AIM： To study the effects of endogeous nitric oxide induced by 5-fluorouracil （5-FU） and L-arginine （L-Arg） on the human liver carcinoma model in nude mice. METHODS： The human liver carcinoma model in nude mice ...AIM： To study the effects of endogeous nitric oxide induced by 5-fluorouracil （5-FU） and L-arginine （L-Arg） on the human liver carcinoma model in nude mice. METHODS： The human liver carcinoma model in nude mice was established with BEL-7402 cells and normal saline （NS）, 5-FU and 5-FU ＋ L-Arg injected intraperitoneally. The tumor size was measured. The necrotic degree and range were observed under microscope. The apoptosis of cancer cell was detected by turmina deoxynucleotidyl transferanse mediated dUTP nick end labeling （TUNEL） method. Immunohistochemical method was performed to determine the expression of iNOS, P16, BAX. The chemical colorimetry was used to test the activity and nitrate reductase method was adopted to test the concentration of nitric oxide （NO） in the tumor tissue. The BI2000 pathological image analyzer was used to analyze the result of immunohistochemistry. RESULTS： 5-FU combined with L-Arg could inhibit the tumor growth apparently. In NS, 5-FU and 5-FU＋L- Arg groups, the changes of tumor volumes were 257.978 ± 59.0, 172.232 ± 66.0 and 91.523 ± 26.7 mm3, respectively （P 〈 0.05 5-FU vs 5-FU ± L-Arg group;P 〈 0.05 NS ys 5-FU ± L-Arg group; P 〈 0.05, NS ys 5-FU group）. The necrotic range and apoptosis index were significantly increased after the drug injection. The necrotic range was biggest in 5-FU ＋ L-Arg group （X^2= 15.963, P 〈 0.05）. The apoptosis indexes were as follows： NS, 17.4% ± 6.19%; 5-FU, 31.3% ± 12.3%; and 5-FU ± L-Arg, 46% ± 15.24% （P 〈 0.05, 5-FU ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU）. The expression and activity of iNOS were increased in the tumor tissue. The concentration of NO was also increased. F of opticaldensity of iNOS, iNOS activity and NO concentration are 31.693, 21.949, and 33.909, respectively, P 〈 0.05. The concentration of NO was related to the expression of PI6 and BAX. The correlation coefficient was 0.764 and 0.554. CONCLUSION： 5-FU combined with L-Arg can inhibit the growth of tumor in nude mice. The effect may be related to inducing the synthesis and increasing the activity of iNOS. The production of NO is increased, and it can enhance the expression of apoptosis-related gene and antioncogene.展开更多
BACKGROUND Osteoporosis is a global disease affecting 6.6%of the total population.Osteoporosis complications include fractures,increased bone fragility,and reduced bone strength.The most commonly affected parts are th...BACKGROUND Osteoporosis is a global disease affecting 6.6%of the total population.Osteoporosis complications include fractures,increased bone fragility,and reduced bone strength.The most commonly affected parts are the vertebral body,hip,and wrist.AIM To examine the effect of alendronate sodium combined with InterTan for osteoporotic femoral intertrochanteric fractures on bone and fracture recurrence METHODS In total,126 cases of osteoporotic femoral intertrochanteric fractures were selected and divided into two groups according to the 1:1 principle by the simple random method.They were admitted to the Department of Orthopedics,First Affiliated Hospital of Xingtai Medical College,from January 2018 to September 2020.The control group was treated with InterTan fixation combined with placebo,and the observation group with alendronate sodium based on InterTan fixation.Operation-related indicators,complications,and recurrent fractures were compared between the groups.Changes in bone metabolism markers,t value for hip bone mineral density,and Harris Hip Score were observed.RESULTS Operation time,intraoperative blood loss,postoperative ambulation time,and complications were compared between the groups,and no significant difference was found.The fracture healing time was significantly shorter in the observation group than in the control group.β-Collagen-specific sequence(β-CTX)and total aminoterminal propeptide of type I procollagen(T-PINP)in the control group at 3 mo after operation were compared with those before operation,and the difference was not significant.Six months after the operation,theβ-CTX level decreased and T-PINP level increased.β-CTX level at 3 and 6 mo in the observation group after operation was lower,and TPINP level was higher,than that before operation.Compared with the control group,T-PINP level of the observation group was significantly higher andβ-CTX level was significantly lower at 3 and 6 mo after operation.The t value of hip bone mineral density was compared in the control group before and 1 mo after operation,and significant difference was not found.Compared with the control group,the t value of hip bone mineral density in the observation group was significantly higher at 1,3,6,and 12 mo after operation.Compared with the control group,the Harris score of the observation group was significantly higher at 1,3,6,and 12 mo after operation.The recurrence rate of fractures in the observation group within 12 mo was 0.00%,which was significantly lower than 6.35%in the control group.CONCLUSION Alendronate sodium combined with InterTan in the treatment of osteoporotic femoral intertrochanteric fractures can increase bone mineral density,improve hip joint function,promote fracture healing,and reduce fracture recurrence.展开更多
BACKGROUND Gastric adenocarcinoma of fundic gland type (GA-FG) has recently been proposed as a novel histological type of gastric cancer. CASE SUMMARY We report a case of GA-FG in a 77-year-old Chinese woman with epig...BACKGROUND Gastric adenocarcinoma of fundic gland type (GA-FG) has recently been proposed as a novel histological type of gastric cancer. CASE SUMMARY We report a case of GA-FG in a 77-year-old Chinese woman with epigastric distention who was referred to endoscopy for the management of an incidentally found submucosal tumor-like elevated lesion in the lower part of the gastric body. The tumor occurred after Helicobacter pylori (H. pylori) eradication therapy without long-term use of proton pump inhibitors. Complete and curable removal of the tumor was performed by endoscopic submucosal dissection. Histopathological findings showed numerous cells with basophilic cytoplasm and mildly atypical nuclei-like chief cells of the fundic gland. The tumor was observed to have the so-called “endless glands” pattern of the well-differentiated mixed phenotype. A safe resection margin without lymphatic and venous invasion was observed. As the tumor occurred after H. pylori eradication therapy, it is unknown whether there was a relationship with H. pylori eradication. The patient will be followed up by periodic gastroscopic observation. CONCLUSION In conclusion, we report a case of GA-FG after H. pylori eradication therapy without long-term proton pump inhibitors use. Further analysis of similar cases will reveal the clinical behavior of GA-FG.展开更多
BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearance...BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearances.There is no uniform consensus on its treatment.With the advancement of endoscopic technology,endoscopic treatment has achieved better results in individual case reports of early-stage patients.CASE SUMMARY We report a case of rectal MALT in a 57-year-old Chinese man with no symptoms who received endoscopy as part of a routine physical examination,which incidentally found a 25 mm×20 mm,laterally spreading tumor(LST)-like elevated lesion in the rectum.Therefore,he was referred to our hospital for further endoscopic treatment.Complete and curable removal of the tumor was performed by endoscopic submucosal dissection.We observed enlarged and dilated branch-like vessels similar to those of gastric MALT lymphoma on magnifying endoscopy with narrow-band imaging.And immunopathological staining showed hyperplastic capillaries in the mucosa.Histopathological findings revealed diffusely hyperplastic lymphoid tissue in the lamina propria,with a visible lymphoid follicle structure surrounded by a large number of diffusely infiltrated lymphoid cells that had a relatively simple morphology and clear cytoplasm.In addition,immunohistochemical analysis suggested strongly positive expression for CD20 and Bcl-2.Gene rearrangement results showed positivity for IGH-A,IGH-C,IGK-B,and IGL.Taking all the above findings together,we arrived at a diagnosis of extranodal marginal zone B-cell lymphoma of MALT lymphoma. Positron emission tomography-computed tomographyexamination showed no other lesions involved. The patient will be followed byperiodic endoscopic observation.CONCLUSIONIn conclusion, we report a case of rectal MALT with an LST-like appearancetreated by endoscopic submucosal dissection. Further studies will be needed toexplore the clinical behavior, endoscopic appearance, and treatment of rectalMALT.展开更多
BACKGROUND Lymphangiomatosis is a multisystem disorder that is rarely localized to the gastrointestinal tract.Lymphangiomatosis usually has no specific clinical presentation and is easily misdiagnosed.A case report an...BACKGROUND Lymphangiomatosis is a multisystem disorder that is rarely localized to the gastrointestinal tract.Lymphangiomatosis usually has no specific clinical presentation and is easily misdiagnosed.A case report and review of the literature on lymphangiomatosis associated with protein-losing enteropathy will help to improve the overall understanding of this disease.CASE SUMMARY We report a case of lymphangiomatosis of the bowel and other solid organs.A 78-year-old man presented with recurrent bowel bleeding and protein-losing enteropathy,as well as cystic lesions in the spleen,liver,and kidney.Imaging examinations revealed many cystic lesions on the spleen,liver,kidney,and thickened wall of the ascending colon,as well as pleural effusion and ascites.Colonoscopy revealed a strawberry mucosa,variable spontaneous bleeding,and surface erosion located in the terminal ileum.Several cystic masses with a translucent and smooth surface as well as diffuse white spots were located in the colon.A laterally spreading tumor(LST)was located in the ascending colon.Pathology indicated highly differentiated adenocarcinoma(LST)and lymphangiomatoid dilation,and D2-40 was positive.The final diagnosis was lymphangiomatosis.The patient underwent surgery for LST and then was administered thalidomide 75-150 mg/d.His condition,however,did not improve.He eventually died 6 mo after the initial diagnosis.CONCLUSION Lymphangiomatosis usually occurs diffusely and can involve many organs,such as the spleen,kidney,liver,lung,mesentery,and bowel.Recurrent bowel bleeding or protein-losing enteropathy is an important indicator that should alert clinicians about the possibility of this disease when it afflicts the bowel.Doctors should improve the medical understanding of lymphangiomatosis.展开更多
BACKGROUND Enteropathy-associated T-cell lymphoma(EATL)is a rare invasive lymphoma derived from gastrointestinal epithelial T lymphocytes.EATL involving the whole gastrointestinal tract accompanied with early colon ca...BACKGROUND Enteropathy-associated T-cell lymphoma(EATL)is a rare invasive lymphoma derived from gastrointestinal epithelial T lymphocytes.EATL involving the whole gastrointestinal tract accompanied with early colon cancer is extremely rare.CASE SUMMARY We present the case of a 67-year-old man with diarrhea for more than 5 mo whose colonoscopy in another hospital showed multiple colonic polyps,which indicated moderate to severe dysplasia and focal early cancer.Therefore,he was referred to our hospital for further endoscopic treatment.Colonoscopy after admission showed that the mucosa of the terminal ileum and the entire colon were slightly swollen and finely granular.Endoscopic mucosal resection was performed for colonic polyps located in the liver flexure of the colon and descending colon,respectively.Histopathological findings revealed diffuse infiltration of mediumsized lymphoid cells in the colonic mucosa and visible lymphoepithelial lesions.The histopathology of the polyp in the descending colon indicated moderately differentiated adenocarcinoma limited to the mucosa with negative resection margins.Additionally,immunohistochemical analysis showed positive staining for CD7 and CD8.Therefore,we arrived at a diagnosis of EATL with early colon cancer.Subsequently,the patient was transferred to the hematology department for chemotherapy.The patient’s diarrhea was not significantly relieved after receiving chemotherapy,and he ultimately died of severe myelosuppression.CONCLUSION EATL should be considered in unexplained chronic diarrhea.EATL progresses rapidly with a poor prognosis,especially when accompanied with early colon cancer.展开更多
In the two-tier macro-femto heterogeneous network, hybrid access is regarded as the most ideal access con- trol approach to mitigating macro-femto cross-tier interference and enhancing overall network performance. How...In the two-tier macro-femto heterogeneous network, hybrid access is regarded as the most ideal access con- trol approach to mitigating macro-femto cross-tier interference and enhancing overall network performance. However, the implementation of hybrid access is hindered by a lack of incentive market mechanism to motivate private femtocell owners to offer access permissions to macro users. In this paper, we propose a reverse auction framework for access permission transaction between a macrocell operator and multiple femtocell owners to promote hybrid access. Our goal is to maximize social welfare while guaranteeing the truthfulness of the auction. Since the coverage of multiple femtocells may overlap, we partition each cell to adjust the granularity of access permission availability. We first propose a Vickery-Clarke-Grove （VCG）-based mechanism, which costs the least among all auction mechanisms that produce maximum social welfare. As the VCG mechanism is too time-consuming, we propose two alternative truthful mechanisms, namely, generalized second- price and suboptimal mechanism. We further extend the auction framework to the scenario where femtocell owners have heterogeneous valuations for access permissions in different locations.展开更多
基金the Grants for the Excellent Youth Scientists of Shandong Provincial Science Commission.No.2000BB2DBA1
文摘AIM： To study the effects of endogeous nitric oxide induced by 5-fluorouracil （5-FU） and L-arginine （L-Arg） on the human liver carcinoma model in nude mice. METHODS： The human liver carcinoma model in nude mice was established with BEL-7402 cells and normal saline （NS）, 5-FU and 5-FU ＋ L-Arg injected intraperitoneally. The tumor size was measured. The necrotic degree and range were observed under microscope. The apoptosis of cancer cell was detected by turmina deoxynucleotidyl transferanse mediated dUTP nick end labeling （TUNEL） method. Immunohistochemical method was performed to determine the expression of iNOS, P16, BAX. The chemical colorimetry was used to test the activity and nitrate reductase method was adopted to test the concentration of nitric oxide （NO） in the tumor tissue. The BI2000 pathological image analyzer was used to analyze the result of immunohistochemistry. RESULTS： 5-FU combined with L-Arg could inhibit the tumor growth apparently. In NS, 5-FU and 5-FU＋L- Arg groups, the changes of tumor volumes were 257.978 ± 59.0, 172.232 ± 66.0 and 91.523 ± 26.7 mm3, respectively （P 〈 0.05 5-FU vs 5-FU ± L-Arg group;P 〈 0.05 NS ys 5-FU ± L-Arg group; P 〈 0.05, NS ys 5-FU group）. The necrotic range and apoptosis index were significantly increased after the drug injection. The necrotic range was biggest in 5-FU ＋ L-Arg group （X^2= 15.963, P 〈 0.05）. The apoptosis indexes were as follows： NS, 17.4% ± 6.19%; 5-FU, 31.3% ± 12.3%; and 5-FU ± L-Arg, 46% ± 15.24% （P 〈 0.05, 5-FU ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU）. The expression and activity of iNOS were increased in the tumor tissue. The concentration of NO was also increased. F of opticaldensity of iNOS, iNOS activity and NO concentration are 31.693, 21.949, and 33.909, respectively, P 〈 0.05. The concentration of NO was related to the expression of PI6 and BAX. The correlation coefficient was 0.764 and 0.554. CONCLUSION： 5-FU combined with L-Arg can inhibit the growth of tumor in nude mice. The effect may be related to inducing the synthesis and increasing the activity of iNOS. The production of NO is increased, and it can enhance the expression of apoptosis-related gene and antioncogene.
基金Supported by Special Projects for Social Development Areas.
文摘BACKGROUND Osteoporosis is a global disease affecting 6.6%of the total population.Osteoporosis complications include fractures,increased bone fragility,and reduced bone strength.The most commonly affected parts are the vertebral body,hip,and wrist.AIM To examine the effect of alendronate sodium combined with InterTan for osteoporotic femoral intertrochanteric fractures on bone and fracture recurrence METHODS In total,126 cases of osteoporotic femoral intertrochanteric fractures were selected and divided into two groups according to the 1:1 principle by the simple random method.They were admitted to the Department of Orthopedics,First Affiliated Hospital of Xingtai Medical College,from January 2018 to September 2020.The control group was treated with InterTan fixation combined with placebo,and the observation group with alendronate sodium based on InterTan fixation.Operation-related indicators,complications,and recurrent fractures were compared between the groups.Changes in bone metabolism markers,t value for hip bone mineral density,and Harris Hip Score were observed.RESULTS Operation time,intraoperative blood loss,postoperative ambulation time,and complications were compared between the groups,and no significant difference was found.The fracture healing time was significantly shorter in the observation group than in the control group.β-Collagen-specific sequence(β-CTX)and total aminoterminal propeptide of type I procollagen(T-PINP)in the control group at 3 mo after operation were compared with those before operation,and the difference was not significant.Six months after the operation,theβ-CTX level decreased and T-PINP level increased.β-CTX level at 3 and 6 mo in the observation group after operation was lower,and TPINP level was higher,than that before operation.Compared with the control group,T-PINP level of the observation group was significantly higher andβ-CTX level was significantly lower at 3 and 6 mo after operation.The t value of hip bone mineral density was compared in the control group before and 1 mo after operation,and significant difference was not found.Compared with the control group,the t value of hip bone mineral density in the observation group was significantly higher at 1,3,6,and 12 mo after operation.Compared with the control group,the Harris score of the observation group was significantly higher at 1,3,6,and 12 mo after operation.The recurrence rate of fractures in the observation group within 12 mo was 0.00%,which was significantly lower than 6.35%in the control group.CONCLUSION Alendronate sodium combined with InterTan in the treatment of osteoporotic femoral intertrochanteric fractures can increase bone mineral density,improve hip joint function,promote fracture healing,and reduce fracture recurrence.
基金Supported by the National Natural Science Foundation of China,No.81502025China Postdoctoral Science Foundation,No.2018M632631
文摘BACKGROUND Gastric adenocarcinoma of fundic gland type (GA-FG) has recently been proposed as a novel histological type of gastric cancer. CASE SUMMARY We report a case of GA-FG in a 77-year-old Chinese woman with epigastric distention who was referred to endoscopy for the management of an incidentally found submucosal tumor-like elevated lesion in the lower part of the gastric body. The tumor occurred after Helicobacter pylori (H. pylori) eradication therapy without long-term use of proton pump inhibitors. Complete and curable removal of the tumor was performed by endoscopic submucosal dissection. Histopathological findings showed numerous cells with basophilic cytoplasm and mildly atypical nuclei-like chief cells of the fundic gland. The tumor was observed to have the so-called “endless glands” pattern of the well-differentiated mixed phenotype. A safe resection margin without lymphatic and venous invasion was observed. As the tumor occurred after H. pylori eradication therapy, it is unknown whether there was a relationship with H. pylori eradication. The patient will be followed up by periodic gastroscopic observation. CONCLUSION In conclusion, we report a case of GA-FG after H. pylori eradication therapy without long-term proton pump inhibitors use. Further analysis of similar cases will reveal the clinical behavior of GA-FG.
文摘BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearances.There is no uniform consensus on its treatment.With the advancement of endoscopic technology,endoscopic treatment has achieved better results in individual case reports of early-stage patients.CASE SUMMARY We report a case of rectal MALT in a 57-year-old Chinese man with no symptoms who received endoscopy as part of a routine physical examination,which incidentally found a 25 mm×20 mm,laterally spreading tumor(LST)-like elevated lesion in the rectum.Therefore,he was referred to our hospital for further endoscopic treatment.Complete and curable removal of the tumor was performed by endoscopic submucosal dissection.We observed enlarged and dilated branch-like vessels similar to those of gastric MALT lymphoma on magnifying endoscopy with narrow-band imaging.And immunopathological staining showed hyperplastic capillaries in the mucosa.Histopathological findings revealed diffusely hyperplastic lymphoid tissue in the lamina propria,with a visible lymphoid follicle structure surrounded by a large number of diffusely infiltrated lymphoid cells that had a relatively simple morphology and clear cytoplasm.In addition,immunohistochemical analysis suggested strongly positive expression for CD20 and Bcl-2.Gene rearrangement results showed positivity for IGH-A,IGH-C,IGK-B,and IGL.Taking all the above findings together,we arrived at a diagnosis of extranodal marginal zone B-cell lymphoma of MALT lymphoma. Positron emission tomography-computed tomographyexamination showed no other lesions involved. The patient will be followed byperiodic endoscopic observation.CONCLUSIONIn conclusion, we report a case of rectal MALT with an LST-like appearancetreated by endoscopic submucosal dissection. Further studies will be needed toexplore the clinical behavior, endoscopic appearance, and treatment of rectalMALT.
基金The National Natural Science Foundation of China,No.81502025China Postdoctoral Science Foundation,No.2018M632631.
文摘BACKGROUND Lymphangiomatosis is a multisystem disorder that is rarely localized to the gastrointestinal tract.Lymphangiomatosis usually has no specific clinical presentation and is easily misdiagnosed.A case report and review of the literature on lymphangiomatosis associated with protein-losing enteropathy will help to improve the overall understanding of this disease.CASE SUMMARY We report a case of lymphangiomatosis of the bowel and other solid organs.A 78-year-old man presented with recurrent bowel bleeding and protein-losing enteropathy,as well as cystic lesions in the spleen,liver,and kidney.Imaging examinations revealed many cystic lesions on the spleen,liver,kidney,and thickened wall of the ascending colon,as well as pleural effusion and ascites.Colonoscopy revealed a strawberry mucosa,variable spontaneous bleeding,and surface erosion located in the terminal ileum.Several cystic masses with a translucent and smooth surface as well as diffuse white spots were located in the colon.A laterally spreading tumor(LST)was located in the ascending colon.Pathology indicated highly differentiated adenocarcinoma(LST)and lymphangiomatoid dilation,and D2-40 was positive.The final diagnosis was lymphangiomatosis.The patient underwent surgery for LST and then was administered thalidomide 75-150 mg/d.His condition,however,did not improve.He eventually died 6 mo after the initial diagnosis.CONCLUSION Lymphangiomatosis usually occurs diffusely and can involve many organs,such as the spleen,kidney,liver,lung,mesentery,and bowel.Recurrent bowel bleeding or protein-losing enteropathy is an important indicator that should alert clinicians about the possibility of this disease when it afflicts the bowel.Doctors should improve the medical understanding of lymphangiomatosis.
基金Supported by National Natural Science Foundation of China,No.81802777Shandong Higher Education Research Center Scientific Research Project,No.YJKT201953+2 种基金Shandong Province 2018 Professional Degree Postgraduate Teaching Case Library Project,No.SDYAL18049Shandong Province 2018 Postgraduate Mentoring Ability Improvement Project,No.SDYY18073and the"Clinical Medicine+X"Project of Qingdao University Hospital.
文摘BACKGROUND Enteropathy-associated T-cell lymphoma(EATL)is a rare invasive lymphoma derived from gastrointestinal epithelial T lymphocytes.EATL involving the whole gastrointestinal tract accompanied with early colon cancer is extremely rare.CASE SUMMARY We present the case of a 67-year-old man with diarrhea for more than 5 mo whose colonoscopy in another hospital showed multiple colonic polyps,which indicated moderate to severe dysplasia and focal early cancer.Therefore,he was referred to our hospital for further endoscopic treatment.Colonoscopy after admission showed that the mucosa of the terminal ileum and the entire colon were slightly swollen and finely granular.Endoscopic mucosal resection was performed for colonic polyps located in the liver flexure of the colon and descending colon,respectively.Histopathological findings revealed diffuse infiltration of mediumsized lymphoid cells in the colonic mucosa and visible lymphoepithelial lesions.The histopathology of the polyp in the descending colon indicated moderately differentiated adenocarcinoma limited to the mucosa with negative resection margins.Additionally,immunohistochemical analysis showed positive staining for CD7 and CD8.Therefore,we arrived at a diagnosis of EATL with early colon cancer.Subsequently,the patient was transferred to the hematology department for chemotherapy.The patient’s diarrhea was not significantly relieved after receiving chemotherapy,and he ultimately died of severe myelosuppression.CONCLUSION EATL should be considered in unexplained chronic diarrhea.EATL progresses rapidly with a poor prognosis,especially when accompanied with early colon cancer.
基金This work was supported in part by the National Natural Science Foundation of China under Grant Nos. 61702380, 61202393, and 61701216, the CPSF （China Postdoctoral Science foundation） under Grant No. 2012M521797, the International Cooperation Foundation of Shaanxi Province of China under Grant No. 2013KW01-02, the International Postdoctoral Exchange Fellowship Program 2013 under Grant No. 57 funded by the Office of China Postdoctoral Council, and Shenzhen Science, Technology and Innovation Commission Basic Research Project under Orant Nos. JCYJ 20160531190935987 and JCYJ 20160531191011045.
文摘In the two-tier macro-femto heterogeneous network, hybrid access is regarded as the most ideal access con- trol approach to mitigating macro-femto cross-tier interference and enhancing overall network performance. However, the implementation of hybrid access is hindered by a lack of incentive market mechanism to motivate private femtocell owners to offer access permissions to macro users. In this paper, we propose a reverse auction framework for access permission transaction between a macrocell operator and multiple femtocell owners to promote hybrid access. Our goal is to maximize social welfare while guaranteeing the truthfulness of the auction. Since the coverage of multiple femtocells may overlap, we partition each cell to adjust the granularity of access permission availability. We first propose a Vickery-Clarke-Grove （VCG）-based mechanism, which costs the least among all auction mechanisms that produce maximum social welfare. As the VCG mechanism is too time-consuming, we propose two alternative truthful mechanisms, namely, generalized second- price and suboptimal mechanism. We further extend the auction framework to the scenario where femtocell owners have heterogeneous valuations for access permissions in different locations.
