Development of Two-Dimensional Electronic-Vibrational Sum Frequency Generation (2D-EVSFG) for Vibronic and Solvent Couplings of Molecules at Interfaces and Surfaces.

Many photoinduced excited states' relaxation processes and chemical reactions occur at interfaces and surfaces, including charge transfer, energy transfer, proton transfer, proton-coupled electron transfer, configurational dynamics, conical intersections, etc. Of them, interactions of electronic and vibrational motions, namely, vibronic couplings, are the main determining factors for the relaxation processes or reaction pathways. However, time-resolved electronic-vibrational spectroscopy for interfaces and surfaces is lacking. Here we develop interface/surface-specific two-dimensional electronic-vibrational sum frequency generation spectroscopy (2D-EVSFG) for time-dependent vibronic coupling of excited states at interfaces and surfaces. We further demonstrate the fourth-order technique by investigating vibronic coupling, solvent correlation, and time evolution of the coupling for photoexcited interface-active molecules, crystal violet (CV), at the air/water interface as an example. The two vibronic absorption peaks for CV molecules at the interface from the 2D-EVSFG experiments were found to be more prominent than their counterparts in bulk from 2D-EV. Quantitative analysis of the vibronic peaks in 2D-EVSFG suggested that a non-Condon process participates in the photoexcitation of CV at the interface. We further reveal vibrational solvent coupling for the zeroth level on the electronic state with respect to that on the ground state, which is directly related to the magnitude of its change in solvent reorganization energy. The change in the solvent reorganization energy at the interface is much smaller than that in bulk methanol. Time-dependent center line slopes (CLSs) of 2D-EVSFG also showed that kinetic behaviors of CV at the air/water interface are significantly different from those in bulk methanol. Our ultrafast 2D-EVSFG experiments not only offer vibrational information on both excited states and the ground state as compared with the traditional doubly resonant sum frequency generation and electronic-vibrational coupling but also provide vibronic coupling, dynamical solvent effects, and time evolution of vibronic coupling at interfaces.

Interface Catalysts of Ni3Fe1 Layered Double Hydroxide and Titanium Carbide for High-Performance Water Oxidation in Alkaline and Natural Conditions.

The electrocatalytic oxygen evolution reaction (OER) is important for many renewable energy technologies. Developing cost-effective electrocatalysts with high performance remains a great challenge. Here, we successfully demonstrate our novel interface catalyst comprised of Ni3Fe1-based layered double hydroxides (Ni3Fe1-LDH) vertically immobilized on a two-dimensional MXene (Ti3C2Tx) surface. The Ni3Fe1-LDH/Ti3C2Tx yielded an anodic OER current of 100 mA cm-2 at 0.28 V versus reversible hydrogen electrode (RHE), nearly 74 times lower than that of the pristine Ni3Fe1-LDH. Furthermore, the Ni3Fe1-LDH/Ti3C2Tx catalyst requires an overpotential of only 0.31 V versus RHE to deliver an industrial-level current density as high as 1000 mA cm-2. Such excellent OER activity was attributed to the synergistic interface effect between Ni3Fe1-LDH and Ti3C2Tx. Density functional theory (DFT) results further reveal that the Ti3C2Tx support can efficiently accelerate the electron extraction from Ni3Fe1-LDH and tailor the electronic structure of catalytic sites, resulting in enhanced OER performance.

Orientational Coupling of Molecules at Interfaces Revealed by Two-Dimensional Electronic-Vibrational Sum Frequency Generation (2D-EVSFG).

Photoinduced relaxation processes at interfaces are intimately related to many fields such as solar energy conversion, photocatalysis, and photosynthesis. Vibronic coupling plays a key role in the fundamental steps of the interface-related photoinduced relaxation processes. Vibronic coupling at interfaces is expected to be different from that in bulk due to the unique environment. However, vibronic coupling at interfaces has not been well understood due to the lack of experimental tools. We have recently developed a two-dimensional electronic-vibrational sum frequency generation (2D-EVSFG) for vibronic coupling at interfaces. In this work, we present orientational correlations in vibronic couplings of electronic and vibrational transition dipoles as well as the structural evolution of photoinduced excited states of molecules at interfaces with the 2D-EVSFG technique. We used malachite green molecules at the air/water interface as an example, to be compared with those in bulk revealed by 2D-EV. Together with polarized VSFG and ESHG experiments, polarized 2D-EVSFG spectra were used to extract relative orientations of an electronic transition dipole and vibrational transition dipoles at the interface. Combined with molecular dynamics calculations, time-dependent 2D-EVSFG data have demonstrated that structural evolutions of photoinduced excited states at the interface have different behaviors than those in bulk. Our results showed that photoexcitation leads to intramolecular charge transfer but no conical interactions in 25 ps. Restricted environment and orientational orderings of molecules at the interface are responsible for the unique features of vibronic coupling.

Incidence, Diagnosis, and Management of Neuromas Following Radiofrequency Ablation Treatment: a Narrative Review.

OBJECTIVE: To determine the epidemiology of neuroma formation as a complication following radiofrequency ablation for chronic pain conditions as well as reviewing the diagnosis and management of neuromas. DESIGN: Evidence-based narrative review and critical appraisal of literature. RESULTS: A comprehensive review of the literature generated one case report describing neuroma formation following lumbar facet medial branch radiofrequency denervation. The rare incidence may be explained by neuroma pathophysiology and peripheral nerve injury produced by radiofrequency ablation, in combination with its asymptomatic nature. Diagnosis of neuromas is predominantly confirmed by clinical history and physical exam with potential for nerve blocks or imaging. Ultrasound has been suggested as a primary imaging modality with magnetic resonance imaging as a secondary option. Neuroma management ranges from conservative therapy to surgery with varying success rates. CONCLUSIONS: Neuroma formation following radiofrequency ablation procedures is exceedingly rare and could be a hypothetical concern in clinical practice. However, the true incidence may be inaccurate given the asymptomatic nature of neuromas.

Activity of muscle sympathetic neurons during normotensive pregnancy.

In pathological populations, elevated sympathetic activity is associated with increased activity of individual sympathetic neurons. We used custom action potential detection software to analyze multiunit sympathetic activity in 18 normotensive pregnant women (third trimester; 33 ± 5 wk) and 19 nonpregnant women at rest and a subset (10 and 13, respectively) during a cold pressor challenge. Although the number of action potentials per burst and number of active amplitude-based "clusters" were not different between groups, the total number of sympathetic action potentials per minute was higher in pregnant women at rest. Individual clusters were active predominately once per burst, suggesting they represent single neurons. Action potentials occurred in closer succession in normotensive pregnant (interspike interval 36 ± 10 ms) versus nonpregnant women (50 ± 27 ms; P < 0.001) at rest. Pregnant women had a lower total peripheral resistance (11.7 ± 3.0 mmHg·l-1·min) than nonpregnant women (15.1 ± 2.7 mmHg·l-1·min; P < 0.001), indicating a blunted neurovascular transduction. The cold pressor reduced the number of action potentials per burst in both groups due to shortening of the R-R interval in conjunction with increased burst frequency; total neural firing per minute was unchanged. Thus elevated sympathetic activity during normotensive pregnancy is specific to increased incidence of multiunit bursts. This is likely due to decreased central gating of burst output as opposed to generalized increases in central drive. These data also reinforce the concept that pregnancy appears to be the only healthy state of chronic sympathetic hyperactivity of which we are aware.

Reduced uterine perfusion pressure decreases functional capillary density in skeletal muscle.

The purpose of this study was to examine the functional and structural capillary density in the reduced uterine perfusion pressure (RUPP) model, which when performed during pregnancy is an established animal model of preeclampsia. We hypothesized that the RUPP model would be associated with capillary rarefaction and impaired capillary perfusion, which would be more pronounced in the pregnant state. Female Sprague-Dawley rats (n = 32) were randomized to nonpregnancy (Nonpregnant) or breeding (Pregnant) at 12 wk of age and again to RUPP or SHAM surgeries on gestational day (GD) 14 (or equivalent age in nonpregnant rats). On GD 20 (or equivalent), capillary structure and perfusion of the extensor digitorum longus were imaged using digital intravital video microscopy. Functional videos were analyzed by a blinded observer to measure capillary density, expressed as capillaries per millimeter intersecting three staggered reference lines (200 µm). Flow was scored as the percentage of capillaries having 1) continuous, 2) intermittent, or 3) stopped flow. Total capillary density was not different between groups. There was a main effect of RUPP surgery resulting in decreased continuous flow vessels (P < 0.01) and increased stopped flow (P < 0.01), which was driven by differences between pregnant animals (Continuous flow: pregnant SHAM 80.1 ± 7.8% vs. pregnant RUPP 67.8 ± 11.2%, P < 0.05) (Stopped flow: pregnant SHAM 8.7 ± 3.2% vs. pregnant RUPP 17.9 ± 5.7%, P < 0.01). Our results demonstrate that the RUPP surgery is associated with a decrease in functional capillary density in skeletal muscle that is more pronounced in the pregnant state, which may contribute to the vascular pathophysiology observed in preeclampsia.

Infecçöes agudas do sistema nervoso central (SNC) e doença meningocócica em Goiás.(1971-1994) / Central nervous system acute infections and meningococcal disease in Goiás-Brazil(1971-1994)

Realata-se a ocorrência de 9.888 casos internados em Goiânia, sendo 4.027(40,73(pôr cento)) da Capital e 5.861(59,27(pôr cento)) procedentes do interior. Este número de internaçÆes corresponde a 56,96(pôr cento) das notificaçÆes do Estado de Goiás, no período de estudo, (17,539). As infecçÆes de origem bacteriana foram de 4.149 (41,96(pôr cento)), as de doença meningocócica de 3.103 (31,38(pôr cento)) e as assépticas de 2.636 (26,66(pôr cento)). Dentre as bacterianas, em apenas 980 (23,62(pôr cento)) isolou-se o agente etiológico: Haemophylus influenzae 411 (9,91(pôr cento));Strptococcus pneumoniae 359 (8,65(pôr cento)); Staphylococcus sp. 151 (3,64(pôr cento)) e Streptococcus sp. 59 (1,42 (pôr cento)). A utilizaçäo de antibióticos antes da internaçäo foi pesquisada no LCR de 278 pacientes e detectado em 33 (11,8(pôr cento)). Dentre as assépticas, 80 (3,03(pôr cento)) foram classificadas como tuberculosas pelos dados clínicos, radiológicos e epidemiológicos. As tentativas de identificar o Mycobacterium tuberculosis no líquor pela bacterioscopia e pela cultura foram praticamente nulas. Em 37(1,40(pôr cento)) dos líquores claros identificou-se e isolou-se o Cryptococcus neoformans. Os casos de criptococose aqui relatados näo estavam relacionados com a SIDA. A Neisseria meningitidis foi identificada laboratorialmente em 2.950 (95,07(pôr cento)) dos casos, pela bacterioscopia, cultura e/ou contraimunoeletroforese; em 153 (4,93(pôr cento)) pacientes a classificaçäo de doença meningocócica foi feita pela presença de lesÆes hemorrágicas cutâneas associadas ao quadro clínico sugestivo, com ou sem choque vascular. O número de internaçÆes de menores de 5 anos foi de 4.438 (44,88 (pôr cento)) e foram a óbito 970 pacientes com índice de letalidade de 21,61(pôr cento) menor do que em 170 pacientes maiores de 50 anos (28,82(pôr cento))

Caxumba e infecçåo aguda do sistema nervoso central (SNC) / Mumps and infections of Central Nervous System (C.N.S.)

Dentre 916 casos de "Meningite Asséptica" internados no Hospital de Doenças Tropicais de Goiânia no período de 1982-1993, o vírus da caxumba foi o mais provável agente etiológico dde 157 (17,14 pôr cento) casos, pois havia concomitância de parotidite ou história recente de contágio intradomiciliar. Foram levantados dados sobre a idade dos pacientes, o tempo de permanência hospitalar, o tempo de duraçåo da doença e em que dia da caxumba surgiram os primeiros sinais do acometimento do S.N.C.. Os exames de rotina do L.C.R. foram solicitaddos e, no sangue a amilasemia. O tipo de acometimento nervoso, a concomitância de pancreatite e os anos e meses de maiores e menores incidências såo citados. O autor eenfatiza que o acometimento cerebral nåo deve ser considerado uma complicaçåo e sim forma clínica da parotidite epidêmica do mesmo modo que a pancreatite e a orquite

Tétano umbilical. Relato de complicaçäo incomum: prolapso uterino / Umbilical Tetanus. Report of an incommon complication: uterine prolapse

Discute-se sobre a raridade do caso e sua etiopatogenia; relembram os mecanismos de sustentaçäo do útero em seu sítio normal, assim como as anomalias congênitas que se acompanham do prolapso uterino. Atribuem como causa primária o fator constitucional e, como secundária a prensa abdominal atuando sobre estruturas submetidas, a longo tempo, a generosas doses de miorrelaxantes

Tétano acidental. Relato de complicaçäo incomum: fratura-luxaçäo do esterno e compressäo da artéria pulmonar / Tetanus followaring injury. Report of uncommon complications: sternal fracture-luxation and pulmonary artery compression

Relata-se caso grave de tétano generalizado, complicado por tromboflebite, septicemia, crises de apnéia, fraturas múltiplas de vértebras dorsais e fratura-luxaçäo do esterno. O paciente foi submetido aos exames radiográfico que mostraram a compressäo da artéria pulmonar, em sua origem, por fragmentos do esterno