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In vivo fluorescence imaging in the shortwave infrared (SWIR, 1,000–1,700 nm) and extended SWIR (ESWIR, 1,700–2,700 nm) regions has tremendous potential for diagnostic imaging. Although image contrast has been shown to improve as longer wavelengths are accessed, the design and synthesis of organic fluorophores that emit in these regions is challenging. Here we synthesize a series of silicon-RosIndolizine (SiRos) fluorophores that exhibit peak emission wavelengths from 1,300–1,700 nm and emission onsets of 1,800–2,200 nm. We characterize the fluorophores photophysically (both steady-state and time-resolved), electrochemically and computationally using time-dependent density functional theory. Using two of the fluorophores (SiRos1300 and SiRos1550), we formulate nanoemulsions and use them for general systemic circulatory SWIR fluorescence imaging of the cardiovascular system in mice. These studies resulted in high-resolution SWIR images with well-defined vasculature visible throughout the entire circulatory system. This SiRos scaffold establishes design principles for generating long-wavelength emitting SWIR and ESWIR fluorophores.

Rational design of bright near and shortwave infrared (NIR: 700-1000 SWIR: 1000- 2000 nm) emitters remains an open question with applications spanning imaging and photonics. Combining experiment and theory, we derive an energy gap quantum yield master equation (EQME), describing the fundamental limits in SWIR quantum yields (ϕ F ) for organic chromophores. Evaluating the photophysics of 21 polymethine NIR/SWIR chromophores to parameterize the EQME, we explain the precipitous decline of ϕ F past 900 nm through decreasing radiative rates and increasing nonradiative losses via high frequency vibrations relating to the energy gap. Using the EQME we develop an energy gap independent ϕ F NIR/SWIR chromophore comparison metric. We show electron donating character on polymethine heterocycles results in relative increases in radiative efficiency obscured by a simultaneous redshift. Finally, the EQME yields rational chromophore design insights shown by how deuteration (backed by our experimental results) or molecular aggregation increases SWIR ϕ F .

In the past few decades, research has shown interactive read alouds to have enormous benefits for developing readers and should be included as an important component of reading instruction. Yet, many teachers do not utilize interactive read alouds in their literacy instruction. This is due in part to various curricular constraints and the pressures of high stakes tests. In this case study of an urban, Title I second-grade class of Black and Latina/o students, we found that a teacher-led interactive read aloud of the book "Wonder" fostered a sense of community and empathy, increased engagement and motivation to read, and helped students develop deeper comprehension skills. The inclusion of all students in the read aloud ritual helped to develop a strong community of readers and identities in the students as competent literate beings, regardless of their reading levels.

We describe and implement an interferometric approach to decay-associated photoluminescence spectroscopy, which we term decay-associated Fourier spectroscopy (DAFS). In DAFS, the emitted photon stream from a substrate passes through a variable path length Mach-Zehnder interferometer prior to detection and timing. The interferometer encodes spectral information in the intensity measured at each detector enabling simultaneous spectral and temporal resolution. We detail several advantages of DAFS, including wavelength-range insensitivity, drift-noise cancellation, and optical mode retention. DAFS allows us to direct the photon stream into an optical fiber, enabling the implementation of superconducting nanowire single photon detectors for energy-resolved spectroscopy in the shortwave infrared spectral window (λ = 1-2 μm). We demonstrate the broad applicability of DAFS, in both the visible and shortwave infrared, using two Förster resonance energy transfer pairs: a pair operating with conventional visible wavelengths and a pair showing concurrent acquisition in the visible and the shortwave infrared regime.

Changes in the viscosity of intracellular microenvironments may indicate the onset of diseases like diabetes, blood‐based illnesses, hypertension, and Alzheimer's. To date, monitoring viscosity changes in the intracellular environment remains a challenge with prior work focusing primarily on visible light‐absorbing viscosity sensing fluorophores. Herein, a series of near‐infrared (NIR, 700–1000 nm) absorbing and emitting indolizine squaraine fluorophores (1PhSQ, 2PhSQ, SO3SQ, 1DMASQ, 7DMASQ, and 1,7DMASQ) are synthesized and studied for NIR viscosity sensitivity. 2PhSQ exhibits a very high slope in its Forster‐Hoffmann plot at 0.75 which indicates this dye is a potent viscosity sensor. The properties of the squaraine fluorophores are studied computationally via density functional theory (DFT) and time‐dependent (TD)‐DFT. Experimentally, both steady‐state and time‐resolved emission spectroscopy, absorption spectroscopy, and electrochemical characterization are conducted on the dyes. Precise photophysical tuning is observed within the series with emission maxima wavelengths as long as 881 nm for 1,7DMASQ and fluorescence quantum yields as high as 39.5 and 72.0 % for 1PhSQ in DCM and THF, respectively. The high tunability of this molecular scaffold renders indolizine squaraine fluorophores excellent prospects as viscosity‐sensitive biological imaging agents with 2PhSQ giving a dramatically higher fluorescence quantum yield (from 0.3 to 37.1 %) as viscosity increases. [ABSTRACT FROM AUTHOR]

What did it mean for portrait images to generate recognition of early modern individuals as saints? Did images make sainthood visible through a person's particularities or their conformity to perfect models? To be recognisable as an historical individual was not necessarily compatible with being recognised as a saint, either officially by Rome, or experientially by devotees. Early images of Quito's most prominent candidate for sainthood, Mariana de Jesús Paredes y Flores (1618–1645), throw into sharp relief the pressure that posthumous candidacy for sainthood brought to bear on portrait images, especially of women. Mariana's imagery reconfigures the relationship among visibility, individuality and recognition that posed a common problem for aspiring saints' portraits. Far from being transparent post-Tridentine propaganda, Mariana's early iconography works against the grain of the portrait genre, creatively addressing the tensions between individual likeness and conformity to perfect models, and between concealing sainthood and making it visible. [ABSTRACT FROM AUTHOR]

The design of bright short-wave infrared fluorophores remains a grand challenge. Here we investigate the impact of deuteration on the properties in a series of heptamethine dyes, the absorption of which spans near-infrared and SWIR regions. We demonstrate that it is a generally applicable strategy that leads to enhanced quantum yields of fluorescence, longer-lived singlet excited states and suppressed rates of non-radiative deactivation processes. [ABSTRACT FROM AUTHOR]

This guide compares emerging diagnostic software tools that aid detection and diagnosis of operational problems for large HVAC systems. We have evaluated six tools for use with energy management control system (EMCS) or other monitoring data. The diagnostic tools summarize relevant performance metrics, display plots for manual analysis, and perform automated diagnostic procedures. Our comparative analysis presents nine summary tables with supporting explanatory text and includes sample diagnostic screens for each tool.

Pivotal Response Treatment (PRT) is an empirically validated behavioral treatment for individuals with autism spectrum disorders (ASD). The purpose of the current study was to assess the efficacy of PRT for ten cognitively-able preschool-aged children with ASD in the context of a short-duration (4-month) treatment model. Most research on PRT used individual behavioral goals as outcome measures, but the current study utilized standardized assessments of broader-based social communication and adaptive skills. The children made substantial gains; however, magnitude and consistency of response across measures were variable. The results provide additional support for the efficacy of PRT as well as evidence for improvements in higher-order social communication and adaptive skill development within the context of a short-duration PRT model.