Nanoscale heterogeneity of ultrafast many-body carrier dynamics in triple cation perovskites.

In high fluence applications of lead halide perovskites for light-emitting diodes and lasers, multi-polaron interactions and associated Auger recombination limit the device performance. However, the relationship of the ultrafast and strongly lattice coupled carrier dynamics to nanoscale heterogeneities has remained elusive. Here, in ultrafast visible-pump infrared-probe nano-imaging of the photoinduced carrier dynamics in triple cation perovskite films, a ~20 % variation in sub-ns relaxation dynamics with spatial disorder on tens to hundreds of nanometer is resolved. We attribute the non-uniform relaxation dynamics to the heterogeneous evolution of polaron delocalization and increasing scattering time. The initial high-density excitation results in faster relaxation due to strong many-body interactions, followed by extended carrier lifetimes at lower densities. These results point towards the missing link between the optoelectronic heterogeneity and associated carrier dynamics to guide synthesis and device engineering for improved perovskites device performance.

Semi-empirical quantum optics for mid-infrared molecular nanophotonics.

Nanoscale infrared (IR) resonators with sub-diffraction limited mode volumes and open geometries have emerged as new platforms for implementing cavity quantum electrodynamics at room temperature. The use of IR nanoantennas and tip nanoprobes to study strong light-matter coupling of molecular vibrations with the vacuum field can be exploited for IR quantum control with nanometer spatial and femtosecond temporal resolution. In order to advance the development of molecule-based quantum nanophotonics in the mid-IR, we propose a generally applicable semi-empirical methodology based on quantum optics to describe light-matter interaction in systems driven by mid-IR femtosecond laser pulses. The theory is shown to reproduce recent experiments on the acceleration of the vibrational relaxation rate in infrared nanostructures. It also provides physical insights on the implementation of coherent phase rotations of the near-field using broadband nanotips. We then apply the quantum framework to develop general tip-design rules for the experimental manipulation of vibrational strong coupling and Fano interference effects in open infrared resonators. We finally propose the possibility of transferring the natural anharmonicity of molecular vibrational levels to the resonator near-field in the weak coupling regime to implement intensity-dependent phase shifts of the coupled system response with strong pulses and develop a vibrational chirping model to understand the effect. The semi-empirical quantum theory is equivalent to first-principles techniques based on Maxwell's equations, but its lower computational cost suggests its use as a rapid design tool for the development of strongly coupled infrared nanophotonic hardware for applications ranging from quantum control of materials to quantum information processing.

Ultrafast infrared nano-imaging of far-from-equilibrium carrier and vibrational dynamics.

Ultrafast infrared nano-imaging has demonstrated access to ultrafast carrier dynamics on the nanoscale in semiconductor, correlated-electron, or polaritonic materials. However, mostly limited to short-lived transient states, the contrast obtained has remained insufficient to probe important long-lived excitations, which arise from many-body interactions induced by strong perturbation among carriers, lattice phonons, or molecular vibrations. Here, we demonstrate ultrafast infrared nano-imaging based on excitation modulation and sideband detection to characterize electron and vibration dynamics with nano- to micro-second lifetimes. As an exemplary application to quantum materials, in phase-resolved ultrafast nano-imaging of the photoinduced insulator-to-metal transition in vanadium dioxide, a distinct transient nano-domain behavior is quantified. In another application to lead halide perovskites, transient vibrational nano-FTIR spatially resolves the excited-state polaron-cation coupling underlying the photovoltaic response. These examples show how heterodyne pump-probe nano-spectroscopy with low-repetition excitation extends ultrafast infrared nano-imaging to probe elementary processes in quantum and molecular materials in space and time.

2D Vibrational Exciton Nanoimaging of Domain Formation in Self-Assembled Monolayers.

Order, disorder, and domains affect many of the functional properties in self-assembled monolayers (SAMs). However, carrier transport, wettability, and chemical reactivity are often associated with collective effects, where conventional imaging techniques have limited sensitivity to the underlying intermolecular coupling. Here we demonstrate vibrational excitons as a molecular ruler of intermolecular wave function delocalization and nanodomain size in SAMs. In the model system of a 4-nitrothiophenol (4-NTP) SAM on gold, we resolve coupling-induced peak shifts of the nitro symmetric stretch mode with full spatio-spectral infrared scattering scanning near-field optical microscopy. From modeling of the underlying 2D Hamiltonian, we infer domain sizes and their distribution ranging from 3 to 12 nm across a field of view on the micrometer scale. This approach of vibrational exciton nanoimaging is generally applicable to study structural phases and domains in SAMs and other molecular interfaces.

The "Speckle Sign" in the Diagnosis of Posterior Compartment Endometriosis.

OBJECTIVE: To determine usefulness of the "speckle sign" in the diagnosis of deep invasive endometriosis. MATERIALS AND METHODS: This HIPAA-compliant, institutional review board-approved retrospective study with informed consent waived included 25 women (mean age 20-69 years) with histopathologically confirmed posterior cul-de-sac endometriosis between 2013 and 2018. Transvaginal ultrasound exams of these patients were reviewed by 2 expert radiologists searching for the "speckle sign," defined as irregular obliteration of the posterior cul-de-sac and bright (hyperechoic) internal echoes. The frequency of additional findings such as "kissing ovaries," endometriomas in the adnexa, bowel tethering in the posterior pelvic compartment, retroflexed uterus, adenomyosis, and pelvic free fluid were also analyzed. Data regarding clinical features, histopathologic findings and management were collected through a review of the medical record. RESULTS: Reader one identified posterior compartment endometriosis in 20/25 patients, and reader two in 22/25 patients, with 96% agreement. Adnexal endometriomas were found in 21/25 patients for both readers (k = 0.70) and were bilateral in 23% of patients. The ovaries were adherent to each other in the midline ("kissing ovaries") in 50% of patients; the bowel was tethered anteriorly in 20%; the presence of adenomyosis was seen in about 27%, and a retroflexed uterus was seen in 24% of patients. CONCLUSIONS: The speckle sign could be helpful in making the diagnosis of posterior compartment endometriosis, and the sign is often found in conjunction with other imaging features of endometriosis.

Sonovaginography: A Useful Technique in the Assessment of the Lower Genital Tract.

Conventional sonographic evaluation of the cervix and vagina is compromised by inattention, poor subject contrast, and obscuring artifacts. We describe a technique involving distention of the vaginal canal and fornices with ultrasound gel, providing an acoustic window for improved definition of the cervix and vagina. This exam is usually performed in concert with transvaginal sonography, but a transabdominal or transperineal approach may be more useful in selected scenarios. A wide variety of formerly sonographically inconspicuous conditions are demonstrable with this technique, many of which were undetected or inadequately characterized on the physical exam. Cervical polyps were the most commonly seen abnormality.

Targeted Nanoparticle Thermometry: A Method to Measure Local Temperature at the Nanoscale Point Where Water Vapor Nucleation Occurs.

An optical nanothermometer technique based on laser trapping, moving and targeted attaching an erbium oxide nanoparticle cluster is developed to measure the local temperature. The authors apply this new nanoscale temperature measuring technique (limited by the size of the nanoparticles) to measure the temperature of vapor nucleation in water. Vapor nucleation is observed after superheating water above the boiling point for degassed and nondegassed water. The average nucleation temperature for water without gas is 560 K but this temperature is lowered by 100 K when gas is introduced into the water. The authors are able to measure the temperature inside the bubble during bubble formation and find that the temperature inside the bubble spikes to over 1000 K because the heat source (optically-heated nanorods) is no longer connected to liquid water and heat dissipation is greatly reduced.

Merkel cell carcinoma in a patient with noninvasive vulvar Paget's disease.

We present the first case of inguinal Merkel cell carcinoma of unknown primary origin in a patient with vulvar Paget's disease. Correlation with immune suppression of both entities warrants further investigation. Additionally, this case highlights the value of ultrasound scanning in the detection of inguinal metastasis.

Complete septate uterus, obstructed hemivagina, and ipsilateral renal anomaly: pregnancy course complicated by a rare urogenital anomaly.

BACKGROUND: Abnormalities of the female reproductive tract are associated with a multitude of intrapartum complications. In the case that follows, we report the complicated pregnancy course of a woman diagnosed postpartum with the uncommon syndrome of obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) associated with a complete septate uterus. CASE: A 19-year-old nulliparous woman with a history of a right nephrectomy secondary to multicystic dysplastic kidney disease presented with premature rupture of membranes at 30 weeks' gestation. After failed induction of labor at 34 weeks' gestation, a uterine anomaly was discovered at the time of cesarean section. Magnetic resonance imaging performed postpartum revealed a complete septate uterus, longitudinal vaginal septum, and obstructed right hemivagina. CONCLUSION: The OHVIRA syndrome is classically associated with uterus didelphys, not complete septate uterus as in this woman. This case illustrates the potential for intrapartum complications in women with abnormalities of the urogenital tract.

First-trimester Doppler investigation of the uterine circulation.

There is now strong evidence that fetal events can significantly impact postnatal health and disease development. Doppler velocimetry can identify some early pathologic changes in pregnancy. Many investigators have tried to delineate the normal and pathologic models of the uterine circulation in the first trimester, but much has yet to be defined. A discrete amount of confusion derives from the incomplete knowledge of the initial placental development, and particularly the development of the intervillous circulation. This article comprehensively reviews the literature on first-trimester Doppler in both normal and complicated pregnancies, and briefly discusses potential future areas of application.

The role of sonographic endometrial patterns and endometrial thickness in the differential diagnosis of ectopic pregnancy.

OBJECTIVE: The purpose of this study was to examine the usefulness of the endometrial trilaminar pattern and thickness in the diagnosis of ectopic pregnancy. STUDY DESIGN: We reviewed patient records for clinical and ultrasonographic data for patients with the suspicion of ectopic pregnancy. The trilaminar pattern and endometrial thickness were tested as predictors for the diagnosis of ectopic pregnancy. RESULTS: The trilaminar pattern had a specificity of 94% and sensitivity of 38% (n = 403 women). The mean endometrial thickness was thinner in patients with ectopic, compared with normal pregnancy (9.5 +/- 5.7 mm vs 12.4 +/- 5.9 mm; P = .035). Patients with normal pregnancy or first-trimester losses had comparable thicknesses (12.4 +/- 5.9 mm vs 12.5 +/- 8.0 mm). The receiver operator curve showed that there was no thickness value useful for the diagnosis of ectopic pregnancy. CONCLUSION: The trilaminar pattern is specific for the diagnosis of ectopic pregnancy, but it is associated with low sensitivity. The endometrial thickness tends to be thinner in patients with an ectopic pregnancy.

Recognition of the ovaries and ovarian origin of pelvic masses with CT.

Knowledge of the morphologic features and ligamentous attachments of the ovaries, the relationship of the ovary to the ureter, and the course of the ovarian vein and artery is necessary for confident recognition of the ovaries and differentiation between ovarian and nonovarian masses with computed tomography (CT). The suspensory ligament attaches the ovary to the pelvic sidewall and transmits the ovarian vein and artery. This ligament may be seen at CT as a linear or fan-shaped soft-tissue band leading to the ovary. The utero-ovarian ligament is occasionally visualized with CT as a soft-tissue band between the uterus and ovary. The ovaries are usually located anterior or anteromedial to the pelvic ureters, whereas iliac lymph nodes are lateral or posterolateral to the ureters. Therefore, an ovarian mass displaces the ureter posteriorly or posterolaterally, whereas a large lymph node mass displaces the ureter medially or anteromedially. An ovarian mass may be draped by ovarian parenchyma, thus revealing the origin of the mass. Tracking the ovarian vein from near the level of the renal vessels caudally to the pelvis leads to the suspensory ligament region and is often helpful in identifying the ovary and differentiating ovarian and nonovarian masses.