Synthetic pathways to create asymmetric center at C1 position of 1-substituted-tetrahydro-β-carbolines - a review.

The 2,3,4,9-tetrahydro-1-pyrido[3,4-]indoles or tetrahydro-β-carbolines (THβCs) are tricyclic compounds that are found in various natural sources that exhibit a wide range of important pharmacological activities. Chiral 1-substituted-THβCs, which have an asymmetric center at C1, have attained significant interest due to their possible Monoamine Oxidase (MAO) inhibitory activity, benzodiazepine receptor binding activity, and antimalarial effectiveness against chloroquine-resistant . This review highlights and summarizes various novel stereoselective approaches to introduce chirality at the C1 position of 1-substituted-THβCs in good yield and enantiomeric excess (ee) or diastereomeric excess (de).

Extreme specificity in obligate mutualism-A role for competition?

Obligate mutualisms, reciprocally obligate beneficial interactions, are some of the most important mutualisms on the planet, providing the basis for the evolution of the eukaryotic cell, the formation and persistence of terrestrial ecosystems and the establishment and expansion of coral reefs. In addition, these mutualisms can also lead to the diversification of interacting partner species. Accompanying this diversification is a general pattern of a high degree of specificity among interacting partner species.

AI-organoid integrated systems for biomedical studies and applications.

In this review, we explore the growing role of artificial intelligence (AI) in advancing the biomedical applications of human pluripotent stem cell (hPSC)-derived organoids. Stem cell-derived organoids, these miniature organ replicas, have become essential tools for disease modeling, drug discovery, and regenerative medicine. However, analyzing the vast and intricate datasets generated from these organoids can be inefficient and error-prone.

Inserting an "atomic trap" for directional dopant migration in core/multi-shell quantum dots.

Diffusion of atoms or ions in solid crystalline lattice is crucial in many areas of solid-state technology. However, controlling ion diffusion and migration is challenging in nanoscale lattices. In this work, we intentionally insert a CdZnS alloyed interface layer, with small cationic size mismatch with Mn(ii) dopant ions, as an "atomic trap" to facilitate directional (outward and inward) dopant migration inside core/multi-shell quantum dots (QDs) to reduce the strain from the larger cationic mismatch between dopants and host sites.

Numerical Study of Metachronal Wave-Modulated Locomotion in Magnetic Cilia Carpets.

Metachronal motions are ubiquitous in terrestrial and aquatic organisms and have attracted substantial attention in engineering for their potential applications. Hard-magnetic soft materials are shown to provide new opportunities for metachronal wave-modulated robotic locomotion by multi-agent active morphing in response to external magnetic fields. However, the design and optimization of such magnetic soft robots can be complex, and the fabrication and magnetization processes are often delicate and time-consuming.

A Pliocene Precipitation Isotope Proxy-Model Comparison Assessing the Hydrological Fingerprints of Sea Surface Temperature Gradients.

The Pliocene offers insights into future climate, with near-modern atmospheric pCO and global mean surface temperature estimated to be 3-4°C above pre-industrial. However, the hydrological response differs between future global warming and early Pliocene climate model simulations. This discrepancy results from the use of reduced meridional and zonal sea surface temperature (SST) gradients, based on foraminiferal Mg/Ca and Alkenone proxy evidence, to force the early Pliocene simulation.

How cells wrap around virus-like particles using extracellular filamentous protein structures.

Nanoparticles, such as viruses, can enter cells via endocytosis. During endocytosis, the cell surface wraps around the nanoparticle to effectively eat it. Prior focus has been on how nanoparticle size and shape impacts endocytosis.

How cells wrap around virus-like particles using extracellular filamentous protein structures.

Nanoparticles, such as viruses, can enter cells via endocytosis. During endocytosis, the cell surface wraps around the nanoparticle to effectively eat it. Prior focus has been on how nanoparticle size and shape impacts endocytosis.

Data-driven analysis and predictive modeling on COVID-19.

The coronavirus (COVID-19) started in China in 2019, has spread rapidly in every single country and has spread in millions of cases worldwide. This paper presents a proposed approach that involves identifying the relative impact of COVID-19 on a specific gender, the mortality rate in specific age, investigating different safety measures adopted by each country and their impact on the virus growth rate. Our study proposes data-driven analysis and prediction modeling by investigating three aspects of the pandemic (gender of patients, global growth rate, and social distancing).

Cities in a pandemic: Evidence from China.

This paper studies the impact of urban density, city government efficiency, and medical resources on COVID-19 infection and death outcomes in China. We adopt a simultaneous spatial dynamic panel data model to account for (i) the simultaneity of infection and death outcomes, (ii) the spatial pattern of the transmission, (iii) the intertemporal dynamics of the disease, and (iv) the unobserved city-specific and time-specific effects. We find that, while population density increases the level of infections, government efficiency significantly mitigates the negative impact of urban density.

Terminal repeats impact collagen triple-helix stability through hydrogen bonding.

Nearly 30% of human proteins have tandem repeating sequences. Structural understanding of the terminal repeats is well-established for many repeat proteins with the common α-helix and β-sheet foldings. By contrast, the sequence-structure interplay of the terminal repeats of the collagen triple-helix remains to be fully explored.

A low cost, low power sap flux device for distributed and intensive monitoring of tree transpiration.

Accurate estimation of transpiration in individual trees is important for understanding plant responses to environmental drivers, closing the water balance in forest stands and catchments, and calibrating earth system models, among other applications. However, the cost and power consumption of commercial systems based on sap flow methods still limit their usage. We developed and tested a cost-effective (<$150), simple to construct, and energy efficient sap flux device based on the heat pulse method.

Photocatalytic turnover of CO under visible light by [Re(CO)(1-(1,10) phenanthroline-5-(4-nitro-naphthalimide))Cl] in tandem with the sacrificial donor BIH.

Optimized photocatalytic conversion of CO requires new potent catalysts that can absorb visible light. The photocatalytic reduction of CO using rhenium(i) has been demonstrated but suffers from low turnover. Herein, we describe a [Re(CO)(1-(1,10)phenanthroline-5-(4-nitro-naphthalimide))Cl] photocatalyst, which when combined with the sacrificial donor 1,3-dimethyl-2-phenyl-2,3-dihydro-1-benzo[]imidazole, results in selective production of formic acid and a high turnover number of 533 and turnover frequency of 356 h.

External validation of a pediatric decision rule for blunt abdominal trauma.

Introduction: Blunt traumatic injuries are a leading cause of morbidity and mortality in the pediatric population. Contrast-enhanced multidetector computed tomography is the best imaging tool for screening patients at risk of blunt abdominal injury. The Pediatric Emergency Care Applied Research Network (PECARN) abdominal rule was derived to identify patients at low risk for significant abdominal injury who do not require imaging.

Experimental evolution reveals sex-specific dominance for surviving bacterial infection in laboratory populations of .

Males and females are subjected to distinct kinds of selection pressures, often leading to the evolution of sex-specific genetic architecture, an example being sex-specific dominance. Sex-specific dominance reversals (SSDRs), where alleles at sexually antagonistic loci are at least partially dominant in the sex they benefit, have been documented in Atlantic salmon, rainbow trout, and seed beetles. Another interesting feature of many sexually reproducing organisms is the asymmetric inheritance pattern of X chromosomes, which often leads to distinct evolutionary outcomes on X chromosomes compared to autosomes.

Engineering reversible cell-cell interactions using enzymatically lipidated chemically self-assembled nanorings.

Multicellular biology is dependent on the control of cell-cell interactions. These concepts have begun to be exploited for engineering of cell-based therapies. Herein, we detail the use of a multivalent lipidated scaffold for the rapid and reversible manipulation of cell-cell interactions.

Lessons learned through listening to biology students during a transition to online learning in the wake of the COVID-19 pandemic.

During the Spring Semester of 2020, an outbreak of a novel coronavirus (SARS-CoV-2) and the illnesses it caused (COVID-19) led to widespread cancelling of on-campus instruction at colleges and universities in the United States and other countries around the world. Response to the pandemic in university settings included a rapid and unexpected shift to online learning for faculty and students. The transition to teaching and learning online posed many challenges, and the experiences of students during this crisis may inform future planning for distance learning experiences during the ongoing pandemic and beyond.

Intergenerational effects of childhood maltreatment: The roles of parents' emotion regulation and mentalization.

Background: Children living with parents who have childhood maltreatment histories tend to develop compromised behavioral health outcomes, suggesting the intergenerational effects of child maltreatment.

Objective: Driven by attachment theory, this study aims to identify the pathways from parents' childhood maltreatment to their child's behavioral problems and functioning.

Participants And Setting: The sample of parent participants (N = 202) was recruited from an online data collection platform - Amazon Mechanical Turk.

What is essential?: Understanding community resilience and public libraries in the United States during disasters.

Hurricane Katrina, the 4/27/2011 Tornadoes, the Oso Mudslide, and even more recently, the Coronavirus Pandemic, all demonstrated the devastating experience of disaster. While each of these extreme events varied in scope, size, and degree of disruption, each overwhelmed local authorities necessitating state and federal assistance. Prevention of disasters is ideal, but not practical.

How female × male and male × male interactions influence competitive fertilization in .

How males and females contribute to joint reproductive success has been a long-standing question in sexual selection. Under postcopulatory sexual selection, paternity success is predicted to derive from complex interactions among females engaging in cryptic female choice and males engaging in sperm competition. Such interactions have been identified as potential sources of genetic variation in sexually selected traits but are also expected to inhibit trait diversification.

Overexpression of induces salicylic acid-dependent defense against through the regulation of its targets .

microRNAs are powerful regulators of growth, development, and stress responses in plants. The microRNA was previously found to regulate diverse processes including flower development, root development, and response to osmotic stress by controlling the patterns of expression of its target genes and . Here, we report that also modulates defense against pathogens through and .

Increased cardiovascular events and mortality in females with NAFLD: a meta-analysis.

Non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVD) share similar risk factors. Recent studies have focused on obesity and insulin resistance, but the link between NAFLD and CVD persists regardless of traditional risk factors. Despite the increased incidence and prevalence of NAFLD worldwide, there has been no thorough investigation of gender disparities nor a closer look taken into investigating the role gender may play in increased cardiovascular (CV) mortality in people with NAFLD.

Episodic herbivory, plant density dependence, and stimulation of aboveground plant production.

Herbivory is a major energy transfer within ecosystems; an open question is under what circumstances it can stimulate aboveground seasonal primary production. Despite multiple field demonstrations, past theory considered herbivory as a continuous process and found stimulation of seasonal production to be unlikely. Here, we report a new theoretical model that explores the consequences of discrete herbivory events, or episodes, separated in time.

Communicating the consensus on climate change to college biology majors: The importance of preaching to the choir.

College and university biology majors who are not climate change deniers may yet be unaware of the degree of scientific consensus on climate change and unprepared to communicate about climate science to others. This study reports on a population of climate change accepting biology majors at a large, private research university in the American northeast. Our students tended to greatly underestimate the degree of scientific consensus around climate change, to be only moderately worried about climate change, and to be unconfident in their ability to communicate about the state of the scientific consensus around climate change.