This paper reviews the progress made in understanding the mechanical behaviour of the biliary system. Gallstones and diseases of the biliary tract affect more than 10% of the adult population. The complications of gal...This paper reviews the progress made in understanding the mechanical behaviour of the biliary system. Gallstones and diseases of the biliary tract affect more than 10% of the adult population. The complications of gallstones, i.e. acute pancreatitis and obstructive jandice, can be lethal, and patients with acalculous gallbladder pain often pose diagnostic difficulties and undergo repeated ultrasound scans and oral cholecystograms. Moreover, surgery to remove the gallbladder in these patients, in an attempt to relieve the symptoms, gives variable results. Extensive research has been carried out to understand the physiological and pathological functions of the biliary system, but the mechanism of the pathogenesis of gallstones and pain production still remain poorly understood. It is believed that the mechanical factors play an essential role in the mechanisms of the gallstone formation and biliary diseases. However, despite the extensive literature in clinical studies, only limited work has been carried out to study the biliary system from the mechanical point of view. In this paper, we discuss the state of art knowledge of the fluid dynamics of bile flow in the biliary tract, the solid mechanics of the gallbladder and bile ducts, recent mathematical and numerical modelling of the system, and finally the future challenges in the area.展开更多
Colorectal cancer hepatic metastases represent the final stage of a multi-step biological process.This process starts with a series of mutations in colonic epithelial cells,continues with their detachment from the lar...Colorectal cancer hepatic metastases represent the final stage of a multi-step biological process.This process starts with a series of mutations in colonic epithelial cells,continues with their detachment from the large intestine,dissemination through the blood and/or lymphatic circulation,attachment to the hepatic sinusoids and interactions with the sinusoidal cells,such as sinusoidal endothelial cells,Kupffer cells,stellate cells and pit cells.The metastatic sequence terminates with colorectal cancer cell invasion,adaptation and colonisation of the hepatic parenchyma.All these events,termed the colorectal cancer invasion-metastasis cascade,include multiple molecular pathways,intercellular interactions and expression of a plethora of chemokines and growth factors,and adhesion molecules,such as the selectins,the integrins or the cadherins,as well as enzymes including matrix metalloproteinases.This review aims to present recent advances that provide insights into these cell-biological events and emphasizes those that may be amenable to therapeutic targeting.展开更多
Significant uncertainties remain regarding the temporal evolution of natural vegetation during the Quaternary, and drivers of past vegetation change, on the Chinese Loess Plateau （CLP）. This study presents analyses ...Significant uncertainties remain regarding the temporal evolution of natural vegetation during the Quaternary, and drivers of past vegetation change, on the Chinese Loess Plateau （CLP）. This study presents analyses of total organic carbon isotopic composition （TOC） and n-alkane ratios （C31/C27） from the Lingtai loess-palaeosol sequence on the central CLP over the last 450 kyr. The results demonstrate that the vegetation in this region comprised a mix of C3 and C4 plants of herb and woody growth-form. C3 plants dominated for most of the last 450 kyr, but this did not lead to extensive forest. C3 woody plants were more abundant in MIS9 （S3 period） and MIS5 （S 1 period） during warm and humid climate conditions. Herbs increased in the region since 130 kyr, possibly as a result of increased aridity. On the orbital timescales, there was a reduction of C3 herbal plants in MIS 11 （$4） than in M1S 12 （L5）, and in Holocene than in the last glacial period. Our isotope and n-alkane proxy records are in agreement with Artemisia pollen changes in the region, which is/was the dominant species in this area and varying due to different heat and water conditions between glacial and interglacial periods. Though the climate in MIS1 （SO） was similar to that in MIS11 （S4）, a significant increase in woody plants during the Holocene suggests the impact of human activities and ecological effects of changes in fire activity.展开更多
AIM: To describe the role of resistin in liver fibrosis. METHODS: For the in vivo animal study, Sprague Dawley rats were subjected to bile duct ligation (BDL) for 4 wk. Rat liver, adipose tissue (epididymal fat) and s...AIM: To describe the role of resistin in liver fibrosis. METHODS: For the in vivo animal study, Sprague Dawley rats were subjected to bile duct ligation (BDL) for 4 wk. Rat liver, adipose tissue (epididymal fat) and serum were analyzed for resistin expression. For the in vitro experiment, rat primary hepatic stellate cells (HSCs) and Kupffer cells (KCs) were used. HSCs were exposed to recombinant resistin, and collagenⅠ, transforming growth factor β1, α smooth muscle actin, tissue inhibitor of metalloproteinase 1 and connective tissue growth factor expression were analyzed. Resistin gene and protein expression was quantified as was the expression of pro-inflammatory cytokines including tumor necrosis factor α (TNFα), interleukin (IL)-1, IL-6, IL-8 and monocyte chemotactic protein-1 (MCP-1). The effects of resistin on HSC proliferation, migration and apoptosis were determined. The effects of resistin on KCs were also investigated. RESULTS: Following BDL, rat epididymal fat and serum rather than liver showed higher resistin expression compared to control rats. In liver, resistin was expressed in quiescent HSCs and KCs. Resistin treatment resulted in enhancement of TNFα , IL-6 , IL-8 and MCP-1 gene expression and increased IL-6 and MCP-1 protein in HSCs. Resistin activated HSC phospho-MAPK/p38, and p38 inhibition diminished IL-6 and MCP-1 expression. Furthermore, resistin facilitated HSC proliferation and migration, but decreased apoptosis which was via an IL-6 and MCP-1 mechanism. Finally, resistin-induced transforming growth factor β1 from KCs enhanced HSC collagenⅠexpression. CONCLUSION: Resistin directly and indirectly modulates HSC behavior towards a more pro-fibrogenic phenotype.展开更多
AIM To investigate and summarise the current evidence surrounding management of Bouveret's syndrome(BS).METHODS A MEDLINE search was performed for the BS. The search was conducted independently by two clinicians(Y...AIM To investigate and summarise the current evidence surrounding management of Bouveret's syndrome(BS).METHODS A MEDLINE search was performed for the BS. The search was conducted independently by two clinicians(Yahya ALHabbal and Matthew Ng) in April 2016. A case of BS is also described.RESULTS A total of 315 articles, published from 1967 to 2016, were found. For a clinically meaningful clinical review, articles published before 01/01/1990 and were excluded, leaving 235 unique articles to review. Twenty-seven articles were not available(neither by direct communication nor through inter-library transfer). These were also excluded. The final number of articles reviewed was 208. There were 161 case reports, 13 reviews, 23 images(radiological and clinical images), and 11 letters to editor. Female to male ratio was 1.82. Mean age was 74 years. Treatment modalities included laparotomy in the majority of cases, laparoscopic surgery, endoscopic surgery and shockwave lithotripsy.CONCLUSION There is limited evidence in the literature about the appropriate approach. We suggest an algorithm for management of BS.展开更多
This paper presents the formulation of finite elements based on Deslauriers-Dubuc interpolating scaling functions, also known as Interpolets, for their use in wave propagation modeling. Unlike other wavelet families l...This paper presents the formulation of finite elements based on Deslauriers-Dubuc interpolating scaling functions, also known as Interpolets, for their use in wave propagation modeling. Unlike other wavelet families like Daubechies, Interpolets possess rational filter coefficients, are smooth, symmetric and therefore more suitable for use in numerical methods. Expressions for stiffness and mass matrices are developed based on connection coefficients, which are inner products of basis functions and their derivatives. An example in 1-D was formulated using Central Difference and Newmark schemes for time differentiation. Encouraging results were obtained even for large time steps. Results obtained in 2-D are compared with the standard Finite Difference Method for validation.展开更多
Purpose: 1) To compare the survival of patients with colorectal liver metastases who underwent resection as the primary treatment against patients who had chemotherapy as the primary treatment. 2) To compare the survi...Purpose: 1) To compare the survival of patients with colorectal liver metastases who underwent resection as the primary treatment against patients who had chemotherapy as the primary treatment. 2) To compare the survival in patients with recurrent inoperable liver metastases (after resection) treated with Oxaliplatin or Irinotecan against those patients with inoperable recurrence who were treated with 5-FU. Patients and Methods: 538 patients with colorectal liver metastases were referred to our unit between November 1997 and May 2005;247 underwent liver resection and 291 had palliative chemotherapy. Results: Only 7.8% of non-operated patients survived for 5 years compared to 31.5% of the liver resection group. After surgery, 191 patients developed inoperable recurrent disease. These patients were treated with chemotherapy;Ox/Ir patients had a 3 year survival of 55% compared to 32% of those who received 5-FU. Our data shows that in patients who relapse after liver surgery, chemotherapy with Oxaliplatin or Irinotecan confers a significant survival benefit.展开更多
The presence of eclogites within continental crust is a key indicator of collisional orogenesis.Eclogites within the Eastern Glenelg basement inlier of the Northern Highland Terrane(NHT)have been redated in order to p...The presence of eclogites within continental crust is a key indicator of collisional orogenesis.Eclogites within the Eastern Glenelg basement inlier of the Northern Highland Terrane(NHT)have been redated in order to provide more accurate constraints on the timing of collision within the northern arm of the Grenville Orogen.The eclogites yield dates of ca.1200 Ma which are interpreted to record the onset of continent–continent interaction,and the NHT as a whole is thought to represent the lower plate in successive 1200–1000 Ma collision events.The Eastern Glenelg basement inlier is viewed as a fragment of the leading edge of the NHT continental basement that was partially subducted along a suture and then exhumed back up the subduction channel.Differences in ages of igneous protoliths and intrusive histories,and metamorphic events(this paper)between the NHT basement and the Laurentian foreland,suggests that they were separate crustal blocks until after ca.1600 Ma.We therefore suggest that:(1)the NHT represents a fragment of Archean–Paleoproterozoic crust that was reworked within the ca.1.7–1.6 Ga Labradorian-Gothian belt,although whether it was derived from Laurentia or Baltica is uncertain,and(2)amalgamation of the NHT with the Laurentian foreland did not occur until the terminal stages of the Grenville collision at ca.1000 Ma.展开更多
文摘This paper reviews the progress made in understanding the mechanical behaviour of the biliary system. Gallstones and diseases of the biliary tract affect more than 10% of the adult population. The complications of gallstones, i.e. acute pancreatitis and obstructive jandice, can be lethal, and patients with acalculous gallbladder pain often pose diagnostic difficulties and undergo repeated ultrasound scans and oral cholecystograms. Moreover, surgery to remove the gallbladder in these patients, in an attempt to relieve the symptoms, gives variable results. Extensive research has been carried out to understand the physiological and pathological functions of the biliary system, but the mechanism of the pathogenesis of gallstones and pain production still remain poorly understood. It is believed that the mechanical factors play an essential role in the mechanisms of the gallstone formation and biliary diseases. However, despite the extensive literature in clinical studies, only limited work has been carried out to study the biliary system from the mechanical point of view. In this paper, we discuss the state of art knowledge of the fluid dynamics of bile flow in the biliary tract, the solid mechanics of the gallbladder and bile ducts, recent mathematical and numerical modelling of the system, and finally the future challenges in the area.
文摘Colorectal cancer hepatic metastases represent the final stage of a multi-step biological process.This process starts with a series of mutations in colonic epithelial cells,continues with their detachment from the large intestine,dissemination through the blood and/or lymphatic circulation,attachment to the hepatic sinusoids and interactions with the sinusoidal cells,such as sinusoidal endothelial cells,Kupffer cells,stellate cells and pit cells.The metastatic sequence terminates with colorectal cancer cell invasion,adaptation and colonisation of the hepatic parenchyma.All these events,termed the colorectal cancer invasion-metastasis cascade,include multiple molecular pathways,intercellular interactions and expression of a plethora of chemokines and growth factors,and adhesion molecules,such as the selectins,the integrins or the cadherins,as well as enzymes including matrix metalloproteinases.This review aims to present recent advances that provide insights into these cell-biological events and emphasizes those that may be amenable to therapeutic targeting.
基金supported by the National Natural Science Foundation of China(Grant No.41172149)the Science Fund for Creative Research Groups of NSFC(Grant No.41321062)the National Key Basic Research Program of China(Grant No.2015CB953804)
文摘Significant uncertainties remain regarding the temporal evolution of natural vegetation during the Quaternary, and drivers of past vegetation change, on the Chinese Loess Plateau （CLP）. This study presents analyses of total organic carbon isotopic composition （TOC） and n-alkane ratios （C31/C27） from the Lingtai loess-palaeosol sequence on the central CLP over the last 450 kyr. The results demonstrate that the vegetation in this region comprised a mix of C3 and C4 plants of herb and woody growth-form. C3 plants dominated for most of the last 450 kyr, but this did not lead to extensive forest. C3 woody plants were more abundant in MIS9 （S3 period） and MIS5 （S 1 period） during warm and humid climate conditions. Herbs increased in the region since 130 kyr, possibly as a result of increased aridity. On the orbital timescales, there was a reduction of C3 herbal plants in MIS 11 （$4） than in M1S 12 （L5）, and in Holocene than in the last glacial period. Our isotope and n-alkane proxy records are in agreement with Artemisia pollen changes in the region, which is/was the dominant species in this area and varying due to different heat and water conditions between glacial and interglacial periods. Though the climate in MIS1 （SO） was similar to that in MIS11 （S4）, a significant increase in woody plants during the Holocene suggests the impact of human activities and ecological effects of changes in fire activity.
文摘AIM: To describe the role of resistin in liver fibrosis. METHODS: For the in vivo animal study, Sprague Dawley rats were subjected to bile duct ligation (BDL) for 4 wk. Rat liver, adipose tissue (epididymal fat) and serum were analyzed for resistin expression. For the in vitro experiment, rat primary hepatic stellate cells (HSCs) and Kupffer cells (KCs) were used. HSCs were exposed to recombinant resistin, and collagenⅠ, transforming growth factor β1, α smooth muscle actin, tissue inhibitor of metalloproteinase 1 and connective tissue growth factor expression were analyzed. Resistin gene and protein expression was quantified as was the expression of pro-inflammatory cytokines including tumor necrosis factor α (TNFα), interleukin (IL)-1, IL-6, IL-8 and monocyte chemotactic protein-1 (MCP-1). The effects of resistin on HSC proliferation, migration and apoptosis were determined. The effects of resistin on KCs were also investigated. RESULTS: Following BDL, rat epididymal fat and serum rather than liver showed higher resistin expression compared to control rats. In liver, resistin was expressed in quiescent HSCs and KCs. Resistin treatment resulted in enhancement of TNFα , IL-6 , IL-8 and MCP-1 gene expression and increased IL-6 and MCP-1 protein in HSCs. Resistin activated HSC phospho-MAPK/p38, and p38 inhibition diminished IL-6 and MCP-1 expression. Furthermore, resistin facilitated HSC proliferation and migration, but decreased apoptosis which was via an IL-6 and MCP-1 mechanism. Finally, resistin-induced transforming growth factor β1 from KCs enhanced HSC collagenⅠexpression. CONCLUSION: Resistin directly and indirectly modulates HSC behavior towards a more pro-fibrogenic phenotype.
文摘AIM To investigate and summarise the current evidence surrounding management of Bouveret's syndrome(BS).METHODS A MEDLINE search was performed for the BS. The search was conducted independently by two clinicians(Yahya ALHabbal and Matthew Ng) in April 2016. A case of BS is also described.RESULTS A total of 315 articles, published from 1967 to 2016, were found. For a clinically meaningful clinical review, articles published before 01/01/1990 and were excluded, leaving 235 unique articles to review. Twenty-seven articles were not available(neither by direct communication nor through inter-library transfer). These were also excluded. The final number of articles reviewed was 208. There were 161 case reports, 13 reviews, 23 images(radiological and clinical images), and 11 letters to editor. Female to male ratio was 1.82. Mean age was 74 years. Treatment modalities included laparotomy in the majority of cases, laparoscopic surgery, endoscopic surgery and shockwave lithotripsy.CONCLUSION There is limited evidence in the literature about the appropriate approach. We suggest an algorithm for management of BS.
文摘This paper presents the formulation of finite elements based on Deslauriers-Dubuc interpolating scaling functions, also known as Interpolets, for their use in wave propagation modeling. Unlike other wavelet families like Daubechies, Interpolets possess rational filter coefficients, are smooth, symmetric and therefore more suitable for use in numerical methods. Expressions for stiffness and mass matrices are developed based on connection coefficients, which are inner products of basis functions and their derivatives. An example in 1-D was formulated using Central Difference and Newmark schemes for time differentiation. Encouraging results were obtained even for large time steps. Results obtained in 2-D are compared with the standard Finite Difference Method for validation.
文摘Purpose: 1) To compare the survival of patients with colorectal liver metastases who underwent resection as the primary treatment against patients who had chemotherapy as the primary treatment. 2) To compare the survival in patients with recurrent inoperable liver metastases (after resection) treated with Oxaliplatin or Irinotecan against those patients with inoperable recurrence who were treated with 5-FU. Patients and Methods: 538 patients with colorectal liver metastases were referred to our unit between November 1997 and May 2005;247 underwent liver resection and 291 had palliative chemotherapy. Results: Only 7.8% of non-operated patients survived for 5 years compared to 31.5% of the liver resection group. After surgery, 191 patients developed inoperable recurrent disease. These patients were treated with chemotherapy;Ox/Ir patients had a 3 year survival of 55% compared to 32% of those who received 5-FU. Our data shows that in patients who relapse after liver surgery, chemotherapy with Oxaliplatin or Irinotecan confers a significant survival benefit.
文摘The presence of eclogites within continental crust is a key indicator of collisional orogenesis.Eclogites within the Eastern Glenelg basement inlier of the Northern Highland Terrane(NHT)have been redated in order to provide more accurate constraints on the timing of collision within the northern arm of the Grenville Orogen.The eclogites yield dates of ca.1200 Ma which are interpreted to record the onset of continent–continent interaction,and the NHT as a whole is thought to represent the lower plate in successive 1200–1000 Ma collision events.The Eastern Glenelg basement inlier is viewed as a fragment of the leading edge of the NHT continental basement that was partially subducted along a suture and then exhumed back up the subduction channel.Differences in ages of igneous protoliths and intrusive histories,and metamorphic events(this paper)between the NHT basement and the Laurentian foreland,suggests that they were separate crustal blocks until after ca.1600 Ma.We therefore suggest that:(1)the NHT represents a fragment of Archean–Paleoproterozoic crust that was reworked within the ca.1.7–1.6 Ga Labradorian-Gothian belt,although whether it was derived from Laurentia or Baltica is uncertain,and(2)amalgamation of the NHT with the Laurentian foreland did not occur until the terminal stages of the Grenville collision at ca.1000 Ma.
