Association between serum albumin creatinine ratio and all-cause mortality in intensive care unit patients with heart failure.

Background: The serum albumin creatinine ratio (sACR) has been established as a potential indicator for heart disease, however, its relationship with prognosis in intensive care unit (ICU) patients with heart failure remains uncertain. This study aimed to investigate the association between sACR levels and all-cause mortality ICU patients with heart failure. Methods: Clinical data from MIMIC-Ⅳ database was utilized for the analysis of ICU patients with heart failure. Patients were categorized into quartiles (Q1-Q4) based on sACR levels. Kaplan-Meier survival analysis and multivariate adjusted Cox regression models were employed to assess the association between sACR levels and mortality outcomes within 365 days. Subgroup analysis was used to evaluate the prognostic impact of sACR across diverse populations. Restricted cubic spline curves and threshold effect analysis were utilized to quantify the dose-response relationship between sACR levels and risk of all-cause mortality. Mediating effects analysis was conducted to present the involvement of albumin and creatinine in the association between sACR and outcomes. Results: The analysis encompassed a cohort of 4,506 patients, with Kaplan-Meier curves indicating that individuals with lower sACR levels exhibited an elevated risk of all-cause mortality (log-rank p < 0.001). Multivariate adjusted Cox regression and subgroup analysis demonstrated that individuals in Q2 [hazard ratio (HR) 0.82, 95%CI 0.71∼0.96], Q3 (HR 0.76, 95%CI 0.64∼0.91) and Q4 (HR 0.62, 95%CI 0.50∼0.76) had a decreased risk of mortality compared to individuals in Q1 (lower levels of sACR) (p for trend < 0.001), and this inverse relationship was consistently observed across various subgroups. Subsequent restricted cubic spline analysis revealed a negative yet nonlinear relationship between sACR and all-cause mortality (p for nonlinear < 0.001), and threshold effect analysis indicated an effect threshold of 3.75. Additionally, mediating effects analysis emphasized that sACR influenced the outcome not only through serum albumin and creatinine pathways, but also through direct mechanisms. Conclusion: The study found that low levels of sACR were independently associated with an increased risk of one-year all-cause mortality in ICU patients with heart failure, with a threshold effect, which could potentially serve as an early warning indicator for high-risk populations.

Lithium and brine geochemistry in the Qianjiang Formation of the Jianghan Basin, central China.

The Li-enriched oilfield brine is a very important lithium resource. It has gained much attention and become the target of active Li surveys with the growing global demand for Li. However, only little is known about their feature and nature. In the study, hydrochemical data from 155 oil wells tapping the Eocene to Lower Oligocene Qianjiang Formation of the Jianghan Basin, central China indicate that the brines are of the Na-Cl or Na-Ca-Cl type and are characterized by highly variable Li contents of 7.56 to 150 mg/L, with Mg/Li ratios less than 11.65. High Na/Cl and Cl/Br molar ratios indicate distinct contributions from halite dissolution. The Ca excess, Na deficit and Ca/Mg and Ca/Sr molar ratios in the brines imply multiple diagenetic processes, including halite dissolution, dolomitization, albitization and calcite or anhydrite cementation. The lithium contents of these brines have a weak relationship with the salinity and a negative correlation with Cl/Br ratios, possibly indicating that these Qianjiang oilfield brines have been diluted by secondary brines derived from halite dissolution. The spatial distribution patterns for Li and B concentrations of the brines are different from those for salinity and Br contents and show a geographic pattern, indicating that Li enrichment in the Qianjiang brines is likely connected with geothermal sources associated with volcanic activity.

Major and trace-element geochemistry of Late Cretaceous clastic rocks in the Jitai Basin, southeast China.

Major, trace and rare earth element (REE) geochemistry of the late Cretaceous lower Zhoutian Formation from the Jitai Basin of Southeast China were measured by inductively coupled plasma mass spectrometry (ICP-MS) analysis to infer the provenance of the sediments and to reconstruct the palaeoenvironment and palaeoclimate. The wide range of Sr/Cu ratios point to a fluctuating palaeoclimate, and the negative correlation between the FeO/MnO and Al2O3/MgO ratios and the Sr/Cu ratio indicates that the late Cretaceous climate during the lower Zhoutian Formation in the Jitai Basin can be divided into two parts. The lower part experienced two cooling periods, whilst the upper part was dominated by warm-humid climate. Mostly corresponding trends of the B/Ga, Sr/Ba and Sr/Cu ratios show that the salinity changed consistently with the late Cretaceous climate during the lower Zhoutian Formation in the Jitai Basin. During the lower part, the salinity changed from salt water to fresh/brackish water. In the upper part, water was mainly fresh/brackish, and there were many changes from fresh/brackish water to salt water. The relatively stable Ni/Co, V/Cr, V/(V + Ni) and Ce/Ce* data indicate a long period of oxic conditions. The La-Th-Sc, Th-Sc-Zr/10 and La/Th-Hf data of the silt- and sandstones of the lower Zhoutian Formation show that its provenance was mainly a mixture of felsic upper crust sediments and older sedimentary rocks.

Micron-Nanometer Evaporite Mineral Compositions in the Jiangling Depression, Jianghan Basin, China, by Means of Scanning Electron Microscopy.

Scanning electron microscopy (SEM) was used to analyze and study micron-nanometer evaporite samples collected from Paleocene and Eocene drill cores in the Jiangling Depression. Accordingly, seven beds of potassium-bearing solid rocks were accurately identified. Sylvite, carnallite, syngenite, dolomite, thenardite, anhydrite, glauberite, halite, barite, celestite, and other solid salt minerals were found, and carnallite, syngenite, and thenardite were found for the first time in the Jiangling Depression. Sylvite, syngenite, and carnallite indicate that the Paleogene salt lakes in the Jiangling Depression had evolved to the sylvite stage and that prospecting for solid sylvite would be satisfactory. Micron-nanometer celestite is contained in the evaporites, from which we can infer that strontium may have been provided by deep formation water (or oil-field water). This finding is of great significance to studying the genesis of sylvite sediment in the Jiangling Depression. From the extensive development of primary glauberite beds typical of warm salt minerals in the Shashi Formation, it can be inferred that the late Paleogene paleoclimate in the Jiangling Depression of the Jianghan Basin was dry and hot. Based on the extensive distribution of micron-nanometer pyrite, siderite, iron and Fe2O3/FeO ratios in evaporite sediments and color analysis of mudstones, the evaporites in the study area formed in an underwater anoxic, reducing environment during sedimentation. Therefore, the evaporite sediments in the Paleocene-Eocene interval of the Jiangling Depression are proposed to have formed in a saltwater lake sedimentary environment, and the ancient lake was characterized by a deep-water salt lake sedimentary model.

Oscillation of mineral compositions in Core SG-1b, western Qaidam Basin, NE Tibetan Plateau.

Uplift of the Tibetan Plateau since the Late Miocene has greatly affected the nature of sediments deposited in the Qaidam Basin. However, due to the scarcity of continuously dated sediment records, we know little about how minerals responded to this uplift. In order to understand this response, we here present results from the high-resolution mineral profile from a borehole (7.3-1.6 Ma) in the Basin, which shows systematic oscillations of various evaporite and clay minerals that can be linked to the variation of regional climate and tectonic history. In particular, x-ray diffraction (XRD) analyses show that carbonate minerals consist mainly of calcite and aragonite, with minor ankerite and dolomite. Evaporates consist of gypsum, celesite and halite. Clay minerals are principally Fe-Mg illite, mixed layers of illite/smectite and chlorite, with minor kaolinite and smectite. Following implications can be drawn from the oscillations of these minerals phases: (a) the paleolake was brackish with high salinity after 7.3 Ma, while an abrupt change in the chemical composition of paleolake water (e.g. Mg/Ca ratio, SO4(2-) concentration, salinity) occurred at 3.3 Ma; (b) the three changes at ~6.0 Ma, 4.5-4.1 Ma and 3.3 Ma were in response to rapid erosions/uplift of the basin;

Microbial Habitability and Pleistocene Aridification of the Asian Interior.

UNLABELLED: Fluid inclusions trapped in ancient halite can contain a community of halophilic prokaryotes and eukaryotes that inhabited the surface brines from which the halite formed. Long-term survival of bacteria and archaea and preservation of DNA have been reported from halite, but little is known about the distribution of microbes in buried evaporites. Here we report the discovery of prokaryotes and single-celled algae in fluid inclusions in Pleistocene halite, up to 2.26 Ma in age, from the Qaidam Basin, China. We show that water activity (aw), a measure of water availability and an environmental control on biological habitability in surface brines, is also related to microbe entrapment in fluid inclusions. The aw of Qaidam Basin brines progressively decreased over the last ∼1 million years, driven by aridification of the Asian interior, which led to decreased precipitation and water inflow and heightened evaporation rates. These changes in water balance produced highly concentrated brines, which reduced the habitability of surface lakes and decreased the number of microbes trapped in halite. By 0.13 Ma, the aw of surface brines approached the limits tolerated by halophilic prokaryotes and algae. These results show the response of microbial ecosystems to climate change in an extreme environment, which will guide future studies exploring deep life on Earth and elsewhere in the Solar System. KEY WORDS: Halite fluid inclusions-Ancient microbes-Water activity-Qaidam Basin-Pleistocene aridification. Astrobiology 16, 379-388.