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OBJECTIVE. The purpose of this article is to review important imaging and clinical features to help elucidate causes of lymphadenopathy in patients with HIV infection. CONCLUSION. HIV lymphadenopathy has various causes generally categorized as inflammatory or reactive, such as immune reconstitution syndrome; infectious, such as tuberculous and nontuberculous mycobacterial infections and HIV infection itself; and neoplastic, such as lymphoma, Kaposi sarcoma, and Castleman disease. It is important to consider patients' demographic characteristics, clinical presentations, CD4 lymphocyte counts, and radiologic features to identify likely causes of lymphadenopathy.

Psychology as a science has focussed on internal landscapes at the expense of external ones, a fact that becomes increasingly problematic as we struggle to accept and respond to the climate crisis and its psychoterratic sequelae. This paper, written at the time of the 2019/2020 summer bushfires in Australia, takes inspiration from the Romantic Science of von Humboldt to document our affective response to our natural environment. We aimed, through a method of Flaneurie, to focus and respond and in doing so advocate for this kind of meandering as psychogeographic research. We were inspired also, in presenting our findings, by contemporary post-qualitative methodology, weaving together our observation and introspection in bricolage, to access knowledge beyond the nosology of presumptions, codes and themes. This paper links mental health and well-being to the natural environment, today a political objective. Showing that the human-nature relationship has crucial leverage for the subjects psyche and thus is highly relevant for psychology and psychological science.

The role of gastroesophageal reflux disease (GERD) in the aetiology of laryngopharyngeal reflux (LPR) is poorly understood and remains a controversial issue. The 24-hour impedance monitoring has shown promise in the evaluation of LPR but is problematic in pharyngeal recording. We have shown the utility of scintigraphic studies in the detection of LPR and lung aspiration of refluxate. Correlative studies were obtained in patients with a strong history of LPR and severe GERD.A highly selected sequential cohort of patients with a high pre-test probability of LPR/severe GERD who had failed maximal medical therapy were evaluated with 24-hour impedance/pH, manometry and scintigraphic reflux studies.The study group comprised 34 patients (15 M, 19 F) with a mean age of 56 years (range: 28-80 years). The majority had LPR symptoms (mainly cough) in 31 and severe GERD in 3. Impedance bolus clearance and pH studies were abnormal in all patients in the upright and supine position. A high rate of non-acid GERD was detected by impedance monitoring. LOS tone and ineffective oesophageal clearance were found in the majority of patients. Scintigraphic studies showed strong correlations with impedance, pH and manometric abnormalities, with 10 patients showing pulmonary aspiration.Scintigraphic studies appear to be a good screening test for LPR and pulmonary aspiration as there is direct visualisation of tracer at these sites. Impedance studies highlight the importance of non-acidic reflux and bolus clearance in the causation of cough and may allow the development of a risk profile for pulmonary aspiration of refluxate.Laringofarengeal reflü (LFR) etiyolojisinde Gastroözofageal Reflü hastalığının (GÖRH) rolü tam olarak anlaşılamamıştır ve bu durum tartışmalı bir konu olmaya devam etmektedir. Yirmi dört saatlik empedans monitörizasyonu LFR’nin değerlendirilmesinde umut vaatetmektedir, ancak faringeal kayıtlamada sorun yaşanmaktadır. Biz, LFR’nin ve reflünün akciğer aspirasyonunun saptanmasında sintigrafik çalışmaların yararını göstermiştik. Şiddetli LFR ve GÖRH öyküsü olan hastalarda korelasyon çalışmaları yapılmıştır.Maksimum medikal tedaviye yanıt vermeyen ve ön testte LFR/şiddetli GÖRH olasılığı yüksek saptanan seçilmiş bir hasta grubu; 24 saatlik empedans/pH monitörizasyonu, manometri ve sintigrafik reflü çalışmaları ile değerlendirildi.Çalışma grubu, 15’i erkek, 19’u kadın olmak üzere 34 hastadan oluşmaktaydı ve yaş ortalaması 56 (28-80) idi. Hastaların 31’inde LFR semptomları (çoğunlukla öksürük) ve 3’ünde şiddetli GÖRH semptomları vardı. Empedans bolus klirensi ve pH çalışmaları, ayakta ve sırtüstü pozisyonda tüm hastalarda anormaldi. Empedans monitörizasyon ile yüksek oranda asidik olmayan GÖRH saptandı. Hastaların çoğunda düşük özofageal sfinkter tonusu ve inefektif özofageal klirens saptandı. Sintigrafik çalışmalar pulmoner aspirasyon gelişen 10 hastada; empedans, pH ve manometrideki anormalliklerle yüksek korelasyon gösterdi.Sintigrafik çalışmalar, LFR ve pulmoner aspirasyon için iyi bir tarama testi gibi görünmektedir, çünkü bu bölgelerde tracerin doğrudan gösterilmesi mümkündür. Empedans çalışmaları, öksürüğün nedeni olarak asidik olmayan reflü ve bolus klirensinin önemini vurgulamaktadır ve reflünün pulmoner aspirasyonu için bir risk profilinin geliştirilmesinde kullanılabilir.

Pulmonary adenomyomas are rare adenomyomatous hamartomas. In the few cases described in the literature, these benign tumors are encapsulated by lung parenchyma. We describe a case of a 59 year-old woman with acetylcholine receptor antibody-negative myasthenia gravis and a right cardiophrenic mass initially thought to be a thymoma. Histopathology surprisingly revealed a pulmonary adenomyoma which involved the mediastinal fat at the cardiophrenic angle. Keywords: Pulmonary adenomyoma, Harmatoma, Adenofibroma, Solitary fibrous tumor, Myasthenia gravis, Thymoma

Diaphragmatic dysfunction is a potential cause of dyspnea that can lead to significant morbidity. The purpose of this review article is to provide readers with the essentials for performing diaphragm ultrasonography, image interpretation, and the technical limitations one needs to be aware of. Diaphragm ultrasonography is simple to perform and has proven to be an accurate and safe bedside modality, overcoming many of the traditional limitations of fluoroscopy.

Synopsis The term long COVID was coined by patients to describe the long-term consequences of COVID-19. One year into the pandemic, it was clear that all patients—those hospitalized with COVID-19 a...

Gastroesophageal reflux disease (GERD) is a common and growing problem in most western countries. It may present with the typical symptoms of heartburn and regurgitation or with the effects of extra-esophageal disease. We have developed and validated a scintigraphic test that evaluates reflux at both sites in patients at high risk of laryngopharyngeal reflux and lung aspiration. We hypothesized that the test may be able to separate physiologic reflux from pathological reflux and examined this possibility in normal asymptomatic volunteers. Asymptomatic volunteers were screened with the Belafsky reflux symptom index (RSI) and entered into the trial if scores were less than 13. (99m)Tc Phytate was ingested orally and dynamic studies from the pharynx to the stomach were obtained while upright and supine. A delayed study of the thorax was also obtained for lung aspiration of refluxate. Studies were semi-quantitated graphically as time-activity curves. A total of 25 volunteers were studied (13 M, 12 F) with a mean age of 57.5 yr (Range 40-85 yr). None gave a history of heartburn or regurgitation. Mean RSI was 4.1 (range 0-10). Testing showed upright gastroesophageal reflux to the mid-upper esophagus without pharyngeal contamination in 32%. None of the subjects showed supine reflux or lung aspiration. This result corresponds well with intraluminal impedance/pH monitoring in normal volunteers. The scintigraphic reflux test gives similar results to standard intraluminal impedance/pH studies in normal volunteers. A significant proportion of asymptomatic volunteers demonstrate upright reflux only.

While Le Corbusier and Walter Gropius were indeed enormously influential in shaping modern architecture, noteworthy designs being done today prove that the International Style is no longer dominant.

The hype around artificial intelligence (AI) in radiology continues unabated, despite the fact that the exact role AI will play in future radiology practice remains undefined. Nevertheless, education of the radiologists of the future is ongoing and needs to account for the uncertainty of this new technology. Radiology residency training has evolved even before the recent advent of imaging AI. Yet radiology residents and fellows will likely one day experience the benefits of an AI-enabled clinical training. This will offer them a customized learning experience and the ability to analyze large quantities of data about their progress in residency, with substantially less manual effort than is currently required. Additionally, they will need to learn how to interact with AI tools in clinical practice and, more importantly, understand how to evaluate AI outputs in a critical fashion as yet another piece of information contributing to the interpretation of an imaging examination. Although the exact role AI will play in the future practice of radiology remains undefined, it will surely be integrated into the education of future radiologists.

Students in a second semester general chemistry course used quantum chemical calculations to investigate and reinforce general chemistry concepts. Students explored the isomers of hypochlorous acid, made predictions of miscibility via dipole moments calculated from ab-initio means, experimentally validated/disqualified their miscibility predictions, and used molecular models to visualize intermolecular attraction forces between various compounds. Student responses in pre-/post-exercise assessments show evidence of student learning. Responses in pre-/post-exercise surveys showed an increase in student understanding of basic concepts and of the importance of quantum mechanics in common general chemistry topics.

Malingering is the “intentional production of false or grossly exaggerated physical or psychological symptoms, motivated by external incentives.” Malingering is difficult to identify and a challenge for physicians to manage. There are innumerable incentives for malingering, including financial gain, housing, and controlled substances. Although there is no definitive way to identify malingering, clues that suggest malingering include inconsistencies in history and exam, discrepancies among collateral informants, and the results of neuropsychological testing. By recognizing how malingering may be a rational, adaptive choice for patients to address their needs, psychiatrists can preserve the doctor-patient relationship and build an alliance to achieve the patient’s goals in a more productive manner. Pitfalls for clinicians treating malingering patients include burnout, aversive countertransference reactions, and inadequate treatment of comorbid medical or psychiatric conditions. Psychiatrists must also be attentive to appropriate documentation and personal safety. The long-term prognosis of malingering patients is not well understood. This review contains 5 figures, 7 tables, and 95 references. Key words: malingering, external incentive, forensic psychiatry, factitious disorder, antisocial personality disorder, countertransference, confrontation

The purpose of this article is to review the high-resolution CT characteristics of individual obstructive and restrictive chronic lung allograft dysfunction (CLAD) phenotypes to aid in making accurate diagnoses and guiding treatment.Long-term survival and function after lung transplant are considerably worse compared with after other organ transplants. CLAD is implicated as a major limiting factor for long-term graft viability. Historically thought to be a single entity, bronchiolitis obliterans syndrome, CLAD is actually a heterogeneous group of disorders with distinct subtypes.

Background: Thromboelastography (TEG) has been utilized for the guidance of blood component therapy (BCT). We aimed to investigate the association between emergent TEG-guided BCT and clinical outcomes in patients with traumatic abdominal solid organ (liver and/or spleen) injuries. Methods: A single center retrospective study of patients who sustained traumatic liver and/or spleen injuries receiving emergent BCT was conducted. TEG was ordered in all these patients. Patient demographics, general injury information, outcomes, BCT, and TEG parameters were analyzed and compared in patients receiving TEG-guided BCT versus those without. Results: A total of 166 patients were enrolled, of whom 52% (86/166) received TEG-guided BCT. A mortality of 12% was noted among patients with TEG-guided BCT when compared with 19% of mortality in patients with non-TEG-guided BCT (P > 0.05). An average of 4 units of packed red blood cell (PRBC) was received in patients with TEG-guided BCT when compared to an average of 9 units of PRBC received in non-TEG-guided BCT patients (P < 0.01). A longer hospital length of stay (LOS, 19 ± 16 days) was found among non-TEG-guided BCT patients when compared to the TEG-guided BCT group (14 ± 12 days, P < 0.05). TEG-guided BCT showed as an independent factor associated with hospital LOS after other variables were adjusted (coefficiency: 5.44, 95% confidence interval: 0.69 - 10.18). Conclusions: Traumatic abdominal solid organ injury patients receiving blood transfusions might benefit from TEG-guided BCT as indicated by less blood products needed and less hospitalization stay among the cohort. J Clin Med Res. 2017;9(5):433-438 doi: https://doi.org/10.14740/jocmr3005w

Systematic density functional theory calculations that treat the strong on-site 3d electron–electron interactions on iron via a Hubbard Ueff = 3.0 eV and the van der Waals (vdW) interactions between the substrate and adsorbate within the vdW-DF framework are employed to study the adsorption of the iron porphyrin (FeP) molecule to the Pt(111) surface. The more accurate vdW-DF-optPBE and vdW-DF-optB88 functionals found the same binding site to be the most stable and yielded binding energies that were within ∼20% of each other, whereas the binding energies computed with the vdW-DF-revPBE functional were substantially weaker. This work highlights the importance of vdW interactions for organometallic molecules chemisorbed to transition metal surfaces. The stability of the binding sites was found to depend upon the number of Fe–Pt and C–Pt bonds that were formed. Whereas in the gas phase the most stable spin state of FeP is the intermediate spin S = 1 state, the high spin S = 2 state is preferred for the FeP–Pt...

Students in an upper-level physical chemistry course used a polarimeter to measure the molar optical rotation of different optically active amino acids to confirm the Clough, Lutz, and Jirgensons (CLJ) rule. This rule states that an amino acid is in the l-configuration if the molar optical rotation becomes more positive upon the addition of acid or the acid is of the d-configuration if the optical rotation becomes more negative in an acidified solution. Students demonstrated this rule for known configurations of amino acids and then applied this rule to determine the configuration of an amino acid with an unknown configuration.

Purpose Human metapneumovirus has been increasingly identified as a cause of lower respiratory tract infection in adults worldwide. The CT imaging features of human metapneumovirus in adults have not been characterized. The purpose of this paper is to determine the imaging features of human metapneumovirus and to compare them with features of other viruses. Methods Two clinicians retrospectively reviewed the medical records of 104 adults with lower respiratory tract infection due to human metapneumovirus at four hospitals in the northeast USA over 32 months. CT images were evaluated by two chest radiologists for airspace consolidation, bronchiectasis, bronchial wall thickening, ground-glass opacities, pleural effusion and tree-in-bud opacities and the dominant imaging pattern. Results for human metapneumovirus were compared with results previously reported for other viruses. Results Human metapneumovirus predominantly caused an airway-centric pattern (71-81/104, 68-77%) of infection characterized by bronchial wall thickening, tree-in-bud opacities, peri-bronchial consolidation and/or peri-bronchial ground-glass opacities. The airway-centric pattern has been previously reported with other paramyxoviridae (parainfluenza virus and respiratory syncytial virus). However, human metapneumovirus was significantly more likely (p = 0.03-0.001) to cause bronchopneumonia (46-55%) than parainfluenza virus (17%) or respiratory syncytial virus (21%). Follow-up CT in 41 (39%) patients with hMPV revealed resolution of findings in 38/41 (91%). Conclusion The paramyxoviridae, including human metapneumovirus, are known to have a propensity to infect ciliated respiratory cells and we have demonstrated this leads to a propensity to cause bronchitis, bronchiolitis and bronchopneumonia on CT scans. Of these, human metapneumovirus is most likely to cause bronchopneumonia. Healthcare providers should consider human metapneumovirus as a cause of pneumonia on chest CT.

Peripheral limb ischaemia and gangrene are devastating complications of pneumococcal sepsis. We report a 43-year-old professional pianist who presented with early sepsis and rapid development of this syndrome. No vasopressor medication was ever administered. We urgently reviewed the medical literature on a range of therapies recommended by consulting teams, to ensure he received optimal care. Based on our review and on feedback from the patient himself, we gained valuable insights into this illness and the merits of selected treatment options. His fingers ultimately recovered their function, intact, although several toes were later amputated. More recently published reviews postulate that imbalances in coagulation factors and natural anticoagulants occur as a result of disseminated intravascular coagulopathy and ‘shock liver’ in the sepsis syndrome, leading to microcirculatory thromboses. We submit this report as we believe it supports this hypothesis and adds further valuable information. We hope our observations will assist other critical care clinicians confronting this serious condition.

Background Counseling to reduce access to lethal means such as firearms and medications is recommended for suicidal adults but does not routinely occur. We developed the Web-based Lock to Live (L2L) decision aid to help suicidal adults and their families choose options for safer home storage. Objective This study aimed to test the feasibility and acceptability of L2L among suicidal adults in emergency departments (EDs). Methods At 4 EDs, we enrolled participants (English-speaking, community-dwelling, suicidal adults) in a pilot randomized controlled trial. Participants were randomized in a 13:7 ratio to L2L or control (website with general suicide prevention information) groups and received a 1-week follow-up telephone call. Results Baseline characteristics were similar between the intervention (n=33) and control (n=16) groups. At baseline, many participants reported having access to firearms (33/49, 67%), medications (46/49, 94%), or both (29/49, 59%). Participants viewed L2L for a median of 6 min (IQR 4-10 min). L2L also had very high acceptability; almost all participants reported that they would recommend it to someone in the same situation, that the options felt realistic, and that L2L was respectful of values about firearms. In an exploratory analysis of this pilot trial, more participants in the L2L group reported reduced firearm access at follow-up, although the differences were not statistically significant. Conclusions The L2L decision aid appears feasible and acceptable for use among adults with suicide risk and may be a useful adjunct to lethal means counseling and other suicide prevention interventions. Future large-scale studies are needed to determine the effect on home access to lethal means. Trial Registration ClinicalTrials.gov NCT03478501; https://clinicaltrials.gov/ct2/show/NCT03478501

BACKGROUND Counseling to reduce access to lethal means such as firearms and medications is recommended for suicidal adults but does not routinely occur. We developed the Web-based Lock to Live (L2L) decision aid to help suicidal adults and their families choose options for safer home storage. OBJECTIVE This study aimed to test the feasibility and acceptability of L2L among suicidal adults in emergency departments (EDs). METHODS At 4 EDs, we enrolled participants (English-speaking, community-dwelling, suicidal adults) in a pilot randomized controlled trial. Participants were randomized in a 13:7 ratio to L2L or control (website with general suicide prevention information) groups and received a 1-week follow-up telephone call. RESULTS Baseline characteristics were similar between the intervention (n=33) and control (n=16) groups. At baseline, many participants reported having access to firearms (33/49, 67%), medications (46/49, 94%), or both (29/49, 59%). Participants viewed L2L for a median of 6 min (IQR 4-10 min). L2L also had very high acceptability; almost all participants reported that they would recommend it to someone in the same situation, that the options felt realistic, and that L2L was respectful of values about firearms. In an exploratory analysis of this pilot trial, more participants in the L2L group reported reduced firearm access at follow-up, although the differences were not statistically significant. CONCLUSIONS The L2L decision aid appears feasible and acceptable for use among adults with suicide risk and may be a useful adjunct to lethal means counseling and other suicide prevention interventions. Future large-scale studies are needed to determine the effect on home access to lethal means. CLINICALTRIAL ClinicalTrials.gov NCT03478501; https://clinicaltrials.gov/ct2/show/NCT03478501

Cardiac chamber enlargement is important in the prediction of morbidity and mortality for a multitude of cardiovascular processes. Although non–electrocardiographically (ECG) gated multidetector CT is a commonly used cross-sectional imaging modality to evaluate a litany of cardiothoracic processes, a standardized method for evaluating and reporting cardiac chamber size does not exist. This has led to heterogeneity in the reporting of cardiac enlargement at routine multidetector CT with most readers often using gestalt assessment and the term cardiomegaly, which does not implicate the chamber or chambers that are enlarged. The purpose of this review article is to highlight advantages and limitations of several techniques used to assess cardiac chamber size at non–ECG-gated multidetector CT and to provide readers with reproducible and rapid measurements to determine if cardiac chamber size is present. The long-term aim would be to promote discussions between radiologists and institutions that would result in improved accuracy and decreased variability when commenting on cardiac chamber size. © RSNA, 2019

Chromatographic retention factors (k) and mass spectral fragmentation patterns of per- and polyfluoroalkyl substances (PFASs) were determined using the optimized parameters in liquid chromatography with tandem high-resolution mass spectrometry (LC-HRMS) analysis. Characteristic fragment ions obtained at various collision energies (MS2 fragmentation) were used to determine the structures of newly discovered (emerging) PFASs detected from industrial effluent and surface water samples. Moreover, COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) derived octanol-water partition coefficients (Kow), along with mean isotropic polarizabilities calculated from Density Functional Theory (DFT), of known PFASs were plotted against their experimental k values (kexp) to obtain a multivariable regression model that can be used to predict k values of unknown PFASs. The k values of different structural isomers of unknown PFASs were calculated and compared to kexp. The predicted k value for the isomer that matches the MS2 fragmentation observed was found to be within 4.2 % of kexp. This study demonstrates the applicability of an approach that combines the observed MS2 fragmentation patterns and k values, together with computationally-derived log Kow and polarizabilities, in assigning the structures of unknown PFASs at environmentally relevant conditions when no reference standards are available.

First-principles calculations reveal that upon adsorption to the Cu(111) surface, the C–C single bonds within the p-benzoquinonemonoimine zwitterion (ZI) contract by about 6%. A detailed analysis reveals that the bond shortening is primarily a result of backdonation from Cu orbitals of s and d symmetry to the lowest unoccupied orbital (LUMO) of the ZI. This LUMO is π*-antibonding across the molecule and π-bonding across the C–C bond that shortens. We illustrate that the level alignment between the Fermi level of the surface and the frontier molecular orbitals of the ZI, the topology of the LUMO, and the distance between the substrate and the adsorbate are important factors enabling bond strengthening via backdonation. An extended transition state–natural orbitals for chemical valence (ETS-NOCV) analysis is applied to molecular models for this system, and it confirms that the surface → LUMO backdonation on Cu(111) is larger than on Ag(111) and Au(111).

We report a combined experimental and theoretical study of the adsorption and assembly of a nitrogen–boron-containing heterocycle, 1,2-dihydro-1,2-azaborine, on Au(111) and Cu(111). Despite the inherent molecular dipole moment, the self-assembly behavior is found to be highly surface dependent, with isolated molecules prevalent on Cu(111) and discrete (“magic”) clusters on Au(111). The ability to form clusters of a particular size can be understood in terms of a balance between attractive intermolecular interactions, including directional B–H···H–N dihydrogen bonding, and repulsive forces from Coulombic interactions between the charged molecules dictated by differences in the charge transfer and Pauli repulsion between the adsorbate and the surface. This work highlights the importance of metal–molecule charge transfer in the adsorption and assembly of dipolar molecules on surfaces and demonstrates that their surface-bound properties cannot be predicted a priori from gas-phase dipole moments alone.

Our institution has developed a mini-course program within the diagnostic radiology elective curriculum that promotes active learning, using patient cases specifically tailored to students' future specialties. The purpose of this study is to evaluate the effectiveness of this mini-course on medical student knowledge of imaging appropriateness and attitude toward radiologist consultation.During each month-long radiology elective course, students were divided into teams of up to four students based on their specialty interest and assigned recent patient cases with imaging findings relevant to their specialties. The students researched their customized patient cases, integrated pertinent clinical and imaging findings, and presented their findings in a final preceptor-led session. A five-point Likert-type item preprogram and postprogram survey assessing knowledge of imaging appropriateness and attitude toward radiologist consultation was sent to the enrolled medical students.Out of 36 medical students, 33 (92%) completed the preprogram survey and 31 (86%) completed the postprogram survey. Students reported improved confidence in knowledge of imaging appropriateness, such as indications for intravenous contrast (p0.0005) and oral contrast (p0.0005). Furthermore, students reported an improved understanding of how to utilize radiologists (p0.005) and how to provide pertinent clinical historical information when requesting a radiology exam (p0.0005). Students reported that researching the patient's historical and clinical information in conjunction with the radiology images made them more invested in the case.Assigning customized patient cases to medical students on diagnostic radiology elective, tailored to their future specialties, is an effective and active way to teach imaging appropriateness and to improve attitudes toward radiologist consultation.

The adsorption and subsequent electrooxidative polymerization of ferriprotoporphyrin IX chloride (hemin; FePPCl) was investigated on highly ordered pyrolytic graphite, glassy carbon, and polycrystalline Pt electrodes using electrochemical atomic force microscopy, first-principles calculations, and cyclic voltammetry. Hemin was shown to readily adsorb to all three surfaces; however, it was more continuous over the carbon surfaces compared to the Pt surface. This disparity in adsorption appears to be a major contributing factor to differences observed between the electrodes following hemin electropolymerization. Despite differences in roughness and morphology, hemin polymerized as a continuous layer over each electrode surface. Periodic density functional theory calculations were used to model FePP (without Cl) on both the Pt(111) and graphite surfaces using the vdW-DF-optPBE functional to account for the dispersion interactions. Our calculations suggest that the FePP molecule chemisorbs to the Pt surface while at the same time exhibiting intramolecular hydrogen bonding between the carboxylic acid groups, which are extended away from the surface. In contrast to FePP-Pt chemisorption, FePP was found to physisorb to graphite. The preferred spin state upon adsorption was found to be S = 2 on Pt(111), whereas on graphite, the high and intermediate spin states were nearly isoenergetic. Additionally, gas-phase calculations suggest that much of the surface roughness observed microscopically for the polymerized porphyrin layer may originate from the nonparallel stacking of porphyrin molecules, which interact with each other by forming four intermolecular hydrogen bonds and through dispersion interactions between the stacked porphyrin rings. Regardless of polymer thickness, the underlying electrode appears to be able to participate in at least some redox processes. This was observed for the hemin-polymerized Pt electrode using the 2H