LEDs ranged 56.5 − 69.8, 2.0 − 3.84, 12.2 − 15.9 respectively, whereas TPC and FRAP values varied from 54.4 to 78.5 mg GAE/100 g fw and 6.14 to 7.59 µmol TE/g fw, respectively. The values of L*, a*, b*, browning index (BI), and yellowness index (YI) demonstrated a clear postponement of discoloration in the samples exposed to 8 h of red LED and 12 h of green LED compared to the control group at the end of the storage period. The TPC of the fruitbody cultivated under red LED (8 h per day) was markedly increased after 12 days (54.4 to 95.1 mg GAEs/100 g fw), but LEDs did not affect the maintenance of antioxidant capacity in P. ostreatus. The results showed that red LED applied for 8 h per day during the fructification period enhanced TPC with minimal effects on the color during cold storage.

Highly Selective Protic-Solvent-Mediated Organic-Inorganic Hybrid Cuprous Bromides Achieving Structural Transformation.

The potential application of stimuli-responsive hybrid copper halides in information storage and switch devices has generated significant interest. However, their transformation mechanism needs to be further studied deeply. Herein, two zero-dimensional (0D) organic-inorganic hybrids, namely, (TBA)CuBr2 (1) with linear [CuBr2]- units and (TBA)2Cu4Br6 (2) with [Cu4Br6]2- clusters (TBA+ = (C4H9)4N+), are synthesized using simple solvent evaporation approaches. Interestingly, upon exposure to distinct protic solvents, such as methanol, ethanol, ethylene glycol, or hot water, 1 undergoes a transformation into 2 with varying degrees of transition, accompanied by a change in luminescence color from cyan to orange (or mixed color) under high-energy emission (e.g., 254 nm) excitation. Hot water can trigger 1 to completely transform into 2 because of its large contact angle difference in the solvents. Furthermore, 2 can be converted back to 1 through a simple solid-state mechanochemical reaction. Additionally, the structure of 2 remains unchanged even after immersion in 80 °C H2O for 168 h due to the dense organic framework. This study provides valuable insights for exploring reversible structural transformation materials in the 0D metal halide system.

A review on improving the sensitivity and color stability of naturally sourced pH-sensitive indicator films.

Naturally sourced pH-sensitive indicator films are of interest for real-time monitoring of food freshness through color changes because of their safety. Therefore, natural pigments for indicator films are required. However, pigment stability is affected by environmental factors, which can in turn affect the sensitivity and color stability of the pH-sensitive indicator film. First, natural pigments (anthocyanin, betalain, curcumin, alizarin, and shikonin) commonly used in pH-sensitive indicator films are presented. Subsequently, the mechanisms behind the change in pigment color under different pH environments and their applications in monitoring food freshness are also described. Third, influence factors, such as the sources, types, and pH sensitivity of pigments, as well as environmental parameters (light, temperature, humidity, and oxygen) of sensitivity and color stability, are analyzed. Finally, methods for improving the pH-sensitive indicator film are explored, encapsulation of natural pigments, incorporation of a hydrophobic film-forming matrix or function material, and protective layer have been shown to enhance the color stability of indicator films, the addition of copigments or mental ions, blending of different natural pigments, and the utilization of electrospinning have been proved to increase the color sensitivity of indicator films. This review could provide theoretical support for the development of naturally sourced pH-sensitive indicator films with high stability and sensitivity and facilitate the development in the field of monitoring food freshness.

Variability of agromorphological traits in Portulaca grandiflora through induced mutation using colchicine

Abstract. Aisyah SI, Meiningrum NI, Yudha YS, Nurcholis W. 2024. Variability of agromorphological traits in Portulaca grandiflora through induced mutation using colchicine. Biodiversitas 25: 2484-2493. Portulaca grandiflora Hook is an ornamental plant originating from the Portulacaceae family, and it has been extensively cultivated on various continents. P. grandiflora displays appealing flower shapes and vibrant colors suitable for growth in a tropical landscape. Increased morphological diversity carries significant importance in the aesthetic function of ornamental plants. The higher the variation in the morphological characteristics of ornamental plants, the greater the market value of these plants due to their enhanced aesthetic appeal. Additionally, colchicine, a polyploidy-inducing agent, can enhance the plant genetic diversity. This study aims to investigate the impact of colchicine application on the morphological characters of P. grandiflora. The experiment was conducted for four months at the Leuwikopo Experimental Field, IPB, with two factors of Completely Randomized Block Design: The colchicine treatment comprises five concentration levels (0, 0.05, 0.1, 0.15, and 0.2), with four test genotypes: Orange, Peach, Bicolor, and Banana. A significant reduction in growth was observed in the Bicolor genotype, followed by the Banana genotype, indicating varying tissue sensitivities to colchicine treatment. The study reveals variations in morphological responses for each concentration treatment and genotype used. Statistical results confirm aspects: (i) each genotype displays different performance, (ii) the combined treatment of colchicine significantly influences the growth and development of quantitative traits, and (iii) The interaction (colchicine x genotype) was statistically significant for all quantitative characters of P. grandiflora except stem diameter. Qualitative traits, such as morphological changes in stem color, leaf color, and shape, were observed. Three correlation values are positive and statistically significant: plant length and leaf width, number of branches on shoots and leaves, and number of branches on shoots and flowers. Putative mutants of P. grandiflora exhibiting new traits require in-depth exploration in subsequent generations.

Tailoring bisindolyl methane derivatives for dual applications: Substituent-directed probing of cyanide ions and anti-tubercular activity

A pair of bisindolyl methane (BIM) compounds (1 and 2) were designed and their colorimetric response towards cyanide (CN−) ions were investigated in detail. In aqueous medium, the compound with single nitro-substituent (1) showed blue-shifted absorption maxima upon addition of cyanide ion, resulting in change in solution color from pink to yellow. On the contrary, the compound with three nitro functional groups (2), exhibited hypochromic shift along with initial, blue-shifted absorption maxima (color changed from pink to yellow to colourless). The mechanistic investigation indicated that the former observation could be attributed by cyanide-mediated hydrogen bonding interaction (or deprotonation), while the latter might be caused due to the Michael addition reaction. Interestingly, at alkaline pH, chemodosimetric interaction was observed with both the probe molecules. However, the rate of interaction was much faster for compound 2 than that observed for 1. A change in the mode of binding of a specific analyte, merely by changing the number of un-reactive substituents, is not much known in the literature. However, it will be extremely beneficial for future engineering of more efficient sensory systems. Furthermore, a library of BIM compounds with various number of nitro groups at different positions (total twelve) were synthesized for evaluation of anti-tubercular activity. Fortunately, some of the compounds were found to be as equally effective as the commercially available anti-tuberculosis drug, ethambutol (MIC: 1.56 µg/mL), whereas the compound 2 displayed a better anti-tubercular response (MIC: 0.78 µg/mL). This observation was further rationalized by docking studies with M. tuberculosis DprE1 in complex with the non-covalent inhibitor QN118.

MANFAAT AKTIVASI FLY ASH BATU BARA DENGAN VARIASI KONSENTRASI NAOH SEBAGAI ADSORBEN

Water is one of the most important natural resources for human life. However, there are some problems that cause water to get polluted and not be used properly, one of which is the liquid waste of the hydrocarbon industry. Fly ash is a residue from coal combustion. Fly ash can be used as an adsorbent to reduce the content of hazardous fluid waste that could threaten human life. The study aims to find out the best NaOH concentration ratio between 1 M and 3 M added to activate fly ash against COD decrease, BOD, TSS, pH, and color change in Kutawaru Cilacap battery waste. The study passes through several stages, namely the first phase of activation of fly ash with NaOH at concentration ratios of 1M and 3M with a ratio of 1:5 for 3 hours. Then, in the adsorption process, the activated fly ash is mixed with battery liquid waste. The final phase is the testing of batik waste at the DLH Cilacap. The results obtained are at the concentration of 1M NaOH because it can reduce COD, BOD, and TSS up to 76%. With the result of COD of 3286 mg/L, BOD of 4921 mg/L, and TSS of 115 mg/L, whereas the results of concentration 3M, with COD of 3615 mg/L, COD 5397 mg/L, and TSS of 36 mg/L, PH for both these concentrations of 8 and the change in color of waste batik that remains black concentrated.

Multiresponsive Bilayer Hydrogel Actuator with Switchable Shape Morphing Capability and Visible Color/Fluorescence Change.

Bilayer hydrogels, endowed with multiresponsive and switchable color-changing properties, have garnered significant attention for bioinspired artificial intelligent materials. However, the design and fabrication of such hydrogels that can fully mimic the adaptation of the live organism, i.e., simultaneous changes in shape, fluorescent, and/or visible color, still remain significant challenges. Herein, a multiresponsive (e.g., temperature, salt, and pH) and multiadaptive (shape, fluorescent color, and visible color changes) hydrogel was fabricated by employing monomers featuring pH-responsive fluorescence 4-(2-(4-(dimethylamino) phenyl)-1-isocyanovinyl) phenol (DP) and switchable color-changing 4-(2-sulfethyl) -1-(4-vinylbenzyl) pyridinium betaine (VPES). The bilayer hydrogel comprises a temperature- and pH-responsive gel layer, poly(N-isopropylacrylamide-co-2-(dimethylamino) ethyl methacrylate), along with a pH-, temperature-, and salt-responsive gel layer, poly(acrylamide-co-2-(dimethylamino)ethyl methacrylate-co-VPES)@DP. Due to the opposite swelling/shrinking behavior between the two layers, the prepared hydrogel exhibits shape changes in response to thermal, salt, and pH stimuli, along with switchable fluorescent color and visible color change that originate from DP and polyVPES, respectively. Apart from multiresponsive behavior, this hydrogel also shows an excellent antifatigue property and high sensitivity, which makes it hold significant potential in many applications. We anticipate that this strategy to realize multiresponsive capability in this work can also inspire the design of the biomimetic smart materials.

Evaluation of staining potential of Silver Diamine Fluoride, Potassium Iodide, Nanosilver Fluoride: an in vitro study

BackgroundThe black staining effect of silver-containing solutions for use to arrest caries can have a negative aesthetic impact on children and parents. This study aims to assess the staining effects of Silver Diamine Fluoride/Potassium Iodide (SDF/KI), SDF and Nanosilver Fluoride (NSF).Materials and methodsForty-four extracted carious primary molars were collected and randomly divided into four groups (n = 11). The carious tissue in all teeth was removed using a chemo-mechanical caries removal agent with an excavator. After caries removal in all groups, SDF, SDF/KI, and NSF were applied to the different groups, while no solution was applied to the control group. Subsequently, the teeth in all groups were restored with compomer. Color values L*, a* and b* were measured using a spectrophotometer at three time points: immediately after compomer restoration (T0), one week later (T1), and four week later (T2). Changes in brightness (ΔL) and color (ΔE) over time were calculated and comparisons among groups were made.ResultsThe SDF solution induced statistically significant black staining (p = 0.013) and a decrease in L* value (p < 0.001) on the compomer material compared to the other groups over time.ConclusionsIt was observed that SDF/KI has the potential to reduce the black staining effect of SDF, though not entirely. Novel experimental solutions like NSF may offer an alternative to counteract the staining effect of SDF.

Targeted metabolomics revealed the seasonal plasticity of skin color and pigment metabolites in ornamental koi carp

The koi carp is an ornamental fish that was obtained through artificial selection from the common carp (Cyprinus carpio L.). The most economically important traits of koi are their beautiful skin patterns in bright colors. As seasonality is an important factor in the biology and ecology of fish, we thus assumed that seasonal changes are involved in regulating the formation of skin color and patterns of koi carp. The white, red, cyan, and black skin colors from four varieties of scaleless koi carp (Doitsu Shiromuji (W), Doitsu Kohaku (WR), Doitsu Showa Sanke (WRI), and Kumonryu (WI)) were evaluated using the CIELab color space (lightness, redness, and yellowness) in different seasons. Compared to winter, the yellowness of the white color in all koi varieties decreased in summer and autumn. The black skin color areas in WRI and WI koi increased in summer and autumn compared to winter. The yellowness of the red color decreased only in WRI koi, while no changes were observed in WR koi. Targeted metabolomics analysis revealed that the levels of the structural pigment guanine of all koi varieties showed significant seasonal variation. Of seven detected carotenoids, the zeaxanthin and tunaxanthin contents in W, WI, and WRI koi changed with the seasons, while none of the carotenoids in WR koi were altered. Of the seven potential regulatory metabolites, epinephrine, melatonin, and cyclic adenosine monophosphate (cAMP) in all four koi varieties showed the highest levels in winter. A correlation analysis suggested that the seasonal changes in white skin color occurred through the epinephrine-cAMP pathway; melanin-dependent and carotenoid-dependent skin color changes occurred through melatonin in koi carp. This study demonstrated the seasonal plasticity of skin color in koi carp regulated by melatonin and epinephrine, associating with variety and color specificity.

Molecular characterization of Sweet potato feathery mottle virus and sweet potato yield loss due to its infection

Abstract. Wirya GNAS, Selangga DGW, Listihani L, Temaja IGRM, Sudiarta IP. 2024. Molecular characterization of Sweet potato feathery mottle virus and sweet potato yield loss due to its infection. Biodiversitas 25: 2355-2362. Sweet potatoes are one of the main sources of carbohydrates for Balinese. "Nasi selo," one of Bali's specialties, uses sweet potato as one of its main ingredients. For the past few years, cultivated sweet potatoes in Bali, Indonesia, manifested symptoms of diseases, particularly purple ring spots, occurring on its young and old leaves. The causative agent of the purple ring symptom is still unknown. Therefore, this study aims to analyze the molecular characteristics of SPFMV Bali isolate and the yield loss estimation it causes. Research methods that were used in this study are survey, sampling, virus identification with RT-PCR using universal Potyvirus as its primer, and field observation to assess the yield loss estimation. Field observation was conducted in five districts in Bali province: Badung, Gianyar, Bangli, Karangasem, and Klungkung. The result indicates that SPFMV infection has been found in these 5 districts, with the highest incidence and severity occurring in Bangli at 86% and 53%. The nucleotide homology of the SPFMV Bali isolates gene has the closest genetic relationship with isolates found in South Korea (MH388494, MH388494) and East Timor (MF572056), at &gt;99%. Based on the latest phylogroup classification, SPFMV is categorized into phylogroups A and B. Phylogroup A consists of SPFMV with O-I strain, O-II strain, and EA strain; phylogroup B only consists of SPFMV with RC strain. Isolate SPFMV found in Bali, has an O strain that belongs to the same group as the O-I strain, also seen in South Korea, East Timor, and China. Actual yield loss that was found by comparing sweet potatoes suffering from purple rings symptom with the one without purple rings symptom reveals a yield loss of 50.9%. Harvested sweet potatoes with purple ring symptoms showed quality deterioration in malformation, discoloration, hollowing, and changes in color and shape. Yield loss of up to 29.53% in fields with a disease severity of 53% has caused a loss of IDR 2,105,166.

Colorimetric sensing based on silver nanoparticle-functionalized copper porphyrin nanozyme for glyphosate

Glyphosate, a widely used herbicide due to the broad-spectrum and high-efficiency properties, has the potential to accumulate in the human body via agricultural food and water sources throughout the food chain. Its safety for both human health and aquatic ecosystems remains a topic of significant debate. In this study, the presence of glyphosate could be directly detected through a notable colorimetric change in an aqueous solution. For this purpose, a silver nanoparticle-functionalized copper porphyrin metal-organic framework (AgNPs/Cu-TCPP) nanozyme was conveniently prepared for colorimetric sensing of glyphosate. The as-synthesized nanozyme that modified AgNPs with Cu-TCPP metal-organic framework as the precursor, has excellent peroxidase mimetic activity and specific recognition performance of glyphosate. The nanozyme demonstrated the ability to catalyze the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) using H2O2, resulting in a marked change in color. When glyphosate was added, which bonded with Cu2+, led to the occupation of the surface-active sites of the nanozyme, thereby making its catalytic performance ineffective. The concentration of glyphosate exhibited a linear range spanning from 2 to 400 μmol L−1, and the limit of detection was 0.67 μmol L−1 (S/N = 3). The colorimetric sensing approach employing AgNPs/Cu-TCPP nanozyme exhibits remarkable selectivity and reproducibility, enabling the detection of real samples with recovery rates of 98.3%–103.5%, indicating its potential applicability in safeguarding water and food quality.

Voters’ influence on local tax policy

In a well-functioning democracy, citizens can influence public policy through voting. By voting prospectively, voters may aim to select politicians that make policies in line with their preferences, and, by voting retrospectively, they may reward or punish politicians for their performance. To what extent voters actually influence policy is unclear, especially in local government, where many impediments to policy responsiveness may exist. Moreover, voters may realize that their influence on public policy is negligible and vote expressively instead of instrumentally. We investigate a key area in public policy, tax policy, using panel data on municipalities in the Netherlands in the period 1998–2021. We find that changes in the political color of the municipal council on average do not lead to changes in tax levels or tax distribution. However, incumbents that lower taxes fare better at the polls than incumbents that moderately increase taxes. Interestingly, strong tax increases do not lead to more severe electoral punishment, and punishment does not seem to differ between left-wing and right-wing incumbents. Our results suggest that expressive voting plays an important role. People may vote left-wing and express their identity as charitable persons, and then punish incumbents who actually raise taxes.

Effects of gamma radiation on cyclic olefin copolymers with varied norbornene content: Impacts on structure and properties at sterilization doses

Cyclic olefin copolymer (COC) is a transparent amorphous plastic known for its chemically inertness, biocompatibility, low density, and easy processability. These qualities have led to its widespread adoption in various cutting-edge applications, including the medical, packaging, optical and microelectronics. Radiation sterilization, utilizing high-energy irradiation, is a method for achieving highly effective sterilization of medical products. However, this process can induce changes in the color and properties of the COC materials. In order to comprehend the effects of ionizing radiation on COC, it is crucial to investigate the underlying reaction mechanisms. In this work, the effects of γ-ray irradiation on COC with different norbornene contents were examined. The finding revealed that tertiary alkyl radical content and the degree of oxidative degradation increased with an increase in norbornene content. Furthermore, the macroscopic properties experienced notable shifts, including decreased thermal stability, lower glass transition temperature and the change in color from colorless and transparent to yellow-green. Analysis of the melt index indicated a dominance of cross-linking phenomena with increased absorbed dose for COC with a norbornene content of 35%, while the melt flow rate steadily accelerated with the increase of absorbed dose for COC with norbornene content of 46%, 52% and 57%, leading to a predominant cracking behavior. The variation in tensile properties of the four COCs before and after irradiation were minimal, not exceeding 3%. Overall, this investigation sheds light on the intricate effects of ionizing radiation on COC and highlights the importance of understanding these mechanisms for practical applications.

Novel ratiometric fluorescent probe with large Stokes shift for selective sensing and imaging of Zn2+ in live cell

A novel ratiometric fluorescent probe, namely 5-[(3-dicyanoylidene −5.5-dimethyl) cyclohexenyl-1-ethenyl] salicylaldehyde-3′-hydroxybenzohydrazone (DCSH) is presented for the selective sensing of Zn2+ ion in acetonitrile/water (2/3, pH 7.4) solution. Introducing Zn2+ ions notably caused the peak emission of DCSH to shift from 560 nm to 646 nm, accompanied with a significant enhancement of its intensity. A vivid change in fluorescence color from yellow to red facilitated the immediate identification of Zn2+ ions by visual observation. DCSH exhibits substantial Stokes shifts (110 and 196 nm), rapid detection capability (within 10 s) and high sensitivity to Zn2+ ions, achieving a limit of detection of 31.2 nM. The response mechanism is supposed to involve the block of C = N bond isomerization and excited state intramolecular proton transfer (ESIPT) along with the enhancement of fluorescence through chelation (CHEF) effect. DCSH was effectively utilized for ratiometric fluorescence imaging to monitor exogenous Zn2+ concentrations in HeLa cells. Significantly, DCSH is capable of monitoring elevated levels of Zn2+ ion during apoptosis induced by L-Buthionine sulfoximine (BSO).

Patterned Photonic Actuators with Dynamic Shape‐Morphing and Color‐Changing Capabilities Fabricated by Athermal Embossing Technology

AbstractStimuli‐responsive patterned photonic actuators, characterized by their patterned nano/microscale structures and capacity to demonstrate synergistic color changes and shape morphing in response to external stimuli, have attracted intense scientific attention. However, traditional patterned photonic actuator systems still face limitations such as cumbersome and time‐consuming preparation processes and small‐scale deformations. Herein, we introduce a facile approach involving an athermal embossing technique to rapidly fabricate patterned photonic actuators based on near‐infrared (NIR) light‐responsive liquid crystal elastomers. The resulting patterned photonic actuators demonstrate remarkable features, including brilliant angle‐dependent structural color, complex three‐dimensional actuation, and good color durability under NIR light stimulation. As illustrative demonstrations of the proof‐of‐concept, we fabricate two light‐fuelled patterned photonic soft actuators: a butterfly‐inspired actuator that can produce wing‐flapping dynamic changes in structural color, and an origami crane‐shaped actuator with shape memory, structural color information storage, and dynamic display properties. This strategy provides distinct insights into the design and fabrication of various patterned photonic soft robotic devices and intelligent actuators.