Environmental Specimens Research Articles

Cu-curcumin nanozyme for detection of Cr(VI) through an off-on strategy based on peroxidase mimicking activity.

Hexavalent chromium ions (Cr(VI)) possess inherent toxicity and propensity for bioaccumulation in the environment. Herein, a Cu-curcumin nanozyme was synthesized via a one-pot solvothermal method. Based on the high peroxidase-like activity of the Cu-curcumin nanozyme, a novel and economical colorimetric platform has been developed for Cr(VI) assay. In the presence of hydrogen peroxide (H2O2), the Cu-curcumin nanozyme can catalyze the transformation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) into the blue product oxTMB. 8-Hydroxyquinoline (8-HQ) can inhibit the catalysis of the Cu-curcumin/TMB/H2O2 system, causing the blue color to fade. With the addition of Cr(VI), the peroxidase-like activity of the Cu-curcumin nanozyme is increased significantly, leading to the restoration of the Cu-curcumin/TMB/H2O2 system color. After optimization of the experimental parameters, a novel colorimetric sensor for Cr(VI) assay has been successfully developed with a low limit of detection (LOD) of 31.5 nM, affirming its potential for accurate Cr(VI) quantification in environmental specimens. In addition, paper strips integrated with a smartphone platform enhance the versatility and portability of the Cr(VI) assay, achieving an LOD of 0.1 μM.

Plasticizer exposure in Germany from 1988 to 2022: Human biomonitoring data of 20 plasticizers from the German Environmental Specimen Bank.

The German Environmental Specimen Bank (ESB) annually archives 24-h urine samples since the early 1980s. In this study, we analyzed 420 of these samples from the years 2014 to 2022 for metabolites of 18 phthalates and two substitutes. We merged the new data with the data from previous measurement campaigns to a combined dataset of 1825 samples covering a 35-year period from 1988 to 2022 to investigate time trends, calculate daily intakes and perform an anti-androgenic mixture risk assessment. With the extended set of 41 biomarkers, we are now able to monitor the exposure to all EU-labelled reprotoxic phthalates. Most phthalate exposures continued to decrease since first measurements in the 80s, with biggest drops for DnBP (96.6%) and DEHP (90.9%). DiNP and DiDP, seen on the rise in earlier campaigns, now declined. Exposures to the newly included, reprotoxic phthalates were generally negligible. Regarding mixture risk, 5% of the highly exposed still exceeded the Hazard Index (HI) of 1 in 2009. In the current measurement campaign only three individuals (0.7%) exceeded the HI of 1 (with exceedances still driven by DEHP and DnBP).In 2022, 20% of the individuals still had an HI > 0.2, which we propose as a benchmark for interpreting phthalate mixture risk, considering concurrent exposures to other anti-androgens. Exposure to the substitutes DINCH and DEHTP continues to increase, with daily intakes of DEHTP exceeding those of DEHP since 2018. Compared with the United States (US) National Health and Nutrition Examination Survey (NHANES) phthalate exposures seem to align, except for DEHTP with up to ten times higher levels in the US. Human biomonitoring (HBM) is the ideal tool to capture actual mixture exposures per individual, integrating all external exposure sources and pathways, thus we will continue to use HBM in exposure and risk assessment of phthalates and other (anti-androgenic) chemicals.

Detection of Mycobacterium chimaera in medical device water samples by customised real time PCR using a InGenius platform

Mycobacterium chimaera, belonging to the Mycobacterium avium complex, is an opportunistic environmental mycobacterium which has been isolated from medical device water samples such as Heater Cooler Units (HCU). Laboratories currently use culture-based diagnostic methods to detect M. chimaera, but these take a long time to obtain results. The aim of this study is to test and define the Limit of Detection (LoD) of a Real-Time Polymerase Chain Reaction test (RT-PCR) specific for M. chimaera, using a sample-to-result InGenius platform, performed on medical device water samples collected at the referral centre for the detection of mycobacteria from environmental specimens of Bologna, Italy. A total of 285 water samples were included in this study. The sensitivity and specificity of RT-PCR compared to culture were 60.5% and 98.8% respectively, with an overall agreement of 82.1% and a positive predictive value of 97.4%. The LoD calculated was approximately 2900 CFU/ml. In conclusion, this study confirmed that detection of M. chimaera with RT-PCR could support culture-based methods in reducing the time necessary to identify highly colonised HCUs, with high positive predictive values. Therefore, we suggest performing this customised RT-PCR on concentrated decontaminated water samples, shutting down and thoroughly disinfecting positive HCUs, to reduce the risk of patient infection.

Large, protracted, multispecies and multiclonal spread of VIM-type Metallo-ß-Lactamase-Producing Enterobacterales in an Italian Hospital.

Carbapenem-resistant Enterobacterales, particularly those producing carbapenemases (CPE), pose a major threat to human health, being listed among critical-priority resistant pathogens by the World Health Organization. In this study we report on a large nosocomial spread of CPE of different species producing VIM-type carbapenemases, and on the infection prevention and control measures thata were adopted to contrast the spread. Conventional culture and molecular methods were used for detection and identification of VIM-positive CPE (VIM-CPE) causing infections or colonizing patients or present in environmental specimens. Whole genome sequencing analysis of selected isolates was carried out to investigate clonal relatedness. Basic (active surveillance, contact precautions, close contacts screening, cases cohorting, surface cleaning, hand hygiene) and advanced (weekly point prevalence surveys for rectal colonization, additional training of healthcare workers, extraordinary ward sanification, extraordinary maintenance interventions, and environmental microbiological screening, single-use equipment, ward re-location) infection prevention and control (IPC) measures were implemented to contrast the spread. Spread of VIM-CPE involving 151 patients (mostly colonizations) was documented in a single hospital ward from November 2021 to December 2023. The spread involved several different species of Enterobacterales, with clonal expansion documented in some cases. Implementation of basic and advanced IPC measures was temporarily successful at mitiganting the spread, but multiple relapses were observed suggesting the presence of an unidentified environmental reservoir. The study highlights the potential of VIM-CPE to cause large and complex nosocomial outbreaks in hospital environments, and underscores the challenges that can be encountered for their control by IPC practices.

Designing a Simple Quinoline-Based Chromo-Fluorogenic Receptor for Highly Specific Quantification of Copper (II) Ions: Environmental and Bioimaging Applications.

Many industries use copper metal ions (Cu2+ ions), and their salts are utilized as supplemental materials in both agriculture and medicine. Identifying and monitoring these Cu2+ ions in biological and environmental specimens is crucial due to their association with several health issues. In this investigation, we have designed a simple quinoline-based receptor (E)-3-(((2,4-di-tert-butyl-5-hydroxyphenyl)imino)methyl)-6-methoxyquinolin-2(1H)-one (QAP) containing imine functional groups to inspect its capability to identify metal ions in a semi-aqueous medium. The photophysical characteristics and structural confirmation of the receptor QAP were investigated using various spectroscopic techniques. Among various metal ions, the receptor QAP displayed an intense color shift from slightly yellow to strong yellow in the existence of Cu2+ ions, as visualized by the nude eye. Furthermore, the fluorescence spectral maximum wavelength at 485 nm and the strong cyan fluorescence color were quenched upon introducing Cu2+ ions. The alteration in the spectral and colorimetric features of QAP with Cu2+ ions is due to coordination complex formation. The present sensor shows the linear range from 3 to 69 μM, subsequent in a computed limit of detection as 3.16 nM, which is much lower than that of the maximum threshold of Cu2+ ions in drinking water set by WHO. Therefore, the receptor can respond to Cu2+ ions sensing in two ways: by changing color and by quenching fluorescence. The binding mode of the Cu2+ ions to the functional groups of the receptor QAP is a 1:1 stoichiometry, according to ESI-mass, Job's plot analysis, and density functional theory (DFT) computations. The practical utility of the fluorescent receptor QAP was applied for Cu2+ ions determination in environmental samples (drinking, tap, and dam water) and cancer cells (HeLa cells).

Service life evaluation of marine reinforced concrete structures in coastal soda residue soil subjected to chloride attack

In chloride salt environments, the corrosion of steel reinforcements due to chloride ions intrusion into concrete is the main cause of the durability failure of reinforced concrete structures (RCSs). The chloride content included in coastal soda residue soil (SRS) foundations with a high moisture content has been measured to be 2–3 times that of seawater, which seriously threatens the durability of RCSs built in the SRS environment. Compared with marine tidal environments, the influence of SRS corrosive environment with a high moisture content and high chloride ions content on the chloride ions transport behaviours and the service life for the marine RCSs remains unclear. Therefore, for this paper, an indoor experimental study on chloride ions intrusion into the marine concrete specimens in a coastal SRS environment was carried out. The concentration profiles and transport characteristics of chloride ions within concrete in a real SRS environment with a semi-buried zone (SBZ) and a fully buried zone (FBZ) and in a simulated salt solution (SSS) environment of SRS were revealed. The measured results of chloride transport in concrete specimens exposed to the marine tidal zone (MTZ) were used as the control group to quantify the differences in chloride transport behaviours between concrete buried in the coastal SRS environment and that in the MTZ (marine tidal zone). Chloride transport models of concrete in coastal SRS and MTZ (marine tidal zone) environments were built by means of the Fick's second law of diffusion. Taking a certain marine RCS as an example, the service lives of this structure in coastal SRS and MTZ (marine tidal zone) environments were evaluated via this paper’s proposed chloride transport models and then compared. Results indicated that the predicted service life of the RCS in the FBZ (fully buried zone) is the longest, followed by that in the MTZ (marine tidal zone), and that in the SBZ (semi-buried zone) is the shortest. The service lives of the marine RCSs in the FBZ (fully buried zone) and MTZ (marine tidal zone) were approximately 1.37 times and 2.76 times that of the SBZ (semi-buried zone), respectively.

Recent Progress and Applications of Advanced Nanomaterials in Solid-Phase Extraction.

Sample preparation maintains a key bottleneck in the whole analytical procedure. Solid-phase sorbents (SPSs) have garnered increasing attention in sample preparation research due to their crucial roles in achieving high clean-up and enrichment efficiency in the analysis of trace targets present in complex matrices. Novel nanoscale materials with improved characteristics have garnered considerable interest across different scientific disciplines due to the limited capabilities of traditional bulk-scale materials. The purpose of this review is to offer a thorough summary of the latest developments and uses of SPSs in preparing samples for chromatographic analysis, focusing on the years 2020-2024. The techniques for preparing SPSs are examined, such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs), carbon nanoparticles (CNPs), molecularly imprinted polymers (MIPs), and metallic nanomaterials (MNs). Examining the pros and cons of different extraction methods, including solid-phase extraction (SPE), magnetic SPE (MSPE), flow-based SPE (FBA-SPE), solid-phase microextraction (SPME), stir-bar sorptive extraction (SBSE), and dispersive SPE (DSPE), is the main focus. Furthermore, this article presents the utilization of SPE technology for isolating common contaminants in various environmental, biological, and food specimens. We highlight the persistent challenges in SPSs and anticipate future advancements and applications of novel SPSs.

Nafion/graphite-bismuth nanoplate with a vibration unit for portable heavy metal ion detection

Contamination of natural resources, particularly water sources, by heavy metal ions, even at low concentrations, poses a significant threat to ecosystems and human health, underscoring the importance of developing sensors with point-of-use (POU) applications. To that end, a vibration-unit-equipped portable electrochemical system (vPES) capable of extremely sensitive detection of Pb2+ and Cd2+ in water is reported herein. The vibration unit enhances sensitivity by facilitating sample diffusion, and its compactness makes it suitable for point-of-use applications through mobile phone connectivity. The system also integrates Nafion and a graphite/bismuth-nanoplate-functionalized screen-printed carbon electrode to detect heavy metals efficiently. The approach implemented in this study and validated through experiments and simulations suggests that vibration-based mixing leads to 540 % and 511 % higher Pb2+ and Cd2+ detection efficiencies, respectively, than those in the absence of vibration. Additionally, the sensor exhibits the limits of detection of 0.98 and 1.65 nM for Pb2+ and Cd2+, respectively, in laboratory environments. Samples collected from the Nakdong River in Korea and real environmental specimens—freshwater, soil, and serum—validate the detection performance. Overall, this study highlights the potential of vPES as a rapid, sensitive POU sensor for heavy metal detection, thereby bolstering environmental and public health monitoring efforts.

Downstream effects of the pandemic? Spatiotemporal trends of quaternary ammonium compounds in suspended particulate matter of German rivers

During the SARS-CoV-2 pandemic, the preventive use of antimicrobials such as quaternary ammonium compounds (QACs) surged worldwide. As cationic and surface-active biocides, QACs are only partly removed during wastewater treatment and may cause adverse ecological effects in the downstream environment. To understand the environmental consequences of increased disinfectant use during the pandemic, we investigated spatiotemporal QAC concentration trends in the suspended particulate matter (SPM) of three diverse German rivers. Covering pooled annual SPM samples from 2006–2021 and monthly samples from 2018–2021 collected by the German Environmental Specimen Bank, 31 QACs were quantified by high performance liquid chromatography–mass spectrometry. ∑QAC concentrations in annual samples differed by more than tenfold between rivers in the order Saar (average 6.7 µg/g) > Rhine (0.9 µg/g) > Mulde (0.3 µg/g). The strongest potential pandemic imprint was however observed in the Mulde (+67 %) and Rhine (+22 %). Besides pandemic dynamics, also seasonal variation and mineral content of SPM tentatively affected QAC concentrations. Exceedance of predicted no-effect concentrations for sediment suggest ecotoxicological risks for long-chained QACs already before the pandemic. Our study thus highlights the importance of monitoring the environmental effects of antimicrobial use during pandemics and calls for an urgent minimization of non-essential applications.

Exposure of young German adults to the anti-dandruff agent climbazole from 2002 to 2022: Analysis of specific biomarkers in urinary samples

The fungicide climbazole is mainly used as an anti-dandruff (AD) agent in cosmetics, such as shampoos or other hair care products. Consequently, an exposure of the general population seems likely because many people suffer from dandruff. We have analyzed urine samples from the German Environmental Specimen Bank (ESB) for two specific climbazole biomarkers, namely (OH)2-climbazole and cx–OH–climbazole, in samples collected in the years 2002, 2007, 2012, 2017 and 2022. (OH)2-Climbazole was determined diastereoselectively, hence three analytes are discussed ((OH)2-climbazole 1, (OH)2-climbazole 2 and cx–OH–climbazole). The study population consisted of 300 students (150 male, 150 female) aged between 20 and 29 at the time of sampling from Halle/Saale in Germany. Most samples under scrutiny did not contain any climbazole metabolites in levels above the limit of quantification (LOQ, 0.5 μg/L for either analyte), only in 16 samples at least one analyte could be quantitated. Even the sample with the highest metabolite concentrations (10.23 μg/L (OH)2-climbazole and 2.53 μg/L cx–OH–climbazole) barely reached the urinary concentrations found in an excretion kinetics study after the typical application of a climbazole-containing shampoo in three volunteers. As a result, estimated daily intakes (max. 1.8 μg/kg bw/d) lay below the subchronic NOAEL (15 mg/kg bw/d) and NOEL (5 mg/kg bw/d) by a factor of more than 8300 and 2700, respectively. The evaluation of the climbazole burden of the general population gives valuable insights for the authorities on the effect of legal restrictions.

Establishment of a rapid and sensitive ic-ELISA for the detection of thiacloprid residues in honey and medicinal herbs using a novel highly specific monoclonal antibody

Thiacloprid is one of the first generation of neonicotinoid insecticide with a chloropyridine structure like imidacloprid and acetamiprid. Recent studies have revealed its environmental and non-target organism toxicity, leading to restrictions on its use in many countries and regions. Despite limitations, thiacloprid has been detected in various environmental samples, food sources, and biological specimens, posing a significant threat to human health, necessitating advanced detection methods for monitoring. In this study, a highly specific monoclonal antibody against thiacloprid via a multi-immunogen strategy was prepared and a rapid and sensitive enzyme-linked immunosorbent assay for the detection of thiacloprid residues in honey and medicinal herbs was established. The half maximal inhibitory concentration (IC50) of this method was 0.38 ng/mL, improving the sensitivity by 1.2−480.6 times compared to existing reports, and the limit of detection (IC20) was 0.097 ng/mL. The method was successfully applied to the determination of thiacloprid residues in honey and medicinal herbs (Crataegi fructus, Citri reticulatae pericarpium), achieving recovery rates ranging from 87.50 % to 116.11 %. The obtained results were verified using the LC-MS/MS method. The multi-immunogen strategy proposed in this study provides an approach for the preparation of highly sensitive and specific monoclonal antibodies, and immunoassay established based on it has good application prospects in complex matrices.

A new understanding of the alkali-silica reaction expansion in concrete using a hybrid ensemble model

Alkali-Silica Reaction (ASR) is a critical issue affecting the durability of concrete structures, leading to significant long-term maintenance costs and safety concerns. This study addresses the need for accurate prediction of ASR-induced expansion in concrete, leveraging advanced machine learning techniques. Two hybrid ensemble methods, the inverse variance method and the artificial neural network-based ensemble method, were proposed to integrate the individual models to enhance the predictive capabilities. A comprehensive experimental database comprising over 1997 sets of ASR expansion data was collected from relevant literature with the environmental conditions, specimen geometry and material composition as the input variables and specimen strain as the output variable. The findings indicate that the predictive performance of individual models falls short of the performance of the hybrid ensemble machine learning model, with the inverse variance-based ensemble model exhibiting the highest performance (R = 97.2 %, RMSE = 0.066 mm). The Shapley Additive Explanations analysis reveals that the most influential factors include reaction days, alkali content, aggregate particle size, and silica content, contributing to up to 35 % of the variation in ASR expansion. This work offers valuable insights for the efficient assessment of durability of concrete structures concerning ASR expansion.

Network analysis to reveal the most commonly detected compounds in predator-prey pairs in freshwater and marine mammals and fish in Europe

Marine and freshwater mammalian predators and fish samples, retrieved from environmental specimen banks (ESBs), natural history museum (NHMs) and other scientific collections, were analysed by LIFE APEX partners for a wide range of legacy and emerging contaminants (2545 in total). Network analysis was used to visualize the chemical occurrence data and reveal the predominant chemical mixtures for the freshwater and marine environments. For this purpose, a web tool was created to explore these chemical mixtures in predator-prey pairs. Predominant chemicals, defined as the most prevalent substances detected in prey-predator pairs were identified through this innovative approach. The analysis established the most frequently co-occurring substances in chemical mixtures from AP&P in the marine and freshwater environments. Freshwater and marine environments shared 23 chemicals among their top 25 predominant chemicals. Legacy chemical, including perfluorooctanesulfonic acid (PFOS), brominated diphenyl ethers (BDEs), polychlorinated biphenyls (PCBs), hexachlorobenzene and mercury were dominant chemicals in both environments. Furthermore, N-acetylaminoantipyrine was a predominant pharmaceutical in both environments. The LIFE APEX chemical mixture application (https://norman-data.eu/LIFE_APEX_Mixtures) was proven to be useful to establish most prevalent compounds in terms of number of detected counts in prey-predator pairs. Nonetheless, further research is needed to establish food chain associations of the predominant chemicals.

Combating coal-burning-borne endemic arsenism in Shaanxi Province, Northwest China: The impact of high-arsenic coal ban, improved cook-stoves, and health education

To eliminate the epidemic of coal-burning-borne endemic arsenism (CBBA), our study organized and implemented comprehensive measures including high-arsenic coal ban, improved cook-stoves, and health education. We also aimed to promote the application value of these measures in preventing and controlling CBBA to the world. From 2004 to 2005, through a stratified random sampling method, we selected 58,256 individuals to investigate the prevalence of CBBA and the arsenic levels in 1287 environmental and biological specimens. The prevalence of CBBA was 19.26 % and significantly associated with the arsenic levels in coal, pepper, corn and hair, which were at or exceeded national upper limits. To timely prevent and control the disease, the comprehensive measures have been implemented since 2005 to present. Comparison and correlation analyses were utilized to evaluate the effectiveness of these measures in reducing the prevalence of CBBA. According to statistics, 73 high-arsenic coal mines were banned and over 99 % households in endemic areas accepted stove improvements and diversified health education. Monitoring studies during 2010–2019 has confirmed that these measures led to a decrease in urine arsenic levels among endemic residents, and they developed novel dietary practices, such as properly drying, storage, and washing of food. Additionally, the awareness rate of CBBA increased from less than 70 % to over 95 %. Finally, the prevalence of CBBA has decreased to 0.153 % investigated by a census involving 2.076 million endemic residents in 2019. In summary, CBBA in northwest China has been successfully controlled through banning on high-arsenic coal, introducing improved cook-stoves, and providing health education.

Pathogenic Leptospira Detection in Environmental Contaminant Water Sources by Highly Performance Antibody Absorption Polystyrene Agglutinating Particles

AbstractLeptospirosis is a re‐emerging bacterial zoonotic disease that affects both humans and animals, with a significantly higher incidence in tropical and sub‐tropical regions. Disease control, epidemiology, and surveillance rely on a One Health approach, as accurate detection can be applied to humans, animals, and the environment. This study represents the first attempt to develop a method for detecting the pathogenic Leptospira santarosai serovar Shermani based on the latex agglutination reaction. The serological activity of the antibody is examined to achieve a high titer of antibody before adsorption onto polystyrene particles. Using a pH medium of 6.8–7.8, total antibody adsorption of up to 3 mg m−2 is achieved. Particle agglutination is observed after incubating the antibody‐adsorbed PS with leptospiral culture for 4 min, revealing a detection limit of 1.7 × 102 leptospires mL−1. Interestingly, the detection limit increased by 1000 times when observing agglutination using spectrophotometer. The test exhibits high specificity with Shermani and shows negligible cross‐agglutination with non‐pathogenic Leptospira and water‐borne bacteria. Agglutination testing in collected water samples from natural sources demonstrates a good correlation with culture technique. This simple and rapid leptospires agglutination detection method can be applied as a screening test in environmental, human, and animal specimens.

A high-throughput, polymerase-targeted RT-PCR for broad detection of mammalian filoviruses.

Filoviruses are some of the most lethal viruses in the modern world, and increasing numbers of filovirus species and genera have been discovered in recent years. Despite the potential severity of filovirus outbreaks in the human population, comparably few sensitive pan-filovirus RT-PCR assays have been described that might facilitate early detection and prevention. Here, we present a new pan-filovirus RT-PCR assay targeting the L polymerase gene for detection of all known mammalian filoviruses. We demonstrate the detection of 10 synthetic filovirus RNA templates with analytical sensitivity ranging from 178 to 3,354 copies/mL, without cross-reactivity on 10 non-filoviral human viral species. We verified assay performance on 10 inactivated filovirus isolates, yielding initial sensitivities of 0.012-44.17 TCID50/mL. We coupled this broadly reactive RT-PCR with a deep sequencing workflow that is amenable to high-throughput pooling to maximize detection and discovery potential. In summary, this pan-filovirus RT-PCR assay targets the most conserved filovirus gene, offers the widest breadth of coverage to date, and may help in the detection and discovery of novel filoviruses.IMPORTANCEFiloviruses remain some of the most mysterious viruses known to the world, with extremely high lethality rates and significant pandemic potential. Yet comparably few filovirus species and genera have been discovered to date and questions surround the definitive host species for zoonotic infections. Here, we describe a novel broadly reactive RT-PCR assay targeting the conserved L polymerase gene for high-throughput screening for filoviruses in a variety of clinical and environmental specimens. We demonstrate the assay can detect all known mammalian filoviruses and determine the sensitivity and specificity of the assay on synthetic RNA sequences, inactivated filovirus isolates, and non-filoviral species.

A study on the effect of mixture constituents on washout resistance, mechanical, and transport properties in the context of underwater 3D concrete printing

Underwater layered concrete depositions, such as those obtained using 3D printing, demonstrate washout resistance, which influences layer stability, transport properties, and inter-layer mechanical strength, thus impacting its final properties. This work first focuses on understanding the compositional effect of 3D printable mortars on their washout resistance. Conventional methods for assessing washout resistance of underwater concrete are ill-suited to 3D printable materials due to different mix designs and material deposition techniques. To address this, a new protocol considering layered deposition during 3D printing was developed to evaluate the washout resistance. Interrogation of the pore structure of the printed specimens (in air and underwater environment) via water absorption and sorptivity test further establishes the influence of washout on water transport properties. The study also investigates the impact of hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA) fiber dosages on mechanical properties, including compressive strength, interlayer split tensile strength, and flexural strength. Results indicate that HPMC addition significantly improves the washout resistance, whereas PVA fibers have detrimental effect. However, optimizing the PVA fiber dosage enhances both mechanical and water transport properties of underwater printed specimen via permeable void and capillary pore structure refinement.

Unique algorithm for the evaluation of embryo photon emission and viability

Living cells have spontaneous ultraweak photon emission derived from metabolic reactions associated with physiological conditions. The ORCA-Quest CMOS camera (Hamamatsu Photonics, Japan) is a highly sensitive and essential tool for photon detection; its use with a microscope incubator (Olympus) enables the detection of photons emitted by embryos with the exclusion of harmful visible light. With the application of the second law of thermodynamics, the low-entropy energy absorbed and used by embryos can be distinguished from the higher-entropy energy released and detectable in their environment. To evaluate higher-entropy energy data from embryos, we developed a unique algorithm for the calculation of the entropy-weighted spectral fractal dimension, which demonstrates the self-similar structure of the energy (photons) released by embryos. Analyses based on this structure enabled the distinction of living and degenerated mouse embryos, and of frozen and fresh embryos and the background. This novel detection of ultra-weak photon emission from mouse embryos can provide the basis for the development of a photon emission embryo control system. The ultraweak photon emission fingerprints of embryos may be used for the selection of viable specimens in an ideal dark environment.

Experimental Study on the Strength Deterioration and Mechanism of Stabilized River Silt Reinforced with Cement and Alginate Fibers.

River silt deposited by water in coastal areas is unsuitable for engineering construction. Thus, the in situ stabilization treatment of river silt as the bearing layer has been an important research area in geotechnical engineering. The strength degradation behavior and mechanism of stabilized river silt reinforced with cement and alginate fibers (AFCS) in different engineering environments are crucial for engineering applications. Therefore, freeze-thaw (F-T) cycle tests, wetting-drying (W-D) cycle tests, water immersion tests and seawater erosion tests were conducted to explore the strength attenuation of stabilized river silt reinforced with the same cement content (9% by wet weight) and different fiber contents (0%, 0.3%, 0.6% and 0.9% by weight of wet soil) and fiber lengths (3 mm, 6 mm and 9 mm). The reinforcement and damage mechanism of AFCS was analyzed by scanning electron microscopy (SEM) imaging. The results indicate that the strength of AFCS was improved from 84% to 180% at 15 F-T cycle tests, and the strength of AFCS was improved by 26% and 40% at 30 W-D cycles, which showed better stability and excellent characteristics owing to the hygroscopic characteristics of alginate fiber arousing the release of calcium and magnesium ions within the alginate. Also, the strength attenuation of AFCS was reduced with the increase in the length and content of alginate fibers. Further, the strength of specimens in the freshwater environment was higher than that in the seawater environment at the same fiber content, and the softening coefficient of AFCS in the freshwater environment was above 0.85, indicating that the AFCS had good water stability. The optimal fiber content was found to be 0.6% based on the unconfined compressive strength (UCS) reduction in specimens cured in seawater and a freshwater environment. And the strength of AFCS was improved by about 10% compared with that of cement-stabilized soil (CS) in a seawater environment. A stable spatial network structure inside the soil was formed, in which the reinforcing effect of fibers was affected by mechanical connection, friction and interfacial bonding. However, noticeable cracks developed in the immersed and F-T specimens. These microscopic characteristics contributed to decreased mechanical properties for AFCS. The results of this research provide a reference for the engineering application of AFCS.

A Recyclable Luminescent MOF Sensor for On-Site Detection of Insecticide Dinotefuran and Anti-Parkinson's Drug Entacapone in Various Environmental and Biological Specimens.

The monitoring and precise determination of pesticides and pharmaceutical drugs and their residues have become increasingly important in the field of food safety and water contamination issues. Herein, a fluorescent aluminium MOF-based sensor (1) was developed for the selective recognition of neonicotinoid insecticide dinotefuran and anti-Parkinson's drug entacapone. Guest-free MOF 1' exhibited ultra-fast response (<5 s) and ultra-low detection limits of 2.3 and 7.6 nM for dinotefuran and entacapone, which are lower than the previously reported MOF-based sensors. In the presence of other competitive analytes, great selectivity was achieved towards both analytes. The probe was recyclable up to five cycles. The sensing ability was explored towards entacapone in human serum, urine and dinotefuran in real soil, rice, honey samples, different fruits, vegetables, real water specimens and a wide range of pH media. A low-cost, handy MOF-based polymer thin-film composite (1'@PVDF-PVP) was developed for the on-site detection of dinotefuran and entacapone. Mechanistic studies involving analytical techniques and theoretical calculations suggested that FRET and PET are the probable reasons for entacapone sensing whereas IFE is responsible for dinotefuran detection. The entire work presents a low cost, multi-use photoluminescent sensor of entacapone and dinotefuran to address the environmental pollution.