Measuring the Electric Fields of Ions Captured in Crown Ethers.

Controlling reactivity with electric fields is a persistent challenge in chemistry. One approach is to tether ions at well-defined locations near a reactive center. To quantify fields arising from ions, we report crown ethers that capture metal cations as field sources and a covalently bound vibrational Stark shift probe as a field sensor. We use experiments and computations in both the gas and liquid phases to quantify the vibrational frequencies of the probe and estimate the electric fields from the captured ions. Cations, in general, blue shift the probe frequency, with effective fields estimated to vary in the range of ∼0.2-3 V/nm in the liquid phase. Comparison of the gas and liquid phase data provides insight into the effects of mutual polarization of the molecule and solvent and screening of the ion's field. These findings reveal the roles of charge, local screening, and geometry in the design of tailored electric fields.

Sweet potato (Ipomoea batatas L.) genotype selection using advanced indices and statistical models: A multi-year approach.

In Bangladesh, sweet potato holds the fourth position as a crucial carbohydrate source, trailing rice, wheat, and potato. However, locally grown sweet potato varieties often display limited stability and yield. To tackle this challenge, diverse selection methods and statistical models were utilized to pinpoint sweet potato genotypes showcasing both stability and superior yield and quality traits. In the initial two years, multiple selection methods were employed to narrow down the collections based on preferences for yield and its contributing traits. Subsequently, a multi-environment trial (MET) was conducted in the following year to pinpoint superior and stable genotypes with desirable yield and quality characteristics. An integrated approach involving the Multi-Trait Genotype Ideotype Distance Index (MGIDI), Factor Analysis and Ideotype-Design (FAI-BLUP), and Smith-Hazel Index (SH) led to the identification of 71 superior sweet potato genotypes out of a total of 351 in the initial growing season. In the subsequent season, the MGIDI selection index was applied to the 71 genotypes, resulting in the selection of 11 top-performing genotypes. This selection process was complemented by a detailed analysis of the strengths and weaknesses of the selected genotypes. In the MET, the mixed effect model, specifically the linear mixed model (LMM), identified significant genotypic and genotype-environment interaction (GEI) variances. This points to elevated heritability and selection accuracy, ultimately boosting the model's reliability. By combining the strengths of LMM and additive main effects and multiplicative interaction (AMMI), the best linear unbiased prediction (BLUP) index identified H20 as the top-performing genotype for marketable root yield (MRY), H37 for dry weight of root (DW), H8 for beta carotene (BC) and H41 for vitamin c (VC). These genotypes surpassed the overall average in the WAAS index. For simultaneous stability and high performance, the WAASBY index selected H37 for MRY, H6 for DW, H61 for BC, and H3 for VC. Finally, genotypes H3 and H20 were selected using multi-trait stability index (MTSI), as they possessed high performance and stability. Based on the selection sense, the objective has been achieved with regards to the trait MRW, which serves as a major criterion for a superior variety of sweet potato.

Visualizing partial solvation at the air-water interface.

Despite significant research, the mechanistic nuances of unusual reactivity at the air-water interface, especially in microdroplets, remain elusive. The likely contributors include electric fields and partial solvation at the interface. To reveal these intricacies, we measure the frequency shift of a well-defined azide vibrational probe at the air-water interface, while independently controlling the surface charge density by introducing surfactants. First, we establish the response of the probe in the bulk and demonstrate that it is sensitive to both electrostatics and hydrogen bonding. From interfacial spectroscopy we infer that the azide is neither fully hydrated nor in a completely aprotic dielectric environment; instead, it experiences an intermediate environment. In the presence of hydrogen bond-accepting sulphate surfactants, competition arises for interfacial water with the azide. However, the dominant influence stems from the electrostatic effect of their negative heads, resulting in a significant blue-shift. Conversely, for the positive ammonium surfactants, our data indicate a balanced interplay between electrostatics and hydrogen bonding, leading to a minimal shift in the probe. Our results demonstrate partial solvation at the interface and highlights that both hydrogen bonding and electrostatics may assist or oppose each other in polarizing a reactant, intermediate, or product at the interface, which is important for understanding and tuning interfacial reactivity.

Dissolution of cellulose in imidazolium-based double salt ionic liquids.

The dissolution of cellulose in double salt ionic liquids (DSILs) was studied in detail and compared with the dissolution in individual constituent ionic liquids (ILs). The DSILs, [C4mim](CH3CO2)xCl1-x (x is the mole fraction of the single component ILs), were synthesized using acetate and chloride salts of 1-butyl-3-methylimidazolium. These DSILs were then used for the investigation of the solubility of cellulose in the whole mole fraction range. Commercial cellulose (CC) powder, kraft pulp (KP), and prehydrolysis kraft pulp (PHKP) of jute were chosen as cellulose sources. The solubility of cellulose increased with an increasing temperature for [C4mim](CH3CO2)0.6Cl0.4 and with increasing amount of [C4mim]Cl in DSILs. The maximum solubility of CC powder was 32.8 wt% in [C4mim](CH3CO2)0.6Cl0.4 at 100 °C, while for KP and PHKP, solubilities were 30.1 and 30.5 wt%, respectively under the identical condition. Cellulose could be regenerated from the DSILs using water as an antisolvent. Structure, morphology, and thermal stability of the regenerated cellulosic materials were analyzed. DSILs could be recycled >99 % without a discernible change in structure. This work demonstrates that DSILs display enhanced solubility over ILs system and have potential as a chemical processing methodology.

Cooperative Effects Drive Water Oxidation Catalysis in Cobalt Electrocatalysts through the Destabilization of Intermediates.

A barrier to understanding the factors driving catalysis in the oxygen evolution reaction (OER) is understanding multiple overlapping redox transitions in the OER catalysts. The complexity of these transitions obscure the relationship between the coverage of adsorbates and OER kinetics, leading to an experimental challenge in measuring activity descriptors, such as binding energies, as well as adsorbate interactions, which may destabilize intermediates and modulate their binding energies. Herein, we utilize a newly designed optical spectroelectrochemistry system to measure these phenomena in order to contrast the behavior of two electrocatalysts, cobalt oxyhydroxide (CoOOH) and cobalt-iron hexacyanoferrate (cobalt-iron Prussian blue, CoFe-PB). Three distinct optical spectra are observed in each catalyst, corresponding to three separate redox transitions, the last of which we show to be active for the OER using time-resolved spectroscopy and electrochemical mass spectroscopy. By combining predictions from density functional theory with parameters obtained from electroadsorption isotherms, we demonstrate that a destabilization of catalytic intermediates occurs with increasing coverage. In CoOOH, a strong (∼0.34 eV/monolayer) destabilization of a strongly bound catalytic intermediate is observed, leading to a potential offset between the accumulation of the intermediate and measurable O2 evolution. We contrast these data to CoFe-PB, where catalytic intermediate generation and O2 evolution onset coincide due to weaker binding and destabilization (∼0.19 eV/monolayer). By considering a correlation between activation energy and binding strength, we suggest that such adsorbate driven destabilization may account for a significant fraction of the observed OER catalytic activity in both materials. Finally, we disentangle the effects of adsorbate interactions on state coverages and kinetics to show how adsorbate interactions determine the observed Tafel slopes. Crucially, the case of CoFe-PB shows that, even where interactions are weaker, adsorption remains non-Nernstian, which strongly influences the observed Tafel slope.

Impact of Intra-Operative Shock and Resuscitation on Surgical Site Infections After Trauma Laparotomy.

Background: Patients undergoing trauma laparotomy experience high rates of surgical site infection (SSI). Although intra-operative shock is a likely contributor to SSI risk, little is known about the relation between shock, intra-operative restoration of physiologic normalcy, and SSI development. Patients and Methods: A retrospective review of trauma patients who underwent emergent definitive laparotomy was performed. Using shock index and base excess at the beginning and end of laparotomy, patients were classified as normal, persistent shock, resuscitated, or new shock. Univariable and multivariable analyses were performed to identify predictors of organ/space SSI, superficial/deep SSI, and any SSI. Results: Of 1,191 included patients, 600 (50%) were categorized as no shock, 248 (21%) as resuscitated, 109 (9%) as new shock, and 236 (20%) as persistent shock, with incidence of any SSI as 51 (9%), 28 (11%), 26 (24%), and 32 (14%), respectively. These rates were similar in organ/space and superficial/deep SSIs. On multivariable analysis, resuscitated, new shock, and persistent shock were associated with increased odds of organ/space SSI (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.3-3.5; p < 0.001) and any SSI (OR, 2.0; 95% CI, 1.4-3.2; p < 0.001), but no increased risk of superficial/deep SSI (OR, 1.4; 95% CI, 0.8-2.6; p = 0.331). Conclusions: Although the trajectory of physiologic status influenced SSI, the presence of shock at any time during trauma laparotomy, regardless of restoration of physiologic normalcy, was associated with increased odds of SSI. Further investigation is warranted to determine the relation between peri-operative shock and SSI in trauma patients.

Racial and Ethnic Disparities in Operative Experience Among General Surgery Residents: A Multi-Institutional Study from the US ROPE Consortium.

OBJECTIVE: To determine the relationship between race/ethnicity and case volume among graduating surgical residents. BACKGROUND: Racial/ethnic minority individuals face barriers to entry and advancement in surgery; however, no large-scale investigations of the operative experience of racial/ethnic minority residents have been performed. METHODS: A multi-institutional retrospective analysis of the Accreditation Council for Graduate Medical Education case logs of categorical general surgery residents at 20 programs in the US Resident OPerative Experience Consortium database was performed. All residents graduating between 2010 and 2020 were included. The total, surgeon chief, surgeon junior, and teaching assistant case volumes were compared between racial/ethnic groups. RESULTS: The cohort included 1343 residents. There were 211 (15.7%) Asian, 65 (4.8%) Black, 73 (5.4%) Hispanic, 71 (5.3%) "Other" (Native American or Multiple Race), and 923 (68.7%) White residents. On adjusted analysis, Black residents performed 76 fewer total cases (95% CI, -109 to -43, P <0.001) and 69 fewer surgeon junior cases (-98 to -40, P <0.001) than White residents. Comparing adjusted total case volume by graduation year, both Black residents and White residents performed more cases over time; however, there was no difference in the rates of annual increase (10 versus 12 cases per year increase, respectively, P =0.769). Thus, differences in total case volume persisted over the study period. CONCLUSIONS: In this multi-institutional study, Black residents graduated with lower case volume than non-minority residents throughout the previous decade. Reduced operative learning opportunities may negatively impact professional advancement. Systemic interventions are needed to promote equitable operative experience and positive culture change.

Preparation of chitosan derivative and its application in papermaking.

To improve the paper strength, a number of resins and polymeric materials are being used, which is not environmental friendly and sustainable. Therefore, bio-based paper additives for the papermaking industry are essential. In this investigation, a water soluble biopolymer like carboxymethyl chitosan (CMCh) was prepared. The degree of substitution of the prepared CMCh was 2.49. The solubility of the prepared CMCh was 2.0 (w/v) % at 50 °C, and the conductivity increased with the increase of CMCh concentration in water. The prepared CMCh was applied as dry and wet strength agent of unrefined and refined softwood pulps. Both pulp increased dry and wet strength with increasing CMCh dose. An addition of 2.0 % CMCh increased dry strength by 125 % and wet strength by 293 % of unrefined pulp. On the other hand, the dry and wet tensile index of refined pulp increased from 59.48 N·m/g to 66.11 N·m/g and 2.48 N·m/g to 3.47 N·m/g, respectively, with the addition of 1.0 % CMCh. The CMCh was also used in filler modification. The precipitated calcium carbonate (PCC) modified with CMCh increased the ash content in paper with improved strength properties. The CMCh can be used in papermaking both for improving paper strength and filler retention.

Patient-Reported Outcomes Following Severe Abdominal Trauma: A Secondary Analysis of the Damage Control Laparotomy Trial.

INTRODUCTION: Little is known about patient-reported outcomes (PROs) following abdominal trauma. We hypothesized that patients undergoing definitive laparotomy (DEF) would have better PROs compared to those treated with damage control laparotomy (DCL). METHODS: The DCL Trial randomized DEF versus DCL in abdominal trauma. PROs were measured using the European Quality of Life-5 Dimensions-5 Levels (EQ-5D) questionnaire at discharge and six months postdischarge (1 = perfect health, 0 = death, and <0 = worse than death) and Posttraumatic Stress Disorder (PTSD) Checklist-Civilian. Unadjusted Bayesian analysis with a neutral prior was used to assess the posterior probability of achieving minimal clinically important difference. RESULTS: Of 39 randomized patients (21 DEF versus 18 DCL), 8 patients died (7 DEF versus 1 DCL). Of those who survived, 28 completed the EQ-5D at discharge (12 DEF versus 16 DCL) and 25 at 6 mo (12 DEF versus 13 DCL). Most patients were male (79%) with a median age of 30 (interquartile range (IQR) 21-42), suffered blunt injury (56%), and were severely injured (median injury severity score 33, IQR 21 - 42). Median EQ-5D value at discharge was 0.20 (IQR 0.06 - 0.52) DEF versus 0.31 (IQR -0.03 - 0.43) DCL, and at six months 0.51 (IQR 0.30 - 0.74) DEF versus 0.50 (IQR 0.28 - 0.84) DCL. The posterior probability of minimal clinically important difference DEF versus DCL at discharge and six months was 16% and 23%, respectively. CONCLUSIONS: Functional deficits for trauma patients persist beyond the acute setting regardless of laparotomy status. These deficits warrant longitudinal studies to better inform patients on recovery expectations.

A multi-institutional study from the US ROPE consortium examining factors associated with endocrine surgery exposure for general surgery residents.

BACKGROUND: Prior analyses of general surgery resident case logs have indicated a decline in the number of endocrine procedures performed during residency. This study aimed to identify factors contributing to the endocrine operative experience of general surgery residents and compare those who matched in endocrine surgery fellowship with those who did not. METHODS: We analyzed the case log data of graduates from 18 general surgery residency programs in the US Resident Operative Experience Consortium over an 11-year period. RESULTS: Of the 1,240 residents we included, 17 (1%) matched into endocrine surgery fellowships. Those who matched treated more total endocrine cases, including more thyroid, parathyroid, and adrenal cases, than those who did not (81 vs 37, respectively, P < .01). Program-level factors associated with increased endocrine volume included endocrine-specific rotations (+10, confidence interval 8-12, P < .01), endocrine-trained faculty (+8, confidence interval 7-10, P < .01), and program co-location with otolaryngology residency (+5, confidence interval 2 -8, P < .01) or endocrine surgery fellowship (+4, confidence interval 2-6, P < .01). Factors associated with decreased endocrine volume included bottom 50th percentile in National Institute of Health funding (-10, confidence interval -12 to -8, P < .01) and endocrine-focused otolaryngologists (-3, confidence interval -4 to -1, P < .01). CONCLUSION: Several characteristics are associated with a robust endocrine experience and pursuit of an endocrine surgery fellowship. Modifiable factors include optimizing the recruitment of dedicated endocrine surgeons and the inclusion of endocrine surgery rotations in general surgery residency.

Electro-inductive Effect Dominates Vibrational Frequency Shifts of Conjugated Probes on Gold Electrodes.

Interfacial electric fields play a critical role in electrocatalysis and are often characterized by using vibrational probes attached to an electrode surface. Understanding the physical principles dictating the impact of the applied electrode potential on the vibrational probe frequency is important. Herein, a comparative study is performed for two molecular probes attached to a gold electrode. Both probes contain a nitrile (CN) group, but 4-mercaptobenzonitrile (4-MBN) exhibits continuous conjugation from the electrode through the nitrile group, whereas this conjugation is interrupted for 2-(4-mercaptophenyl)acetonitrile (4-MPCN). Periodic density functional theory calculations predict that the CN vibrational frequency shift of the 4-MBN system is dominated by induction, which is a through-bond polarization effect, leading to a strong potential dependence that does not depend significantly on the orientation of the CN bond relative to the surface. In contrast, the CN vibrational frequency shift of the 4-MPCN system is influenced less by induction and more by through-space electric field effects, leading to a weaker potential dependence and a greater orientation dependence. These theoretical predictions were confirmed by surface-enhanced Raman spectroscopy experiments. Balancing through-bond and through-space electrostatic effects may assist in the fundamental understanding and design of electrocatalytic systems.

Understanding the Immunopathology of HTLV-1-Associated Adult T-Cell Leukemia/Lymphoma: A Comprehensive Review.

Human T-cell leukemia virus type-1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATL). HTLV-1 carriers have a lifelong asymptomatic balance between infected cells and host antiviral immunity; however, 5-10% of carriers lose this balance and develop ATL. Coinfection with Strongyloides promotes ATL development, suggesting that the immunological status of infected individuals is a determinant of HTLV-1 pathogenicity. As CD4+ T cells play a central role in host immunity, the deregulation of their function and differentiation via HTLV-1 promotes the immune evasion of infected T cells. During ATL development, the accumulation of genetic and epigenetic alterations in key host immunity-related genes further disturbs the immunological balance. Various approaches are available for treating these abnormalities; however, hematopoietic stem cell transplantation is currently the only treatment with the potential to cure ATL. The patient's immune state may contribute to the treatment outcome. Additionally, the activity of the anti-CC chemokine receptor 4 antibody, mogamulizumab, depends on immune function, including antibody-dependent cytotoxicity. In this comprehensive review, we summarize the immunopathogenesis of HTLV-1 infection in ATL and discuss the clinical findings that should be considered when developing treatment strategies for ATL.

Phenol as a Tethering Group to Gold Surfaces: Stark Response and Comparison to Benzenethiol.

Understanding the adsorption of organic molecules on metals is important in numerous areas of surface science, including electrocatalysis, electrosynthesis, and biosensing. While thiols are commonly used to tether organic molecules on metals, it is desirable to broaden the range of anchoring groups. In this study, we use a combined spectroelectrochemical and computational approach to demonstrate the adsorption of 4-cyanophenols (CPs) on polycrystalline gold. Using the nitrile stretching vibration as a marker, we confirm the adsorption of CP on the gold electrode and compare our results with those obtained for the thiol counterpart, 4-mercaptobenzonitirle (MBN). Our results reveal that CP adsorbs on the gold electrode via the OH linker, as evidenced by the similarity in the direction and magnitude of the nitrite Stark shifts for CP and MBN. This finding paves the way for exploring new approaches to modify electrode surfaces for controlled reactivity. Furthermore, it highlights adsorption on metals as an important step in the electroreactivity of phenols.

Inferring the Energetics of CO2-Aniline Adduct Formation from Vibrational Spectroscopy.

Control of atmospheric CO2 is an important contemporary scientific and engineering challenge. Toward this goal, the reaction of CO2 with amines to form carbamate bonds is an established method for CO2 capture. However, controllable reversal of this reaction remains difficult and requires tuning the energetics of the carbamate bond. Through IR spectroscopy, we show that a characteristic frequency observed upon carbamate formation varies as a function of the substituent's Hammett parameter for a family of para-substituted anilines. We present computational evidence that the vibrational frequency of the adducted CO2 serves as a predictor of the energy of formation of the carbamate. Electron donating groups typically enhance the driving force of carbamate formation by transferring more charge to the adducted CO2 and thus increasing the occupancy of the antibonding orbital in the carbon-oxygen bonds. Increased occupancy of the antibonding orbital within adducted CO2 indicates a weaker bond, leading to a red-shift in the characteristic carbamate frequency. Our work serves the large field of CO2 capture research where spectroscopic observables, such as IR frequencies, are more easily obtainable and can stand in as a descriptor of driving forces.

Inductive Effect Alone Cannot Explain Lewis Adduct Formation and Dissociation at Electrode Interfaces.

Understanding breaking and formation of Lewis bonds at an electrified interface is relevant to a large range of phenomena, including electrocatalysis and electroadsorption. The complexities of interfacial environments and associated reactions often impede a systematic understanding of this type of bond at interfaces. To address this challenge, we report the creation of a main group classic Lewis acid-base adduct on an electrode surface and its behavior under varying electrode potentials. The Lewis base is a self-assembled monolayer of mercaptopyridine and the Lewis acid is BF3, forming a Lewis bond between nitrogen and boron. The bond is stable at positive potentials but cleaves at potentials more negative of approximately -0.3 V vs Ag/AgCl without an associated current. We also show that if the Lewis acid BF3 is supplied from a reservoir of Li+BF4- electrolyte, the cleavage is completely reversible. We propose that the N-B Lewis bond is affected both by the field-induced intramolecular polarization (electroinduction) and by the ionic structures and ionic equilibria near the electrode. Our results indicate that the second effect is responsible for the Lewis bond cleavage at negative potentials. This work is relevant to understanding the fundamentals of electrocatalytic and electroadsorption processes.

Polarizable Anionic Sublattices Can Screen Molecular Dipoles in Noncentrosymmetric Inorganic-Organic Hybrids.

We report the growth and photophysical characterization of two polar hybrid lead halide phases, methylenedianiline lead iodide and bromide, (MDA)Pb2I6 and (MDA)Pb2Br6, respectively. The phases crystallize in noncentrosymmetric space group Fdd2, which produces a highly oriented molecular dipole moment that gives rise to second harmonic generation (SHG) upon excitation at 1064 nm. While both compositions are isostructural, the size dependence of the SHG signal suggests that the bromide exhibits a stronger phase-matching response whereas the iodide exhibits a significantly weaker non-phase-matching signal. Similarly, fluorescence from (MDA)Pb2Br6 is observed around 630 nm below 75 K whereas only very weak luminescence from (MDA)Pb2I6 can be seen. We attribute the contrasting optical properties to differences in the character of the halide sublattice and postulate that the increased polarizability of the iodide ions acts to screen the local dipole moment, effectively reducing the local electric field in the crystals.

Disparities in the Operative Experience Between Female and Male General Surgery Residents: A Multi-institutional Study From the US ROPE Consortium.

OBJECTIVE: To examine differences in resident operative experience between male and female general surgery residents. BACKGROUND: Despite increasing female representation in surgery, sex and gender disparities in residency experience continue to exist. The operative volume of male and female general surgery residents has not been compared on a multi-institutional level. METHODS: Demographic characteristics and case logs were obtained for categorical general surgery graduates between 2010 and 2020 from the US Resident OPerative Experience Consortium database. Univariable, multivariable, and linear regression analyses were performed to compare differences in operative experience between male and female residents. RESULTS: There were 1343 graduates from 20 Accreditation Council for Graduate Medical Education-accredited programs, and 476 (35%) were females. There were no differences in age, race/ethnicity, or proportion pursuing fellowship between groups. Female graduates were less likely to be high-volume residents (27% vs 36%, P < 0.01). On univariable analysis, female graduates performed fewer total cases than male graduates (1140 vs 1177, P < 0.01), largely due to a diminished surgeon junior experience (829 vs 863, P < 0.01). On adjusted multivariable analysis, female sex was negatively associated with being a high-volume resident (OR = 0.74, 95% CI: 0.56 to 0.98, P = 0.03). Over the 11-year study period, the annual total number of cases increased significantly for both groups, but female graduates (+16 cases/year) outpaced male graduates (+13 cases/year, P = 0.02). CONCLUSIONS: Female general surgery graduates performed significantly fewer cases than male graduates. Reassuringly, this gap in operative experience may be narrowing. Further interventions are warranted to promote equitable training opportunities that support and engage female residents.

Distinguishing between the Electrostatic Effects and Explicit Ion Interactions in a Stark Probe.

Vibrational Stark probes are incisive tools for measuring local electric fields in a wide range of chemical environments. The interpretation of the frequency shift often gets complicated due to the specific interactions of the probe, such as hydrogen bonding and Lewis bonding. Therefore, it is important to distinguish between the pure electrostatic response and the response due to such specific interactions. Here we report a molecular system that is sensitive to both the Stark effect from a single ion and the explicit Lewis bonding of ions with the probe. The molecule consists of a crown ether with an appended benzonitrile. The crown captures cations of various charges, and the electric field from the ions is sensed by the benzonitrile probe. Additionally, the lone pair of the benzonitrile can engage in Lewis interactions with some of the ions by donating partial charge density to the ions. Our system exhibits both of these effects and therefore is a suitable test bed for distinguishing between the pure electrostatic and the Lewis interactions. Our computational results show that the electrostatic influence of the ion is operative at large distances, while the Lewis interaction becomes important only within distances that permit orbital overlap. Our results may be useful for using the nitrile probe for measuring electrostatic and coordination effects in complex ionic environments such as the electrode-electrolyte interfaces.

Direct Determination of Plasmon Enhancement Factor and Penetration Depths in Surface Enhanced IR Absorption Spectroscopy.

Surface Enhanced Infrared Absorption Spectroscopy (SEIRAS) is a powerful tool for studying a wide range of surface and electrochemical phenomena. For most electrochemical experiments the evanescent field of an IR beam partially penetrates through a thin metal electrode deposited on top of an attenuated total reflection (ATR) crystal to interact with molecules of interest. Despite its success, a major problem that complicates quantitative interpretation of the spectra from this method is the ambiguity of the enhancement factor due to plasmon effects in metals. We developed a systematic method for measuring this, which relies upon independent determination of surface coverage by Coulometry of a surface-bound redox-active species. Following that, we measure the SEIRAS spectrum of the surface bound species, and from the knowledge of surface coverage, retrieve the effective molar absorptivity, εSEIRAS. Comparing this to the independently determined bulk molar absorptivity leads us to the enhancement factor f = εSEIRAS/εbulk. We report enhancement factors in excess of 1000 for the C-H stretches of surface bound ferrocene molecules. We additionally developed a methodical approach to measure the penetration depth of the evanescent field from the metal electrode into a thin film. Such systematic measure of the enhancement factor and penetration depth will help SEIRAS advance from a qualitative to a more quantitative method.