Extreme Cold Temperatures Research Articles

Investigation on Novel Ultralight Weight Thermally Insulated Fireproof Composite

Abstract This study highlights the performance of ultra-lightweight fireproof composite. Polyacrylonitrile (PAN) based carbon fiber (CF) has been reinforced in Polyetherimide (PEI) polymer to develop the composite. The Surface of CF and PEI film was modified by low-pressure plasma to improve the bonding strength between matrix and reinforcement. The polymeric composite was fabricated by compression moulding with a pressure of 2 bar, temperature of 380 ℃ and holding time of 30 min. CF/PEI composite was used to make a hybrid composite by layering of silicone foam in between the layers. The hybrid composite was exposed to a Bunsen burner under sustained flame for a duration of 10 minutes. The composite panel's flame-facing side reached 676.2°C after 10 minutes of fire exposure, while the temperature on the other side only reached 58.2°C. The fabricated hybrid composite was exposed to very low temperature in order to test its ability of thermal insulation under extreme cold temperature. Over the specific period of testing, the temperature of the dry ice decreased from 25°C to -3.1°C. After exposure to fire, only minimal loss of material was observed. The hybrid composite of carbon fiber and PEK film, sandwiched between silicone foam, exhibits excellent fire resistance due to its high limiting oxygen index (LOI). This composite is considered to be among the best thermally insulating and fire-resistant materials. Thermogravimetric analysis (TGA) of carbon fiber and PEI-Carbon fiber composite was performed to determine the optimal processing temperature of compression moulding for the composite, upon heating, it showed a modest weight decrease of 6.053%. The composite shows a significant improvement of impact resistance, compressive strength and thermal stability. A simulation model was developed under Ansys fluent software for both heating and cooling. The analysis of developed model also shows similar results.


Exploring the short-term effects of extreme temperatures on tuberculosis incidence in Shantou, China: a Coastal City perspective.

Coastal cities, due to their proximity to coastlines and unique climatic conditions, face growing challenges from extreme temperature events associated with climate change. Research on the impact of extreme temperatures on tuberculosis (TB) in these cities is limited, and findings from different regions lack consensus. This study focuses on Shantou, a coastal city in China, to investigate the influence of extreme temperatures on TB within this distinctive geographical context. Distributed Lag Non-Linear Models (DLNM) were employed to evaluate the effect of extreme temperatures on TB incidence risk in Shantou, a coastal city in China, spanning from 2014 to 2021. Daily TB case data were provided by the Shantou Tuberculosis Prevention and Control Institute. Daily meteorological information was sourced from the Reliable Prognosis website, while daily air pollutant data were obtained from the China Air Quality Online Monitoring and Analysis Platform. The study revealed a significant association between extreme temperatures and TB incidence, with the impact peaking at a lag of 27 days after exposure. Notably, extreme cold temperatures led to a temporary decrease in TB incidence with a lag of 1-2 days. Subgroup analysis indicated that males had a notably higher risk of TB under extreme temperature conditions compared to females. Additionally, individuals aged 65 years and above showed a significant cumulative effect in such conditions. This research enhances our comprehension of the effects of extreme temperatures on TB in coastal cities and carries substantial public health implications for TB prevention in China.

Cryoablation in Chronic Pain Management: A Narrative Review

Abstract Cryoneurolysis is a technique of applying extreme cold temperatures to specific sensory nerves, causing a prolonged period of loss of conduction through that nerve. This technique has found widespread application in the field of interventional pain medicine in a variety of conditions including chronic postsurgical pain, phantom limb pain (PLP), and cancer pain. Its use in chronic pain states has been aided further by the advent of handheld cryoneurolysis devices and the widespread use of ultrasonographic imaging to guide and target nerves accurately. Chronic pain states – chronic knee pain from osteoarthritis, refractory PLP, temporomandibular disorders, cervicogenic headaches, low back pain, different peripheral neuropathies, and metastatic bone tumor pain – are some of the conditions where cryoneurolysis has been proven to benefit patients in cases where the symptoms were refractory to other conventionally used modalities. Chronic pain is a complex and multifaceted condition and hence requires a variety of individualized treatment approaches. Current research on this treatment method for chronic pain indicates that it carries low risk and, when used correctly, offers extended pain relief without causing motor function loss. This narrative review includes all types of scientific studies, published between 2010 and 2023, which were selected using a specific set of keywords through two different literature search engines. In conclusion, it explains how cryoneurolysis works to provide long-term pain relief and summarizes the latest evidence supporting its use in chronic pain management.

Harsh Environment-Tolerant, High Performance Soft Pressure Sensors Enabled by Fiber-Segment Structure and Plasma Treatment.

As the demand for specialized and diversified pressure sensors continues to increase, excellent performance and multi-applicability have become necessary for pressure sensors. Currently, flexible pressure sensors are primarily utilized in fields such as health monitoring and human-computer interaction. However, numerous complex extreme environments in reality, including deep sea, corrosive conditions, extreme cold, and high temperatures, urgently require the services of flexible devices. Here, a piezoresistive flexible pressure sensor based on expanded polytetrafluoroethylene/functionalized carbon nanotubes (EPTFE/FCNT) is proposed. Benefiting from the unique fiber-segment architecture, chemical stability, and strong chemical binding force between EPTFE and FCNT, the fabricated sensor exhibits remarkable sensing capabilities and can be employed in multifarious extreme environments. It demonstrates a sensitivity of 862.28kPa-1, a response time of 6-7ms, and a detection limit below 1Pa. Furthermore, it possesses a pressure resolution of 0.0018% under 111kPa and can withstand over 10,000 loading and unloading cycles under 1MPa. Additionally, the EPTFE/FCNT sensor retains its outstanding pressure response and work efficiency in extreme conditions such as an ultra-low temperature of -80°C, high temperature (200°C), acidic and alkaline corrosion, and underwater. These notable attributes enormously broaden the sensors' real-world application range.

Impact of temperature and relative humidity variability on children’s allergic diseases and critical time window identification

BackgroundThe effects of temperature and relative humidity on different types of children’s allergic diseases have not been comprehensively evaluated so far. This study aims to assess the impact of temperature and relative humidity variability on children’s allergic diseases and to identify the critical time window.MethodsWe collected outpatient data on allergen testing in children between July 2020 and January 2022 from the Affiliated Children’s Hospital of Nanjing Medical University. We defined the 1st, 10th, 90th, and 99th percentiles as extreme cold, moderate cold, moderate hot, and extreme hot for temperature, and as low, moderate high, and extreme high for relative humidity, respectively. A distributed lag nonlinear model (DLNM) combined with a binomial regression model was used to assess the possible nonlinear relationship at different periods. Subgroup analysis by gender and age was conducted.ResultsWe found that extreme and moderate cold temperatures were positively associated with skin allergies and total allergies (28 days: OR = 4.69, 95% CI: 2.88, 7.63; OR = 3.36, 95% CI: 2.39, 4.73) and (28 days: OR = 3.76, CI: 2.43, 5.81; OR = 2.71, 95% CI: 2.00, 3.68), respectively. Moderate and extreme hot temperatures were negatively associated with food allergies (28 days: OR = 0.13, 95% CI: 0.04, 0.41 and OR = 0.04; 95% CI: 0.01, 0.27). Low relative humidity was negatively associated with respiratory allergies, skin allergies, and total allergic diseases (28 days: OR = 0.26, 95% CI: 0.10, 0.71; OR = 0.29, 95% CI: 0.15, 0.55; and OR = 0.42, 95% CI: 0.26, 0.68). Meanwhile, extreme high relative humidity was negatively associated with respiratory allergies, and positively associated with skin allergies, food allergies, and total allergies (28 days: OR = 0.16, 95%CI: 0.07, 0.37; OR = 3.60, 95% CI: 2.52, 5.14; OR = 15.61, 95% CI: 3.23, 75.56; and OR = 2.33, 95% CI: 1.73, 3.15). A stronger relationship between temperature, relative humidity, and allergic diseases was observed in children under 5 years, specifically girls.ConclusionsOur study provides evidence that temperature and relative humidity variability may be associated with allergic diseases, however, the directionality of the relationship differs by allergic type.

Cold Waves Accelerate the Spread of Infectious Diseases

AbstractClimate change is creating a new era of infectious disease crises, further exacerbated by extreme weather. However, the relationship between extreme weather and infectious disease remain unclear. Here, we provide a new quantitative study on the impact of cold wave on COVID‐19 as an example. We found that during cold waves, extreme cold temperatures coupled with rapid aerosol transport accelerated COVID‐19 outbreaks. It directly increased the number of COVID‐19 cases in Beijing by 28.1% in the winter of year 2022. More urgently, cold temperatures led to a higher risk of death during infectious disease outbreaks, with a 7.07% increase in confirmed deaths and a 16.61% increase in excess mortality. Our findings emphasize the urgent need to promote a synergistic policy for responding to infectious diseases during cold wave disasters in order to minimize the risk of death among the elderly and those with underlying diseases.

Winter break? The effect of overwintering on immune gene expression in wood frogs

Among terrestrial ectotherms, hibernation is a common response to extreme cold temperatures and is associated with reduced physiological rates, including immunity. When winter wanes and temperatures increase, so too do vital rates of both ectothermic hosts and their parasites. Due to metabolic scaling, if parasite activity springs back faster than host immune functions then cold seasons and transitions between cold and warm seasons may represent periods of vulnerability for ectothermic hosts. Understanding host regulation of physiological rates at seasonal junctions is a first step toward identifying thermal mismatches between hosts and parasites. Here we show that immune gene expression is responsive to transitions into and out of the cold season in a winter-adapted amphibian, the wood frog (Lithobates sylvaticus), and that frogs experienced parasitism by at least two nematode species throughout the entirety of the cold season. In both splenic and skin tissues, we observed a decrease in immune gene expression going from fall to winter, observed no changes between winter and emergence from hibernation, and observed increases in immune gene expression after hibernation ended. At all timepoints, differentially expressed genes from spleens were more highly enriched for immune system processes than those from ventral skin, especially with respect to terms related to adaptive immune processes. Infection with nematode lungworms was also associated with upregulation of immune processes in the spleen. We suggest that rather than being a period of stagnation, during which physiological processes and infection potential cease, the cold season is immunologically dynamic, requiring coordinated regulation of many biological processes, and that the reemergence period may be an important time during which hosts invest in preparatory immunity.

Germination response to winter temperature changes with seed shape and length of temperature exposure.

In many regions, the climate is changing faster during winter than during the other seasons, and a loss of snow cover combined with increased temperature variability can expose overwintering organisms to harmful conditions. Understanding how species respond to these changes during critical developmental times, such as seed germination, helps us assess the ecological implications of winter climate change. To address this concern, we measured the breaking of seed dormancy and cold tolerance of temperate grassland species in the lab and field. In the lab, we ran germination trials testing the tolerance of 17 species to an extreme cold event. In the field, we deployed seeds of two species within a snow manipulation experiment at three locations and measured germination success biweekly from seeds subjected to ambient and reduced snow cover from winter into spring. From lab trials, cold tolerance varied among species, with seed germination decreasing <10%-100% following extreme cold events. Cold tolerance was related to seed traits, specifically less round seeds, seeds that required cold stratification, and seeds that mature later in the season tended to be more impacted by extreme cold temperatures. This variation in seed cold tolerance may contribute to altered community composition with continued winter climate change. In the field, germination increased through late winter, coinciding with the accumulation of days where temperatures were favorable for cold stratification. Through spring, germination success decreased as warm temperatures accumulated. Collectively, species-specific seed cold tolerances and mortality rates may contribute to compositional changes in grasslands under continued winter climate change.

Association of ambient temperature on acute ischemic stroke in Yancheng, China

BackgroundAcute ischemic stroke (AIS) is a major global public health issue. There is limited research on the relationship between ambient temperature and AIS hospital admissions, and the results are controversial. Our objective is to assess the short-term impact of ambient temperature on the risk of AIS hospital admissions in Yancheng, China.MethodsWe collected data on daily AIS hospital admissions, meteorological factors, and air quality in Yancheng from 2014 to 2019. We used Poisson regression to fit generalized linear models and distributed lag non-linear models to explore the association between ambient temperature and AIS hospital admissions. The effects of these associations were evaluated by stratified analysis by sex and age.ResultsFrom 2014 to 2019, we identified a total of 13,391 AIS hospital admissions. We observed that the influence of extreme cold and heat on admissions for AIS manifests immediately on the day of exposure and continues for a duration of 3–5 days. Compared to the optimal temperature (24.4 °C), the cumulative relative risk under extreme cold temperature (-1.3 °C) conditions with a lag of 0–5 days was 1.88 (95%CI: 1.28, 2.78), and under extreme heat temperature (30.5 °C) conditions with a lag of 0–5 days was 1.48 (95%CI: 1.26, 1.73).ConclusionsThere is a non-linear association between ambient temperature and AIS hospital admission risk in Yancheng, China. Women and older patients are more vulnerable to non-optimal temperatures. Our findings may reveal the potential impact of climate change on the risk of AIS hospital admissions.

Amplified warming of North American cold extremes linked to human-induced changes in temperature variability

How global warming is impacting winter cold extremes is uncertain. Previous work has found decreasing winter temperature variability over North America which suggests a reduction in frequency and intensity of cold extremes relative to mean changes. However, others argue that cold air outbreaks are becoming more likely because of Arctic-induced changes in atmospheric circulation. Here we show that cold extremes over North America have warmed substantially faster than the winter mean temperature since 1980. This amplified warming is linked to both decreasing variance and changes in higher moments of the temperature distributions. Climate model simulations with historical forcings robustly capture the observed trends in extremes and variability. A pattern-based detection and attribution analysis shows that the changes in variability are detectable in observations and can be attributed to human influence. Our results highlight that human emissions are warming North American extreme cold temperatures beyond only shifting the winter mean temperature.

Temperature-induced germination pulses above the alpine tree line

ABSTRACT Subject to a long research tradition, the tree line is considered an important biogeographic indicator of climate changes and associated range shifts. Realized tree line positions and the potential tree line isotherm are, however, rarely in equilibrium because trees are unable to track rapid temperature variations. Often ignored in tree line research, this dilemma constrains the suitability of tree line trees for understanding alpine vegetation responses to anthropogenic warming. Here, we present combined dendrochronological and wood anatomical assessments of 1,351 seedlings and saplings from three subalpine forest species—larch (Larix decidua Mill.), pine (Pinus cembra L.), and spruce (Picea abies)—collected between ~2,200 and 2,600 m.a.s.l. in the Swiss Alps. We found evidence for temperature-induced, pulse-like seedling germination, rather than a continuous, long-term upward movement. Though the species spread across overlapping elevational ranges, larch was found at the highest elevations, followed by spruce and pine. Surprisingly, we found a varying age structure, with no sign of decreasing age toward higher elevations. Spring and summer temperatures promoted germination pulses, but postgermination survival was likely facilitated by species-specific plant traits. Our study demonstrates the importance of seedling and sapling data from above the tree line to understand prevailing vegetation dynamics at cold temperature extremes and also suggests future tree line advancement in the Swiss Alps.

Extreme Temperatures and Stroke Mortality: Evidence From a Multi-Country Analysis.

Extreme temperatures contribute significantly to global mortality. While previous studies on temperature and stroke-specific outcomes presented conflicting results, these studies were predominantly limited to single-city or single-country analyses. Their findings are difficult to synthesize due to variations in methodologies and exposure definitions. Within the Multi-Country Multi-City Network, we built a new mortality database for ischemic and hemorrhagic stroke. Applying a unified analysis protocol, we conducted a multinational case-crossover study on the relationship between extreme temperatures and stroke. In the first stage, we fitted a conditional quasi-Poisson regression for daily mortality counts with distributed lag nonlinear models for temperature exposure separately for each city. In the second stage, the cumulative risk from each city was pooled using mixed-effect meta-analyses, accounting for clustering of cities with similar features. We compared temperature-stroke associations across country-level gross domestic product per capita. We computed excess deaths in each city that are attributable to the 2.5% hottest and coldest of days based on each city's temperature distribution. We collected data for a total of 3 443 969 ischemic strokes and 2 454 267 hemorrhagic stroke deaths from 522 cities in 25 countries. For every 1000 ischemic stroke deaths, we found that extreme cold and hot days contributed 9.1 (95% empirical CI, 8.6-9.4) and 2.2 (95% empirical CI, 1.9-2.4) excess deaths, respectively. For every 1000 hemorrhagic stroke deaths, extreme cold and hot days contributed 11.2 (95% empirical CI, 10.9-11.4) and 0.7 (95% empirical CI, 0.5-0.8) excess deaths, respectively. We found that countries with low gross domestic product per capita were at higher risk of heat-related hemorrhagic stroke mortality than countries with high gross domestic product per capita (P=0.02). Both extreme cold and hot temperatures are associated with an increased risk of dying from ischemic and hemorrhagic strokes. As climate change continues to exacerbate these extreme temperatures, interventional strategies are needed to mitigate impacts on stroke mortality, particularly in low-income countries.

Extreme Temperatures, Birth Outcomes, and Social Inequalities: Evidence from South China

Abstract The impacts of climate change on health are a critical public health issue, but the association between extreme temperatures and birth outcomes remains poorly understood. This paper links over 1 million birth records from Dongguan, China, between 2004 and 2013, to meteorological data. We investigate the relationship between extreme temperatures and birth outcomes and explore the heterogeneity among different demographic and socioeconomic factors, including maternal migrant status, education level, and mode of delivery. We find that one percentage increase in the number of days exposed to extreme heat during pregnancy is associated with a reduction in birth weight of 2.31 g and a 2% increase in odds of low birth weight (LBW), while exposure to extreme cold temperatures is associated with a reduction in birth weight (0.66 g) and an increase in the risk of LBW (1%). The association between extreme high temperatures and adverse birth outcomes is stronger for groups with disadvantaged social status. Specifically, the migrant group (for extreme heat exposure, local residents, −0.37 g; intraprovincial migrants, −2.75 g; out-of-province migrants, −2.49 g), the less-educated group (for extreme heat exposure, middle school or below, −2.47 g; high school or above, −1.66 g), and the group with vaginal birth [for extreme heat exposure, cesarean sections (C-sections), −1.56 g; vaginal birth, −2.62 g] are more sensitive to extreme weather conditions. Our study provides further evidence about the association of extreme temperatures with birth outcomes and for vulnerable groups of pregnant women.

Viscous Elastic Asphalt Characteristics of Cariphalte Modification with Addition of Gilsonite Viewed from Phase Angle Value

Performance Grade (PG) Bitumen is bitumen that is graded based on its performance at different temperatures. In the Superpave grading system, asphalt binders are classified according to their performance in extreme hot and cold temperatures and are referred to as performance grade (PG) asphalt. The main objective of assessing and selecting asphalt binder using the PG system is to ensure that the binder has properties suitable for the environmental conditions in the field. Cariphalte is a premium grade polymer modified bitumen used in road and airport construction and other similar applications. Cariphalte is a Styrene Butadine Styrene (SBS) modified bitumen. The SBS in Cariphalte ensures the formation of a 3-dimensional network in the bitumen thereby reducing the temperature susceptibility and increasing the stiffness modulus at high temperatures. Cariphalte is also resistant to oxidation, reducing deformation and slowing secondary solidification. To get an idea of the improvement in rheological properties due to the addition of gilsonite, tests were carried out on a mixture of cariphalte and gilsonite asphalt with 6 variations of gilsonite content. The tests carried out include basic rheological properties testing and mechanistic rheological properties testing. From this research, the test results showed that at the same temperature, asphalt with the addition of 0% gilsonite had the smallest phase angle (δ) compared to asphalt using the addition of gilsonite. This explains that the addition of gilsonite can increase the phase angle (δ) value of PG-76 asphalt, which makes the asphalt material have thicker characteristics.

From freezing to functioning: cellular strategies of cold-adapted bacteria for surviving in extreme environments.

The ability of cold-adapted bacteria to survive in extreme cold and diverse temperatures is due to their unique attributes like cell membrane stability, up-regulation of peptidoglycan biosynthesis, increased production of extracellular polymeric substances, and expansion of membrane pigment. Various cold-adapted proteins, including ice-nucleating proteins (INPs), antifreeze proteins (AFPs), cold shock proteins (Csps), and cold-acclimated proteins (CAPs), help the bacteria to survive in these environments. To sustain cells from extreme cold conditions and maintain stability in temperature fluctuations, survival strategies at the molecular level and their mechanism play significant roles in adaptations in cryospheric conditions. Furthermore, cold shock domains present in the multifunctional cold shock proteins play crucial roles in their adaptation strategies. The considerable contribution of lipopeptides, osmolytes, and membrane pigments plays an integral part in their survival in extreme environments. This review summarizes the evolutionary history of cold-adapted bacteria and their molecular and cellular adaptation strategies to thrive in harsh cold environments. It also discusses the importance of carotenoids produced, lipid composition, cryoprotectants, proteins, and chaperones related to this adaptation. Furthermore, the functions and mechanisms of adaptations within the cell are discussed briefly. One can utilize and explore their potential in various biotechnology applications and their evolutionary journey by knowing the inherent mechanism of their molecular and cellular adaptation to cold climatic conditions. This review will help all branches of the life science community understand the basic microbiology of psychrophiles and their hidden prospect in life science research.

Association between ambient temperature and risk of notifiable infectious diseases in China from 2011 to 2019

ABSTRACT Previous studies on temperature and infectious diseases primarily focused on individual disease types, yielding inconsistent conclusions. This study collected monthly data on notifiable infectious disease cases and meteorological variables across 7 provinces in China from 2011 to 2019. A distributed lag nonlinear model was used to evaluate the association between ambient temperature and infectious diseases within each province, and random meta-analysis was applied to evaluate the pooled effect. Extreme hot temperature (the 97.5th percentile) was positively associated with the risk of respiratory infectious diseases with the relative risk (RR) of 1.45 (95%CI: 1.01–2.08). Conversely, extreme cold temperature (the 2.5th percentile) was negatively associated with intestinal infectious diseases and zoonotic diseases and vector-borne diseases, reporting RRs of 0.43 (95%CI: 0.30–0.60) and 0.46 (95%CI: 0.38–0.57), respectively. This study described the nonlinear association between ambient temperature and infectious diseases with different transmission routes, informing comprehensive prevention and control strategies for temperature-related infectious diseases.

The gut microbiota facilitate their host tolerance to extreme temperatures.

Exposure to extreme cold or heat temperature is one leading cause of weather-associated mortality and morbidity in animals. Emerging studies demonstrate that the microbiota residing in guts act as an integral factor required to modulate host tolerance to cold or heat exposure, but common and unique patterns of animal-temperature associations between cold and heat have not been simultaneously examined. Therefore, we attempted to investigate the roles of gut microbiota in modulating tolerance to cold or heat exposure in mice. The results showed that both cold and heat acutely change the body temperature of mice, but mice efficiently maintain their body temperature at conditions of chronic extreme temperatures. Mice adapt to extreme temperatures by adjusting body weight gain, food intake and energy harvest. Fascinatingly, 16 S rRNA sequencing shows that extreme temperatures result in a differential shift in the gut microbiota. Moreover, transplantation of the extreme-temperature microbiota is sufficient to enhance host tolerance to cold and heat, respectively. Metagenomic sequencing shows that the microbiota assists their hosts in resisting extreme temperatures through regulating the host insulin pathway. Our findings highlight that the microbiota is a key factor orchestrating the overall energy homeostasis under extreme temperatures, providing an insight into the interaction and coevolution of hosts and gut microbiota.

Neutraceutical and Pharmaceutical Potential of Fagopyrum esculentum (Linn.) Moench.

Buckwheat is a gluten-free pseudocereal grown annually in hilly regions of India. It belongs to family Polygonaceae and genus Fagopyrum. Buckwheat is adaptable to extreme cold temperature, stress conditions of water making it a sustainable crop. In India, twenty species of buckwheat are cultivated across various hilly regions. Out of these only nine species have desirable nutritional value and two are commonly grown. They are Fagopyrum esculentum (Common buckwheat) and Fagopyrum tartaricum (Tartary buckwheat). Buckwheat has good amount of nutrients and many health benefits. Buckwheat has been used in the gluten free diet for those suffering from celiac disease. It can be used for the prevention of obesity and diabetes as they have high total dietary fibre and soluble dietary fibre. It is commonly used grain in the name of Kuttu in Indian society during fasting. The present study aims at establishing the Neutraceutical and Pharmaceutical utility of potential alternative to conventional food grains as mentioned in the contemporary texts.

Fuel-use strategies at ultrahigh elevations on the Tibetan Plateau since the last deglaciation

Often referred to as the “Third Pole”, the Tibetan Plateau combines high elevation, extreme cold temperatures, hyper-aridity, and low oxygen levels. The strategy that early populations adopted to adapt to the harsh environment of the Tibetan Plateau has always attracted much attention. However, relevant studies have predominantly focused on the relatively lower elevation northeastern part of the Tibetan Plateau (<3000 m a.s.l.), with limited study in areas of ultrahigh elevation (>3500 m a.s.l.). This paper employed the flotation method and charcoal analysis of survey profiles from thirteen archaeological sites in the ultrahigh-elevation region of the middle Yarlung Zangbo River basin on the southern Tibetan Plateau, and finds that ancient people have been active in this region since the last deglaciation. The primary fuel sources used by ancient populations were small trees such as sea buckthorn (Hippophae gyantsensis) and shrubs such as juniper (Juniperus). The widespread use of undesirable wood (dwarf thorny shrub) like Sophora moorcroftiana and Caragana, along with the phenomenon of many sites relying on a single taxon, reflects the prevalent issue of fuel scarcity in this ultrahigh-elevation region. This might have been a driving factor for the early adoption of animal dung as a primary fuel source by ancient populations on the southern Tibetan Plateau.

Nested‐Cell Architecture and Molecular Surface Modification Enabled 10 Megapascals Range High Sensitivity Flexible Pressure Sensors for Application in Extreme Environment

AbstractFlexible pressure sensors with high sensitivity over a broad sensing range are of great value in daily life and highly desired in various extreme environment, from human motion inspection to heavy industrial robots to high energy radiation and extremely cold/high temperature environments. However, it remains a significant challenge for a single pressure sensor to simultaneously possess high sensitivity and broad detection range due to the trade‐off between these two properties. Here, a high‐performance pressure sensor is developed based on flexible modified silicon rubber/functionalized carbon nanotube (MSR/FCNT). The designed nested‐cell architecture and molecular surface modification strategy endow the pressure sensor with high sensitivity (&gt;28 kPa−1) over 10 MPa sensing range, an ultralow detection limit (≈0.94 Pa), an ultrahigh pressure resolution (0.0075%) at a pressure of 3 MPa, and a low fatigue over 10 000 repetitive cycles even at an extremely high pressure of 5 MPa. Furthermore, the resulting sensor presents excellent durability after freezing at extreme cold temperature (−80 °C) as well as resistance to high temperature (200 °C) and high‐energy X‐ray radiation. The proposed nested‐cell architecture is a generic strategy for porous materials to achieve broad range high sensitivity.