Natural Cycle Research Articles

The menopausal transition and multiple physiologic measures of early brain health in the Coronary Artery Risk Development in Young Adults study.

This study proposed to investigate the cross-sectional and longitudinal associations of menopausal status with physiologic brain magnetic resonance imaging measures. The sample included women from the Coronary Artery Risk Development in Young Adults study who self-reported their reproductive histories and participated in the brain magnetic resonance imaging substudies at the year 25 (n = 292) and year 30 (n = 258) follow-up examinations. Menopausal status was classified based on natural menstrual cycle regularity/cessation at both time points. Gray matter cerebrovascular reactivity (CVR) was calculated as mean percent change in blood oxygen level-dependent signals in activated voxels following a breath-hold challenge. Gray matter cerebral blood flow (CBF) was assessed using pseudo-continuous arterial spin labeling. Linear regression models were used to examine cross-sectional and longitudinal associations of menopausal status with gray matter CVR and CBF after adjustment for potential age-related covariates. Women were mean age 50 years at year 25; 37% were Black; and 46% were postmenopausal. Relative to premenopause or perimenopause, postmenopause was associated with lower gray matter CVR at year 30 cross-sectionally (1.86% vs 1.69%, P = 0.03, respectively) and longitudinally for women who were postmenopausal at both time points (-0.32% [95% CI, -0.63% to -0.02%]) after covariate adjustment. Mean CVR values were also lower for these women when compared with women who remained premenopausal or perimenopausal (1.71% compared with 2.04%, respectively). Menopausal status was unrelated to either concurrent or longitudinal gray matter CBF. These findings suggest that the ability of vessels to adapt in response to hypercapnia may be impaired during menopause, even within a relatively short time window.

The characteristics and changes of the natural social binary water cycle in the Upper Yellow River Basin under the influence of climate change and human activities: A review

The characteristics and changes of the natural social binary water cycle in the Upper Yellow River Basin under the influence of climate change and human activities: A review

Genesis of artesian waters

Mankind has entered the era of fresh water scarcity. And the questions of the origin of these waters, as well as the methods of effective search for underground fresh water, become fundamental for the assessment of the prospects of water supply of the Earth's population not only in theoretical, but also in applied values. The article considers the volcanic-marine paradigm of artesian water genesis, which allows a logical explanation of a number of deep freshwater phenomena that cannot be resolved by other theories. The main consequences of the volcanic-marine paradigm are: (a) artesian water is recoverable, (b) deep freshwater resources are included in the water cycle in nature like groundwater, (c) the problem of extracting potable artesian water is not a resource problem for mankind, but a technological problem. At present, artesian water is searched for by drilling wells (direct method) and by geophysical methods of groundwater exploration—electrical survey, seismic survey and magnetic resonance method. At the same time, the great depth of artesian water, up to 1000 m, makes it difficult to locate it using geophysical methods. The article considers the geophysical method of direct detection of artesian water in various geological structures at great depths. This method and the service based on it have been named “Geodirect RSS/NMR”. Their physical basis is the resonance between the pre-recorded spectrum of the sought substance (in our case, artesian water) and the spectrum of radiations recorded by the satellite instrumentation in the infrared range. The presence of resonance allows direct identification of artesian water flows and reservoirs without interpretation of indirect data.

Impact of energy integration on post-combustion CO2 capture: A comparative analysis of chemical absorption and calcium looping technologies in coal-fired and natural gas combined cycle power plants

Chemical absorption (Che) and calcium looping (CaL) have been recognized as the promising technologies for post-combustion CO2 capture (PCC) applied in fossil fuel power plants. However, there is a lack of understanding of how the energy integration affects the performance difference of the two separation technologies employed for the retrofitted coal-fired (CFPP) and natural gas combined cycle (NGCC) power plants. Thus, this study aims to provide a new perspective by investigating power generation fuel and heating fuel from energy conversion and transfer pathways. Results indicate that in the case of CFPP-PCCs, adopting the CaL technology can enhance the initial parameters of the steam cycle and reduce the heat transfer temperature difference for the utilization of heating fuel, where the heat transfer exergy destruction of heating fuel drops from 27.9 % to 15.1 % compared to the Che capture system. Conversely, for NGCC-PCCs, due to the superior performance of the combined cycle, the adoption of the CaL technology undermines the advantages of the heat transfer and power generation units, resulting in inferior performance compared to the Che capture system in most conditions. Results implicate that the degree of difference in energy conversion and transfer pathways between the power generation fuel and the heat supply fuel directly determines the performance of the capture system. Thus, concentration CO2 along with the efficient fuel conversion will be a promising direction for the innovation of capture technologies.

C2 Product Selectivity by 2D-Nanosheet of Layered Zn-doped Cu2(OH)3(NO3)- A Pre-Catalyst for Electrochemical CO2 Reduction.

The natural carbon cycle cannot mitigate and recycle the excess CO2 in the atmosphere, leading to a continuous rise in the global temperature. Electrochemical conversion of CO2 is one of the useful methods to utilise this anthropogenic CO2 and convert it into value-added chemicals. However, this process suffers the challenges of product selectivity and good Faradaic efficiency. In our current work, we report the role of Zn-doping in the 2D-Nanosheet of Cu2(OH)3(NO3)- a pre-catalyst that undergoes the in situ transformation into metallic state along with surface reconstruction. Our studies show, in the aqueous medium, the optimum amount of Zn plays a crucial role in the production of ethanol with the Faradaic efficiency of ∼45.2% though C-C coupling. Temperature-programmed desorption studies conclude that Zn increases the product selectivity for CO adsorption on Cu2(OH)3(NO3) nanosheets, further facilitating the C-C coupling at higher negative potential. The detailed XPS studies also reveal that the in-situ conversion of Cu2+ to Cu0 and Cu+ at negative potential contributes to the production of C2 products. The post-catalytic microstructural and spectroscopic studies converge to this point thatcumulative effect of oxidation state, surface reconstruction, as well as the presence of Zn modulates overall Faradaic efficiency for ethanol formation.

Global Mean Surface Temperature: What Can We Learn from the Trajectory over a Millions-year Span?

Global mean surface temperature serves as a crucial metric in understanding the Earth’s climate dynamics, providing insights into long-term climate trends and variability. Over the course of a million years, the trajectory of global temperatures has been shaped by a multitude of factors, including natural climatic cycles, human activities, and external influences. By examining the historical trends and drivers influencing global mean surface temperature, researchers can gain valuable insights into the past, present, and future climate scenarios. This article delves into the intricate interplay of these factors and explores the lessons we can learn from studying the temperature trajectory over a million-year span.

Multiple spacer sequence typing of Coxiella burnetii carried by ticks in Gansu, China

BackgroundCoxiella burnetii is a zoonotic pathogen that causes Q fever and is found worldwide. Ticks serve as the primary reservoir, playing an important role in maintaining the natural cycle of C. burnetii. C. burnetii is transmitted to animals when ticks feed on their blood. However, information on C. burnetii infection in ticks remains limited, despite the widespread prevalence of the infection in humans and animals across China.MethodsIn this study, 192 engorged ticks were collected from Baiyin City of Gansu Province, China. The presence of Coxiella burnetii in ticks was specifically identified by detecting the IS1111 gene using nested polymerase chain reaction (nPCR). In addition, the 16S rRNA gene of C. burnetii was molecularly characterized using nPCR. A total of 10 spacer sequences (Cox 2, 5, 18, 20, 22, 37, 51, 56, 57, and 61) were amplified using PCR against positive specimens for MST analysis.ResultsAll collected ticks were identified as Hyalomma marginatum, and 90 of them tested positive for C. burnetii, with a positive rate of 46.9% (90/192). The 16S rRNA gene analysis showed that the novel C. burnetii variants detected in this study were closely related to other C. burnetii strains in the world. The allele codes found in the present study for loci Cox2-Cox5-Cox18-Cox20-Cox22-Cox37-Cox51-Cox56-Cox57-Cox61 were 8-4-9-5-7-5-2-3-11-6. This represents a novel combination of allele values, similar to MST28, currently designated as MST85 in the Multi Spacers Typing (MST) database.ConclusionOur results revealed the circulation of a novel MST genotype of C. burnetii in Baiyin City, Gansu Province, China. The detection of C. burnetii in ticks suggests a potential public health risk to the local human population.

Exploring residential energy efficiency measures and distribution of renewable energy generation through sector interactions: a case study in Visby, Sweden

Increased use of cogeneration in district heating (DH) systems is important in the pursuit towards a low-carbon society, particularly in light of the ongoing electrification across multiple sectors. Apart from reducing CO2 emissions, cogeneration also contributes to additional income for the DH system owner. Nonetheless, it is important to be aware that the economic and environmental performance of DH systems are directly connected to the energy use within DH networks. This research investigates sector interactions associated with the introduction of a biomass combined heat and power (CHP) and residential energy renovation according to (life cycle cost) LCC optimum and Swedish energy targets, with a focus on CO2 emissions and the system cost of the energy utility company. The study object consists of a DH system in Visby, Sweden, and 920 historic residential building undergoing energy renovation. The results show a profitability of 905–915 MSEK for the DH system with the integration of a CHP. Global CO2 emissions decrease by 32.6–33.1 ktonnes/year, 9.0–9.2 ktonnes/year, and 19.9–20.1 ktonnes/year, for marginal coal-condensing power (limited biofuel), natural gas combined cycle power (limited biofuel), and European average production, respectively. In addition, sensitivity analyses confirm the benefits of cogeneration related to both economics and CO2 emissions based on changes in key parameters of the DH system.

Role of Dual Specificity Phosphatase 1 (DUSP1) in influencing inflammatory pathways in macrophages modulated by Borrelia burgdorferi lipoproteins.

Borrelia burgdorferi , the agent of Lyme disease, encodes numerous lipoproteins that play a crucial role as a pathogen associated molecular pattern affecting interactions with tick- and vertebrate-host cells. Single cell transcriptomics validated using unbiased proteomics and conventional molecular biology approaches have demonstrated significant differences in gene expression patterns in a dose- and time-dependent manner following treatment of murine bone marrow derived macrophages with borrelial lipoproteins. Distinct populations of macrophages, alterations in immune signaling pathways, cellular energy production and mitochondrial responses were identified and validated using primary murine macrophages and human reporter cell lines. Notably, the role of Dual Specificity Phosphatase 1 (DUSP1) in influencing several inflammatory, metabolic and mitochondrial responses of macrophages were observed in these studies using known pharmacological inhibitors. Significant outcomes include novel strategies to interfere with immunomodulatory and survival capabilities of B. burgdorferi in reservoir hosts affecting its natural infectious life cycle between ticks and vertebrate hosts.

Wild yeast isolation by middle school students reveals features of populations residing on North American oaks.

Features of the natural life cycle of the budding yeast Saccharomyces cerevisiae were crucial to its domestication as a laboratory experimental model, especially the ability to maintain stable haploid clones and cross them at will to combine alleles via meiosis. Stable haploidy results from mutations in HO, which encodes an endonuclease required for haploid-specific mating-type switching. Previous studies found an unexpected diversity of HO alleles among natural isolates within a small geographic area. We developed a hands-on field and laboratory activity for middle school students in Denver, Colorado, USA to isolate wild yeast from oak bark, identify species via DNA sequencing, and sequence HO from S. cerevisiae isolates. We find limited HO diversity in North American oak isolates, pointing to efficient, continuous dispersal across the continent. By contrast, we isolated the "dairy yeast", Kluyveromyces lactis, from a tree <10 m away and found that it represents a new population distinct from an oak population in an adjacent state. The outreach activity partnered middle school, high school, and university students in making scientific discoveries and can be adapted to other locations and natural yeast habitats. Indeed, a pilot sampling activity in southeast Texas yielded S. cerevisiae oak isolates with a new allele of HO and, from a nearby prickly pear cactus, a heat-tolerant isolate of Saccharomyces paradoxus.

Clinical efficacy of Crinone on pregnancy outcomes in frozen embryo transfer: A retrospective study in the Chinese population.

The aim of this study was to retrospectively investigate the effect of Crinone vaginal gel on pregnancy outcomes in women undergoing natural cycle (NC) frozen embryo transfer (FET) and to obtain the most suitable population for its routine application. The 1613 women who underwent FET in the NC regimen [including the controlled ovulation stimulation protocol for the natural cycle, or the controlled ovulation stimulation protocol for the natural cycle (NC-COS)] from 2017 to 2021 were included. All patients were divided into 2 groups including Control group and Crinone group, which administered with or without Crinone vaginal gel. The key clinical information and between the 2 groups was recorded in detail. The results indicated that there were no statistical differences in blood β human chorionic gonadotropin (HCG) positive rate, clinical pregnancy, live birth, abortion (spontaneous and induced) and stillbirth between Control group and Crinone group. Moreover, Crinone could prevent spontaneous abortion. The spontaneous abortion rate in the Crinone group was 5.93% while this in control group was 8.32%. In the cohort exposed to Femoston, the preventive result was more significant (0/32 vs 5/15, P = .001). Furthermore, Crinone exhibited a significant protective effect on spontaneous abortion in 1520 patients who received no human menopausal gonadotropin (HMG) treatment. This study demonstrated that the Crinone could protect women against spontaneous abortion, especially in patients who do not need HMG or in combination with Femoston.

Equivalent Circuits for Exergy Flow in Thermodynamic Systems

Abstract The second law of thermodynamics explains the nature of all spontaneous processes, and it imposes a limit on the performance of all technologies, from heat engines to refrigerators. These limits are well described as early as Sadi Carnot's 1824 publication that established the field of thermodynamics; researchers later developed the concept of exergy, or the available work, that a thermodynamic system can produce when interacting with a specified environment. In this work, we describe a resistance analogy for thermodynamic systems, in which the need to remove entropy forces some amount of energy to leave the system as heat rejection. Specifically, it is the inverse temperature of the heat sink that resists energy flowing out of the system as heat rejection. An equivalent circuit can be drawn for any thermodynamic system, with energy flowing through different branches of the circuit. The different paths correspond to different energy and exergy flows, including the energy that must flow out of the system as heat rejection and, therefore, cannot contribute to the exergy content of the system. After establishing this equivalent circuit, it is applied to a natural gas combined cycle example problem, a desalination example problem, and a transient heating problem.

The Presence of Pigment Incontinence in Sinonasal Mucosal Melanoma.

Regression is an immunological phenomenon described in cutaneous melanoma whereby tumor is replaced with tumor-infiltrating lymphocytes, granulation tissue, and mature fibroblasts often accompanied by pigment incontinence (accumulation of melanin in the upper dermis). Pigment incontinence results in grossly pigmented lesions that may be mistaken for viable tumor and has not been described in sinonasal mucosal melanoma (SNMM). This study investigates the presence of regression and pigment incontinence in patients with SNMM. A retrospective chart review was conducted on SNMM patients from 2007 to 2023. Pathology slides from surgical resection were examined by two pathologists blinded to treatment information for the presence and extent of pigment-laden macrophages and other histopathologic features of regression. Seventeen patients with SNMM were included in this study who underwent surgical resection. Three patients received neoadjuvant therapy followed by surgical resection. Regression was present in 94% of patients and pigment incontinence was present in 65% of patients and occurred in both neoadjuvant treated patients and treatment naïve patients. All three patients with neoadjuvant treatment had evidence of pigment incontinence. This study highlights that SNMM often displays characteristics of regression. This study is one of the first to describe the presence of pigment incontinence in patients with SNMM. Pigment incontinence can be a part of the natural tumor life cycle and grossly pigmented lesions could easily be confused for melanoma especially after neoadjuvant therapy. Developing an understanding of regression and pigment incontinence within SNMM is important for diagnosis and clinical management. IV Laryngoscope, 2024.

Do white-footed mice, the main reservoir of the Lyme disease pathogen in the United States, clinically respond to the borrelial tenancy?

As white-footed mice, Peromyscus leucopus, are considered the primary animal reservoir of Borreliella burgdorferi sensu stricto (Bb), the main agent of Lyme disease (LD) in the United States, these animals represent the most relevant model to study borrelial spirochetes in the context of their natural life cycle. Previous studies have consistently demonstrated that although white-footed mice respond immunologically to the invasion of the Lyme pathogen, P. leucopus adults do not develop a clinically detectable disease. This tolerance, which is common for mammalian reservoirs of different pathogens, contrasts with detrimental anti-borrelial responses of C3H mice, a widely used animal model of LD, which always result in a clinical manifestation (e.g., arthritis). The current investigation is a follow-up of our recent study that already showed a relative quiescence of the spleen transcriptome for Bb-infected white-footed mice compared to the infected C3H mice. In an effort to identify the mechanism behind this tolerance, in this study, we have evaluated an extensive list of hematological and biochemical parameters measured in white-footed mice after their 70-day-long borrelial infection. Despite missing reference intervals for Peromyscus mice, our sex- and age-matched uninfected controls allowed us to assess the blood and serum parameters. In addition, for our assessment, we also utilized behavioral, immunological, and histological analyses. Collectively, by using the metrics reported herein, the present results have demonstrated clinical unresponsiveness of P. leucopus mice to the borrelial infection, presenting no restriction to a long-term host-pathogen co-existence.

Indigenous use and conservation of harbor seals (Phoca vitulina) at Yakutat, Alaska since the sixteenth century

Sustainable Indigenous resource use reflects balance between animal populations and levels of human consumption, influenced by natural cycles of faunal abundance, community size and subsistence needs, procurement technologies, and the requirements of trade or commodity production. Sustainability is “epiphenomenal” when animal populations are preserved, and community needs met, without deliberate measures to prevent overharvesting. Alternatively, Indigenous conservation—cultural practices that moderate use of a resource to prevent its depletion—may play a determinative role. In this study from the Tlingit community of Yakutat, Alaska in the Northwest Coast cultural region, we interweave Indigenous and scientific perspectives to trace the use and conservation of harbor seals (Phoca vitulina) from before Western contact through the Russian and American colonial periods to the present. Harbor seals, which concentrate in large numbers at a summer ice floe rookery near Hubbard Glacier, are the community's most important subsistence food and a key to its culture and history. The Smithsonian Institution and Yakutat Tlingit Tribe undertook collaborative research in historical ecology and archaeology in 2011–2014 including oral interviews with elders and subsistence providers, excavations at sealing sites, archaeofaunal analysis, historical and archival research, and consideration of climate cycles and biological regime shifts that influence the harbor seal population in the Gulf of Alaska. We compare technologies and hunting practices before and after Western contact, estimate harvest levels in different periods, and evaluate the effectiveness of traditional conservation practices that included hunting quotas enforced by clan leaders and the seasonal delay of hunting with firearms to prevent abandonment of the rookery by the seal herd.

Air Excess Coefficient and Irreversibility Value Analysis of Gas Turbines

Gas turbines used in natural gas cycle power plants have been researched in terms of energy efficiency. Gas turbines used in power generation plants have a very complex structure because they contain many components. In order to determine the thermodynamic performance of this system, the efficiency of each component and the increase in entropy of each component were calculated using exergy analysis. Irreversibility was chosen as the main parameter and used for thermodynamic optimization of production. The system consists of many components. An increase in the irreversibility of a single component causes an increase in the irreversibility of other components. The effect of gas turbine pressure ratio and excess air percentage on fuel consumption, fuel exergy, combustion chamber exergy change and irreversibility change was investigated. It was observed that the increase in compressor pressure ratio increased irreversibility. Maximum irreversibility was observed in the combustion chamber. Irreversibility was compared with the excess air used in the combustion chamber. The air excess coefficient was examined as percentages of 100%, 200%, and 300%, respectively. The compression pressure ratio was examined for air excess coefficient percentage values from 3 to 40.

Exogenous progesterone rescue in patients with low mid-luteal serum progesterone levels undergoing true natural vitrified-warmed blastocyst transfer.

To explore whether a 25mg subcutaneous progesterone daily rescue daily improves the reproductive outcomes in patients with low serum progesterone (P4) levels (7-10ng/mL), measured one day before true natural cycle (t-NC) frozen embryo transfer (FET). A cohort study of 192 women undergoing t-NC warmed blastocyst transfer. Patients were stratified into three different groups based on serum P4 levels on the FET-1day: patients who had serum P4 levels of 7-10ng/mL and underwent rescue progesterone administration (rescue group), patients with serum P4 levels of 7-10ng/mL without progesterone administration (non-rescue group), and patients with serum P4 > 10ng/mL on FET-1day (control group). The primary outcome was possible differences in live birth rate (LBR) between groups. The LBRs for the serum P4 7-10ng/mL without rescue, 7-10ng/mL with rescue, and > 10ng/mL (control) groups were 41%, 46%, and 52%, respectively (p = 0.61). The estimated adjusted probability of live birth for serum P4 7-10ng/mL without rescue, 7-10ng/mL with rescue, and > 10ng/mL (control) groups were also comparable: 43.5% (95% CI, 20.0-70.4%), 49.8% (95% CI, 28.1-71.6%), and 57.4% (95% CI, 44.0-69.8%), respectively. Serum P4 levels higher than 7ng/mL seem to secure LBRs in patients undergoing t-NC FET. A rescue policy consisting of a daily subcutaneous 25mg progesterone dose in patients with serum P4 levels 7-10ng/mL does not further enhance LBRs when compared to those patients with similar serum P4 levels without rescue.

Correlation between self-reported low back pain and morphological changes in abdominal wall muscles.

Morphological changes in the abdominal wall muscle in diastasis recti abdominis (DRA) patients with low back pain (LBP) symptoms and whether there is a wider interrectus distance (IRD) remain unclear. The aim of this study was to determine the correlation between DRA severity and LBP and the morphological differences in abdominal wall muscles between patients who presented with symptoms of LBP and those who were asymptomatic. A total of 57 postpartum DRA patients were enrolled, including 21 without LBP, 36 with LBP, and 30 healthy nulliparous women. The numerical rating scale (NRS) was used to evaluate the degree of LBP. The IRD and muscle thickness of the abdominal muscles were measured via an ultrasonography device at the end of a natural breathing cycle. The abdominal muscles of the rectus abdominis (RA), external oblique muscle (EO), and transversus abdominis (TrA) in the DRA patients were significantly thinner than those in the control group (p< 0.05), whereas the difference in the internal oblique muscle (IO) was not significant (p> 0.05). There were no statistically significant differences in abdominal muscle thickness or the IRD regardless of whether the patients with DRA had LBP symptoms, with similar findings between the NRS score and DRA severity (P> 0.05). In DRA patients within one year postpartum, no significant difference was found in the severity of DRA or abdominal muscles, regardless of whether they were complicated by LBP symptoms. Shortening the IRD alone may not be beneficial for improving LBP symptoms in DRA patients. The relationship between DRA and LBP and the role of the abdominal muscles in postpartum LBP should be interpreted with caution.

Comparative analysis of pregnancy outcomes in different time intervals following GnRH antagonist stimulation and modified natural frozen-thawed embryo transfers

To evaluate whether the interval between oocyte retrieval and frozen-thawed embryo transfer (FET) affects clinical outcomes using modified natural cycle (mNC) regimen following freeze-all GnRH antagonist stimulation. A total of 542 patients underwent first mNC-FET were divided into two groups: immediate (FET conducted in the first menstrual cycle after freeze-all) and delayed (FET performed in the second or subsequent menstrual cycle) groups. The immediate group was associated with a notably reduced duration between oocyte retrieval and transfer day (35.5 ± 5.8 vs. 88.7 ± 35.5 d, P < 0.001). Regarding pregnancy results, the immediate cycles resulted in comparable implantation rate (55.3% vs. 57.2%, P = 0.624), clinical pregnancy rate (66.9% vs. 72.2%, P = 0.236), abortion rate (16.1% vs. 12.7%, P = 0.402), ongoing pregnancy rate (59.0% vs. 65.0%, P = 0.204), and live birth rate (56.1% vs. 63.0%, P = 0.149) with the delayed cycles. After the multivariable logistic regression analysis, the difference in live birth outcome between the two regimens remained insignificant (immediate vs. delayed protocol: adjusted odds ratio = 0.87, 95% confidence interval= 0.56–1.33). Immediate mNC-FET following a freeze-all antagonist cycle displayed promising clinical outcomes and significantly shortened the time to conception compared to delayed FET.

Development of hybrid first principles – Artificial intelligence models for transient modeling of power plant superheaters under load-following operation

This paper develops different approaches for synergistic integration of physics-based models with data-driven models for modeling of high temperature power plant superheaters. Two types of data-driven models are developed, namely all-nonlinear static-dynamic neural network models as well as models obtained using a Bayesian machine learning approach. Series, integrated, and parallel coupling of first-principles models and data-driven models are proposed. Algorithms for solving the training problems for the data-driven models and for simulation of the hybrid models are developed. The developed approach is applied to high temperature power plant superheaters that face considerable modeling and measurement challenges. Measurement challenges arise due to harsh operating conditions that not only make placement of sensors difficult, but life of the placed sensors very limited. Modeling challenges arise due to complex inhomogeneous spatial distribution of flue gas and steam flowrates, especially under load-following operation and uncertainties in heat transfer characteristics because of multiple factors such as stochastic spatio-temporal variation of ash deposits on the superheater tubes in coal-fired power plants, internal oxide scale formation in the tubes, etc. First-principles two-dimensional differential–algebraic equation models of two industrial superheaters, one from a natural gas combined cycle plant and another from a coal-fired power plant, are developed. The results from the models are compared against industrial operational data. For all cases studied in this work, it is observed that both for steady-state and dynamic data, the hybrid models have much higher accuracy than when only the respective first-principles models are used. For example, during prediction of the average outside tube wall temperature of superheater tubes at the combined cycle power plant, the root mean squared error observed for the standalone first-principles model improved from 12.3 °C to 0.5 °C post hybridization with data-driven models. Similarly, while predicting the main steam outlet temperature in the coal-fired plant, the hybrid models resulted in reduction of the root mean squared error value from 19.5 °C to around 2 °C. In addition, the hybrid models yield highly resolved spatio-temporal temperature profiles that can be helpful for developing monitoring approaches of these critical components under load-following operation.