Experimental Confirmation of van der Waals-Enhanced Growth of Sulfuric Acid/Water Nanoparticles.

Since the size of an atmospheric particle determines many of its effects, we conducted experiments to better understand their rate of growth. Seed particles composed of sulfuric acid and water were exposed to photolytically generated HSO molecules and their change in size was monitored with a mobility particle system. HSO production rates were held steady while the seed particle diameter was varied from 3 to 25 nm to explore how growth is affected by size.

Semiempirical HSO-HO Cluster Standard Gibbs Reaction Energies from Nucleation Experiments: Improved Temperature Dependence.

The thermodynamics of sulfuric acid-water clusters is important for modeling new particle formation in the atmosphere. Particle number densities obtained at 296 K from a photolytic flow reactor are greatly overpredicted by the Sulfuric Acid Water Nucleation (SAWNUC) model. Empirical, temperature-dependent adjustments to the SAWNUC model allow for better agreement with the data obtained at 296 K, while maintaining reasonable agreement with the data of Hanson and Lovejoy at 242 K.

The Relationship Between Perceived Parenting Style and Social Anxiety: A Meta-analysis of Mainland Chinese Students.

Previous research on the relationship between parenting style and social anxiety in Chinese youth has been inconsistent, which has made it difficult to consider whether improving parenting may serve as a preventative intervention for social anxiety. The current study aimed to clarify these inconsistencies by examining the strength of the association between positive/negative parenting style and social anxiety among Chinese students and the role of certain moderators in those associations. A meta-analysis was conducted on 53 studies with a total sample of 26,024 Chinese mainland students.

Social change at the local level: A psychobiography of Khali Sweeney from Detroit's downtown boxing gym.

Objective: This psychobiography analyzes the life of Khali Sweeney from Detroit's Downtown Boxing Gym to understand his motivation for and methods as a social change agent. In doing so, the project also considers how to prepare the next generation of youth development leaders as social change agents.

Method: We conducted a nine-step psychobiography based on recommendations from established psychobiographical methods.

Stepping in and up to meet community needs: How community-based college access and success programs responded to COVID-19.

The current study uplifts the efforts of community-based college access and success programs (CAS) to support the college preparation, matriculation, and persistence of underserved students during COVID-19. Fifty-eight CAS across the United States completed an online survey that gathered information about organizational demographics, COVID-19 challenges, responses to challenges, and communication with constituents and funding needs during COVID-19. Results suggested CAS faced multiple challenges due to COVID-19 that affected the organization, staff, and constituents.

Using participatory culture-specific consultation to support the mental health needs of summer camp staff.

Nearly 30% of all U.S. youth attend summer camp each year, making it one of the broadest reaching out-of-school-time interventions in the country.

Developmental assessment and early intervention for children with developmental delays: A case study in South Australia.

Background: Child development monitoring and screening have been mandated as a national health service worldwide, including Indonesia; however, a recent study found that Indonesian community health nurses experienced difficulties detecting and stimulating a child suspected of a developmental delay.

Objective: To explore and provide an example of how Australian community health nurses, along with other professionals, contribute to a Universal child and family health service (UCFHS), a similar programme name in Indonesia is child developmental stimulating, detecting monitoring and early intervention programme or SDIDTK.

Case Study: This is a case study of a young Australian boy (4 years old) whom the mother reported that her son has unclear speech and he was not speaking as much as other children at his age.

Early-Onset Familial Alzheimer Disease Variant PSEN2 N141I Heterozygosity is Associated with Altered Microglia Phenotype.

Background: Early-onset familial Alzheimer disease (EOFAD) is caused by heterozygous variants in the presenilin 1 (PSEN1), presenilin 2 (PSEN2), and APP genes. Decades after their discovery, the mechanisms by which these genes cause Alzheimer's disease (AD) or promote AD progression are not fully understood. While it is established that presenilin (PS) enzymatic activity produces amyloid-β (Aβ), PSs also regulate numerous other cellular functions, some of which intersect with known pathogenic drivers of neurodegeneration.

Modulation of Hematopoietic Lineage Specification Impacts TREM2 Expression in Microglia-Like Cells Derived From Human Stem Cells.

Microglia are the primary innate immune cell type in the brain, and their dysfunction has been linked to a variety of central nervous system disorders. Human microglia are extraordinarily difficult to obtain for experimental investigation, limiting our ability to study the impact of human genetic variants on microglia functions. Previous studies have reported that microglia-like cells can be derived from human monocytes or pluripotent stem cells.

First Evidence of Vibrationally Driven Bimolecular Reactions in Solution: Reactions of Br Atoms with Dimethylsulfoxide and Methanol.

We present evidence for vibrational enhancement of the rate of bimolecular reactions of Br atoms with dimethylsulfoxide (DMSO) and methanol (CHOH) in the condensed phase. The abstraction of a hydrogen atom from either of these solvents by a Br atom is highly endoergic: 3269 cm for DMSO and 1416 or 4414 cm for CHOH, depending on the hydrogen atom abstracted. Thus, there is no thermal abstraction reaction at room temperature.

Solvent Dependent Dynamics of Salicylidene Aniline in Binary Mixtures of Supercritical CO with 1-Propanol or Cyclohexane.

The role of different solvent environments in determining the behavior of molecules in solution is a fundamental aspect of chemical reactivity. We present an approach for exploring the influence of solvent properties on condensed-phase dynamics using ultrafast transient absorption spectroscopy in supercritical CO. Using supercritical CO permits adjustment of the density, by varying the temperature and pressure, whereas varying the concentration or identity of a second solvent, the cosolvent, in a binary mixture allows for adjustments of the degree of interaction between the solute and the solvent.

Dynamics and yields for CHBrCl photodissociation from 215-265 nm.

We investigate the Ã-band photodissociation of CHBrCl at 215, 225, 235, 245, 255, and 265 nm. Following C-Br bond cleavage, resonance enhanced multiphoton ionization and time of flight mass spectrometry provide selective detection of the two product channels, from which we quantify the relative quantum yield of Br/Br* production. Velocity-map imaging of the photofragments allows us to determine the energy partitioning as a function of the photolysis energy for different exit channels.

Comparative Study of Cl-Atom Reactions in Solution Using Time-Resolved Vibrational Spectroscopy.

A Cl atom can react with 2,3-dimethylbutane (DMB), 2,3-dimethyl-2-butene (DMBE), and 2,5-dimethyl-2,4-hexadiene (DMHD) in solution via a hydrogen-abstraction reaction. The large exoergicity of the reaction between a Cl atom and alkenes (DMBE and DMHD) makes vibrational excitation of the HCl product possible, and we observe the formation of vibrationally excited HCl (v = 1) for both reactions. In CCl4, the branching fractions of HCl (v = 1), Γ (v = 1), for the Cl-atom reactions with DMBE and DMHD are 0.

Loss of endophilin-B1 exacerbates Alzheimer's disease pathology.

Endophilin-B1, also known as Bax-interacting factor 1 (Bif-1, and encoded by SH3GLB1), is a multifunctional protein involved in apoptosis, autophagy and mitochondrial function. We recently described a unique neuroprotective role for neuron-specific alternatively spliced isoforms of endophilin-B1. To examine whether endophilin-B1-mediated neuroprotection could be a novel therapeutic target for Alzheimer's disease we used a double mutant amyloid precursor protein and presenilin 1 (APPswe/PSEN1dE9) mouse model of Alzheimer's disease and observed that expression of neuron-specific endophilin-B1 isoforms declined with disease progression.

Recombinant adeno-associated viral (rAAV) vectors mediate efficient gene transduction in cultured neonatal and adult microglia.

Microglia are a specialized population of myeloid cells that mediate CNS innate immune responses. Efforts to identify the cellular and molecular mechanisms that regulate microglia behaviors have been hampered by the lack of effective tools for manipulating gene expression. Cultured microglia are refractory to most chemical and electrical transfection methods, yielding little or no gene delivery and causing toxicity and/or inflammatory activation.

Vibrational predissociation and vibrationally induced isomerization of 3-aminophenol-ammonia.

We investigate the vibrational predissociation dynamics of the hydrogen-bonded 3-aminophenol-ammonia cluster (3-AP-NH3) in the OH and NH stretching regions. Vibrational excitation provides enough energy to dissociate the cluster into its constituent 3-AP and NH3 monomers, and we detect the 3-AP fragments via (1 + 1) resonance-enhanced multiphoton ionization (REMPI). The distribution of vibrational states of the 3-AP fragment suggests the presence of two distinct dissociation pathways.

Electronic states of the quasilinear molecule propargylene (HCCCH) from negative ion photoelectron spectroscopy.

We use gas-phase negative ion photoelectron spectroscopy to study the quasilinear carbene propargylene, HCCCH, and its isotopologue DCCCD. Photodetachment from HCCCH– affords the X̃(3B) ground state of HCCCH and its ã(1A), b̃ (1B), d̃(1A2), and B̃(3A2) excited states. Extended, negatively anharmonic vibrational progressions in the X̃(3B) ground state and the open-shell singlet b̃ (1B) state arise from the change in geometry between the anion and the neutral states and complicate the assignment of the origin peak.

Presenilin 2 influences miR146 level and activity in microglia.

Microglia, the resident innate immune cells of the CNS, are the primary defenders against microbes and critical to CNS remodeling. Dysregulation of microglial behavior can lead to unchecked pro-inflammatory activity and subsequent neurodegeneration. The molecular mechanisms leading to chronic inflammation and microglial dysfunction in neurodegenerative diseases are not well-understood.

Photofragmentation dynamics of ICN(-)(CO2)n clusters following visible excitation.

Photodissociation of ICN(-)(CO2)n, n = 0-18, with 500-nm excitation is investigated using a dual time-of-flight mass spectrometer. Photoabsorption to the (2)Π(1/2) state is detected using ionic-photoproduct action spectroscopy; the maximum absorption occurs around 490 nm. Ionic-photoproduct distributions were determined for ICN(-)(CO2)n at 500 nm.

Ground and low-lying excited states of propadienylidene (H2C=C=C:) obtained by negative ion photoelectron spectroscopy.

A joint experimental-theoretical study has been carried out on electronic states of propadienylidene (H(2)CCC), using results from negative-ion photoelectron spectroscopy. In addition to the previously characterized X(1)A(1) electronic state, spectroscopic features are observed that belong to five additional states: the low-lying ã(3)B(1) and b(3)A(2) states, as well as two excited singlets, Ã(1)A(2) and B(1)B(1), and a higher-lying triplet, c(3)A(1). Term energies (T(0), in cm(-1)) for the excited states obtained from the data are: 10,354±11 (ã(3)B(1)); 11,950±30 (b(3)A(2)); 20,943±11 (c(3)A(1)); and 13,677±11 (Ã(1)A(2)).

Determining the dissociation threshold of ammonia trimers from action spectroscopy of small clusters.

Infrared-action spectroscopy of small ammonia clusters obtained by detecting ammonia fragments from vibrational predissociation provides an estimate of the dissociation energy of the trimer. The product detection uses resonance enhanced multiphoton ionization (REMPI) of individual rovibrational states of ammonia identified by simulations using a consistent set of ground-electronic-state spectroscopic constants in the PGOPHER program. Comparison of the infrared-action spectra to a less congested spectrum measured in He droplets [M.

New view of the ICN A continuum using photoelectron spectroscopy of ICN-.

Negative-ion photoelectron spectroscopy of ICN(-) (X̃ (2)Σ(+)) reveals transitions to the ground electronic state (X̃ (1)Σ(+)) of ICN as well as the first five excited states ((3)Π(2), (3)Π(1), Π(0(-) ) (3), Π(0(+) ) (3), and (1)Π(1)) that make up the ICN A continuum. By starting from the equilibrium geometry of the anion, photoelectron spectroscopy characterizes the electronic structure of ICN at an elongated I-C bond length of 2.65 Å.