Adenosine Triphosphate Measurements Research Articles

Context-dependent modification of PFKFB3 in hematopoietic stem cells promotes anaerobic glycolysis and ensures stress hematopoiesis.

Metabolic pathways are plastic and rapidly change in response to stress or perturbation. Current metabolic profiling techniques require lysis of many cells, complicating the tracking of metabolic changes over time after stress in rare cells such as hematopoietic stem cells (HSCs). Here, we aimed to identify the key metabolic enzymes that define differences in glycolytic metabolism between steady-state and stress conditions in murine HSCs and elucidate their regulatory mechanisms. Through quantitative 13C metabolic flux analysis of glucose metabolism using high-sensitivity glucose tracing and mathematical modeling, we found that HSCs activate the glycolytic rate-limiting enzyme phosphofructokinase (PFK) during proliferation and oxidative phosphorylation (OXPHOS) inhibition. Real-time measurement of ATP levels in single HSCs demonstrated that proliferative stress or OXPHOS inhibition led to accelerated glycolysis via increased activity of PFKFB3, the enzyme regulating an allosteric PFK activator, within seconds to meet ATP requirements. Furthermore, varying stresses differentially activated PFKFB3 via PRMT1-dependent methylation during proliferative stress and via AMPK-dependent phosphorylation during OXPHOS inhibition. Overexpression of Pfkfb3 induced HSC proliferation and promoted differentiated cell production, whereas inhibition or loss of Pfkfb3 suppressed them. This study reveals the flexible and multilayered regulation of HSC glycolytic metabolism to sustain hematopoiesis under stress and provides techniques to better understand the physiological metabolism of rare hematopoietic cells.

Using total adenosine triphosphate (tATP) measurements for cyanobacterial bloom monitoring and response assessment during algaecide treatments

Total adenosine triphosphate (tATP) was investigated for its potential as a rapid indicator of cyanobacterial growth and algaecide effectiveness. tATP and other common bloom monitoring parameters were measured over the growth cycles of cyanobacteria and green algae in laboratory cultures and examined at a drinking water source during an active bloom. Strong correlations (R2>0.78) were observed between tATP and chlorophyll-a in cyanobacteria cultures. tATP offered greater sensitivity by increasing two orders of magnitude approximately 7 d before changes in chlorophyll-a or optical density were observed in Lyngbya sp. and Dolichospermum sp. cultures. Increases in tATP per cell coincided with the onset of exponential growth phases in lab cultures and increase in cell abundance in field samples, suggesting that ATP/cell is a sensitive indicator that may be used to identify the development of blooms. Bench-scale trials using samples harvested during a bloom showed that tATP exhibited a clear dose-response during copper sulfate (CuSO4) and hydrogen peroxide (H2O2) treatment compared to chlorophyll-a and cell counts, indicating that cellular production and storage of ATP decreases even when live and dead cells cannot be distinguished. During Copper (Cu) algaecide application at a reservoir used as a drinking water source, tATP and cell counts decreased following initial algaecide application; however, the bloom rebounded within 10 d showing that the Cu algaecide only has limited effectiveness. In this case, tATP was a sensitive indicator to bloom rebounding after algaecide treatments and correlated positively with cell counts (R2=0.7). These results support the use of tATP as a valuable complementary bloom monitoring tool for drinking water utilities to implement during the monitoring and treatment of cyanobacterial blooms.

A simple assay for inhibitors of mycobacterial oxidative phosphorylation

Oxidative phosphorylation, the combined activities of the electron transport chain (ETC) and adenosine triphosphate (ATP) synthase, has emerged as a valuable target for antibiotics to treat infection with Mycobacterium tuberculosis and related pathogens. In oxidative phosphorylation, the ETC establishes a transmembrane electrochemical proton gradient that powers ATP synthesis. Monitoring oxidative phosphorylation with luciferase-based detection of ATP synthesis or measurement of oxygen consumption can be technically challenging and expensive. These limitations reduce the utility of these methods for characterization of mycobacterial oxidative phosphorylation inhibitors. Here we show that fluorescence-based measurement of acidification of inverted membrane vesicles (IMVs) can detect and distinguish between inhibition of the ETC, inhibition of ATP synthase, and non-specific membrane uncoupling. In this assay, IMVs from M. smegmatis are acidified either through the activity of the ETC or ATP synthase, the latter modified genetically to allow it to serve as an ATP-driven proton pump. Acidification is monitored by fluorescence from 9-amino-6-chloro-2-methoxyacridine, which accumulates and quenches in acidified IMVs. Non-specific membrane uncouplers prevent both succinate- and ATP-driven IMV acidification. In contrast, the ETC Complex III2IV2 inhibitor telacebec (Q203) prevents succinate-driven acidification but not ATP-driven acidification and the ATP synthase inhibitor bedaquiline prevents ATP-driven acidification but not succinate-driven acidification. We use the assay to show that, as proposed previously, lansoprazole sulfide is an inhibitor of Complex III2IV2 while thioridazine uncouples the mycobacterial membrane non-specifically. Overall, the assay is simple, low cost, and scalable, which will make it useful for identifying and characterizing new mycobacterial oxidative phosphorylation inhibitors.

Homogeneous luminescent quantitation of cellular guanosine and adenosine triphosphates (GTP and ATP) using QT-LucGTP&ATP assay

Guanosine triphosphate (GTP) and adenosine triphosphate (ATP) are essential nucleic acid building blocks and serve as energy molecules for a wide range of cellular reactions. Cellular GTP concentration fluctuates independently of ATP and is significantly elevated in numerous cancers, contributing to malignancy. Quantitative measurement of ATP and GTP has become increasingly important to elucidate how concentration changes regulate cell function. Liquid chromatography–coupled mass spectrometry (LC–MS) and capillary electrophoresis-coupled MS (CE–MS) are powerful methods widely used for the identification and quantification of biological metabolites. However, these methods have limitations related to specialized instrumentation and expertise, low throughput, and high costs. Here, we introduce a novel quantitative method for GTP concentration monitoring (GTP-quenching resonance energy transfer (QRET)) in homogenous cellular extracts. CE–MS analysis along with pharmacological control of cellular GTP levels shows that GTP-QRET possesses high dynamic range and accuracy. Furthermore, we combined GTP-QRET with luciferase-based ATP detection, leading to a new technology, termed QT-LucGTP&ATP, enabling high-throughput compatible dual monitoring of cellular GTP and ATP in a homogenous fashion. Collectively, GTP-QRET and QT-LucGTP&ATP offer a unique, high-throughput opportunity to explore cellular energy metabolism, serving as a powerful platform for the development of novel therapeutics and extending its usability across a range of disciplines.Graphical

Fluorescence Imaging of Nanoparticle Uptake into Liquid-Liquid Phase-Separated Droplets.

Liquid-liquid phase separation (LLPS) in living cells has received considerable attention in the biomedical research field. This study is the first to report nanoparticle (NP) uptake into LLPS droplets. Fluorescent dye, Nile red loaded polystyrene NPs (NR-PSt NPs) uptake into model LLPS droplets consisting of adenosine triphosphate (ATP) and poly-L-lysine (PLL) was visualized using fluorescence imaging. Fluorescence imaging showed that the LLPS droplets had a quick NP uptake behavior. Furthermore, temperature changes (4-37 °C) significantly affected the NP uptake behavior of the LLPS droplets. Moreover, the NP-incorporated droplets displayed high stability under strong ionic strength conditions (1 M NaCl). ATP measurements displayed that ATP was released from the NP-incorporated droplets, indicating that the weakly negatively charged ATP molecules and strongly negatively charged NPs were exchanged, which resulted in the high stability of the LLPS droplets. These fundamental findings will contribute to the LLPS studies using various NPs.

Understanding the risk of using herbicides for tree root removal into wastewater treatment plant performance

Adding herbicides to sewer lines, a common practice for controlling root intrusion in sewer pipes, may adversely impact downstream wastewater treatment by inhibiting nitrification and denitrification performance. This study investigated the effects of herbicides, namely diquat, triclopyr, and 2-methyl-4-chlorophenoxyacetic acid (MCPA)-dicamba, on these processes. Various parameters were monitored, including oxygen uptake rate (OUR), nutrients (NH3–N, TP, NO3–N, and NO2–N), chemical oxygen demand (COD), and herbicide concentrations. It was found that nitrification was not affected by OUR in the presence of each herbicide at various concentrations (1, 10, and 100 mg L−1). Additionally, MCPA-dicamba at various concentrations demonstrated minimal inhibition in the nitrification process compared to diquat and triclopyr. COD consumption was not affected by the presence of these herbicides. However, triclopyr significantly inhibited NO3–N formation in the denitrification process at various concentrations. Similar to nitrification process, both COD consumption and herbicide reduction concentration were not affected by the presence of herbicides during the denitrification process. Adenosine triphosphate measurements showed minimal impact on nitrification and denitrification processes when herbicides were present in the solution up to a concentration of 10 mg L−1. Tree root kill efficiency experiments were performed on Acacia melanoxylon. Considering the performance on nitrification and denitrification process, diquat emerged as the best herbicide option (concentration of 10 mg L−1), with a 91.24% root kill efficiency.

Overcoming Debye length limitations: Three-dimensional wrinkled graphene field-effect transistor for ultra-sensitive adenosine triphosphate detection.

The online version contains supplementary material available at 10.1007/s11467-023-1281-7 and https://journal.hep.com.cn/fop/EN/10.1007/s11467-023-1281-7.

Evidence for inefficient contraction and abnormal mitochondrial activity in sarcopenia using magnetic resonance spectroscopy.

Mitochondrial dysfunction has been implicated in sarcopenia. 31 P magnetic resonance spectroscopy (MRS) enables non-invasive measurement of adenosine triphosphate (ATP) synthesis rates to probe mitochondrial function. Here, we assessed muscle energetics in older sarcopenic and non-sarcopenic men and compared with muscle biopsy-derived markers of mitochondrial function. Twenty Chinese men with sarcopenia (SARC, age=73.1±4.1years) and 19 healthy aged and sex-matched controls (CON, age=70.3±4.2years) underwent assessment of strength, physical performance, and magnetic resonance imaging. Concentrations of phosphocreatine (PCr), ATP and inorganic phosphate (Pi) as well as muscle pH were measured at rest and during an interleaved rest-exercise protocol to probe muscle mitochondrial function. Results were compared to biopsy-derived mitochondrial complex activity and expression to understand underlying metabolic perturbations. Despite matched muscle contractile power (strength/cross-sectional area), the ATP contractile cost was higher in SARC compared with CON (low-intensity exercise: 1.06±0.59 vs. 0.57±0.22, moderate: 0.93±0.43 vs. 0.58±0.68, high: 0.70±0.57 vs. 0.43±0.51mmolL-1 min-1 bar-1 cm-2 , P=0.003, <0.0001 and <0.0001, respectively). Post-exercise mitochondrial oxidative synthesis rates (a marker of mitochondrial function) tended to be longer in SARC but did not reach significance (17.3±6.4 vs. 14.6±6.5mmolL-1 min-1 , P=0.2). However, relative increases in end-exercise ADP in SARC (31.8±9.9 vs. 24.0±7.3mmolL-1 , P=0.008) may have been a compensatory mechanism. Mitochondrial complex activity was found to be associated with exercise-induced drops in PCr [citrate synthetase activity (CS), Spearman correlation rho=-0.42, P=0.03] and end-exercise ADP (complex III, rho=-0.52, P=0.01; CS rho=-0.45, P=0.02; SDH rho=-0.45, P=0.03), with CS also being strongly associated with the PCr recovery rate following low intensity exercise (rho=-0.47, P=0.02), and the cost of contraction at high intensity (rho=-0.54, P=0.02). Interestingly, at high intensity, the fractional contribution of oxidative phosphorylation to exercise was correlated with activity in complex II (rho=0.5, P=0.03), CS (rho=0.47, P=0.02) and SDH (rho=0.46, P=0.03), linking increased mitochondrial complex activity with increased ability to generate energy through oxidative pathways. This study used 31 P MRS to assess ATP utilization and resynthesis in sarcopenic muscle and demonstrated abnormal increases in the energy cost during exercise and perturbed mitochondrial energetics in recovery. Associations between mitochondrial complex activity and the fractional contribution to energy requirement during exercise indicate increased ability to generate energy oxidatively in those with better mitochondrial complex activity.

Pore Size Tunable Trypsin@ZIF-90 and Hydrogel Integrated Lateral Flow Point-of-Care Platform for ATP Detection

The cost-effective, convenient, visible, and equipment-free determination of biomarkers is always the priority development concern of disease diagnosis. The paper-based signal output strategy permits output visual signals without instruments and is regarded as a promising approach with simple operation and low cost. Herein, by varying the addition amount of trypsin, we pioneered a novel enzyme mineralization strategy to construct trypsin@ZIF-90 with tunable porosity properties and catalytic activity. The successful synthesis of trypsin@ZIF-90, which is tagged with T1, T3,... (Tx, x is the addition amount of trypsin. Unit: mg), demonstrated the feasibility of this strategy. By serving the constructed trypsin@ZIF-90-T1 as the target recognition module, and a new designed hydrogel-integrated pH indicator strip as the signal reporter, a point-of-care test (POCT) platform was developed for convenient and equipment-free measurement of adenosine triphosphate (ATP). The enzymatic activity measurement of trypsin@ZIF-90 and concurrently the quantitative analysis of ATP can be favorably realized by simple counting the flow distance and coverage area of water released during the reaction on a pH indicator strip. As a result, this portable platform can enable rapid detection of ATP in the linear range of 20-1500 μM and possesses favorable sensitivity, selectivity, and applicability. Thus, the constructions of tunable frameworks and paper-based POCT are of outstanding significance in the fields of porous metal-organic framework synthesis, enzyme mineralization, and rapid detection for medical diagnostics and environmental monitoring applications.

Long non-coding RNA DANCR alleviates acute myocardial infarction damage via regulating microRNA-509-5p/KLF transcription factor 13 pathway.

Acute myocardial infarction (AMI) is the most important cause of death among cardiovascular diseases. Long noncoding RNAs (lncRNAs) have been widely implicated in the regulation of AMI progression. Discrimination antagonizing nonprotein coding RNA (DANCR) alleviated hypoxia-caused cardiomyocyte damages, and the underlying mechanisms remain unclear. Here, we investigated the function and mechanism of DANCR in hypoxia-induced cardiomyocytes and AMI model by enzyme-linked immunosorbent assay, reactive oxygen species and adenosine triphosphate measurement, and mitochondrial activity determination. Additionally, luciferase reporter assay, immunoblotting, and qRT-PCR were performed to validate the interactions between DANCR/miR-509-5p and miR-509-5p/Kruppel-like factor 13 (KLF13). The role of DANCR was also verified in AMI model by overexpression. Our results showed that DANCR expression was significantly downregulated in hypoxia-induced cardiomyocytes or AMI model. Overexpression of DANCR significantly alleviated mitochondrial damages, reduced inflammation, and improved cardiac function in the AMI model. Furthermore, we demonstrated that miR-509-5p/KLF13 axis mediated the protective effect of DANCR. The current study highlighted the critical role of DANCR in alleviating AMI progression through targeting the miR-509-5p/KLF13 signaling axis, suggesting that DANCR may serve as a potential diagnostic marker or therapeutic target for AMI.

SG-APSIC1091: Assessment of compliance to cleaning of computers by healthcare workers (HCWs) using adenosine triphosphate (ATP) measurement

Objectives: HCWs are recommended to wipe the computers with alcohol wipes before clinical use. Compliance assessment by direct observation is resource intensive. We used ATP measurement as a surrogate to assess the compliance to preutilization cleaning of computers. Methods: We conducted a pilot study to determine the median relative light unit (RLU) value reflective of preutilization cleaning of the computers. We identified values of &lt;250, 250–500, and &gt;500 RLU to reflect cleaned, probably cleaned, and not cleaned computers, respectively. Subsequently, we conducted a cross-sectional study of the computers in the inpatient wards in Tan Tock Seng Hospital and National Centre for Infectious Diseases. Using 3M Clean-Trace ATP swabs, we tested 5 computers in each ward: 2 computers on wheels, 2 from the nursing station, and 1 at the patients’ room entrance. All analyses were conducted using STATA version 15 software. Results: Between October 4 and 10, 2021, we collected 219 samples from 219 computers. Among them, 44 (20.1%) were cleaned, 49 (22.4%) were probably cleaned, and 126 (57.5%) computers were not cleaned. Higher compliance to computer cleaning was observed in COVID-19 wards [85 ATP samples; cleaned, 37 (43.5%); probably cleaned, 26 (30.6%); not cleaned, 22 (25.9%)] compared with non–COVID-19 wards [134 ATP samples; cleaned, 7 (5.2%); probably cleaned, 23 (17.2%); not cleaned, 104 (77.6%)] (P &lt; .01). No significant difference was observed in compliance with cleaning computers between the ICU [30 ATP samples; cleaned, 7 (23.3%); probably cleaned, 4 (13.3%); not cleaned, 19 (63.3%)] and general wards [189 ATP samples; cleaned, 37 (19.6%); probably cleaned, 45 (23.8%); not cleaned, 107 (56.6%)] (P = .47). Conclusions: ATP swab tests can be used as a surrogate marker to assess compliance to pre-utilization cleaning of computers. Enhanced awareness of environmental hygiene may explain the higher compliance to computer cleaning observed in COVID-19 wards.

SG-APSIC1024: The importance of the washing evaluation of flusher disinfector in the medical site: Visual evaluation with the ISO standardized test soil and adenosine triphosphate level

Objectives: We examined the washing evaluation method of the flusher disinfector installed in the medical site by visual evaluation using an ISO test soil and adenosine triphosphate (ATP) measurement. Methods: The test soil shown in ISO15883-5 was applied to the bedpan using 2 methods (N = 10) and was then visually evaluated using a 4-step scale. The ATP value on the surface of the bedpan corresponding to each scale was measured, and the correlation with the visual scale was confirmed. In addition, a visual evaluation was performed using a different flusher disinfector and bedpan (N = 3). Results: In the visual evaluation, when the test soil was applied to the entire surface of the bedpan, it remained in the parts where the water flow was hard to hit. When the test soil was applied to the surface of the bedpan except the lid, no soil remained. The 4-step visual evaluation scale and the logarithm of ATP value showed a positive correlation. In visual evaluations with different flusher disinfector and bedpan combinations, the residual soil patterns tended to be different. Some bedpans showed washing failure related to improper design. Conclusions: Poor cleaning of flusher disinfectors may occur when the amount of water used is insufficient or when the bedpan is significantly contaminated. It is important to carry out flusher disinfector washing evaluation at medical sites to evaluate the function of flusher disinfectors. An appropriate program must be utilized for staff education and appropriate management. Because flusher disinfectors and bedpans differ, flusher disinfector cleaning evaluations should be carried out at all facilities.

SG-APSIC1045: A quantitative assessment of ATP bioluminescence on dental instruments reprocessed by automated washer-disinfector and ultrasonic machine

Objectives: Dental instruments are contaminated by blood and saliva during dental procedures. To prevent cross infection, all contaminants should be removed from the surfaces of instruments. Inadequate cleaning can hinder disinfection and sterilization process. To compare the cleaning efficacy of an automated washer–disinfector versus an ultrasonic machine on dental instruments, adenosine triphosphate (ATP) measurements were compared. Methods: From National University Polyclinic Bukit Panjang Dental Services, we collected 2 loads of 40 dental instruments previously used in dental treatments: extraction forceps, high-volume suction tips, Coupland elevators, matrix band holders, and ultrasonic scaler tips. At the point of use, gross soil was wiped from instrument surfaces with water. Each instrument was swabbed after cleaning either using a washer–disinfector or an ultrasonic machine. The relative light units (RLU) on the luminometer indicated the amount of ATP contaminants and residue bioburden present on the instruments. Results: The mean RLU values across all instruments in the washer–disinfector group was 2.5 times lower than the mean value of the instruments in the ultrasonic group (35.4 vs 89.9 RLU). This difference was statistically significant for all instrument groups except for the high-volume suction tips. The Mann-Whitney U test indicated that the RLU in the ultrasonic group was higher than the RLU for the washer–disinfector group for extraction forceps (P &lt; .001), ultrasonic scaler tips (P &lt; .023), and matrix bands (P &lt; .006). A t test indicated the same relationship for Coupland elevators (P &lt; .005). Conclusions: The mean RLU values for both cleaning methods were lower than the manufacturer’s benchmark (RLU ≤ 150), suggesting that both methods can achieve effective cleaning. However, cleaning using an automated washer–disinfector is significantly more effective than an ultrasonic machine for nonlumen instruments. The effectiveness of cleaning using ultrasonic machine varied greatly among different types of instruments with different design complexities.

The critical adenosine triphosphate (ATP) concentration in treated ballast water

Measuring Adenosine triphosphate (ATP) provides a proxy to check compliance with IMO's ballast water D-2 standard: <10 cells mL−1 in the 10–50 μm size class. Measured with standard boiling techniques the ATP concentration in aquatic eukaryotic microorganisms is 0.6 mol m−3. Model calculations with 10–50 μm spherical organisms show their ATP content is 0.2 to 20 pg cell−1, in line with several cell lysis data. However, at 10 cells mL−1, these ATP contents lead to a maximum of only 2 to 200 pg ATP mL−1, at least 7.5× below a D-2 test kit 1500 pg ATP mL−1 upper limit. Different cell shape and ATP extraction scenarios to reach 1500 pg ATP mL−1 are discussed but remain improbable. Because cell lysis data are inconclusive, and a novel phosphoric acid-benzalkonium chloride method indicates up to 3× higher ATP concentrations, an independent test kit validation and a comparison of all three techniques are recommended.

The bactericidal and biofilm removal effect of super reducing water on Streptococcus mutans in three types of orthodontic brackets.

To investigate the bactericidal and biofilm removal effect of super reducing water (SRW) on Streptococcus mutans (S. mutans) adhered to orthodontic brackets, in vitro. Three types of brackets were bonded to aluminum disks. After the formation of S. mutans biofilms on the surfaces, the brackets were divided into three groups (n = 44 each) based on their exposure to SRW: group 1, no treatment; group 2, treated for 5 min; and group 3, treated for 10 min. Total viable counts, adenosine triphosphate measurements, crystal violet assay, and scanning electron microscopy were used to evaluate the effect of SRW. The bacterial counts in groups 2 and 3 were significantly lower than those in group 1 (P < 0.001); however, no significant differences were observed between groups 2 and 3. Marked decreases in the number of bacterial colonies and extent of biofilm formation were observed in groups 2 and 3 compared to group 1. No significant differences in the number of bacterial colonies and amount of biofilm were observed among the three types of brackets in each group. These findings indicate the bactericidal and biofilm removal effect of SRW treatment on S. mutans adhered to orthodontic brackets.

In Vitro Photodynamic Treatment Modality for A375 Melanoma Cell Line Using a Sulphonated Aluminum Phthalocyanine Chloride-Photosensitizer-Gold Nanoparticle Conjugate.

Metastatic melanoma cancer stem cells are subpopulations that have been identified and linked to tumor progression, immunoevasive behavior, drug resistance, and metastasis, leading to a poor prognosis. Photodynamic therapy (PDT) is an approach to eradicate cancer through a photochemical process which directly generates reactive oxygen species (ROS). This study investigated the impact of PDT using an aluminum phthalocyanine gold nanoparticle (AlPcS4Cl-AuNP) conjugate for targeting melanoma stem cells. The isolated stem cells were irradiated at 673.2 nm with a radiant exposure of 5 J/cm2. Post-irradiation signs of cell death were determined using microscopy and biochemical assays. A possible enhanced effect of ROS in inducing cell death could be seen when AlPcS4Cl was conjugated to AuNPs. Nanoparticles as carriers promote the efficient cellular uptake of photosensitizers, enhancing organelle accumulation and the targeted therapy of cancerous cells. A biochemical assay revealed significant post-irradiation signs of cell death. The measurement of adenosine triphosphate (ATP) content revealed a decrease in cell proliferation. The study suggested an approach directed at expanding the knowledge on PDT to improve cancer treatment. Understanding the cell death mechanism through which ROS influence cancer stem cells (CSCs) is, therefore, useful for improving PDT efficiency and preventing tumor recurrence and metastasis.

Non-ohmic electrical fringe field selective to biofilm suitable for addressing biofouling in wastewater treatment

The non-ohmic electrical fringe field has been shown to be a viable approach for addressing biofouling in wastewater treatment. Existing attached growth systems require periodic mechanical- or chemical-based maintenance or part replacement to regulate excessive biofilm formation. The proposed electrical approach uses a non-ohmic fringe field at a low voltage of 10 V and a low frequency of 100 kHz, where bacterial biofilm growth is noticeably reduced. The fringe field was generated by insulated interdigitated electrodes embedded below the surface on which the biofilm grew. Electric field simulation showed field strength of 15.2 and 12.3 V/cm at 0.05 and 1 mm from the surface, respectively, which are sufficient to reduce biofilm growth. As the biofilm grows, the fringe field passing through it becomes denser (hence, higher field strength) owing to the difference in relative permittivity. It selectively targeted biofilms in water. The optical density measurements showed that the presence of fringe field was able to reduce the biofilm by ∼10.1 % as compared to the control. Adenosine triphosphate measurements suggested that the effect of fringe field on bacterial viability was even more pronounced at ∼20.6 % reduction. This is an efficient approach with no moving parts suitable for uninterrupted biofilm growth regulation in wastewater treatment.

Ketogenic diet modulates cardiac metabolic dysregulation in streptozocin-induced diabetic rats

The ketogenic diet (KD) might improve cardiac function in diabetic cardiomyopathy, but the mechanisms remain unclear. This study investigated the effects of KD on myocardial fatty acid (FA), glucose, and ketone metabolism in diabetic cardiomyopathy. Echocardiograms, biochemistry, and micro-positron emission tomography were performed to evaluate cardiac function and glucose uptake in control rats and streptozotocin-induced diabetes mellitus (DM) rats with normal diet (ND) or KD for 6 weeks. Histopathology, adenosine triphosphate measurement, and Western blot were performed in the ventricular myocytes to analyze fibrosis, FA, ketone body, and glucose utilization. The ND-fed DM rats exhibited impaired left ventricular systolic function and increased chamber dilatation, whereas control and KD-fed DM rats did not. The KD reduced myocardial fibrosis and apoptosis in the DM rats. Myocardial glucose uptake in the micro-positron emission tomography was similar between ND-fed DM rats and KD-fed DM rats and was substantially lower than the control rats. Compared with the control rats, ND-fed DM rats had increased phosphorylation of acetyl CoA carboxylase and higher expressions of CD-36, carnitine palmitoyltransferase-1β, tumor necrosis factor-α, interleukin-1β, interleukin6, PERK, and e-IF2α as well as more myocardial fibrosis and apoptosis (assessed by Bcl-2, BAX, and caspase-3 expression); these increases were attenuated in the KD-fed DM rats. Moreover, ND-fed DM rats had significantly lower myocardial adenosine triphosphate, BHB, and OXCT1 levels than the control and KD-fed DM rats. The KD may improve the condition of diabetic cardiomyopathy by suppressing FA metabolism, increasing ketone utilization, and decreasing endoplasmic reticulum stress and inflammation.

Nickel nanoparticles exert cytotoxic effects on trophoblast HTR-8/SVneo cells possibly via Nrf2/MAPK/caspase 3 pathway

Nickel nanoparticles are widely used in the industry and may affect the reproductive system. The potential molecular mechanism of exposing the first-trimester trophoblast cell line (HTR-8/SVneo) to nickel nanoparticles remains unclear. Hence, the aim of this study was to investigate the in vitro cytotoxicity of Ni NPs on HTR-8/SVneo cells. HTR-8/SVneo cells were subjected to various concentrations (0, 2.5, 5, 7.5, 10, and 12.5 μg/cm2) of Ni NPs. The toxicity of the Ni NPs was evaluated in HTR-8/SVneo cells by measuring cell viability. The underlying mechanism of nickel nanoparticles toxicity to HTR-8/SVneo cells was determined by measuring the content of intracellular reactive oxygen species, mitochondrial membrane potential, and the rate of cell apoptosis and cell cycle, by measuring adenosine triphosphate levels, intracellular lipid peroxidation malondialdehyde, total superoxide dismutase, and CuZn/Mn-SOD activities, and by determining proteins related to Nrf2, MAPK, and Cytochrome c. Our results showed that the nickel nanoparticles treatment reduced the viability of HTR-8/SVneo cells, while it increased their oxidative stress and lowered their mitochondrial respiratory capacity. Additionally, the nickel nanoparticles treatment induced cell S-phase arrest and apoptosis. These molecular events may be linked to the oxidative stress-Nrf2 pathway/MAPK/Caspase 3 cascade. Thus, nickel nanoparticles exert cytotoxic effects on HTR-8/SVneo cells, which could affect the function of the placenta in human.

Arch-type feed spacer with wide passage node design for spiral-wound membrane filtration with reduced energy cost

A novel feed spacer for spiral-wound membrane modules is proposed. Based upon a continuous arch-type streamline frame two feed spacers with different node designs were constructed. In the first, Arch-Hole, two elliptic cylinders form a node zone with a passage. The other, named Arch, has a solid node. Their hydrodynamics, fouling and filtration performance were compared with a commercial design. This was a classic net-type spacer with nodes of relatively substantial size. All three were manufactured using 3D printing. Computational fluid dynamics simulation showed that the Arch-Hole design gives a more uniform velocity distribution with fewer dead zones. Subsequent evaluation of this design indicated less foulant accumulation as confirmed by optical coherence tomography and the evolution of channel pressure drop. Measured adenosine triphosphate and total organic carbon values for the module with this spacer were substantially lower than the corresponding values associated with the commercial design. Crucially with the Arch-Hole design, flux values remained higher than for the other two designs. Thus use of this spacer would minimize both capital and operational costs. Compared to the commercial one, use of the Arch-Hole design would reduce the energy cost of filtration significantly beyond the 69 % found for the application considered herein.