Polarization Functions Research Articles

Phosphorylation-dependent activation of the bHLH transcription factor ICE1/SCRM promotes polarization of the Arabidopsis zygote.

In Arabidopsis thaliana, the asymmetric cell division (ACD) of the zygote gives rise to the embryo proper and an extraembryonic suspensor, respectively. This process is controlled by the ERECTA-YODA-MPK3/6 receptor kinase-MAP kinase-signaling pathway, which also orchestrates ACDs in the epidermis. In this context, the bHLH transcription factor ICE1/SCRM is negatively controlled by MPK3/6-directed phosphorylation. However, it is unknown whether this regulatory module is similarly involved in the zygotic ACD. We investigated the function of SCRM in zygote polarization by analyzing the effect of loss-of-function alleles and variants that cannot be phosphorylated by MPK3/6, protein accumulation, and target gene expression. Our results show that SCRM has a critical function in zygote polarization and acts in parallel with the known MPK3/6 target WRKY2 in activating WOX8. Our work further demonstrates that SCRM activity in the early embryo is positively controlled by MPK3/6-mediated phosphorylation. Therefore, the effect of MAP kinase-directed phosphorylation of the same target protein fundamentally differs between the embryo and the epidermis, shedding light on cell type-specific, differential gene regulation by common signaling pathways.

Theoretical studies on the scattering of e± off the C2H2 molecule

Abstract By employing previous models [15,18], we report the differential, integrated elastic, inelastic, total (elastic+inelastic), viscosity and momentum transfer cross sections of e±- C2H2 collision dynamics, for the energy range of 1 eV-1 MeV. This report also incorporates Sherman spin polarization function and total ionization cross section. This work provides the first comprehensive study of electron/positron scattering from C2H2 over such a wide energy range. A complex optical model potential (OMP) has been used to represent the projectile-atom interaction. Relativistic Dirac equation has been solved, to get phase-shifts, needed for the calculations of scattering observables, using OMP. Our results are compared with the existing experimental data and theoretical calculations.

Acoustic Wake in a Singular Isothermal Profile: Dynamical Friction and Gravitational-wave Emission

We consider the motion of a circularly moving perturber in a self-gravitating, collisional system with a spherically symmetric density profile. We concentrate on the singular isothermal sphere, which, despite its pathological features, admits a simple polarization function in linear response theory. This allows us to solve for the acoustic wake trailing the perturber and the resulting dynamical friction, in the limit where the self-gravity of the response can be ignored. In a steady state and for subsonic velocities v p < c s , the dynamical friction torque Fφ∝vp3 is suppressed for perturbers orbiting in an isothermal sphere relative to the infinite, homogeneous medium expectation F φ ∝ v p . For highly supersonic motions, both expectations agree and are consistent with a local approximation to the gravitational torque. At fixed resolution (a given Coulomb logarithm), the response of the system is maximal for Mach numbers near the constant circular velocity of the singular isothermal profile. This resonance maximizes the gravitational-wave (GW) emission produced by the trailing acoustic wake. For an inspiral around a massive black hole of mass 106 M ⊙ located at the center of a (truncated) isothermal sphere, this GW signal could be comparable to the vacuum GW emission of a black hole binary at subnanohertz frequencies when the small black hole enters the Bondi sphere of the massive one. The exact magnitude of this effect depends on departures from hydrostatic equilibrium and on the viscosity present in any realistic astrophysical fluid, which are not included in our simplified description.

Study of halogen interactions in dichlorovinyldiazenes: Structural analysis, DFT simulation and molecular modeling

In recent years, our research group has synthesized about two hundred different dihalogenated vinyldiazenes. The analysis revealed that the type (conformation) of the compounds is the same-"bike stop", but the properties and nature of intermolecular interactions are different. The concepts of the nature of halogen-halogen relationships recommended by IUPAC (2013) do not explain the nature of the observed intermolecular interactions in the synthesized systems. In this paper, for the first time, using the examples of the compounds presented below, an algorithm is built for the relationship between the structure of synthesized compounds and their properties, and the nature of non-covalent interactions involving the chlorine atom.The molecules presented in this paper were studied by the DFT method using the hybrid potential of B3LYP with the Gaussian 09 software package. The extended basis 6-311++G(d,p) with polarization and diffusion functions was used for calculations. Conducted NBO analysis of atomic charge populations. Calculations of the structural parameters of the synthesized systems were carried out in order to study the reactivity, molecular properties and identify the nature of non-covalent interactions involving the halogen atom. It has been established that the Cl–C–Cl triad has a flat geometry and is capable of forming atypical non-covalent interactions both with each other and with various coplanar systems.

Cluster Assembly Dynamics Drive Fidelity of Planar Cell Polarity Polarization.

The planar cell polarity (PCP) signaling pathway polarizes epithelial cells in the tissue plane by segregating distinct molecular subcomplexes to opposite sides of each cell, where they interact across intercellular junctions to form asymmetric clusters. The role of clustering in this process is unknown. We hypothesized that protein cluster size distributions could be used to infer the underlying molecular dynamics and function of cluster assembly and polarization. We developed a method to count the number of monomers of core PCP proteins within individual clusters in live animals, and made measurements over time and space in wild type and in strategically chosen mutants. The data demonstrate that clustering is required for polarization, and together with mathematical modeling provide evidence that cluster assembly dynamics dictate that larger clusters are more likely to be strongly asymmetric and correctly oriented. We propose that cluster assembly dynamics thereby drive fidelity of cell- and tissue-level polarization.

Syn vs. Anti? What Controls Addition Stereochemistry in Chlorolactonization.

The stereochemistry of the uncatalyzed chlorolactonization of 4-phenylpent-4-enoic acid at room temperature was examined to probe the reaction's intrinsic diastereoselectivities as a function of chlorenium ion donor, solvent polarity, and reactant concentration ranges. Kinetic studies using Variable Time Normalization Analysis (VTNA) revealed differing reaction orders for the syn and anti alkene addition processes. Aided and illustrated by quantum chemical modeling, this detailed mechanistic analysis of the substrate's intrinsic chlorolactonization reactions points to concerted AdE3-type paths for both syn and anti additions. By illuminating the factors selecting for syn- vs anti-addition paths, the results provide key reference points for future studies of stereocontrol in halofunctionalization reactions.

Theoretical Investigation of Electric Polarizability in Porphyrin-Zinc and Porphyrin-Zinc-Thiazole Complexes Using Small Property-Oriented Basis Sets.

Porphyrin complexes are of great importance due to their possible applications as sensors, solar cells and photocatalysts, as well as their ability to bind additional ligands. A valuable source of knowledge on their nature is their electric properties, which can be evaluated employing density functional theory (DFT) methods, supporting the experimental research. The present work aims at the application of small property-oriented basis sets in calculation of electric properties in transition metals, their oxides and test coordination complexes. Firstly, the existing polarized ZPol basis set for the first-row transition metals is modified in order to improve atomic polarizability results. For this purpose, optimization of the f-type polarization function exponent is carried out with respect to the value of average atomic polarizability of investigated metals. Next, both the original and the modified basis sets are employed in finite field CCSD(T) calculation of transition metal oxides' dipole moments, as well as DFT calculation of polarizabilities in porphyrin-zinc and porphyrin-zinc-thiazole complexes. The obtained results show that the ZPol and ZPol-A basis sets can be successfully employed in the calculation of linear electric properties in large systems. The optimization procedure used in the present work can be employed for other source basis sets and elements, leading to new efficient polarized basis sets.

The Impact of Bilateral Cerebellar Transcranial Direct Current Stimulation on Balance Control in Healthy Young Adults.

Cerebellar transcranial direct current stimulation (tDCS) has been shown to influence movement functions, but little is known about the specific effects of stimulation polarity on balance control. This study investigated the impact of bilateral cerebellar tDCS on balance functions as a function of stimulation polarity. In this randomized, controlled trial, thirty-nine healthy young adults were assigned to one of three groups: right anodal/left cathodal cerebellar stimulation (AC group), right cathodal/left anodal cerebellar stimulation (CA group), and a control sham group. Each participant underwent a daily 30-minute session of tDCS at 2mA for one week. Balance function was assessed pre- and post-intervention and the data were analyzed using generalized estimating equations. The CA group exhibited a significant reduction in sway area when standing on the left leg and on both stable and unstable surfaces with eyes open, compared to both the AC and sham groups. However, there were no significant differences among the groups in terms of sway length, anteroposterior velocity, or mediolateral velocity. Our results indicate the polarity-dependent effects of bilateral cerebellar tDCS on balance functions, with enhanced stability observed only following cathodal tDCS over the right cerebellum paired with anodal tDCS over the left cerebellum. This polarity-specific modulation may have implications for developing cerebellar neuromodulation interventions for movement disorders.

Characterization of polyethylene films drawn by machine direction orientation and consequences on their photooxidation

The effect of uniaxial drawing by Machine Direction Orientation (MDO) on polyethylene films was first studied by complementary analytical methods. XRD and polarized FTIR spectroscopy revealed the transformation of the initial spherulitic structure of PE into microfibrils composed of small crystalline blocks connected by amorphous chains oriented along the drawing direction. No stress-induced crystallization was observed upon MDO processing, but the permeability to oxygen was reduced by 30 % owing to this morphology change. In a second time, the effect of photooxidation on undrawn and MDO-drawn films was studied. There was no difference in the photooxidation kinetics and stoichiometry between them. A slight reorganization of the polymer structure due to physical ageing was observed before any photooxidation, but no change in orientation occurred upon photochemical ageing. Finally, the oxygen permeability of undrawn and MDO-drawn films decreased owing to the changes brought by photooxidation, especially the formation of polar functions within the initially apolar polyethylene and the occurrence of chemicrystallization.

Dual-polarization reconfigurable metasurface for broadband vortex beam generation

Recently, reconfigurable metasurfaces integrated with adaptable devices have demonstrated exceptional dynamic controllability across various applications, garnering considerable attention. However, many reported metasurfaces, particularly those supporting dual-polarization adjustability, exhibit limited broadband electromagnetic performance. To address this limitation, we propose a dual-polarized reconfigurable intelligent surface (RIS) with a distinctive metal layer design. Our prototype, which consists of 6 × 6 units, has been experimentally validated for its broadband performance. This RIS enables simultaneous beam control, including both beam deflection and vortex beam generation, over a frequency range from 1.8 to 2.4 GHz, achieving a fractional bandwidth of 28.6% for dual-polarized waves. By expanding polarization functionality, our work provides a solution for enhancing channel capacity in communication systems, presenting promising applications in wireless communication.

Oriented Crystal Polarization Tuning Bulk Charge and Single-Site Chemical State for Exceptional Hydrogen Photo-Production.

Rapid bulk charge recombination and mediocre surface catalytic sites harshly restrict the photocatalytic activities. Herein, the aforementioned concerns are well addressed by coupling macroscopic spontaneous polarization and atomic-site engineering of CdS single-crystal nanorods for superb H2 photo-production. The oriented growth of CdS nanorods along the polar axis, vectorially superimposing substantial polar units with orderly arrangement, renders a strong polarization electric field (20.1 times enhancement), which boosts bulk charge separation with an efficiency up to 72.4% (80.4-fold). Remarkably, polarization electric field alters the chemical state of Pt single sites by orderly reducing the binding energy of Pt atom with stepwise polarization enhancement of CdS substrate, which increases the onsite electron density of Pt from 10.232 to 10.261e- and *H key intermediates, providing preponderant Volmer-Tafel/Volmer-Heyrovsky reaction pathways with significantly decreased energy barriers for H2 production. Thus, highly polarized CdS nanorods with atomically dispersed Pt sites perform an outstanding H2 space-time yield of 118.5mmol g-1 h-1 and apparent quantum efficiency of 57.7% at λ = 420nm, and a record-high H2 turnover frequency of 57798.4 h-1, being one of the best catalysts for photocatalytic H2 evolution. This work highlights the function of polarization in manipulating charge separation and catalytic reaction.

Estimation of Electric Dipole Moment by Solvatochromism, Computational Method, and Study of the Effect of Solvents by Preferential Solvation of 6 - Methoxy-4-(4-Nitro-Phenoxy Methyl)-Chromen-2-One (6mnpm).

At room temperature, the absorption and fluorescence properties of coumarin 6-Methoxy-4-(4-nitro-phenoxy methyl)-chromen-2-one (6MNPM) are investigated in pure organic solvents and a combination of acetonitrile (ACN) and tetrahydrofuran (THF). The pure solvents' influence on spectral characteristics is examined by applying theories such as Kamlet and Catalan's multiple linear regression techniques, Reichardt's microscopic solvent polarity parameter, and the Lippert-Mataga polarity function. The significant role of solute-solvent interactions in pure solvents, particularly dielectric interaction and hydrogen bonding. However, hydrogen bonding interactions dominate the contribution of dielectric interactions. The electric dipole moments of both the ground as well as excited states had been calculated using the Solvatochromic method. The value of the excited state electric dipole moment and the redshifts of the emission spectra show that the emitting singlet state has an intramolecular charge transfer (ICT) character. From Catalan's linear regression, we found that di-polarity has a much smaller influence than polarizability. By solvation study, we conclude that Tetrahydrofuran solvent is preferred over Acetonitrile.

Activation of the HMGB1-TLR4 pathway impacts the functionality of bone marrow mesenchymal stem cells and disrupts macrophage polarization in immune thrombocytopenia.

Recent evidence suggests that immune thrombocytopenia (ITP), a common bleeding disorder, is linked to an imbalance in macrophage polarization and impaired bone marrow mesenchymal stem cells (BMSCs). However, the relationship between macrophage polarization imbalance and functional defects in BMSCs, as well as the involvement of associated molecules in BMSCs' defects, is not well understood. This study aimed to investigate the regulatory effects of high mobility group protein 1 (HMGB1) on the physiological functions of BMSCs, specifically in relation to macrophage polarization imbalance. Patients with ITP showed dysregulation in monocyte/macrophage polarization and impaired BMSCs function. HMGB1 was found to have a negative impact on the ability of BMSCs to regulate the imbalance in macrophage polarization, especially when inflammatory factors are present. The MyD88-dependent pathway downstream of BMSCs was found to be significantly enhanced with HMGB1 treatment. Furthermore, treatment with toll-like receptor 4 (TLR4) inhibitors successfully restored the regulatory capacity of BMSCs in ameliorating macrophage polarization imbalance and effectively inhibited the activation of the MyD88-dependent pathway. Meanwhile, infusion of si-TLR4-BMSCs reversed HMGB1-induced platelet dysfunction and reduced over-polarization to M1-like macrophages in the ITP mouse model. Consequently, targeting the HMGB1-TLR4 pathway could be a potential approach to restore the immunoregulatory function of BMSCs.

Collective Identity and Ethical Dilemmas Among College Students in Chinese Anonymous Online Communities: Sensory Stimulation and Media Effects of Online Exposure Discourse

This paper explores the dynamics of viral social media exposure posts within anonymous online communities in China, specifically concentrating on college students. Based on theories of effervescence and collective frenzy, this research probes into the emotional triggers and functions of group polarization and social identity reconstruction in the digital sphere. Adopting a mixed-methods approach that integrates semi-structured interviews and surveys, it evaluates participants' interactions with online exposure. The anticipated findings are expected to shed light on how factors like group identity, anonymity, and virality cultivate a carnival-like ambiance in social media exposure. These posts function as instruments for mobilization, provide support for social and political causes, and act as platforms for community building and identity formation. They also offer psychological and emotional outlets, aiding users in processing and expressing personal and societal grievances. The paper aims to deepen people's understanding of how digital interactions influence collective identities and social behaviors.

Synthesis and optimization of chitosan-incorporated semisynthetic polymer/α-Fe2O3 nanoparticle hybrid polymer to explore optimal efficacy of fluorescence resonance energy transfer/charge transfer for Co(II) and Ni(II) sensing

Initially, four synthetic fluorescent polymers (SFPs) are synthesized from α-methacrylic acid and methanolacrylamide monomers carrying –C(=O)OH and –C(=O)NH subfluorophores, respectively. Among SFPs, ∼1:1 incorporation of subfluorophores in the optimum SFP3 is explored by spectroscopic analyses. Subsequently, chitosan is incorporated in SFP3 to produce five semi-synthetic fluorescent polymers (SSFPs). The maximum incorporation of chitosan in SSFP4 is supported by different spectroscopies. In SSFP4, strong electrostatic interactions among polar functionalities of chitosan and synthetic polymer favor resonance-associated charge transfer (RCT) from SSFP4-(amide) to SSFP4-(canonical). Finally, three hybrid fluorescent polymers (HFPs) are fabricated encapsulating iron-oxide nanoparticle within SSFP4. The maximum proportion of hematite (α-Fe2O3) phase in HFPs is explored by spectroscopic, magnetometric, microscopic, and light scattering studies. HFP2 shows local/RCT/fluorescence resonance energy transfer (FRET) emission at 393/460/570 nm. In HFP2, FRET, RCT, and ratiometric pH-sensing within 3.0–6.5 phenomena are explored by solvent polarity effects, time-correlated single photon counting, quantum yield measurements, alongside I431/I460 vs pH plots. RCT and FRET emissions of HFP2 are utilized for selective sensing of Co(II)/Ni(II) with limits of detection of 4.990 ppb (460 nm)/4.353 ppb (570 nm) and 45.041 ppb (428 nm)/29.617 ppb (527 nm) in organic and aqueous solutions, respectively.

COULOMB DRAG RESISTIVITY IN DOUBLE-LAYER GRAPHENE: INHOMOGENEITY EFFECTS

We investigate Coulomb drag resistivity in a double-layer system consisting of two parallel monolayer graphene sheets. In calculations, we employ the random-phase approximation to determine the polarizability functions of the graphene layers and the frequency-dependent dielectric function of the structure, taking into account inhomogeneity effects of the background dielectric. Our numerical calculations reveal that Coulomb drag resistivity in double-layer graphene systems steadily increases with increasing temperature but quickly decreases as the interlayer separation increases. The drag resistivity between the two layers in the case of an inhomogeneous background dielectric is substantially larger than that in the case of a homogeneous one. In addition, both the value and the imbalance in carrier density in the layers lead to noticeable changes in Coulomb drag resistivity in the system. Our study results are useful in graphene-based structure applications.

Electrochemical Engineering of Anode with Zincophilic Polymer Interface for Reversible Zinc Battery

AbstractAqueous rechargeable zinc‐ion batteries are emerging as green and safe energy devices owing to their high energy density and eco‐friendliness. The bottleneck is the inhomogeneous nucleation resulting in the growth of Zn dendrites and the parasitic side reactions at the anode. Herein, an electrochemical anode engineering strategy is demonstrated to curb the uncontrolled dendritic growth and side reactions. It involves the in situ generation of a solid‐electrolyte interface based on a Zn nanoparticle‐embedded poly(acrylic acid) hybrid layer (PAA‐nZn) on the anode. The homogeneously distributed polar functionalities and porous nature of the polymer regulate the uniform zinc ion flux, and the embedded zinc particle serves as nucleation sites for zinc plating. The hybrid layer reduces the nucleation overpotential and promotes instantaneous nucleation. The symmetrical cell made with PAA‐nZn@Zn has a lifecycle of &gt;860 h with a voltage gap of 28 mV. The full cell fabricated by pairing the engineered anode with α‐MnO2 cathode showed a high discharge specific capacity of 238.3 mAh g−1 at 0.2 A g−1 with a capacity retention of 81.76% after 200 cycles and a long lifecycle. The electrochemical engineering of the anode suppresses the dendritic growth and protects the anode from unwanted side reactions and passivation.

Hydrogen bonding in 2,2,2-trifluoroethanol.

2,2,2-Trifluoroethanol (TFE) is known as a membrane mimetic solvent. The IR spectrum, 1H NMR spectrum, 13C NMR spin‒lattice relaxation times (T1), and nuclear Overhauser effect (NOE) data are consistent with extensive hydrogen bonding in TFE, but do not lead to structural features of the hydrogen bonding. Hence, DFT computations were carried out. The results predict the existence of a set of H-bonded dimers and trimers. The bond lengths and dihedral angles in these complexes are obtained, together with their dissociation energies. Computations were also performed for the geometry of the two conformers of the isolated monomer. The structure of one of the dimers consists of a 7-member cyclic fragment with a free CF3CH2 side chain. One set of the trimer structures involves the OH of a third monomer H-bonding to one of the F atoms in the CF3 group of the side chain of this dimer, thereby creating three trimer isomers. A fourth trimer cluster is formed from three monomers in which three OH∙∙∙O bonds create a cyclic fragment with three CF3CH2 side chains. The high dissociation energy (with respect to three monomers) indicates the high stability of the trimer complexes. The structural features of the trimer complexes resemble the structure of a conventional liquid crystal molecule and are postulated to resemble the latter in properties and function in solution, but at a much shorter timescale because of the noncovalent bonding. This hydrogen bonding phenomenon of TFE may be related to its function as a membrane memetic solvent. Initially, IR and NMR spectroscopic methods were used. Standard procedures were followed. For the computations, a hybrid DFT method with empirical dispersion, ωB97X-D, was used. The basis set, 6-311++G**, is of triple-ζ quality, in which polarization functions and diffuse functions were added for all atoms.

Inhibition of STAT3 by 2-Methoxyestradiol suppresses M2 polarization and protumoral functions of macrophages in breast cancer

BackgroundBreast cancer metastasis remains the leading cause of cancer-related deaths in women worldwide. Infiltration of tumor-associated macrophages (TAMs) in the tumor stroma is known to be correlated with reduced overall survival. The inhibitors of TAMs are sought after for reprogramming the tumor microenvironment. Signal transducer and activator of transcription 3 (STAT3) is well known to contribute in pro-tumoral properties of TAMs. 2-Methoxyestradiol (2ME2), a potent anticancer and antiangiogenic agent, has been in clinical trials for treatment of breast cancer. Here, we investigated the potential of 2ME2 in modulating the pro-tumoral effects of TAMs in breast cancer.MethodsTHP-1-derived macrophages were polarized to macrophages with or without 2ME2. The effect of 2ME2 on macrophage surface markers and anti-inflammatory genes was determined by Western blotting, flow cytometry, immunofluorescence, qRT‒PCR. The concentration of cytokines secreted by cells was monitored by ELISA. The effect of M2 macrophages on malignant properties of breast cancer cells was determined using colony formation, wound healing, transwell, and gelatin zymography assays. An orthotopic model of breast cancer was used to determine the effect of 2ME2 on macrophage polarization and metastasis in vivo.ResultsFirst, our study found that polarization of monocytes to alternatively activated M2 macrophages is associated with the reorganization of the microtubule cytoskeleton. At lower concentrations, 2ME2 treatment depolymerized microtubules and reduced the expression of CD206 and CD163, suggesting that it inhibits the polarization of macrophages to M2 phenotype. However, the M1 polarization was not significantly affected at these concentrations. Importantly, 2ME2 inhibited the expression of several anti-inflammatory cytokines and growth factors, including CCL18, TGF-β, IL-10, FNT, arginase, CXCL12, MMP9, and VEGF-A, and hindered the metastasis-promoting effects of M2 macrophages. Concurrently, 2ME2 treatment reduced the expression of CD163 in tumors and inhibited lung metastasis in the orthotopic breast cancer model. Mechanistically, 2ME2 treatment reduced the phosphorylation and nuclear translocation of STAT3, an effect which was abrogated by colivelin.ConclusionsOur study presents novel findings on mechanism of 2ME2 from the perspective of its effects on the polarization of the TAMs via the STAT3 signaling in breast cancer. Altogether, the data supports further clinical investigation of 2ME2 and its derivatives as therapeutic agents to modulate the tumor microenvironment and immune response in breast carcinoma.

A contactless in situ EFISH method for measuring electrostatic potential profile of semiconductor/electrolyte junctions.

In photoelectrochemical cells, promising devices for directly converting solar energy into storable chemical fuels, the spatial variation of the electrostatic potential across the semiconductor-electrolyte junction is the key parameter that determines the cell performance. In principle, electric field induced second harmonic generation (EFISH) provides a contactless in situ spectroscopic tool to measure the spatial variation of electrostatic potential. However, the total second harmonic generation (SHG) signal contains the contributions of the EFISH signals of semiconductor space charge layer and the electric double layer, in addition to the SHG signal of the electrode surface. The interference of these complex quantities hinders their analysis. In this work, to understand and deconvolute their contributions to the total SHG signals, bias-dependent SHG measurements are performed on the rutile TiO2(100)-electrolyte junction as a function of light polarization and crystal azimuthal angle (angle of the incident plane relative to the crystal [001] axis). A quadratic response between SHG intensity and the applied potential is observed in both the accumulation and depletion regions of TiO2. The relative phase difference and amplitude ratio are extracted at selected azimuthal angles and light polarizations. At 0° azimuthal angle and s-in-p-out polarization, the SHG intensity minimum has the best match with the TiO2 flatband potential due to the orthogonal relative phase difference between bias-dependent and bias-independent SHG terms. We further measure the pH-dependent flatband potential and probe the photovoltage under open circuit conditions using the EFISH technique, demonstrating the capability of this contactless method for measuring electrostatic potential at semiconductor-electrolyte junctions.