Search Results (46)

Background: Untargeted proteomics enables quantitative host cell protein (HCP) determination in biotherapeutics, yet no workflow has been validated under ICH Q2(R2) for regulated quality control. Methods: A prospective total-error (TE) validation of label-free ddaPASEF proteomics was performed. A stable isotope-labeled whole-proteome standard was spiked into NISTmAb at seven levels (20–80 ng) and analyzed in four independent assays (198 injections), supporting one-way random-effects ANOVA with Welch–Satterthwaite adjustment. Peptide-level identification error was evaluated by dual entrapment. Results: Empirical false-discovery proportions were below 1% at q = 0.01. Weighted least-squares regression (R² = 0.993) confirmed stable proportional compression with 81–85% recovery. Repeatability dominated the variance structure (median CV 2.7%); intermediate precision SD ranged from 0.69% to 3.81%. Both 95% β-expectation and 95/95 content tolerance intervals were contained within ±30% at all levels, defining a validated range of 20–80 ng. Abundance-stratified TE profiling revealed concentration-dependent calibration heterogeneity, with stratum-specific intervals within ±35% defining an abundance-aware LLOQ of 3.6 ppm (P95 = 3.87 ppm). Robustness under independent search software (FragPipe v24.0, CCC = 0.998) and cross-platform acquisition (Astral, CCC = 0.980) remained within ±30% limits. Conclusions: This constitutes the first prospective ICH Q2(R2)-aligned validation of untargeted proteomics for HCP quantification, with a transferable statistical framework for high-dimensional analytical methods. Full article

Irrigation depth plays a critical role in regulating soil water availability and root water uptake in perennial orchards, yet its mechanistic effects remain poorly understood in subtropical red-soil hilly regions characterized by strong evaporative demand and shallow effective soil water storage. Here, a field experiment was conducted in a citrus orchard with three irrigation depths—shallow (25 cm), intermediate (50 cm), and deep (100 cm)—under a uniform irrigation amount. Soil water dynamics, root traits, and root water uptake sources across a 0–200 cm soil profile were investigated using soil moisture monitoring, root morphological analysis, dual stable isotopes (δ²H and δ¹⁸O), and the MixSIAR Bayesian mixing model. Irrigation depth markedly restructured vertical soil moisture patterns, with the 40–120 cm layer identified as the most responsive zone. Intermediate irrigation maintained the highest and most stable soil water content in this layer, whereas shallow irrigation intensified surface drying and deep irrigation failed to improve water availability within the hydraulically active root zone. Root surface area and dry mass were maximized under intermediate irrigation, indicating enhanced root–soil coupling. Isotopic analysis revealed the strongest evaporative fractionation under shallow irrigation, while intermediate irrigation substantially alleviated surface evaporation. MixSIAR results further showed that shallow irrigation progressively increased reliance on surface soil water (up to 93% in November), whereas intermediate irrigation promoted coordinated uptake from shallow, middle, and deep soil layers, with deep soil water contributing up to 30.7% in November. These results demonstrate that irrigation depth exerts a stronger control over root water uptake strategies by stabilizing water availability within the active root zone and reducing non-productive evaporative losses. Optimizing subsurface irrigation depth therefore represents an effective pathway to improve water-use efficiency in citrus orchards of subtropical hilly regions. Full article

Nitrate in Baiyangdian Lake is directly linked to the sustainability of watershed ecological functions, acting as a key priority for regional ecological protection. Subsequent to the completion of a series of ecological restoration projects, its sources have undergone inevitable shifts, rendering the original pollution control framework incompatible with the new context. Thus, accurate identification of nitrate sources and their seasonal variation characteristics constitutes a core prerequisite for enhancing the targeting of pollution management. This study integrated dual stable isotopes (δ¹⁵N-NO₃⁻ and δ¹⁸O-NO₃⁻) in water and potential source samples, along with hydrochemical data, and applied the Bayesian stable isotope mixing model (MixSIAR) to elucidate the sources of NO₃⁻ in Baiyangdian Lake. The results indicated that denitrification exerted a weak influence on the isotopic composition of NO₃⁻ in Baiyangdian Lake. Plots of the NO₃⁻/Cl⁻ versus Cl⁻ ratios for water samples and δ¹⁵N-NO₃⁻ versus δ¹⁸O-NO₃⁻ ratios for both water samples and potential sources confirmed anthropogenic sources as the primary nitrate contributors. The δ¹⁵N-NO₃⁻ vs. 1/[NO₃⁻] plot revealed that the number of NO₃⁻ sources exceeded two. The MixSIAR model demonstrated that wastewater treatment plant (WWTP) discharge was the dominant source throughout the four seasons, accounting for 49–62% with the highest contribution in winter and the lowest in summer. Soil nitrogen release contributed 19–32%, reaching its annual peak in summer. Sediment release accounted for 11–13%, maintaining a relatively low contribution across all seasons. Chemical fertilizer, manure, and sewage (M&S), and atmospheric deposition each contributed less than 6.5%, with negligible contributions. A significant reduction in the contributions of sediment release and M&S reflected the optimization effect of long-term regional ecological restoration efforts. WWTPs point source discharge and seasonal non-point source input from soil nitrogen collectively constituted the core sources of nitrate in Baiyangdian Lake. These findings provide crucial scientific support for the precise source apportionment and differentiated management of nitrate pollution in the basin. Full article

Karst aquifers provide critical water resources in the Mediterranean region, yet climate change threatens their sustainability. This study integrates stable isotope analysis (δ²H, δ¹⁸O), hydrochemistry, and hydrological time series to characterize precipitation–groundwater dynamics in the Mt. Učka karst system (Croatia). Precipitation samples collected across an altitudinal gradient of approximately 1400 m and groundwater from three major groundwater sources were analyzed over a 2.5-year period. Precipitation exhibits pronounced isotopic variability with d-excess values indicating mixed Atlantic–Mediterranean moisture sources. Groundwater is primarily recharged by precipitation from the cold part of the hydrological year. It exhibits substantial attenuation of isotopic signals, which indicates extensive mixing processes but prevents quantitative estimation of mean residence time. Groundwater is predominantly recharged from elevations above 900 m a.s.l., with one spring showing evidence of higher-elevation recharge. Analysis confirms the system’s dual porosity: a rapid, conduit-dominated response indicates high vulnerability to surface contamination, while a sustained, matrix-dominated response provides greater buffering capacity. These findings highlight the vulnerability of karst systems to projected reductions in autumn precipitation, the critical recharge season, and demonstrate the necessity of multi-tracer approaches for comprehensive aquifer characterization. Full article

The transplanted cotton–wheat rotation enables dual cropping but alters root system architecture, typically suppressing taproot growth and promoting shallow lateral and fibrous roots, with unclear implications for irrigation response and water use efficiency (WUE). Field experiments were conducted in 2021 and 2022 to investigate root growth, spatial distribution, and water uptake sources, using a minirhizotron system and stable hydrogen and oxygen isotopes. The study examined the effects of two cultivation modes (direct seeding and transplanting) and three irrigation methods (border irrigation, micro-spray tape irrigation, and surface drip irrigation) on cotton root traits and WUE. Results showed that transplanted cotton roots were predominantly concentrated in the 0–30 cm soil layer (75.35–77.13% of total root length), significantly higher than those of direct-seeded cotton (63.10–74.71%). Under micro-spray tape and drip irrigation, the root length density (RLD) of transplanted cotton was 18.55% and 23.46% higher, respectively, than that of direct-seeded cotton, whereas under border irrigation it was 5.09% lower. Transplanted cotton mainly extracted water from the 0–40 cm soil layer (utilization rate: 65.49%), while direct-seeded cotton primarily relied on water from the 20–60 cm layer (53.20%). Although no statistically significant difference in yield was observed between the two cultivation modes, transplanted cotton exhibited a 15.37% higher WUE than direct-seeded cotton. Moreover, surface drip irrigation substantially enhanced WUE, exceeding that under border irrigation and micro-spray tape irrigation by 37.35% and 14.07%, respectively. This study enhances understanding of root traits in transplanted cotton and demonstrates that irrigation methods regulate WUE by modifying root distribution and water uptake patterns. Full article

Grapevine water relations are increasingly influenced by drought under climate change, with significant implications for yield, fruit composition and wine quality. Stable isotopes of hydrogen, oxygen, carbon and nitrogen (δ²H, δ¹⁸O, δ¹³C and δ¹⁵N) provide sensitive tracers of plant water sources and physiological responses to stress. Here, we combined dual water isotopes (δ²H, δ¹⁸O), carbon and nitrogen isotopes (δ¹³C, δ¹⁵N), and high-resolution micrometeorological/soil observations to diagnose drought dynamics in Vitis vinifera cv. Sauvignon blanc (Orlești, Romania; 2023–2024). Dual-isotope relationships delineated progressive evaporative enrichment along the soil–plant–atmosphere continuum, with slopes LMWL ≈ 6.41 > stem ≈ 5.0 > leaf ≈ 2.2, consistent with kinetic fractionation during transpiration (leaf) superimposed on source-water signals (stem). Weekly leaf δ¹⁸O covaried strongly with relative humidity (RH; r = −0.69) and evapotranspiration (ET; r = +0.56), confirming atmospheric control of short-term enrichment, while stem isotopes showed buffered responses to soil water. We integrated Δ¹⁸O (leaf–stem), RH, ET, and soil matric potential at 60 cm (Soil₆₀) into an Isotopic Drought Index (IDI), which captured the onset, intensity, and persistence of the July–August 2024 drought (IDI_0–100 > 90; RH < 60%, ET > 40 mm wk⁻¹, Soil₆₀ > 100 cb). Carbon and nitrogen isotopes provided complementary, integrative diagnostics: δ¹³C increased (less negative) with drought (r = −0.52 with RH; +0.49 with IDI), reflecting higher intrinsic water-use efficiency, whereas δ¹⁵N rose with soil dryness and IDI (leaf: r ≈ +0.48 with Soil₆₀; +0.42 with IDI), indicating constraints on N acquisition and enhanced internal remobilization. Together, multi-isotope and environmental data yield a mechanistic, field-validated framework linking atmospheric demand and edaphic limitation to vine physiological and biogeochemical responses and demonstrate the operational value of an isotope-informed drought index for precision viticulture. Full article

Background: Starvation represents a specific pathological entity characterized by severe nutritional deprivation leading to multi-organ failure. Despite its forensic relevance, a comprehensive synthesis of autopsy findings remains lacking. Methods: This systematic review was conducted in accordance with PRISMA 2020 guidelines. PubMed, Scopus, and Google Scholar were searched from inception to June 2025 using a pre-specified Boolean query. Eligible studies included case reports, case series and cohort investigations reporting post-mortem evidence of starvation or starvation-related malnutrition. Data extracted encompassed demographic, contextual, macroscopic, histological, and ancillary findings. Results: Fourteen studies were included, comprising 20 individual cases and two population-based cohorts (totaling 1647 deaths). Most cases (75%) involved children, predominantly victims of domestic neglect; adults accounted for 25%, mainly due to anorexia nervosa or voluntary fasting. Six cadavers were severely decomposed or mummified. Across studies, consistent autopsy findings included extreme emaciation, near-total loss of subcutaneous and visceral fat, empty gastrointestinal tract, and diffuse organ atrophy, especially of the liver, heart, thymus, and pancreas. Histology revealed hepatic steatosis, myocardial fibrosis, thymic involution and gelatinous transformation of adipose tissue. Ancillary methods (dual-energy X-ray absorptiometry, stable isotope and anthropological analyses) confirmed malnutrition in decomposed or skeletonized remains. Conclusions: This review delineates the morphological and histopathological hallmarks of starvation and suggests the possible diagnostic value of ancillary techniques in advanced decomposition. The predominance of neglect-related pediatric cases underscores starvation as a forensic indicator of social and caregiving failure. Establishing reproducible morphological and histological indicators may improve the consistency of forensic diagnosis and strengthen the evidentiary basis for determining starvation as a cause of death. Full article

Objectives: The impact of combining animal and plant protein sources on digestibility is unclear, despite their increasing clinical use. Using a non-invasive dual stable isotope tracer approach, we assessed the digestibility, bioavailability and utilization of distinct protein blends in older adults, and associated plasma amino acid profiles and muscle protein synthesis (MPS) rates. Methods: Thirty-two older men (69 ± 3 y) consumed one of four protein blends (A (51:49, casein/soy); B and C (35:25:20:20, whey/casein/soy/pea); D (80:20, casein/whey)) alongside primed constant infusions of [1,2-¹³C₂] leucine for 8 h. Arterialized blood and vastus lateralis muscle biopsies were collected during a trickle feed protocol with all blends providing 20 g total protein, universally labeled ¹³C-spirulina, and ²H-cell free amino acid mix to determine digestibility. This trial was registered at Clinicaltrials.gov (ID-NCT07038655). Results: No differences (¹³C:²H ratios) were found in digestibility between the protein blends (p > 0.05). Mean (±SEM) fed state MPS at 2.5 h was 0.078 ± 0.009%/h, 0.075 ± 0.012%/h, 0.085 ± 0.007%/h and 0.065 ± 0.011%/h for drinks A, B, C and D, respectively, with a main time effect observed (p < 0.01), but no significant differences between drinks. Plasma essential amino acids (EAAs) increased significantly from baseline for all blends by 40 min (p < 0.05), with no differences between blends at any time point. Conclusions: These findings suggest that protein quantity (and/or leucine content), rather than composition, appears to be the most important factor driving MPS. Future work should focus on clinical populations where protein requirements and digestibility characteristics may differ. Full article

Cadmium (Cd) pollution poses a serious threat to freshwater ecosystems. The freshwater mussel Anodonta woodiana is increasingly used as a bioindicator for monitoring Cd pollution in aquatic environments. However, the primary routes of Cd accumulation in A. woodiana remain unclear, and the molecular regulatory mechanisms underlying Cd accumulation are poorly understood. To address these gaps, this study employed a novel stable isotope dual-tracer technique to trace Cd from water (waterborne ¹¹²Cd) and the green alga Chlorella vulgaris (dietary ¹¹³Cd) during the simultaneous exposure experiment. Comparative transcriptomic analysis was then conducted to characterize molecular responses in A. woodiana following Cd exposure. The results showed that although newly accumulated ¹¹²Cd and ¹¹³Cd increased with exposure concentration and duration, the relative importance of ¹¹²Cd (91.6 ± 2.8%) was significantly higher than that of ¹¹³Cd (8.4 ± 2.8%) (p < 0.05). Cd exposure induced differentially expressed genes primarily enriched in the metabolic processes, cellular processes, and/or the ubiquitin-mediated proteolysis pathway. Within the ubiquitin-mediated proteolysis pathway, TRIP12 (E3 ubiquitin-protein ligase TRIP12) and Cul5 (cullin-5) were significantly upregulated. The findings will provide critical insights for interpreting Cd biomonitoring data in freshwater environments using mussels as bioindicators. Full article

The fluid action mechanism and diagenetic evolution of tuff reservoirs in the Cretaceous Huoshiling Formation of the Dehui fault depression are discussed herein. The fluid properties of the diagenetic flow are defined, and the pore formation mechanism of the reservoir space is explained by means of thin sections, X-ray diffraction, electron probes, scanning electron microscopy (SEM), cathodoluminescence, and stable carbon and oxygen isotopic composition and fluid inclusion tests. The results reveal that the tuff reservoir of the Huoshiling Formation is moderately acidic, and the physical properties of the reservoir are characterized by middle to high porosity and ultralow permeability. The pore types are complex, comprising both primary porosity and secondary porosity, with dissolution pores and devitrification pores being the most dominant. Mechanical compaction and cementation are identified as key factors reducing reservoir porosity and permeability, while dissolution and devitrification processes improve pore structure and enhance pore connectivity. Diagenetic fluids encompass alkaline fluids, acidic fluids, deep-seated CO₊-rich hydrothermal fluids, and hydrocarbon-associated fluids. These fluids exhibit dual roles in reservoir evolution: acidic fluids enhance the dissolution of feldspar, tuffaceous materials, and carbonate minerals to generate secondary pores and improve reservoir quality, whereas alkaline fluids induce carbonate cementation, and clay mineral growth (e.g., illite) coupled with late-stage mineral precipitation obstructs pore throats, reducing permeability. The interplay among multiple fluid types and their varying dominance at different burial depths collectively governs reservoir evolution. This study underscores the critical role of fluid–rock interactions in controlling porosity–permeability evolution within tuff reservoirs. Full article

In this paper, we revisit the Mesolithic–Neolithic transition in western Scotland and the links between early European farmers and middens in light of new aDNA, radiocarbon, and stable isotopic evidence. New carbon and nitrogen stable isotopic data for food sources (plant and animal remains) from a Mesolithic site are presented, and dietary FRUITS models are recalculated based on these data. We also respond to recent criticisms of the Bayesian approach to diet reconstruction. Results support the view that Neolithic people had at most a minimal contribution of marine foods in their diet and also point to a dual population model of transition in western Scotland. A significant aspect of the transition in coastal western Scotland is the co-occurrence of Neolithic human remains with shell-midden deposits, which appears to contradict stable isotopic evidence indicating a minimal contribution of marine resources to the diet of early farming communities in the region. Finally, we highlight the need for further research to fully address these issues, including (1) targeted isotopic analyses of potential plant and animal resources, (2) single-entity radiocarbon and ZooMS analyses of animal bones and artefacts from shell middens, and (3) further aDNA analyses of the remains of Late Mesolithic and Neolithic people. Full article

The source of sulfate in the groundwater of karst springs in the northern Taihang Mountains remains unclear due to the influence of multiple factors. To investigate this, 33 sampling points were selected in August 2022 across the exposed, covered, and buried areas of the spring basin, and water samples were collected. Hydrochemistry and sulfur–oxygen dual isotope methods were employed to examine the distribution characteristics of sulfate, δ¹⁸O_SO4, and δ³⁴S_SO4. Based on the distinct characteristics of sulfur isotopes from different sources, the sources of sulfate in various environments were qualitatively analyzed. Additionally, the contribution rates of each source were quantitatively determined using a Bayesian stable isotope mixing model. The results showed that the sulfate content in karst groundwater ranged from 16.68 to 156.84 mg/L, with an average of 62.22 mg/L, and indicated an increasing trend from exposed to covered to buried areas. The δ³⁴S_SO4 values in karst groundwater ranged from 3.1‰ to 13.5‰, with an average of 6.49‰, while the δ¹⁸O_SO4 values ranged from 2.9‰ to 10.3‰, with an average of 5.49‰. The δ³⁴S_SO4 values showed a general increasing trend across the exposed, covered, and buried areas, whereas the δ¹⁸O_SO4 values remained relatively stable across these areas. The analysis revealed that the primary sulfate sources in the exposed area were atmospheric precipitation, soil sulfate, chemical fertilizer, and sewage, contributing 19.6%, 63.5%, 9.4%, and 7.5%, respectively. In the covered area, the main sources were atmospheric precipitation, sulfide oxidation, soil sulfate, and gypsum dissolution, with contributions of 16.5%, 58.7%, 15.9%, and 8.9%, respectively. In the buried area, the sulfate primary originated from atmospheric precipitation, sulfide oxidation, and gypsum dissolution, contributing 11.6%, 78.5%, and 9.9%, respectively. This study provides critical insights into the sulfate sources in different environments, enhancing the understanding of groundwater sulfate pollution in the study area. These findings provide a scientific foundation for managing groundwater pollutants and resources in the karst regions of northern China. Full article

Hydrothermal activity is widespread in sedimentary basins, but its dual effects (chemistry and temperature) on shale reservoirs are rarely discussed. In this research, we systematically collected 33 well core samples from Q1 to Q9 units in Gulong Sag, Songliao Basin, and analyzed them using a variety of analytical techniques, including a field emission scanning electron microscopy (FE-SEM), an energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), and stable C-O isotopes. Combined with the collected vitrinite reflectance (Ro), total organic carbon (TOC), and soluble hydrocarbon content data, which is the sum of free oil (pyrolysis S1) and sorb oil content (pyrolysis S2), the results show that (1) Q4 and Q8 units have large amounts of hydrothermal minerals, and its C-O isotope obviously shifts to negative, which implied those units are the main hydrothermal fluid influence area; (2) the hydrothermal activity occurred in the late depositional period of Q1–Q9 units such that its geochemistry has little effect on the proliferation of algae blooms, but its high temperature calculated by δ¹⁸O temperature formulas (around 208 °C) promoted the organic matter maturation process around Q4 and Q8; and (3) the overpressure caused by hydrothermal activity protected the shale reservoir and minimized the decrease in mineral reservoir brittleness index caused by hydrothermal fluid influence. We suggest that the shale reservoir affected by hydrothermal fluid will become a good geology “dessert”, and its upper and/or lower bounds can form an engineering “dessert” due to the precipitation of large amounts of brittle carbonate minerals. Full article

To bridge the gap between lab-scale microcosm research and field application in the compound-specific stable isotope analysis (CSIA) of atrazine, we studied the characteristics of carbon and nitrogen isotope fractionation in the atrazine degradation processes within a constructed wetland. In the wetland, we observed multiple element (C, N) isotope fractionation parameters, such as kinetic isotope effects and dual isotope slopes. These parameters are very consistent with those observed in the cultivation of AtzA- or TrzN-harboring strains, suggesting a similarity in the pathway and reaction mechanism of atrazine biodegradation between the two settings. However, we recorded variable carbon (${\epsilon }_C:$−3.2 ± 0.6‰ to −4.3 ± 0.6‰) and nitrogen isotope fractionation (${\epsilon }_N:$1.0 ± 0.3‰ to 2.2 ± 0.3‰) across different phases. This variance could lead to an over- or underestimation of the biodegradation extent of atrazine when employing the large or small enrichment factor of the carbon isotope. Intriguingly, the estimation accuracy improved considerably when using the enrichment factor (−4.6‰) derived from the batch cultivation of the pore water. This study advances the application of CSIA in tracking atrazine biodegradation processes in ecosystems, and it also underlines the importance of the careful selection and application of the enrichment factor in quantifying the intrinsic biodegradation of atrazine in ecosystems. Full article

Biogas production from waste materials has emerged as a promising avenue for sustainable energy generation, offering a dual benefit of waste management and renewable energy production. The selection and preparation of waste feedstocks, including agricultural residues, food waste, animal manure, and municipal solid wastes, are important for this process, while the microbial communities are majorly responsible for bioconversions. This review explores the role of complex microbial communities and their functions responsible for the anaerobic digestion of wastes. It covers the crucial physiological processes including hydrolysis, acidogenesis, acetogenesis, and methanogenesis, elucidating the microbial activities and metabolic pathways involved in the prospects of improving the efficiency of biogas production. This article further discusses the influence of recent progress in molecular techniques, including genomics, metagenomics, meta-transcriptomics, and stable isotope probing. These advancements have greatly improved our understanding of microbial communities and their capabilities of biogas production from waste materials. The integration of these techniques with process monitoring and control strategies has been elaborated to offer possibilities for optimizing biogas production and ensuring process stability. Microbial additives, co-digestion of diverse feedstocks, and process optimization through microbial community engineering have been discussed as effective approaches to enhance the efficiency of biogas production. This review also outlines the emerging trends and future prospects in microbial-based biogas production, including the utilization of synthetic biology tools for engineering novel microbial strains and consortia, harnessing microbiomes from extreme environments, and integrating biogas production with other biotechnological processes. While there are several reviews regarding the technical aspects of biogas production, this article stands out by offering up-to-date insights and recommendations for leveraging the potential of microbial communities, and their physiological roles for efficient biogas production. These insights emphasize the pivotal role of microbes in enhancing biogas production, ultimately contributing to the advancement of a sustainable and carbon-neutral future. Full article