Protocol for effective surface passivation for single-molecule studies of chromatin and topoisomerase II.

For single-molecule studies requiring surface anchoring of biomolecules, poorly passivated surfaces can result in alterations of biomolecule structure and function that lead to artifacts. Here, we present a surface passivation assay for single-molecule studies of chromatin and topoisomerase II. We detail steps for preparing a nucleosome array and hydrophobic nitrocellulose-coated flow cell.

Maladaptive but malleable: Gender-science stereotypes emerge early but are modifiable by language.

Gender-science stereotypes emerge early in childhood, but little is known about the developmental processes by which they arise. The present study tested the hypothesis that language implying scientists are a special and distinct kind of person contributes to the development of gender-science stereotypes, even when it does not communicate stereotypic content. One cross-sectional and two longitudinal studies with racially and geographically diverse children (primarily from the United States; ages 4-5; N = 872, tested 2020-2022) revealed that gender stereotypes about science versus art (a) emerge before elementary school, (b) arise from commonplace identity-emphasizing language, especially among girls, and (c) can be durably disrupted by subtle changes to language.

Tunable elliptical cylinders for rotational mechanical studies of single DNA molecules.

The angular optical trap (AOT) is a powerful technique for measuring the DNA topology and rotational mechanics of fundamental biological processes. Realizing the full potential of the AOT requires rapid torsional control of these processes. However, existing AOT quartz cylinders are limited in their ability to meet the high rotation rate requirement while minimizing laser-induced photodamage.

Artificial Intelligence to Diagnose Complications of Diabetes.

Artificial intelligence (AI) is increasingly being used to diagnose complications of diabetes. Artificial intelligence is technology that enables computers and machines to simulate human intelligence and solve complicated problems. In this article, we address current and likely future applications for AI to be applied to diabetes and its complications, including pharmacoadherence to therapy, diagnosis of hypoglycemia, diabetic eye disease, diabetic kidney diseases, diabetic neuropathy, diabetic foot ulcers, and heart failure in diabetes.

How Culture Shapes the Early Development of Essentialist Beliefs.

People represent many categories and their features as determined by intrinsic essences. These essentialist beliefs reflect biased views of the world that can hinder scientific reasoning and contribute to social prejudice. To consider the extent to which such essentialist views originate from culturally-situated processes, the present study tested the developmental trajectories of essentialist beliefs among children growing up in the United States and China (N = 531; ages 3-6).

Effortful control is associated with ethnic minority children's pro-wealth biases and explanations across social domains.

Children's tendency to prefer rich to poor people and to view wealthy individuals more positively has been well-documented, but little is known about (a) the mechanisms underlying this "pro-wealth" bias and (b) the extent to which it holds across various social domains (e.g., friendships vs.

Chromatin Buffers Torsional Stress During Transcription.

Transcription through chromatin under torsion represents a fundamental problem in biology. Pol II must overcome nucleosome obstacles and, because of the DNA helical structure, must also rotate relative to the DNA, generating torsional stress. However, there is a limited understanding of how Pol II transcribes through nucleosomes while supercoiling DNA.

Human Topoisomerase IIα Promotes Chromatin Condensation Via a Phase Transition.

Topoisomerase II (topo II) enzymes are essential enzymes known to resolve topological entanglements during DNA processing. Curiously, while yeast expresses a single topo II, humans express two topo II isozymes, topo IIα and topo IIβ, which share a similar catalytic domain but differ in their intrinsically disordered C-terminal domains (CTDs). During mitosis, topo IIα and condensin I constitute the most abundant chromosome scaffolding proteins essential for chromosome condensation.

Torsion is a Dynamic Regulator of DNA Replication Stalling and Reactivation.

The inherent helical structure of DNA dictates that a replisome must rotate relative to DNA during replication, presenting inevitable topological challenges to replication. However, little is known about how the replisome progresses against torsional stress. Here, we developed a label-free, high-resolution, real-time assay to monitor replisome movement under torsion.

Torsional Mechanics of Circular DNA.

Circular DNA found in the cell is actively regulated to an underwound state, with their superhelical density close to . While this underwound state is essential to life, how it impacts the torsional mechanical properties of DNA is not fully understood. In this work, we performed simulations to understand the torsional mechanics of circular DNA and validated our results with single-molecule measurements and analytical theory.

DNA Polymerase Locks Replication Fork Under Stress.

Replication of DNA requires the parental DNA to be unwound to allow the genetic information to be faithfully duplicated by the replisome. While this function is usually shared by a host of proteins in the replisome, notably DNA polymerase (DNAP) and helicase, the consequence of DNAP synthesizing DNA while decoupled from helicase remains not well understood. The unwinding of downstream DNA poses significant stress to DNAP, and the interaction between DNAP and the replication fork may affect replication restart.

Geometry of Braided DNA Dictates Supercoiling Partition.

During DNA replication, the replisome must rotate relative to the DNA substrate, generating supercoiling that must be partitioned in front of or behind the replisome. Supercoiling partitioned behind the replisome may intertwine (or braid) daughter DNA molecules and restrict chromosome segregation. Supercoiling partitioning and torsional resistance at the replisome should depend on the geometry of the two daughter DNA molecules, determined by their end separations.

An Effective Surface Passivation Assay for Single-Molecule Studies of Chromatin and Topoisomerase II.

Unlabelled: For complete details on the use and execution of this protocol, please refer to Le et al. (2019).

Summary: A.

Tunable Elliptical Cylinders for Rotational Mechanical Studies of Single DNA Molecules.

The angular optical trap (AOT) is a powerful technique for measuring the DNA topology and rotational mechanics of fundamental biological processes. Realizing the full potential of the AOT requires rapid torsional control of these processes. However, existing AOT quartz cylinders are limited in their ability to meet the high rotation rate requirement while minimizing laser-induced photodamage.

Exploration of the tunability of BRD4 degradation by DCAF16 trans-labelling covalent glues.

Chemically induced proximity modalities such as targeted protein degradation (TPD) hold promise for expanding the number of proteins that can be manipulated pharmacologically. However, current TPD strategies are often limited to proteins with preexisting ligands. Molecular glues (e.

and analyses of the role of the Prc protease in inducing mucoidy in .

Unlabelled: In , alginate biosynthesis gene expression is inhibited by the transmembrane anti-sigma factor MucA, which sequesters the AlgU sigma factor. Cell envelope stress initiates cleavage of the MucA periplasmic domain by site-1 protease AlgW, followed by further MucA degradation to release AlgU. However, after colonizing the lungs of people with cystic fibrosis, converts to a mucoid form that produces alginate constitutively.

Post-Artesunate Delayed Hemolysis in Pediatric Malaria Patients in the United States.

Post-artesunate delayed hemolysis (PADH) occurred in 6 of 24 children treated with artesunate for severe malaria in the United States; however, severe hemolysis requiring hospitalization or transfusion was rare. In children in the United States treated with artesunate, counseling, and symptom monitoring may be preferred to weekly laboratory surveillance for PADH.

Template-assisted covalent modification underlies activity of covalent molecular glues.

Molecular glues are proximity-inducing small molecules that have emerged as an attractive therapeutic approach. However, developing molecular glues remains challenging, requiring innovative mechanistic strategies to stabilize neoprotein interfaces and expedite discovery. Here we unveil a trans-labeling covalent molecular glue mechanism, termed 'template-assisted covalent modification'.

Epidemiology and risk stratification of young infants presenting to the emergency department with hypothermia.

Objective: Hypothermic infants are presumed to be at high risk for a serious bacterial infection (SBI) or herpes simplex virus (HSV) infection. In contrast to febrile infants, the emergency department (ED) management of hypothermic infants is variable in the absence of consensus guidelines, potentially resulting in low-value care and missed diagnoses. We investigated the diagnostic workup conducted for hypothermic infants in our academic pediatric ED, the incidence of SBI and HSV infection, and risk factors associated with infection.

The effects of Asian American Pacific Islander (AAPI) data inequities in gynecologic oncology.

Asian American and Pacific Islanders (AAPI) are the fastest growing racial group in the United States. Data on AAPI communities, however, are significantly limited. The oversimplification and underreporting of this ethnically and socioeconomically heterogenous population through the use of aggregated data has deleterious effects and worsens disparities in patient treatment, outcomes, and experiences.