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V. Pratap, C. J. Hennigan, B. Stieger et al.

<p>Aerosol acidity has importance for the chemical and physical properties of atmospheric aerosol particles and for many processes that affect their transformation and fate. Here, we characterize trends in PM<span class="inline-formula">₁₀</span> pH and its controlling factors during the period of 2010–2019 at the Melpitz research station in eastern Germany, a continental background site in Central Europe. Aerosol liquid water content associated with inorganic species decreased by 3.4 <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">µ</mi><mi mathvariant="normal">g</mi><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">3</mn></mrow></msup><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">a</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="53pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="f80f1623485927b12994377af17bfc41"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-25-8871-2025-ie00001.svg" width="53pt" height="15pt" src="acp-25-8871-2025-ie00001.png"/></svg:svg></span></span>, corresponding to a 50 % decrease during the analysed time period, in response to decreasing sulfate and nitrate. Aerosol pH exhibited an increase of 0.06 units per year, a trend that was distinct from other regions. The factors controlling aerosol pH varied by season. Temperature, the most important factor driving pH variability overall, was most important in summer (responsible for 51 % of pH variability) and less important during spring and fall (22 % and 27 %, respectively). <span class="inline-formula">NH₃</span>, the second-most important factor contributing to pH variability overall (29 %), was most important during winter (38 %) and far less important during summer (15 %). Aerosol chemistry in Melpitz is influenced by the high buffering capacity contributed by <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn><mo>+</mo></msubsup><mo>/</mo><msub><mi mathvariant="normal">NH</mi><mn mathvariant="normal">3</mn></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="50pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="727a976ac89bd2aea53a86b29d185a83"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-25-8871-2025-ie00002.svg" width="50pt" height="15pt" src="acp-25-8871-2025-ie00002.png"/></svg:svg></span></span> and, to a lesser degree, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">NO</mi><mn mathvariant="normal">3</mn><mo>-</mo></msubsup><mo>/</mo><msub><mi mathvariant="normal">HNO</mi><mn mathvariant="normal">3</mn></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="59pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="a0e446ae319fab66de56c83999903a56"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-25-8871-2025-ie00003.svg" width="59pt" height="16pt" src="acp-25-8871-2025-ie00003.png"/></svg:svg></span></span>. Thermodynamic analysis of the aerosol system shows that secondary inorganic aerosol formation is most frequently <span class="inline-formula">HNO₃</span>-limited, suggesting that factors that control <span class="inline-formula">NO_<i>x</i></span> would be more effective than <span class="inline-formula">NH₃</span> controls in reducing PM mass concentrations. However, the non-linear response of gas-phase <span class="inline-formula">HNO₃</span> and aerosol <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M10" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">NO</mi><mn mathvariant="normal">3</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="25pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="dd23f13eb24280cbe650be4567ce8571"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-25-8871-2025-ie00004.svg" width="25pt" height="16pt" src="acp-25-8871-2025-ie00004.png"/></svg:svg></span></span> to <span class="inline-formula">NO_<i>x</i></span> emissions in the region, likely due to VOC controls on oxidant formation and subsequent impacts on <span class="inline-formula">NO_<i>x</i></span> conversion to <span class="inline-formula">HNO₃</span>, highlights the challenge associated with the PM reductions needed to attain new air quality standards in this region.</p>

Fujiang Huang, Ruiyuan Zhang, Zhengyu Lv et al.

An accurate assessment of fish stocks is crucial for maintaining the health and stability of aquatic ecosystems. To understand the characteristics of fish diversity in the Qingshui River, this study utilized high-throughput sequencing data obtained through environmental DNA macrobarcoding technology (eDNA). The research explored differences in fish diversity and community characteristics in the Qingshui River by analyzing fish community structure, α diversity, β diversity, and the redundancy of environmental factors. This analysis aims to provide data support for water ecological monitoring and management. The results were as follows: (1) A total of 91 species of fishes from 18 families and seven orders were detected in the eDNA survey, and the dominant species was Cypriniformes, accounting for 72.5%. (2) There were significant differences in α diversity analysis in the Qingshui River (<i>p</i> < 0.05). (3) The fish community structure was similar in β diversity analysis. (4) In the redundancy analysis of environmental factors, pH, DO, TN, TP, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msubsup><mrow><mi mathvariant="normal">N</mi><mi mathvariant="normal">O</mi></mrow><mn>2</mn><mo>−</mo></msubsup></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msubsup><mrow><mi mathvariant="normal">M</mi><mi mathvariant="normal">n</mi><mi mathvariant="normal">O</mi></mrow><mn>4</mn><mo>−</mo></msubsup></semantics></math></inline-formula> have the greatest impact on the Qingshui River Basin. eDNA technology has the advantages of high efficiency and low harm and can be used for water ecological monitoring and management. It provides a scientific basis for fish protection and a valuable reference for fish monitoring in the future.

Eduardo R. Garrido-Ortiz, Jocksan I. Morales-Camacho

The search for sustainable and health-promoting food sources has increased interest in edible insects, which are rich in proteins and bioactive compounds with potential nutraceutical applications. In this study, we evaluated the bioactive properties of protein hydrolysates derived from <i>Aegiale hesperiaris</i> (maguey white worm, WW) and <i>Comadia redtenbacheri</i> (maguey red worm, RW), two culturally and economically significant insect species in Mexico. Hydrolysates were obtained via enzymatic treatments: either single hydrolysis with pepsin (PH) or sequential hydrolysis with pepsin followed by trypsin (PTH). The PTH hydrolysates exhibited strong antioxidant activity, with 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical inhibition above 90% and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity between 75–85%. Additionally, they showed significant angiotensin-converting enzyme (ACE) inhibitory activity, reaching IC₅₀ values of 0.35 and 0.017 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>g/mL for WWPH and RWPH, respectively—the latter outperforming the commercial drug Enalapril (IC₅₀ = 0.11 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>g/mL). SDS-PAGE analysis revealed low molecular weight peptides (<10 kDa), especially between 5–9 kDa, associated with enhanced bioactivity. Peptides from RW also showed low Hill coefficients, suggesting a gradual and sustained interaction with ACE. These findings support the use of insect-derived hydrolysates as promising multifunctional ingredients for the development of functional foods targeting cardiovascular health.

Rodolphe Kinghat, Abderrahim Khatyr, Michael Knorr et al.

The thioether-functionalized 2-azabutadienes (ArS)₂C=C(H)-N=CPh₂ (<b>L1</b> Ar = Ph, <b>L2</b> Ar = <i>p</i>-Tol) ligate to [Mn(CO)₅Br] to form the octahedral five-membered <i>S</i>, <i>N</i>-chelate complexes <i>fac</i>-[MnBr(CO)₃{(ArS)₂C=C(H)-N=CPh₂] (<b>1</b> Ar = Ph; <b>2</b> Ar = <i>p</i>-Tol), whose crystal structures have been solved by X-ray diffraction. Complex <b>1</b> crystallizes in the non-centrosymmetric orthorhombic space group <i>P</i>2₁2₁2₁, whereas <b>2</b> crystallizes in the triclinic space group <i>P</i><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mover accent="false"><mrow><mn>1</mn></mrow><mo>¯</mo></mover></mrow></semantics></math></inline-formula>. The secondary interactions occurring in the packing have also been assessed by an Atoms in Molecules (AIM) topological analysis.

Miaomiao Ye, Jingqiu Wu, Qiuyuan Weng et al.

The utilization of carbon dioxide (CO₂) offers an effective approach for alleviating the carbon-reduction pressures associated with fossil energy consumption. However, studies on the use of CO₂ as an auxiliary agent in water treatment to enhance the removal of emerging contaminants are limited. In this study, the photodegradation of ciprofloxacin (CIP) was investigated using ultraviolet (UV) irradiation combined with CO₂ dosing (UV/CO₂). The results demonstrated that the UV/CO₂ system effectively degraded CIP, with CO₂ concentration and solution pH exerting a critical influence. Inorganic anions and metal cations had negligible effects on CIP degradation efficiency, whereas natural organic matter (NOM) had a pronounced inhibitory effect. Mechanistic analysis revealed that superoxide radicals (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>·</mo><msubsup><mi mathvariant="normal">O</mi><mn>2</mn><mo>-</mo></msubsup></mrow></semantics></math></inline-formula>) and carbonate radicals (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mi>CO</mi></mrow><mn>3</mn><mrow><mrow><mo>•</mo><mo>-</mo></mrow></mrow></msubsup></mrow></semantics></math></inline-formula>) were the primary oxidizing species, whereas the excited triplet state of CIP (³CIP*) and singlet oxygen played crucial roles in initiating radical generation. LC–MS analysis and density functional theory calculations indicated that the main degradation routes involved defluorination, decarboxylation, and epoxidation of the piperazine ring. Toxicity assessment indicated that the transformation products generated by UV/CO₂ were less toxic than the parent compound. Furthermore, the UV/CO₂ process demonstrated high energy efficiency, with a low electrical energy per order (EEO) value of 0.4193 kWh·m⁻³·order⁻¹. These findings suggest that the UV/CO₂ system is a promising alternative for the treatment of photosensitive organic pollutants and provides a beneficial pathway for CO₂ utilization.

Soma Bartha, András Kerekes, Zoltán Kovács et al.

Renxian Li, Huan Tang, Mingyu Zhang et al.

The selective control and manipulation of nanoparticles require developing and researching new methods for designing optical tweeters, mainly based on a photonic hooks (PHs) effect. This paper first proposes a tunable PH in which a structured beam illuminates an anisotropic cutting liquid crystal microcylinder based on the Finite-DifferenceTime-Domain (FDTD) method. The PHs generated by plane wave, Gaussian, and Bessel beam are analyzed and compared. The impact of beams and LC particle parameters on the PHs are discussed. Where the influence of the extraordinary refractive index (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>n</mi><mi mathvariant="normal">e</mi></msub></semantics></math></inline-formula>) on PHs is emphasized. Our results reveal that introducing birefringence can change the bending direction of PH. Besides, the maximum intensity of the PHs increases as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>n</mi><mi>e</mi></msub></semantics></math></inline-formula> increases regardless of the beam type. The PH generated by a plane wave has a higher maximum intensity and smaller FWHM than that generated by the Gaussian and Bessel beams. The smallest FWHM and maximum intensity of the PHs generated by the Gaussian falls between that generated by the plane wave and the Bessel beam. The PH generated by a Bessel beam has the minor maximum intensity and the largest FWHM. Still, it exceeds the diffraction limit and exhibits bending twice due to its self-recovery property. This paper provides a new way to modulate PH. This work offers novel theoretical models and the degree of freedom for the design of PHs, which is beneficial for the selective manipulation of nanoparticles. It has promising applications in Mesotronics and biomedicine.

A. A. Adekanmbi, A. A. Adekanmbi, L. Dale et al.

<p>Predictions concerning the feedback of soil heterotrophic respiration to a warming climate often do not differentiate between the extracellular and intracellular steps involved in soil organic matter decomposition. This study examined the temperature sensitivities of intracellular metabolic processes and extracellular soil enzyme activities and how they are influenced by previous temperatures. We pre-incubated soils at 5, 15, or 26 <span class="inline-formula">^∘</span>C to acclimatize the microbial communities to different thermal regimes for 60 d before measuring potential activities of <span class="inline-formula"><i>β</i></span>-glucosidase and chitinase (extracellular enzymes), glucose-induced respiration (intracellular metabolic processes), and basal respiration at a range of assay temperatures (5, 15, 26, 37, and 45 <span class="inline-formula">^∘</span>C). A higher pre-incubation temperature decreased the soil pH and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">C</mi><mo>/</mo><mi mathvariant="normal">N</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="24pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="a1fd226718b6fd2378e4d645ff1b8807"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-2207-2023-ie00001.svg" width="24pt" height="14pt" src="bg-20-2207-2023-ie00001.png"/></svg:svg></span></span> ratio and decreased <span class="inline-formula"><i>β</i></span>-glucosidase potential activity and respiration but not chitinase potential activity. It is likely that this legacy effect on <span class="inline-formula"><i>β</i></span>-glucosidase and respiration is an indirect effect of substrate depletion rather than physiological acclimatation or genetic adaptation. Pre-incubation temperature effects on temperature sensitivity were subtle and restricted to extracellular activities, perhaps because of the short (60 d) duration of the pre-incubation at temperatures that were below the initial optimum (<span class="inline-formula">∼</span> 30 <span class="inline-formula">^∘</span>C) for the mesophilic soil community. However, we found that the intracellular and extracellular steps differ in their temperature sensitivity, and this observation differs depending on the range of temperature used for <span class="inline-formula"><i>Q</i>₁₀</span> estimates of temperature sensitivity. Between 5 and 15 <span class="inline-formula">^∘</span>C intracellular and extracellular processes show equal temperature sensitivity, but between 15 and 26 <span class="inline-formula">^∘</span>C intracellular metabolic processes were more temperature sensitive than extracellular enzyme activity, and between 26 and 37 <span class="inline-formula">^∘</span>C extracellular enzyme activity was more temperature sensitive than intracellular metabolic processes. This result implies that depolymerization of higher molecular weight carbon is more sensitive to temperature changes at higher temperatures (e.g. higher temperatures on extremely warm days), but the respiration of the generated monomers is more sensitive to temperature changes at moderate temperatures (e.g. mean daily maximum soil temperature). However, studies using multiple soil types and a greater range of pre-incubation temperatures are required to generalize our results. Nevertheless, since climate change predictions currently indicate that there will be a greater frequency and severity of hot summers and heatwaves, it is possible that global warming may reduce the importance of extracellular depolymerization relative to intracellular metabolic processes as the rate-limiting step of soil organic matter mineralization. We conclude that extracellular and intracellular steps are not equally sensitive to changes in soil temperature and that the previous temperature a soil is exposed to may influence the potential activity, but not temperature sensitivity, of extracellular and intracellular processes.</p>

Slimane Laref, Fouzi Harrou, Bin Wang et al.

Favipiravir (FP) and Ebselen (EB) belong to a broad range of antiviral drugs that have shown active potential as medications against many viruses. Employing molecular dynamics simulations and machine learning (ML) combined with van der Waals density functional theory, we have uncovered the binding characteristics of these two antiviral drugs on a phosphorene nanocarrier. Herein, by using four different machine learning models (i.e., Bagged Trees, Gaussian Process Regression (GPR), Support Vector Regression (SVR), and Regression Trees (RT)), the Hamiltonian and the interaction energy of antiviral molecules in a phosphorene monolayer are trained in an appropriate way. However, training efficient and accurate models for approximating the density functional theory (DFT) is the final step in using ML to aid in the design of new drugs. To improve the prediction accuracy, the Bayesian optimization approach has been employed to optimize the GPR, SVR, RT, and BT models. Results revealed that the GPR model obtained superior prediction performance with an <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>R</mi><mn>2</mn></msup></semantics></math></inline-formula> of 0.9649, indicating that it can explain 96.49% of the data’s variability. Then, by means of DFT calculations, we examine the interaction characteristics and thermodynamic properties in a vacuum and a continuum solvent interface. These results illustrate that the hybrid drug is an enabled, functionalized 2D complex with vigorous thermostability. The change in Gibbs free energy at different surface charges and temperatures implies that the FP and EB molecules are allowed to adsorb from the gas phase onto the 2D monolayer at different pH conditions and high temperatures. The results reveal a valuable antiviral drug therapy loaded by 2D biomaterials that may possibly open a new way of auto-treating different diseases, such as SARS-CoV, in primary terms.

B. Zhao, A. Dou, Z. Zhang et al.

<p>Reactive iron (Fe) oxides are vital for long-term soil or sediment organic carbon (SOC) storage. However, the patterns and drivers of Fe-associated organic carbon (Fe-OC) over global geographic scales under various ecosystem types remain controversial. Here, we provided a systematic assessment of the distribution patterns and determinants of Fe-OC content and its contribution to SOC (<span class="inline-formula"><i>f</i></span>Fe-OC) by assembling a global dataset comprising 862 observations from 325 sites in distinct ecosystems. We found that Fe-OC content across global ecosystems ranged from 0 to 83.3 g kg<span class="inline-formula">⁻¹</span> (<span class="inline-formula"><i>f</i></span>Fe-OC ranged from 0 % to 82.4 %), reflecting the high variability of the Fe-OC pool. Fe-OC contents varied with ecosystem type being greater in wetlands with a high molar ratio of Fe-OC <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="57ee8123d9c9aefcf23d9c7f6463c158"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-4761-2023-ie00001.svg" width="8pt" height="14pt" src="bg-20-4761-2023-ie00001.png"/></svg:svg></span></span> dithionite-extractable Fe (Fe<span class="inline-formula">_d)</span> compared with marine and terrestrial ecosystems. Furthermore, <span class="inline-formula"><i>f</i></span>Fe-OC in wetlands was significantly lower than that in other ecosystems due to rich organic carbon (OC). In contrast with climate variables and soil pH, the random forest modeling and multivariate analysis showed that the Fe-OC <span class="inline-formula">:</span> Fe<span class="inline-formula">_d</span> and SOC were the predominant predictors of Fe-OC content and <span class="inline-formula"><i>f</i></span>Fe-OC in wetlands and terrestrial ecosystems, whereas Fe<span class="inline-formula">_d</span> content was a primary driver in marine ecosystems. Based on upper estimates of global SOC storage in various ecosystem types, we further estimated that 83.84 <span class="inline-formula">±</span> 3.8, 172.45 <span class="inline-formula">±</span> 8.74, and 24.48 <span class="inline-formula">±</span> 0.87 Pg of SOC were preserved by association with Fe oxides in wetland, terrestrial, and marine ecosystems, respectively. Taken together, our findings highlighted the importance of reactive Fe oxides in global SOC preservation, and their controlling factors were ecosystem specific.</p>

M. Stepanova, M. Novak, B. Cejkova et al.

<p>Availability of reactive nitrogen (N<span class="inline-formula">_r</span>) is a key control on carbon (C) sequestration in wetlands. To complement the metabolic demands of <i>Sphagnum</i> in pristine rain-fed bogs, diazotrophs supply additional N<span class="inline-formula">_r</span> via biological nitrogen fixation (BNF). As breaking the triple bond of atmospheric N<span class="inline-formula">₂</span> is energy-intensive, it is reasonable to assume that increasing inputs of pollutant N<span class="inline-formula">_r</span> will lead to BNF downregulation. However, recent studies have also documented measurable BNF rates in <i>Sphagnum</i>-dominated bogs in polluted regions, indicating the adaptation of N<span class="inline-formula">₂</span> fixers to changing N deposition. Our aim was to quantify BNF in high-elevation peatlands located in industrialized central Europe. A <span class="inline-formula">¹⁵</span>N<span class="inline-formula">₂</span>-tracer experiment was combined with a natural-abundance N-isotope study at three <i>Sphagnum</i>-dominated peat bogs in the northern Czech Republic in an attempt to assess the roles of individual BNF drivers. High short-term BNF rates (8.2 <span class="inline-formula">±</span> 4.6 g N m<span class="inline-formula">²</span> d<span class="inline-formula">⁻¹</span>) were observed at Malé mechové jezírko, which receives <span class="inline-formula">∼</span> 17 kg N<span class="inline-formula">_r</span> ha<span class="inline-formula">⁻¹</span> yr<span class="inline-formula">⁻¹</span>. The remaining two peat bogs, whose recent atmospheric N<span class="inline-formula">_r</span> inputs differed from Malé mechové jezírko by only 1–2 kg ha<span class="inline-formula">⁻¹</span> yr<span class="inline-formula">⁻¹</span> (Uhlír̆ská and Brumiště), showed zero BNF. The following parameters were investigated to elucidate the BNF difference: the NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M22" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="51ca01690260423140b5b0de9583232a"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00001.svg" width="8pt" height="15pt" src="soil-9-623-2023-ie00001.png"/></svg:svg></span></span>-N <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M23" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="265e2a7d42d09da6c1e252e5649f9787"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00002.svg" width="8pt" height="14pt" src="soil-9-623-2023-ie00002.png"/></svg:svg></span></span> NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M24" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">3</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="d615913ec88b34ee0c05b0f0374db64d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00003.svg" width="9pt" height="16pt" src="soil-9-623-2023-ie00003.png"/></svg:svg></span></span>-N ratio, temperature, wetness, <i>Sphagnum</i> species, organic-N availability, possible P limitation, possible molybdenum (Mo) limitation, SO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M25" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="820c2a883eb6831c3f3dfbf9fe5018ac"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00004.svg" width="13pt" height="17pt" src="soil-9-623-2023-ie00004.png"/></svg:svg></span></span> deposition, and pH. At Malé mechové jezírko and Uhlír̆ská, the same moss species (<i>S. girgensohnii</i>) was used for the <span class="inline-formula">¹⁵</span>N<span class="inline-formula">₂</span> experiment; therefore, the host identity could not explain the difference in BNF at these sites. Temperature and moisture were also identical in all incubations and could not explain the between-site differences in BNF. The N : P stoichiometry in peat and bog water indicated that Brumiště may have lacked BNF due to P limitation, whereas non-detectable BNF at Uhlír̆ská may have been related to the 70-fold higher SO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M28" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="af7843922aebc745671236cec92f9569"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00005.svg" width="13pt" height="17pt" src="soil-9-623-2023-ie00005.png"/></svg:svg></span></span> concentration in bog water. Across the sites, the mean natural-abundance <span class="inline-formula"><i>δ</i>¹⁵</span>N values increased in the following order: atmospheric deposition (<span class="inline-formula">−</span>5.3 <span class="inline-formula">±</span> 0.3 ‰) <span class="inline-formula"><i>&lt;</i></span> <i>Sphagnum</i> (<span class="inline-formula">−</span>4.3 <span class="inline-formula">±</span> 0.1 ‰) <span class="inline-formula"><i>&lt;</i></span> bog water (<span class="inline-formula">−</span>3.9 <span class="inline-formula">±</span> 0.4 ‰) <span class="inline-formula"><i>&lt;</i></span> atmospheric N<span class="inline-formula">₂</span> (0.0 ‰). Only at Brumiště was N in <i>Sphagnum</i> significantly isotopically heavier than in atmospheric deposition, possibly indicating a longer-term BNF effect. Collectively, our data highlight spatial heterogeneity in BNF rates under high N<span class="inline-formula">_r</span> inputs as well as the importance of environmental parameters other than atmospheric N<span class="inline-formula">_r</span> pollution in regulating BNF.</p>

Mirat Karibayev, Sandugash Kalybekkyzy, Yanwei Wang et al.

Anion Exchange Membrane (AEM) fuel cells have attracted growing interest, due to their encouraging advantages, including high power density and relatively low cost. AEM is a polymer matrix, which conducts hydroxide (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>OH</mi><mo>−</mo></msup></semantics></math></inline-formula>) ions, prevents physical contact of electrodes, and has positively charged head groups (mainly quaternary ammonium (QA) groups), covalently bound to the polymer backbone. The chemical instability of the quaternary ammonium (QA)-based head groups, at alkaline pH and elevated temperature, is a significant threshold in AEMFC technology. This review work aims to introduce recent studies on the chemical stability of various QA-based head groups and transportation of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>OH</mi><mo>−</mo></msup></semantics></math></inline-formula> ions in AEMFC, via modeling and simulation techniques, at different scales. It starts by introducing the fundamental theories behind AEM-based fuel-cell technology. In the main body of this review, we present selected computational studies that deal with the effects of various parameters on AEMs, via a variety of multi-length and multi-time-scale modeling and simulation methods. Such methods include electronic structure calculations via the quantum Density Functional Theory (DFT), ab initio, classical all-atom Molecular Dynamics (MD) simulations, and coarse-grained MD simulations. The explored processing and structural parameters include temperature, hydration levels, several QA-based head groups, various types of QA-based head groups and backbones, etc. Nowadays, many methods and software packages for molecular and materials modeling are available. Applications of such methods may help to understand the transportation mechanisms of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>OH</mi><mo>−</mo></msup></semantics></math></inline-formula> ions, the chemical stability of functional head groups, and many other relevant properties, leading to a performance-based molecular and structure design as well as, ultimately, improved AEM-based fuel cell performances. This contribution aims to introduce those molecular modeling methods and their recent applications to the AEM-based fuel cells research community.

M. Ward, T. L. Kindinger, H. K. Hirsh et al.

<p>Seagrass meadow metabolism has been measured for decades to gain insight into ecosystem energy, biomass production, food web dynamics, and, more recently, to inform its potential in ameliorating ocean acidification (OA). This extensive body of literature can be used to infer trends and drivers of seagrass meadow metabolism. Here, we synthesize the results from 56 studies reporting in situ rates of seagrass gross primary productivity, respiration, and/or net community productivity to highlight spatial and temporal variability in oxygen (<span class="inline-formula">O₂</span>) fluxes. We illustrate that daytime net community production (NCP) is positive overall and similar across seasons and geographies. Full-day NCP rates, which illustrate the potential cumulative effect of seagrass beds on seawater biogeochemistry integrated over day and night, were also positive overall but were higher in summer months in both tropical and temperate ecosystems. Although our analyses suggest seagrass meadows are generally autotrophic, the effects on seawater oxygen are relatively small in magnitude. We also find positive correlations between gross primary production and temperature, although this effect may vary between temperate and tropical geographies and may change under future climate scenarios if seagrasses approach thermal tolerance thresholds. In addition, we illustrate that periods when full-day NCP is highest could be associated with lower nighttime <span class="inline-formula">O₂</span> and increased diurnal variability in seawater <span class="inline-formula">O₂</span>. These results can serve as first-order estimates of when and where OA amelioration by seagrasses may be likely. However, improved understanding of variations in <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mtext>NCP</mtext><mtext>DIC</mtext></msub><mo>:</mo><msub><mtext>NCP</mtext><mrow class="chem"><msub><mi mathvariant="normal">O</mi><mn mathvariant="normal">2</mn></msub></mrow></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="80pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="ef2c7449bae9f8d8071bf1548ec2a899"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-19-689-2022-ie00001.svg" width="80pt" height="15pt" src="bg-19-689-2022-ie00001.png"/></svg:svg></span></span> ratios and increased work directly measuring metabolically driven alterations in seawater pH will further inform the potential for seagrass meadows to serve in this context.</p>

Kwanele Sigcau, Ignatius Leopoldus van Rooyen, Zian Hoek et al.

Phytoremediation technologies are employed worldwide to remove nutrient pollutants from agricultural and industrial wastewater. Unlike in algae-based nutrient removal, control methodologies for plant-based remediation have not been standardized. Control systems that guarantee consistently low outlet concentrations of nitrogen and phosphorous often use expensive analytical instruments and are therefore rarely viable. In this study, pH measurement was used as the sole input to control the nitrate outlet concentration in a continuously operated <i>Lemna minor</i> (lesser duckweed) phytoremediation tank. When grown in 20 L batches of modified Hoagland’s solution, it was found that a constant ratio exists between the amount of nitrate removed and the amount of acid dosed (required for pH control), which was equal to 1.25 mol N·(mol H⁺)<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>. The nitrate uptake rates were determined by standard spetrophotometric method. At critically low nitrate concentrations, this ratio reduced slightly to 1.08 mol N·(mol H⁺)<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>. Assuming a constant nitrogen content, the biomass growth rate could be predicted based on the acid dosing rate. A proportional-integral controller was used to maintain pH on 6.5 in a semi-continuously operated tank covered by <i>L. minor</i>. A nitrogen control strategy was developed which exploited this relationship between nitrate uptake and dosing and successfully removed upwards of 80% of the fed nitrogen from synthetic wastewater while a constant biomass layer was maintained. This study presents a clear illustration of how advanced chemical engineering control principles can be applied in phytoremediation processes.

J. G. M. Crumpton-Banks, T. Tanner, I. Hernández Almeida et al.

<p>Recent advances in geochemical techniques mean that several robust proxies now exist to determine the past carbonate chemistry of the oceans. Foraminiferal <span class="inline-formula"><i>δ</i>¹¹</span>B and alkenone carbon isotopes allow us to reconstruct sea-surface pH and <span class="inline-formula"><i>p</i></span>CO<span class="inline-formula">₂</span>, respectively, and the ability to apply both proxies to the same sediment sample would give strongly paired datasets and reduce sample waste. However, no studies to date have examined whether the solvents and extraction techniques used to prepare alkenones for analysis also impact the geochemistry of foraminifera within those sediments. Here we examine six species pairs of planktic foraminifera, with half being taken from non-treated sediments and half being taken from sediments where alkenones have been extracted. We look for visual signs of contrasting preservation and compare analyses of <span class="inline-formula"><i>δ</i>¹⁸</span>O, <span class="inline-formula"><i>δ</i>¹³</span>C, <span class="inline-formula"><i>δ</i>¹¹</span>B and trace elements (Li, B, Na, Mn, Mg, Sr and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mrow class="chem"><mi mathvariant="normal">U</mi><mo>/</mo><mi mathvariant="normal">Ca</mi></mrow></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="30pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="57892143d10ff0098732657af533175c"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-19-5633-2022-ie00001.svg" width="30pt" height="14pt" src="bg-19-5633-2022-ie00001.png"/></svg:svg></span></span>). We find no consistent geochemical offset between the treatments and excellent agreement in <span class="inline-formula"><i>δ</i>¹¹</span>B measurements between them. Our results show that boron isotope reconstructions of pH in foraminifera from alkenone-extracted sediments can be applied with confidence.</p>

A. Suto

In this third paper of a series that started with arXiv:2106.10032 [math-ph] and continued with arXiv:2108.02659 [math-ph] we show that in $d\geq 3$ dimensions at low temperatures or high densities bosons interacting via pair potentials that are both positive and positive type form permutation cycles whose length diverges proportionally with the number of particles. Based on the second-cited paper, this implies Bose-Einstein condensation.

Samir Popovici

T. V. Nuland

This paper shows how to construct classical and quantum field C*-algebras modeling a $$U(1)^n$$ U ( 1 ) n -gauge theory in any dimension using a novel approach to lattice gauge theory, while simultaneously constructing a strict deformation quantization between the respective field algebras. The construction starts with quantization maps defined on operator systems (instead of C*-algebras) associated with the lattices, in a way that quantization commutes with all lattice refinements, therefore giving rise to a quantization map on the continuum (meaning ultraviolet and infrared) limit. Although working with operator systems at the finite level, in the continuum limit we obtain genuine C*-algebras. We also prove that the C*-algebras (classical and quantum) are invariant under time evolutions related to the electric part of abelian Yang–Mills. Our classical and quantum systems at the finite level are essentially the ones of van Nuland and Stienstra (Classical and quantized resolvent algebras for the cylinder, 2020. arXiv:2003.13492 [math-ph]), which admit completely general dynamics, and we briefly discuss ways to extend this powerful result to the continuum limit. We also briefly discuss reduction, and how the current setup should be generalized to the non-abelian case.

A. Suto

Fourier expansion of the integrand in the path integral formula for the partition function of quantum systems leads to a deterministic expression which, though still quite complex, is easier to process than the original functional integral. It therefore can give access to problems that eluded solution so far. Here we derive the formula; applications to the problem of Bose-Einstein condensation are presented in the papers arXiv:2108.02659 [math-ph] and arXiv:2208.08931 [math-ph].

Pablo García-Molina, José Luis Munoz-Munoz, Joaquin A. Ortuño et al.

With the purpose to obtain the more useful tyrosinase assay for the monophenolase activity of tyrosinase between the spectrofluorometric and spectrophotometric continuous assays, simulated assays were made by means of numerical integration of the equations that characterize the mechanism of monophenolase activity. These assays showed that the rate of disappearance of monophenol (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi mathvariant="normal">V</mi><mrow><mi>ss</mi></mrow><mrow><mi mathvariant="normal">M</mi><mo>,</mo><mi mathvariant="normal">M</mi></mrow></msubsup></mrow></semantics></math></inline-formula>) is equal to the rate of accumulation of dopachrome (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi mathvariant="normal">V</mi><mrow><mi>ss</mi></mrow><mrow><mi mathvariant="normal">M</mi><mo>,</mo><mi>DC</mi></mrow></msubsup></mrow></semantics></math></inline-formula>) or to the rate of accumulation of its oxidized adduct, originated by the nucleophilic attack on <i>o</i>-quinone by a nucleophile such as 3-methyl-2-benzothiazolinone (MBTH), (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi mathvariant="normal">V</mi><mrow><mi>ss</mi></mrow><mrow><mi mathvariant="normal">M</mi><mo>,</mo><mrow><mtext> </mtext><mi mathvariant="normal">A</mi></mrow><mo>−</mo><mi>ox</mi></mrow></msubsup></mrow></semantics></math></inline-formula>), despite the existence of coupled reactions. It is shown that the spectrophotometric methods that use MBTH are more useful, as they do not have the restrictions of the L-tyrosine disappearance measurement method, of working at pH = 8 and not having a linear response from 100 μM of L-tyrosine. It is possible to obtain low LOD^M (limit of detection of the monophenolase activity) values with spectrophotometric methods. The spectrofluorimetric methods had a lower LOD^M than spectrophotometric methods. In the case of 4-hydroxyphenil-propionic acid, the LOD^M obtained by us was 0.25 U/mL. Considering the relative sensitivities of 4-hydroxyanisole, compared with 4-hydroxyphenil-propionic acid, LOD^M values like those obtained by fluorescent methods would be expected.