The shallow shelf deltalstrand arenaceous-pelitic deposit region in the north of the Pearl River mouth basin, sitting on the northern continental shelf of the South China Sea, has already become an important oil production base in China. Recent researched has revealed that a great deal of deepwater fans of great petroleum potentiality exist on the Baiyun deep-water slope below the big paleo Pearl River and its large delta. Based on a mass of exploration wells and 2-D seismic data of the shallow shelf region, a interpretation of sequence stratigraphy confiied the existence of deep-water fans. The cyclic falling of sea level, abundant detrital matter from the paleo Pearl River and the persistent geothermal subsidence in the Baiyun sag are the three prerequisites for the formation and development of deepwater fans. There are many in common between the deepwater shelf depositional system of the northern South China Sea and the exploration hotspots region on the two banks of the Atlantic. For example, both arc located on passive continent margins, and persistent secular thermal subsidence and large paleo rivers have supplied abundant material sources and organic matter. More recently, the discovery of the big gas pool on the northern slope of the Baiyun sag confirms that the Lower Tertiary lacustrine facies in the Baiyun sag has a great potentiality of source rocks. The fans overlying the Lower Tertiary source rocks should become the main exploration areas for oil and gas resources.
A self-developed curing agent is used to solidify the municipal sludge taken from Tianjin. Then, the long-term deformation characteristics of the sludge solidified soil are investigated by means of unconsolidated undrained creep tests with different dry-wet cycles for considering the influence of climate. The experimental results show that the attenuation rate of the shear peak strength of municipal sludge solidified soil decreases gradually with the increase of the number of dry-wet cycles, and the strength remains unchanged when the number of dry-wet cycles is greater than 10. The variation laws under different initial static deviatoric stresses are basically identical. When the applied stress is less than the yield stress of the sludge solidified soil, the duration curves of creep show only attenuated stage, i.e., with very small deformation, and the deformation reaches a constant in a short period of time. When the deviatoric stress reaches the long-term strength of the soil, the instantaneous deformation of the sludge solidified soil becomes large and damage occurs quickly. Under the same deviatoric stress, the creep deformation increases with the increase of the number of dry-wet cycles. When the load applied in each step is of the same magnitude, the higher the initial static deviatoric stress is, the larger the deformation of sludge solidified soil will be. It is found that the stress-strain relationship and the relationship between creep strain and time can be well described by an exponential function and a hyperbolic function, respectively. On this basis, a creep model is proposed for the long-term deformation considering the effect of dry-wet cycle times and initial static deviatoric stress. The model is further validated by comparing the predictions with the test results under different deviatoric stresses; the good agreement between which shows the potential application of the model to relevant practical engineering.
Purpose: To investigate the clinical efficacy of zoledronic acid plus percutaneous vertebroplasty in spinal metastasis, and its effect on serum levels of bone loss markers.
Methods: Sixty-two patients with spinal metastases were randomly divided into study group (n = 31) and control group (n = 31). The control group underwent percutaneous vertebroplasty, while study group received zoledronic acid plus. Analgesic effect, Japanese Orthopedic Association (JOA) score, improvement in movement ability, quality of life, carboxy-terminal cross-linked peptide of type I collagen (ICTP), procollagen type I N-terminal amino peptide (PINP), and bone-specific alkaline phosphatase (BALP) levels were compared between the two groups.
Results: The study group presented a higher degree of analgesic effectiveness and better performance than the control group (p < 0.05). After treatment, the Kamofsky function scores were increased in both groups, but it was higher in the study group (p < 0.05). After treatment, the JOA score of the study group was higher than the control group (p < 0.05). The post-treatment levels of ICTP, PINP and BALP decreased in both groups, but was markedly lower in the study group (p < 0.05).
Conclusion: A combination of percutaneous vertebroplasty and zoledronic acid is effective for the treatment of spinal metastasis. It enhances mobility, improves quality of life, reduces serum levels of bone loss markers, and produces good analgesic effect.
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