Integrated immune monitoring of HCMV infection in pregnant women with complications and its association with adverse pregnancy outcomes.

Human Cytomegalovirus (HCMV) infection is associated with bad obstetric history (BOH) and adverse pregnancy outcomes (APO). Here, we characterized antiviral humoral profiles, systemic and virus specific cellular immune responses concurrently in pregnant women (n = 67) with complications including BOH and associated these signatures with pregnancy outcomes. Infection status was determined using nested blood PCR, seropositivity and IgG avidity by ELISA. Systemic and HCMV specific (pp65) cellular immune responses were evaluated by flow cytometry. Seropositivity was determined for other TORCH pathogens (n = 33) on samples with recorded pregnancy outcomes. This approach was more sensitive in detecting HCMV infection. Blood PCR positive participants, irrespective of their IgG avidity status, had higher cytotoxic potential in circulating CD8+ T cells (p < 0.05) suggesting that infection associated cellular dysfunction was uncoupled with avidity maturation of antiviral humoral responses. Also, impaired anamnestic degranulation of HCMV-pp65-specific T cells compared to HCMV blood PCR negative participants (p < 0.05) was observed. APO correlated with HCMV blood PCR positivity but not serostatus (p = 0.0039). Most HCMV IgM positive participants (5/6) were HCMV blood PCR positive with APO. None were found to be IgM positive for other TORCH pathogens. Multiple TORCH seropositivity however was significantly enriched in the APO group (p = 0.024). Generation of HCMV specific high avidity IgG antibodies had no bearing on APO (p = 0.9999). Our study highlights the utility of an integrated screening approach for antenatal HCMV infection in the context of BOH, where infection is associated with systemic and virus specific cellular immune dysfunction as well as APO.

Modeling broadband cloaking using 3D nano-assembled plasmonic meta-structures.

The concept of "cloaking" an object is a very attractive one, especially in the visible (VIS) and near infra-red (NIR) regions of the electromagnetic spectrum, as that would reduce the visibility of an object to the eye. One possible route to achieving this goal is by leveraging the plasmonic property of metallic nanoparticles (NPs). We model and simulate light in the VIS and NIR scattered by a core of a homogeneous medium, covered by plasmonic cloak that is a spherical shell composed of gold nanoparticles (AuNPs). To consider realistic, scalable, and robust plasmonic cloaks that are comparable, or larger, in size to the wavelength, we introduce a multiscale simulation platform. This model uses the multiple scattering theory of Foldy and Lax to model interactions of light with AuNPs combined with the method of fundamental solutions to model interactions with the core. Numerical results of our simulations for the scattering cross-sections of core-shell composite indicate significant scattering suppression of up to 50% over a substantial portion of the desired spectral range (400 - 600 nm) for cores as large as 900 nm in diameter by a suitable combination of AuNP sizes and filling fractions of AuNPs in the shell.

Size and temperature dependence of photoluminescence of hybrid perovskite nanocrystals.

In this work, we studied the effects of particles' size and temperature on the photoluminescence (PL) of CH3NH3PbBr3 perovskite nanocrystals (PNCs), with the PNC size controlled by varying the surface passivating ligands. The structural and optical properties of the PNCs were investigated using UV-Vis and PL spectroscopy, revealing strong quantum confinement effects. Temperature dependent PL measurements showed the spectral blue shift of the PL peak for the small PNCs (3.1 ± 0.2 nm) with decreasing temperature from 300 K to 20 K, which is opposite to the red shift with decreasing temperature observed for large- (9.2 ± 0.5 nm) and middle-sized (5.1 ± 0.3 nm) PNCs. The PL lifetime also increased with increasing temperature for the larger PNCs, while it remained about the same for the small and middle-sized PNCs. This increase in lifetime with temperature is attributed to exciton dissociation to free carriers at higher temperatures and to the formation of polar domains in the PNCs. However, the small and middle-sized PNCs did not show such a trend, which may be due to efficient defect passivation as higher concentration of 3-aminopropyl trimethoxysilane (APTMS) was used and to the role of particle size in surface state delocalization. Cryo-X-ray diffraction showed no new peak formation or peak splitting as temperature was varied, which suggests efficient crystal phase stabilization in PNCs of all three sizes controlled by the concentration of APTMS. These results emphasize the importance of size and surface properties of PNCs in their optical properties such as PL quantum yield, PL lifetime, and crystal phase stability.

Low temperature excitonic spectroscopy and dynamics as a probe of quality in hybrid perovskite thin films.

We have developed a framework for using temperature dependent static and dynamic photoluminescence (PL) of hybrid organic-inorganic perovskites (PVSKs) to characterize lattice defects in thin films, based on the presence of nanodomains at low temperature. Our high-stability PVSK films are fabricated using a novel continuous liquid interface propagation technique, and in the tetragonal phase (T > 120 K), they exhibit bi-exponential recombination from free charge carriers with an average PL lifetime of ∼200 ns. Below 120 K, the emergence of the orthorhombic phase is accompanied by a reduction in lifetimes by an order of magnitude, which we establish to be the result of a crossover from free carrier to exciton-dominated radiative recombination. Analysis of the PL as a function of excitation power at different temperatures provides direct evidence that the exciton binding energy is different in the two phases, and using these results, we present a theoretical approach to estimate this variable binding energy. Our findings explain this anomalous low temperature behavior for the first time, attributing it to an inherent fundamental property of the hybrid PVSKs that can be used as an effective probe of thin film quality.

All-optical switching of nematic liquid crystal films driven by localized surface plasmons.

We have demonstrated an all-optical technique for reversible in-plane and out-of-plane switching of nematic liquid crystal molecules in few micron thick films. Our method leverages the highly localized electric fields ("hot spots") and plasmonic heating that are generated in the near-field region of densely packed gold nanoparticle layers optically excited on-resonance with the localized surface plasmon absorption. Using polarized microscopy and transmission measurements, we observe this switching from homeotropic to planar over a temperature range starting at room temperature to just below the isotropic transition, and at on-resonance excitation intensity less than 0.03 W/cm(2). In addition, we controllably vary the in-plane directionality of the liquid crystal molecules in the planar state by altering the linear polarization of the incident excitation. Using discrete dipole simulations and control measurements, we establish spectral selectivity in this new and interesting perspective for photonic application using low light power.

Magnetic field induced quantum dot brightening in liquid crystal synergized magnetic and semiconducting nanoparticle composite assemblies.

The design and development of multifunctional composite materials from artificial nano-constituents is one of the most compelling current research areas. This drive to improve over nature and produce 'meta-materials' has met with some success, but results have proven limited with regards to both the demonstration of synergistic functionalities and in the ability to manipulate the material properties post-fabrication and in situ. Here, magnetic nanoparticles (MNPs) and semiconducting quantum dots (QDs) are co-assembled in a nematic liquid crystalline (LC) matrix, forming composite structures in which the emission intensity of the quantum dots is systematically and reversibly controlled with a small applied magnetic field (<100 mT). This magnetic field-driven brightening, ranging between a two- to three-fold peak intensity increase, is a truly cooperative effect: the LC phase transition creates the co-assemblies, the clustering of the MNPs produces LC re-orientation at atypical low external field, and this re-arrangement produces compaction of the clusters, resulting in the detection of increased QD emission. These results demonstrate a synergistic, reversible, and an all-optical process to detect magnetic fields and additionally, as the clusters are self-assembled in a fluid medium, they offer the possibility for these sensors to be used in broad ranging fluid-based applications.

Self-assembled nanoparticle micro-shells templated by liquid crystal sorting.

A current goal in nanotechnology focuses on the assembly of different nanoparticle types into 3D organized structures. In this paper we report the use of a liquid crystal host phase in a new process for the generation of micron-scale vesicle-like nanoparticle shells stabilized by ligand-ligand interactions. The constructs formed consist of a robust, thin spherical layer, composed of closely packed quantum dots (QDs) and stabilized by local crystallization of the mesogenic ligands. Ligand structure can be tuned to vary QD packing within the shell and made UV cross-linkable to allow for intact shell extraction into toluene. The assembly method we describe could be extended to other nanoparticle types (metallic, magnetic etc.), where hollow shell formation is controlled by thermally sorting mesogen-functionalized nanoparticles in a liquid crystalline host material at the isotropic to nematic transition. This process represents a versatile method for making non-planar 3D nano-assemblies.

Tuning quantum-dot organization in liquid crystals for robust photonic applications.

Mesogenic ligands have the potential to provide control over the dispersion and stabilization of nanoparticles in liquid crystal (LC) phases. The creation of such hybrid materials is an important goal for the creation of soft tunable photonic devices, such as the LC laser. Herein, we present a comparison of isotropic and mesogenic ligands attached to the surface of CdSe (core-only) and CdSe/ZnS (core/shell) quantum dots (QDs). The mesogenic ligand's flexible arm structure enhances ligand alignment, with the local LC director promoting QD dispersion in the isotropic and nematic phases. To characterize QD dispersion on different length scales, we apply fluorescence microscopy, X-ray scattering, and scanning confocal photoluminescent imaging. These combined techniques demonstrate that the LC-modified QDs do not aggregate into the dense clusters observed for dots with simple isotropic ligands when dispersed in liquid crystal, but loosely associate in a fluid-like droplet with an average interparticle spacing >10 nm. Embedding the QDs in a cholesteric cavity, we observe comparable coupling effects to those reported for more closely packed isotropic ligands.

The prevalence and impact of mortality of the acute respiratory distress syndrome on admissions of patients with ischemic stroke in the United States.

PURPOSE: To determine the epidemiology of the acute respiratory distress syndrome (ARDS) and impact on in-hospital mortality in admissions of patients with acute ischemic stroke (AIS) in the United States. METHODS: Retrospective cohort study of admissions with a diagnosis of AIS and ARDS from 1994 to 2008 identified through the Nationwide Inpatient Sample. RESULTS: During the 15-year study period, we found 55 58 091 admissions of patients with AIS. The prevalence of ARDS in admissions of patients with AIS increased from 3% in 1994 to 4% in 2008 (P < .001). The ARDS was more common among younger men, nonwhites, and associated with history of congestive heart failure, hypertension, chronic obstructive pulmonary disease, renal failure, chronic liver disease, systemic tissue plasminogen activator, craniotomy, angioplasty or stent, sepsis, and multiorgan failures. Mortality due to AIS and ARDS decreased from 8% in 1994 to 6% in 2008 (P < .001) and 55% in 1994 to 45% in 2008 (P < .001), respectively. The ARDS in AIS increased in-hospital mortality (odds ratio, 14; 95% confidence interval, 13.5-14.3). A significantly higher length of stay was seen in admissions of patients with AIS having ARDS. CONCLUSION: Our analysis demonstrates that ARDS is rare after AIS. Despite an overall significant reduction in mortality after AIS, ARDS carries a higher risk of death in this patient population.

Association of morphologic and demographic features of intracranial aneurysms with their rupture: a retrospective analysis.

BACKGROUND: In spite of its common occurrence, the factors predictive of the rupture of intracranial aneurysms (IAs) remain poorly defined. METHOD: A retrospective analysis of patients admitted with a primary diagnosis of cerebral aneurysm in a single institution was done. The factors studied were age, sex, size, site, side, multiplicity, neck type, aspect ratio, positive family history, smoking and drinking habits, and hypertension. The morphological parameters were evaluated for a total of 5,138 aneurysms obtained from the 2,347 patients. Factors found significant on univariate analysis were further tested on a multivariate model. FINDINGS: We found 1,088 patients (46.36%) had at least a single aneurysmal rupture. Among the morphologic factors, size greater than 10 mm, right sidedness, aspect ratio greater than 1.6, deviated neck type, and multiplicity were found to be associated with higher incidences of rupture. Aneurysms on posterior communicating and middle cerebral arteries were found to be more prone to rupture. The demographic factors that were more linked with the ruptured aneurysms were positive family history, smoking, and hypertension. CONCLUSIONS: Relevant cases should be started on intensive lifestyle modification, and extensive screening of those with a positive family history is highly warranted. All "at-risk" patients should be evaluated for early surgical intervention.

Impact of Hunt-Hess grade on the glycemic status of aneurysmal subarachnoid hemorrhage patients.

OBJECTIVE: This study has explored the impact of Hunt-Hess (H-H) grade of aneurysmal subarachnoid hemorrhage (aSAH) on the glycemic status of such patients during their intensive care unit (ICU) stay and has also analyzed whether H-H grade predicts their outcome independent of their glycemic status. MATERIALS AND METHODS: This was a retrospective case record review of prospectively maintained database of 1090 previously non-diabetic aSAH patients admitted to Thomas Jefferson University Hospital, Philadelphia. H-H grade of SAH, serum and CSF glucose on admission, serum glucose on the day of surgery and 14 days post-surgery, as well as the extended Glasgow Outcome Score (GOS-E score) at discharge were noted. After univariate analysis, significant variables (P < 0.05) were entered into a logistic regression model to identify significant associations with admission H-H grade. RESULTS: Although admission serum glucose was significantly higher for H-H grades 4-5 than grades 1-3 (P < 0.001); after postoperative day 4, the difference between the H-H grades got blurred. Admission CSF glucose was also significantly higher for H-H grades 3-4 than for grades 1-3 and 5 (P < 0.001). H-H grades 4-5 were related with higher incidences of both hypoglycemia (serum glucose level < 80 mg/dl) and hyperglycemia (serum glucose level > 200 mg/dl) (P < 0.001) during the 14-day period of ICU stay. Also, the relationship between serum and CSF glucose levels at admission increased with HH grades 1 through 4, but became negative and more tightly bound at H-H grade 5. Admission H-H grades 4-5 contributed to poor outcome compared to lower H-H grades (P < 0.0001). CONCLUSION: Poor admission H-H grades lead to poor immediate glycemic status as well as poor short-term outcome, and it is dependent on serum glucose but independent of CSF glucose in predicting the outcome.

Mechanistic insight into deep holes from interband transitions in Palladium nanoparticle photocatalysts.

Utilizing hot electrons generated from localized surface plasmon resonance is of widespread interest in the photocatalysis of metallic nanoparticles. However, hot holes, especially generated from interband transitions, have not been fully explored for photocatalysis yet. In this study, a photocatalyzed Suzuki-Miyaura reaction using mesoporous Pd nanoparticle photocatalyst served as a model to study the role of hot holes. Quantum yields of the photocatalysts increase under shorter wavelength excitations and correlate to "deeper" energy of the holes from the Fermi level. This work suggests that deeper holes in the d-band catalyze the oxidative addition of aryl halide R-X onto Pd0 at the nanoparticles' surface to form R-PdII-X complex, thus accelerating the rate-determining step of the catalytic cycle. The hot electrons do not play a decisive role. In the future, catalytic mechanisms induced by deep holes should deserve as much attention as the well-known hot electron transfer mechanism.

Tuning three-dimensional nano-assembly in the mesoscale via bis(imino)pyridine molecular functionalization.

We investigate the effect of bis(imino)pyridine (BIP) ligands in guiding self-assembly of semiconducting CdSe/ZnS quantum dots (QDs) into three-dimensional multi-layered shells with diameters spanning the entire mesoscopic range, from 200 nm to 2 µm. The assembly process is directed by guest-host interactions between the BIP ligands and a thermotropic liquid crystal (LC), with the latter's phase transition driving the process. Characterization of the shell structures, through scanning electron microscopy and dynamic light scattering, demonstrates that the average shell diameter depends on the BIP structure, and that changing one functional group in the chemical scaffold allows systematic tuning of shell sizes across the entire range. Differential scanning calorimetry confirms a relationship between shell sizes and the thermodynamic perturbation of the BIP molecules to the LC phase transition temperature, allowing analytical modeling of shell assembly energetics. This novel mechanism to controllably tune shell sizes over the entire mesoscale via one standard protocol is a significant development for research on in situ cargo/drug delivery platforms using nano-assembled structures.

Synthesis and Properties of Stable Amino Metal Halide Molecular Clusters in the Solid State.

Nanosized molecular clusters (MCs) composed of PbBr2 and neutral ligand butylamine (BTYA) with unique optical properties in solution and solid states have been synthesized using ligand-assisted reprecipitation and spin-coating, separately. The studies of their optical properties using ultraviolet-visible (UV-vis) absorption and photoluminescence (PL) show the first electronic absorption and PL band of the MCs at 401 and 411 nm, respectively, for the solution and solid state samples that exhibit good stability under ambient conditions. Low-temperature PL spectra below 30 K show vibronic peaks indicative of a single size or a very narrow size distribution of the MCs. On the basis of Raman, X-ray diffraction, and transmission electron microscopy measurements, a layered structural model is proposed for the MCs with a BTYA ligand capping on the surface of the corner-shared tilted [PbBr6]4- octahedral framework. The stable and retained structure of MCs in the solid state is promising for photonics applications.

Incidence of postoperative pain after single-visit and multiple-visit root canal therapy: A randomized controlled trial.

Background: Short-term complications after root canal therapy (RCT) include mild pain or flare-up. Patients regard these complications as a benchmark for the assessment of clinician's abilities. In this context, the evidence for recommending either one- or two-visit RCT is not consistent. Aims: This study aims to compare the prevalence of postoperative pain and tenderness to percussion after single-visit (SV) versus two-visit RCT on the mandibular first molar. Materials and Methods: The study was registered with www.ctri.nic.in (CTRI/2019/05/019067). Seventy individuals requiring RCT on a mandibular first molar were selected and randomly ascribed to either single- (Group 1, n = 35) or two-visit RCT (Group 2, n = 35). Postoperative pain levels were assessed using heft parker visual analog scale. The treated teeth were appraised for tenderness to percussion after 1 week of obturation. Statistical Analysis: Thirty-four patients were evaluated in each group: One patient, each, dropped out from both the groups. The data analysis was done using Student's t-test and Chi-square test. Results and Conclusion: Pain score in multiple-visit (MV) was significantly higher than SV after 12- (P = 0.039) and 48 h (P = 0.043). Short-term postoperative pain was higher in MV than SV RCT of mandibular first molar teeth.

Directional, Low-Energy Driven Thermal Actuating Bilayer Enabled by Coordinated Submolecular Switching.

The authors reveal a thermal actuating bilayer that undergoes reversible deformation in response to low-energy thermal stimuli, for example, a few degrees of temperature increase. It is made of an aligned carbon nanotube (CNT) sheet covalently connected to a polymer layer in which dibenzocycloocta-1,5-diene (DBCOD) actuating units are oriented parallel to CNTs. Upon exposure to low-energy thermal stimulation, coordinated submolecular-level conformational changes of DBCODs result in macroscopic thermal contraction. This unique thermal contraction offers distinct advantages. It's inherently fast, repeatable, low-energy driven, and medium independent. The covalent interface and reversible nature of the conformational change bestow this bilayer with excellent repeatability, up to at least 70 000 cycles. Unlike conventional CNT bilayer systems, this system can achieve high precision actuation readily and can be scaled down to nanoscale. A new platform made of poly(vinylidene fluoride) (PVDF) in tandem with the bilayer can harvest low-grade thermal energy and convert it into electricity. The platform produces 86 times greater energy than PVDF alone upon exposure to 6 °C thermal fluctuations above room temperature. This platform provides a pathway to low-grade thermal energy harvesting. It also enables low-energy driven thermal artificial robotics, ultrasensitive thermal sensors, and remote controlled near infrared (NIR) driven actuators.

Cervical Dystonia Refractory to Botulinum Toxin Responding to Radiofrequency Ablation: A Case Report.

A 62-year-old male diagnosed with cervical dystonia (CD) and chronic right-sided neck pain presented to the Pain Clinic after his pain and CD symptoms failed to resolve with botulinum toxin therapy. During clinical examination, right C3-C4 and C4-C5 facet arthropathy was suspected. After two sets of diagnostic right cervical, C3, C4, and C5 medial branch blocks provided >80% pain relief; cervical radiofrequency ablation (CRFA) was performed. Post CRFA, the patient was followed for 12 months. Till the last follow-up, he was not only experiencing 90% pain relief, but also had significant improvement in his CD symptoms to the point that he no longer needed botulinum toxin and other CD-related therapy. This report suggests that large-scale research is required to postulate whether CD patients, whose symptoms are refractory to botulinum toxin, should be routinely screened for cervical facet arthropathy. This is the first reported case of improvement in CD symptoms with CRFA. This effect could be explained by the fact that certain deep cervical muscles, which are affected in CD, are innervated by medial branch nerves.

Prediction of survival outcome based on clinical features and pretreatment 18FDG-PET/CT for HNSCC patients.

BACKGROUND AND OBJECTIVE: In this study, we have analysed pretreatment positron-emission tomography/ computed tomography (PET/CT) images of head and neck squamous cell carcinoma (HNSCC) patients. We have used a publicly available dataset for our analysis. The clinical features of the patient, PET quantitative parameters, and textural indices from pretreatment PET-CT images are selected for the study. The main objective of the study is to use classifiers to predict the outcome for HNSCC patients and compare the performance of the model with the conventional statistical model (CoxPH). METHODS: We have applied a 40% fixed SUV threshold method for tumour delineation. Clinical features of each patient are provided in the dataset, and other features are calculated using LIFEx software. For predicting the outcome, we have implemented three classifiers - Random Forest classifier, Gradient Boosted Decision tree (GBDT) and Decision tree classifier. We have trained each model using 93 data points and test the model performance using 39 data points. The best model - GBDT is chosen based on the performance metrics. RESULTS: It is observed that typically three features: MTV (Metabolic tumour Volume), primary tumour site and GLCM_correlation are significant for prediction of survival outcome. For testing cohort, GBDT achieves a balanced accuracy of 88%, where conventional statistical model reported a balanced accuracy of 81.5%. CONCLUSIONS: The proposed classifier achieves higher accuracy than the state of the art technique. Using this classifier we can estimate the HNSCC patient's outcome, and depending upon the outcome treatment policy can be selected.

Low-Temperature Energy Transfer via Self-Trapped Excitons in Mn2+-Doped 2D Organometal Halide Perovskites.

We investigate the mechanisms of energy transfer in Mn2+-doped ethylammonium lead bromide (EA2PbBr4:Mn2+), a two-dimensional layered perovskite (2DLP), using cryogenic optical spectroscopy. At temperature T > 120 K, photoluminescence (PL) is dominated by emission from Mn2+, with complete suppression of band edge (BE) emission and self-trapped exciton (STE) emission. However, for T < 120 K, in addition to Mn2+ emission, PL is observed from BE and STEs. Data further reveal that for 20 K < T < 120 K, STEs form the most dominant routes in assisting energy transfer (ET) from 2DLP to Mn2+ dopants. However, at higher Mn2+ concentration, higher activation energies indicate defect states come into play, successfully competing with STEs for ET both from BE to STE states and from STE to Mn2+. Finally, using polarization-resolved spectroscopy, we demonstrate optical spin orientation of the Mn2+ ions via ET from 2DLP excitons at zero magnetic field. Our results reveal fundamental insights on the interactions between quantum confined charge carriers and dopants in organometal halide perovskites.

Modulating Charge Carrier Dynamics and Transfer via Surface Modifications in Organometallic Halide Perovskite Quantum Dots.

We investigate the effect of functionalization by acid/amine combinations of four aromatic capping ligands on the optoelectronic properties of CH3NH3PbBr3 perovskite quantum dots (PQDs). These include benzoic acid (BA), phenylacetic acid (PAA), benzylamine, and isopropyl benzylamine. We observe that charge transfer efficiency in PQD films comprising BA-ligated samples varies between 12% and 95% as the dot density is tuned from 102 to 105 dots/µm2 but is consistently ∼92% over that entire range for PAA-ligated PQDs. As temperature T decreases, initially, recombination is dominated by bound or trapped excitons, but below 80 K, spectral broadening, accompanied by free excitonic behavior, is observed. Our results indicate enhanced charge delocalization at lower values of T, which reduces the level of exciton confinement and recombination decay rates and underlines the importance of investigating PQD-ligand interactions at a fundamental level given the significant effect minute changes in ligand structures have on the optoelectronic properties of quantum dots.