Search

Twenty taxa of fossil plants are described from the Sangonghe Formation (Lower Jurassic) of the Haojiagou section in the Junggar Basin, Xinjiang, NW China. The Sangonghe flora consists of Equisetales, ferns, bennettitaleans, ginkgoes, conifers and gnetales, but is dominated by ferns. It is a low species diversity but extraordinary flora for having a high proportion (45%) of thermophilous or arid-tolerant (xerophilous) elements, by comparing with 0% in the underlying Badaowan Formation and around 2% in the overlying Xishanyao Formation. These thermophilous or arid-tolerant (xerophilous) elements include Marattiopsis asiatica Kawasaki, Phlebopteris polypodioides Brongniart and Dictyophyllum sp. (ferns) , Otozamites leckenbyi Harris, Otozamites sp. , Zamites sp. and Dictyozamites sp. (bennettitaleans), Brachyphyllum ( Hirmeriella ?) sp. (conifers) and Cadmisega ephedroides Krassilov et Bugdaeva (gnetales). Based on the geological ranges of the known species and comparisons with the coeval floras in Eurasia, the age of the Sangonghe flora is Toarcian of the Early Jurassic. The flora reveals a climatic warming and aridification event, which occurred during the Toarcian in the Junggar Basin. Palaeontological (including palaeobotanical and palynological), sedimentological and geochemical data demonstrate that warming and aridification occurred widely across the north of China during the Toarcian, and this might be the response of the terrestrial ecosystem to the Toarcian Oceanic Anoxic Event (T-OAE).

Hypothermia preconditioning (HPC) improves cardiac function after cardiac arrest, yet the mechanism is unclear. We hypothesized that HPC-activated adenosine monophosphate-activated protein kinase (AMPK) activity may be involved. Adult male Wistar rats were randomly divided into normothermia Control, HPC (cooling to 32–34°C for 30 min), and HPC + Compound C (Compound C 10 mg/kg was injected intraperitoneally 30 min before HPC group). The rats underwent 7 min of untreated ventricular fibrillation (VF) followed by cardiopulmonary resuscitation (CPR). Cardiac function and hemodynamic parameters were evaluated at 4 h after return of spontaneous circulation (ROSC). Survival status was determined 72 h after ROSC. Mechanistically, we further examined the AMPK-Unc-51 Like Autophagy Activating Kinase 1 (ULK1)-mitophagy pathway and autophagic flux in vivo and in vitro. Six of twelve rats in the Control group, 10 of 12 rats in the HPC group, and 7 of 12 rats in HPC + Compound C group were successfully resuscitated. The 72-h survival rates were 1 of 12 Control, 6 of 12 HPC, and 2 of 12 HPC + Compound C rats, respectively ( P = 0.043). Rats in the HPC group demonstrated greater cardiac contractility and hemodynamic stability which were compromised by Compound C. Furthermore, HPC increased the protein levels of p-AMPKα and p-ULK1 and promoted the expression of mitochondrial autophagy-related genes. Compound C decreased the expression of mitochondrial autophagy-related genes and reduced autophagic flux. Consistent with the observations obtained in vivo, in vitro experiments in cultured neonatal rat cardiomyocytes (CMs) demonstrated that HPC attenuated simulated ischemia–reperfusion-induced CM death, accompanied by increased AMPK-ULK1-mitophagy pathway activity. These findings suggest that AMPK-ULK1-mitophagy pathway was activated by HPC and has a crucial role in cardioprotection during cardiac arrest. Manipulation of mitophagy by hypothermia may merit further investigation as a novel strategy to prevent cardiac ischemia–reperfusion injury.

Background Adverse left ventricular remodeling after myocardial infarction (MI) compromises cardiac function and increases heart failure risk. Till now, comprehension of the role transcription factor EB (TFEB) plays after MI is limited.ObjectivesThe purpose of this study was to describe the effects of TFEB on cell death and fibroblast differentiation after MI.MethodsAAV9 mediated up- and down-regulated TFEB expressions were generated in C57BL/6 mice two weeks before the MI modeling. Echocardiography, Masson, HE, Sirius red staining immunofluorescence, and wheat germ agglutinin staining were performed at 3 days, and 1, 2, and 4 weeks after MI modeling. Fibroblasts and myocytes collected from SD neonatal rats were transfected by adenovirus and siRNA, and cell counting kit-8 (CCK8), Cell Proliferation EdU Image (EDU), immunofluorescence, and Transwell assay were conducted. Myocardial fibrosis-related proteins and autophagy-related protein were identified by Western blot.ResultsThe up-regulation of TFEB resulted in reduced myocardial cell death, delayed fibroblasts proliferation and its differentiation into myofibroblasts, and up-regulated expression of LC3B three days after MI. Similar results were observed in vitro studies. Meanwhile, a significant up-regulation of EF, decrease in the ratio of the infarction length, and decreased protein level of collagen III were observed four weeks after MI modeling. The over-expression of TFEB slowed down myofibroblast migration and resulted in a significant down-regulation of collagen I level in myofibroblasts.ConclusionsTFEB demonstrated potential in improving cell death after MI by mediating autophagy and regulating fibroblast proliferation and transformation. Its molecular impacting mechanism deems further investigation.

Substantial morbidity and mortality are associated with postcardiac arrest brain injury (PCABI). MicroRNAs(miRNAs) are essential regulators of neuronal metabolism processes and have been shown to contribute to alleviated neurological injury after cardiac arrest. In this study, we identified miRNAs related to the prognosis of patients with neurological dysfunction after cardiopulmonary resuscitation based on data obtained from the Gene Expression Omnibus (GEO) database. Then, we explored the effects of miR-483-5p on mitochondrial biogenesis, mitochondrial-dependent apoptosis, and oxidative stress levels after ischemia‒reperfusion injury in vitro and in vivo. MiR-483-5p was downregulated in PC12 cells and hippocampal samples compared with that in normal group cells and hippocampi. Overexpression of miR-483-5p increased the viability of PC12 cells after ischemia‒reperfusion injury and reduced the proportion of dead cells. A western blot analysis showed that miR-483-5p increased the protein expression of PCG-1, NRF1, and TFAM and reduced the protein expression of Bax and cleaved caspase 3, inhibiting the release of cytochrome c from mitochondria and alleviating oxidative stress injury by inhibiting the production of ROS and reducing MDA activity. We confirmed that miR-483-5p targeted TNFSF8 to regulate the AMPK/JNK pathway, thereby playing a neuroprotective role after cardiopulmonary resuscitation. Hence, this study provides further insights into strategies for inhibiting neurological impairment after cardiopulmonary resuscitation and suggests a potential therapeutic target for PCABI.

The Mesoproterozoic Jixian System (1.6–1.4 Ga) in the Luonan area, southern margin of the North China Craton (NCC), is characterized by complete development, continuous sedimentation and a low degr...

AIM OF STUDY: To determine the association between bioimpedence-detected ventilation and out-of-hospital cardiac arrest (OHCA) outcomes. METHODS: This is a retrospective, observational study of 560 OHCA patients from the Dallas-Fort Worth site enrolled in the Resuscitation Outcomes Consortium Trial of Continuous or Interrupted Chest Compressions During CPR from 4/2012 to 7/2015. We measured bioimpedance ventilation (lung inflation) waveforms in the pause between chest compression segments (Physio-Control LIFEPAK 12 and 15, Redmond, WA) recorded through defibrillation pads. We included cases ≥18 years with presumed cardiac cause of arrest assigned to interrupted 30:2 chest compressions with bag-valve-mask ventilation and ≥2 minutes of recorded cardiopulmonary resuscitation. We compared outcomes in two a priori pre-specified groups: patients with ventilation waveforms in

Based on isotopic, lithologic and electrical data and logging cycle analysis technique, stratigraphic sequences in the Middle–Upper Cambrian Xixiangchi Group in the Sichuan Basin and its adjacent area are divided, and its sedimentary characteristics and evolution are analyzed. The Xixiangchi Group can be divided into 5 third-order sequences (Sq1–Sq5), of which sequences I to III (Sq1–Sq3) are relatively complete, sequences IV and V are denuded in the Late Cambrian because of the Dian-Chuan paleo-uplifts. Third-order sequences of the Xixiangchi Group in this area have the characteristics of thin in the west and thick in the east, showing that the Caledonian paleo-uplift is a synsedimentary paleo-uplift and the paleogeomorphology in the platform is a gentle slope. Sequence I develops high stand systems tract and transgressive systems tract. The other third-order sequences are dominated by highstand systems tracts, and the transgressive systems tracts last shortly in time and are limited in area. The basic features of evaporative–restricted platform of gentle slope type developed continuously in the sedimentary period of the Xixiangchi Group, its sedimentary environment of “high in west and low in east” and the change of micro paleogeomorphology in the platform control the continuous development of sedimentary facies. Open platform is developed only in sequence I and sequence II, and the inner beach of the platform and the edge beach of the platform are mostly developed in sequence II and sequence III. It indicates that there are two platform margin zones in the study area, a relatively stable, large-scale platform marginal zone in NE Guizhou–Western Hunan and Hubei, and a moving and small-scale platform marginal zone in North Chongqing–Western Hubei. Key Words: Sichuan Basin, Middle– Upper Cambrian, Xixiangchi Group, sequence stratigraphy, third-order sequence, carbon isotope composition, lithofacies paleogeography, sedimentary environment evolution

Normally, trees on the side directly exposed to sunlight will grow faster than the opposing side. This phenomenon is termed plant phototropism. Moreover, palaeomagnetists have revealed that the Junnar Block has never rotated since the Mesozoic. The petrified woods in the Jiangjunmiao area of Qitai County show the positive phototropism direction of SSW220. By compared with the modern normal growth stumps in plain area, which have positive phototropism direction of SSW 219 ± 5, this observation supports the conclusion of palaeomagnetic researchers: the Junggar basin has never rotated since the Late Jurassic.

Background Devices that measure ventilation in the pre-hospital setting are deficient especially during early cardiopulmonary resuscitation (CPR) before placement of an advanced airway. Consequently, evidence is limited regarding the role of ventilation during early CPR and its effect on outcomes. Objective To develop software that automatically identifies ventilation waveforms recorded by defibrillators based on changes in transthoracic impedance during standard CPR. Methods This was an observational, retrospective analysis of non-traumatic pre-hospital cardiac arrest patients who received 30:2 CPR by emergency medical service rescuers. Data was collected from 550 cases recorded by the bioimpedance channel of defibrillators. Two expert clinicians independently assessed all episodes from the time of initial CPR until placement of an advanced airway, defined acceptable ventilation waveforms, and annotated the pauses between compressions with ventilation waveforms. We then developed software that incorporated the expert criteria and automatically annotated pauses with acceptable ventilations. Results A total of 7396 pauses were analyzed, mean(SD) duration of 30:2 CPR was 13 (8) min, with 13 (10) pauses/patient, and mean pause duration of 6 (3) s. Reviewer 1 and reviewer 2 identified 2375 and 2249 pauses with any acceptable ventilation, respectively, with an inter-rater reliability of 0.94. The novel software program reproduced expert annotation with excellent agreement (>0.8) and high accuracy, both sensitivity and specificity above 90%, compared to two reviewers. The software presented a substantial agreement with the reviewers (κ > 0.73) for ventilation counts in the pauses. Conclusion We developed a novel and reliable strategy that enables investigation of ventilation quality during standard CPR using thoracic bioimpedance. This strategy would allow a timely and reliable automatic annotation of large scale resuscitation datasets.

The purpose of this cross-sectional survey study is to quantitatively examine the differences in patient trust towards physicians between four different clinical departments in a Chinese hospital. Using a validated modified Chinese version of the Wake Forest Physician Trust Scale, we measured patient trust in each department, and also collected data on patient demographics. A total of 436 patients or family members were surveyed in the departments of emergency medicine, pediatrics, cardiology, and orthopedic surgery. Significant differences were found between the departments, especially between pediatrics (trust score 43.23, range 11–50) and emergency medicine and cardiology (trust scores 45.29 and 45.79, respectively with range of 11–50). The average total score across all four departments was 44.72. There are indications that specifically comparing departments, such as patient demographics or department structure, could be helpful in tailoring patient care to improve physician-patient relationships.

With the development of Cardiopulmonary Resuscitation (CPR) technology and the popularity of public CPR...

An amended species, Nilssoniopteris neimenguensis ( Wang, 1984 ) Zhao et Deng, nom. nov., is described from the Lower Jurassic Hongqi Formation of the Xilinhot Basin, Inner Mongolia, northern China, based on leaf macromorphology and cuticular structures. Following a reexamination of the specimens published in the previous literature, a total of 86 species of Nilssoniopteris are recognized, and their stratigraphic and geographic distributions are analyzed. Nilssoniopteris first occurs in the Carnian of the Late Triassic of Central Europe and the southwest region of the United States. This genus spreads in the Euro-Sinian region in the Late Triassic and then gradually extends to the Siberian-Canadian region in the Early to Middle Jurassic, where it first experiences diversification and distribution expansion. After a decline in both diversity and geographic range in the Late Jurassic, Nilssoniopteris species flourish and almost completely migrate to the Siberian-Canadian region during the Early Cretaceous, and the genus finally dies out in the Cenomanian of the Late Cretaceous. The paleoclimatic conditions of Nilssoniopteris also experience a change from the subtropical-tropical zone to the warm temperate zone, indicating that the species may have grown in the warm humid temperate and subtropical-tropical zones with a general preference for warm, humid climates.

Rotor broken strip of asynchronous motor is not obvious and usually cannot be judged accurately because of on-site noise, equipment installation and other various interferences. In this paper, a simulation of rotor broken bar fault is conducted in SIMULINK environment, and the motor fault is simulated by changing the external resistance of the wound asynchronous motor. Through simulation and analysis of various combinations of several external resistors, the variation law of stator current frequency under varying fault degree is revealed. This model is feasible and can simulate different degrees of broken bar fault in order to approximate various working conditions. The simulation results show that the spectrum analysis method can be effectively applied to the diagnosis of motor rotor broken bar fault, and the correctness of the simulation model is verified.

The Yanchang Formation is extensively developed in the Ordos Basin and its surrounding regions. As one of the best terrestrial Triassic sequences in China and the major oil-gas bearing formations in the Ordos Basin, its age determination and stratigraphic assignment are important in geological survey and oil-gas exploration. It had been attributed to the Late Triassic and regarded as the typical representative of the Upper Triassic in northern China for a long time, although some scholars had already proposed that the lower part of this formation should be of the Middle Triassic age in the mid-late 20th century. In this paper, we suggest that the lower and middle parts of the Yanchang Formation should be of the Ladinian and the bottom possibly belongs to the late Anisian of the Middle Triassic, mainly based on new fossils found in it and high resolution radiometric dating results. The main source rocks, namely the oil shales and mudstones of the Chang-7, are of the Ladinian Age. The upper part of the Yanchang Formation, namely the Chang-6 and the above parts, belongs to the Late Triassic. The uppermost of the Triassic is missed in most parts of the Ordos Basin. The Middle-Upper Triassic Series boundary lies in the Yanchang Formation, equivalent to the boundary between Chang-7 and Chang-6. The Ladinian is an important palaeoenvironmental turning point in the Ordos Basin. Palaeoenvironmental changes in the basin are coincidence with that of the Sichuan Basin and the main tectonic movement of the Qinling Mountains. It indicates that tectonic activities of the Qinling Mountains are related to the big palaeoenvironmental changes in both the Ordos and Sichuan Basins, which are caused by the same structural dynamic system during the Ladinian.

The Middle–Upper Cambrian Xixiangchi Group in the Sichuan Basin is mainly a set of dolomites of platform facies. In the past, there was no effective way to determine the bottom boundary mark of the Upper Cambrian strata, so natural gas exploration of this horizon lagged behind. In this paper, it is revealed from the C and O isotopic profile of debris that in the middle of the Xixiangchi Group, there is a positive excursion event of carbon isotopes that can be correlated all over the world, so it can be used as an important mark to identify the Furongian Series (equivalent to the Upper Cambrian strata). Then, based on the characteristics of electric curves, the Furongian Series boundary mark was determined and its classification program was worked out preliminarily. It is shown that during the deposition of the Xixiangchi Group, it is a paleo-geomorphologically gentle-slope carbonate platform which is high in the east and low in the east, and a thin–moderate dolomite layer which is thin in the west and thick in the east is deposited. This layer is vertically divided into 4 intervals. Besides, the bottom boundary mark of the Furongian Series in the Sichuan Basin and its adjacent areas can be determined by combining the SPICE (Steptoean Positive Carbon Isotope Excursion) event of carbon isotopes with the characteristics of electric curves. Finally, the carbon isotope mark of the Furongian Series bottom boundary is the SPICE event corresponding to the positive excursion which is regionally correlated, the corresponding electrical mark is the GR small peak areas in the middle of the Xixiangchi group, and the corresponding lithologic symbol is the argillaceous dolomite. The research results are conducive to the further subdivision of the Xixiangchi Group in the Sichuan Basin and its adjacent areas and promoting the study on sedimentary evolution and reservoir distribution laws so that gas exploration in this series of strata can be speeded up. Keywords: Sichuan Basin, Late Cambrian, Xixiangchi Group, Furongian Series, Stratigraphic mark, Carbon isotope, Positive excursion, GR, Sedimentary environment

Two new species ofNilssoniopterisof the order Bennettitales,Nilssoniopteris hamiensisZhao and Deng, new species andNilssoniopteris crassiaxisZhao and Deng, new species, are established from the Xishanyao Formation (Middle Jurassic) of Sandaoling Coal Mine in Hami, Xinjiang, China, based on leaf macromorphology and cuticular features.Nilssoniopteris hamiensisn. sp. is characterized by its varied leaf shapes and trichome bases of 1–4 cells on the abaxial epidermis.Nilssoniopteris crassiaxisn. sp. is characterized by its broad midrib (especially near the leaf base) and trichome bases of 1–3 cells on the abaxial epidermis. Both species possess unique venation patterns that are not only simple and free, but also forked and merged to form closed loops. These anastomosing veins are even more complicated inN.crassiaxisn. sp. in that the veins can fork once, twice, or even three times, the forked veins can later merge with each other or with an adjacent vein to form a closed loop, which may later further disjoin. The generic diagnosis ofNilssoniopterisis thus accordingly emended, particularly in the venation pattern. In addition, the stratigraphic and geographical distributions of all 45 JurassicNilssoniopterisspecies worldwide have been summarized and analyzed to better understand their brief evolutionary history, indicating thatNilssoniopterismight be able to grow not only in subtropical regions as the living cycads are, but also in warm climatic regions.

Aim To evaluate the performance of a state-of-the-art cardiopulmonary resuscitation (CPR) artefact suppression method by assessing to what extent the filtered electrocardiogram (ECG) can be correctly diagnosed by emergency medicine doctors. Methods A total of 819 ECG segments were used. Each segment contained two consecutive 10 s intervals, an artefact free interval and an interval corrupted by CPR artefacts. Each ECG segment was digitally processed to remove CPR artefacts using an adaptive filter. Each ECG segment was split into artefact-free and filtered intervals, randomly reordered for dissociation, and independently offered to four reviewers for rhythm annotation. The rhythm annotations of the artefact-free intervals were considered as the gold standard against which the rhythm annotations of the filtered intervals were evaluated. For the filtered intervals, the rater agreement (κ, Kappa score) with the gold standard, the sensitivity and the specificity were computed individually for each reviewer, and jointly through the majority decision of the pool of reviewers (DPR). These results were also compared to those obtained using a commercial shock advisory algorithm (SAA). Results The agreement between each reviewer and the gold standard was moderate ranging between κ = 0.41–0.64. The sensitivities and specificities ranged between 64.3–95.0%, and 70.0–95.9%, respectively. The agreement for the DPR was substantial with κ = 0.64 (0.62–0.66), a sensitivity of 90.6%, and a specificity of 85.6%. For the SAA, the agreement was fair with κ = 0.33 (0.31–0.35), a sensitivity of 90.3%, and a specificity of 66.4%. Conclusion Clinicians outperformed the SAA, but specificities remained below the specifications recommended by the American Heart Association. Visual assessment of the filtered ECG by clinicians is not reliable enough, and varies greatly among clinicians. Results considerably improve by considering the consensus decision of a pool of clinicians.

Carbon isotope stratigraphic records across the Triassic-Jurassic (Tr-J) boundary show carbon isotope excursions in both marine and terrestrial sections, indicating frequent perturbations of the global carbon cycles, which are linked to the ~600 kyr pulsed emplacement of the Central Atlantic Magmatic Province (CAMP). However, few detailed carbon isotope stratigraphic reports from high-latitude terrestrial deposition have been documented in contrast to the contemporaneous low- to mid-latitude records. It hampers the understanding of the climatic response in the high-latitude terrestrial areas and the modeling global carbon cycles triggered by CAMP volcanisms. Here, we present high-resolution organic carbon isotope data primarily originated from C3 plants in the Haojiagou section in the paleo-high-latitude Junggar Basin, NW China. Combined with previously published biostratigraphic and geochemical results, carbon isotope stratigraphy with distinct “initial negative carbon isotope excursions” (I-CIE) and “main negative carbon isotope excursions” (M-CIE) is built in the Junggar Basin and allows a global stratigraphic correlation. The end-Triassic mass extinction (ETE) and the Tr-J boundary is then well identified. The excursion magnitude is similar to that in Greenland and Poland where the sections are also terrestrial. Climatic pattern recorded in the Junggar Basin rapidly changed across the Tr-J transition and coincides with a bloom of fern spores, increased wildfire activities, enhanced hydrological cycles and soil loss.

Fossil life in the Precambrian is commonly preserved as carbonaceous compressions, where Pre-Cryogenian carbonaceous compressions mainly occur in organic-poor rocks. Black-shale-preserved carbonaceous compressions have become more common since the Ediacaran Period. To explore the depositional context of carbonaceous compressions, micro X-ray fluorescence spectroscopy (μ-XRF) was used to image elemental distributions in carbonaceous compressions and surrounding rocks in Mesoproterozoic and Ediacaran-aged rocks. The carbonaceous compressions preserved in the Xiamaling green silty mudstones (1.40 Ga) and Lantian black shales (0.63 Ga) were selected and scanned, respectively. The behavior of redox-sensitive elements (Mo, U, V, Zn, Cu) in the Xiamaling and Lantian rocks and carbonaceous compressions suggest that the overlying water conditions during their sedimentation were not sulfidic. However, the co-enrichments of Fe and S in Xiamaling and Lantian carbonaceous compressions indicate pyrite permineralization. The Lantian carbonaceous compressions have a higher pyrite permineralization degree and a lower organism decomposition degree than those of the Xiamaling carbonaceous compressions. We speculate that these differences are related to a higher sulfate reduction rate and a lower dissimilatory iron reduction rate in the sediments hosting the Lantian carbonaceous compressions. Such conditions might be achieved through rapid burial and encircling by clay minerals. Overall, our results shed new light on understanding the preservation processes of the Precambrian life and the influence of environmental factors.

The plant macrofossils from the Lower Jurassic coal-bearing Hongqi Formation in the Xilinhot Basin, central Inner Mongolia of North China, are systematically documented for the first time. The flora contains 40 species of 21 genera, belonging to horsetails, ferns, Cycadopsida, Ginkgopsida, conifers, and isolated seeds of unknown affinity. The Filicopsida, predominant in the flora, are characterized by high species diversity of form genus Cladophlebis (with 12 species), abundant Hausmannia ( Protorhipis ) of the Dipteridaceae, and existence of Coniopteris and Eboracia of the Dicksoniaceae. Among the gymnosperm group, the Ginkgopsida rank the second of the flora, with nine species representing Ginkgoites , Sphenobaiera of ginkgoales and Phoenicopsis , Czekanowskia of czekanowskiales. The Cycadopsida consist of six species, four of which belong to genera Anomozamites , Pterophyllum , Nilssoniopteris , and Ptilophyllum of bennettitales and the other two to Nilssonia and Ctenis of cycadaleans. Conifers, with a relatively smaller number of species, are characterized by long and broad leaves, including genera Podozamites , Elatocladus , and Pityophyllum . Based on the stratigraphical ranges of the known species, the existence of Coniopteris and Eboracia , and the abundance of Hausmannia and Cladophlebis , the age of the studied flora can be determined as late Early Jurassic and possibly the Toarcian. The existence of climate sensitive elements, particularly the thermophilous plants such as the dipteridaceous fern Hausmannia , bennettitales Ptilophyllum , further demonstrates that the climate of Xilinhot area during the late Early Jurassic was warm and humid, but could be hot and even arid as in the subtropic zone at short intervals. It was warmer than during both the early Early Jurassic and early Middle Jurassic, indicating a temperature rising event occurred in the late Early Jurassic. Palaeobotanical and sedimentary data also support the conclusion that a warming and somewhat arid climatic event occurred in the terrestrial area of North China. This climate change event was coincided possibly with the Toarcian Oceanic Anoxic Event (T-OAE), and could be the response of the terrestrial ecological system to the great and rapid change of palaeoenvironment in the marine ecosystem.

Carbon and oxygen isotope analysis of Xixiangchi Group shows that the bottom boundary of the Upper Cambrian is defined for the first time. The Xixiangchi Group formed in a high salinity on shore marine sedimentary environment with a warm to dry climate and underwent a slow regression after a rapid transgression in the early and middle stages, In the late stage it entered a rapid regression after a slow transgression.

This study investigated the effects of hypothermia induced before cardiac arrest or after return of spontaneous circulation (ROSC) on cardiac function and myocardial mitochondrial injury after ROSC in a rat cardiac arrest model. Sixty healthy, male Wistar rats were randomly divided into the Normothermia group, pre-arrest hypothermia (Pre-HT) group, and post-resuscitation hypothermia (Post-HT) group. The rats underwent 8 min of untreated ventricular fibrillation followed by cardiopulmonary resuscitation. Twelve rats in each group were used to evaluate the left ventricular ejection fraction before ventricular fibrillation and 4 h after ROSC. Survival was determined at 24 h after ROSC. The remaining eight rats in each group were used to detect for heart malondialdehyde, reduced glutathione, adenosine triphosphate levels and mitochondrial histology. Oxygen consumption rate and mitochondrial membrane potential were evaluated 4 h after ROSC; 10 of 12 rats in Pre-HT group, 5 of 12 in Post-HT group, and 6 of 12 in normothermia group were successfully resuscitated. The survival rate of each group was 66.7%, 33.3%, and 25%, respectively. Rats in the Pre-HT group showed less alteration of the mitochondrial ultrastructure and oxidative stress injury, better maintenance of adenine nucleotides, and more preservation of the mitochondrial membrane potential and respiratory function when compared with rats in the Post-HT and normothermia groups. Transient hypothermia is an effective preconditioning stimulus to induce ischemic tolerance in a cardiac arrest model and worthy of further evaluation for potential clinical use. Impact statement In this paper, we investigated the effects of hypothermia induced before ischemia or after ROSC on cardiac function, oxidative stress damage, and myocardial mitochondrial ischemia–reperfusion injury after cardiac arrest in a rat model with VF. We demonstrated that pre-arrest hypothermia conferred greater cardio-protective benefits than delayed post-resuscitation hypothermia, reduced the number of defibrillations required and dosages of epinephrine during CPR, decreased oxidative stress, ameliorated mitochondrial dysfunction, and subsequently improved survival rate.

Mild hypothermia treatment (MHT) improves the neurological function of cardiac arrest (CA) patients, but the exact mechanisms of recovery remain unclear. Herein, we generated a CA and cardiopulmonary resuscitation (CPR) mouse model to elucidate such function. Naive mice were randomly divided into two groups, a normothemia (NT) group, in which animals had normal body temperature, and a MHT group, in which animals had a body temperate of 330C (range: 32-340C), after the return of spontaneous circulation (ROSC), followed by CA/CPR. MHT significantly improved the survival rate of CA/CPR mice compared with NT. Mechanistically, MHT increased the expression of Silent Information Regulator 1 (Sirt1) and decreased P53 phosphorylation (p-P53) in the cortex of CA/CPR mice, which coincided with the elevated autophagic flux. However, Sirt1 deletion compromised the neuroprotection offered by MHT, indicating that Sirt1 plays an important role. Consistent with the observations obtained from in vivo work, our in vitro study utilizing cultured neurons subjected to oxygen/glucose deprivation and reperfusion (OGD/R) also indicated that Sirt1 knockdown increased OGD/R-induced neuron necrosis and apoptosis, which was accompanied by decreased autophagic flux and increased p-P53. However，the depletion of P53 did not suppress neuron death, suggesting that P53 was not critically involved in MHT-induced neuroprotection. On the contrary, the application of autophagic inhibitor 3-methyladenine attenuated MHT-improved neuron survival after OGD/R, further demonstrating that increased autophagic flux significantly contributes to MHT-linked neuroprotection of CA/CRP mice. Our findings indicate that MHT improves neurological outcome of mice after CA/CPR through Sirt1-mediated activation of autophagic flux. Funding Statement: This study was supported by funding from the National Nature Science Foundation of China (81272021, 81571867), and the Fourth Batch of Youth Talent Project in the First Affiliated Hospital of Sun Yat-sen University (No.Y50152). Declaration of Interests: The authors declare that they have no conflict of interest. Ethics Approval Statement: This project was approved by the Animal Investigation Committee of Sun Yat-sen University and the animal protocol conformed with National Institutes of Health Guidelines for ethical animal research.

Trees grow towards the sunlight via a process of phototropism. The trunk phototropism processes are frequently observed in Northern Hemisphere from high latitude to at least the Tropic of Cancer region, and also occur in some in situ preserved vertical petrified woods in various geological ages. However, such evidence is still very limited and poorly known in fossil record; and the relationship between tree ring phototropism and rotation of tectonic blocks is unclear. Here we report the eccentricities of living and fossil trees as a proxy to determine geological block rotation at the same latitudes within the North China Block. The dominant eccentricity of living trees is southwest 219° ± 5°. By contrast, standing in situ fossil trunks in the Mid-Late Jurassic Tiaojishan Formation and the Late Jurassic Tuchengzi Formation had average eccentricities of 237° and 233.5°, respectively. These differences shed light on the palaeogeographical changes, indicating that the North China Block rotated clockwise from the Late Jurassic to the present day. This result is largely coincident with the palaeomagnetic results, indicating that the North China Block rotated clockwise by 26.5° ± 5.5° since the Middle to Late Jurassic transition.

Based on the global position system (GPS) radiosonde data near the sea surface, the surface duct characteristics over the South China Sea (SCS) were statistically analyzed. The annual surface duct occurrence over the SCS was about 64%. Of the observed surface ducts, duct heights mainly distributed between 18 and 42 m, with M slopes in the range of–0.3 to–0.2 M units/m. Those ducts accounted for about 80% of the ducting cases. For the total profiles, the duct occurrences in a day changed slowly and were more than 60% in all times. The surface ducts formed more easily in the daytime than in the nighttime and most of the duct height were at bellow about 32 m. Additionally, The seasonal variation of the SCS ducts appeared to be evident, except that the mean duct thickness was almost constant, about 33 m for all seasons. The highest occurrence was about 71% in the autumn, followed by in the summer, spring and winter. In spring, their top-height existed more often at a height of more than 48 m. Their mean duct strength became stronger trend from spring to winter, with the M-slope in the range between–0.26 and–0.18 M units/m. Those results agreed well with other studies, provided considering the data resolution. The statistical analysis was reliable and gave the duct estimation for the SCS. Such duct climatology not only has important implications for communication systems and the reliability of the radar observation, but also can provide useful information to improve the accuracy of the meteorological radar measurements.

The observed characteristics of lower atmospheric ducts over the South China Sea (SCS) were analyzed based on Global Position Systerm (GPS) radiosonde data collected four times daily during autumn open cruises from 2006 to 2012. Duct occurrence, thickness, and strength over the SCS were about 40%, 150-m thick, and 8 M units, respectively, which were larger than during the summer monsoon period. Most ducts occurred at heights

Samples of Upper Ordovician marine carbonates from four sections on the Yangtze Platform (1, the Liangcun section northeast of Xishui County Town, Guizhou Province; 2, the Zhuazhuayan section southwest of Leibo County Town, Sichuan Province; 3, the Xiaogangwan section east of Wulong County Town, Chongqing Municipality; 4, the Shatan section north of Nanjiang County Town, Sichuan Province) have been analyzed for carbon isotope (δ 13 C) chemostratigraphy. A distinct positive δ 13 C excursion (δ 13 C max > 2) is observed in all sections, which ranges through the Hamarodus brevirameus conodont zone, and locally into slightly younger strata. The base of this zone is the First Appearance Datum (FAD) of H. brevirameus and its top coincides with the FAD of the conodont Protopanderodus insculptus . Based on its position in the H. brevirameus zone, this excursion is identified as the well-known Guttenberg Excursion (GICE) confirming the global significance of this paleoceanographic event. The fact that in the Black Knob Ridge section in the USA, the GSSP of the base of the global Katian Stage, the beginning of the GICE is just below the base of the Katian makes it possible to locate this key level in our study sections even in the absence of the diagnostic graptolite Diplacanthograptus caudatus . Our carbon curves through the GICE interval show three minor secondary peaks reflecting paleoceanographic changes or selective preservation of the isotope signal. However, because a global review of the GICE shows that such minor peaks, which are often based on a single elevated δ 13 C value, are of irregular occurrence, they are interpreted as local, rather than global, phenomena. The suggested global cooling in the early Katian might have favored the generation of methane hydrates and hence the reduction of the amount of 12 C in the marine carbonates.

Trees on the side directly exposed to sunlight generally grow faster than on the opposite side, a phenomenon termed plant phototropism. There are in situ vertical trunks of silicified wood in the Xiadelongwan area of Yanqing County, north Beijing, where the first National Geologic Park of Petrified Wood of China has been built since 2002. A few trunks have well-preserved growth rings. One petrified stump from the formation shows a positive phototropism direction of SW230°. As compared with the modern normal growth stumps in Beijing plain area, which have a positive phototropism direction of SW210 ° ± 5°, the evidence of wood phototropism supports the conclusion of previous palaeomagnetic studies that the North China Plate has rotated clockwise since the Late Jurassic. The known petrified wood stumps in the Yanshan-Liaoning area are mainly found from the strata of 165–136 Ma, which corresponds to the main stage of the Yanshanian Movement.

Conodonts from the Cambrian–Ordovician transition at the Liangcun section in Xishui County, Guizhou and at the Huangcao section in Wulong County, Chongqing are examined for the first time. Both sections are located at the southeast margin of the Sichuan Basin. A total of 1367 specimens were recovered, representing 30 species and 15 genera. Based on the ranges of conodonts generalized from these two sections and another six sections previously studied in the same region, three conodont zones, Cordylodus proavus, Monocostodus sevierensis and Cordylodus angulatus zones are recognized. The index species of the Cambrian–Ordovician boundary at the global stratotype section and point (GSSP), Iapetognathus fluctivagus and its substitute in China Iapetognathus jilinensis are not observed in the study sections, therefore it is impossible to determine the Cambrian–Ordovician boundary exactly. However, it probably lies within the lower part of M. sevierensis zone (the upper part of the Loushanguan Group), correlating with the GSSP in Canada and the Dayangcha section in China. Chronological sequences of the FAD (First Appearance Datum) of C. angulatus , Chosonodina herfurthi and Rossodus manitouensis are not obvious in the study, so the C. angulatus zone here is correlated with zones defined by C. angulatus , Ch. herfurthi and R. manitouensis in the lower Yangtze Platform.

Background Return of spontaneous circulation (ROSC) in the field is a vital determinant contributing to survival from out-of-hospital cardiac arrest (OHCA). However, nearly one third of survivors at the Dallas-Fort Worth (DFW) Resuscitation Outcomes Consortium (ROC) site did not obtain ROSC in the field. Methods A retrospective, observational analysis was performed on all adult patients with non-traumatic OHCA treated on scene and transported to hospital, who did not gain ROSC in the field at DFW ROC site between 2006 through 2011.We described the demographics, pre-hospital characteristics and outcomes of all enrolled cases. Those patients without ROSC in the field, who did and did not meet Termination of Resuscitation (TOR) criteria in the field, were also compared. Results Among a total of 5099 treated and transported non-traumatic OHCA cases, 83.2% (4243) were included in this study as patients without ROSC gained in the field, of which 66.6% (2827) met TOR criteria but still were treated and transported; 1.9% (79) survived to hospital discharge. Further analysis showed that 39.2% (31) of survivors met TOR rule, accounting for 1.1% of those patients who should have been declared dead in the field. Shockable initial rhythms, EMS-witnessed arrest, bystander CPR and age were factors significant to predict survival from OHCA without ROSC in the field. Of concern, 1.7% (47) of patients who met TOR presented initially shockable rhythms but no shocks were delivered in the field. Conclusions We suggest that all treated non-traumatic OHCA patients should be transported to hospital.