In this paper, the influence of soil liquefaction on the vertical pressure of submarine pipeline was investigated under the wave loading through the wave flume test. The experiment was set with the same waves on the l...In this paper, the influence of soil liquefaction on the vertical pressure of submarine pipeline was investigated under the wave loading through the wave flume test. The experiment was set with the same waves on the liquefied seabed and unliquefled seabed respectively, and the current pipeline vertical pressure was measured with the pressure transducers installed on the two opposite directions （i.e., straight up and straight down） at the same cross-section of the pipeline. The results showed that when the seabed was unliquefied, the two pressure curves varied periodically and overlapped completely, reaching the maximum and minimum at the same time respectively, and the resultant pressure fluctuated within a limited range. However, when the seabed was liquefied, the two pressure curves varied periodically, but they did not overlap completely. They did not reach the maximum （minimum） value at the same time either, and the resultant pressure fluctuated within a wider range. The experiment showed that the submarine stood higher resultant pressure in the vertical direction when the seabed was liquefied, which may cause the frequent sinking and fioatation of the pipeline, leading to its fatigue damage.展开更多
The human intestinal tract is home to an enormous bacterial flora. The host defense against microorganisms can be divided into innate and adaptive immunity. The former is the most immediate line of response to immunol...The human intestinal tract is home to an enormous bacterial flora. The host defense against microorganisms can be divided into innate and adaptive immunity. The former is the most immediate line of response to immunologic challenges presented by bacteria, viruses, and fungi. The mucosal immune system has evolved to balance the need to respond to pathogens while co-existing with commensal bacteria and food antigens. In inflammatory bowel disease （IBD）, this hyporesponsiveness or tolerance breaks down and inflammation supervenes driven by the intestinal microbial flora. Bacteria contain compounds and are recognized by a variety of receptors, including Toll-like receptors （TLRs） and NODs （a family of intracellular bacterial sensors） and are potent stimuli of innate immune responses. Several mutations in these receptors have been associated with development of IBD.展开更多
Suppression of Tumorigenicity 2 （ST2） is a member of the interleukin （IL）-1 receptor family The ST2 receptor exists in two isoforms - ST2 ligand （ST2L） and soluble ST2 （sST2）.ST2L is a membrane receptor and sS...Suppression of Tumorigenicity 2 （ST2） is a member of the interleukin （IL）-1 receptor family The ST2 receptor exists in two isoforms - ST2 ligand （ST2L） and soluble ST2 （sST2）.ST2L is a membrane receptor and sST2 is a trun- cated receptor which is soluble in the blood, allowing it to be detected in serum. IL-33 is a member of the IL-1 family of ligand and is the fimctional ligand of ST2L receptor. It binds to the ST2L, thereby mediating its immune function.展开更多
Celiac disease has been associated with some autoimmune disorders. A 40-year-old competitive strongman with celiac disease responded to a gluten-free diet, but developed profound and generalized motor weakness with ac...Celiac disease has been associated with some autoimmune disorders. A 40-year-old competitive strongman with celiac disease responded to a gluten-free diet, but developed profound and generalized motor weakness with acetylcholine receptor antibody positive myasthenia gravis, a disorder reported to occur in about 1 in 5000. This possible relationship between myasthenia gravis and celiac disease was further explored in serological studies. Frozen stored serum samples from 23 acetylcholine receptor antibody positive myasthenia gravis patients with no intestinal symptoms were used to screen for celiac disease. Both endomysial and tissue transglutaminase antibodies were examined. One of 23 (or, about 4.3%) was positive for both IgA-endomysial and IgA tissue transglutaminase antibodies. Endoscopic studies subsequently showed duodenal mucosal scalloping and biopsies confirmed the histopathological changes of celiac disease. Celiac disease and myasthenia gravis may occur together more often than is currently appreciated. The presence of motor weakness in celiac disease may be a clue to occult myasthenia gravis, even in the absence of intestinal symptoms.展开更多
It is believed that human ancestors evolved the ability to run bipedally approximately 2 million years ago. This form of locomotion may have been important to our survival and likely has influenced the evolution of ou...It is believed that human ancestors evolved the ability to run bipedally approximately 2 million years ago. This form of locomotion may have been important to our survival and likely has influenced the evolution of our body form. As our bodies have adapted to run, it seems unusual that up to 79% of modern day runners are injured annually. The etiology of these injuries is clearly multifactorial. However, 1 aspect of running that has significantly changed over the past 50 years is the footwear we use. Modern running shoes have become increasingly cushioned and supportive, and have changed the way we run. In particular, they have altered our footstrike pattern from a predominantly forefoot strike(FFS) landing to a predominantly rearfoot strike(RFS) landing. This change alters the way in which the body is loaded and may be contributing to the high rate of injuries runners experience while engaged in an activity for which they were adapted. In this paper, we will examine the benefits of barefoot running(typically an FFS pattern),and compare the lower extremity mechanics between FFS and RFS. The implications of these mechanical differences, in terms of injury, will be discussed. We will then provide evidence to support our contention that FFS provides an optimal mechanical environment for specific foot and ankle structures, such as the heel pad, the plantar fascia, and the Achilles tendon. The importance of footwear will then be addressed, highlighting its interaction with strike pattern on mechanics. This analysis will underscore why footwear matters when assessing mechanics. Finally, proper preparation and safe transition to an FFS pattern in minimal shoes will be emphasized. Through the discussion of the current literature, we will develop a justification for returning to running in the way for which we were adapted to reduce running-related injuries.展开更多
Agonist binding of A2A adenosine receptor （A2AAR） shows protective effects against inflammatory and immune. Efforts are exerted in understanding the general mechanism and developing A2AAR selectively binding agonist...Agonist binding of A2A adenosine receptor （A2AAR） shows protective effects against inflammatory and immune. Efforts are exerted in understanding the general mechanism and developing A2AAR selectively binding agonists. Using molecular dynamics （MD） simula- tions, we have studied the interactions between A2AAR and its agonist （adenosine）, and analyzed the induced dynamic behaviors of the receptor. Key residues interacting with adenosine are identified： A63^2.61,I66^2.64,V84^3.32,L85^3.33,T88^3.36,F168^5.29,M177^5.38,L249^6.51,H250^6.52 and N253^6.55 interacting with adenosine with affinities larger than 0.5 kcal/mol. Moreover, no interaction between adenosine and L167^5.28 is observed, which supports our previous findings that L1675^5.28 is an antagonist specific binding reside. The dynamic be- haviors of agonist bound A2AAR are found to be different from apo-A2AAR in three typical functional switches： （i） tight ＂ionic lock＂ forms in adenosine-A2AAR, but it is in equilibrium between formation and breakage in apo-A2AAR; （ii） the ＂rotamer toggle switch＂, T88^3.36/F242^6.44/W246^6.48, adopted different rotameric conformations in adenosin-A2AAR and apo-A2AAR; （iii） adenosine-A2AAR has a flexible intracellular loop 2 （IC2） and s-helical IC3, while apo-A2AAR preferred s-helical IC2 and flexible IC3. Our results indicate that agonist binding induced different conformational rearrangements of these characteristic functional switches in adenosine-A2AAR and apo-A2AAR.展开更多
基金supported by the grant from the National Natural Science Foundation of China (No. 41076021)
文摘In this paper, the influence of soil liquefaction on the vertical pressure of submarine pipeline was investigated under the wave loading through the wave flume test. The experiment was set with the same waves on the liquefied seabed and unliquefled seabed respectively, and the current pipeline vertical pressure was measured with the pressure transducers installed on the two opposite directions （i.e., straight up and straight down） at the same cross-section of the pipeline. The results showed that when the seabed was unliquefied, the two pressure curves varied periodically and overlapped completely, reaching the maximum and minimum at the same time respectively, and the resultant pressure fluctuated within a limited range. However, when the seabed was liquefied, the two pressure curves varied periodically, but they did not overlap completely. They did not reach the maximum （minimum） value at the same time either, and the resultant pressure fluctuated within a wider range. The experiment showed that the submarine stood higher resultant pressure in the vertical direction when the seabed was liquefied, which may cause the frequent sinking and fioatation of the pipeline, leading to its fatigue damage.
文摘The human intestinal tract is home to an enormous bacterial flora. The host defense against microorganisms can be divided into innate and adaptive immunity. The former is the most immediate line of response to immunologic challenges presented by bacteria, viruses, and fungi. The mucosal immune system has evolved to balance the need to respond to pathogens while co-existing with commensal bacteria and food antigens. In inflammatory bowel disease （IBD）, this hyporesponsiveness or tolerance breaks down and inflammation supervenes driven by the intestinal microbial flora. Bacteria contain compounds and are recognized by a variety of receptors, including Toll-like receptors （TLRs） and NODs （a family of intracellular bacterial sensors） and are potent stimuli of innate immune responses. Several mutations in these receptors have been associated with development of IBD.
文摘Suppression of Tumorigenicity 2 （ST2） is a member of the interleukin （IL）-1 receptor family The ST2 receptor exists in two isoforms - ST2 ligand （ST2L） and soluble ST2 （sST2）.ST2L is a membrane receptor and sST2 is a trun- cated receptor which is soluble in the blood, allowing it to be detected in serum. IL-33 is a member of the IL-1 family of ligand and is the fimctional ligand of ST2L receptor. It binds to the ST2L, thereby mediating its immune function.
文摘Celiac disease has been associated with some autoimmune disorders. A 40-year-old competitive strongman with celiac disease responded to a gluten-free diet, but developed profound and generalized motor weakness with acetylcholine receptor antibody positive myasthenia gravis, a disorder reported to occur in about 1 in 5000. This possible relationship between myasthenia gravis and celiac disease was further explored in serological studies. Frozen stored serum samples from 23 acetylcholine receptor antibody positive myasthenia gravis patients with no intestinal symptoms were used to screen for celiac disease. Both endomysial and tissue transglutaminase antibodies were examined. One of 23 (or, about 4.3%) was positive for both IgA-endomysial and IgA tissue transglutaminase antibodies. Endoscopic studies subsequently showed duodenal mucosal scalloping and biopsies confirmed the histopathological changes of celiac disease. Celiac disease and myasthenia gravis may occur together more often than is currently appreciated. The presence of motor weakness in celiac disease may be a clue to occult myasthenia gravis, even in the absence of intestinal symptoms.
文摘It is believed that human ancestors evolved the ability to run bipedally approximately 2 million years ago. This form of locomotion may have been important to our survival and likely has influenced the evolution of our body form. As our bodies have adapted to run, it seems unusual that up to 79% of modern day runners are injured annually. The etiology of these injuries is clearly multifactorial. However, 1 aspect of running that has significantly changed over the past 50 years is the footwear we use. Modern running shoes have become increasingly cushioned and supportive, and have changed the way we run. In particular, they have altered our footstrike pattern from a predominantly forefoot strike(FFS) landing to a predominantly rearfoot strike(RFS) landing. This change alters the way in which the body is loaded and may be contributing to the high rate of injuries runners experience while engaged in an activity for which they were adapted. In this paper, we will examine the benefits of barefoot running(typically an FFS pattern),and compare the lower extremity mechanics between FFS and RFS. The implications of these mechanical differences, in terms of injury, will be discussed. We will then provide evidence to support our contention that FFS provides an optimal mechanical environment for specific foot and ankle structures, such as the heel pad, the plantar fascia, and the Achilles tendon. The importance of footwear will then be addressed, highlighting its interaction with strike pattern on mechanics. This analysis will underscore why footwear matters when assessing mechanics. Finally, proper preparation and safe transition to an FFS pattern in minimal shoes will be emphasized. Through the discussion of the current literature, we will develop a justification for returning to running in the way for which we were adapted to reduce running-related injuries.
文摘Agonist binding of A2A adenosine receptor （A2AAR） shows protective effects against inflammatory and immune. Efforts are exerted in understanding the general mechanism and developing A2AAR selectively binding agonists. Using molecular dynamics （MD） simula- tions, we have studied the interactions between A2AAR and its agonist （adenosine）, and analyzed the induced dynamic behaviors of the receptor. Key residues interacting with adenosine are identified： A63^2.61,I66^2.64,V84^3.32,L85^3.33,T88^3.36,F168^5.29,M177^5.38,L249^6.51,H250^6.52 and N253^6.55 interacting with adenosine with affinities larger than 0.5 kcal/mol. Moreover, no interaction between adenosine and L167^5.28 is observed, which supports our previous findings that L1675^5.28 is an antagonist specific binding reside. The dynamic be- haviors of agonist bound A2AAR are found to be different from apo-A2AAR in three typical functional switches： （i） tight ＂ionic lock＂ forms in adenosine-A2AAR, but it is in equilibrium between formation and breakage in apo-A2AAR; （ii） the ＂rotamer toggle switch＂, T88^3.36/F242^6.44/W246^6.48, adopted different rotameric conformations in adenosin-A2AAR and apo-A2AAR; （iii） adenosine-A2AAR has a flexible intracellular loop 2 （IC2） and s-helical IC3, while apo-A2AAR preferred s-helical IC2 and flexible IC3. Our results indicate that agonist binding induced different conformational rearrangements of these characteristic functional switches in adenosine-A2AAR and apo-A2AAR.
