BACKGROUND Situs inversus totalis(SIT)is a rare condition in which the positions of abdominal and thoracic organs present a“mirror image”of the normal ones in the median sagittal plane.Although minimally invasive su...BACKGROUND Situs inversus totalis(SIT)is a rare condition in which the positions of abdominal and thoracic organs present a“mirror image”of the normal ones in the median sagittal plane.Although minimally invasive surgery has evolved to achieve laparoscopic gastrectomy for gastric cancer(GC)patients with SIT,it is difficult to perform lymphadenectomy(LND)in such a transposed anatomical condition.Herein,we report the cases of two patients with SIT who successfully underwent laparoscopy-assisted gastrectomy(LAG)with D2 LND.CASE SUMMARY Case 1:A 65-year-old man was admitted for intermittent abdominal pain and distension,occasional belching,and acid reflux for 4 mo.He was diagnosed with GC(cT3N1-2M0)with SIT.Before surgery,he had undergone four cycles of neoadjuvant chemotherapy and immunotherapy.Then,the patient was evaluated as having a partial response,and laparoscopy-assisted distal gastrectomy with D2 LND and Billroth II reconstruction were performed.The operation was performed successfully within 240 min with an estimated blood loss of 50 mL and no severe complications.The patient was discharged on postoperative day(POD)9.Case 2:A 55-year-old man was admitted for upper abdominal distension with pain and discomfort after eating for 3 mo.He was diagnosed with GC(cT3N1M0)with SIT.He had a history of hypertension for more than 10 years;however,his blood pressure was well-controlled via regular medication.We performed laparoscopy-assisted total gastrectomy with D2 LND and Roux-en-Y reconstruction.The operation was performed successfully within 168 min with an estimated blood loss of 50 mL and no severe complications.The patient was discharged on POD 10.CONCLUSION LAG with D2 LND could be considered an accessible,safe,and curative procedure for advanced GC patients with SIT.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is one of the most frequent cancers and the main cause of cancer-related death worldwide.Ectopic HCC,an extremely rare type of HCC,exhibits a wide range of clinical signs and ra...BACKGROUND Hepatocellular carcinoma(HCC)is one of the most frequent cancers and the main cause of cancer-related death worldwide.Ectopic HCC,an extremely rare type of HCC,exhibits a wide range of clinical signs and radiographic features,making preoperative identification challenging.CASE SUMMARY A 47-year-old man underwent routine abdominal color ultrasonography,which identified an asymptomatic tumor in the left upper abdomen.The patient had no history of hepatitis,did not drink alcohol,and had no family history of cancer.Abdominal contrast-enhanced computed tomography(CT)revealed a heterogeneously enhanced lesion between the spleen and stomach that had invaded the diaphragm,with blood supplied by the left inferior phrenic artery.The patient underwent laparoscopic surgery,and HCC was identified by postoperative pathology.Additionally,specific immunohistochemical staining was performed to assess the molecular biological characteristics of the HCC.The patient underwent two rounds of hepatic arterial interventional chemotherapy after surgery.Abdominal plain and enhanced magnetic resonance imaging and lung CT 3 mo postoperatively revealed no signs of local recurrence or distant metastasis.CONCLUSION This asymptomatic ectopic HCC case described achieved an excellent result due to early detection,radical resection,and systematic surveillance.展开更多
AIM: To investigate the changes of methylation state and expression of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823 which were treated in vitro with demethlylating agent 5-Aza-CdR in combination ...AIM: To investigate the changes of methylation state and expression of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823 which were treated in vitro with demethlylating agent 5-Aza-CdR in combination with histone deacetylase inhibitor NaB. METHODS: After SGC7901 and BGC823 cells were treated with 5-Aza-CdR and/or NaB,the methylation state of RASSF1A gene was detected by methylation-specific PCR,and the changes in expression of mRNA and protein level of RASSF1A gene were observed by RT-PCR and Western-blotting before and after drug treatment. RESULTS: Hypermethylation was detected in the promoter region of RASSF1A gene in both SGC7901 and BGC823 cells,and there was no expression of this gene at both mRNA and protein level. After treatment with 5-Aza-CdR,demethylation occurred in the promoter region of RASSF1A gene,which subsequently induced re-expression of this gene. The treatment with NaB alone showed no effect on the methylation state and expression of RASSF1A gene. The combined treatment of 5-Aza-CdR and NaB induced complete demethylation of RASSF1A gene,leading to a significantly higher re-expression of the mRNA and protein of RASSF1A than those treated with 5-Aza-CdR alone (P < 0.05). CONCLUSION: Hypermethylation in the promoter region is related to inactivation of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823,while demethlylating agent 5-Aza-CdR can reverse the methylation state of RASSF1A gene and induce its re-expression. Histone deacetylase inhibitor NaB had a synergistic effect with 5-Aza-CdR in both demethylation and gene transcriptional regulation.展开更多
BACKGROUND Noninvasive biomarkers have been developed to predict hepatitis B virus(HBV)related fibrosis owing to the significant limitations of liver biopsy.Both serum biomarkers and imaging techniques have shown prom...BACKGROUND Noninvasive biomarkers have been developed to predict hepatitis B virus(HBV)related fibrosis owing to the significant limitations of liver biopsy.Both serum biomarkers and imaging techniques have shown promising results and may improve the evaluation of liver fibrosis.However,most of the previous studies focused on the diagnostic effects of various imaging techniques on fibrosis in all chronic liver diseases.AIM To compare the performance of common imaging methods and serum biomarkers for prediction of significant fibrosis caused only by HBV infection.METHODS A systematic review was conducted on the records available in PubMed,EMBASE,and the Cochrane Library electronic databases until December 2018.We systematically assessed the effectiveness of two serum biomarkers and three imagine techniques in predicting significant fibrosis solely caused by HBV infection.The serum biomarkers included aspartate aminotransferase-to-platelet ratio index(APRI)and fibrosis index based on the 4 factors(FIB-4).The three imaging techniques included acoustic radiation force impulse(ARFI),FibroScan,and magnetic resonance elastography(MRE).Three parameters,the area under the summary receiver operating characteristic curve(AUSROC),the summary diagnostic odds ratio,and the summary sensitivity and specificity,were used to examine the accuracy of all tests for liver fibrosis.RESULTS Out of 2831 articles evaluated for eligibility,204 satisfied the predetermined inclusion criteria for this current meta-analysis.Eventually,our final data contained 81 studies.The AUSROCs of serum biomarkers of APRI and FIB-4 were both 0.75.For imaging techniques(ARFI,FibroScan,and MRE),the areas were 0.89,0.83,and 0.97,respectively.The heterogeneities of ARFI and FibroScan were statistically significant(I2>50%).The publication bias was not observed in any of the serum biomarkers or imaging methods.CONCLUSION These five methods have attained an acceptable level of diagnostic accuracy.Imaging techniques,MRE in particular,demonstrate significant advantages in accurately predicting HBV-related significant fibrosis,while serum biomarkers are admissible methods.展开更多
The Jiaodong Peninsula in Shandong Province,China is the world’s third-largest gold metallogenic area,with cumulative proven gold resources exceeding 5000 t.Over the past few years,breakthroughs have been made in dee...The Jiaodong Peninsula in Shandong Province,China is the world’s third-largest gold metallogenic area,with cumulative proven gold resources exceeding 5000 t.Over the past few years,breakthroughs have been made in deep prospecting at a depth of 500‒2000 m,particularly in the Sanshandao area where a huge deep gold orebody was identified.Based on previous studies and the latest prospecting progress achieved by the project team of this study,the following results are summarized.(1)3D geological modeling results based on deep drilling core data reveal that the Sanshandao gold orefield,which was previously considered to consist of several independent deposits,is a supergiant deposit with gold resources of more than 1200 t(including 470 t under the sea area).The length of the major orebody is nearly 8 km,with a greatest depth of 2312 m below sea level and a maximum length of more than 3 km along their dip direction.(2)Thick gold orebodies in the Sanshandao gold deposit mainly occur in the specific sections of the ore-controlling fault where the fault plane changes from steeply to gently inclined,forming a stepped metallogenic model from shallow to deep level.The reason for this strong structural control on mineralization forms is that when ore-forming fluids migrated along faults,the pressure of fluids greatly fluctuated in fault sections where the fault dip angle changed.Since the solubility of gold in the ore-forming fluid is sensitive to fluid pressure,these sections along the fault plane serve as the target areas for deep prospecting.(3)Thermal uplifting-extensional structures provide thermodynamic conditions,migration pathways,and deposition spaces for gold mineralization.Meanwhile,the changes in mantle properties induced the transformation of the geochemical properties of the lower crust and magmatic rocks.This further led to the reactivation of ore-forming elements,which provided rich materials for gold mineralization.(4)It can be concluded from previous research results that the gold mineralization in the Jiaodong gold deposits occurred at about 120 Ma,which was superimposed by nonferrous metals mineralization at 118‒111 Ma.The fluids were dominated by primary mantle water or magmatic water.Metamorphic water occurred in the early stage of the gold mineralization,while the fluid composition was dominated by meteoric water in the late stage.The S,Pb,and Sr isotopic compositions of the ores are similar to those of ore-hosting rocks,indicating that the ore-forming materials mainly derive from crustal materials,with the minor addition of mantle-derived materials.The gold deposits in the Jiaodong Peninsula were formed in an extensional tectonic environment during the transformation of the physical and chemical properties of the lithospheric mantle,which is different from typical orogenic gold deposits.Thus,it is proposed that they are named“Jiaodong-type”gold deposits.展开更多
Dongping Lake area,located in the lower reaches of Yellow River,is an ideal place to study the changes of modern river and lake sedimentary environment.The sediment samples of Dawen River,Yellow River,and Dongping Lak...Dongping Lake area,located in the lower reaches of Yellow River,is an ideal place to study the changes of modern river and lake sedimentary environment.The sediment samples of Dawen River,Yellow River,and Dongping Lake were collected,and the major elements,trace elements and organic matter geochemical composition of the samples were analyzed.Cluster analysis,characteristic element ratio method and graphic method were used to explore the geochemical characteristics of sediments and their environmental implication.The results show that the contents of SiO_(2),Na_(2)O,TiO_(2) and Zr in sediments of Dawen River and Yellow River are relatively high,and the contents of iron and manganese oxides,organic matter,CaO,P2O5 and Sr in lake sediments are relatively high.That reveals the differences of sedimentary environments between the rivers and the lake.The contents of Sr and Zr in Dawen River are affected by the rapid migration of clastic materials in the upstream carbonate source area during the flood season;the δCe,ΣREE and REE’s ratios in the sediments of the Yellow River reflect the influence of the Loess source;and the distribution of elements changes along the flow direction during the flood season.The characteristics of pH,element composition and LREE&HREE fractionation of the lake sediments indicate that the sediment source is complex,and the lake environment is affected by the flood season.The study shows that the geochemical content and its variation characteristics of sediments effectively reveal the sedimentary environment,material composition and characteristics of flood season of rivers and the lake in the study area.展开更多
Objective:To investigate the effects of Xinjikang on the left ventricular hypertrophy remodeling and myocardial activity in hypertension.Methods:Sixty Wistar rats were randomly divided into four groups.The pressure-lo...Objective:To investigate the effects of Xinjikang on the left ventricular hypertrophy remodeling and myocardial activity in hypertension.Methods:Sixty Wistar rats were randomly divided into four groups.The pressure-loaded left ventricular hypertrophy model was established with abdominal aorta ligation method.Rats in A and B groups were intragastrically administered with physiological saline,while C and D groups were administered with Xinjikang and metoprolol,respectively.The changes in blood pressure.E/A ratio,myocardial pathological morphology,myocardial lipoperoxides and superoxide dismustase activity in four groups were observed and compared before and after treatment.Results:There were statistically significant differences in E/A ratio between C group after treatment and model group(P<0.05).while no difference was observed between A and D groups(P>0.05);after treatment the myocardial lipoperoxides and superoxide dismustase contents in C and D groups were improved significantly compared with model group(P<0.05).Conclusions:Xinjikang can improve myocardial injury,restore myocardial parenchyma and myocardial interstitial remodeling functions in hypertensive rats with the left ventricular hypertrophy.展开更多
Background:Study the effect of Jiangu Shenjin decoction on the Wnt/β-catenin signalling pathway in knee osteoarthritis.Methods:Forty-eight female Sprague-Dawley rats were randomly divided into eight groups.After succ...Background:Study the effect of Jiangu Shenjin decoction on the Wnt/β-catenin signalling pathway in knee osteoarthritis.Methods:Forty-eight female Sprague-Dawley rats were randomly divided into eight groups.After successful modelling,the blank group and the model group were given a normal diet and drinking water,and the other rats were given meloxicam,an anti-bone hyperplasia agent and Jiangu Shenjin decoction by gavage for 4 weeks.The degree of movement and knee swelling were observed.Serum levels of interleukin-1β,interleukin-6,and tumour necrosis factor-αwere measured.The levels of inflammatory factors,pathological changes in articular cartilage and the mRNA expression levels ofβ-catenin and Wnt4 were examined.Results:Compared with the model group,the treatment group had lower levels than the model group.The medium-dose group had lower levels than the high-dose group.Compared with the meloxicam group and the anti-bone hyperplasia group,the medium-dose group had lower levels than the high-dose group.The medium-dose group had slightly lower levels than the other two groups,and the difference among the three groups was not significant.The mRNA expression level of Wnt4 andβ-catenin indicated thatβ-catenin was inhibited in the signalling pathway.The level ofβ-catenin was inhibited and then increased each treatment,and bone metabolism regulation by Jiangu Shenjin decoction was effective.Conclusion:Jiangu Shenjin decoction may act through Wnt to treat knee osteoarthritis.Theβ-catenin signalling pathway inhibits inflammatory factors and regulates proteins in the signalling pathway to affect bone metabolism.展开更多
Dear Editors,Alzheimer’s disease(AD)and vascular dementia(VaD)are two of the most common forms of dementia,resulting in increased disability and mortality,impaired quality of life,and serious burdens on society and c...Dear Editors,Alzheimer’s disease(AD)and vascular dementia(VaD)are two of the most common forms of dementia,resulting in increased disability and mortality,impaired quality of life,and serious burdens on society and caregivers.However,the presently available drugs can only alleviate symptoms for a short time without delaying the progression of the cognitive disorders.Since 2003,no new drugs have been approved by the US Food and Drug Administration for the treatment of AD.In 2019,phase III clinical trials of crenezumab and aducanumab,two anti-amyloid beta monoclonal antibodies,were terminated.The scant progress in clinical trials urges efforts towards an alternative therapeutic strategy for dementia.展开更多
Isothermal thermo-gravimetric analysis was applied to investigate the nitridation kinetics of manganese powder with different particle sizes at 800,900 and 1 000℃.The apparent activation energy and nitridation kineti...Isothermal thermo-gravimetric analysis was applied to investigate the nitridation kinetics of manganese powder with different particle sizes at 800,900 and 1 000℃.The apparent activation energy and nitridation kinetics equations of manganese powder with different particle sizes were obtained from unreacted shrinking core model and Arrhenius formula.It was found that the nitridation mechanism was controlled by interfacial chemical reaction.The apparent activation energy and the apparent rate constant of nitridation reaction were affected by particle sizes.With the decrease of particle size,the apparent activation energy decreased whilst the apparent rate constant increased.It was suggested that the refinement of the manganese powder contributed to the increase of molar surface energy,which accounted for the lower apparent activation energy.展开更多
Estimation of unknown parameters in exponential models by linear and nonlinear fitting methods is discussed. Based on the extreme value theorem and Taylor series expansion, it is proved theoretically that the paramete...Estimation of unknown parameters in exponential models by linear and nonlinear fitting methods is discussed. Based on the extreme value theorem and Taylor series expansion, it is proved theoretically that the parameters estimated by the linear fitting method alone cannot minimize the sum of the squared residual errors in the measurement data when measurement noise is involved in the data. Numerical simulation is performed to compare the performance of the linear and nonlinear fitting methods. Simulation results show that the linear method can obtain only a suboptimal estimate of the unknown parameters and that the nonlinear method gives more accurate results. Application of the fitting methods is demonstrated where the water spectral attenuation coefficient is estimated from underwater images and imaging distances, which supports the improvement in the accuracy of parameter estimation by the nonlinear fitting method.展开更多
The effects of Ca treatment on the particle, microstructure, and toughness of heat-affected zone (HAZ) of shipbuilding steel with Zr-Ti deoxidation after high-heat-input welding were investigated. The simulated weldin...The effects of Ca treatment on the particle, microstructure, and toughness of heat-affected zone (HAZ) of shipbuilding steel with Zr-Ti deoxidation after high-heat-input welding were investigated. The simulated welding at a high-heat-input welding of 200 kJ/cm was carried out using Gleeble-3800 welding simulation. Then, particle characteristics were characterized using an Aztec-Feature automatic particle analysis system. Additionally, an in-situ observation experiment was performed to study the relationships between particle and microstructure by high-temperature confocal laser scanning microscopy (HT-CLSM). The results indicated that the average HAZ toughness at -40 ℃ was increased from 183 to 290 J by adding 0.0026 wt.% Ca. Meanwhile, the formation of acicular ferrite ratio was increased from 49.34% to 60.28% due to the addition of Ca. The scanning electron microscopy results clearly showed that CaO-Al_(2)O_(3)-TiOx-ZrO_(2)-MnS particles could act as effective nucleation sites for the formation of acicular ferrite, which has been verified by the observation of the particle-microstructure relationship under HT-CLSM. Furthermore, particle characterization results show that the cumulative frequency of particles with the size of 1-3 lm was 33.2% in HAZ of Zr-Ti shipbuilding steel but 66.2% in HAZ of Zr-Ti-Ca shipbuilding steel.展开更多
Dear Editor,While most of the patients infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)cleared the virus within a few weeks of infection,some people have a persistent infection or persistent s...Dear Editor,While most of the patients infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)cleared the virus within a few weeks of infection,some people have a persistent infection or persistent shedding viral RNA in the long term.The persistent detection of viral RNA in clinical specimens is unlikely to reflect either relapse or reinfection in most cases because the replication-competent virus is generally not recoverable after ten days following symptom onset in mild to moderate cases of COVID-191 and after 20 days in severe or immunocompromised cases.展开更多
基金Supported by National Natural Science Foundation of China,No.81401515Zhongnan Hospital of Wuhan University Science Technology and Innovation Seed Fund,No.znpy2018030“351Talent Project(Luojia Young Scholars)”of Wuhan University.
文摘BACKGROUND Situs inversus totalis(SIT)is a rare condition in which the positions of abdominal and thoracic organs present a“mirror image”of the normal ones in the median sagittal plane.Although minimally invasive surgery has evolved to achieve laparoscopic gastrectomy for gastric cancer(GC)patients with SIT,it is difficult to perform lymphadenectomy(LND)in such a transposed anatomical condition.Herein,we report the cases of two patients with SIT who successfully underwent laparoscopy-assisted gastrectomy(LAG)with D2 LND.CASE SUMMARY Case 1:A 65-year-old man was admitted for intermittent abdominal pain and distension,occasional belching,and acid reflux for 4 mo.He was diagnosed with GC(cT3N1-2M0)with SIT.Before surgery,he had undergone four cycles of neoadjuvant chemotherapy and immunotherapy.Then,the patient was evaluated as having a partial response,and laparoscopy-assisted distal gastrectomy with D2 LND and Billroth II reconstruction were performed.The operation was performed successfully within 240 min with an estimated blood loss of 50 mL and no severe complications.The patient was discharged on postoperative day(POD)9.Case 2:A 55-year-old man was admitted for upper abdominal distension with pain and discomfort after eating for 3 mo.He was diagnosed with GC(cT3N1M0)with SIT.He had a history of hypertension for more than 10 years;however,his blood pressure was well-controlled via regular medication.We performed laparoscopy-assisted total gastrectomy with D2 LND and Roux-en-Y reconstruction.The operation was performed successfully within 168 min with an estimated blood loss of 50 mL and no severe complications.The patient was discharged on POD 10.CONCLUSION LAG with D2 LND could be considered an accessible,safe,and curative procedure for advanced GC patients with SIT.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is one of the most frequent cancers and the main cause of cancer-related death worldwide.Ectopic HCC,an extremely rare type of HCC,exhibits a wide range of clinical signs and radiographic features,making preoperative identification challenging.CASE SUMMARY A 47-year-old man underwent routine abdominal color ultrasonography,which identified an asymptomatic tumor in the left upper abdomen.The patient had no history of hepatitis,did not drink alcohol,and had no family history of cancer.Abdominal contrast-enhanced computed tomography(CT)revealed a heterogeneously enhanced lesion between the spleen and stomach that had invaded the diaphragm,with blood supplied by the left inferior phrenic artery.The patient underwent laparoscopic surgery,and HCC was identified by postoperative pathology.Additionally,specific immunohistochemical staining was performed to assess the molecular biological characteristics of the HCC.The patient underwent two rounds of hepatic arterial interventional chemotherapy after surgery.Abdominal plain and enhanced magnetic resonance imaging and lung CT 3 mo postoperatively revealed no signs of local recurrence or distant metastasis.CONCLUSION This asymptomatic ectopic HCC case described achieved an excellent result due to early detection,radical resection,and systematic surveillance.
基金The National Natural Science Foundation of China, No. 30572162, No. 30271477The Special Scientific Research Fundation for Doctors, State Education Ministry,No.20050159001
文摘AIM: To investigate the changes of methylation state and expression of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823 which were treated in vitro with demethlylating agent 5-Aza-CdR in combination with histone deacetylase inhibitor NaB. METHODS: After SGC7901 and BGC823 cells were treated with 5-Aza-CdR and/or NaB,the methylation state of RASSF1A gene was detected by methylation-specific PCR,and the changes in expression of mRNA and protein level of RASSF1A gene were observed by RT-PCR and Western-blotting before and after drug treatment. RESULTS: Hypermethylation was detected in the promoter region of RASSF1A gene in both SGC7901 and BGC823 cells,and there was no expression of this gene at both mRNA and protein level. After treatment with 5-Aza-CdR,demethylation occurred in the promoter region of RASSF1A gene,which subsequently induced re-expression of this gene. The treatment with NaB alone showed no effect on the methylation state and expression of RASSF1A gene. The combined treatment of 5-Aza-CdR and NaB induced complete demethylation of RASSF1A gene,leading to a significantly higher re-expression of the mRNA and protein of RASSF1A than those treated with 5-Aza-CdR alone (P < 0.05). CONCLUSION: Hypermethylation in the promoter region is related to inactivation of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823,while demethlylating agent 5-Aza-CdR can reverse the methylation state of RASSF1A gene and induce its re-expression. Histone deacetylase inhibitor NaB had a synergistic effect with 5-Aza-CdR in both demethylation and gene transcriptional regulation.
基金Supported by Social Science Foundation of Liaoning Province,No.L18ATJ001
文摘BACKGROUND Noninvasive biomarkers have been developed to predict hepatitis B virus(HBV)related fibrosis owing to the significant limitations of liver biopsy.Both serum biomarkers and imaging techniques have shown promising results and may improve the evaluation of liver fibrosis.However,most of the previous studies focused on the diagnostic effects of various imaging techniques on fibrosis in all chronic liver diseases.AIM To compare the performance of common imaging methods and serum biomarkers for prediction of significant fibrosis caused only by HBV infection.METHODS A systematic review was conducted on the records available in PubMed,EMBASE,and the Cochrane Library electronic databases until December 2018.We systematically assessed the effectiveness of two serum biomarkers and three imagine techniques in predicting significant fibrosis solely caused by HBV infection.The serum biomarkers included aspartate aminotransferase-to-platelet ratio index(APRI)and fibrosis index based on the 4 factors(FIB-4).The three imaging techniques included acoustic radiation force impulse(ARFI),FibroScan,and magnetic resonance elastography(MRE).Three parameters,the area under the summary receiver operating characteristic curve(AUSROC),the summary diagnostic odds ratio,and the summary sensitivity and specificity,were used to examine the accuracy of all tests for liver fibrosis.RESULTS Out of 2831 articles evaluated for eligibility,204 satisfied the predetermined inclusion criteria for this current meta-analysis.Eventually,our final data contained 81 studies.The AUSROCs of serum biomarkers of APRI and FIB-4 were both 0.75.For imaging techniques(ARFI,FibroScan,and MRE),the areas were 0.89,0.83,and 0.97,respectively.The heterogeneities of ARFI and FibroScan were statistically significant(I2>50%).The publication bias was not observed in any of the serum biomarkers or imaging methods.CONCLUSION These five methods have attained an acceptable level of diagnostic accuracy.Imaging techniques,MRE in particular,demonstrate significant advantages in accurately predicting HBV-related significant fibrosis,while serum biomarkers are admissible methods.
基金by the NSFC-Shandong Joint Fund Program entitled“Control Mechanisms of Faults on Deep Gold Deposits in Jiaodong Peninsula”(U2006201).
文摘The Jiaodong Peninsula in Shandong Province,China is the world’s third-largest gold metallogenic area,with cumulative proven gold resources exceeding 5000 t.Over the past few years,breakthroughs have been made in deep prospecting at a depth of 500‒2000 m,particularly in the Sanshandao area where a huge deep gold orebody was identified.Based on previous studies and the latest prospecting progress achieved by the project team of this study,the following results are summarized.(1)3D geological modeling results based on deep drilling core data reveal that the Sanshandao gold orefield,which was previously considered to consist of several independent deposits,is a supergiant deposit with gold resources of more than 1200 t(including 470 t under the sea area).The length of the major orebody is nearly 8 km,with a greatest depth of 2312 m below sea level and a maximum length of more than 3 km along their dip direction.(2)Thick gold orebodies in the Sanshandao gold deposit mainly occur in the specific sections of the ore-controlling fault where the fault plane changes from steeply to gently inclined,forming a stepped metallogenic model from shallow to deep level.The reason for this strong structural control on mineralization forms is that when ore-forming fluids migrated along faults,the pressure of fluids greatly fluctuated in fault sections where the fault dip angle changed.Since the solubility of gold in the ore-forming fluid is sensitive to fluid pressure,these sections along the fault plane serve as the target areas for deep prospecting.(3)Thermal uplifting-extensional structures provide thermodynamic conditions,migration pathways,and deposition spaces for gold mineralization.Meanwhile,the changes in mantle properties induced the transformation of the geochemical properties of the lower crust and magmatic rocks.This further led to the reactivation of ore-forming elements,which provided rich materials for gold mineralization.(4)It can be concluded from previous research results that the gold mineralization in the Jiaodong gold deposits occurred at about 120 Ma,which was superimposed by nonferrous metals mineralization at 118‒111 Ma.The fluids were dominated by primary mantle water or magmatic water.Metamorphic water occurred in the early stage of the gold mineralization,while the fluid composition was dominated by meteoric water in the late stage.The S,Pb,and Sr isotopic compositions of the ores are similar to those of ore-hosting rocks,indicating that the ore-forming materials mainly derive from crustal materials,with the minor addition of mantle-derived materials.The gold deposits in the Jiaodong Peninsula were formed in an extensional tectonic environment during the transformation of the physical and chemical properties of the lithospheric mantle,which is different from typical orogenic gold deposits.Thus,it is proposed that they are named“Jiaodong-type”gold deposits.
基金This study was supported by Opening Fund of Provincial Key Lab of Applied Nuclear Techniques in Geosciences(No.201904)Key Scientific and Technological Project(No.KY201957)of Shandong Bureau of Geology and Mineral Resources.
文摘Dongping Lake area,located in the lower reaches of Yellow River,is an ideal place to study the changes of modern river and lake sedimentary environment.The sediment samples of Dawen River,Yellow River,and Dongping Lake were collected,and the major elements,trace elements and organic matter geochemical composition of the samples were analyzed.Cluster analysis,characteristic element ratio method and graphic method were used to explore the geochemical characteristics of sediments and their environmental implication.The results show that the contents of SiO_(2),Na_(2)O,TiO_(2) and Zr in sediments of Dawen River and Yellow River are relatively high,and the contents of iron and manganese oxides,organic matter,CaO,P2O5 and Sr in lake sediments are relatively high.That reveals the differences of sedimentary environments between the rivers and the lake.The contents of Sr and Zr in Dawen River are affected by the rapid migration of clastic materials in the upstream carbonate source area during the flood season;the δCe,ΣREE and REE’s ratios in the sediments of the Yellow River reflect the influence of the Loess source;and the distribution of elements changes along the flow direction during the flood season.The characteristics of pH,element composition and LREE&HREE fractionation of the lake sediments indicate that the sediment source is complex,and the lake environment is affected by the flood season.The study shows that the geochemical content and its variation characteristics of sediments effectively reveal the sedimentary environment,material composition and characteristics of flood season of rivers and the lake in the study area.
文摘Objective:To investigate the effects of Xinjikang on the left ventricular hypertrophy remodeling and myocardial activity in hypertension.Methods:Sixty Wistar rats were randomly divided into four groups.The pressure-loaded left ventricular hypertrophy model was established with abdominal aorta ligation method.Rats in A and B groups were intragastrically administered with physiological saline,while C and D groups were administered with Xinjikang and metoprolol,respectively.The changes in blood pressure.E/A ratio,myocardial pathological morphology,myocardial lipoperoxides and superoxide dismustase activity in four groups were observed and compared before and after treatment.Results:There were statistically significant differences in E/A ratio between C group after treatment and model group(P<0.05).while no difference was observed between A and D groups(P>0.05);after treatment the myocardial lipoperoxides and superoxide dismustase contents in C and D groups were improved significantly compared with model group(P<0.05).Conclusions:Xinjikang can improve myocardial injury,restore myocardial parenchyma and myocardial interstitial remodeling functions in hypertensive rats with the left ventricular hypertrophy.
基金the General Project of the Natural Science Foundation of Hainan Province(No.819MS064).
文摘Background:Study the effect of Jiangu Shenjin decoction on the Wnt/β-catenin signalling pathway in knee osteoarthritis.Methods:Forty-eight female Sprague-Dawley rats were randomly divided into eight groups.After successful modelling,the blank group and the model group were given a normal diet and drinking water,and the other rats were given meloxicam,an anti-bone hyperplasia agent and Jiangu Shenjin decoction by gavage for 4 weeks.The degree of movement and knee swelling were observed.Serum levels of interleukin-1β,interleukin-6,and tumour necrosis factor-αwere measured.The levels of inflammatory factors,pathological changes in articular cartilage and the mRNA expression levels ofβ-catenin and Wnt4 were examined.Results:Compared with the model group,the treatment group had lower levels than the model group.The medium-dose group had lower levels than the high-dose group.Compared with the meloxicam group and the anti-bone hyperplasia group,the medium-dose group had lower levels than the high-dose group.The medium-dose group had slightly lower levels than the other two groups,and the difference among the three groups was not significant.The mRNA expression level of Wnt4 andβ-catenin indicated thatβ-catenin was inhibited in the signalling pathway.The level ofβ-catenin was inhibited and then increased each treatment,and bone metabolism regulation by Jiangu Shenjin decoction was effective.Conclusion:Jiangu Shenjin decoction may act through Wnt to treat knee osteoarthritis.Theβ-catenin signalling pathway inhibits inflammatory factors and regulates proteins in the signalling pathway to affect bone metabolism.
基金We appreciate funding by the National Natural Science Foundation of China(Grant No.31171369)the National Basic Research Program(973 Program)(Nos 2011CB910903 and 2010CB912001)+1 种基金the Chinese Academy of Sciences(Hundred Talents Program and 2009OHTP10)the Joint Construction Project of Henan Province(No.2018020114 and No.2018020088),and the First Affiliated Hospital of Zhengzhou University.
文摘Dear Editors,Alzheimer’s disease(AD)and vascular dementia(VaD)are two of the most common forms of dementia,resulting in increased disability and mortality,impaired quality of life,and serious burdens on society and caregivers.However,the presently available drugs can only alleviate symptoms for a short time without delaying the progression of the cognitive disorders.Since 2003,no new drugs have been approved by the US Food and Drug Administration for the treatment of AD.In 2019,phase III clinical trials of crenezumab and aducanumab,two anti-amyloid beta monoclonal antibodies,were terminated.The scant progress in clinical trials urges efforts towards an alternative therapeutic strategy for dementia.
基金Sponsored by National Natural Science Foundation of China(51374023)
文摘Isothermal thermo-gravimetric analysis was applied to investigate the nitridation kinetics of manganese powder with different particle sizes at 800,900 and 1 000℃.The apparent activation energy and nitridation kinetics equations of manganese powder with different particle sizes were obtained from unreacted shrinking core model and Arrhenius formula.It was found that the nitridation mechanism was controlled by interfacial chemical reaction.The apparent activation energy and the apparent rate constant of nitridation reaction were affected by particle sizes.With the decrease of particle size,the apparent activation energy decreased whilst the apparent rate constant increased.It was suggested that the refinement of the manganese powder contributed to the increase of molar surface energy,which accounted for the lower apparent activation energy.
基金Project supported by the National Natural Science Foundation of China(Nos.61605038 and 11304278)the National High-Tech R&D Program(863)of China(No.2014AA093400)the Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics(No.SOED1606)
文摘Estimation of unknown parameters in exponential models by linear and nonlinear fitting methods is discussed. Based on the extreme value theorem and Taylor series expansion, it is proved theoretically that the parameters estimated by the linear fitting method alone cannot minimize the sum of the squared residual errors in the measurement data when measurement noise is involved in the data. Numerical simulation is performed to compare the performance of the linear and nonlinear fitting methods. Simulation results show that the linear method can obtain only a suboptimal estimate of the unknown parameters and that the nonlinear method gives more accurate results. Application of the fitting methods is demonstrated where the water spectral attenuation coefficient is estimated from underwater images and imaging distances, which supports the improvement in the accuracy of parameter estimation by the nonlinear fitting method.
基金supported by the Open Project Program of Bejing Key Laboratory of Pipeline Critical Technology and Equipment forDeepwater Oil&Gas Development(Grant No.BIPT2019001)the Natural Science Foundation of Hebei Province(Grant No.E2021318004)。
文摘The effects of Ca treatment on the particle, microstructure, and toughness of heat-affected zone (HAZ) of shipbuilding steel with Zr-Ti deoxidation after high-heat-input welding were investigated. The simulated welding at a high-heat-input welding of 200 kJ/cm was carried out using Gleeble-3800 welding simulation. Then, particle characteristics were characterized using an Aztec-Feature automatic particle analysis system. Additionally, an in-situ observation experiment was performed to study the relationships between particle and microstructure by high-temperature confocal laser scanning microscopy (HT-CLSM). The results indicated that the average HAZ toughness at -40 ℃ was increased from 183 to 290 J by adding 0.0026 wt.% Ca. Meanwhile, the formation of acicular ferrite ratio was increased from 49.34% to 60.28% due to the addition of Ca. The scanning electron microscopy results clearly showed that CaO-Al_(2)O_(3)-TiOx-ZrO_(2)-MnS particles could act as effective nucleation sites for the formation of acicular ferrite, which has been verified by the observation of the particle-microstructure relationship under HT-CLSM. Furthermore, particle characterization results show that the cumulative frequency of particles with the size of 1-3 lm was 33.2% in HAZ of Zr-Ti shipbuilding steel but 66.2% in HAZ of Zr-Ti-Ca shipbuilding steel.
基金grants from the Beijing Natural Science Foundation(L202038 to M.J.M.)the Natural Science Foundation of China(81621005 to W.C.C.)the National Major Project for Control and Prevention of Infectious Disease of China(2018ZX10101003-001-002 to H.B.S.).
文摘Dear Editor,While most of the patients infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)cleared the virus within a few weeks of infection,some people have a persistent infection or persistent shedding viral RNA in the long term.The persistent detection of viral RNA in clinical specimens is unlikely to reflect either relapse or reinfection in most cases because the replication-competent virus is generally not recoverable after ten days following symptom onset in mild to moderate cases of COVID-191 and after 20 days in severe or immunocompromised cases.
