Effect of Arbuscular Mycorrhizal Fungi (AMF) on photosynthetic characteristics of cotton seedlings under saline-alkali stress.

The study aimed to find the best Arbuscular Mycorrhizal Fungi (AMF) strain for cotton growth in Xinjiang's salinity and alkali conditions. Cotton (Xinluzao 45) was treated with Funneliformis mosseae (GM), Rhizophagus irregularis (GI), and Claroideoglomus etunicatum (GE) as treatments, while untreated cotton served as the control (CK). Salinity stress was applied post-3-leaf stage in cotton. The study analyzed cotton's reactions to diverse saline-alkali stresses, focusing on nutrient processes and metabolism. By analyzing the growth and photosynthetic characteristics of plants inoculated with Funneliformis mosseae to evaluate its salt tolerance. Saline-alkali stress reduced chlorophyll and hindered photosynthesis, hampering cotton growth. However, AMF inoculation mitigated these effects, enhancing photosynthetic rates, CO2 concentration, transpiration, energy use efficiency, and overall cotton growth under similar stress levels. GM and GE treatments yielded similar positive effects. AMF inoculation enhanced cotton plant height and biomass. In GM treatment, cotton exhibited notably higher root length than other treatments, showing superior growth under various conditions. In summary, GM-treated cotton had the highest infection rate, followed by GE-treated cotton, with GI-treated cotton having the lowest rate (GM averaging 0.95). Cotton inoculated with Funneliformis mosseae, Rhizophagus irregularis, and Claroideoglomus etunicatum juvenile showed enhanced chlorophyll and photosynthetic levels, reducing salinity effects. Funneliformis mosseae had the most significant positive impact.

Comparative life cycle assessment of cement, sintered bricks and non-sintered bricks manufacturing using water-based drilling cuttings from shale gas production in the Sichuan Basin, China.

This study determined the environmental impacts of three recycling pathways for water-based drilling cuttings (WDC), namely cement, sintered bricks, and non-sintered bricks, based on the life cycle assessment (LCA) method. A life cycle inventory was developed with based on the resource utilization of 1t drilling cuttings as the functional unit, and a sensitivity analysis was conducted to identify the essential materials and energy consumption. The results showed that the sequence of the environmental impact index for the three recycling pathways was cement, non-sintered brick and sintered brick. Primary energy demand and direct emissions were the main reasons for this difference. Direct emissions, electricity, and binder were the largest contributors to the inventory of cement, sintered bricks, and non-sintered bricks, accounting for 54%, 33.4%, and 62.1% of the environmental impact burden, respectively. Furthermore, a 5% reduction in direct emissions, electricity, and binder decreased the integrated impact index by approximately 2.67%, 3.04%, and 3.38% for cement, sintered bricks, and non-sintered bricks, respectively. Based on the LCA results, strategies for reducing emissions and conserving energy were proposed. These results provide a useful reference for creating a sustainable system for recycling water-based drilling cuttings.

Obliquity pacing of the western Pacific Intertropical Convergence Zone over the past 282,000 years.

The Intertropical Convergence Zone (ITCZ) encompasses the heaviest rain belt on the Earth. Few direct long-term records, especially in the Pacific, limit our understanding of long-term natural variability for predicting future ITCZ migration. Here we present a tropical precipitation record from the Southern Hemisphere covering the past 282,000 years, inferred from a marine sedimentary sequence collected off the eastern coast of Papua New Guinea. Unlike the precession paradigm expressed in its East Asian counterpart, our record shows that the western Pacific ITCZ migration was influenced by combined precession and obliquity changes. The obliquity forcing could be primarily delivered by a cross-hemispherical thermal/pressure contrast, resulting from the asymmetric continental configuration between Asia and Australia in a coupled East Asian-Australian circulation system. Our finding suggests that the obliquity forcing may play a more important role in global hydroclimate cycles than previously thought.

Acceleration of modern acidification in the South China Sea driven by anthropogenic CO2.

Modern acidification by the uptake of anthropogenic CO2 can profoundly affect the physiology of marine organisms and the structure of ocean ecosystems. Centennial-scale global and regional influences of anthropogenic CO2 remain largely unknown due to limited instrumental pH records. Here we present coral boron isotope-inferred pH records for two periods from the South China Sea: AD 1048-1079 and AD 1838-2001. There are no significant pH differences between the first period at the Medieval Warm Period and AD 1830-1870. However, we find anomalous and unprecedented acidification during the 20th century, pacing the observed increase in atmospheric CO2. Moreover, pH value also varies in phase with inter-decadal changes in Asian Winter Monsoon intensity. As the level of atmospheric CO2 keeps rising, the coupling global warming via weakening the winter monsoon intensity could exacerbate acidification of the South China Sea and threaten this expansive shallow water marine ecosystem.

Mysterious abrupt carbon-14 increase in coral contributed by a comet.

A large and sudden increase in radiocarbon ((14)C) around AD 773 are documented in coral skeletons from the South China Sea. The (14)C increased by ~ 15‰ during winter, and remain elevated for more than 4 months, then increased and dropped down within two months, forming a spike of 45‰ high in late spring, followed by two smaller spikes. The (14)C anomalies coincide with an historic comet collision with the Earth's atmosphere on 17 January AD 773. Comas are known to have percent-levels of nitrogen by weight, and are exposed to cosmic radiation in space. Hence they may be expected to contain highly elevated (14)C/(12)C ratios, as compared to the Earth's atmosphere. The significant input of (14)C by comets may have contributed to the fluctuation of (14)C in the atmosphere throughout the Earth's history, which should be considered carefully to better constrain the cosmic ray fluctuation.

Interannual variation of rare earth element abundances in corals from northern coast of the South China Sea and its relation with sea-level change and human activities.

Here we present interannual rare earth element (REE) records spanning the last two decades of the 20th century in two living Porites corals, collected from Longwan Bay, close to the estuarine zones off Wanquan River of Hainan Island and Hong Kong off the Pearl River Delta of Guangdong Province in the northern South China Sea. The results show that both coral REE contents (0.5-40 ng g⁻¹ in Longwan Bay and 2-250 ng g⁻¹ in Hong Kong for La-Lu) are characterized with a declining trend, which are significantly negative correlated with regional sea-level rise (9.4 mm a⁻¹) from 1981 to 1996 in Longwan Bay, 13.7 mm a⁻¹ from 1991 to 2001 in Hong Kong). The REE features are proposed to be resulted from seawater intrusion into the estuaries in response to contemporary sea-level rise. However, the tendency for the coral Er/Nd time series at Hong Kong site is absent and there is no significant relation between Er/Nd and total REEs as found for the coral at Longwan Bay site. The observations are likely attributed to changes of the water discharge and sediment load of Pearl River, which have been significantly affected by intense human activities, such as the construction of dams/reservoirs and riverbed sediment mining, in past decades. The riverine sediment load/discharge ratio of the Pearl River decreased sharply with a rate of 0.02 kg m⁻³ a⁻¹, which could make significant contribution to the declining trend of coral REE. We propose that coastal corals in Longwan Bay and similar unexplored sites with little influences of river discharge and anthropogenic disruption are ideal candidates to investigate the influence of sea-level change on seawater/coral REE.

[Multi-modalities for reconstruction of circumferential defects in the pharyngoesophageal region].

OBJECTIVE: To investigate the feasibility of multi-modalities in the reconstruction of circumferential defects after resection of cancers in pharyngoesophageal regions, and to compare the pros and cons between different surgical procedures. METHODS: According to the nature and extend of defects, five different methods including pectoralis major myocutaneous flap, laryngeal tube replacement, free jejunum, free forearm flap and gastric pull-up were used to reconstruct the circumferential pharyngoesophageal defects in 72 patients. Function of deglutition and restoration of swallowing was regularly followed up and objectively evaluated. RESULTS: A total of 35 cases of pectoralis major myocutaneous (PM) flaps, 8 cases of laryngeal tube replacement, 12 cases of free jejunum, 12 cases of free forearm flaps and 16 cases of gastric pull-up were performed. Different complications including wound infection, pharyngeal fistula, partial necrosis of PM flap, partial necrosis of gastric wall, stricture of anastomotic site were encountered in 15 cases. All patients survived the operation except one due to partial necrosis of the gastric wall. Two of 4 patients who developed anastomotic stricture can ingest half-liquid food, the remaining cases regained normal deglutition function. The mean postoperative follow-up time was 1. 6 years with 2-year survival rate of 45.3%. CONCLUSIONS: Circumferential defects resulting from resection of carcinomas in pharyngoesophageal region can be reconstructed with different operative techniques depending on the nature and extend of the defects. Once the operative indications are properly selected, the good reconstructive results are to be achieved.

Comparative on causes and accumulation of selenium in the tree-rings ambient high-selenium coal combustion area from Yutangba, Hubei, China.

Toxic trace elements emitted during coal combustion are the main sources of air pollution. They are released into the atmosphere mainly in the forms of fine ash, smoke and flue, and thus adversely affect plant, animal and human health. Selenium is one of toxic and the most volatile in coal. Large amount of atmospheric emission of selenium, as well as selenium present and scrubber stockpiles in ash may create serious environmental problems. In the paper, on the basis of investigating the abundance and distribution of selenium in plant-rings during recent 20 years, the bioaccumulation of selenium is explained that selenium in plant, which were collected from the village of selenium-rich coal combustion, is much higher than that in plants collected away from the village of selenium-rich coal combustion. The main origins of selenium are selenium-rich coal combustion and high-selenium rock weathered. The selenium recycle by food chain and selenium will accumulate and redistribute in environments.

Metal exposure and Alzheimer's pathogenesis.

With the growing aging population in Western countries, Alzheimer's disease (AD) has become a major public health concern. No preventive measure and effective treatment for this burdensome disease is currently available. Genetic, biochemical, and neuropathological data strongly suggest that Abeta amyloidosis, which originates from the amyloidogenic processing of a metalloprotein-amyloid precursor protein (APP), is the key event in AD pathology. However, neurochemical factors that impact upon the age-dependent cerebral Abeta amyloidogenesis are not well recognized. Growing data indicate that cerebral dysregulation of biometals, environmental metal exposure, and oxidative stress contribute to AD pathology. Herein we provided further evidence that both metals (such as Cu) and H(2)O(2) promote formation of neurotoxic Abeta oligomers. Moreover, we first demonstrated that laser capture microdissection coupled with X-ray fluorescence microscopy can be applied to determine elemental profiles (S, Fe, Cu, and Zn) in Abeta amyloid plaques. Clearly the fundamental biochemical mechanisms linking brain biometal metabolism, environmental metal exposure, and AD pathophysiology warrant further investigation. Nevertheless, the study of APP and Abeta metallobiology may identify potential targets for therapeutic intervention and/or provide diagnostic methods for AD.