Influence of dry-wet cycles and chemical pollution on red soil improved with building gypsum powder

Civil Engineering Sciences

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(A) Acetic acid contamination. (B) Sodium sulfate contamination. (C) Sodium hydroxide contamination.

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Credit: The Authors, Civil Engineering Sciences

Red soil exhibits a high susceptibility to geological disasters and engineering instability owing to its significant dispersibility and substantial strength attenuation upon exposure to water. Consequently, there is an urgent necessity to enhance its engineering properties. As an environmentally friendly and cost-effective industrial by-product, building gypsum powder demonstrates significant potential in improving the mechanical properties of red soil. It not only reduces the burden of landfilling and lowers material costs but also achieves efficient waste utilization and resource recycling, substantially cutting expenses related to soil stabilization and improvement. It is expected to provide a scientific basis for the analysis of geological hazards such as debris flows, landslides, and collapses in red soil regions, as well as offer guidance for selecting appropriate types and dosage of soil modifiers in practical engineering projects.

Recently, a team led by Yinlei Sun from Yunnan University in Yunnan Province, China, has investigated the impacts of wet-dry cycling and chemical contamination on the improvement of red soil using building gypsum powder, aiming to advance research in the field of red soil modification. Building gypsum powder, which is environmentally friendly, cost-effective, and exhibits remarkable modification effects, stands as an ideal choice for red soil amendment. Utilizing gypsum powder derived from demolished construction waste for soil improvement not only reduces the landfill burden and lowers material costs but also achieves efficient waste utilization and resource recycling. Current research endeavors are focused on revealing the intrinsic relationships between the shear strength, compressibility, and microstructure of both undisturbed and modified red soils, as well as delving into the macroscopic mechanical properties such as shear strength and compressibility of modified red soil and the underlying modification mechanisms. This holds significant importance for refining the macroscopic mechanical theory of red soil and addressing practical engineering application challenges.

The team published their review in Civil Engineering Sciences on 23 February 2026.

“In this study, we have outlined the efforts made by our research team in investigating the impact of dry-wet cycles and chemical contamination on red soil improved with building gypsum powder. This study focuses on the mechanical properties and microstructural evolution of the improved red soil under complex environmental conditions, systematically exploring the influence of acetic acid, sodium hydroxide, and sodium sulfate on the mechanical properties of building gypsum powder-improved red soil under dry-wet cycles, as well as their underlying mechanisms. The study found that when the improved red soil is exposed to various chemical contaminants, there are significant differences in its mechanical properties (including cohesion, internal friction angle, shear strength, and compressive strength)," said Professor Yin-Lei Sun from the School of Architecture and Planning at Yunnan University (the corresponding author of this study).

Building gypsum powder, known for its environmental friendliness, cost-effectiveness, and remarkable improvement effects, serves as an ideal modifier for red soil. Given the high susceptibility of red soil to geological disasters and engineering instability due to its significant dispersibility and substantial strength attenuation upon exposure to water, there is an urgent necessity to enhance its engineering properties. “The utilization of building gypsum powder not only improves the mechanical properties of red soil but also promotes resource utilization and waste recycling by employing gypsum waste from demolished buildings, thereby reducing landfill burdens and material costs,” Professor Yin-Lei Sun added.

The research team conducted a series of direct shear and consolidation tests on red soil specimens amended with building gypsum powder, combined with microscopic techniques such as SEM, XRD, and XRF, to analyze the mineral composition and microstructural alterations. “Our findings indicate that acetic acid leads to the dissolution of gypsum components, initiating pore development and substantially reducing soil strength. In contrast, sodium sulfate, at low concentrations, crystallizes to fill pores and augment strength, whereas high-concentration crystallization results in expansion and structural damage. Sodium hydroxide triggers the thickening of the double electric layer and colloid precipitation, thereby cementing the soil skeleton and mitigating the adverse effects of dry-wet cycles,” explained Zhen Li, the first author of this study.

The study also revealed that as the number of dry-wet cycles increased, soil pores expanded, the soil structure loosened, and both shear and compressive resistance diminished. “By utilizing gray correlation analysis and fractal theory, we established a quantitative relationship between microstructural parameters and disintegration, elucidating the predominant role of pore characteristics in determining macroscopic mechanical properties and the underlying mechanism of mineral component alterations,” stated Xian-Wei Zhang, a corresponding author from the State Key Laboratory of Geomechanics and Geotechnical Engineering at the Chinese Academy of Sciences.

The research team expects that this study will provide a theoretical foundation and strategic guidance for the prevention and control of red soil disasters, as well as the optimization of geotechnical reinforcement materials. “Looking ahead, we anticipate that the application of building gypsum powder in red soil improvement will become more widespread and practical. Future research will focus on optimizing the modifier dosage, exploring long-term performance under complex environmental conditions, and developing cost-effective and environmentally friendly improvement techniques,” Zhen Li concluded.

Other contributors to this study include Qing-Ru Du,Xuan-Chen Lin, and Jian-Bin Xie from the School of Architecture and Planning at Yunnan University.

This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 525608054, 42372313, and 12462033); the Natural Science Foundation of Yunnan Province, China (Grant No. 202401CF070174); the Open Research Fund of Key Laboratory of Flood and Drought Disaster Defense, Ministry of Water Resources (Grant No. wx20241100518); the Xingdian Talent Support Program (Grant No. C619300A130); and the Practical Innovation Project of Postgraduate Students in the Professional Degree of Yunnan University (Grant No. ZC-24249614).

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Journal

Civil Engineering Sciences

DOI

10.34133/cesci.0015 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Influence of Dry–Wet Cycles and Chemical Pollution on Red Soil Improved with Building Gypsum Powder

 

BU researchers identify bile acid and steroid signatures tied to extreme longevity

New study points to metabolic pathways that could potentially be targeted to prevent or treat age-related conditions.

Boston University School of Medicine

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(Boston)—Centenarians often live to 100+ due to a combination of protective genetic factors, which account for up to 50%, and healthy lifestyles, such as plant-forward diets, regular, natural movement and strong social connections. While these “agers” often possess unique immune system signatures, understanding the metabolic signs of healthy aging is not yet fully understood.

 

In a new study from Boston University Chobanian & Avedisian School of Medicine, researchers have discovered that centenarians have a distinct blood metabolite pattern that is not just an extension of normal aging. In particular, they show uniquely higher levels of certain primary and secondary bile acids and preserved levels of several steroids, patterns that diverge from the typical age trends seen in non-centenarians and that are linked to lower death risk.  

 

“Our study points to measurable chemical fingerprints in the blood that are associated with living a very long and healthy life. If we can understand those fingerprints, we may identify biological pathways that could contribute to protecting people from age-related decline,” explains corresponding author Stefano Monti, PhD, professor of medicine at the school.

 

The researchers collected blood samples from 213 people (70 centenarians, their children (offspring), and age-matched controls) from the New England Centenarian Study, one of the largest studies of long-lived individuals in North America led by Thomas Perls, MD, professor of medicine at the school. Using an untargeted metabolomics assay, they measured levels of approximately 1,495 small molecules in serum. They then compared metabolite levels between centenarians, offspring, and controls, and looked for metabolites that change with chronological age. They compared their results with four other metabolomics studies (some that included long-lived people and some that did not) to see which signals were consistent. They also checked which metabolites or groups of metabolites predicted how long people lived after the blood draw (survival analysis). Finally, they trained a machine-learning model “metabolomic clock”) to predict biological age from metabolite levels and tested whether being biologically younger or older than your calendar age relates to survival.

 

According to the researchers, the identified metabolites and patterns could become biomarkers to estimate someone’s biological age, to identify people at higher or lower risk of age-related decline, or to monitor responses to lifestyle or drug interventions aimed at improving health with age. They believe some specific pathways (bile acids, NAD-related pathways, gut bacterial metabolites, oxidative stress markers and certain steroids) warrant further investigation as potential targets for therapies or dietary interventions in the future.

 

“We hope this study helps point to measurable metabolic signs of healthy aging that can be tracked and targeted. However, the study's cross-sectional design means we cannot yet determine cause and effect, and these findings need validation in larger, diverse populations. Ultimately, our goal is to translate these insights into tests and safe interventions that help people stay healthier and more active for longer,” adds Monti.

 

These findings appear online in the journal GeroScience.

 

 

 

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Journal

GeroScience

DOI

10.1007/s11357-026-02174-2 

Method of Research

Experimental study

Subject of Research

Human tissue samples

Article Title

Metabolomic signatures of extreme old age: findings from the New England Centenarian Study

Article Publication Date

27-Mar-2026

 

Study: Intermittent fasting positively affects female hormones in PCOS 

University of Illinois Chicago

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Krista Varady 

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Credit: Photo: UIC

Polycystic ovary syndrome, or PCOS, affects as many as 18% of all childbearing-age women. The condition occurs when a woman’s body produces too much of a group of hormones called androgens, chiefly testosterone. Menstrual irregularity, obesity and even infertility can result.

The first line of treatment is typically hormonal birth control, said UIC professor of nutrition Krista Varady. But there can be negative side effects to mood, libido and metabolism, plus an increased stroke risk in some people, Varady said.

“We’re looking for other ways of lowering testosterone levels in these women,” she said. “One way is through weight loss. If someone loses around 5% of their body weight, they can actually help lower testosterone levels and sidestep any kind of drug intervention.”

A new study led by Varady tested how one weight-loss method — intermittent fasting — affects hormones and symptoms in patients with PCOS. Published in Nature Medicine, the research shows that restricting eating to a six-hour daily window decreased testosterone without negatively affecting female hormones. The study also showed that weight loss through calorie counting decreased testosterone. 

However, some critics of intermittent fasting have posited that the diet disrupts female hormones, Varady said.

“There’s a particular sentiment that intermittent fasting is really bad for women.” This is untrue, she said. “This study and several other studies published by our lab and others show that intermittent fasting can actually improve female hormone levels, particularly in women with PCOS.” 

Varady and her colleagues studied a type of intermittent fasting called time-restricted eating. In this method, you eat only during a set six- or eight-hour period each day. During the remaining 18 or 16 hours, you fast with calorie-free beverages and water until the next day. 

Simply put, the strategy helps people eat less, Varady said. So does counting calories, a method Varady and her colleagues tested alongside intermittent fasting in the study. But intermittent fasting had some additional benefits.

“It’s a way of reducing energy intake without having to do really complicated calorie counting,” she said about intermittent fasting. Varady and others have shown in previous work that eating only during an eight-hour window can cut around 300 to 500 calories a day.

In addition to obesity and insulin resistance, which raise risks of diabetes and heart disease, PCOS can cause ovarian cysts, acne and facial hair growth.

In a group of 76 pre-menopausal women with PCOS, the researchers tested how outcomes differed after six months between time-restricted eating between 1 and 7 p.m. daily and calorie counting. Both diet schemes ended up cutting participants’ intake by about 200 calories per day, the team found, leading to average weight loss of about 10 pounds over the six months.

Both groups also experienced a decrease in testosterone concentrations. But only time-restricted eating reduced free androgen index, the ratio between testosterone and the protein that transports it through the blood, which is a marker of how much active testosterone is reaching a body’s tissues. It also improved A1C levels, a risk marker for diabetes, Varady said.

Though intermittent fasting did not lessen other PCOS symptoms, like menstrual period irregularity, Varady suggested those symptoms might improve with longer time on the diet and greater weight loss.

About 80% of the participants in the time-restricted eating group said they were going to continue the diet, Varady said.

The study was a team effort among nutrition professors in the department of kinesiology and nutrition in the College of Applied Health Sciences. Sofia Cienfuegos designed and ran the study with Varady, while Kelsey Gabel, Lisa Tussing-Humphreys and Vanessa Oddo collaborated as well.

“We all have a keen interest in women’s health, and we designed this together and ran it together,” Varady said. “It was one of the biggest nutrition department collaborations we’ve ever done.”

Other UIC authors on the study include Sarah Corapi, Mary-Claire Runchey, Jodie Lyons, Maria Alonso de Leon, Vasiliki Pavlou and Mark Ezpeleta from the College of Applied Health Sciences; Julienne Sanchez from the College of Medicine; and Shuhao Lin, formerly of UIC and now with the Mayo Clinic. 

Story by Tess Joosse

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Journal

Nature Medicine

 

Mizzou team discovers what makes all-female fish species a scientific ‘miracle’

Amazon molly fish reproduce asexually yet somehow avoid the genetic mutations that could lead to extinction. Researchers are discovering why.

University of Missouri-Columbia

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Wes Warren

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Credit: University of Missouri

University of Missouri researchers have shown how an all-female fish species called the Amazon molly defies the long-held belief that asexual reproduction is an evolutionary dead end.

The key is gene conversion — a process in which one copy of a gene overwrites the other one. Using a technique known as long-read sequencing, Mizzou researchers Wes Warren and Edward Ricemeyer were able to document this process at the genetic level in the Amazon molly for the first time.

Animals that reproduce asexually by cloning themselves have genetic disadvantages. Harmful mutations are expected to accumulate over time, and limited genetic diversity can reduce their ability to adapt — often putting them on a fast track to extinction.

The Amazon molly shatters that assumption. It isn’t merely surviving; it’s thriving. Now, Mizzou researchers have uncovered the secret behind its evolutionary success.

A blast from the past

The Amazon molly fish first emerged over 100,000 years ago, born from a rare hybrid pairing between two different fish species: a male Poecilia latipinna fish and a female Poecilia mexicana fish. The hybrid has been cloning itself ever since. In 1932, the Amazon molly became the first vertebrate confirmed to be capable of asexual reproduction — a list that today includes about 100 species.

Even then, the discovery raised eyebrows. Prediction models suggested the species should not have survived beyond 10,000 years. So how is it still thriving genetically more than 100,000 years later?

Warren and Ricemeyer have spent more than a decade trying to find out.

In 2018, Warren — now a Curators’ Distinguished Professor in the College of Agriculture, Food and Natural Resources and School of Medicine — mapped out the Amazon molly’s full genome for the first time, expecting to find the genetic damage left behind by millennia of cloning. Instead, the DNA looked healthy, similar to what scientists would expect to see in a species that reproduces sexually.

Warren speculated that gene conversion was responsible. The process allowed the Amazon molly to preserve and repair DNA inherited from both original parent species, even after tens of thousands of years.

Until recently, however, there was no way to prove his theory.

That changed with the advent of long-read sequencing, which allowed Warren and Ricemeyer to accurately compare the DNA sequences from both of the Amazon molly’s parents to accurately measure how they have evolved. They found that the two genomes of the parents were mutating at different rates, with one side mutating faster than the other.

“This was shocking because it goes against everything scientists thought we understood about mutation rates,” Ricemeyer, a computational biologist, said. “Normally, mutations are based on what is happening externally to the fish, whether that is changes in environment or population size, so we assumed mutations from both genome sets are occurring at the same rate. To have two genomes be present inside the same cells of the same fish doing two very different things in terms of mutation rates was shocking. When we submitted our work to the journal, the reviewers didn’t believe us at first. They were just as surprised as we were, and asked us to provide much more evidence.”

Gene conversion seemed to be happening at an optimal rate. Too much gene conversion would limit genetic diversity while too little would allow bad mutations to accumulate. The good genes seemed to be spreading more while the bad genes were being weeded out over time — a process that normally only happens through sexual reproduction.

“If a genome is supposed to decay and it doesn’t, why?” Warren, a principal investigator in the Bond Life Sciences Center, said. “As curious researchers, we were excited to find out. This fish seems to have the best of both worlds — the genetic health that normally comes from sexual reproduction while not needing a male’s DNA to reproduce.”

How we got here

The research reshapes how scientists understand the evolutionary potential of asexual reproduction. While fish are ideal for laboratory study, the discovery could spark future work to see whether other animals that reproduce asexually, such as Komodo dragons and New Mexico whiptail lizards, rely on gene conversion in a similar way.

Advances in genome evolution research have already improved plant and animal breeding. They’ve helped scientists better understand the causes of genetic diseases, including how genes mutate and repair themselves — work that plays a critical role in cancer treatment.

“Better understanding the different ways that reproduction happens helps us better understand ourselves,” Ricemeyer said. “How we got here, and where we may be headed.”

The study, “Gene conversion empowers natural selection in a clonal fish species,” was published in Nature.

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Journal

Nature

DOI

10.1038/s41586-026-10180-9 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Gene conversion empowers natural selection in a clonal fish species

 

Houston Methodist research cracks genetic code of growing bacterial threat

Emerging strep bacterium causes same range of diseases as its flesh-eating sibling, Group A Strep

Houston Methodist

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Houston Methodist logo

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Credit: Houston Methodist

Scientists at Houston Methodist Research Institute have discovered that a fast‑rising strep bacterium comes in more forms than expected, including ones that may lead to life-threatening infections.  

The study, led by James Musser, M.D., Ph.D., chair of the Department of Pathology and Genomic Medicine and director of the Center for Infectious Diseases at Houston Methodist, is published in Microbiology Spectrum. It is the largest U.S. study investigating Streptococcus dysgalactiae subspecies equisimilis (SDSE) at this level, as these strep infections are increasing worldwide.  

The bacterium is most closely related to the flesh-eating Group A Strep, which causes illnesses ranging from mild strep throat and fever to severe conditions like blood infections and necrotizing fasciitis (flesh-eating disease).  SDSE was originally considered rare and was believed to mostly infect people who already had other health issues. 

First author, Lydia Pouga, Ph.D., research scientist at Houston Methodist said, by using whole-genome sequencing to analyze more than 800 patient samples, the researchers discovered 44 distinct variants of the bacterium, an insight older testing methods did not provide. 

“We discovered that certain strains caused specific types of infection,” Pouga said. “For example, one type of strain was associated with skin infections, another type was associated with blood infections and yet another strain was associated with throat infections. This is the first time we’ve seen such strong associations between strains and specific infections across a large patient population.” 

 

Pouga said the study provides critical genetic data to understand how the bacterium spreads, changes and causes infections. The information will help deliver insights that can improve diagnosis, infection control and future vaccine planning. 

 

Musser’s lab is renowned for using an integrated interdisciplinary research approach to unravel new information about infections caused by group A Streptococcus (GAS), which is responsible for more than 700 million cases of human disease each year globally. Jim Henson, creator of the Muppets, died of a similar form of the disease in 1990. 

 

Other authors include Houston Methodist researchers Stephen Beres, Randall Olsen, Wesley Long and Edward Graviss. The study was funded in part by the Fondren Foundation.

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Journal

Microbiology Spectrum