Greater Density Research Articles

Targeted protein evolution in the gut microbiome by diversity-generating retroelements.

Diversity-generating retroelements (DGRs) accelerate evolution by rapidly diversifying variable proteins. The human gastrointestinal microbiota harbors the greatest density of DGRs known in nature, suggesting they play adaptive roles in this environment. We identified >1,100 unique DGRs among human-associated Bacteroides species and discovered a subset that diversify adhesive components of Type V pili and related proteins. We show that Bacteroides DGRs are horizontally transferred across species, that some are highly active while others are tightly controlled, and that they preferentially alter the functional characteristics of ligand-binding residues on adhesive organelles. Specific variable protein sequences are enriched when Bacteroides strains compete with other commensal bacteria in gnotobiotic mice. Analysis of >2,700 DGRs from diverse phyla in mother-infant pairs shows that Bacteroides DGRs are preferentially transferred to vaginally delivered infants where they actively diversify. Our observations provide a foundation for understanding the roles of stochastic, targeted genome plasticity in shaping host-associated microbial communities.

Sustainable concrete production: Partial aggregate replacement with electric arc furnace slag

Abstract The pursuit of sustainability in the construction industry has stimulated interest in seeking environmentally friendly alternatives to natural aggregates in concrete production. This study evaluates the behavior of concrete when electric arc furnace (EAF) slag is used as aggregates in its production. The primary research gap filled by this study is to deduce the blend of the fine and coarse EAF slag aggregates that would produce concrete of comparative strengths to concrete made with natural aggregates. Concrete mixtures were formulated using varied EAF slag content in the proportions of 0, 10, 15, 25, and 50%, respectively. The compressive strength values increased as the EAF slag content increased. However, this trend was not evident for the density and tensile strength values. The concrete mixture containing 25% EAF slag with 15% fine and 20% coarse EAF slag aggregates had the greatest density value of 2550.00 kg/m3 and the tensile strength value of 4.8 Pa respectively. This could be due to the distribution of the fine and coarse aggregate grains in the mixture. Since the percentage of fine and coarse aggregate grains were 10 and 15%, respectively, it was a close enough range for the fines to fill in the void spaces. This made the mixture more compact which resulted in a higher density and tensile strength values.

Wells‐Dawson Polyoxometalate Modified Lignin Derived High Surface Area Activated Carbon Electrode Materials for Energy Storage Application

AbstractSupercapacitors have emerged as a potential technology in the search for energy storage solutions, delivering astounding performance, environmental sustainability, safety, and economic feasibility. Biomass‐derived activated carbon electrodes have received much interest in this area because of their inherent mechanical stability and eco‐friendliness. While Wells‐Dawson POMs exhibit excellent redox properties for electrochemical performance, however, their solubility nature leads to poor conductivity. Biomass‐derived activated carbon was employed as a solid support material to address this issue, which offers high surface area and cost‐effectiveness. This work explores the synthesis of new nanofabricated electrodes by adding vanadium‐substituted Wells‐Dawson polyoxometalates (P2VW17) to activated carbon derived from lignin (LDAC). In depth, we investigated these novel nanohybrid material's structural properties and electrochemical performance. Furthermore, electrochemical testing was performed for 20 wt % LDAC‐P2VW17 in a 0.25 M H2SO4 electrolyte. The 20 wt % LDAC‐P2VW17 supercapacitor cell has an excellent specific capacitance of 216.48 F g−1, with great energy and power densities of 30.06 Wh kg−1 and 1999.98 W kg−1. Additionally, it has an excellent capacitance retention of 94.4 % over 4000 cycles with 82.6 % columbic efficiency. A test for practical application has been conducted on 20 wt % LDAC‐P2VW17. The first series of LEDs were connected to the workstation and took hold of 30 seconds to discharge. A piezoelectric buzzer was subjected to a trial as part of our testing procedure. Upon integration with our system, the buzzer produced an audible tone that persisted for 140 seconds.

Canadian Medical Imaging Inventory 2022–2023: SPECT and SPECT-CT

SPECT is a nuclear imaging technique that provides 3D information on functional and molecular processes in the body. SPECT has been integrated with CT to combine the imaging strengths of both modalities in SPECT-CT. In total, 331 SPECT-CT units in 10 provinces and 210 SPECT units operating in 9 provinces were identified by the Canadian Medical Imaging Inventory (CMII) in its 2022–2023 national survey. There are no SPECT-CT and SPECT units operating in Yukon, Northwest Territories, and Nunavut. Canada has 8.3 SPECT-CT units per million people and 5.3 SPECT units per million people. The greatest density of units per million people for SPECT-CT is in Newfoundland and Labrador and the greatest density for SPECT are in Alberta and New Brunswick. The combined volume of SPECT-CT and SPECT exams conducted in 2022–2023 has decreased by approximately 37.5% since 2015, which is attributed to the gradual decommissioning of SPECT units and replacement of these technologies with other imaging modalities. SPECT-CT is primarily used for oncology exams, followed by cardiology exams and musculoskeletal exams. SPECT is primarily used for cardiology exams, followed by oncology and musculoskeletal exams. On average, SPECT-CT and SPECT units operate approximately 42 hours per week across jurisdictions in Canada that have capacity.

Canadian Medical Imaging Inventory 2022–2023: CT

CT is an imaging technique that uses X-rays, sensitive radiation detectors, and computer analysis to produce cross-sectional images to detect abnormalities in areas of the body. CT was reported to have the largest demand in oncology (24%), followed by neurology (16.5%) and hepatobiliary (14%) use. Applications for CT continue to expand to new clinical indications and therapeutic areas. Five hundred and sixty CT units were identified by the CMII in its 2022–2023 national survey, with all provinces and territories reporting CT capacity. Most sites are publicly funded hospitals located in urban settings. Canada has an average of 14 CT units per million people. The greatest density of units per million people is in Newfoundland and Labrador, New Brunswick, Yukon, Northwest Territories and Nunavut. Canada is positioned in the bottom 15% of OECD countries in units per million population and the top 45% of OECD countries for average volume of publicly funded CT exams per1,000 population. Approximately 6.4 million publicly funded CT examinations were performed in the 2022–2023 fiscal year. This represents a national average of 160.2 exams per 1,000 people, an increase of 9% since 2015. The average age of CT equipment in Canada is 8.2 years; 29.8% of CT units are 5 years old or newer, 36.7% are 6 to 10 years old, and 33.4% are more than 10 years old. The adoption and use of radiation safety strategies are increasing in Canada. An increasing number of CT units are now equipped with dose-management controls and patient dose recording features. Approximately 30% of CT units are reported to have dual-target imaging. CT units operate an average of 14 hours per day. Approximately 80% of sites reported CT operation on weekends and 40% of sites reported CT operation 24 hours a day.

Canadian Medical Imaging Inventory 2022–2023: MRI

MRI is a noninvasive imaging modality that uses powerful electromagnetic and radiofrequency fields to produce cross-sectional images of the body. MRI is primarily used for neurologic exams (28%), followed by musculoskeletal (23%) and oncology exams (17%). In total, 432 MRI units in 11 jurisdictions were identified by the Canadian Medical Imaging Inventory (CMII) in its 2022 to 2023 national survey. Most sites are publicly funded hospitals located in urban centres. Canada has an average of 10.8 MRI units per million people. The greatest density of units per million people is in Yukon, Quebec, and New Brunswick. Overall, 2,214,157 publicly funded MRI examinations were performed in the 2022–2023 fiscal year. This represents a national average of 55.6 exams per 1,000 people, an increase of 4.3% since 2019– Canada is positioned in the bottom 25% of Organisation for Economic Co-operation and Development (OECD) countries in units per million population and the bottom 50% of OECD countries for average volume of publicly funded MRI exams per 1,000 population. The average age of MRI equipment in Canada is 8.4 years; 62.8% of MRI units are 10 years old or newer, 23.3% are 11 to 15 years old, and 13.9% are more than 15 years old. On average, MRI units operate 15.3 hours per day and 97.4 hours per week. Overall, 76.0% of sites reported MRI operation on weekends and 17% of sites reported operating 24 hours a day.

Canadian Medical Imaging Inventory 2022–2023: PET-CT and PET-MRI

PET-CT Imaging PET-CT is an advanced imaging technique that combines PET with CT to measure metabolic or biochemical activity in the human body. Sixty PET-CT units in 9 provinces were identified by the Canadian Medical Imaging Inventory (CMII) in its 2022–2023 national survey. All units are located in urban centres. Canada has 1.5 PET-CT units per million people. The greatest density of units per million people is in Quebec, New Brunswick, and Newfoundland and Labrador. Approximately 156,320 publicly funded PET-CT examinations were performed in the 2022–2023 fiscal year. This represents a national average of 3.9 exams per 1,000 people, an increase of 18.2% since 2019– PET-CT was reported to have the largest demand in oncology (66.1%), followed by cardiology (13.2%) and neurology (10.1%). Applications for PET-CT continue to expand to new clinical indications and therapeutic areas. The upfront capital and ongoing operational costs of PET-CT units, as well as the costs of radiopharmaceutical products and equipment, may act as barriers to the rapid adoption of this technology. Canada is positioned in the bottom 25% of Organisation for Economic Co-operation and Development (OECD) countries in units per million population and the bottom 50% of OECD countries for average volume of publicly funded PET-CT exams per 1,000 population. The average age of PET-CT equipment in Canada is 7.2 years; 51.5% of PET-CT units are 5 years old or newer, 21.2% are 6 to 10 years old, and 27.3% are more than 10 years old. Radiotracers are essential in PET imaging. The most commonly used PET-CT radiotracers are for oncology: 91% of sites reported using fluorodeoxyglucose F18 and 31.8% of sites reported using gallium-68 DOTA-TATE. The production of most radiotracers requires the use of a cyclotron.1 Overall, 21.7% of PET-CT sites reported local proximity to a cyclotron, reflecting a disparity in the access to and growing demand for radiotracer supply. PET-MRI Imaging PET-MRI is a technique that combines PET with MRI to produce highly detailed imaging of soft tissues in the human body. PET-MRI is almost exclusively used for research purposes in Canada; therefore, data are limited for this modality. Six PET-MRI units were identified in Canada across 3 provinces, representing a national average of 0.2 units per million people. The average age of PET-MRI equipment in Canada is 6.7 years; 2 units are 6 to 10 years old, and 1 unit is 5 years old.

Genome scans for selection signatures identify candidate virulence genes for adaptation of the soybean cyst nematode to host resistance.

Plant pathogens are constantly under selection pressure for host resistance adaptation. Soybean cyst nematode (SCN, Heterodera glycines) is a major pest of soybean primarily managed through resistant cultivars; however, SCN populations have evolved virulence in response to selection pressures driven by repeated monoculture of the same genetic resistance. Resistance to SCN is mediated by multiple epistatic interactions between Rhg (for resistance to H. glycines) genes. However, the identity of SCN virulence genes that confer the ability to overcome resistance remains unknown. To identify candidate genomic regions showing signatures of selection for increased virulence, we conducted whole genome resequencing of pooled individuals (Pool-Seq) from two pairs of SCN populations adapted on soybeans with Peking-type (rhg1-a, rhg2, and Rhg4) resistance. Population differentiation and principal component analysis-based approaches identified approximately 0.72-0.79 million SNPs, the frequency of which showed potential selection signatures across multiple genomic regions. Chromosomes 3 and 6 between population pairs showed the greatest density of outlier SNPs with high population differentiation. Conducting multiple outlier detection tests to identify overlapping SNPs resulted in a total of 966 significantly differentiated SNPs, of which 285 exon SNPs were mapped to 97 genes. Of these, six genes encoded members of known stylet-secreted effector protein families potentially involved in host defence modulation including venom-allergen-like, annexin, glutathione synthetase, SPRYSEC, chitinase, and CLE effector proteins. Further functional analysis of identified candidate genes will provide new insights into the genetic mechanisms by which SCN overcomes soybean resistance and inform the development of molecular markers for rapidly screening the virulence profile of an SCN-infested field.

Jaguar conservation is caught in the crossfire of America's 'War on Drugs'

International conservation efforts and prohibitionary drug intersect in unexpected ways throughout the Mesoamerican Biological Corridor (MBC). US-led counterdrug interdiction of transnational cocaine trafficking, or ‘narco-trafficking’, is increasingly pushing narco-traffickers and their associated environmental destruction into protected areas (PAs) to establish new smuggling routes. These locations are also where the greatest densities of jaguars (Panthera onca), an iconic and declining species, are found in Central America. Intersecting two geospatial datasets estimating 1) jaguar densities and 2) changes in landscape suitability for drug trafficking following counterdrug interdiction pressure, we estimated that roughly 69 % of the estimated population of jaguars in the MBC were found in areas of increased suitability for narco-traffickers. Moreover, jaguar populations within PAs were 2.5 and 34 times more likely to be in increased narco-trafficking suitability areas than those in jaguar corridors or other area without conservation designations, respectively. These findings illustrate the full costs of continuing current counterdrug interdiction policies alongside conventional conservation strategies and suggest that community-based conservation governance may more effectively discourage narco-trafficking activities and enhance conservation outcomes.

Disparities in Multiple Myeloma Mortality Rate Trends by Demographic Status in the USA.

Multiple myeloma (MM) is a hematological malignancy that arises when plasma cells undergo malignant monoclonal proliferation. This study aimed to assess the demographic disparities and temporal trends in the mortality rates of this disease. We employed the Center for Disease Control and Prevention's Wide-ranging ONline Data for Epidemiologic Research (CDC WONDER) database. We found that for the overall U.S. population, the age-adjusted mortality rate per 1,000,000 (AAMR) decreased from 1999 to 2020. However, rates differed between demographic groups. In addition, we sought to find a significant average annual percent change (AAPC) in mortality rate from 1999 to 2020 for various demographic populations and compared groups to find disparities in mortality rate trend. In 2020, the AAMR due to MM was 38.0 and for women 24.1. The AAPC in AAMR from 1999 to 2020 in men was -1.0% (95%CI=-1.3 to -0.7) and in women was -1.6% (95%CI=-1.6 to -2.3). A significant difference in trend by sex was found, where women had a higher rate of decline. In 2020, the AAMR for the American Indian or Alaska Native (AI/AN) population was 15.0, the Asian American and Pacific Islander (AAPI) had 14.8, the Black and African American population had an AAMR of 55.6 and the White population had an AAMR of 28.1. The AAPC for the AI/AN population was -2.2% (95%CI=-3.5 to -0.9), for the AAPI population it was -0.9% (95%CI=-1.5 to -0.4), the Black and African American population had -1.5% (95%CI=-2.2 to -0.8) and the AAPC for the White population was -1.1% (95%CI=-1.6 to -0.6). A significant difference in trend of decline was found between the AAPI and Black and African American populations and between the AI/AN and Black and African American populations. When assessing the U.S. by states, the mid-southeast U.S. had the greatest density of the states with high AAMRs. These findings suggest which populations are at increased risk for mortality due to multiple myeloma and where we should apply additional resources and research.

Distribution of interstitial cells within the mouse esophagus and their spatial relationship to enteric neurons

Background/Objectives: The esophagus is a conduit for the passage of ingested material into the stomach. In humans, it is divided into thirds; the proximal portion is composed of skeletal muscle, the distal is composed of smooth muscle and the middle is a transition zone between skeletal and smooth muscles. In other species such as the mouse, the esophagus has been described to consist entirely of skeletal muscle. Despite this, interstitial cells of Cajal (ICC), cells that regulate gastrointestinal (GI) smooth muscle contractility, have been identified throughout the mouse esophageal body (Rumessen et al., 2001; PMID:11683170). Additional studies in the human esophagus have identified another interstitial cell type, PDGFRa+ cells (Chen et al., 2013; PMID:23734090). However, the distribution of interstitial cells, motor and sensory neurons and their spatial relationship to one another have never been examined. Since interstitial cells modulate contractility of smooth muscle in other GI regions, the presence of these cells leads to the hypothesis that the mouse esophagus also contains smooth muscle cells (SMCs). Therefore, the aims of our study were to 1) determine if SMCs are found within the mouse esophagus, 2) characterize the distribution of ICC and PDGFRa+ cells, and 3) examine the relationship of interstitial cells to enteric motor and sensory neurons. Methods: Wildtype (C57Bl/6) and smooth muscle eGFP (smMHC-eGFP) mouse esophagus was used for dual labeling immunohistochemistry. ICC were labeled with antibodies against Kit or ANO1. PDGFRa+ cells were labeled with antibodies against PDGFRa or SK3. Extrinsic sympathetic neurons were labeled with tyrosine hydroxylase (TH). Motor neurons were labeled with antibodies against NOS, VIP (inhibitory) and vChAT (excitatory). Sensory neurons were labeled with CGRP. Images were taken with a Leica Stellaris 5 confocal microscope and processed using LasX software. Results: SMCs were found throughout the length of the esophagus, although their density declined proximally. Intramuscular ICC expressed ANO1 and were distributed throughout the length of the esophagus with the greatest density in the gastroesophageal junction (GEJ). Submucosal and intramuscular PDGFRa+ cells were distributed throughout the esophagus and GEJ. Intramuscular PDGFRa+ cells expressed SK3 though this expression declined proximally. SMCs, intramuscular ICC and PDGFRa+ cells were closely associated with one another as well as with neurons. Discussion/Conclusions: This study is the first to systematically characterize SMCs, ICC, PDGFRa+ cells and neurons in the mouse esophagus. These findings suggest that the mouse may represent a better translational model for studying esophageal motility than previously assumed. NIH DK129528 and P20GM130459. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Diversity of bivalve and gastropod species in mangrove restoration areas

Bivalvia and gastropods are two types of mollusks found in mangrove habitats. This group of mollusks performs a vital function in their environment, including serving as a biofilter and decomposing organic waste. The abundance of bivalves and gastropods in their natural environment is presumed to have been impacted by deforestation and restoration processes in mangrove ecosystems. Therefore, this study was conducted to collect information about the composition and variety of bivalves and gastropods in the mangrove restoration area of Bagan Serdang village in North Sumatra. This research was conducted using the plot method with a plot size of 2m x 2m. Observation plots are created along specified paths with alternate placements. According to the findings, up to 19 types of mollusks were discovered at the study site. This investigation discovered 14 snail species and 10 gastropod families. The other five species are Bivalvia from four different families. M. strigata has the greatest density of 0.26 and the highest relative density of 3.90%. At the study site, the bivalve and gastropod diversity index was moderate (2.127), the evenness index was high (0.722), and the dominance index was low (0.211). It is highly recommended to continue to promote vegetation species at the study location in order to improve bivalves and gastropod species and numbers.

Sustainable development of three distinct starch based bio-composites reinforced with the cotton spinning waste collected from fiber preparation stage

Composites are new materials that combine two or more distinct components with diverse properties to create a new material with improved properties. The goal of this endeavor was to use fiber preparation wastes, or waste from cotton spinning mill blow room and carding, to produce bio composites based on starch. The matrix was prepared using the starches of potatoes, maize, and arrowroot, and any remaining reinforcing material was used. A hand layup technique was used to make the bio-composites. Tensile, bending, density, water absorbency, and SEM testing were among the studies used to illustrate the starch-based biodegradable materials. The maximum tensile strength of 0.49 MPa is displayed by sample AB. The resistive bending force of 3.71 MPa is greatest in Sample AB. The most uniform combination of reinforcing material (wastage cotton) and matrix is seen in PB's SEM picture. Among the samples, AB had the greatest density value, measuring 0.35 g/cm3. The sample PC had the highest absorption findings in both water and the 5 % HCl combination because carding waste had more fiber than blow room and fiber absorbs more water. The resultant bio-composites made of starch had the potential to replace Styrofoam.

What Is in the Bank? Assessing Persistent Soil Seed Bank Density of Sclerocactus wrightiae (Cactaceae)

Wright fishhook cactus is a small globose cactus endemic to an area of 280,000 ha in south-central Utah and was listed as endangered in October of 1979 by the U.S. Fish and Wildlife Service (USFWS). There is a general paucity of information about this species, and no published data on the seed bank for any species in the genus. Our objective with this study was to provide insight into the established seed bank density for this species. We processed 500 soil samples from various locations near individual cacti and potential neighboring nurse plants. We found that the species had a detectable seed bank of a size similar to other members of the Cactaceae family. Seed bank densities were the highest immediately adjacent to, and downslope from, parent plants. Our data indicate that areas within 20 cm of seed-producing cacti contain by far the greatest density of seeds. These areas should be given special consideration in future management plans for this species.

Ventilation shutdown and the breath-taking violence of infectious disease emergency management in industrial livestock production

Powerful ventilation systems are a crucial technology in industrial livestock production, mitigating the unhealthy ambient conditions that result from great densities of animal bodies, biowastes, and chemical agents, and enabling the rapid production of massive quantities of flesh and eggs in such crowded indoor spaces. But bad air is just one of many biophysical and technoscientific challenges managed in these spaces, chief among them the ever-present risks of infectious disease transmission and evolution that threaten animal health and productivity and pose untold risks for humans. This article examines the intersection of these two central problems, where ventilation systems that are normally used to manage bad air within enclosures have been repurposed in the context of disease outbreaks to quickly and cheaply kill infected populations by hyperthermia. An analysis of this nascent practice, euphemistically termed “ventilation shutdown,” shows how governments and publicly funded scientific institutions have worked with private industry to develop and systematize the use of this and other technologies of mass death to respond to infectious disease emergencies, a dynamic that, we argue, sheds new light on both the precarity and the violence of industrial livestock production.

The 2022 Starlink Geomagnetic Storms: Global Thermospheric Response to a High‐Latitude Ionospheric Driver

AbstractIn this study, we present ionospheric observations of field‐aligned currents from AMPERE and the ESA Swarm A satellite, in conjunction with high‐resolution thermospheric density measurements from accelerometers on board Swarm C and GRACE‐FO, for the third and 4 February 2022 geomagnetic storms that led to the loss of 38 Starlink internet satellites. We study the global storm time response of the thermospheric density enhancements, including their decay and latitudinal distribution. We find that the thermospheric density enhances globally in response to high‐latitude energy input from the magnetosphere‐solar wind system and takes at least a full day to recover to pre‐storm density levels. We also find that the greatest density perturbations occur at polar latitudes consistent with the magnetosphere‐ionosphere dayside cusp, and that there appeared to be a saturation of the thermospheric density during the geomagnetic storm on the fourth. Our results highlight the critical importance of high‐latitude ionospheric observations when diagnosing potentially hazardous conditions for low‐Earth‐orbit satellites.

Effect of TiO2 on the Microstructure and Flexural Strength of Lunar Regolith Simulant

Lunar regolith is the preferred material for lunar base construction using in situ resource utilization technology. The TiO2 variations in lunar regolith collected from different locations significantly impact its suitability as a construction material. Therefore, it is crucial to investigate the effects of TiO2 on the properties of lunar regolith. This study aims to evaluate the influence of TiO2 content and sintering temperature on phase transformation, microstructure, and macroscopic properties (e.g., the shrinkage rate, mechanical properties, and relative density) of lunar regolith simulant samples (CUG-1A). The flexural strength and relative density of the sample with a TiO2 content of 6 wt% sintered at 1100 °C reached 136.66 ± 4.92 MPa and 91.06%, which were 65% and 12.28% higher than those of the sample not doped with TiO2, respectively. The experiment demonstrated that the doped TiO2 not only reacted with Fe to form pseudobrookite (Fe2TiO5) but also effectively reduced the viscosity of the glass phase during heat treatment. As the sintering temperature increased, the particles underwent a gradual melting process, leading to a higher proportion of the liquid phase. The higher liquid-phase content had a positive impact on the diffusion of mass transfer, causing the voids and gaps between particles to shrink. This shrinkage resulted in greater density and, ultimately, improved the mechanical properties of the material.

Ultrasonic activation of the endodontic sealer enhances its intratubular penetration and bond strength to irradiated root dentin.

To evaluate the effect of ultrasonic activation of the endodontic sealer on its intratubular penetration and bond strength to irradiated root dentin. Forty human teeth were distributed into 4 groups (n = 10), according to the radiation therapy (RT) exposure-70Gy-and ultrasonic activation (UA) of the endodontic sealer: RT/UA-irradiated teeth and sealer UA; RT/no-UA-irradiated teeth and no sealer UA; no-RT/UA-non-irradiated teeth and sealer UA and no-RT/no-UA-non-irradiated teeth and no sealer UA. Push-out bond strength test was performed in a Universal Testing Machine. Failure modes and adhesive interface were analyzed under Scanning Electron Microscopy. The data were statistically compared (two-way-ANOVA and posthoc Games-Howell test; Fisher's exact test -α = 5%). The different experimental conditions (radiation and UA) and the root third had a significant effect on push-out bond strength, and the interaction of these factors was significant (p < 0.05). UA of the sealer significantly increased its bond strength to both irradiated and non-irradiated dentin (p < 0.05). The irradiated groups mostly presented adhesive-type failure of the sealer (p < 0.01). Regardless of the irradiation, the ultrasonically activated groups showed a more homogeneous adhesive interface, with the presence of sealer tags in greater density and depth. Ultrasonic activation enhanced the intratubular penetration and the bond strength of the endodontic sealer to irradiated dentin. The impact of ultrasonic activation of the endodontic sealer on teeth undergoing radiotherapy is a gap in the scientific literature that needs to be bridged.

Novel insights into mechanisms of inhibition of colonic motility by loperamide.

It is well known that opiates slow gastrointestinal (GI) transit, via suppression of enteric cholinergic neurotransmission throughout the GI tract, particularly the large intestine where constipation is commonly induced. It is not clear whether there is uniform suppression of enteric neurotransmission and colonic motility across the full length of the colon. Here, we investigated whether regional changes in colonic motility occur using the peripherally-restricted mu opioid agonist, loperamide to inhibit colonic motor complexes (CMCs) in isolated mouse colon. High-resolution video imaging was performed to monitor colonic wall diameter on isolated whole mouse colon. Regional changes in the effects of loperamide on the pattern generator underlying cyclical CMCs and their propagation across the full length of large intestine were determined. The sensitivity of CMCs to loperamide across the length of colon varied significantly. Although there was a dose-dependent inhibition of CMCs with increasing concentrations of loperamide (10 nM - 1 μM), a major observation was that in the mid and distal colon, CMCs were abolished at low doses of loperamide (100 nM), while in the proximal colon, CMCs persisted at the same low concentration, albeit at a significantly slower frequency. Propagation velocity of CMCs was significantly reduced by 46%. The inhibitory effects of loperamide on CMCs were reversed by naloxone (1 μM). Naloxone alone did not change ongoing CMC characteristics. The results show pronounced differences in the inhibitory action of loperamide across the length of large intestine. The most potent effect of loperamide to retard colonic transit occurred between the proximal colon and mid/distal regions of colon. One of the possibilities as to why this occurs is because the greatest density of mu opioid receptors are located on interneurons responsible for neuro-neuronal transmission underlying CMCs propagation between the proximal and mid/distal colon. The absence of effect of naloxone alone on CMC characteristics suggest that the mu opioid receptor has little ongoing constitutive activity under our recording conditions.

Recent advancements in pesticide mitigation using engineered Escherichia coli strains

Pesticides have considerably increased agricultural output, but their overuse presents serious threats to human health, food safety, and the environment. Alarmingly, only around 1% of pesticides used reach their intended pests, with the remainder polluting soil, water, and air. This causes broad environmental contamination and negative consequences on non-target animals, including people. Top pesticide-consuming countries, including China, the United States, and Brazil, confront considerable issues due to residual pesticide buildup. Recent biotechnology developments provide intriguing pesticide mitigation strategies. Engineered Escherichia coli (E. coli) strains have developed as very efficient bioremediation agents. These genetically engineered microbes are intended to convert hazardous chemicals into harmless metabolites. E. coli strains are tailored for increased expression of pesticide-degrading genes using modern genetic and metabolic engineering, dramatically enhancing their ability to break down hazardous chemicals. Studies have shown that modified E. coli may degrade persistent pesticides such as Paraoxon and p-nitrophenol (PNP), turning them to harmless molecules. These bacteria may reach great densities, making them ideal for large-scale detoxifying operations. Furthermore, recombinant DNA technology enables the development of E. coli strains with several copies of degradation genes, which improves their bioremediation capacities. Despite these advances, obstacles persist, including biosafety issues and the need for regulatory supervision. Ongoing research is critical for addressing these concerns and developing safer, more sustainable agriculture techniques. Engineered E. coli strains represent a substantial advancement in pesticide mitigation, providing a feasible approach for reducing environmental pollution and protecting human health.