Cervical Cancer Screening via Visual Inspection With Acetic Acid and Lugol Iodine for Triage of HPV-Positive Women.

Importance: Limited evidence supports the performance of human papillomavirus (HPV) DNA testing as a primary screening method, followed by triage with visual inspection with acetic acid, in areas with limited health care resources, as suggested by the 2021 World Health Organization guidelines. Objective: To evaluate the performance of visual inspection with acetic acid and Lugol iodine as a triage method for detecting cervical precancerous lesions among HPV-positive women in 1 visit. Design, Setting, and Participants: This cohort study examined the implementation of a government-led cervical cancer screening program conducted from January 1, 2016, to December 31, 2020, in Ordos City, China. Female residents, aged 35 to 64 years, who understood the screening procedures and voluntarily participated were included in the study. Women were excluded if they reported never having had sexual intercourse, were pregnant, had a hysterectomy, or had ever undergone treatment for cervical lesions. Statistical analysis was conducted from December 2022 to December 2023. Exposures: The program used the careHPV DNA assay as the primary screening method, and immediate triage was performed by visual inspection if HPV screening results were positive, with a 5-year screening interval. A colposcopy was performed for the women who had suspected cancer on visual inspection results or who were HPV positive and had abnormal visual inspection results, all in 1 visit. Main Outcomes and Measures: The rate of compliance with colposcopy and the detection rate of cervical intraepithelial neoplasia grade 2 or higher (CIN2+). Results: The study included 187 863 women (median age, 46 years [IQR, 40-52 years]) who participated in the program and had valid HPV test results. The overall prevalence of HPV positivity was 12.8% (24 070 of 187 863), and the adherence to triage with visual inspection among HPV-positive women was 93.9% (22 592 of 24 070). Among HPV-positive women, the rate of compliance with colposcopy was 65.6% (2714 of 4137), and the CIN2+ detection rate was 2.8% (643 of 22 592). Conclusions and Relevance: The findings of this cohort study suggest that the implementation of HPV testing, visual inspection, and colposcopy within 1 visit may mitigate losses to follow-up, detect precancerous lesions, and hold significant implications for screening in comparable areas with limited health care resources.

Effects of supplementary Da Dingfeng Zhu therapy on patients with Parkinson's disease of liver-kidney yin deficiency pattern.

BACKGROUND: This study aimed to verify whether the combined use of Da Dingfengzhu and Western medicine in treating Parkinson's disease (PD) can lead to therapeutic efficacy and symptom alleviation, thereby achieving a complementary and synergistic effect. METHODS: In this study, 158 patients were initially enrolled, with 116 eligible patients randomly divided into a control and an observation group. The control group received levodopa/benserazide and pramipexole, while the observation group received Da Dingfengzhu combined with levodopa/benserazide and pramipexole for 12 weeks. Baseline patient characteristics, adverse reactions, and blood samples were collected at baseline and 12 weeks post-treatment. The Unified Parkinson's Disease Rating Scale (UPDRS) was used to assess symptom severity at baseline, four weeks into treatment, and 12 weeks post-treatment. RESULTS: Adverse reactions during treatment were similar in both groups, suggesting that the combined therapy in the observation group did not increase adverse effects. Both groups showed improvements in UPDRS scores, with the observation group displaying more significant symptom alleviation at 4 and 12 weeks. Moreover, the observation group exhibited more pronounced increases in serum neurotrophic factor-3 and dopamine levels and greater reductions in oxidative stress and inflammatory response markers. CONCLUSION: In conclusion, the combination of Da Dingfengzhu with levodopa/benserazide and pramipexole for treating PD shows significant clinical potential and is worthy of broader application.

The Energetic Origins of Pi-Pi Contacts in Proteins.

Accurate potential energy models of proteins must describe the many different types of noncovalent interactions that contribute to a protein's stability and structure. Pi-pi contacts are ubiquitous structural motifs in all proteins, occurring between aromatic and nonaromatic residues and play a nontrivial role in protein folding and in the formation of biomolecular condensates. Guided by a geometric criterion for isolating pi-pi contacts from classical molecular dynamics simulations of proteins, we use quantum mechanical energy decomposition analysis to determine the molecular interactions that stabilize different pi-pi contact motifs. We find that neutral pi-pi interactions in proteins are dominated by Pauli repulsion and London dispersion rather than repulsive quadrupole electrostatics, which is central to the textbook Hunter-Sanders model. This results in a notable lack of variability in the interaction profiles of neutral pi-pi contacts even with extreme changes in the dielectric medium, explaining the prevalence of pi-stacked arrangements in and between proteins. We also find interactions involving pi-containing anions and cations to be extremely malleable, interacting like neutral pi-pi contacts in polar media and like typical ion-pi interactions in nonpolar environments. Like-charged pairs such as arginine-arginine contacts are particularly sensitive to the polarity of their immediate surroundings and exhibit canonical pi-pi stacking behavior only if the interaction is mediated by environmental effects, such as aqueous solvation.

Dynamic changes in lactate levels within the first 24 hours in septic patients as a prognostic indicator: A retrospective cohort study utilizing latent class growth analysis.

Elevated lactate levels are common in sepsis patients. This study aimed to assess the effect of dynamic changes in lactate levels within the first 24 hours following admission on patient prognosis. We extracted data from the Medical Information Mart for Intensive Care (MIMIC)-IV database and classified patients using latent class growth analysis (LCGA). This analysis classified sepsis patients into different groups based on dynamic changes in lactate levels during the initial 24 hours post-admission, dividing this time frame into four periods (0-3 h, 3-6 h, 6-12 h, and 12-24 h). The highest lactate level recorded in each period was then used for patient classification. We subsequently compared the baseline characteristics and outcomes between these different groups. Our study encompassed 7,830 patients, whom LCGA successfully divided into two classes: class 1 (steady lactate class) and class 2 (increasing lactate class). Class 2 demonstrated a worse clinical status at baseline, as indicated by vital signs, disease severity scores, and laboratory results. Importantly, class 2 also had a significantly higher 28-day mortality rate than class 1 (55.6% vs 13.5%, P < 0.001). In conclusion, LCGA effectively categorized sepsis patients into two distinct groups based on their dynamic changes in lactate levels during the first 24 hours post-admission. This methodology has potential utility in clinical practice for managing sepsis patients.

Graphene Hollow Micropatterns via Capillarity-Driven Assembly for Drug Storage and Neural Cell Alignment.

Electrical conductivity, cell-guided surface topology, and drug storage capacity of biomaterials are attractive properties for the repair and regeneration of anisotropic tissues with electrical sensitivity, such as nerves. However, designing and fabricating implantable biomaterials with all these functions remain challenging. Herein, we developed a freestanding graphene substrate with micropatterned surfaces by a simple templating method. Importantly, the raised surface micropatterns had an internal hollow structure. The morphology results showed that the template microgroove width and the graphene nanosheet size were important indicators of the formation of the hollow structures. Through real-time monitoring and theoretical analysis of the formation process, it was found that the main formation mechanism was the delamination and interlayer movement of the graphene nanosheets triggered by the evaporation-induced capillary force. Finally, we achieved the controlled release of loaded microparticles and promoted the orientation of rat dorsal root ganglion neurons by applying an electric field to the hollow micropatterns. This capillarity-induced self-assembly strategy paves the way for the development of high-performance graphene micropatterned films with a hollow structure that have potential for clinical application in the repair of nerve injury.

Advances in In Vitro Models of Neuromuscular Junction: Focusing on Organ-on-a-Chip, Organoids, and Biohybrid Robotics.

The neuromuscular junction (NMJ) is a peripheral synaptic connection between presynaptic motor neurons and postsynaptic skeletal muscle fibers that enables muscle contraction and voluntary motor movement. Many traumatic, neurodegenerative, and neuroimmunological diseases are classically believed to mainly affect either the neuronal or the muscle side of the NMJ, and treatment options are lacking. Recent advances in novel techniques have helped develop in vitro physiological and pathophysiological models of the NMJ as well as enable precise control and evaluation of its functions. This paper reviews the recent developments in in vitro NMJ models with 2D or 3D cultures, from organ-on-a-chip and organoids to biohybrid robotics. Related derivative techniques are introduced for functional analysis of the NMJ, such as the patch-clamp technique, microelectrode arrays, calcium imaging, and stimulus methods, particularly optogenetic-mediated light stimulation, microelectrode-mediated electrical stimulation, and biochemical stimulation. Finally, the applications of the in vitro NMJ models as disease models or for drug screening related to suitable neuromuscular diseases are summarized and their future development trends and challenges are discussed.

Catalytic deAMPylation in AMPylation-inhibitory/assistant forms of FICD protein.

DeAMPylation, as a reversible reaction of AMPylation and mediated by the endoplasmic reticulum-localized enzyme FICD (filamentation induced by cAMP domain protein, also known as HYPE), is an important process in protein posttranslational modifications (PTMs). Elucidating the function and catalytic details of FICD is of vital importance to provide a comprehensive understanding of protein folding homeostasis. However, the detailed deAMPylation mechanism is still unclear. Furthermore, the role of a conserved glutamine (Glu234), that plays an inhibitory role in the AMPylation response, is still an open question in the deAMPylation process. In the present work, the elaborated deAMPylation mechanisms with AMPylation-inhibitory/assistant forms of FICD (wild type and Glu234Ala mutant) were investigated based on the QM(DFT)/MM MD approach. The results revealed that deAMPylation was triggered by proton transfer from protonated histidine (His363) to AMPylated threonine, instead of a nucleophilic attack of water molecules adding to the phosphorus of AMP. The free energy barrier of deAMPylation in the wild type (∼17.3 kcal/mol) is consistent with that in the Glu234Ala mutant of FICD (∼17.1 kcal/mol), suggesting that the alteration of the Glu234 residue does not affect the deAMPylation reaction and indirectly verifying the inducement of deAMPylation in FICD. In the wild type, the proton in the nucleophilic water molecule is transferred to Glu234, whereas it is delivered to Asp367 through the hydrogen-bond network of coordinated water molecules in the Glu234Ala mutant. The present findings were inspirational for understanding the catalytic and inhibitory mechanisms of FICD-mediated AMP transfer, paving the way for further studies on the physiological role of FICD protein.

Preparation of Fe/C-MgCO3 micro-electrolysis fillers and mechanism of phosphorus removal.

Iron-carbon micro-electrolysis is effective for the removal of phosphorus in wastewater; however, meeting the stringent emission standards required for treatment is difficult. To meet these treatment standards, modified micro-electrolytic fillers were prepared from iron dust, powdered activated carbon, clay, and additives using an elevated temperature roasting process under an inert atmosphere. The results show that among several additives, the modified micro-electrolytic (Fe/C-MgCO3) fillers using MgCO3 were the most effective at phosphorus removal. The preparation conditions for the Fe/C-MgCO3 fillers and their effects on phosphorus removal performance were investigated. Under the optimal preparation conditions (calcination temperature: 800 °C, Fe/C = 4:1, clay content 20%, and 5% MgCO3), the filler yielded a high compressive strength of 3.5 MPa, 1 h water absorption rate of 25.7%, and specific surface area and apparent density of 154.2 m2/g and 2689.2 kg/m3, respectively. The iron-carbon micro-electrolysis process removed 97% of phosphorus in the wastewater by using the Fe/C-MgCO3 fillers, which was 14% more than the Fe/C filler. Electrostatic adsorption and surface precipitation were identified as the main phosphorus removal mechanisms, and the surface of the Fe/C-MgCO3 filler was continuously updated. These results demonstrated that Fe/C-MgCO3 is a promising filler for phosphorus removal in water treatment.

Mechanical Stretch Promotes Neurite Outgrowth of Primary Cultured Dorsal Root Ganglion Neurons via Suppression of Semaphorin 3A-Neuropilin-1/Plexin-A1 Signaling.

Significant attempts have been made to promote neuronal extension and migration in nerve development and regeneration. Although mechanical stretch induces persistent elongation of the axon, the underlying molecular mechanisms are not yet clear. Some axonal guidance cues secreted in the growth cone that affect the axonal growth could attract or repel axons in neurite connection. As semaphorin 3A (Sema3A) is an important repulsion guidance molecule, inhibition of Sema3A has been postulated to promote neuronal development. In this study, the effects of mechanical stretch on dorsal root ganglion neuronal growth and the underlying mechanisms were investigated by assessing the extension direction, neurite length, cell body size, mitochondrial membrane potential, and the expression of Sema3A and its receptors. Our results showed that cell viability significantly increased at tensile strains of 2.5, 5, and 10% for 4 h, with the most prominent effect at 5% tensile strain. Moreover, neurons migrated closer to the stretching direction at 5% tensile strain (0-12 h), while the neurons of the control group moved in a disorderly manner. Furthermore, Sema3A-Neuropilin-1/Plexin-A1 signaling pathway was found to be suppressed after mechanical stretch at 5% tensile strain for 4 h by immunofluorescence staining, immunoprecipitation, and western blot assay. Finally, a Sema3A-SiRNA (SiRNA = small interfering RNA) treatment led to remarkable guidance growth in the stretch-grown neurons. Importantly, there was significant decrease of repulsive cue Sema3A expression and remarkable increase of attractive molecule Netrin-1 expression after mechanical stretching treatment, which jointly promoted neurite outgrowth. This study provides a promising new approach for the development of mechanical stretching therapy or guidance factor-related drugs in injured neuronal regeneration.

Serum cystatin C is a potential predictor of short-term mortality and acute kidney injury in acute aortic dissection patients: a retrospective cohort study.

Background: Serum cystatin C concentration is associated with cardiovascular disease. However, the relationship between cystatin C and acute aortic dissection (AAD) remains unclear. In the current study, we aim to evaluate the predictive value of cystatin C in the occurrence of acute kidney injury (AKI) and the prognosis of AAD patients. Methods: The patients with AAD admitted to our hospital from November 2019 through January 2022 were consecutively included in the retrospective cohort study. A complete blood cell count, serum biochemistry tests, including cystatin C and creatinine, in-hospital mortality and the incidence of AKI were recorded. All the patients were categorized into four groups according to the quartile of their serum cystatin C levels. Multivariate logistic and Cox regression analyses were conducted to determine the independent risk factors for the incidence of AKI and the prognosis of AAD patients, respectively. Kaplan-Meier analyses and log-rank tests were used to evaluate differences in survival. Receiver operating characteristic (ROC) curves were used to assess the predictive value of cystatin C for short-term mortality and the incidence of AKI in AAD patients. Results: A total of 357 patients were included in this study. The results showed that the higher the concentration of cystatin C, the higher the level of serum creatinine and the higher the incidence of AKI. Mortality was significantly higher in the group with serum cystatin C levels >1.18 mg/L. Type A AAD, white blood cell count >10×109/L, platelet count <100×109/L, and serum cystatin C concentration >1.18 mg/L [adjusted hazards ratio (HR) =2.405, 95% confidence interval (CI), 1.029-4.063, P=0.041] were independent risk factors for in-hospital mortality. Cystatin C levels >1.18 mg/L remained an independent predictor of AKI in AAD after adjusting for the confounding [odds ratio (OR) 76.489, 95% CI, 25.586-228.660]. The areas under the ROC curves of cystatin C in predicting the mortality and incidence of AKI in AAD patients were 0.655 (95% CI, 0.551-0.760) and 0.807 (95% CI, 0.758-0.856), respectively. Conclusions: In sum, serum cystatin C concentration is a potential predictor of short-term mortality and the incidence of AKI in AAD patients.

Patient satisfaction and its health provider-related determinants in primary health facilities in rural China.

BACKGROUND: Patient satisfaction is an important outcome measure of health service and is one of the main reasons for the gradual deterioration of doctor-patient relationships in China. This study used the standardized patient (SP) method to explore patient satisfaction and its health provider-related determinants among primary health facilities in rural China. METHODS: The dataset comprised 1138 clinic cases in 728 rural primary health facilities in 31 counties, spread across four provinces. Information regarding the consultation interaction between the unannounced SPs and primary physicians was recorded. Patient satisfaction was gathered from the feedback of SPs after the visit. RESULTS: The overall average score of SP satisfaction with rural primary health facilities was only 13.65 (SD = 3.22) out of 20. The SP scores were found to be consistent with those of real patients. After controlling variances in patient population via the SP method, the regression analysis demonstrated that health provider-related factors, such as physician-level characteristics, consultation process, affordability, and convenience, have a significant correlation with patient satisfaction among primary physicians. Among factors relating to physician-level characteristics, affordability, convenience and the consultation process of the visit, the quality of the consultation process (e.g., consultation time, proactively providing necessary instructions and other crucial information) were found to be the prominent determinants. CONCLUSIONS: This study revealed the need to improve patient satisfaction in primary health facilities in rural China. To solve this issue, we recommend that policies to increase medical service quality be implemented in rural primary healthcare systems.

NewtonNet: a Newtonian message passing network for deep learning of interatomic potentials and forces.

We report a new deep learning message passing network that takes inspiration from Newton's equations of motion to learn interatomic potentials and forces. With the advantage of directional information from trainable force vectors, and physics-infused operators that are inspired by Newtonian physics, the entire model remains rotationally equivariant, and many-body interactions are inferred by more interpretable physical features. We test NewtonNet on the prediction of several reactive and non-reactive high quality ab initio data sets including single small molecules, a large set of chemically diverse molecules, and methane and hydrogen combustion reactions, achieving state-of-the-art test performance on energies and forces with far greater data and computational efficiency than other deep learning models.

Removal of Chromium(VI) by Nanoscale Zero-Valent Iron Supported on Melamine Carbon Foam.

The overuse of chromium (Cr) has significantly negatively impacted human life and environmental sustainability. Recently, the employment of nano zero-valent iron (nZVI) for Cr(VI) removal is becoming an emerging approach. In this study, carbonized melamine foam-supported nZVI composites, prepared by a simple impregnation-carbonization-reduction method, were assessed for efficient Cr(VI) removal. The prepared composites were characterized by XPS, SEM, TEM, BET and XRD. Batch experiments at different conditions revealed that the amount of iron added, the temperature of carbonization and the initial Cr(VI) concentration were critical factors. Fe@MF-12.5-800 exhibited the highest removal efficiency of 99% Cr(VI) (10 mg/L) at neutral pH among the carbonized melamine foam-supported nZVI composites. Its iron particles were effectively soldered onto the carbonaceous surfaces within the pore networks. Moreover, Fe@MF-12.5-800 demonstrated remarkable stability (60%, 7 days) in an open environment compared with nZVI particles.

A benchmark dataset for Hydrogen Combustion.

The generation of reference data for deep learning models is challenging for reactive systems, and more so for combustion reactions due to the extreme conditions that create radical species and alternative spin states during the combustion process. Here, we extend intrinsic reaction coordinate (IRC) calculations with ab initio MD simulations and normal mode displacement calculations to more extensively cover the potential energy surface for 19 reaction channels for hydrogen combustion. A total of ∼290,000 potential energies and ∼1,270,000 nuclear force vectors are evaluated with a high quality range-separated hybrid density functional, ωB97X-V, to construct the reference data set, including transition state ensembles, for the deep learning models to study hydrogen combustion reaction.

Enhanced Fenton removal of phenol catalyzed by a modified red mud derived from the reduction of oxalic acid and L-ascorbic acid.

Red mud, a bauxite residue generated during alumina production through the Bayer process, contains oxides of Fe, Ti, Al, Mn, and rare earths, and has a latent performance for catalytic removal of phenol. We proposed a novel and facile approach for red mud modification by the reduction of oxalic acid and L-ascorbic acid in the acidic solution. By surveying characteristics of modified red mud and influencing factors of phenol removal, the optimum experiment conditions and the possible mechanism were explored, respectively. The results demonstrated that RO2V2 (treated red mud using 2 g of oxalic acid dehydrate and 2 g of L-ascorbic acid) and RO3V3 (treated red mud using 3 g of oxalic acid dehydrate and 3 g of L-ascorbic acid) showed the most efficient catalytic capacity for the phenol removal and removal efficiency of over 99.1% for the 200 mg/L of phenol solution within 5 min among investigated catalysts with the pH decreasing from 6.7 to 3. The excellent catalytic performance of modified red mud profited from the production of Fe3O4, Fe2O3, Mn2O3, Fe2SiO4, and FeTiO3 in the catalysts. It was motivating for removal of phenol to increase the dosage of catalyst and H2O2. The rate constants of the pseudo-first-order kinetics model of RO2V2 and RO3V3 were 1.0 and 1.073, respectively. The results of continuous experiments provided a positive reference for a future pilot scale test.

Highly dispersed and stable nano zero-valent iron doped electrospun carbon nanofiber composite for aqueous hexavalent chromium removal.

In this work, a nZVI doped electrospun carbon nanofiber (nZVI-CNF) composite was prepared and applied for aqueous hexavalent chromium (Cr(vi)) removal. Firstly, FeCl3/PAN nanofibers were prepared by a simple electrospinning method; Then, nZVI-CNFs were obtained by carbonization of FeCl3/PAN nanofibers at 800 °C. The surface morphology and internal structure of nZVI-CNFs were characterized by SEM and TEM, showing that the uniformly dispersed nZVI particles were well integrated into the carbon layer structure. The Cr(vi) removal efficiency of nZVI-CNFs was 91.5% with a Cr(vi) concentration of 10 mg L-1 and the mechanism was further studied by XRD and XPS. Meanwhile, the nZVI-CNFs exhibited good stability over a wide range of pH values from 4-8 and a long time placement stability. Furthermore, nZVI-CNFs can be used as a filter membrane for continuous treatment of wastewater, suggesting great potential for practical application.

Study on the Influence of Shear Stress and Pulse Electrical Stimulation to the Growth of Cardiomyocytes.

Engineered myocardial tissue is expected to be used in the treatment of myocardial defects and other diseases, and one of the keys is to construct a suitable environment for the culture of myocardial tissue in vitro. In this study, flow shear stress and pulse electrical stimulation were applied to cardiomyocytes with a self-designed device by simulating the mechanical and electrical physiological microenvironment of myocardial tissue. The strength and duration of pulse electrical stimulation as well as the intensity of shear stress were studied in detail to optimize the experimental parameters. Concretely, 100 mV pulse electrical stimulation (1 Hz and 10 ms pulse width) and 10 dyn/cm² shear stress were used for studying the influence of combined mechanical-electrical stimulation to the growth of cardiomyocytes. The mechanical factor of the combined stimulation promoted the expression of α-cardiac actin mRNA, the electrical factor caused an increase in Cx-43 mRNA expression, and shear stress and pulse electrical stimulation showed a synergistic action on the expression of GATA-4 mRNA. It indicated that combined mechanical-electrical stimulation had a better effect on the functionalized culture of cardiomyocytes, which provided an important theoretical basis for the further construction of in vitro engineered myocardial tissue.

Correlation Between Retinopathy and Coronary Microcirculation Dysfunction in Patients with Type 2 Diabetes Mellitus.

PURPOSE: The aim of this study is to evaluate the correlation between retinopathy and coronary microcirculation dysfunction (CMD) in type 2 diabetes mellitus (T2DM) patients. METHODS: 198 T2DM patients with left ventricular ejection fraction (LVEF)>50%, no epicardial coronary artery stenosis diagnosis by coronary angiography (CAG) and successfully completed coronary blood flow reserve (CFR) test and laboratory examination were enrolled, and fundus examination was performed on all participants. Two groups were divided according to CFR value, including 86 patients with CMD (CFR≤2.5) in study group and 112 patients without CMD (CFR>2.5) in control group. The composition of various retinopathy in two groups was observed, and the correlation between retinopathy and CMD was analyzed using ordered logistic regression. RESULTS: There were 13 cases with arteriovenous (A/V) nicking, 4 cases with proliferative diabetic retinopathy (PDR), 14 cases with non-proliferative diabetic retinopathy (NPDR), 17 cases with diabetic retinopathy (DR) with A/V nicking, 38 cases without retinopathy in study group, and 18 cases, 7 cases, 20 cases, 4 cases and 63 cases for each in control group. After adjustment for age, gender, hypertension, diabetes duration, dyslipidemia, glycosylated hemoglobin (HbA1c), body mass index (BMI), A/V nicking, PDR and NPDR, the diference of DR with A/V nicking between study and control group remained statistically signifcant (OR 2.0, 95% CI 0.79 to 3.21, p = 0.001). CONCLUSION: DR with A/V nicking could be used as an independent predictor of T2DM patients with CMD. CFR testing should be performed on patients with this kind of eye sign, even if they do not have any symptoms of heart disease. Meanwhile, DR with A/V nicking might be served as a reference indicator of CMD in T2DM patients with chest pain who were unable to be tested for CFR.

Development of a Many-Body Force Field for Aqueous Alkali Metal and Halogen Ions: An Energy Decomposition Analysis Guided Approach.

Aqueous solutions of alkyl/alkaline metal and halide ions play a crucial functional role in biological systems such as proteins, membranes, and nucleic acids and for interfacial chemistry in geomedia and in the atmosphere. We present the MB-UCB many-body force field for monovalent and divalent ions that includes polarization, charge penetration to describe the short-range permanent electrostatics accurately, as well as a model for charge transfer to better describe the quantum mechanical potential energy surface and its components obtained from the absolutely localized molecular orbital energy decomposition analysis (ALMO-EDA). We find that the MB-UCB force field is in very good agreement with a validation suite of ion-ion and ion-water cluster data, exhibiting overall better cancellation of errors among energy components, unlike the case for other many-body potentials that do not utilize an EDA scheme. However, limitations in the functional form for the classical many-body energy components do limit the best achievable accuracy through complete cancellation of error and warrant further study.

Hexavalent Chromium as a Smart Switch for Peroxidase-like Activity Regulation via the Surface Electronic Redistribution of Silver Nanoparticles Anchored on Carbon Spheres.

Although some ions, due to their unique chemical properties, can regulate the enzyme-like activity of nanomaterials, it is still a huge challenge to explore the mechanism of regulation. Herein, we found that Cr6+ (CrO42-) as a smart switch can significantly increase the peroxidase-like (POD-like) activity of silver nanoparticles (Ag NPs), which were anchored efficiently on carbon spheres (Cal-CS/PEG/Ag) using amino-modified poly(ethylene glycol) (PEG) as a bridge. Density functional theory (DFT) calculations demonstrated that the addition of Cr6+ can not only adjust the surface electronic redistribution of Ag atoms but also improve the geometric structure of the adsorbed intermediate, which resulted in the optimization of free energy and change of bond lengths in the catalytic reaction process, increasing the POD-like activity of Cal-CS/PEG/Ag. Based on the Cr6+-increased POD-like activity of Cal-CS/PEG/Ag, we successfully constructed a visual sensor of Cr6+ along with quantitative analysis by the UV spectrum. The sensor has good selectivity for other 29 interfering ions and molecules with a detection limit of 79 nM. In this work, the detailed mechanism of the Cr6+-increased POD-like activity of Ag NPs was studied and a new possibility for the rational design of ion visual sensors using nanomaterials was proposed.