Stapes fracture causes hearing loss and instability in the middle ear hearing system(MEHS). The material used in the stapes reconstruction restores stapes, but the effects of the nonlinear material parameters on the s...Stapes fracture causes hearing loss and instability in the middle ear hearing system(MEHS). The material used in the stapes reconstruction restores stapes, but the effects of the nonlinear material parameters on the stability of the MEHS are still unknown. To address this challenge, the nonlinear dynamic response and stability of the stapes reconstruction are investigated using a multi-degree-of-freedom mechanical model. The material parameters of the implant are tentatively determined by analyzing the natural frequencies of the undamped system. The dynamical properties of the MEHS are characterized under different external excitations. The approximate solution of the MEHS near the resonant frequency is derived through the multiple-time-scale method(MTSM). The results show that the nonlinear stiffness of the material has little influence on the MEHS in the healthy state, but it causes resonant phenomena between the ossicle and the implant in the pathological state.展开更多
BACKGROUND Pancreatic neuroendocrine neoplasms(PNENs)are a rare group of neoplasms originating from the islets of the Langerhans.Portal vein tumor thrombosis has been reported in 33%of patients with PNENs.While the hi...BACKGROUND Pancreatic neuroendocrine neoplasms(PNENs)are a rare group of neoplasms originating from the islets of the Langerhans.Portal vein tumor thrombosis has been reported in 33%of patients with PNENs.While the histopathological diagnosis of PNENs is usually based on percutaneous biopsy or endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA),these approaches may be impeded by gastric varices,poor access windows,or anatomically contiguous critical structures.Obtaining a pathological diagnosis using a gastroscope biopsy forceps via percutaneous transhepatic intravascular pathway is an innovative method that has rarely been reported.CASE SUMMARY A 72-year-old man was referred to our hospital for abdominal pain and melena.Abdominal contrast-enhanced magnetic resonance imaging revealed a wellenhanced tumor(size:2.4 cm×1.2 cm×1.2 cm)in the pancreatic tail with portal vein invasion.Traditional pathological diagnosis via EUS-FNA was not possible because of diffuse gastric varices.We performed a percutaneous transportal biopsy of the portal vein tumor thrombus using a gastroscope biopsy forceps.Histopathologic examination revealed a pancreatic neuroendocrine neoplasm(G2)with somatostatin receptors 2(+),allowing systemic treatment.CONCLUSION Intravascular biopsy using gastroscope biopsy forceps appears to be a safe and effective method for obtaining a histopathological diagnosis.Although welldesigned clinic trials are required to obtain more definitive evidence,this procedure may help improve the diagnosis of portal vein thrombosis and related diseases.展开更多
After being ingested and entering the human stomach,Helicobacter pylori(H.pylori)adopts several effective strategies to adhere to and colonize the gastric mucosa and move to different regions of the stomach to obtain ...After being ingested and entering the human stomach,Helicobacter pylori(H.pylori)adopts several effective strategies to adhere to and colonize the gastric mucosa and move to different regions of the stomach to obtain more nutrients and escape from the harsher environments of the stomach,leading to acute infection and chronic gastritis,which is the basis of malignant gastric tumors.The endoscopic manifestations and pathological features of H.pylori infection are diverse and vary with the duration of infection.In this review,we describe the endoscopic manifestations of each stage of H.pylori gastritis and then reveal the potential mechanisms of bacterial intragastric colonization and migration from the perspective of endoscopists to provide direction for future research on the effective therapy and management of H.pylori infection.展开更多
AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon te...AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.展开更多
At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the bil...At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the biliary reconstruction after resection, almost all surgeons use Roux-en-Y hepaticojejunostomy. A viable alternative to Roux-en-Y reconstruction after radical resection of hilar cholangiocarcinoma has not yet been proposed. We report a case of performing duct-to-duct biliary reconstruction after radical resection of Bismuth Ⅲa hilar cholangiocarcinoma. End-to-end anastomosis between the left hepatic duct and the distal common bile duct was used for the biliary reconstruction, and a singlelayer continuous suture was performed along the bile duct using 5-0 prolene. The patient was discharged favorably without biliary fistula 2 wk later. Evidence for tumor recurrence was not found after an 18 mo follow- up. Performing bile duct end-to-end anastomosis in hilar cholangiocarcinoma can simplify the complex digestive tract reconstruction process.展开更多
AIM: To investigate the effect of carvedilol on angiogenesis and the underlying signaling pathways.METHODS: The effect of carvedilol on angiogenesis was examined using a human umbilical vascular endothelial cell(HUVEC...AIM: To investigate the effect of carvedilol on angiogenesis and the underlying signaling pathways.METHODS: The effect of carvedilol on angiogenesis was examined using a human umbilical vascular endothelial cell(HUVEC) model. The effect of carvedilol on cell viability was measured by CCK8 assay. Flow cytometry was used to assess the effect of carvedilol on cell cycle progression. Cell migration, transwell migration and tube formation assays were performed to analyze the effect of carvedilol on HUVEC function. Vascular endothelial growth factor(VEGF) induced activation of HUVECs, which were pretreated with different carvedilol concentrations or none. Western blot analysis detected the phosphorylation levels of three cell signaling pathway proteins, VEGFR-2, Src, and extracellular signal-regulated kinase(ERK). The specific Src inhibitor PP2 was used to assess the role of Src in the VEGF-induced angiogenic pathway.RESULTS: Carvedilol inhibited HUVEC proliferation in a dose-dependent manner(IC50 = 38.5 mmol/L). The distribution of cells in the S phase decreased from 43.6% to 37.2%, 35.6% and 17.8% by 1, 5 and 10 μmol/L carvedilol for 24 h, respectively. Carvedilol(10 μmol/L) reduced VEGF-induced HUVEC migration from 67.54 ± 7.83 to 37.11 ± 3.533(P < 0.001). Carvedilol concentrations of 5 μmol/L and 10 μmol/L reduced cell invasion from 196.3% ± 18.76% to 114.0% ± 12.20% and 51.68% ± 8.28%, respectively. VEGFinduced tube formation was also reduced significantly by 5 μmol/L and 10 μmol/L carvedilol from 286.0 ± 36.72 to 135.7 ± 18.13(P < 0.05) and 80.27 ± 11.16(P < 0.01) respectively. We investigated several intracellular protein levels to determine the reason for these reductions. Treatment with 10 μmol/L carvedilol reduced VEGF-induced tyrosine phosphorylation of VEGFR-2 from 175.5% ± 8.54% to 52.67% ± 5.33%(P < 0.01). Additionally, 10 μmol/L carvedilol reduced VEGF-induced ERK 1/2 phosphorylation from 181.9% ± 18.61% to 56.45% ± 7.64%(P < 0.01). The VEGFinduced increase in Src kinase activity was alleviated by carvedilol [decreased from 141.8% ± 15.37% to 53.57 ± 7.18%(P < 0.01) and 47.04% ± 9.74%(P < 0.01) at concentrations of 5 and 10 μmol/L, respectively]. Pretreatment of HUVECs with Src kinase inhibitor almost completely prevented the VEGF-induced ERK upregulation [decreased from 213.2% ± 27.68% to 90.96% ± 17.16%(P < 0.01)].CONCLUSION: Carvedilol has an anti-angiogenic effect on HUVECs. This inhibitory effect is mediated by VEGF-induced Src-ERK signaling pathways.展开更多
AIM: To assess whole-body fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the management of small bowel obstructions (SBOs) secondary to gastric cancer and its role in treatment s...AIM: To assess whole-body fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the management of small bowel obstructions (SBOs) secondary to gastric cancer and its role in treatment strategies. METHODS: The medical records of all of the patients who were admitted for an intestinal obstruction after curative resection for gastric cancer were retrospectively reviewed. PET/CT was performed before a clinical treatment strategy was established for each patient. The patients were divided into 2 groups: patients with no evidence of a tumor recurrence and patients with evidence of a tumor recurrence. Tumor recurrences included a local recurrence, peritoneal carcinomatosis or distant metastases. The primary endpoint was the 1-year survival rate, and other variables included patient demographics, the length of hospital stay, complications, and mortality. RESULTS: The median time between a diagnosis of gastric cancer and the detection of a SBO was 1.4 years. Overall, 31 of 65 patients (47.7%) had evidence of a tumor recurrence on the PET/CT scan, which was the only factor that was associated with poor survival. Open and close surgery was the main type of surgical procedure reported for the patients with tumor recurrences. R0 resections were performed in 2 patients, including 1 who underwent combined adjacent organ resection. In the group with no evidence of a tumor recurrence on PET/CT, bowel resections were performed in 7 patients, adhesiolysis was performed in 7 patients, and a bypass was performed in 1 patient. The 1-year survival curves according to PET/CT evidence of a tumor recurrence vs no PET/CT evidence of a tumor recurrence were significantly different, and the 1-year survival rates were 8.8% vs 93.5%, respectively. There were no significant differences (P = 0.71) in the 1-year survival rates based on surgical vs nonsurgical management (0% with nonoperative treatment vs 20% after exploratory laparotomy). CONCLUSION: 18 F-FDG PET/CT can be used to identify the causes of bowel obstructions in patients with a history of gastric cancer, and this method is useful for planning the surgical management of these patients.展开更多
Phononic crystals(PCs) have recently been developed as effective components for vibration suppression and sound absorption. As a typical design of PCs, wave attenuation occurs in the so-called stop-band. However, the ...Phononic crystals(PCs) have recently been developed as effective components for vibration suppression and sound absorption. As a typical design of PCs, wave attenuation occurs in the so-called stop-band. However, the structural response is still significantly large in the pass-band. In this paper, we combine PCs and acoustic black holes(ABHs) in a unique device, achieving a versatile device that can attenuate vibration in the stop-band, while suppress vibration in the pass-band. This approach provides a versatile platform for controlling vibration in a multiband with a simple design.展开更多
A multi-objective optimization of non-uniform beams is presented for minimum radiated sound power and weight. The transfer matrix method is used to compute the structural and acoustic responses of a non-uniform beam a...A multi-objective optimization of non-uniform beams is presented for minimum radiated sound power and weight. The transfer matrix method is used to compute the structural and acoustic responses of a non-uniform beam accurately and efficiently. The multi-objective particle swarm optimization technique is applied to search the Pareto optimal solutions that represent various compromises between weight and sound radiation. Several constraints are imposed, which substantially reduce the volume fraction of feasible solutions in the design space. Two nonuniform beams with different boundary conditions are studied to demonstrate the multi-objective optimal designs of the structure.展开更多
In this paper, we investigate a multi-objective optimal design of a tuned vibration absorber for a two degrees-of-freedom linear system, in which we take white Gaussian noise as the excitation. We use the simple cell ...In this paper, we investigate a multi-objective optimal design of a tuned vibration absorber for a two degrees-of-freedom linear system, in which we take white Gaussian noise as the excitation. We use the simple cell mapping method to obtain solutions to the multi-objective optimization problem. We optimize tuned vibration absorbers in two different configurations. As our objective,we take various features of the response of the power spectrum density function. Our results show that the primary mass vibration with the optimally designed absorber has a lower peak power spectrum value. In addition, the two natural frequencies of the optimized system are further apart than in the non-optimized system, which implies that the absorber has a wider effective region in the frequency domain.展开更多
The nonlinear resonance response of an electrostatically actuated nanobeam is studied over the near-half natural frequency with an axial capacitor controller. A graphene sensor deformed by the vibrations of the nanobe...The nonlinear resonance response of an electrostatically actuated nanobeam is studied over the near-half natural frequency with an axial capacitor controller. A graphene sensor deformed by the vibrations of the nanobeam is used to produce the voltage signal. The voltage of the vibration graphene sensor is used as a control signal input to a closed- loop circuit to mitigate the nonlinear vibration of the nanobeam. An axial control force produced by the axial capacitor controller can transform the frequency-amplitude curves from nonlinear to linear. The necessary and sufficient conditions for guaranteeing the system stability and a saddle-node bifurcation are studied. The numerical simulations are conducted for uniform nanobeams. The nonlinear terms of the vibration system can be transformed into linear ones by applying the critical control voltage to the system. The nonlinear vibration phenomena can be avoided, and the vibration amplitude is mitigated evidently with the axial capacitor controller.展开更多
Objective:To study the effect of inhibiting high mobility group box 1(HMGB1)gene expression on ultrasonic blood flow characteristics,inflammatory response and apoptosis in diabetic retinopathy rats.Methods:Male SD rat...Objective:To study the effect of inhibiting high mobility group box 1(HMGB1)gene expression on ultrasonic blood flow characteristics,inflammatory response and apoptosis in diabetic retinopathy rats.Methods:Male SD rats were chosen and randomly divided into control group,model group and HMGB1 inhibition group,the latter two groups were given intraperitoneal injection of streptozotocin to establish the diabetes model,and HMGB1 group were given tail vein injection of HMGB1-shRNA lentivirus for intervention.The peak end-systolic velocity(PSV),peak end-diastolic velocity(EDV),resistance index(RI)and pulsatility index(PI)of central retinal artery as well as the HMGB1,bcl-2,bax and cleaved caspase-3 expression and TNF-α,MCP-1 and ICAM-1 contents in retinal tissues were measured at 4 weeks after intervention.Results:The PSV and EDV levels as well as bcl-2 expression in the model group were lower than those in the control group,while the RI and PI levels as well as HMGB1,bax and cleaved caspase-3 expression and TNF-α,MCP-1 and ICAM-1 contents were higher than those in the control group;the PSV and EDV levels as well as bcl-2 expression in the HMGB1 inhibition group were higher than those in the model group,while the RI and PI levels as well as HMGB1,bax and cleaved caspase-3 expression and TNF-α,MCP-1 and ICAM-1 contents were lower than those in the model group.Conclusion:Inhibition of HMGB1 gene expression can improve the blood flow of central retinal artery and inhibit the inflammatory response and apoptosis in diabetic retinopathy rats.展开更多
Objective To evaluate the long-term outcome and prognostic factors of patients with nasopharyngeal carcinoma(NPC)from low-endemic regions of China who received definitive intensity-modulated radiation therapy(IMRT).Me...Objective To evaluate the long-term outcome and prognostic factors of patients with nasopharyngeal carcinoma(NPC)from low-endemic regions of China who received definitive intensity-modulated radiation therapy(IMRT).Methods The clinical data from 608 patients with newly-diagnosed non-metastatic NPC who have received initial treatment at our cancer center from January,2008 to December,2013 were retrospectively reviewed.All patients received definitive IMRT,and 87.7%received platinum-based chemotherapy.Results The median follow-up duration was 51 months(follow-up rate,98.5%;range,10–106 months)for the entire cohort.The 5-year overall survival rate was 79.7%.The 5-year local relapse-free survival rate,regional relapse-free survival rate,distant metastasis-free survival rate and progression-free survival rate were 92.4%,93.3%,79.2%and 74.3%,respectively.A total of 153 patients had experienced treatment failure,with distant metastasis as the primary cause in 77.1%(118/153).Patients with T4 or N3 diseases had a significantly poorer prognosis than other subcategories.Stage T4 and N3 were closely associated with distant metastasis,with the metastatic rate of 29.3%and 45.5%,respectively.Conclusion IMRT provides patients with non-metastatic NPC with satisfactory long-term survival.Both T stage and N stage are important prognostic factors for NPC patients.Patients with T4 or N3 diseases have significantly increased distant metastatic rates and poor survival time.展开更多
The data-driven methods extract the feature information from data to build system models, which enable estimation and identification of the systems and can be utilized for prognosis and health management(PHM). However...The data-driven methods extract the feature information from data to build system models, which enable estimation and identification of the systems and can be utilized for prognosis and health management(PHM). However, most data-driven models are still black-box models that cannot be interpreted. In this study, we use the neural ordinary differential equations(ODEs), especially the inherent computational relationships of a system added to the loss function calculation, to approximate the governing equations. In addition, a new strategy for identifying the local parameters of the system is investigated, which can be utilized for system parameter identification and damage detection. The numerical and experimental examples presented in the paper demonstrate that the strategy has high accuracy and good local parameter identification. Moreover, the proposed method has the advantage of being interpretable. It can directly approximate the underlying governing dynamics and be a worthwhile strategy for system identification and PHM.展开更多
BACKGROUND Oral lichen planus(OLP)is a chronic inflammatory disorder,and it can affect normal oral function.The conventional treatments for OLP are not always effective,and relapse easily occurs.Therefore,treatment of...BACKGROUND Oral lichen planus(OLP)is a chronic inflammatory disorder,and it can affect normal oral function.The conventional treatments for OLP are not always effective,and relapse easily occurs.Therefore,treatment of OLP is difficult and challenging.In this study,we evaluated over a long period the clinical efficacy of surgical excision and acellular dermal matrix(ADM)grafting in patients with refractory OLP.CASE SUMMARY Eleven patients with refractory OLP underwent a standardized protocol of surgical excision and ADM grafting.The condition of the area of the grafted wound,the intraoperative maximum mouth opening,pain,and clinical healing were assessed at postoperative follow-up visits.All patients had a flat surgical area with similar mucosal tissue coverage and local scar formation.Patients had no irritation and pain in their mucous membranes when eating acidic and spicy food.All patients’mouth openings returned to normal within 2-6 mo after surgery.During follow-up,none of the patients had recurrence of OLP after surgery.The longest follow-up was 11 yr and the shortest was 6 mo,and none of the patients relapsed during follow-up.CONCLUSION Surgical excision and ADM grafting could be an effective method to treat refractory OLP.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 12072222, 12132010,12021002, 11991032, and 12372019)the State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures of China (No. SKLTESKF1901)the Aeronautical Science Foundation of China (No. ASFC-201915048001)。
文摘Stapes fracture causes hearing loss and instability in the middle ear hearing system(MEHS). The material used in the stapes reconstruction restores stapes, but the effects of the nonlinear material parameters on the stability of the MEHS are still unknown. To address this challenge, the nonlinear dynamic response and stability of the stapes reconstruction are investigated using a multi-degree-of-freedom mechanical model. The material parameters of the implant are tentatively determined by analyzing the natural frequencies of the undamped system. The dynamical properties of the MEHS are characterized under different external excitations. The approximate solution of the MEHS near the resonant frequency is derived through the multiple-time-scale method(MTSM). The results show that the nonlinear stiffness of the material has little influence on the MEHS in the healthy state, but it causes resonant phenomena between the ossicle and the implant in the pathological state.
基金the National Natural Science Foundation of China,No.82000566Natural Science Foundation of Shandong Province,No.ZR2020QH036 and No.ZR2022MH010.
文摘BACKGROUND Pancreatic neuroendocrine neoplasms(PNENs)are a rare group of neoplasms originating from the islets of the Langerhans.Portal vein tumor thrombosis has been reported in 33%of patients with PNENs.While the histopathological diagnosis of PNENs is usually based on percutaneous biopsy or endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA),these approaches may be impeded by gastric varices,poor access windows,or anatomically contiguous critical structures.Obtaining a pathological diagnosis using a gastroscope biopsy forceps via percutaneous transhepatic intravascular pathway is an innovative method that has rarely been reported.CASE SUMMARY A 72-year-old man was referred to our hospital for abdominal pain and melena.Abdominal contrast-enhanced magnetic resonance imaging revealed a wellenhanced tumor(size:2.4 cm×1.2 cm×1.2 cm)in the pancreatic tail with portal vein invasion.Traditional pathological diagnosis via EUS-FNA was not possible because of diffuse gastric varices.We performed a percutaneous transportal biopsy of the portal vein tumor thrombus using a gastroscope biopsy forceps.Histopathologic examination revealed a pancreatic neuroendocrine neoplasm(G2)with somatostatin receptors 2(+),allowing systemic treatment.CONCLUSION Intravascular biopsy using gastroscope biopsy forceps appears to be a safe and effective method for obtaining a histopathological diagnosis.Although welldesigned clinic trials are required to obtain more definitive evidence,this procedure may help improve the diagnosis of portal vein thrombosis and related diseases.
基金Medical Health Science and Technology Development Plan Project of Shandong Province,No.202103030765Natural Science Foundation of Shandong Province,No.ZR2021QH195 and No.ZR2020QH035.
文摘After being ingested and entering the human stomach,Helicobacter pylori(H.pylori)adopts several effective strategies to adhere to and colonize the gastric mucosa and move to different regions of the stomach to obtain more nutrients and escape from the harsher environments of the stomach,leading to acute infection and chronic gastritis,which is the basis of malignant gastric tumors.The endoscopic manifestations and pathological features of H.pylori infection are diverse and vary with the duration of infection.In this review,we describe the endoscopic manifestations of each stage of H.pylori gastritis and then reveal the potential mechanisms of bacterial intragastric colonization and migration from the perspective of endoscopists to provide direction for future research on the effective therapy and management of H.pylori infection.
基金Supported by National Natural Science Foundation of China,No.81370590
文摘AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.
文摘At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the biliary reconstruction after resection, almost all surgeons use Roux-en-Y hepaticojejunostomy. A viable alternative to Roux-en-Y reconstruction after radical resection of hilar cholangiocarcinoma has not yet been proposed. We report a case of performing duct-to-duct biliary reconstruction after radical resection of Bismuth Ⅲa hilar cholangiocarcinoma. End-to-end anastomosis between the left hepatic duct and the distal common bile duct was used for the biliary reconstruction, and a singlelayer continuous suture was performed along the bile duct using 5-0 prolene. The patient was discharged favorably without biliary fistula 2 wk later. Evidence for tumor recurrence was not found after an 18 mo follow- up. Performing bile duct end-to-end anastomosis in hilar cholangiocarcinoma can simplify the complex digestive tract reconstruction process.
基金Supported by National Natural Science Foundation of China,No.81370590
文摘AIM: To investigate the effect of carvedilol on angiogenesis and the underlying signaling pathways.METHODS: The effect of carvedilol on angiogenesis was examined using a human umbilical vascular endothelial cell(HUVEC) model. The effect of carvedilol on cell viability was measured by CCK8 assay. Flow cytometry was used to assess the effect of carvedilol on cell cycle progression. Cell migration, transwell migration and tube formation assays were performed to analyze the effect of carvedilol on HUVEC function. Vascular endothelial growth factor(VEGF) induced activation of HUVECs, which were pretreated with different carvedilol concentrations or none. Western blot analysis detected the phosphorylation levels of three cell signaling pathway proteins, VEGFR-2, Src, and extracellular signal-regulated kinase(ERK). The specific Src inhibitor PP2 was used to assess the role of Src in the VEGF-induced angiogenic pathway.RESULTS: Carvedilol inhibited HUVEC proliferation in a dose-dependent manner(IC50 = 38.5 mmol/L). The distribution of cells in the S phase decreased from 43.6% to 37.2%, 35.6% and 17.8% by 1, 5 and 10 μmol/L carvedilol for 24 h, respectively. Carvedilol(10 μmol/L) reduced VEGF-induced HUVEC migration from 67.54 ± 7.83 to 37.11 ± 3.533(P < 0.001). Carvedilol concentrations of 5 μmol/L and 10 μmol/L reduced cell invasion from 196.3% ± 18.76% to 114.0% ± 12.20% and 51.68% ± 8.28%, respectively. VEGFinduced tube formation was also reduced significantly by 5 μmol/L and 10 μmol/L carvedilol from 286.0 ± 36.72 to 135.7 ± 18.13(P < 0.05) and 80.27 ± 11.16(P < 0.01) respectively. We investigated several intracellular protein levels to determine the reason for these reductions. Treatment with 10 μmol/L carvedilol reduced VEGF-induced tyrosine phosphorylation of VEGFR-2 from 175.5% ± 8.54% to 52.67% ± 5.33%(P < 0.01). Additionally, 10 μmol/L carvedilol reduced VEGF-induced ERK 1/2 phosphorylation from 181.9% ± 18.61% to 56.45% ± 7.64%(P < 0.01). The VEGFinduced increase in Src kinase activity was alleviated by carvedilol [decreased from 141.8% ± 15.37% to 53.57 ± 7.18%(P < 0.01) and 47.04% ± 9.74%(P < 0.01) at concentrations of 5 and 10 μmol/L, respectively]. Pretreatment of HUVECs with Src kinase inhibitor almost completely prevented the VEGF-induced ERK upregulation [decreased from 213.2% ± 27.68% to 90.96% ± 17.16%(P < 0.01)].CONCLUSION: Carvedilol has an anti-angiogenic effect on HUVECs. This inhibitory effect is mediated by VEGF-induced Src-ERK signaling pathways.
文摘AIM: To assess whole-body fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the management of small bowel obstructions (SBOs) secondary to gastric cancer and its role in treatment strategies. METHODS: The medical records of all of the patients who were admitted for an intestinal obstruction after curative resection for gastric cancer were retrospectively reviewed. PET/CT was performed before a clinical treatment strategy was established for each patient. The patients were divided into 2 groups: patients with no evidence of a tumor recurrence and patients with evidence of a tumor recurrence. Tumor recurrences included a local recurrence, peritoneal carcinomatosis or distant metastases. The primary endpoint was the 1-year survival rate, and other variables included patient demographics, the length of hospital stay, complications, and mortality. RESULTS: The median time between a diagnosis of gastric cancer and the detection of a SBO was 1.4 years. Overall, 31 of 65 patients (47.7%) had evidence of a tumor recurrence on the PET/CT scan, which was the only factor that was associated with poor survival. Open and close surgery was the main type of surgical procedure reported for the patients with tumor recurrences. R0 resections were performed in 2 patients, including 1 who underwent combined adjacent organ resection. In the group with no evidence of a tumor recurrence on PET/CT, bowel resections were performed in 7 patients, adhesiolysis was performed in 7 patients, and a bypass was performed in 1 patient. The 1-year survival curves according to PET/CT evidence of a tumor recurrence vs no PET/CT evidence of a tumor recurrence were significantly different, and the 1-year survival rates were 8.8% vs 93.5%, respectively. There were no significant differences (P = 0.71) in the 1-year survival rates based on surgical vs nonsurgical management (0% with nonoperative treatment vs 20% after exploratory laparotomy). CONCLUSION: 18 F-FDG PET/CT can be used to identify the causes of bowel obstructions in patients with a history of gastric cancer, and this method is useful for planning the surgical management of these patients.
基金Project supported by the National Natural Science Foundation of China(Nos.51575378,11972245,and 11672187)。
文摘Phononic crystals(PCs) have recently been developed as effective components for vibration suppression and sound absorption. As a typical design of PCs, wave attenuation occurs in the so-called stop-band. However, the structural response is still significantly large in the pass-band. In this paper, we combine PCs and acoustic black holes(ABHs) in a unique device, achieving a versatile device that can attenuate vibration in the stop-band, while suppress vibration in the pass-band. This approach provides a versatile platform for controlling vibration in a multiband with a simple design.
基金supported by the National Natural Science Foundation of China (No. 51606180)
文摘A multi-objective optimization of non-uniform beams is presented for minimum radiated sound power and weight. The transfer matrix method is used to compute the structural and acoustic responses of a non-uniform beam accurately and efficiently. The multi-objective particle swarm optimization technique is applied to search the Pareto optimal solutions that represent various compromises between weight and sound radiation. Several constraints are imposed, which substantially reduce the volume fraction of feasible solutions in the design space. Two nonuniform beams with different boundary conditions are studied to demonstrate the multi-objective optimal designs of the structure.
基金Supported by the National Natural Science Foundation of China(Nos.11172197,11332008 and 11572215)the Natural Science Foundation of Tianjin through a key-project Grant(12JCZDJC30400)the UC MEXUS-CONACy T through the project Hybridizing Set Oriented Methods and Evolutionary Strategies to Obtain Fast and Reliable Multi-objective Optimization Algorithms
文摘In this paper, we investigate a multi-objective optimal design of a tuned vibration absorber for a two degrees-of-freedom linear system, in which we take white Gaussian noise as the excitation. We use the simple cell mapping method to obtain solutions to the multi-objective optimization problem. We optimize tuned vibration absorbers in two different configurations. As our objective,we take various features of the response of the power spectrum density function. Our results show that the primary mass vibration with the optimally designed absorber has a lower peak power spectrum value. In addition, the two natural frequencies of the optimized system are further apart than in the non-optimized system, which implies that the absorber has a wider effective region in the frequency domain.
基金Project supported by the National Natural Science Foundation of China(Nos.51275280 and51575325)
文摘The nonlinear resonance response of an electrostatically actuated nanobeam is studied over the near-half natural frequency with an axial capacitor controller. A graphene sensor deformed by the vibrations of the nanobeam is used to produce the voltage signal. The voltage of the vibration graphene sensor is used as a control signal input to a closed- loop circuit to mitigate the nonlinear vibration of the nanobeam. An axial control force produced by the axial capacitor controller can transform the frequency-amplitude curves from nonlinear to linear. The necessary and sufficient conditions for guaranteeing the system stability and a saddle-node bifurcation are studied. The numerical simulations are conducted for uniform nanobeams. The nonlinear terms of the vibration system can be transformed into linear ones by applying the critical control voltage to the system. The nonlinear vibration phenomena can be avoided, and the vibration amplitude is mitigated evidently with the axial capacitor controller.
基金Mianyang Science and Technology Planning Project Charter(No.15S-ZC-03)
文摘Objective:To study the effect of inhibiting high mobility group box 1(HMGB1)gene expression on ultrasonic blood flow characteristics,inflammatory response and apoptosis in diabetic retinopathy rats.Methods:Male SD rats were chosen and randomly divided into control group,model group and HMGB1 inhibition group,the latter two groups were given intraperitoneal injection of streptozotocin to establish the diabetes model,and HMGB1 group were given tail vein injection of HMGB1-shRNA lentivirus for intervention.The peak end-systolic velocity(PSV),peak end-diastolic velocity(EDV),resistance index(RI)and pulsatility index(PI)of central retinal artery as well as the HMGB1,bcl-2,bax and cleaved caspase-3 expression and TNF-α,MCP-1 and ICAM-1 contents in retinal tissues were measured at 4 weeks after intervention.Results:The PSV and EDV levels as well as bcl-2 expression in the model group were lower than those in the control group,while the RI and PI levels as well as HMGB1,bax and cleaved caspase-3 expression and TNF-α,MCP-1 and ICAM-1 contents were higher than those in the control group;the PSV and EDV levels as well as bcl-2 expression in the HMGB1 inhibition group were higher than those in the model group,while the RI and PI levels as well as HMGB1,bax and cleaved caspase-3 expression and TNF-α,MCP-1 and ICAM-1 contents were lower than those in the model group.Conclusion:Inhibition of HMGB1 gene expression can improve the blood flow of central retinal artery and inhibit the inflammatory response and apoptosis in diabetic retinopathy rats.
文摘Objective To evaluate the long-term outcome and prognostic factors of patients with nasopharyngeal carcinoma(NPC)from low-endemic regions of China who received definitive intensity-modulated radiation therapy(IMRT).Methods The clinical data from 608 patients with newly-diagnosed non-metastatic NPC who have received initial treatment at our cancer center from January,2008 to December,2013 were retrospectively reviewed.All patients received definitive IMRT,and 87.7%received platinum-based chemotherapy.Results The median follow-up duration was 51 months(follow-up rate,98.5%;range,10–106 months)for the entire cohort.The 5-year overall survival rate was 79.7%.The 5-year local relapse-free survival rate,regional relapse-free survival rate,distant metastasis-free survival rate and progression-free survival rate were 92.4%,93.3%,79.2%and 74.3%,respectively.A total of 153 patients had experienced treatment failure,with distant metastasis as the primary cause in 77.1%(118/153).Patients with T4 or N3 diseases had a significantly poorer prognosis than other subcategories.Stage T4 and N3 were closely associated with distant metastasis,with the metastatic rate of 29.3%and 45.5%,respectively.Conclusion IMRT provides patients with non-metastatic NPC with satisfactory long-term survival.Both T stage and N stage are important prognostic factors for NPC patients.Patients with T4 or N3 diseases have significantly increased distant metastatic rates and poor survival time.
基金Project supported by the National Natural Science Foundation of China (Nos. 12132010 and12021002)the Natural Science Foundation of Tianjin of China (No. 19JCZDJC38800)。
文摘The data-driven methods extract the feature information from data to build system models, which enable estimation and identification of the systems and can be utilized for prognosis and health management(PHM). However, most data-driven models are still black-box models that cannot be interpreted. In this study, we use the neural ordinary differential equations(ODEs), especially the inherent computational relationships of a system added to the loss function calculation, to approximate the governing equations. In addition, a new strategy for identifying the local parameters of the system is investigated, which can be utilized for system parameter identification and damage detection. The numerical and experimental examples presented in the paper demonstrate that the strategy has high accuracy and good local parameter identification. Moreover, the proposed method has the advantage of being interpretable. It can directly approximate the underlying governing dynamics and be a worthwhile strategy for system identification and PHM.
文摘BACKGROUND Oral lichen planus(OLP)is a chronic inflammatory disorder,and it can affect normal oral function.The conventional treatments for OLP are not always effective,and relapse easily occurs.Therefore,treatment of OLP is difficult and challenging.In this study,we evaluated over a long period the clinical efficacy of surgical excision and acellular dermal matrix(ADM)grafting in patients with refractory OLP.CASE SUMMARY Eleven patients with refractory OLP underwent a standardized protocol of surgical excision and ADM grafting.The condition of the area of the grafted wound,the intraoperative maximum mouth opening,pain,and clinical healing were assessed at postoperative follow-up visits.All patients had a flat surgical area with similar mucosal tissue coverage and local scar formation.Patients had no irritation and pain in their mucous membranes when eating acidic and spicy food.All patients’mouth openings returned to normal within 2-6 mo after surgery.During follow-up,none of the patients had recurrence of OLP after surgery.The longest follow-up was 11 yr and the shortest was 6 mo,and none of the patients relapsed during follow-up.CONCLUSION Surgical excision and ADM grafting could be an effective method to treat refractory OLP.
