•Carbonate clumped isotopes validate the preservation of primary carbonate of the Gonjo Basin in the early and middle Eocene.•The Gonjo Basin was low (0.7 km) in the early Eocene and rose to 3.8 km ...in the middle Eocene.•Rapid uplift was induced by intracontinental subduction between the Lhasa and Qiangtang terrains.
Views differ on the uplift history of the SE Tibetan Plateau and causal geodynamic mechanisms, yet reliable age-constrained paleoaltimetry in this region could test growth models of the entire plateau. Here we apply carbonate clumped isotope thermometry to well-dated carbonate paleosols and marls in the Gonjo Basin, SE Tibet, to reveal the topographic evolution of the basin. The sedimentary ages of carbonates of the lower and upper Ranmugou Formation are constrained to 54-50 Ma and 44-40 Ma, respectively. The temperature derived from carbonate clumped isotope thermometry indicates the mean annual air temperature (MAAT) of the Gonjo Basin in the early Eocene was ∼24°C, which is consistent with the warm climate indicated by palm fossils. The MAAT of the basin in the middle Eocene was ∼7°C, 17°C cooler than in the early Eocene. Carbonate clumped oxygen isotope thermometry-based paleoaltimetry shows the Gonjo Basin experienced a rapid uplift of 3.1 km, from ∼0.7 km in the early Eocene to ∼3.8 km in the middle Eocene. This rise explains the marked cooling. As a cause of this rapid rise, and the associated regional climate change transforming the landscape from desert to forest, we invoke crustal deformation and thickening induced by intracontinental subduction between the Lhasa and Qiangtang terranes that comprise the core of the Tibet.
Measurements of stable water isotopes (oxygen and hydrogen) are commonly used to estimate palaeoelevation and quantify past changes in surface height across Tibet. Isotope palaeoaltimetry is often ...based on simple Rayleigh fractionation of a “parcel of air”, but must make a considerable number of approximations and assumptions. In this paper, we elaborate on the practicability of oxygen water isotopes in palaeoaltimetry, and evaluate a recent challenge to the palaeoaltimetry community. First, we examine the isotopic composition of oxygen (δ18O) versus altitude relationship in a set of five topographic realisations of Tibet using an isotope-enabled palaeoclimate model for the mid-Eocene, a period where a variety of topographic ‘uplift’ models have been proposed, and compare it to modern relationships. Second, we investigate whether isotopic composition is a good predictor of more modest changes in topography, such as the introduction of a valley system or uplift of only part of the Tibetan region. The aim of the paper is not to perform a direct comparison to data, but to use the model to further refine knowledge of the strengths and limitations of using oxygen isotopes in palaeoaltimetry. We find that oxygen isotope palaeoaltimetry works surprisingly well, with the exception that it could not identify low elevation valley systems bounded by high elevations because the isotopic composition of the water in the air becomes depleted at the first high elevation that an air parcel passes over and does not recover when it descends into the valley. Hence, isotope-based elevations are biased towards mountain range peaks. Overall, the application of oxygen isotope palaeoaltimetry does have value, but would be further strengthened when employed together with isotope-enabled models. In conjunction with other techniques such as terrestrial thermal lapse rates and energy conservation approaches, over a wide spatial region, a more accurate and fully three-dimension view of complex palaeo-topography is increasingly possible, which will in turn improve the precision of these palaeoaltimeters.
•Isotope enabled paleoclimate models can aide paleoaltimetry studies.•Water isotope paleoaltimetry can accurately reproduce mountain height.•Accurate reconstructions of complex topography are more challenging.•Airmasses modification along the elevation trajectory can bias the height estimate.
Abstract
Objective
Surgical site infection(SSI)after neurosurgical procedure can be devastating. Delayed hospital stay has been identified as a potentially modifiable driver of SSI in general surgery ...patients. However, the relationship between preoperative length of stay and SSI has not been quantified previously in neurosurgery. This study aimed to clarify the association.
Design
A Cohort study based on STROBE checklist.
Method
This observational study focused on cranial neurosurgery patients at a tertiary referral centers in China. Data collection from hospital information system conducted between 1 January 2016 and 31 December 2016 was used to examine the results of interest (n = 600). Logistic regression analysis explored association between preoperative length of stay and SSI, adjusting for potential confounders.
Results
Overall SSI prevalence was 10.8% and was significantly higher in the longer preoperative length of stay group. Besides preoperative length of stay, American Society of Anesthesiologists score, type of surgery, gross blood loss also significantly associated with SSI prevalence. Compared with 1 to 2 days, longer preoperative length of stay was associated with increased SSI prevalence after adjustment for confounders (3 to 4 days: odds ratioOR, 0.97595%CI, 0.417 to 2.281; 5 to 6 days: OR, 2.83095%CI, 1.092 to 7.332; 7 or more days: OR, 4.03995%CI, 1.164 to 14.015; P for trend < 0.001). On the other hand, we found a positive association between preoperative length of stay to deep/space-organ SSI (OR = 1.404; 95% CI: 1.148 to 1.717; P for trend < 0.001), which was higher than superficial SSI (OR = 1.242; 95% CI: 0.835 to1.848; P for trend= 0.062).
Conclusions
In a cohort of patients from a single center retrospective surgical registry, a longer preoperative length of stay was associated with a higher incidence of cranial neurosurgical SSI. There is room for improvement in preoperative length of stay. This can be used for hospital management and to stratify patients with regard to SSI risk.
•The West Burma Block experienced a significant clockwise rotation of 38.3°±6.9°since 64.4 Ma.•The West Burma Block experienced a counterclockwise rotation of 14.6 ± 4.2°since 26.6 Ma.•Results ...endorsed lateral extrusion model which predicts escape tectonics developed in SE Asia in Cenozoic.
The magnitude and timing of deformation in the form of vertical-axis rotation in the eastern Tibetan Plateau and Southeast Asia during the Cenozoic period are the key to understanding the India-Asia collision and subsequent geological processes. Our new paleomagnetic and geochronological data from Myanmar show that the characteristic remanent magnetization (ChRM) mean directions of sedimentary tuffaceous layers (31 effective specimens) and rhyolites (11 paleomagnetic site-mean directions), which formed at ∼64.4 Ma and ∼26.6 Ma, were D±ΔD/I±ΔI = 50.8°±11.0°/33.1°±9.2° with α95 = 9.2° and D±ΔD/I±ΔI = 356.8°±6.5°/16.9°±6.2° with α95 = 6.2°, respectively. These data indicate that the West Burma Block (WBB) has experienced a significant clockwise rotation of 38.3°±6.9° since ∼64.4 Ma and a later counterclockwise rotation of 14.6 ± 4.2° since ∼26.6 Ma with respect to stable Asia. The clockwise rotation of ∼40° of the WBB since 64.4 Ma (early Paleocene) with respect to stable Asia is attributable to the India-Asia collision, and the later counterclockwise rotation of 14.6°±4.2° since 26.6 Ma (late Oligocene) is attributable to the dextral-slip faulting activity of the Sagaing Fault. These paleomagnetic analyses, combined with previously published geological research in SE Asia, are substantially consistent with the predictions of the extrusion model for the SE Asia realm.
Abstract
The main rivers that originate from the Tibetan Plateau are important as a resource and for the sedimentary and biogeochemical exchange between mountains and oceans. However, the dominant ...mechanism for the evolution of eastern Tibetan river systems remains ambiguous. Here we conduct geomorphological analyses of river systems and assess catchment-average erosion rates in the eastern Tibetan Plateau using a digital elevation model and cosmogenic radionuclide data. We find that major dividing ranges have northeast oriented asymmetric geometries and that erosion rates reduce in the same direction. This coincides with the northeastward indentation of India and we suggest this indicates a primarily tectonic influence on the large-scale configuration of eastern Tibetan river systems. In contrast, low-level streams appear to be controlled by fluvial self-organization processes. We propose that this distinction between high- and low-order channel evolution highlights the importance of local optimization of optimal channel network models in tectonically active areas.
Background Kurarinone, a compound derived from Sophora flavescens, has been widely studied for its anti-inflammatory properties, as well as its potential in treating autoimmune encephalomyelitis and ...inflammation-related musculoskeletal diseases. However, the specific molecular mechanisms by which Kurarinone affects osteoporosis are still not fully understood. Objectives To explore the potential pharmacological targets and molecular mechanisms underlying the therapeutic effects of Kurarinone on osteoporosis. Materials and Methods To confirm the impact of Kurarinone on osteoporosis, network pharmacology techniques were used to analyze the mechanisms of Kurarinone on osteoporosis. Molecular docking was performed to examine the binding of Kurarinone to key targets involved in osteoporosis. Then, we conducted TRAcP staining, quantitative polymerase chain reaction (q-PCR), and Western blot experiments to validate the results. Results Utilizing network pharmacology approaches coupled with docking analysis, our investigation revealed that Kurarinone was involved in the osteoclast differentiation and MAPK signaling pathways. According to in vitro experiments, Kurarinone was found to inhibit osteoclast formation through the p38/MAPK pathway. Conclusion This study suggests that Kurarinone may treat osteoporosis by inhibiting MAPK phosphorylation and inhibiting osteoclast formation.
Background
Osteoporosis (OP) and type 2 diabetes (T2D) are commonly encountered metabolic disorders in clinical practice, but the comorbidity mechanism has not been clarified. This study explored the ...underlying mechanisms for utilizing bioinformatics methods. Furthermore, it predicted traditional Chinese medicines (TCMs) with preventive and therapeutic effects.
Materials and Methods
GSE35958 and GSE43950 were retrieved and downloaded from the GEO database, and differential expression analysis was performed to identify differentially expressed genes (DEGs) with similar expression patterns in OP and T2D. Then, the common DEGs were uploaded to the STRING database to construct a protein interaction network. Enrichment analysis of the screened genes was conducted using R language packages. Relevant TCMs were searched and screened based on gene targets using the Encyclopedia of traditional Chinese medicine (ETCM) database. Molecular docking of active ingredients of the TCMs and related gene targets was performed using AutoDock Vina software.
Results
By analyzing the gene expression microarrays, GSE35958 and GSE43950, 34 genes with the same expression pattern shared by OP and T2D were identified. Among these genes, 32 were upregulated and two were downregulated. Protein interaction network analysis revealed that tumor necrosis factor, vascular endothelial growth factor A, and CD44 might play key roles in the co-pathogenesis of T2D and OP. TCMs, including Wolfberry (枸杞), Ginseng (人参), and Yam (山药), were screened based on key genes. Molecular docking results demonstrated binding activity between all active ingredients and the related gene targets.
Conclusion
This study explored the potential molecular co-pathogenesis of OP and T2D through bioinformatic analysis and preliminarily predicted traditional herbal medicines that may have preventive and therapeutic effects.
Abstract The mid-Piacenzian Warm Period (MPWP, ~ 3.264–3.025 Ma) is the most recent example of a persistently warmer climate in equilibrium with atmospheric CO 2 concentrations similar to today. ...Towards studying patterns and dynamics of a warming climate the MPWP is often compared to today. Following the Pliocene Model Intercomparison Project, Phase 2 (PlioMIP2) protocol we prepare a water isotope-enabled Community Earth System Model (iCESM1.2) simulation that is warmer and wetter than the PlioMIP2 multi-model ensemble (MME). While our simulation resembles PlioMIP2 MME in many aspects we find added insights. (1) Considerable warmth at high latitudes exceeds previous simulations. Polar amplification (PA) is comparable to proxies, enabled by iCESM1.2’s high climate sensitivity and a distinct method of ocean initialization. (2) Major driver of warmth is the downward component of clear-sky surface long-wave radiation ( $$\varDelta T_{\text{rlds}\_\text{clearsky}}$$ Δ T rlds _ clearsky ). (3) In iCESM1.2 modulated dominance of dynamic (δDY) processes causes different low-latitude (~ 30 S°–10°N) precipitation response than the PlioMIP2 MME, where thermodynamic processes (δTH) dominate. (4) Modulated local condensation leads to lower δ18O p across tropical Indian Ocean and surrounding Asian-African-Australian monsoon regions. (5) We find contrasting changes in tropical atmospheric circulations (Hadley and Walker cells). Anomalous regional meridional (zonal) circulation, forced by changes in tropical-subtropical (tropical) diabatic processes, presents a more comprehensive perspective than explaining weakened and expanded Hadley circulation (strengthened and westward-shifted Walker circulation) via static stability. (6) Enhanced Atlantic meridional overturning circulation owes to a closed Bering Strait.
Reconstructing the Paleogene topography and climate of central Tibet informs understanding of collisional tectonic mechanisms and their links to climate and biodiversity. Radiometric dates of ...volcanic/sedimentary rocks and paleotemperatures based on clumped isotopes within ancient soil carbonate nodules from the Lunpola Basin, part of an east-west trending band of basins in central Tibet and now at 4.7 km, suggest that the basin rose from <2.0 km at 50 to 38 million years (Ma) to >4.0 km by 29 Ma. The height change is quantified using the rates at which wet-bulb temperatures (
) decline at land surfaces as those surface rise. In this case,
fell from ~8°C at ~38 Ma to ~1°C at 29 Ma, suggesting at least ~2.0 km of surface uplift in ~10 Ma under warm Eocene to Oligocene conditions. These results confirm that a Paleogene Central Tibetan Valley transformed to a plateau before the Neogene.
PDF
