1,014 results match your criteria: "University of California-Merced[Affiliation]"

Easily accessible methods for direct C-H arylation of arenes have been explored in the presence of transition metal catalysts to facilitate C-C bond formation; however, the absence of transition-metal impurities is a significant concern in the preparation of active pharmaceutical ingredients (APIs). Herein, we examine the use of bis(imino)acenaphthene (BIAN) as a potential single-electron transfer initiator in transition metal-free C-C bond-forming reactions. Using this approach, arenes are coupled to several aryl and heteroaryl halides.

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Predictions of rhizosphere microbiome dynamics with a genome-informed and trait-based energy budget model.

Nat Microbiol

February 2024

Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.

Article Synopsis
  • Soil microbiomes are made up of many different types of tiny living things (microbes) that help with things like plant growth and nutrient cycling.
  • Scientists are using information from the genes of these microbes to understand how they behave and interact when they break down different materials in the soil.
  • By studying these interactions, researchers found out that some bacteria can grow slower but use carbon more efficiently, which helps keep important nutrients in the soil.
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Shear-activation of mechanochemical reactions through molecular deformation.

Sci Rep

February 2024

Department of Mechanical Engineering, University of California Merced, 5200 N. Lake Road, Merced, CA, 95343, USA.

Mechanical stress can directly activate chemical reactions by reducing the reaction energy barrier. A possible mechanism of such mechanochemical activation is structural deformation of the reactant species. However, the effect of deformation on the reaction energetics is unclear, especially, for shear stress-driven reactions.

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Autonomous out-of-equilibrium agents or cells in suspension are ubiquitous in biology and engineering. Turning chemical energy into mechanical stress, they generate activity in their environment, which may trigger spontaneous large-scale dynamics. Often, these systems are composed of multiple populations that may reflect the coexistence of multiple species, differing phenotypes, or chemically varying agents in engineered settings.

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As environmental flow demands become better characterized, improved water allocation and reservoir operating solutions can be devised to meet them. However, significant economic trade-offs are still expected, especially in hydropower-dominated basins. This study explores the use of the electricity market as both an institutional arrangement and an alternative financing source to handle the costs of implementing environmental flows in river systems managed for hydropower benefits.

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This paper examines the relationship between immigration enforcement and institutionalization rates of the elderly. Exploiting the staggered implementation of the Secure Communities (SC) immigration enforcement program across U.S.

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Article Synopsis
  • Soil plays a key role in the global carbon cycle, and understanding both the quantity and longevity of carbon stored in soils is crucial, especially in less studied regions like sub-Saharan Africa.
  • Previous research has predominantly focused on temperate regions, leaving gaps in knowledge regarding soil carbon dynamics in diverse climates and mineral compositions, which this study aims to address.
  • The findings reveal that organic carbon in moderately weathered soils in seasonal zones persists longer than in highly weathered soils in humid areas, with arid regions showing similar persistence to seasonal zones, suggesting that soil classification based on climatic conditions can enhance predictions of soil behavior under climate change.
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The carbapenemase (KPC) β-Lactamase Has Evolved in Response to Ceftazidime Avibactam.

Antibiotics (Basel)

December 2023

Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA 95343, USA.

carbapenemase KPC is an important resistance gene that has disseminated globally in response to carbapenem use. It is now being implicated as a resistance determinant in Ceftazidime Avibactam (CAZ-AVI) resistance. Given that CAZ-AVI is a last-resort antibiotic, it is critical to understand how resistance to this drug is evolving.

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The valid assessment of vocabulary development in dual-language-learning infants is critical to developmental science. We developed the Dual Language Learners English-Spanish (DLL-ES) Inventories to measure vocabularies of U.S.

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Hedgehog Signaling in Cortical Development.

Cells

December 2023

Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA 95340, USA.

The Hedgehog (Hh) pathway plays a crucial role in embryonic development, acting both as a morphogenic signal that organizes tissue formation and a potent mitogenic signal driving cell proliferation. Dysregulated Hh signaling leads to various developmental defects in the brain. This article aims to review the roles of Hh signaling in the development of the neocortex in the mammalian brain, focusing on its regulation of neural progenitor proliferation and neuronal production.

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The inner workings of an ancient biological clock.

Trends Biochem Sci

March 2024

Center for Circadian Biology, University of California - San Diego, La Jolla, CA 92093, USA; Department of Chemistry & Biochemistry, University of California - Santa Cruz, Santa Cruz, CA 95064, USA. Electronic address:

Article Synopsis
  • Circadian clocks have evolved in various organisms to adapt to daily changes in light and temperature due to Earth's rotation, helping synchronize behavior and physiology with environmental rhythms.
  • The cyanobacterial clock is a key model for studying circadian rhythms, as it can be fully reconstructed outside of living organisms.
  • Recent advancements in biochemical, biophysical, and mathematical techniques have improved our understanding of the molecular mechanisms of cyanobacterial Kai proteins, offering insights that may help answer ongoing questions in circadian biology.
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Although COVID-19 transmission has been reduced by the advent of vaccinations and a variety of rapid monitoring techniques, the SARS-CoV-2 virus itself has shown a remarkable ability to mutate and persist. With this long track record of immune escape, researchers are still exploring prophylactic treatments to curtail future SARS-CoV-2 variants. Specifically, much focus has been placed on the antiviral lectin Griffithsin in preventing spike protein-mediated infection via the hACE2 receptor (direct infection).

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Non-specific cargo-filament interactions slow down motor-driven transport.

Eur Phys J E Soft Matter

December 2023

Department of Physics, University of California, Merced, 5200 North Lake Rd, Merced, CA, 95343, USA.

Article Synopsis
  • Active cargo transport within cells is essential for various functions, but the crowded cellular environment can create weak, non-specific interactions that hinder movement.
  • In experiments using quantum dot cargo with different numbers of kinesin motors, it was found that cargo moved slower with single motors, but speed improved when multiple motors were attached.
  • A computational model was developed to understand these interactions, showing that non-specific binding can slow down transport, while using multiple motors can help mitigate these effects and enhance cargo velocity.
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To survive extreme drying (anhydrobiosis), many organisms, spanning every kingdom of life, accumulate intrinsically disordered proteins (IDPs). For decades, the ability of anhydrobiosis-related IDPs to form transient amphipathic helices has been suggested to be important for promoting desiccation tolerance. However, evidence empirically supporting the necessity and/or sufficiency of helicity in mediating anhydrobiosis is lacking.

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Reactive Simulations of Silica Functionalization with Aromatic Hydrocarbons.

Langmuir

January 2024

Department of Mechanical Engineering, University of California Merced, 5200 N. Lake Road, Merced, California 95343, United States.

Reactive molecular dynamics simulations are used to model the covalent functionalization of amorphous silica with aromatic hydrocarbons. Simulations show that the surface density of silanol-terminated phenyl, naphthyl, and anthracenyl molecules is lower than the maximum value calculated based on molecule geometry, and the simulation densities decrease faster with the number of aromatic rings than the geometric densities. The trends are analyzed in terms of the surface-silanol bonding configurations, tilt angles, local conformational ordering, and aggregation of surface-bound molecules under steady-state conditions.

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Chemosensory scientists have been skeptical that reports of COVID-19 taste loss are genuine, in part because before COVID-19 taste loss was rare and often confused with smell loss. Therefore, to establish the predicted prevalence rate of taste loss in COVID-19 patients, we conducted a systematic review and meta-analysis of 376 papers published in 2020-2021, with 235 meeting all inclusion criteria. Drawing on previous studies and guided by early meta-analyses, we explored how methodological differences (direct vs.

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Social influence aligns people's opinions, but social identities and related in-group biases interfere with this alignment. For instance, the recent rise of young climate activists (e.g.

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New formulations of Amphotericin-B (Am-B), the most popular therapeutic drug for many human infections such as parasitic and fungal pathogens, are safe, economical, and effective in the world. Several newly designed carrier systems for Am-B can also be considered orally with sufficient gastrointestinal permeability and good solubility. However, the clinical application of several new formulations of Am-B with organ cytotoxicity, low bioavailability, high costs, and technical problems have caused some issues.

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The growth of protective tribofilms from lubricant antiwear additives on rubbing surfaces is initiated by mechanochemically promoted dissociation reactions. These processes are not well understood at the molecular scale for many important additives, such as tricresyl phosphate (TCP). One aspect that needs further clarification is the extent to which the surface properties affect the mechanochemical decomposition.

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Viruses are the most numerically abundant biological entities on Earth. As ubiquitous replicators of molecular information and agents of community change, viruses have potent effects on the life on Earth, and may play a critical role in human spaceflight, for life-detection missions to other planetary bodies and planetary protection. However, major knowledge gaps constrain our understanding of the Earth's virosphere: (1) the role viruses play in biogeochemical cycles, (2) the origin(s) of viruses and (3) the involvement of viruses in the evolution, distribution and persistence of life.

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Background: Among emerging adults with type 1 diabetes (T1D), self-regulation and social regulation skills can help avoid high A1c and diabetes distress. FAMS (Family/friend Activation to Motivate Self-care) is mobile phone-delivered intervention that supports development of these skills and is efficacious among adults with type 2 diabetes. However, the acceptability and feasibility of the FAMS intervention among emerging adults with T1D is unknown.

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Assembly mechanism of the inflammasome sensor AIM2 revealed by single molecule analysis.

Nat Commun

December 2023

Department of Bioengineering, School of Engineering, University of California Merced, Merced, California, USA.

Pathogenic dsDNA prompts AIM2 assembly leading to the formation of the inflammasome, a multimeric complex that triggers the inflammatory response. The recognition of foreign dsDNA involves AIM2 self-assembly concomitant with dsDNA binding. However, we lack mechanistic and kinetic information on the formation and propagation of the assembly, which can shed light on innate immunity's time response and specificity.

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Sensory organs must develop alongside the skull within which they are largely encased, and this relationship can manifest as the skull constraining the organs, organs constraining the skull, or organs constraining one another in relative size. How this interplay between sensory organs and the developing skull plays out during the evolution of sensory diversity; however, remains unknown. Here, we examine the developmental sequence of the cochlea, the organ responsible for hearing and echolocation, in species with distinct diet and echolocation types within the ecologically diverse bat super-family Noctilionoidea.

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Due to global warming, there evolves a global consensus and urgent need on carbon emission mitigations, especially in developing countries. We investigated the spatiotemporal characteristics of carbon emissions induced by land use change in Shaanxi at the city level, from 2000 to 2020, by combining direct and indirect emission calculation methods with correction coefficients. In addition, we evaluated the impact of 10 different factors through the geodetector model and their spatial heterogeneity with the geographic weighted regression (GWR) model.

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Binding of small molecule inhibitors to RNA polymerase-Spt5 complex impacts RNA and DNA stability.

J Comput Aided Mol Des

November 2023

Department of Molecular and Cell Biology, University of California Merced, 5200 North Lake Rd, Merced, CA, 95343, USA.

Spt5 is an elongation factor that associates with RNA polymerase II (Pol II) during transcription and has important functions in promoter-proximal pausing and elongation processivity. Spt5 was also recognized for its roles in the transcription of expanded-repeat genes that are related to neurodegenerative diseases. Recently, a set of Spt5-Pol II small molecule inhibitors (SPIs) were reported, which selectively inhibit mutant huntingtin gene transcription.

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