Exploring the weak visible-near-infrared and NO2detection capabilities of PbS/Sb2O5heterostructures with DFT interpretations.

The need for photosensors and gas sensors arises from their pivotal roles in various technological applications, ensuring enhanced efficiency, safety, and functionality in diverse fields. In this paper, interlinked PbS/Sb2O5thin film has been synthesized by a magnetron sputtering method. We control the temperature to form the nanocomposite by using their different nucleation temperature during the sulfonation process. A nanostructured PbS/Sb2O5with cross-linked morphology was synthesized by using this fast and efficient method. This method has also been used to grow a uniform thin film of nanocomposite. The photo-sensing and gas-sensing properties related to the PbS/Sb2O5compared with those of other nanomaterials have also been investigated. The experimental and theoretical calculations reveal that the PbS/Sb2O5exhibits extraordinarily superior photo-sensing and gas-sensing properties in terms of providing a pathway for electron transport to the electrode. The attractive highly sensitive photo and gas sensing properties of PbS/Sb2O5make them applicable for many different kinds of applications. The responsivity and detectivity of PbS/Sb2O5are 0.28 S/mWcm-2and 1.68 × 1011Jones respectively. The sensor response towards NO2gas was found to be 0.98 at 10 ppb with an limit of detection (LOD) of 0.083 ppb. The PbS/Sb2O5exhibits high selectivity towards the NO2gas. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) were used to analyze the geometries, electronic structure, and electronic absorption spectra of a light sensor fabricated by PbS/Sb2O5. The results are very analogous to the experimental results. Both photosensors and gas sensors are indispensable tools that contribute significantly to the evolution of technology and the improvement of various aspects of modern life.

Factors influencing willingness to participate in ophthalmic clinical trials and strategies for effective recruitment.

AIM: To explore the factors influencing individuals' willingness to participate in ophthalmic clinical trials. METHODS: A questionnaire survey was conducted from January to April 2021 among patients and their family members at Zhongshan Ophthalmic Center, Sun Yat-sen University, in Guangzhou, China. The survey gathered data on respondents' willingness, demographic and socioeconomic profiles, as well as their reasons and concerns regarding engagement in clinical trials. RESULTS: Of the 1078 residents surveyed (mean age 31.2±13.1y; 65.8% females) in Guangzhou, 749 (69.5%) expressed a willingness to participate in future ophthalmic clinical trials. Specific characteristics associated with greater willingness included a younger age, lower annual income, higher education, prior participation experience, previous ophthalmic treatment, and a better understanding of clinical trials. With the exception of age, these characteristics were significantly linked to a higher willingness. The primary barrier to participation, expressed by 64.8% of those willing and 54.4% of those unwilling, was "Uncertain efficacy". In terms of motivations, the willing group ranked "Better therapeutic benefits" (35.0%), "Professional monitoring" (34.3%), and "Trust in healthcare professionals" (33.1%) as their top three reasons, whereas the unwilling participants indicated "Full comprehension of the protocol" (46.2%) as the key facilitator. CONCLUSION: This study reveals a substantial willingness to participate in ophthalmic clinical trials and demonstrates the predictive role of demographic and socioeconomic factors. Variations in motivators and concerns between willing and unwilling participants highlight the significance of tailored recruitment strategies. Importantly, the need for and trust in healthcare professionals stand out as powerful motivations, underscoring the importance of enhancing physician-patient relationships, adopting patient-centered communication approaches, and addressing individualized needs to improve accrual rates.

A simple and fast method for the fabrication of p-typeß-Ga2O3by electrochemical oxidation method with DFT interpretation.

In this work, a simple electrochemical oxidation method has been used to prepare p-typeß-Ga2O3nanoparticles. This method overcomes the problem of doping high energy gap semiconductors to form p-type. The electron holes ofß-Ga2O3were caused by oxygen vacancy (Vo) and showed the shorter lattice constant and preferred orientation in XRD analysis. The peak area of oxygen vacancy also reflects a higher ratio than n-type Ga2O3in x-ray photoelectron spectroscopy (XPS). The adsorption of reducing gas (CO, CH4, and H2) enhanced the resistance of theß-Ga2O3confirming the p-type character of NPs. The DFT calculations showed that oxygen vacancy leads to higher energy of the Fermi level and is near the valence band. The binding energy of Ga2O3and after interaction with gas molecular was also calculated which is analogous to our experimental data.

U(1) dynamics in neuronal activities.

Neurons convert external stimuli into action potentials, or spikes, and encode the contained information into the biological nervous system. Despite the complexity of neurons and the synaptic interactions in between, rate models are often adapted to describe neural encoding with modest success. However, it is not clear whether the firing rate, the reciprocal of the time interval between spikes, is sufficient to capture the essential features for the neuronal dynamics. Going beyond the usual relaxation dynamics in Ginzburg-Landau theory for statistical systems, we propose that neural activities can be captured by the U(1) dynamics, integrating the action potential and the "phase" of the neuron together. The gain function of the Hodgkin-Huxley neuron and the corresponding dynamical phase transitions can be described within the U(1) neuron framework. In addition, the phase dependence of the synaptic interactions is illustrated and the mapping to the Kinouchi-Copelli neuron is established. It suggests that the U(1) neuron is the minimal model for single-neuron activities and serves as the building block of the neuronal network for information processing.

Revealing a Highly Sensitive Sub-ppb-Level NO2 Gas-Sensing Capability of Novel Architecture 2D/0D MoS2/SnS Heterostructures with DFT Interpretation.

In this work, we use a chemical method to design novel 2D-material/0D-quantum dot (MoS2/SnS) heterostructures. Furthermore, the unique 2D/0D heterostructure enhanced the NO2 gas-sensing capability 3 times and increased the sensing recoverability by more than 90%. Advanced characterization tools such as SEM, TEM, XRD, and AFM confirm the formation of MoS2/SnS heterojunction nanomaterials. Using AFM data, the average thickness of the MoS2 layer was found to be 5 nm. The highest sensor response of 0.33 with good repeatability was observed at 250 ppb of NO2. Sensing characterization reveals the ultra-fast response time, that is, 74 s, at 50 ppb of NO2. The limit of detection for detecting NO2 was also found to be very low, that is, 0.54 ppb, by using MoS2/SnS heterostructures. The theoretical calculations based on density functional theory well corroborated and quantified the intermolecular interaction and gas adsorption on the surface of MoS2/SnS.

Anti-inflammatory and neuroprotective effects of natural cordycepin in rotenone-induced PD models through inhibiting Drp1-mediated mitochondrial fission.

Accumulating evidences suggest that inflammation-mediated neurons dysfunction participates in the initial and development of Parkinson's disease (PD), whereas mitochondria have been recently recognized as crucial regulators in NLRP3 inflammasome activation. Cordycepin, a major component of cordyceps militaris, has been shown to possess neuroprotective and anti-inflammatory activity. However, the effects of cordycepin in rotenone-induced PD models and the possible mechanisms are still not fully understood. Here, we observed that motor dysfunction and dopaminergic neurons loss induced by rotenone exposure were ameliorated by cordycepin. Cordycepin also reversed Drp1-mediated aberrant mitochondrial fragmentation through increasing AMPK phosphorylation and maintained normal mitochondrial morphology. Additionally, cordycepin effectively increased adenosine 5'-triphosphate (ATP) content, mitochondrial membrane potential (MMP), and reduced mitochondrial ROS levels, as well as inhibited complex 1 activity. More importantly, cordycepin administration inhibited the expression of NLRP3 inflammasome components and the release of pro-inflammatory cytokine in rotenone-induced rats and cultured neuronal PC12 cells. Moreover, we demonstrated that the activation of NLRP3 inflammasome within neurons could be suppressed by the mitochondrial division inhibitor (Mdivi-1). Collectively, the present study provides evidence that cordycepin exerts neuroprotective effects partially through preventing neural NLRP3 inflammasome activation induced by Drp1-dependent mitochondrial fragmentation in rotenone-injected PD models.

Pairing mechanism in multiband superconductors.

It has been a long-standing puzzle why electrons with repulsive interactions can form pairs in unconventional superconductors. Here we develop an analytic solution for renormalization group analysis in multiband superconductors, which agrees with the numerical results exceedingly well. The analytic solution allows us to construct soluble effective theory and answers the pairing puzzle: electrons form pairs resonating between different bands to compensate the energy penalty for bring them together, just like the resonating chemical bonds in benzene. The analytic solutions allow us to explain the peculiar features of critical temperatures, spin uctuations in unconventional superconductors and can be generalized to cuprates where the notion of multibands is replaced by multipatches in momentum space.

Anomalous isotope effect in iron-based superconductors.

The role of electron-phonon interactions in iron-based superconductor is currently under debate with conflicting experimental reports on the isotope effect. To address this important issue, we employ the renormalization-group method to investigate the competition between electron-electron and electron-phonon interactions in these materials. The renormalization-group analysis shows that the ground state is a phonon-dressed unconventional superconductor: the dominant electronic interactions account for pairing mechanism while electron-phonon interactions are subdominant. Because of the phonon dressing, the isotope effect of the critical temperature can be normal or reversed, depending on whether the retarded intra- or inter-band interactions are altered upon isotope substitutions. The connection between the anomalous isotope effect and the unconventional pairing symmetry is discussed at the end.

Different CO2 acclimation strategies in juvenile and mature leaves of Ottelia alismoides.

The freshwater macrophyte, Ottelia alismoides, is a bicarbonate user performing C4 photosynthesis in the light, and crassulacean acid metabolism (CAM) when acclimated to low CO2. The regulation of the three mechanisms by CO2 concentration was studied in juvenile and mature leaves. For mature leaves, the ratios of phosphoenolpyruvate carboxylase (PEPC) to ribulose-bisphosphate carboxylase/oxygenase (Rubisco) are in the range of that of C4 plants regardless of CO2 concentration (1.5-2.5 at low CO2, 1.8-3.4 at high CO2). In contrast, results for juvenile leaves suggest that C4 is facultative and only present under low CO2. pH-drift experiments showed that both juvenile and mature leaves can use bicarbonate irrespective of CO2 concentration, but mature leaves have a significantly greater carbon-extracting ability than juvenile leaves at low CO2. At high CO2, neither juvenile nor mature leaves perform CAM as indicated by lack of diurnal acid fluctuation. However, CAM was present at low CO2, though the fluctuation of titratable acidity in juvenile leaves (15-17 µequiv g-1 FW) was slightly but significantly lower than in mature leaves (19-25 µequiv g-1 FW), implying that the capacity to perform CAM increases as leaves mature. The increased CAM activity is associated with elevated PEPC activity and large diel changes in starch content. These results show that in O. alismoides, carbon-dioxide concentrating mechanisms are more effective in mature compared to juvenile leaves, and C4 is facultative in juvenile leaves but constitutive in mature leaves.

Collective resonances near zero energy induced by a point defect in bilayer graphene.

Intrinsic defects give rise to scattering processes governing the transport properties of mesoscopic systems. We investigate analytically and numerically the local density of states in Bernal stacking bilayer graphene with a point defect. With Bernal stacking structure, there are two types of lattice sites. One corresponds to connected sites, where carbon atoms from each layer stack on top of each other, and the other corresponds to disconnected sites. From our theoretical study, a picture emerges in which the pronounced zero-energy peak in the local density of states does not attribute to zero-energy impurity states associated to two different types of defects but to a collective phenomenon of the low-energy resonant states induced by the defect. To corroborate this description, we numerically show that at small system size N, where N is the number of unit cells, the zero-energy peak near the defect scales as 1/lnN for the quasi-localized zero-energy state and as 1/N for the delocalized zero-energy state. As the system size approaches to the thermodynamic limit, the former zero-energy peak becomes a power-law singularity 1/|E| in low energies, while the latter is broadened into a Lorentzian shape. A striking point is that both types of zero-energy peaks decay as 1/r2 away from the defect, manifesting the quasi-localized character. Based on our results, we propose a general formula for the local density of states in low-energy and in real space. Our study sheds light on this fundamental problem of defects.

Responses of Ottelia alismoides, an aquatic plant with three CCMs, to variable CO2 and light.

Ottelia alismoides is a constitutive C4 plant and bicarbonate user, and has facultative crassulacean acid metabolism (CAM) at low CO2. Acclimation to a factorial combination of light and CO2 showed that the ratio of phosphoenolpyruvate carboxylase (PEPC) to ribulose-bisphosphate carboxylase/oxygenase (Rubisco) (>5) is in the range of that of C4 plants. This and short-term response experiments showed that the activity of PEPC and pyruvate phosphate dikinase (PPDK) was high even at the end of the night, consistent with night-time acid accumulation and daytime carbon fixation. The diel acidity change was maximal at high light and low CO2 at 17-25 µequiv g-1 FW. Decarboxylation proceeded at ~2-3 µequiv g-1 FW h-1, starting at the beginning of the photoperiod, but did not occur at high CO2; the rate was greater at high, compared with low light. There was an inverse relationship between starch formation and acidity loss. Acidity changes account for up to 21% of starch production and stimulate early morning photosynthesis, but night-time accumulation of acid traps <6% of respiratory carbon release. Ottelia alismoides is the only known species to operate CAM and C4 in the same tissue, and one of only two known aquatic species to operate CAM and bicarbonate use.

Edge magnetism of Heisenberg model on honeycomb lattice.

Edge magnetism in graphene sparks intense theoretical and experimental interests. In the previous study, we demonstrated the existence of collective excitations at the zigzag edge of the honeycomb lattice with long-ranged Néel order. By employing the Schwinger-boson approach, we show that the edge magnons remain robust even when the long-ranged order is destroyed by spin fluctuations. Furthermore, in the effective field-theory limit, the dynamics of the edge magnon is captured by the one-dimensional relativistic Klein-Gordon equation. It is intriguing that the boundary field theory for the edge magnon is tied up with its bulk counterpart. By performing density-matrix renormalization group calculations, we show that the robustness may be attributed to the closeness between the ground state and the Néel state. The existence of edge magnon is not limited to the honeycomb structure, as demonstrated in the rotated-square lattice with zigzag edges as well. The universal behavior indicates that the edge magnons may attribute to the uncompensated edges and can be detected in many two-dimensional materials.

[Relationship between pCO2 and algal biomass in Xiangxi Bay in spring].

Water temperature (WT), pH, HCO3-, dissolved oxygen and the concentration of Chl-a in Xiangxi Bay were measured in spring. The partial pressure of carbon dioxide was calculated by the chemical balance and Henry's Law while CO2 flux by the thin-layer diffusion model. Results showed that pCO2 of surface water in Xiangxi Bay varied from 8.34 microatm to 168.70 microatm with a mean of 49.01 microatm. pCO2 increased along the stream with Chl-a decreased from upstream to the estuary. The mean of pCO2 was 117.92 microatm on the diurnal scale, ranging from 74.43 microatm to 168.70 microatm, and the mean concentration of Chl-a was 3.04 mg x m(-3) with the range from 2.22 mg x m(-3) to 4.55 mg x m(-3). There were statistically significant negative correlations between values for pCO2 and Chl-a (r = -0.844, P < 0.01). Phytoplankton photosynthesis in Xiangxi Bay played a crucial role in the spatial and temporal distribution of pCO2. The undersaturation observed suggests that surface waters in Xiangxi Bay represented a sink for atmospheric CO2 in spring, and the exchange rate of CO2 was estimated to be -35.17 mmol x (m2 x d)(-1).

[Diurnal changes in greenhouse gases at water-air interface of Xiangxi River in autumn and their influencing factors].

With the closed chamber and gas chromatography method, a 24-hour continuous monitoring was carried out to understand the greenhouse gases fluxes across the water-air interface of the Xiangxi River Bay, the Three-Gorges Reservoir in Autumn. Results indicated that the fluxes of CO2, CH4 and N2O across the water-air interface showed an obvious diurnal variation. The absorption and emission process of CH4 showed strong diurnal variation during the experimental period, reaching the highest emission at 1 am, whereas CO2 and N2O were emitted all day. The fluxes of CO2 ranged from 20.1-97.5 mg x (m2 x h)(-1) at day and 32.7-42.5 mg x (m2 x h)(-1) at night, the fluxes of N2O ranged from 18.4-133.7 microg x (m2 x h)(-1) at day and 42.1-102.6 microg x (m2 x h)(-1) at night. The fluxes of CO2 had positive correlation with wind speed and negative correlation with pH. The fluxes of N2O had positive correlation with pH.

[Preliminary study on normal values of blue-on-yellow perimetry in central thirty degrees].

OBJECTIVE: To investigate the normal values and related factors of blue on yellow perimetry (BYP) in the central 30 degree. METHODS: A cross sectional study design was performed on this study. BYP was performed in a Humphery750II-i perimetry with 30-2 procedure and Fastpac strategy. The study samples consisted of 116 eyes of 58 normal subjects. The visual field indices were calculated and their related factors were analyzed. SPSS 13.0 software package was used for experiment data analysis. Comparison of three blue-on-yellow visual indices, including mean sensitivity (MS), mean defect (MD) and pattern standard deviation (PSD), were investigated by multi-way ANOVA with randomized block design method among four age groups. Relationship between age and visual field index was described and interpreted by calculating Pearson product-moment correlation coefficient and linear regression. Chi-square test was applied to determine the distribution of population and gender among four age groups. Significance level was set to alpha = 0.05. RESULTS: Values of the three different visual indices, MS, MD and pattern PSD, in central 30 degree of BYP were (21.23 +/- 2.96) dB, (-3.94 +/- 2.20) dB and (3.13 +/- 0.72) dB, respectively. The differences of MS, MD and PSD values between right eye and left eye were not statistically significant (F = 0.488, 0.833, and 0.677, with P = 0.487, 0.482 and 0.414, respectively). No differences in these three indices could be detected between male and female (F = 0.149, 0.547 and 1.948, with P = 0.702, 0.463 and 0.169, respectively). Significant difference in three visual field indices was identified among four different age groups (F = 48.160, 54.250 and 9.329, with P = 0.000, 0.000 and 0.032, respectively). The light average sensitivity in four quadrants showed statistically significant difference in all age groups (F value for quadrant factor was 81.544, P = 0.000). The MS value decreased 2.5 dB and the MD value increased -0.932 dB with the 10-year-old increasing. The average sensitivity in different eccentric ranges had a significant statistical difference (F value for eccentricity factor was 48.257, P = 0.000). CONCLUSIONS: The gender and the laterality do not affect the MS, MD and PSD in the BYP of normal subjects. The light average sensitivity is asymmetry in the four different quadrant, decreases in a linear decline with age and declines with the eccentricity.

The role of glutathione metabolism in tolerance of tobacco BY-2 suspension cells to microcystin-RR.

This study was undertaken to investigate the role of the glutathione-involved detoxifying mechanism in defending the tobacco BY-2 suspension cells against microcystin-RR (MC-RR). Analysis showed that exposure of the cells to different concentrations of MC-RR (0.1, 1 and 10 microg/mL) for 0-6 days resulted in a time and concentration-dependent decrease in cell viability and increase in reactive oxygen species (ROS) content. Reduced glutathione (GSH) and total glutathione (tGSH) content as well as glutathione reductase (GR), glutathione peroxidase (GPX) and glutathione-S-transferase (GST) activities significantly increased after 3-4 days exposure in the highest two concentration treated groups, while decreased until reaching the control values except for GPX at day 6. Oxidized glutathione (GSSG) content markedly increased compared with control in high concentration MC-RR treated group after 6 days exposure. The GSH/GSSG ratio was much higher than control in 10 microg/mL MC-RR treated group at day 4, but after 6 days exposure, the ratios in all treated groups were lower than that of the control group.

Effects of iron on growth, pigment content, photosystem II efficiency, and siderophores production of Microcystis aeruginosa and Microcystis wesenbergii.

Changes in growth, photosynthetic pigments, and photosystem II (PS II) photochemical efficiency as well as production of siderophores of Microcystis aeruginosa and Microcystis wesenbergii were determined in this experiment. Results showed growths of M. aeruginosa and M. wesenbergii, measured by means of optical density at 665 nm, were severely inhibited under an iron-limited condition, whereas they thrived under an iron-replete condition. The contents of chlorophyll-a, carotenoid, phycocyanin, and allophycocyanin under an iron-limited condition were lower than those under an iron-replete condition, and they all reached maximal contents on day 4 under the iron-limited condition. PS II photochemical efficiencies (maximal PS II quantum yield), saturating light levels (I(k)) and maximal electron transport rates (ETR(max)) of M. aeruginosa and M. wesenbergii declined sharply under the iron-limited condition. The PS II photochemical efficiency and ETR(max) of M. aeruginosa rose , whereas in the strain of M. wesenbergii, they declined gradually under the iron-replete condition. In addition, I ( k ) of M. aeruginosa and M. wesenbergii under the iron-replete condition did not change obviously. Siderophore production of M. aeruginosa was higher than that of M. wesenbergii under the iron-limited condition. It was concluded that M. aeruginosa requires higher iron concentration for physiological and biochemical processes compared with M. wesenbergii, but its tolerance against too high a concentration of iron is weaker than M. wesenbergii.