bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased response to cadmium and Bacillus thuringiensis maize toxicity in the snail Helix aspersa infected by the nematode Phasmarhabditis hermaphrodita
Authors: Kramarz Paulina E. , de Vaufleury Annette , Zygmunt Piotr M. S. , Verdun Cyrille
Published: December 2006

To determine the effect of nematode infection on the response of snails to selected toxins, we infected Helix aspersa with 0-, 0.25-, 1-, or 4-fold the recommended field dose of a commercial nematode application for agricultural use. In the first experiment, the snails also were exposed to cadmium via food and soil at concentrations of 0, 30, 60, 120, or 240 mg/kg in a fullfactorial design. In the second experiment, snails were infected with nematodes and also fed either Bt (expressing Bacillus thuringiensis toxin) maize or non-Bt maize. The snails were weighed at the beginning and end (after four weeks) of the experiments, and mortality was checked daily. Neither exposure of snails to nematodes nor exposure of snails to cadmium or Bt toxin affected the survival rates of snails. The number of dead snails was highest for combinations of nematode treatments with cadmium concentrations of 120 and 240 mg/kg. In both experiments (Bt and cadmium), the growth rate decreased with increasing nematode dose. The Bt maize was not harmful to the snails in the absence of nematodes, but infected snails grew faster when fed non-Bt maize. The growth rate of snails exposed to cadmium decreased with exposure to increasing Cd concentrations and differed significantly between the no-nematode treatment and the treatments with nematode doses of one- and fourfold the recommended field dose. Snails treated with the highest dose of nematodes accumulated the highest cadmium concentrations.
Predicting world health organization toxic equivalency factor dioxin and dioxin-like polychlorinated biphenyl levels in farmed atlantic salmon (Salmo salar) based on known levels in feed
Authors: Berntssen Marc H. G. , Giskegjerde Tor Andre , Rosenlund Grethe , Torstensen Bente E. , Lundebye Anne-Katrine
Published: December 2006

Assimilation and elimination rate constant of dietary polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DLPCBs) with a World Health Organization toxic equivalency factor (WHO-TEF) were estimated in market-size Atlantic salmon (Salmo salar) using fish that were previously fed vegetable oil–based (low in PCDD/Fs and DLPCBs) or fish oil–based (high in PCDD/Fs and PCBs) diets. At the start of the kinetic trial, half the fish that were fed fish oils were fed vegetable oil feeds and inverted (cross-over design) for five months. The assimilation efficiencies of the PCDD/F congeners were more variable (3–89%) and, generally, were lower than those of the DLPCBs (70–80%). Among the PCDD/F congeners, the assimilation efficiency of the most toxic tetra- and pentachlorinated PCDD/Fs was greater than that of higher-chlorinated PCDD/Fs. Elimination rates for DLPCBs were higher than those for PCDD/Fs. Lower-chlorinated PCDDs had a lower elimination rate than the higher-chlorinated PCDDs, but no differences were observed among PCDF congeners or DLPCB congeners. Kinetic parameters were used to predict the level of WHO-TEF dioxins and DLPCBs in Atlantic salmon reared in a large-scale facility under commercial conditions. Predictions were based on preanalyzed levels of these organochlorines in feeds with three different replacement levels (0, 30, and 60%) of vegetable oil. A simple one-compartmental, first-order kinetic model was used to predict the level of sum WHO toxic equivalents for PCDD/Fs and DL-PCBs. The predicted values varied by 0 to 11% from the measured values in the commercially reared salmon.
Evasion of added isotopic mercury from a northern temperate lake
Authors: Southworth George , Lindberg Steven , Hintelmann Holger , Amyot Marc , Poulain Alexandre , Bogle MaryAnna , Peterson Mark , Rudd John , Harris R. , Sandilands Kenneth , Krabbenhoft David , Olsen Mark
Published: December 2006

Isotopically enriched Hg (90% 202Hg) was added to a small lake in Ontario, Canada, at a rate equivalent to approximately threefold the annual direct atmospheric deposition rate that is typical of the northeastern United States. The Hg spike was thoroughly mixed into the epilimnion in nine separate events at two-week intervals throughout the summer growing season for three consecutive years. We measured concentrations of spike and ambient dissolved gaseous Hg (DGM) concentrations in surface water and the rate of volatilization of Hg from the lake on four separate, week-long sampling periods using floating dynamic flux chambers. The relationship between empirically measured rates of spike-Hg evasion were evaluated as functions of DGM concentration, wind velocity, and solar illumination. No individual environmental variable proved to be a strong predictor of the evasion flux. The DGM-normalized flux (expressed as the mass transfer coefficient, k) varied with wind velocity in a manner consistent with existing models of evasion of volatile solutes from natural waters but was higher than model estimates at low wind velocity. The empirical data were used to construct a description of evasion flux as a function of total dissolved Hg, wind, and solar illumination. That model was then applied to data for three summers for the experiment to generate estimates of Hg re-emission from the lake surface to the atmosphere. Based on ratios of spike Hg to ambient Hg in DGM and dissolved total Hg pools, ratios of DGM to total Hg in spike and ambient Hg pools, and flux estimates of spike and ambient Hg, we concluded that the added Hg spike was chemically indistinguishable from the ambient Hg in its behavior. Approximately 45% of Hg added to the lake over the summer was lost via volatilization.
Response spectrum of fluoranthene and pentachlorobenzene for the fathead minnow (Pimephales promelas)
Authors: Schuler Lance J. , Landrum Peter F. , Lydy Michael J.
Published: December 2006

Internal body residue has been recognized as a potential dose metric for toxicological assessments. This relationship between body residue and biological effects, including both lethal and sublethal effects, is critically important for determining environmental quality in risk assessments. The present study identified the toxic equivalent body residues for fluoranthene (FLU) and pentachlorobenzene (PCBz) associated with mortality, reduced growth, and decreased hatchability in the fathead minnow. The toxic equivalent body residue was defined as the total of the parent compound and the organically extractable metabolites for FLU and of the parent compound only for PCBz, because no biotransformation was measurable. The lethal body residues corresponding to 50% mortality were 0.80 and 1.26 μmol/g wet weight for FLU and PCBz, respectively. As expected, residues associated with sublethal effects generally are 2- to 40-fold lower than the lethal residues for FLU and PCBz. Juvenile fish growth was the most sensitive endpoint examined for both compounds. The maximum allowable toxicant residues were 0.02 and 0.43 μmol/g wet weight for FLU and PCBz, respectively. The information collected from the present study will permit a greater understanding of residue-response relationships, which will be useful in risk assessments.
Reproducibility of binary-mixture toxicity studies
Authors: Cedergreen Nina , Kudsk Per , Mathiassen Solvejg Kopp , Sørensen Helle , Streibig Jens Carl
Published: December 2006

Binary-mixture studies often are conducted with the aim of elucidating the effect of one specific chemical on the biological action of another. The results can be interpreted in relation to reference models by the use of response-surface analyses and isobolograms. The amount of data needed for these analyses is, however, extensive, and the experiments therefore rarely are repeated. In the present study, we investigate the reproducibility of isobole shapes of binary-mixture toxicity experiments in terms of deviation from the reference model of concentration addition (CA), dose-level dependence, and isobole asymmetry. We use data from four herbicide mixtures tested in three to five independent experiments on the aquatic test plant Lemna minor and the terrestrial plant Tripleurospermum inodorum. The results showed that the variation both within and among experiments was approximately half the size for the aquatic test system compared to the terrestrial system. As a consequence, a consistent deviation from CA could be obtained in three of four herbicide mixtures for L. minor, whereas this was only the case for one or two of the herbicide mixtures tested on T. inodorum. For one mixture on T. inodorum, both CA synergism and antagonism were detected. Dose-dependent effects could not be repeated consistently, just as the asymmetry found in some isoboles could not. The study emphasizes the importance of repeating mixture toxicity experiments, especially for test systems with large variability, and using caution when drawing biological conclusions from the test results.
Differential sensitivity to Bacillus thuringiensis var. Israelensis and temephos in field mosquito populations of Ochlerotatus cataphylla (diptera: Culicidae): Toward resistance?
Authors: Boyer Sébastien , Tilquin Mathieu , Ravanel Patrick
Published: December 2006

In the present study, four populations of the same field mosquito species, Ochlerotatus cataphylla, were sampled over the Rhône-Alpes region (France), and their respective sensitivity to the organophosphate temephos and the bacterio-insecticide Bacillus thuringiensis var. israelensis (Bti) was measured. The results obtained in toxicological tests showed significant differences in the larval sensitivities of the four populations for both insecticides. These differences appeared to be related to the activity of the three main families of detoxifying enzymes: Cytochrome P450 monooxygenases, glutathione-S-transferases (GSTs), and esterases. All three enzyme families were significantly overexpressed in the less susceptible larval population, and after multiple regressions, GSTs and esterases came out as the most explicative variables of the larval sensitivity. Considering these results and the chemical history of the sites in terms of insecticide treatments, the hypothesis of cross-effects of insecticides leading to resistance acquisition to Bti in field organisms emerges.
Reproductive toxicity of dietary copper to a saltwater cladoceran, Moina monogolica daday
Authors: Wang Zao-Sheng , Kong Hai-Nan , Wu De-Yi
Published: December 2006

In the present study, the chronic toxicity of dietary copper to Moina monogolica Daday was investigated. Microalgal growth inhibition tests were conducted for 96 h with the green algae Chlorella pyrenoidosa exposed to copper. The 96-h median effective concentration (95% confidence interval) was 509.12 (388.68–629.56) μg/L. Then, C. pyrenoidosa was exposed for 96 h to a control and to seven dissolved copper concentrations. Cellular copper concentration accumulated in a dose-dependent manner and was plotted against cell density. These algae were used as food in a 21-d bioassay with M. monogolica in seawater to which no dissolved copper was added. Brood size was not reduced in the first brood, but significant reductions at all algal-exposure copper concentrations (44.78–817.17 μg/L) were observed in all subsequent broods, with increasing magnitude in each brood. Neither longevity nor number of broods per female was significantly affected, even at the highest copper exposure, though both endpoints did show a consistent downward trend with increasing copper exposure. Total reproduction, brood size, and net reproductive rate were decreased significantly in all dietary copper exposures (algae exposed to 44.78–817.17 μg/L). In contrast, the intrinsic rate of natural increase was reduced significantly only with algae exposed to greater than 619.27 μg/L, most likely because of the heavy influence of early reproduction on this metric. Because cell density in algal cultures decreased with increasing copper concentrations, it is possible that changes in the nutritional content of the algal diet could have played a role in causing the observed changes in reproduction of M. monogolica.
Mixture and single-substance toxicity of selective serotonin reuptake inhibitors toward algae and crustaceans
Authors: Christensen Anne Munch , Faaborg-Andersen Sofie , Flemming Ingerslev , Baun Anders
Published: December 2006

Selective serotonin reuptake inhibitors (SSRIs) are used as antidepressant medications, primarily in the treatment of clinical depression. They are among the pharmaceuticals most often prescribed in the industrialized countries. Selective serotonin reuptake inhibitors are compounds with an identical mechanism of action in mammals (inhibit reuptake of serotonin), and they have been found in different aqueous as well as biological samples collected in the environment. In the present study, we tested the toxicities of five SSRIs (citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline) as single substances and of citalopram, fluoxetine, and sertraline in binary mixtures in two standardized bioassays. Test organisms were the freshwater algae Pseudokirchneriella subcapitata and the freshwater crustacean Daphnia magna. In algae, test median effect concentrations (EC50s) ranged from 0.027 to 1.6 mg/L, and in daphnids, test EC50s ranged from 0.92 to 20 mg/L, with sertraline being one of the most toxic compounds. The test design and statistical analysis of results from mixture tests were based on isobole analysis. It was demonstrated that the mixture toxicity of the SSRIs in the two bioassays is predictable by the model of concentration addition. Therefore, in risk assessment based on chemical analysis of environmental samples, it is important to include the effect of all SSRIs that are present at low concentrations, and the model of concentration addition may be used to predict the combined effect of the mixture of SSRIs.
Predicting the toxicity of neat and weathered crude oil: Toxic potential and the toxicity of saturated mixtures
Authors: Di Toro Dominic M. , McGrath Joy A. , Stubblefield William A.
Published: December 2006

The toxicity of oils can be understood using the concept of toxic potential, or the toxicity of each individual component of the oil at the water solubility of that component. Using the target lipid model to describe the toxicity and the observed relationship of the solubility of oil components to log (KOW), it is demonstrated that components with lower log (KOW) have greater toxic potential than those with higher log (KOW). Weathering removes the lower-log (KOW) chemicals with greater toxic potential, leaving the higher-log (KOW) chemicals with lower toxic potential. The replacement of more toxically potent compounds with less toxically potent compounds lowers the toxicity of the aqueous phase in equilibrium with the oil. Observations confirm that weathering lowers the toxicity of oil. The idea that weathering increases toxicity is based on the erroneous use of the total petroleum hydrocarbons or the total polycyclic aromatic hydrocarbons (PAHs) concentration as if either were a single chemical that can be used to gauge the toxicity of a mixture, regardless of its makeup. The toxicity of the individual PAHs that comprise the mixture varies. Converting the concentrations to toxic units (TUs) normalizes the differences in toxicity. A concentration of one TU resulting from the PAHs in the mixture implies toxicity regardless of the specific PAHs that are present. However, it is impossible to judge whether 1 μg/L of total PAHs is toxic without knowing the PAHs in the mixture. The use of toxic potential and TUs eliminates this confusion, puts the chemicals on the same footing, and allows an intuitive understanding of the effects of weathering.
Aquatic toxicity of ethoxylated and propoxylated alcohols to Daphnia magna
Authors: Roberts Jayne F. , Marshall Stuart J. , Roberts David W.
Published: December 2006

Ethoxylated alcohols, which are used as nonionic surfactants, are known to act as general narcotics in acute aquatic toxicity; that is, they behave in the same way as nonsurfactant unreactive organic chemicals. The toxicity of such chemicals is well predicted by quantitative structure–activity relationships based solely on the logarithm of the octanol/water partition coefficient (log P), which can be calculated from structure. In the present study, we have shown, using experimental results, that a similar approach can be used to determine the toxicity of ethoxylate/propoxylate alcohols (i.e., containing propoxy [PO] and ethoxy [EO] units). Our calculations indicate that use of the Roberts position-dependent branching factor in calculating the PO group contribution is more appropriate than the Leo and Hansch branch factor. The resulting log P value for a PO group is 0.01; that is, the overall contribution to the final log P value is close to zero. On this basis, it is predicted that nonionic surfactants containing both EO and PO groups should have the same molar toxicity as surfactants based on the same parent alcohol and with the same number of EO groups but with no PO groups. This prediction has been confirmed in Daphnia acute toxicity tests. Furthermore, both EO/PO and EO-only nonionics are found to fit the same linear relationship between log P and toxicity.
Soft Sensing for Gas-Lift Wells
Authors: Bloemen Hayco , Belfroid Stefan , Sturm Wilco , Verhelst Frederic
Published: December 2006

This paper considers the use of extended Kalman filtering as a soft-sensing technique for gas lift wells. This technique is deployed for the estimation of dynamic variables that are not directly measured. Possible applications are the estimation of flow rates from surface and downhole pressure measurements or the estimation of parameters of a drift-flux model. By means of simulation examples, different configurations of sensor systems are analyzed. Finally, the estimation of drift-flux model parameters is demonstrated on real data from a laboratory setup.

Introduction

During the last 10 years, the industry has seen different downhole actuation technologies (commonly known as intelligent completions or under different trademarks) coming into existence. The goal of these technologies is ultimately to maximize the value of an asset by applying "right-time" optimization concepts borrowed from control engineering. Depending on the specific economics of the asset, this can be translated into more specific objectives such as speeding up of production, stabilization of unstable production, deferment of production of unwanted fluids, maximizing ultimate recovery, or a combination of some of the aforementioned short- and long-term objectives.

Control theory concepts of optimization by means of a feedback loop require means for determining the deviation between the actual response and the desired response of the system. In wells, this often boils down to some sort of multiphase flow measurement. Different accurate multiphase-measurement technologies have been matured during the last decade, and the industry seems to be crossing the chasm between the early-adopter and the early-follower stages. Often for control purposes, direct measurements with high absolute accuracy are not required, as long as the measurements give a good indication of the relative change in the property that needs to be optimized.

In different process industries, soft-sensing techniques were developed to determine variables where it is either impossible to directly measure the variables of interest or where it is economically not justifiable. In this paper, the concept of soft sensing is used; unmeasured dynamic variables (such as flow rates) are estimated from measured ones (i.e., pressures) by fitting a sufficiently accurate numerical model to the available measurements. We have looked at the gas lifted well application, where the lift gas rate may be controlled. Ideally this control would be based on directly measured multiphase flow rates, but in reality one often finds that this information is not available. Other measurements, such as surface and downhole pressure and temperature measurements, are more readily available and may be used for soft sensing.

The paper is organized in the following manner: first, the model of the gas lifted well is described; then, the soft-sensing concepts are explained; and, finally, different examples and configurations are shown in which this technology is applied for estimating multiphase flows.
Compositional Modeling of Retrograde Gas-Condensate Reservoirs in Multimechanistic Flow Domains
Authors: Ayala Luis F. , Ertekin Turgay , Adewumi Michael A.
Published: December 2006

A multimechanistic flow environment is the result of the combined action of a Darcian flow component (the macroscopic flow of the phase caused by pressure gradients) and a Fickian-like or diffusive flow component (diffusive flow caused by molecular concentration gradients) taking place in a hydrocarbon reservoir. The present work presents the framework needed for the assessment of the impact of multimechanistic flow on systems where complex fluid behavior—such as that of retrograde gas-condensate fluids—requires the implementation of compositional reservoir simulators. Because of the complex fluid behavior nature of gas-condensate fluids, a fully-implicit (IMPISC-type) compositional model is implemented and the model is used for the study of the isothermal depletion of naturally fractured retrograde gas reservoirs. In these systems, especially those tight systems with very low permeability (k < 0.1 md), bulk fluid flow as predicted by Darcy's law might not take place despite the presence of large pressure gradients. The use of an effective diffusion coefficient in the gas phase—which accounts for the combined effect of the different diffusion mechanisms that could take place in a porous medium—and its relative contribution to fluid recovery is discussed. The compositional tracking capabilities of the model are tested, and the conditions where Fickian flow can be the major player in recovery predictions and considerably overcome the flow impairment to gas flow posed by the eventual appearance of a condensate barrier—typical of gas-condensate systems—are investigated. Finally, a mapping that defines different domains where multimechanistic flow can be expected in compositional simulators of retrograde gas-condensate reservoirs is presented.

Introduction

In typical natural-gas reservoirs, all hydrocarbons exist as a single free gas phase at conditions of discovery. Depending on the composition of the initial hydrocarbon mixture in place and their depletion behavior, we recognize up to three kinds of natural gas reservoirs: dry gas reservoirs, wet gas reservoirs, and retrograde gas or gas-condensate reservoirs. The latter is the richest in terms of heavy hydrocarbons, and thus it is very likely to develop a second heavier hydrocarbon phase (liquid condensate) upon isothermal depletion. This situation is illustrated by Fig. 1. In contrast, dry gases and wet gases do not undergo phase changes upon reservoir depletion, as their phase envelope's cricondentherms are found to the left of the reservoir temperature isotherm.
What Is Perinatal Depression?
Authors: Voelker Rebecca
Published: March 2024

This JAMA Patient Page describes perinatal depression screening and diagnosis and available treatment options.
State Coverage and Reimbursement of Antiobesity Medications in Medicaid
Authors: Liu Benjamin Y. , Rome Benjamin N.
Published: March 2024

This study examines state Medicaid coverage policies for antiobesity medications and their trends in Medicaid reimbursement from 2011 to 2022.
Phase 2 Trial Evaluating Minocycline for Geographic Atrophy in Age-Related Macular Degeneration
Authors: Keenan Tiarnan D. L. , Bailey Clare , Abraham Maria , Orndahl Christine , Menezes Supriya , Bellur Sunil , Arunachalam Thilaka , Kangale-Whitney Cathy , Srinivas Sowmya , Karamat Ayesha , Nittala Muneeswar , Cunningham Denise , Jeffrey Brett G. , Wiley Henry E. , Thavikulwat Alisa T. , Sadda SriniVas , Cukras Catherine A. , Chew Emily Y. , Wong Wai T.
Published: March 2024

Importance

Existing therapies to slow geographic atrophy (GA) enlargement in age-related macular degeneration (AMD) have relatively modest anatomic efficacy, require intravitreal administration, and increase the risk of neovascular AMD. Additional therapeutic approaches are desirable.

Objective

To evaluate the safety and possible anatomic efficacy of oral minocycline, a microglial inhibitor, for the treatment of GA in AMD.

Design, Setting, and Participants

This was a phase 2, prospective, single-arm, 45-month, nonrandomized controlled trial conducted from December 2016 to April 2023. Patients with GA from AMD in 1 or both eyes were recruited from the National Institutes of Health (Bethesda, Maryland) and Bristol Eye Hospital (Bristol, UK). Study data were analyzed from September 2022 to May 2023.

Intervention

After a 9-month run-in phase, participants began oral minocycline, 100 mg, twice daily for 3 years.

Main Outcomes and Measures

The primary outcome measure was the difference in rate of change of square root GA area on fundus autofluorescence between the 24-month treatment phase and 9-month run-in phase.

Results

Of the 37 participants enrolled (mean [SD] age, 74.3 [7.6] years; 21 female [57%]), 36 initiated the treatment phase. Of these participants, 21 (58%) completed at least 33 months, whereas 15 discontinued treatment (8 by request, 6 for adverse events/illness, and 1 death). Mean (SE) square root GA enlargement rate in study eyes was 0.31 (0.03) mm per year during the run-in phase and 0.28 (0.02) mm per year during the treatment phase. The primary outcome measure of mean (SE) difference in enlargement rates between the 2 phases was −0.03 (0.03) mm per year (P = .39). Similarly, secondary outcome measures of GA enlargement rate showed no differences between the 2 phases. The secondary outcome measures of mean difference in rate of change between 2 phases were 0.2 letter score per month (95% CI, −0.4 to 0.9; P = .44) for visual acuity and 0.7 μm per month (−0.4 to 1.8; P = .20) for subfoveal retinal thickness. Of the 129 treatment-emergent adverse events among 32 participants, 49 (38%) were related to minocycline (with no severe or ocular events), including elevated thyrotropin level (15 participants) and skin hyperpigmentation/discoloration (8 participants).

Conclusions and Relevance

In this phase 2 nonrandomized controlled trial, oral minocycline was not associated with a decrease in GA enlargement over 24 months, compared with the run-in phase. This observation was consistent across primary and secondary outcome measures. Oral minocycline at this dose is likely not associated with slower rate of enlargement of GA in AMD.
In‐depth multiomic characterization of the effects of obesity in high‐fat diet‐fed mice
Authors: Li Boping , Chen Juanjuan , Ou Xiaobin , Liu Xiuli , Xu Zaoxu , Xiang Xuesong , Yang Yan , Wang Qi
Published: March 2024

High‐fat diet (HFD)‐fed mice have been widely used in the clinical investigation of obesity. However, the long‐term effect of HFD on gut microbiota and metabolites, plasma and liver metabolomics, colonic and liver transcriptomics remain largely unknown. In this study, 6‐week‐old C57BL/6J male mice fed with HFD for 14 weeks showed increased obesity‐related indexes including alanine aminotransferase, aspartate aminotransferase, total cholesterol, total triglyceride, free fatty acids, lipopolysaccharides, IL‐6, and TNFα. Furthermore, microbial diversity and richness were also significantly decreased. In the colon, genes involved in tryptophan metabolism, PPAR signaling pathway, cholesterol metabolism, and lipid localization and transport, were upregulated. While in the liver, MAPK signaling and unsaturated fatty acid biosynthesis were upregulated. Metabolomic analyses revealed decreased levels of glycerophospholipids and fatty acyl, but increased amino acids, coenzymes and vitamins, and organic acids in the colon, suggesting high absorption of oxidized lipids, while acyl‐carnitine, lysophosphatidylcholine, lysophosphatidylethanolamine, and oxidized lipids were reduced in the liver, suggesting a more active lipid metabolism. Finally, correlation analyses revealed a positive correlation between gut microbiota and metabolites and the expression of genes associated with lipid localization, absorption, and transport in the colon, and nutrients and energy metabolism in the liver. Taken together, our results provide a comprehensive characterization of long‐term HFD‐induced obesity in mice.
Effects of Electric Field‐Modulated Conductive Hydrogel on Osseoperception and Osseointegration of Dental Implants
Authors: Qin Wen , Li Ling , Niu Wen , Wang Wan‐Rong , Wu Dian‐Wei , Song Chang‐Geng , Gao Chang‐He , Mu Zhao , Tay Franklin R. , Jiao Kai , Niu Li‐Na
Published: March 2024

Achieving optimal implant restoration hinges on both robust osseointegration as the structural foundation and favorable osseoperception for advanced masticatory function. The significance of nerve innervation in the peri‐implant environment as the cornerstone of osseointegration and osseoperception is often underestimated. Despite the integral role of endogenous electric fields (EFs) in the human body, particularly in electrosensitive tissues like nerve tissue, the current approach involving external electrical stimulation is invasive and not clinically applicable. The present study introduces a conductive hydrogel designed to respond to endogenous EFs, aiming to foster nerve regeneration around dental implants to coordinate both osseointegration and osseoperception. The hydrogel promotes neurite outgrowth by upregulating intracellular Ca2+ concentration and activating subsequent pathways. Furthermore, the enhanced release of neuropeptides from neurocells improves the osteogenesis of osteoblasts. The impact of the conductive hydrogel on osseointegration and osseoperception is also thoroughly investigated in vivo. This conductive hydrogel represents a unique strategy for enhancing osseointegration and osseoperception within the endogenous EFs of the peri‐implant environment. This advancement opens the door to achieving the physiological and psychological integration of dental implants.
Carbon Quantum Dots Confined into Covalent Triazine Frameworks for Efficient Overall Photocatalytic H2O2 Production
Authors: Yang Yue , Guo Quanyou , Li Qingwei , Guo Liping , Chu Hongqi , Liao Lijun , Wang Xuepeng , Li Zhenzi , Zhou Wei
Published: March 2024

Porous organic polymers have an outstanding performance in the field of photocatalysis with the advantage of diverse structure composition and purposeful molecular design. However, the inherent high impedance and poor electrical conductivity of organic semiconductors still restrict the charge transfer efficiency and thus discount the photocatalytic performance. Herein, the study reports a highly conductive covalent triazine framework (CTF) loading carbon quantum dots (CQDs) into porous as electron transport medium. The addition of CQDs (0.5 wt%) can enhance the electronic conductivity of CTF by tenfold. In addition, the as‐prepared CQD‐CTFs express much‐promoted charge separation and transfer efficiency. Furthermore, the embedded CQDs can improve the oxidization capacity and increase the affinity of H+ due to the more negative zeta potential. The enhanced oxidizing ability and increased H+ affinity are positive for water oxidation reaction (WOR) and oxygen reduction reaction (ORR) process in hydrogen peroxide (H2O2) generation, respectively. The optimized CQD‐CTF exhibits a high H2O2 generation rate of up to 1036 µmol g−1 h−1 in pure water without any sacrificial agent under visible light, which is 4.6 times than pristine CTF. This work provides a new idea for efficient H2O2 production of organic semiconductors.
Surface Work Function Modifier to Modulate Electrolyte Decomposition on Negative Electrode in Lithium‐Ion Batteries
Authors: Byun Jooeun , Lee Chae Rim , Kim Wontak , Lee Min A , Jang Ho Yeon , Hwang Chihyun , Song Jun Ho , Yu Ji‐Sang , Back Seoin , Kim Ki Jae , Kim Hyun‐seung
Published: March 2024

The persistent decomposition of electrolytes on graphite and silicon electrodes in lithium‐ion batteries (LIBs) is typically mitigated by the formation of a solid electrolyte interphase (SEI). However, the inadequate formation and chemo‐mechanical degradation of SEI leads to re‐exposure of electrode to electrolyte, contributing to the deterioration of LIBs. To address this issue, tris(2,4‐pentanedionato)indium(III) (InAc) is incorporated into the work function tailoring additive. While conventional additives strengthen the chemo‐mechanical properties of SEI through compositional modifications derived from specific elements, InAc uniquely alters charge transfer across the electrode surface, facilitated by high or low work function layer. This additive establishes an interlayer between the SEI and graphite/SiO surfaces, attributed to its tailored lowest unoccupied molecular orbital energy level. Consequently, the exposure of graphite surface to the electrolyte is minimized by interlayer during cycling. The interlayer possesses a higher work function than lithiated graphite and suppresses further electrolyte decomposition on graphite. In contrast, the interlayer on SiO decreases work function of SiO surface, which promotes the formation of inorganic SEI on SiO. Hence the degradation of SEI is suppressed with LiIn layer at SiO electrode. This leads to a reduction in the ongoing accumulation of SEI, thereby enhancing durability of LIBs.
Decoupled Crystallization and Particle Growth of BiVO4 via Rapid Thermal Process for Enhanced Charge Separation
Authors: Wang Shujie , Liu Bin , Wang Qingzhen , Gong Zichen , Zhang Peng , Wang Tuo , Gong Jinlong
Published: March 2024

BiVO4 is one of the most promising candidates for photoelectrochemical water oxidation. However, the poor crystallinity and short hole diffusion length limit its charge separation. One bottleneck stems from the contradiction between high crystallinity and small particles via conventional furnace heating processes. This paper describes the design and fabrication of BiVO4 photoanodes via rapid thermal process (RTP), rather than furnace heating, to decouple the constraints between nucleation, crystallization, and growth processes of BiVO4. The higher heating ramp rate of RTP compared with furnace heating promotes the fast diffusion of reactant molecules, which elevates the nucleation rate above the particle growth rate of BiVO4, leading to small particles with high crystallinity. Moreover, the ultra‐high heating temperature makes it possible to crystallize the small BiVO4 particle within a short time. Thus, a high crystallinity can be obtained for the RTP‐treated BiVO4 while maintaining small particle size, achieving a charge separation efficiency of up to 82%, 30% higher than that of furnace‐treated BiVO4 photoanode.
Zein‐Based Triple‐Drug Nanoparticles to Promote Anti‐Inflammatory Responses for Nerve Regeneration after Spinal Cord Injury
Authors: Wang Jingxuan , Lin Yan , Li Chunhan , Lei Fei , Luo Hongli , Jing Pei , Fu Yao , Zhang Zhirong , Wang Changguang , Liu Zerong , Jiang Jun , Zhou Meiling , Du Xingjie , Liu Zhongbing , Zhou Xiangyu , Sun Xiaoduan , Zhong Zhirong
Published: March 2024

Defects in autophagy contribute to neurological deficits and motor dysfunction after spinal cord injury. Here a nanosystem is developed to deliver autophagy‐promoting, anti‐inflammatory drugs to nerve cells in the injured spinal cord. Celastrol, metformin, and everolimus as the mTOR inhibitor are combined into the zein‐based nanoparticles, aiming to solubilize the drugs and prolong their circulation. The nanoparticles are internalized by BV2 microglia and SH‐SY5Y neuron‐like cells in culture; they inhibit the secretion of inflammatory factors by BV2 cells after insult with lipopolysaccharide, and they protect SH‐SY5Y cells from the toxicity of H2O2. In a rat model of spinal cord injury, the nanoparticles mitigate inflammation and promote spinal cord repair. In the in vitro and in vivo experiments, the complete nanoparticles function better than the free drugs or nanoparticles containing only one or two drugs. These results suggest that the triple‐drug nanoparticles show promise for treating spinal cord injury.
Multiphase Under‐Liquid Biofabrication With Living Soft Matter: A Route to Customize Functional Architectures With Microbial Nanocellulose
Authors: Lu Yi , Chun Yeedo , Shi Xuetong , Wang Dong , Ahmadijokani Farhad , Rojas Orlando J.
Published: March 2024

The growth of aerobic microbes at air–water interfaces typically leads to biofilm formation. Herein, a fermentative alternative that relies on oil–water interfaces to support bacterial activity and aerotaxis is introduced. The process uses under‐liquid biofabrication by structuring bacterial nanocellulose (BNC) to achieve tailorable architectures. Cellulose productivity in static conditions is first evaluated using sets of oil homologues, classified in order of polarity. The oils are shown for their ability to sustain bacterial growth and BNC production according to air transfer and solubilization, both of which impact the physiochemical properties of the produced biofilms. The latter are investigated in terms of their morphological (fibril size and network density), structural (crystallinity) and physical–mechanical (surface area and strength) features. The introduced under‐liquid biofabrication is demonstrated for the generation of BNC‐based macroscale architectures and compartmentalized soft matter. This can be accomplished following three different routes, namely, 3D under‐liquid networking (multi‐layer hydrogels/composites), emulsion templating (capsules, emulgels, porous materials), and anisotropic layering (Janus membranes). Overall, the proposed platform combines living matter and multi‐phase systems as a robust option for material development with relevance in biomedicine, soft robotics, and bioremediation, among others.
Ratiometric Fluorescence Optical Fiber Enabling Operando Temperature Monitoring in Pouch‐Type Battery
Authors: Wang Yuzhen , Zhang Qimeng , Yang Chenghao , Xia Zhiguo
Published: March 2024

Thermal characteristics are essential for improving the performance and monitoring the status of Li‐ion batteries (LIBs). However, it is a challenge to design efficient and facile sensing materials for the detection of the in situ temperature of a working LIB. Herein, a ratiometric fluorescence optical fiber is developed and real‐time temperature monitoring is performed with a measurement accuracy of 0.12 °C, and the feasibility based on this polymer optical fiber composed of NaLaTi2O6:Yb/Er phosphors is verified in a pouch‐type battery. During the charging and discharging cycles, the in situ temperature is instantaneously conveyed, revealing the internal situation of LIBs. This article further dwells on the thermal characteristics in constant current (CC)/constant voltage charging and CC discharging processes at different C‐rates and the battery failure when operated at low temperatures (0 °C). This work demonstrates an innovative strategy for operando solitary temperature monitoring conducted by ratiometric fluorescence optical fiber.
Tunable LiZn‐Intermetallic Coating Thickness on Lithium Metal and Its Effect on Morphology and Performance in Lithium Metal Batteries
Authors: Bela Marlena M. , Schmidt Christina , Neuhaus Kerstin , Hering Tobias , Stan Marian C. , Winter Martin , Börner Markus
Published: March 2024

Lithium metal batteries are promising next‐generation rechargeable batteries with high energy density. However, the high reactivity of lithium metal leads to an undesirable growth of high surface area lithium during electrodeposition and ‐dissolution and remains a key challenge that must be addressed to enable commercialization. Modification of the Li metal surface to obtain protective coatings is a common method to overcome these challenges. In this study, the influence of the thickness of an intermetallic coating on Li metal is investigated after application by means of thermal evaporation. In addition, the relevance of pre‐treatments in reducing the native layer thickness and surface roughness by roll‐pressing Li metal prior to coating is demonstrated. Morphological analyses are performed on cross‐sections prepared under cryogenic conditions to investigate the origin of high surface area lithium growth and coating cracks after electrodeposition and ‐dissolution processes. The results obtained support the conclusion that the exclusive combination of roll‐pressed Li metal foil followed by coating reduces overvoltage and improves cycle life at elevated current densities.
Graphene Aerogel‐Based Pressure Sensors with Gradient Structure for Subtle Physiological Signals and Motion Monitoring
Authors: Liu Jing , Li Wenbo , Li Jing , Wang Keke , Wen Yating , Wang Jiawei , Zhang Baoxun , Li Jiongli , Wang Xudong , Huang Zhandong
Published: March 2024

High‐performance flexible wearable pressure sensors require the simple preparation method coupled with a well‐designed structure. Graphene aerogel has garnered significant attention as a flexible pressure sensor due to its exceptional features such as high porosity, favorable compressibility, and fine conductivity. However, it remains challenging to precisely control the 3D structure of the graphene aerogel within the sensors, which limits the detection sensitivity and application range. Here, a freeze‐assisted transfer printing strategy (FATPS) is proposed for fabricating a high‐performance graphene aerogel‐based sensor with the gradient structures. Compared to sensors prepared using mold methods, the sensitivity of the sensor produced through FATPS can be enhanced by nearly tenfold. Furthermore, the gradient structure empowers the graphene pressure sensor with excellent reliability and rapid response time (50 ms) within the pressure range of 0.1–50 kPa. The sensor exhibits the capability to monitor and recognize various physiological activities, including pulse, vocalization, coughing, swallowing, and finger bending. It is expected that the sensor has remarkable potential applications in medical diagnosis, disability aid, and athletic injury prevention and so on.
Compact Mid‐Infrared Spectrometer Using Continuously Variable Infrared Filter and Microbolometer Array for Simple and Fast Measurement of Molecular Mid‐IR Spectra
Authors: Jeon Taeyoon , Nateghi Amirhossein , Choi Changsoon , Jewell Jack , Scherer Axel
Published: March 2024

The mid‐infrared (mid‐IR) region is attractive for spectroscopy because this range has molecular fingerprint information. Existing FTIR‐based systems are limited by their complex optical systems, highlighting the ongoing necessity to advance miniaturization and simplify these systems. Here, a compact mid‐IR spectroscopy is introduced in the mid‐IR range, utilizing a continuously variable mid‐IR filter. This filter is made from Germanium (Ge) and BaF2 and is produced using physical vapor deposition. Continuously varying wavelengths of mid‐IR light are transmitted from different areas of the filter. These different wavelengths of light enter each pixel of the microbolometer array. Calibration is conducted using a sample material to match each pixel of the microbolometer array to its corresponding wavelength. Additionally, a deconvolution algorithm is applied to sharpen the acquired spectrum. This results in acquisition of high signal‐to‐noise ratio mid‐IR spectra in the LWIR region. Using this technology, mid‐IR spectroscopy for several types of samples like polymer film, and gas molecules is possible. In addition, by adopting total internal reflection, it is possible to measure non‐uniform thickness samples, such as liquid droplets.
Sb/X (X = Mn, Er, Ho) Co‐Doped Lead‐Free Double Perovskite Cs2NaInCl6 for Single‐Component White Light Emission
Authors: Xu Hanqi , Liu Jing , Hu Qichuan , Yu Jinyang , Han Qiuju , Wu Wenzhi
Published: March 2024

Recently, the incorporation of transition‐metal ions into lead‐free double perovskite has garnered considerable attention for improving the lattice environment and enhancing photoluminescence (PL) to achieve white light emission. Here, Sb/X (Mn, Er, Ho) co‐doped Cs2NaInCl6 (CNIC) microcrystals (MCs) synthesized by conventional hydrothermal method are developed for single‐component white light emission with various photoinduced transition mechanisms. Sb doping in CNIC MCs causes the breaking of non‐parity forbidden transition under 360 nm laser excitation and results in blue emission; Sb/X co‐doping for CNIC MCs successfully broadens the spectrum with multi‐peak emission, which consists of unique X‐peak emission and blue emission peaked at 445 nm. The energy transfer channels from both free excitons state of CNIC and self‐trapping excitons (STEs) state of [SbCl6]3− to X ion are proved and studied by use of steady‐state and time‐resolved PL spectroscopy. Among them, Sb/Er co‐doped CNIC MCs show unique dual‐mode PL under 360 and 980 nm laser excitation. Single‐component white light emitting diode is successfully fabricated by adjusting the composition of Sb/X co‐doped CNIC MCs, which provides an alternative path for realizing single‐component white light illumination.
N‐Doped Carbon‐Quantum‐Dot‐Integrated Colorimetric System for Visible Photoprinting and Oxygen Sensing
Authors: Liu Meng , Liu Zixiao , Wen Zeyulong , Yu Nuo , Macharia Daniel K. , Zhu Meifang , Chen Zhigang
Published: March 2024

The design of light‐responsive color switching systems (LCSs) is essential to the implementation of rewritable paper and oxygen detection. Previous LCSs rely on metal‐based semiconductor photocatalysts which are expensive and pose metal‐leaking risk. To solve the issue, for the first time, nitrogen‐doped carbon quantum dots (N‐CQDs) are reported as metal‐free photocatalyst for visible photoprinting and oxygen sensing. On N‐CQD surface, the decorated amino and hydroxyl groups act as hole scavengers and thus realize visible‐light‐responsive single and multiple color switching, after mixing with redox‐sensitive dyes. Combined with polymeric substrates, LCS rewritable papers can be fabricated and exhibit rapid decoloration performances under 420 nm light irradiation, due to the reduction of dye by photogenerated electrons from N‐CQDs. After the decoloration, efficient color reversion can be realized by the oxidization of dye in ambient air (O2). By taking advantage of the controlled recoloration kinetics, an oxygen sensor can be attained for visual quantitative analysis of atmospheric conditions with color variations. These results assist the future development of nonmetal color switching systems for superior functional design of photoprintable papers and colorimetric oxygen sensors.