1病例介绍患者女,57岁。因“左腕部肿物注射药物治疗后左手发白、麻木、疼痛2h余”于2022年3月24日急诊入院。患者因左腕部肿物于当日在外院诊断为“左腕部腱鞘囊肿”,并给予囊肿穿刺抽吸、注射药物(约3 m L硬化剂聚桂醇)治疗;药物注射...1病例介绍患者女,57岁。因“左腕部肿物注射药物治疗后左手发白、麻木、疼痛2h余”于2022年3月24日急诊入院。患者因左腕部肿物于当日在外院诊断为“左腕部腱鞘囊肿”,并给予囊肿穿刺抽吸、注射药物(约3 m L硬化剂聚桂醇)治疗;药物注射完毕拔除注射器后即出现左手颜色苍白、麻木、疼痛不适。观察约1 h后症状仍无明显改善,遂入我院进一步诊治。展开更多
Portal hypertension is a common clinical syndrome, defined by a pathologic increase in the portal venous pressure. Increased resistance to portal blood flow, the primary factor in the pathophysiology of portal hyperte...Portal hypertension is a common clinical syndrome, defined by a pathologic increase in the portal venous pressure. Increased resistance to portal blood flow, the primary factor in the pathophysiology of portal hypertension, is in part due to morphological changes occurring in chronic liver diseases. This results in rerouting of blood flow away from the liver through collateral pathways to low-pressure systemic veins. Through a variety of computed tomographic, sonographic, magnetic resonance imaging and angiographic examples, this article discusses the appearances and prevalence of both common and less common portosystemic collateral channels in the thorax and abdomen. A brief overview of established interventional radiologic techniques for treatment of portal hypertension will also be provided. Awareness of the various imaging manifestations of portal hypertension can be helpful for assessing overall prognosis and planning proper management.展开更多
Quantitative structure-retention relationship (QSRR) model for the estimation of retention indices (RIs) of 39 oxygen-containing compounds containing ketones and esters was established by our newly introduced dist...Quantitative structure-retention relationship (QSRR) model for the estimation of retention indices (RIs) of 39 oxygen-containing compounds containing ketones and esters was established by our newly introduced distance-based atom-type indices DAI. The useful application of the novel DAI indices has been demonstrated by developing accurate predictive equations for gas chromatographic retention indices. The statistical results of the multiple linear regression for the final model are τ=0.9973 and s=8.23. Furthermore, an external test set of 10 oxo-containing compounds can be accurately predicted with the final equation giving the following statistical results: τpred:0.9966 and spred=8.56.展开更多
AIM:To evaluate the management of pancreaticopleural fistulas involving early endoscopic instrumentation of the pancreatic duct.METHODS:Eight patients with a spontaneous pancre-aticopleural fistula underwent endoscopi...AIM:To evaluate the management of pancreaticopleural fistulas involving early endoscopic instrumentation of the pancreatic duct.METHODS:Eight patients with a spontaneous pancre-aticopleural fistula underwent endoscopic retrograde cholang iopancreatography(ERCP) with an intentionto stent the site of a ductal disruption as the primarytreatment. Imaging features and management were evaluated retrospectively and compared with outcome.RESULTS:In one case,the stent bridged the site of aductal disruption. The fistula in this patient closed with in3 wk. The main pancreatic duct in this case appearednormal,except for a leak located in the body of the pancreas. In another patient,the papilla of Vater couldnot be found and cannulation of the pancreatic ductfailed. This patient underwent surgical treatment. In the remaining 6 cases,it was impossible to insert a stentinto the main pancreatic duct properly so as to coverthe site of leakage or traverse a stenosis situated down-stream to the fistula. The placement of the stent failed because intraductal stones(n = 2) and ductal strictures(n = 2) precluded its passage or the stent was too short to reach the fistula located in the distal part of the pancreas(n = 2) . In 3 out of these 6 patients,the pancre-aticopleural fistula closed on further medical treatment.In these cases,the main pancreatic duct was normalor only mildly dilated,and there was a leakage at the body/tail of the pancreas. In one of these 3 patients,additional percutaneous drainage of the peripancre atic fluid collections allowed better control of the leakageand facilitated resolution of the fistula. The remaining3 patients had a tight stenosis of the main pancreatic duct resistible to dilatation and the stent could not beinserted across the stenosis. Subsequent conservative treatment proved unsuccessful in these patients. Aftera failed the rapeutic ERCP,3 patients in our series developed superinfection of the pleural or peripancreatic fluid collections. Four out of 8 patients in our series required subsequent surgery due to a failed non-operative treat-ment. Distal pancreatectomy with splenectomy was performed in 3 cases. In one case,only external drainage of the pancreatic pseudocyst was done because of diffuse peripancreatic inflammatory infiltration precluding safe dissection. There were no perioperative mortalities.There was no recurrence of a pancreati copleural fistulain any of the patients.CONCLUSION:Optimal management of pancreaticopleural fistulas requires appropriate patient selection that should be based on the underlying pancreatic ductab normalities.展开更多
Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently ...Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.展开更多
For an arbitrary tensor(multi-index array) with linear constraints at each direction,it is proved that the factors of any minimal canonical tensor approximation to this tensor satisfy the same linear constraints for t...For an arbitrary tensor(multi-index array) with linear constraints at each direction,it is proved that the factors of any minimal canonical tensor approximation to this tensor satisfy the same linear constraints for the corresponding directions.展开更多
The spatial and temporal changes of landscape pattern and their driving forces in each functional zone of Nanling National Nature Reserve were analyzed based on the GIS and RS platform. The results showed that from 19...The spatial and temporal changes of landscape pattern and their driving forces in each functional zone of Nanling National Nature Reserve were analyzed based on the GIS and RS platform. The results showed that from 1988 to 2009, in respect of changes of Jandscape area, the main forest landscape accounted about 95% of the total area, of which evergreen broad-leaved forest had the largest area, accounting for more than 50% of the total area. The dominant landscape was coniferous forest. In respect of landscape fragmentation, the density index of land- scape in the whole area increased, and the degree of landscape fragmentation also increased. In the core area, the patch density decreased slightly, and the average patch area of each type of landscape increased; the degree of landscape fragmen- tation increased slightly. In the buffer area and the experimental area, the degree of landscape fragmentation increased. In terms of landscape diversity, the landscape pattern in the whole area became complex, and the diversity index of landscape in- creased and the degree of heterogeneity increased. In the core area, the diversity index of landscape increased slightly. In the buffer area, it increased significantly. In the experiment area, the diversity index reduced, and the degree of landscape het- erogeneity reduced. In the whole study area, the landscape tended to be diversified. The landscape pattern of the experimental area was consistent with that of the whole study area, and there was no obvious change in the buffer zone, while the landscape pattern in the core area developed towards the single direction.展开更多
In this paper we generalize the aggregated premium income process from a constant rate process to a poisson process for the classical compound Poinsson risk model,then for the generalized model and the classical compo...In this paper we generalize the aggregated premium income process from a constant rate process to a poisson process for the classical compound Poinsson risk model,then for the generalized model and the classical compound poisson risk model ,we respectively get its survival probability in finite time period in case of exponential claim amounts.展开更多
AIM: To clarify the innervation of the antro-pyloric region in humans from a clinico-anatomical perspective. METHODS: The stomach, duodenum and surrounding structures were dissected in 10 cadavers, and immersed in a...AIM: To clarify the innervation of the antro-pyloric region in humans from a clinico-anatomical perspective. METHODS: The stomach, duodenum and surrounding structures were dissected in 10 cadavers, and immersed in a 10mg/L solution of alizarin red S in ethanol to stain the peripheral nerves. The distribution details were studied to confirm innervations in the above areas using a binocular microscope. Similarly, innervations in 10 Suncus murinus were examined using the method of whole-mount imm unohistochemistry. RESULTS: The innervation of the pyloric region in humans involved three routes: One arose from the anterior hepatic plexus via the route of the suprapyloric/supraduodenal branch of the right gastric artery; the second arose from the anterior and posterior gastric divisions, and the third originated from the posterior-lower region of the pyloric region, which passed via the infrapyloric artery or retroduodenal branches and was related to the gastroduodenal artery and right gastroepiploic artery. For Suncus murinus, results similar to those in humans were observed. CONCLUSION: There are three routes of innervation of the pyloric region in humans, wherein the route of the right gastric artery is most important for preserving pyloric region innervation. Function will be preserved by more than 80% by preserving the artery in pylorus-preserving pancreaticoduodenectomy (PPPD). However, the route of the infrapyloric artery should not be disregarded. This route is related to several arteries (the right gastroepiploic and gastroduodenal arteries), and the preserving of these arteries is advantageous for preserving pyloric innervation in PPPD. Concurrently, the nerves of Latarjet also play an important role in maintaining innervation of the antro-pyloric region in PPPD. This is why pyloric function is not damaged in some patients when the right gastric artery is dissected or damaged in PPPD.展开更多
Fingerprint segmentation is an important step in fingerprint recognition and is usually aimed to identify non-ridge regions and unrecoverable low quality ridge regions and exclude them as background so as to reduce th...Fingerprint segmentation is an important step in fingerprint recognition and is usually aimed to identify non-ridge regions and unrecoverable low quality ridge regions and exclude them as background so as to reduce the time expenditure of image processing and avoid detecting false features. In high and in low quality ridge regions, often are some remaining ridges which are the afterimages of the previously scanned finger and are expected to be excluded from the foreground. However, existing seg-mentation methods generally do not take the case into consideration, and often, the remaining ridge regions are falsely classified as foreground by segmentation algorithm with spurious features produced erroneously including unrecoverable regions as fore-ground. This paper proposes two steps for fingerprint segmentation aimed at removing the remaining ridge region from the fore-ground. The non-ridge regions and unrecoverable low quality ridge regions are removed as background in the first step, and then the foreground produced by the first step is further analyzed for possible remove of the remaining ridge region. The proposed method proved effective in avoiding detecting false ridges and in improving minutiae detection.展开更多
Abstract Inter-simple sequence repeat (ISSR) markers were used to determine the genetic variation and genetic differentiation of cultured and wild populations of Trachidermus fasciatus, an endangered catadromous fis...Abstract Inter-simple sequence repeat (ISSR) markers were used to determine the genetic variation and genetic differentiation of cultured and wild populations of Trachidermus fasciatus, an endangered catadromous fish species in China. Six selected primers were used to amplify DNA samples from 85 individuals, and 353 loci were detected. Relatively low genetic diversity was detected in the cultured population (the percentage of polymorphic loci PPL=73.80%, Nei's gene diversity h--0.178 2, Shannon information index I=0.276 9). However, the genetic diversity at the species level was relatively high (PPL-91.78%; h = 0.258 3, I= 0.398 6). The UPGMA tree grouped together the genotypes almost according to their cultured and wild origin, showing distinct differences in genetic structure between wild and cultured populations. The pairwise F^t values confirmed significant genetic differentiation between wild and cultured samples. The cultivated population seems to be low in genetic diversity as a result of detrimental genetic effects in the captive population. The results suggest that ISSR markers are effective for rapid assessment of the degree of diversity of a population, thus giving important topical information relevant to preserving endangered species.展开更多
The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixin...The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixing small watershed of the low mountain and hilly region of Jilin Province,Northeast China.This study aims to elucidate the effects of soil and water conservation practices on soil conditions after the short-term implementation of practices.Soil samples were collected from five soil and water conservation sites(ER,FP,FR,SS,and VR)and two controls(BL and CT)to investigate their properties.To evaluate the influence of soil and water conservation practices on soil quality,an integrated quantitative index,soil quality index(QI),was developed to compare the soil quality under the different soil and water conservation practices.The results show that not all soil and water conservation practices can improve the soil conditions and not all soil properties,especially soil organic carbon(SOC),can be recovered under soil and water conservation practice in short-term.Moreover,the QI in the five soil and water conservation practices and two controls was in the following order:ER>VR>BL>FR>CT>SS>FP.ER exhibited a higher soil quality value on a slope scale.In the low mountain and hilly region of Northeast China,ER is a better choice than the conversion of farmlands to planted grasslands and woodlands early in the soil and water conservation program.展开更多
The highway construction inevitably may cause certain influence to the cultural heritage and the natural environment along the route, particularly in design stage; if the route selection is unreasonable, it will certa...The highway construction inevitably may cause certain influence to the cultural heritage and the natural environment along the route, particularly in design stage; if the route selection is unreasonable, it will certainly impact the natural resource seriously along the route. On the contrary, good design can reasonably develop, use, protect and promote the value of cultural heritage and natural environment. Changsha to Jishou (Chang-Ji) freeway is one section of Changsha to Chongqing freeway, which is one of the eight big west channels as planned in China; two cities of Changde and Huaihua and one autonomous region of Xianxi in western Hunan province, along which the cultural heritage and the natural resource are rich, and the natural landscape is exquisite. This paper investigates and analyzes the natural resources along the route of Chang-Ji freeway, puts forward some protection design evaluation indexes for mountain area freeway by the thought of context sensitive design. At last, the paper introduces the effect of applying the indexes to select route of Chang-Ji freeway.展开更多
We studied diatom distribution from 62 samples from the uppermost 1 cm of sedimem in the South China Sea (SCS), using grabs or box corers in three cruises between 2001-2007. Fifty six genera, 256 species and their v...We studied diatom distribution from 62 samples from the uppermost 1 cm of sedimem in the South China Sea (SCS), using grabs or box corers in three cruises between 2001-2007. Fifty six genera, 256 species and their varieties were identified. Dominating species included Coscinodiscus africanus, Coscinodiscus nodulifer, Cyclotella stylorum, Hemidiscus cuneiformis, Melosira sulcata, Nitzschia marina, Roperia tesselata, Thalassionema nitzschioides, Thalassiosira excentrica, and Thalassiothrix longissima. Most surface sediments in the SCS were rich ill diatoms, except for a few coarse samples. Average diatom abundance in the study area was 104 607 valve/g. In terms of the abundance, ecology, and spatial distribution, seven diatom zones (Zones 1-7) were recognized. Zone 1 (northern continental shelf) is affected by warm currents, SCS northern branch of the Kuroshio, and northern coastal currents; Zone 2 (northwestern continental shelf) is affected by intense coastal currents; Zone 3 (Xisha Islands sea area) is a bathyal environment with transitional water masses; Zone 4 (sea basin) is a bathyal-to-deep sea with stable and uniform central water masses in a semi-enclosed marginal sea; Zone 5 (Nansba Islands marine area) is a pelagic environment with relatively high surface temperature; Zone 6 (northern Sunda Shelf) is a tropical shelf environment; and Zone 7 (northern Kalimantan Island shelf area) is affected by warm waters from the Indian Ocean and coastal waters. The data indicate that these diatom zones are closely related to topography, hydrodynamics, temperature, nutrients and especially the salinity. Better understanding of the relationship between diatom distribution and the oceanographic factors would help in the reconstruction of the SCS in the past.展开更多
Venous complications in patients with acute pancreatitis typically occur as a form of splenic,portal,or superior mesenteric vein thrombosis and have been detected more frequently in recent reports.Although a well-orga...Venous complications in patients with acute pancreatitis typically occur as a form of splenic,portal,or superior mesenteric vein thrombosis and have been detected more frequently in recent reports.Although a well-organized protocol for the treatment of venous thrombosis has not been established,anticoagulation therapy is commonly recommended.A 73-year-old man was diagnosed with acute progressive portal vein thrombosis associated with acute pancreatitis.After one month of anticoagulation therapy,the patient developed severe hematemesis.With endoscopy and an abdominal computed tomography scan,hemorrhages in the pancreatic pseudocyst,which was ruptured into the duodenal bulb,were confirmed.After conservative treatment,the patient was stabilized.While the rupture of a pseudocyst into the surrounding viscera is a well-known phenomenon,spontaneous rupture into the duodenum is rare.Moreover,no reports of upper gastrointestinal bleeding caused by pseudocyst rupture in patients under anticoagulation therapy for venous thrombosis associated with acute pancreatitis have been published.Herein,we report a unique case of massive upper gastrointestinal bleeding due to pancreatic pseudocyst rupture into the duodenum,which developed during anticoagulation therapy for portal vein thrombosis associated with acute pancreatitis.展开更多
AIM:To evaluate the impact of surgical volume on nationwide hospital mortality after pancreaticoduodenectomy(PD) for periampullary tumors in South Korea.METHODS:Periampullary cancer patients who underwent PD between 2...AIM:To evaluate the impact of surgical volume on nationwide hospital mortality after pancreaticoduodenectomy(PD) for periampullary tumors in South Korea.METHODS:Periampullary cancer patients who underwent PD between 2005 and 2008 were analyzed from the database of the Health Insurance Review and Assessment Service of South Korea.A total of 126 hospitals were divided into 5 categories,each similar in terms of surgical volume for each category.We used hospital mortality as a quality indicator,which was defined as death during the hospital stay for PD,and calculated adjusted mortality through multivariate logistic models using several confounder variables.RESULTS:A total of eligible 4975 patients were enrolled in this study.Average annual surgical volume of hospitals was markedly varied,ranging from 215 PDs in the very-high-volume hospital to < 10 PDs in the verylow-volume hospitals.Admission route,type of medical security,and type of operation were significantly different by surgical volume.The overall hospital mortality was 2.1% and the observed hospital mortality by surgical volume showed statistical difference.Surgical volume,age,and type of operation were independent risk factors for hospital death,and adjusted hospital mortality showed a similar difference between hospitals with observed mortality.The result of the HosmerLemeshow test was 5.76(P = 0.674),indicating an acceptable appropriateness of our regression model.CONCLUSION:The higher-volume hospitals showed lower hospital mortality than the lower-volume hospitals after PD in South Korea,which were clarified through the nationwide database.展开更多
As the protected areas of land and coastal environment, nature reserves are designed to address how to reconcile the conservation of biodiversity, the quest for economic and social development and the maintenance of c...As the protected areas of land and coastal environment, nature reserves are designed to address how to reconcile the conservation of biodiversity, the quest for economic and social development and the maintenance of cultural values. This paper establishes a framework for nature reserve development that seeks to incorporate ecotourism into its strategies. The overall purpose was to identify the information needs required for a comprehensive nature reserve that incorporates ecotourism related values. It also illustrates the utility of this framework in the context of the Wuzhishan Mountain Region of China. A literature review, the first phase of a visionary strategy and a subsequent gap analysis for available management information were undertaken in order to achieve this paper's purpose. Finally, recommendations axe pre-sented for integrating ecotourism into nature reserve development in the Wuzhishan Mountain Region.展开更多
文摘1病例介绍患者女,57岁。因“左腕部肿物注射药物治疗后左手发白、麻木、疼痛2h余”于2022年3月24日急诊入院。患者因左腕部肿物于当日在外院诊断为“左腕部腱鞘囊肿”,并给予囊肿穿刺抽吸、注射药物(约3 m L硬化剂聚桂醇)治疗;药物注射完毕拔除注射器后即出现左手颜色苍白、麻木、疼痛不适。观察约1 h后症状仍无明显改善,遂入我院进一步诊治。
文摘Portal hypertension is a common clinical syndrome, defined by a pathologic increase in the portal venous pressure. Increased resistance to portal blood flow, the primary factor in the pathophysiology of portal hypertension, is in part due to morphological changes occurring in chronic liver diseases. This results in rerouting of blood flow away from the liver through collateral pathways to low-pressure systemic veins. Through a variety of computed tomographic, sonographic, magnetic resonance imaging and angiographic examples, this article discusses the appearances and prevalence of both common and less common portosystemic collateral channels in the thorax and abdomen. A brief overview of established interventional radiologic techniques for treatment of portal hypertension will also be provided. Awareness of the various imaging manifestations of portal hypertension can be helpful for assessing overall prognosis and planning proper management.
文摘Quantitative structure-retention relationship (QSRR) model for the estimation of retention indices (RIs) of 39 oxygen-containing compounds containing ketones and esters was established by our newly introduced distance-based atom-type indices DAI. The useful application of the novel DAI indices has been demonstrated by developing accurate predictive equations for gas chromatographic retention indices. The statistical results of the multiple linear regression for the final model are τ=0.9973 and s=8.23. Furthermore, an external test set of 10 oxo-containing compounds can be accurately predicted with the final equation giving the following statistical results: τpred:0.9966 and spred=8.56.
文摘AIM:To evaluate the management of pancreaticopleural fistulas involving early endoscopic instrumentation of the pancreatic duct.METHODS:Eight patients with a spontaneous pancre-aticopleural fistula underwent endoscopic retrograde cholang iopancreatography(ERCP) with an intentionto stent the site of a ductal disruption as the primarytreatment. Imaging features and management were evaluated retrospectively and compared with outcome.RESULTS:In one case,the stent bridged the site of aductal disruption. The fistula in this patient closed with in3 wk. The main pancreatic duct in this case appearednormal,except for a leak located in the body of the pancreas. In another patient,the papilla of Vater couldnot be found and cannulation of the pancreatic ductfailed. This patient underwent surgical treatment. In the remaining 6 cases,it was impossible to insert a stentinto the main pancreatic duct properly so as to coverthe site of leakage or traverse a stenosis situated down-stream to the fistula. The placement of the stent failed because intraductal stones(n = 2) and ductal strictures(n = 2) precluded its passage or the stent was too short to reach the fistula located in the distal part of the pancreas(n = 2) . In 3 out of these 6 patients,the pancre-aticopleural fistula closed on further medical treatment.In these cases,the main pancreatic duct was normalor only mildly dilated,and there was a leakage at the body/tail of the pancreas. In one of these 3 patients,additional percutaneous drainage of the peripancre atic fluid collections allowed better control of the leakageand facilitated resolution of the fistula. The remaining3 patients had a tight stenosis of the main pancreatic duct resistible to dilatation and the stent could not beinserted across the stenosis. Subsequent conservative treatment proved unsuccessful in these patients. Aftera failed the rapeutic ERCP,3 patients in our series developed superinfection of the pleural or peripancreatic fluid collections. Four out of 8 patients in our series required subsequent surgery due to a failed non-operative treat-ment. Distal pancreatectomy with splenectomy was performed in 3 cases. In one case,only external drainage of the pancreatic pseudocyst was done because of diffuse peripancreatic inflammatory infiltration precluding safe dissection. There were no perioperative mortalities.There was no recurrence of a pancreati copleural fistulain any of the patients.CONCLUSION:Optimal management of pancreaticopleural fistulas requires appropriate patient selection that should be based on the underlying pancreatic ductab normalities.
文摘Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.
基金supported by the Russian Fund for Basic Research (RFBR grant 08-01-00115,RFBR/DFG grant 09-01-91332,RFBR grant 09-01-12058)Priority Research Programme of Department of Mathematical Sciences of Russian Academy of Sciences
文摘For an arbitrary tensor(multi-index array) with linear constraints at each direction,it is proved that the factors of any minimal canonical tensor approximation to this tensor satisfy the same linear constraints for the corresponding directions.
文摘The spatial and temporal changes of landscape pattern and their driving forces in each functional zone of Nanling National Nature Reserve were analyzed based on the GIS and RS platform. The results showed that from 1988 to 2009, in respect of changes of Jandscape area, the main forest landscape accounted about 95% of the total area, of which evergreen broad-leaved forest had the largest area, accounting for more than 50% of the total area. The dominant landscape was coniferous forest. In respect of landscape fragmentation, the density index of land- scape in the whole area increased, and the degree of landscape fragmentation also increased. In the core area, the patch density decreased slightly, and the average patch area of each type of landscape increased; the degree of landscape fragmen- tation increased slightly. In the buffer area and the experimental area, the degree of landscape fragmentation increased. In terms of landscape diversity, the landscape pattern in the whole area became complex, and the diversity index of landscape in- creased and the degree of heterogeneity increased. In the core area, the diversity index of landscape increased slightly. In the buffer area, it increased significantly. In the experiment area, the diversity index reduced, and the degree of landscape het- erogeneity reduced. In the whole study area, the landscape tended to be diversified. The landscape pattern of the experimental area was consistent with that of the whole study area, and there was no obvious change in the buffer zone, while the landscape pattern in the core area developed towards the single direction.
基金Supported by the Natural Science Foundation of China(10071019)
文摘In this paper we generalize the aggregated premium income process from a constant rate process to a poisson process for the classical compound Poinsson risk model,then for the generalized model and the classical compound poisson risk model ,we respectively get its survival probability in finite time period in case of exponential claim amounts.
基金Supported by Ministry of Education, Culture, Sports, Science and Technology of Japan Grant, No. 14570008
文摘AIM: To clarify the innervation of the antro-pyloric region in humans from a clinico-anatomical perspective. METHODS: The stomach, duodenum and surrounding structures were dissected in 10 cadavers, and immersed in a 10mg/L solution of alizarin red S in ethanol to stain the peripheral nerves. The distribution details were studied to confirm innervations in the above areas using a binocular microscope. Similarly, innervations in 10 Suncus murinus were examined using the method of whole-mount imm unohistochemistry. RESULTS: The innervation of the pyloric region in humans involved three routes: One arose from the anterior hepatic plexus via the route of the suprapyloric/supraduodenal branch of the right gastric artery; the second arose from the anterior and posterior gastric divisions, and the third originated from the posterior-lower region of the pyloric region, which passed via the infrapyloric artery or retroduodenal branches and was related to the gastroduodenal artery and right gastroepiploic artery. For Suncus murinus, results similar to those in humans were observed. CONCLUSION: There are three routes of innervation of the pyloric region in humans, wherein the route of the right gastric artery is most important for preserving pyloric region innervation. Function will be preserved by more than 80% by preserving the artery in pylorus-preserving pancreaticoduodenectomy (PPPD). However, the route of the infrapyloric artery should not be disregarded. This route is related to several arteries (the right gastroepiploic and gastroduodenal arteries), and the preserving of these arteries is advantageous for preserving pyloric innervation in PPPD. Concurrently, the nerves of Latarjet also play an important role in maintaining innervation of the antro-pyloric region in PPPD. This is why pyloric function is not damaged in some patients when the right gastric artery is dissected or damaged in PPPD.
基金Project supported by the National Natural Science Foundation of China (No. 60373023), and the Science and Technology Research Foundation of Hunan City University (No. 20057306), China
文摘Fingerprint segmentation is an important step in fingerprint recognition and is usually aimed to identify non-ridge regions and unrecoverable low quality ridge regions and exclude them as background so as to reduce the time expenditure of image processing and avoid detecting false features. In high and in low quality ridge regions, often are some remaining ridges which are the afterimages of the previously scanned finger and are expected to be excluded from the foreground. However, existing seg-mentation methods generally do not take the case into consideration, and often, the remaining ridge regions are falsely classified as foreground by segmentation algorithm with spurious features produced erroneously including unrecoverable regions as fore-ground. This paper proposes two steps for fingerprint segmentation aimed at removing the remaining ridge region from the fore-ground. The non-ridge regions and unrecoverable low quality ridge regions are removed as background in the first step, and then the foreground produced by the first step is further analyzed for possible remove of the remaining ridge region. The proposed method proved effective in avoiding detecting false ridges and in improving minutiae detection.
基金Supported by the Key Laboratory of Freshwater Biodiversity Conservation and Utilization, Ministry of Agriculture (No. LFBCU0713)the Special Research Foundation for Public Welfare Marine Program (No. 200905019-2)
文摘Abstract Inter-simple sequence repeat (ISSR) markers were used to determine the genetic variation and genetic differentiation of cultured and wild populations of Trachidermus fasciatus, an endangered catadromous fish species in China. Six selected primers were used to amplify DNA samples from 85 individuals, and 353 loci were detected. Relatively low genetic diversity was detected in the cultured population (the percentage of polymorphic loci PPL=73.80%, Nei's gene diversity h--0.178 2, Shannon information index I=0.276 9). However, the genetic diversity at the species level was relatively high (PPL-91.78%; h = 0.258 3, I= 0.398 6). The UPGMA tree grouped together the genotypes almost according to their cultured and wild origin, showing distinct differences in genetic structure between wild and cultured populations. The pairwise F^t values confirmed significant genetic differentiation between wild and cultured samples. The cultivated population seems to be low in genetic diversity as a result of detrimental genetic effects in the captive population. The results suggest that ISSR markers are effective for rapid assessment of the degree of diversity of a population, thus giving important topical information relevant to preserving endangered species.
基金Under the auspices of Foundation of State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau(No.10501-1210)National Natural Science Foundation of China(No.31101606)+1 种基金Basic Scientific Research Operating Expenses of Jilin University(No.200903377)National Key Projects in National Science&Technology Program during the 12th Five-Year Plan Period of China(No.2011BAD16B10-3,2012BAD04B02-3)
文摘The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixing small watershed of the low mountain and hilly region of Jilin Province,Northeast China.This study aims to elucidate the effects of soil and water conservation practices on soil conditions after the short-term implementation of practices.Soil samples were collected from five soil and water conservation sites(ER,FP,FR,SS,and VR)and two controls(BL and CT)to investigate their properties.To evaluate the influence of soil and water conservation practices on soil quality,an integrated quantitative index,soil quality index(QI),was developed to compare the soil quality under the different soil and water conservation practices.The results show that not all soil and water conservation practices can improve the soil conditions and not all soil properties,especially soil organic carbon(SOC),can be recovered under soil and water conservation practice in short-term.Moreover,the QI in the five soil and water conservation practices and two controls was in the following order:ER>VR>BL>FR>CT>SS>FP.ER exhibited a higher soil quality value on a slope scale.In the low mountain and hilly region of Northeast China,ER is a better choice than the conversion of farmlands to planted grasslands and woodlands early in the soil and water conservation program.
基金Acknowledgement: The authors appreciate the support of the West Transportation Construction Science and Technology of China (No. 200331879805) and Hunan Provincial Natural Science Foundation of China (No. 07JJ3111).
文摘The highway construction inevitably may cause certain influence to the cultural heritage and the natural environment along the route, particularly in design stage; if the route selection is unreasonable, it will certainly impact the natural resource seriously along the route. On the contrary, good design can reasonably develop, use, protect and promote the value of cultural heritage and natural environment. Changsha to Jishou (Chang-Ji) freeway is one section of Changsha to Chongqing freeway, which is one of the eight big west channels as planned in China; two cities of Changde and Huaihua and one autonomous region of Xianxi in western Hunan province, along which the cultural heritage and the natural resource are rich, and the natural landscape is exquisite. This paper investigates and analyzes the natural resources along the route of Chang-Ji freeway, puts forward some protection design evaluation indexes for mountain area freeway by the thought of context sensitive design. At last, the paper introduces the effect of applying the indexes to select route of Chang-Ji freeway.
基金Supported by the National Natural Science Foundation of China(Nos.40676026,41076079,40831160519)the Basic Research Program of China(973Program)(No.2010CB428704)
文摘We studied diatom distribution from 62 samples from the uppermost 1 cm of sedimem in the South China Sea (SCS), using grabs or box corers in three cruises between 2001-2007. Fifty six genera, 256 species and their varieties were identified. Dominating species included Coscinodiscus africanus, Coscinodiscus nodulifer, Cyclotella stylorum, Hemidiscus cuneiformis, Melosira sulcata, Nitzschia marina, Roperia tesselata, Thalassionema nitzschioides, Thalassiosira excentrica, and Thalassiothrix longissima. Most surface sediments in the SCS were rich ill diatoms, except for a few coarse samples. Average diatom abundance in the study area was 104 607 valve/g. In terms of the abundance, ecology, and spatial distribution, seven diatom zones (Zones 1-7) were recognized. Zone 1 (northern continental shelf) is affected by warm currents, SCS northern branch of the Kuroshio, and northern coastal currents; Zone 2 (northwestern continental shelf) is affected by intense coastal currents; Zone 3 (Xisha Islands sea area) is a bathyal environment with transitional water masses; Zone 4 (sea basin) is a bathyal-to-deep sea with stable and uniform central water masses in a semi-enclosed marginal sea; Zone 5 (Nansba Islands marine area) is a pelagic environment with relatively high surface temperature; Zone 6 (northern Sunda Shelf) is a tropical shelf environment; and Zone 7 (northern Kalimantan Island shelf area) is affected by warm waters from the Indian Ocean and coastal waters. The data indicate that these diatom zones are closely related to topography, hydrodynamics, temperature, nutrients and especially the salinity. Better understanding of the relationship between diatom distribution and the oceanographic factors would help in the reconstruction of the SCS in the past.
文摘Venous complications in patients with acute pancreatitis typically occur as a form of splenic,portal,or superior mesenteric vein thrombosis and have been detected more frequently in recent reports.Although a well-organized protocol for the treatment of venous thrombosis has not been established,anticoagulation therapy is commonly recommended.A 73-year-old man was diagnosed with acute progressive portal vein thrombosis associated with acute pancreatitis.After one month of anticoagulation therapy,the patient developed severe hematemesis.With endoscopy and an abdominal computed tomography scan,hemorrhages in the pancreatic pseudocyst,which was ruptured into the duodenal bulb,were confirmed.After conservative treatment,the patient was stabilized.While the rupture of a pseudocyst into the surrounding viscera is a well-known phenomenon,spontaneous rupture into the duodenum is rare.Moreover,no reports of upper gastrointestinal bleeding caused by pseudocyst rupture in patients under anticoagulation therapy for venous thrombosis associated with acute pancreatitis have been published.Herein,we report a unique case of massive upper gastrointestinal bleeding due to pancreatic pseudocyst rupture into the duodenum,which developed during anticoagulation therapy for portal vein thrombosis associated with acute pancreatitis.
文摘AIM:To evaluate the impact of surgical volume on nationwide hospital mortality after pancreaticoduodenectomy(PD) for periampullary tumors in South Korea.METHODS:Periampullary cancer patients who underwent PD between 2005 and 2008 were analyzed from the database of the Health Insurance Review and Assessment Service of South Korea.A total of 126 hospitals were divided into 5 categories,each similar in terms of surgical volume for each category.We used hospital mortality as a quality indicator,which was defined as death during the hospital stay for PD,and calculated adjusted mortality through multivariate logistic models using several confounder variables.RESULTS:A total of eligible 4975 patients were enrolled in this study.Average annual surgical volume of hospitals was markedly varied,ranging from 215 PDs in the very-high-volume hospital to < 10 PDs in the verylow-volume hospitals.Admission route,type of medical security,and type of operation were significantly different by surgical volume.The overall hospital mortality was 2.1% and the observed hospital mortality by surgical volume showed statistical difference.Surgical volume,age,and type of operation were independent risk factors for hospital death,and adjusted hospital mortality showed a similar difference between hospitals with observed mortality.The result of the HosmerLemeshow test was 5.76(P = 0.674),indicating an acceptable appropriateness of our regression model.CONCLUSION:The higher-volume hospitals showed lower hospital mortality than the lower-volume hospitals after PD in South Korea,which were clarified through the nationwide database.
文摘As the protected areas of land and coastal environment, nature reserves are designed to address how to reconcile the conservation of biodiversity, the quest for economic and social development and the maintenance of cultural values. This paper establishes a framework for nature reserve development that seeks to incorporate ecotourism into its strategies. The overall purpose was to identify the information needs required for a comprehensive nature reserve that incorporates ecotourism related values. It also illustrates the utility of this framework in the context of the Wuzhishan Mountain Region of China. A literature review, the first phase of a visionary strategy and a subsequent gap analysis for available management information were undertaken in order to achieve this paper's purpose. Finally, recommendations axe pre-sented for integrating ecotourism into nature reserve development in the Wuzhishan Mountain Region.