BACKGROUND Esophageal cancer is a significant global health concern,characterized by high mortality rates and diverse histological types,primarily adenocarcinoma and squamous cell carcinoma.AIM To analyze trends in es...BACKGROUND Esophageal cancer is a significant global health concern,characterized by high mortality rates and diverse histological types,primarily adenocarcinoma and squamous cell carcinoma.AIM To analyze trends in esophageal cancer using Surveillance,Epidemiology,and End Results(SEER)data,focusing on patient characteristics,stage at diagnosis,treatment modalities,and survival outcomes,to provide insights that may guide clinical practice and public health initiatives.METHODS Age-adjusted incidence and mortality rates for esophageal cancer,2004-2021,were obtained from SEER rate sessions using SEER*Stat version 8.4.4.Average percent changes(APC)over time in age-adjusted incidence and mortality rates relative to gender,race/ethnicity,and stage at diagnosis were assessed using Joinpoint’s loglinear regression.Finally,Poisson regression was used to ascertain incidence and mortality rate ratios to ascertain associations between age,gender,race/ethnicity,and staging with incidence and mortality rates.All analyses were further stratified by gender to assess interactions between gender and the other demographic and clinical characteristics.RESULTS Overall,the data reveals significant trends in both the incidence and mortality rates of esophageal cancer,with notable variations across gender,race,and stage at diagnosis.Age-adjusted incidence and mortality rates were higher in males compared to females(incidence:4.1 per 100000 vs 0.9 per 100000,mortality:3.4 per 100000 vs 0.7 per 100000),P<0.001.Furthermore,the APC among males decreased more significantly over time[APC(95%CI):-1.14(-1.52 to-0.78);P<0.001].Both non-Hispanic(NH)Blacks and NH Whites showed significant decreases in cancer incidence,with NH Blacks observing a 3.27%decline and NH Whites a 0.51%decline.Patients with distant staging had a 5%APC increase in mortality rates over time(P=0.003).Additionally,mortality rates increased with age,and all minority groups showed declines in incidence and mortality compared to NH Whites.Cancer diagnosed at a distant stage had a mortality rate 4.16 times higher than in situ cases.CONCLUSION The analysis reveals clear disparities in both the incidence and mortality of esophageal cancer,with males,particularly NH Whites,experiencing significantly higher rates than females.Despite a general decline in incidence rates over time,the upward trend in mortality for certain subgroups warrants further investigation into potential contributing factors such as healthcare access,treatment efficacy,and underlying socio-economic disparities.展开更多
The grating ends bonding fiber Bragg grating(FBG)sensor has been widely used in sensor packages such as substrate type and clamp type for health monitoring of large structures.However,owing to the shear deformation of...The grating ends bonding fiber Bragg grating(FBG)sensor has been widely used in sensor packages such as substrate type and clamp type for health monitoring of large structures.However,owing to the shear deformation of the adhesive layer of FBG,the strain measured by FBG is often different from the strain of actual matrix,which causes strain measurement errors.This investigation aims at improving the measurement accuracy of strain for the grating ends surface-bonded FBG.To fulfill this objective,a strain transfer equation of the grating ends bonding FBG is derived,and a theoretical model of the average strain transfer from the matrix to the optical fiber is developed.Moreover,parameters that influence the average strain transfer rate from the matrix to the optical fiber are analyzed.A selection scheme of bonding parameters by numerical simulation is provided,which is significantly advantageous over that of the grating bonding FBG.The theoretical equation is verified by finite element method(FEM).Compared with the existing model,the proposed model has higher measurement accuracy.Experimental tests are performed to validate the effectiveness of the proposed model on the equalintensity cantilever beam,whose surface is attached to the bare FBG with grating ends bonding and strain gauge by using epoxy glue.The results show that there is a great agreement between the outcome of the bare FBG and that of the strain gauge,and the corrected strain is closer to the true strain.The proposed model provides a theoretical basis for the design of the grating ends surface-bonded FBG strain sensor for health monitoring of large structures.展开更多
Gateways at faces of great mining heights are mostly driven along the roof of coal seams.For gateway height restrictions,a 1-3 m floor coal is retained,leaving a triangular floor coal at the face ends,causing a loss o...Gateways at faces of great mining heights are mostly driven along the roof of coal seams.For gateway height restrictions,a 1-3 m floor coal is retained,leaving a triangular floor coal at the face ends,causing a loss of coal.In order to improve coal recovery rates and to ensure efficiency of equipment at coal mining faces,we investigated suitable retention methods and recovery technology of floor coal at face ends.The upper floor coal can directly be recovered by a shearer with floor dinting.The lower floor coal is recovered by shearer with floor dinting after advanced floor dinting and retaining a step for protecting coal sides in a haulage gateway.Field practice shows that this method can improve the coal recovery rates at fully mechanized working faces with great mining heights.展开更多
Objectives: To obtain very end full-length cDNA ofhepatitis C virus (HCV) 5’ untranslated region(5’UTR) and analyze its primary and secondarystructure.Methods: A patient infected genotype 2a HCV wasidentified by rev...Objectives: To obtain very end full-length cDNA ofhepatitis C virus (HCV) 5’ untranslated region(5’UTR) and analyze its primary and secondarystructure.Methods: A patient infected genotype 2a HCV wasidentified by reverse transcription-nested polymerasechain reaction (RT-PCR) and restriction fragmentlength polymorphism (RFLP). Total RNA isolatedfrom the serum was used as template, and the cDNAof the 5’ untranslated region was amplified using rap-id amplification of cDNA ends (RACE). The frag-ments were recombinated by A-T clone strategy, andthe recombinants were confirmed by RFLP andPCR, and sequenced subsequently. Secondary struc-tures were analysed by RNAdraw.Results: Very end full-length cDNA of genotype 2aHCV 5’ UTR was obtained by RACE. In five clonesobtained, three contained full-length 5’UTR cDNA;A21G, G170A, T222C, T247C, C339T substitutionswere found as compared to HC-J6. Homological re-sults of HCV-1, HC-J6, HC-C2, HC-J8 were 93.6%-94.4%, 92.1%-93%, 98.8%-99.7%, 96.2%-96.5%, respectively; however, the substitutions didnot alter secondary structure. Two of 5 clones weredeletions of 53bp and 135bp at the 5’terminal ofHCV 5’UTR, respectively.Conclusions: RACE can be used to obtain the full-length cDNA of 2a genotype HCV 5’UTR. Genes de-leted at the 5’ terminal of HCV circulate in hepatitisC patients.展开更多
In this work we report that after single-walled carbon nanotubes(SWNTs) are sheared with a pair of titanium scissors,the magnetization becomes larger than that of the corresponding pristine ones. The magnetization inc...In this work we report that after single-walled carbon nanotubes(SWNTs) are sheared with a pair of titanium scissors,the magnetization becomes larger than that of the corresponding pristine ones. The magnetization increases proportionally with the number of SWNTs with sheared ends, suggesting that there exist magnetic moments at the sheared ends of SWNTs.By using the coefficient of this linear relation, the average magnetic moment is estimated to be 41.5 ± 9.8 μB(Bohr magneton) per carbon atom in the edge state at temperature of 300.0 K, suggesting that ultrahigh magnetic fields can be produced. The dangling sigma and pi bonds of the carbon atoms at sheared ends play important roles in determining the unexpectedly high magnetic moments, which may have great potential applications.展开更多
The attractions of cantilevers made of multiwalled carbon nanotubes（MWNTs） and secured on one end are studied in the non-uniform magnetic field of a permanent magnet. Under an optical microscope, the positions and t...The attractions of cantilevers made of multiwalled carbon nanotubes（MWNTs） and secured on one end are studied in the non-uniform magnetic field of a permanent magnet. Under an optical microscope, the positions and the corresponding deflections of the original cantilevers（with iron catalytic nanoparticles at the free end） and corresponding cut-off cantilevers（the free ends consisting of open ends of MWNTs） are studied. Both kinds of CNT cantilevers are found to be attracted by the magnet, and the point of application of force is proven to be at the tip of the cantilever. By measuring and comparing deflections between these two kinds of cantilevers, the magnetic moment at the open ends of the CNTs can be quantified.Due to the unexpectedly high value of the magnetic moment at the open ends of carbon nanotubes, it is called giant magnetic moment, and its possible mechanisms are proposed and discussed.展开更多
AIM:To investigate national trends in distal pancreatectomy(DP) through query of three national patient care databases.METHODS:From the Nationwide Inpatient Sample(NIS,2003-2009),the National Surgical Quality Improvem...AIM:To investigate national trends in distal pancreatectomy(DP) through query of three national patient care databases.METHODS:From the Nationwide Inpatient Sample(NIS,2003-2009),the National Surgical Quality Improvement Project(NSQIP,2005-2010),and the Surveillance Epidemiology and End Results(SEER,2003-2009) databases using appropriate diagnostic and procedural codes we identified all patients with a diagnosis of a benign or malignant lesion of the body and/or tail of the pancreas that had undergone a partial or distal pancreatectomy.Utilization of laparoscopy was defined in NIS by the International Classification of Diseases,Ninth Revision correspondent procedure code;and in NSQIP by the exploratory laparoscopy or unlisted procedure current procedural terminology codes.In SEER,patients were identified by the International Classification of Diseases for Oncology,Third Edition diagnosis codes and the SEER Program Code Manual,third edition procedure codes.We analyzed the databases with respect to trends of inpatient outcome metrics,oncologic outcomes,and hospital volumes in patients with lesions of the neck and body of the pancreas that underwent operative resection.RESULTS:NIS,NSQIP and SEER identified 4242,2681 and 11 082 DP resections,respectively.Overall,laparoscopy was utilized in 15%(NIS) and 27%(NSQIP).No significant increase was seen over the course of the study.Resection was performed for malignancy in 59%(NIS) and 66%(NSQIP).Neither patient Body mass index nor comorbidities were associated with operative approach(P = 0.95 and P = 0.96,respectively).Mortality(3% vs 2%,P = 0.05) and reoperation(4% vs 4%,P = 1.0) was not different between laparoscopy and open groups.Overall complications(10% vs 15%,P < 0.001),hospital costs [44 741 dollars,interquartile range(IQR) 28 347-74 114 dollars vs 49 792 dollars,IQR 13 299-73 463,P = 0.02] and hospital length of stay(7 d,IQR 4-11 d vs 7 d,IQR 6-10,P < 0.001) were less when laparoscopy was utilized.One and two year survival after resection for malignancy were unchanged over the course of the study(ductal adenocarinoma 1-year 63.6% and 2-year 35.1%,P = 0.53;intraductal papillary mucinous neoplasm and nueroendocrine 1-year 90% and 2-year 84%,P = 0.25).The majority of resections were performed in teaching hospitals(77% NIS and 85% NSQIP),but minimally invasive surgery(MIS) was not more likely to be used in teaching hospitals(15% vs 14%,P = 0.26).Hospitals in the top decile for volume were more likely to be teaching hospitals than lower volume deciles(88% vs 43%,P < 0.001),but were no more likely to utilize MIS at resection.Complication rate in teaching and the top decile hospitals was not significantly decreased when compared to non-teaching(15% vs 14%,P = 0.72) and lower volume hospitals(14% vs 15%,P = 0.99).No difference was seen in the median number of lymph nodes and lymph node ratio in N1 disease when compared by year(P = 0.17 and P = 0.96,respectively).CONCLUSION:There appears to be an overall underutilization of laparoscopy for DP.Centralization does not appear to be occurring.Survival and lymph node harvest have not changed.展开更多
The Korea peninsula extends southward from the eastern end of the Asian continent. It is divided just slightly north of the 38th parallel. The peninsula is roughly 1020 km(612 miles) long and 175 km( 105 miles) wide a...The Korea peninsula extends southward from the eastern end of the Asian continent. It is divided just slightly north of the 38th parallel. The peninsula is roughly 1020 km(612 miles) long and 175 km( 105 miles) wide at its narrowest point.展开更多
I HAVE spent the golden years of my life and career in China, having come to Beijing from Cairo as a 22-year-old, That was in 2008 and this is 2016, so you could call it a life-time experience.
The present study aims to analyze the shift in shoreline due to coastal processes and formulate available for best estimate of future shoreline positions based on precedent shorelines. Information on rates and trends ...The present study aims to analyze the shift in shoreline due to coastal processes and formulate available for best estimate of future shoreline positions based on precedent shorelines. Information on rates and trends of shoreline change can be used to improve the understanding of the underlying causes and potential effects of coastal erosion which can support informed coastal management decisions. In this paper, researchers go over the changes in the recent positions of the shoreline of the Balasore coast for the 38 years from 1975 through 2013. The study area includes the Balasore coastal region from Rasalpur to Udaypur together with Chandipur, Choumukh, Chandrabali as well as Bichitrapur. Transects wise shoreline data base were developed for approximately 67 kilometers of shoreline and erosional/accretional scenario has also been analysed by delineating the shoreline from Landsat imageries of 1975, 1980, 1990, 1995, 2000, 2005, 2010 and 2013. A simple Linear Regression Model and End Point Rate (EPR) have been adopted to take out the rate of change of shoreline and its future positions, based on empirical observations at 67 transects along the Balasore coast. It is found that the north eastern part of Balasore coast in the vicinity of Subarnarekha estuary and Chandrabali beach undergo high rates of shore line shift. The shoreline data were integrated for long- (about 17 years) and short-term (about 7 years) shift rates analysis to comprehend the shoreline change and prediction. For the prediction of future shoreline, the model has been validated with the present shoreline position (2013). The rate of shoreline movement calculated from the fixed base line to shoreline position of 1975, 1980, 1990, 1995, 2000, 2005 and 2010 and based on this, the estimated shoreline of 2013 was calculated. The estimated shoreline was compared with the actual shoreline delineated from satellite imagery of 2013. The model error or positional shift at each sample point is observed. The positional error varies from??4.82 m to 212.41 m. It has been found that model prediction error is higher in the left hand side of river Subarnarekha. The overall error for the entire predicted shoreline was found to be 41.88 m by Root Mean Square Error (RMSE). In addition, it was tested by means difference between actual and predicted shoreline positions using “t” test and it has been found that predicted shore line is not significantly different from actual shoreline position at (t132 = 0.278) p < 0.01.展开更多
After the North China grid and the Central China grid get into connection with the UHVAC demonstration, a new phenomenon is discovered according to some simulations. That is, the faults at the remote end of the UHV in...After the North China grid and the Central China grid get into connection with the UHVAC demonstration, a new phenomenon is discovered according to some simulations. That is, the faults at the remote end of the UHV interconnected grid will result in significant power fluctuation and voltage drop on the UHV transmission line and even system splitting. But the faults near the UHV line only have marginal effects. Further, the simulation results also indicate that the short-circuit current of the buses near the UHV line is larger than that of the buses far away from the UHV line. This phenomenon is divergent from the traditional view. In this paper, the detail will be introduced, and the factors influencing the system stability after faults are presented and analyzed. The results indicate that transmission power of the UHV line and of the lines between the remote end and the major grid influence the fluctuation on UHV line. The load model and the grid structure of the remote end also have effect on it. Finally, corresponding control scheme is presented to improve the operation conditions of the UHV interconnected grid and ensure its security and stability.展开更多
Based on the 1951-2007 thunderstorms in Jiangsu,a study is conducted for their climate trends,periodicity,spatiotemporal patterns,and the distributions of the first and last days of the thunderstorms at different guar...Based on the 1951-2007 thunderstorms in Jiangsu,a study is conducted for their climate trends,periodicity,spatiotemporal patterns,and the distributions of the first and last days of the thunderstorms at different guarantee rates (GRs) using climate tendency rate,wavelet analysis,and GR for diagnosis.Results suggest that the inter-annual number of thunderstorm days (TSDs) exhibits a decreasing trend in this province.The trend is displayed mainly in the decreasing TSD number in summer and autumn except in spring,when the variation is not significant in the study period.In this province,the TSD number declines by ～2 days per 10 years.On an inter-annual basis,the pronounced positive departures of the number take place chiefly in the early 1960s,the late 1960s to the early-mid-1970s,the late 1980s,and the late 1990s compared with the negative anomalies dominant in the late 1970s to the mid-1980s,the mid-to-late-1990s,and the late 1990s to 2007.There are vast differences in the initial and ending days at diverse GRs in different areas of the province.At 50% GR,the earliest (last) days occur from mid-March to early April (early to late September) while at 80% GR,the initial (last) days are from late March to early May (early to late October).For the distribution of periods,the periods >8-10 years are relatively stable for the entire province.Based on 1951-2007 period analysis,the region north (south) of the Huaihe River experiences TSDs less (more) than normal days in recent years.展开更多
This paper analyzes the power markets both in northwest sending end and, east receiving ends, points out the favorable and unfavorable conditions for power development In, the northwest area, brings forward,the develo...This paper analyzes the power markets both in northwest sending end and, east receiving ends, points out the favorable and unfavorable conditions for power development In, the northwest area, brings forward,the development planning of power sources and power network constructions, and presents the benefit estimation of sending power from northwest to east.展开更多
Bolting steel angles at the bottom ends of columns provides a rapid and efficient method for repairing damaged structures,while also offering a viable approach to restore their potential bearing capacity.To validate t...Bolting steel angles at the bottom ends of columns provides a rapid and efficient method for repairing damaged structures,while also offering a viable approach to restore their potential bearing capacity.To validate the suitability of specific strengthening strategies,particularly the utilization of bolted steel angles,three reinforced concrete frame specimens were subjected to hysteresis testing.These specimens all featured RC columns strengthened with steel angle ends.Additionally,one control specimen without steel angle ends was included in the testing.The hysteresis effects of bolting steel angles were discussed in terms of typical failure mode,hysteresis and skeleton curves,stiffness degradation and energy dissipation.The experimental results revealed that the three specimens that had bolted steel angles exhibited ductile failure behavior.Through analysis of hysteresis and skeleton curves,it was observed that the frame demonstrated distinct plasticity,maintaining sufficient load-bearing capacity even after yielding and exhibiting superior displacement ductility performance.Considering equivalent viscous damping,the energy dissipation capacity of the RC frame increased linearly with drift and remained largely unaffected by structural damage.Therefore,bolting steel angles at specified cross-sections proved to be a viable technique for structural repair and restoration.展开更多
Clinical guidelines universally recommend active surveillance—monitoring with curative intent—for indolent-grade group(GG)1 prostate cancer(PCa).Moreover,a growing body of literature supports reclassifying GG 1 as“...Clinical guidelines universally recommend active surveillance—monitoring with curative intent—for indolent-grade group(GG)1 prostate cancer(PCa).Moreover,a growing body of literature supports reclassifying GG 1 as“non-cancer.”^([1])However,PCa is often multifocal,and a biopsy may be performed for diagnosis.To assess potential biopsy undersampling,we characterized upgrading and upstaging at radical prostatectomy(RP)among males initially diagnosed with GG1 disease using data from 2 large cohorts:Sur-veillance,Epidemiology,and End Results(SEER)and the National Cancer Database(NCDB).展开更多
In present study,free vibration of cracked beams resting on two-parameter elastic foundation with elastically restrained ends is considered.Euler-Bemoulli beam hypothesis has been applied and translational and rotatio...In present study,free vibration of cracked beams resting on two-parameter elastic foundation with elastically restrained ends is considered.Euler-Bemoulli beam hypothesis has been applied and translational and rotational elastic springs in each end considered as support.The crack is modeled as a mass-less rotational spring which divides beam into two segments.After governing the equations of motion,the differential transform method(DTM)has been served to determine dimensionless frequencies and normalized mode shapes.DTM is a semi-analytical approach based on Taylor expansion series that converts differential equations to recursive algebraic equations.The DTM results for the natural frequencies in special cases are in very good agreement with results reported by well-known references.Also,the DTM procedure yields rapid convergence beside high accuracy without any frequency missing.Comprehensive studies to analyze the effects of crack location,crack severity,parameters of elastic foundation and boundary conditions on dimensionless frequencies as well as effects of elastic boundary conditions on cracked beams mode shapes are carried out and some problems handled for first time in this paper.Since this paper deals with general problem,the derived formulation has capability for analyzing free vibration of cracked beam with every boundary condition.展开更多
Founded in September 2020,the International SparkLink Alliance(iSLA)now has approximately 1,200 members in diverse sectors including terminals,homes,vehicles,manufacturing,transportation,finance and healthcare.The iSL...Founded in September 2020,the International SparkLink Alliance(iSLA)now has approximately 1,200 members in diverse sectors including terminals,homes,vehicles,manufacturing,transportation,finance and healthcare.The iSLA has established a technical standards system for wireless short-range communication covering full-stack standards such as the end-to-end protocol system.展开更多
文摘BACKGROUND Esophageal cancer is a significant global health concern,characterized by high mortality rates and diverse histological types,primarily adenocarcinoma and squamous cell carcinoma.AIM To analyze trends in esophageal cancer using Surveillance,Epidemiology,and End Results(SEER)data,focusing on patient characteristics,stage at diagnosis,treatment modalities,and survival outcomes,to provide insights that may guide clinical practice and public health initiatives.METHODS Age-adjusted incidence and mortality rates for esophageal cancer,2004-2021,were obtained from SEER rate sessions using SEER*Stat version 8.4.4.Average percent changes(APC)over time in age-adjusted incidence and mortality rates relative to gender,race/ethnicity,and stage at diagnosis were assessed using Joinpoint’s loglinear regression.Finally,Poisson regression was used to ascertain incidence and mortality rate ratios to ascertain associations between age,gender,race/ethnicity,and staging with incidence and mortality rates.All analyses were further stratified by gender to assess interactions between gender and the other demographic and clinical characteristics.RESULTS Overall,the data reveals significant trends in both the incidence and mortality rates of esophageal cancer,with notable variations across gender,race,and stage at diagnosis.Age-adjusted incidence and mortality rates were higher in males compared to females(incidence:4.1 per 100000 vs 0.9 per 100000,mortality:3.4 per 100000 vs 0.7 per 100000),P<0.001.Furthermore,the APC among males decreased more significantly over time[APC(95%CI):-1.14(-1.52 to-0.78);P<0.001].Both non-Hispanic(NH)Blacks and NH Whites showed significant decreases in cancer incidence,with NH Blacks observing a 3.27%decline and NH Whites a 0.51%decline.Patients with distant staging had a 5%APC increase in mortality rates over time(P=0.003).Additionally,mortality rates increased with age,and all minority groups showed declines in incidence and mortality compared to NH Whites.Cancer diagnosed at a distant stage had a mortality rate 4.16 times higher than in situ cases.CONCLUSION The analysis reveals clear disparities in both the incidence and mortality of esophageal cancer,with males,particularly NH Whites,experiencing significantly higher rates than females.Despite a general decline in incidence rates over time,the upward trend in mortality for certain subgroups warrants further investigation into potential contributing factors such as healthcare access,treatment efficacy,and underlying socio-economic disparities.
文摘The grating ends bonding fiber Bragg grating(FBG)sensor has been widely used in sensor packages such as substrate type and clamp type for health monitoring of large structures.However,owing to the shear deformation of the adhesive layer of FBG,the strain measured by FBG is often different from the strain of actual matrix,which causes strain measurement errors.This investigation aims at improving the measurement accuracy of strain for the grating ends surface-bonded FBG.To fulfill this objective,a strain transfer equation of the grating ends bonding FBG is derived,and a theoretical model of the average strain transfer from the matrix to the optical fiber is developed.Moreover,parameters that influence the average strain transfer rate from the matrix to the optical fiber are analyzed.A selection scheme of bonding parameters by numerical simulation is provided,which is significantly advantageous over that of the grating bonding FBG.The theoretical equation is verified by finite element method(FEM).Compared with the existing model,the proposed model has higher measurement accuracy.Experimental tests are performed to validate the effectiveness of the proposed model on the equalintensity cantilever beam,whose surface is attached to the bare FBG with grating ends bonding and strain gauge by using epoxy glue.The results show that there is a great agreement between the outcome of the bare FBG and that of the strain gauge,and the corrected strain is closer to the true strain.The proposed model provides a theoretical basis for the design of the grating ends surface-bonded FBG strain sensor for health monitoring of large structures.
基金the Independent Research of the State Key Laboratory of Coal Resources and Mine Safety(No. SKLCRSM09X02)the Open Research Fund of the State Key Laboratory of Coal Resources and Mine Safety(No.08KF12)the Graduate Students of Jiangsu Province Innovation Program Funded Projects(No.CX09B_120Z) for their financial support
文摘Gateways at faces of great mining heights are mostly driven along the roof of coal seams.For gateway height restrictions,a 1-3 m floor coal is retained,leaving a triangular floor coal at the face ends,causing a loss of coal.In order to improve coal recovery rates and to ensure efficiency of equipment at coal mining faces,we investigated suitable retention methods and recovery technology of floor coal at face ends.The upper floor coal can directly be recovered by a shearer with floor dinting.The lower floor coal is recovered by shearer with floor dinting after advanced floor dinting and retaining a step for protecting coal sides in a haulage gateway.Field practice shows that this method can improve the coal recovery rates at fully mechanized working faces with great mining heights.
基金This work was supported by two grants from National Science Foundation of China (No: 39770684, 30170844).
文摘Objectives: To obtain very end full-length cDNA ofhepatitis C virus (HCV) 5’ untranslated region(5’UTR) and analyze its primary and secondarystructure.Methods: A patient infected genotype 2a HCV wasidentified by reverse transcription-nested polymerasechain reaction (RT-PCR) and restriction fragmentlength polymorphism (RFLP). Total RNA isolatedfrom the serum was used as template, and the cDNAof the 5’ untranslated region was amplified using rap-id amplification of cDNA ends (RACE). The frag-ments were recombinated by A-T clone strategy, andthe recombinants were confirmed by RFLP andPCR, and sequenced subsequently. Secondary struc-tures were analysed by RNAdraw.Results: Very end full-length cDNA of genotype 2aHCV 5’ UTR was obtained by RACE. In five clonesobtained, three contained full-length 5’UTR cDNA;A21G, G170A, T222C, T247C, C339T substitutionswere found as compared to HC-J6. Homological re-sults of HCV-1, HC-J6, HC-C2, HC-J8 were 93.6%-94.4%, 92.1%-93%, 98.8%-99.7%, 96.2%-96.5%, respectively; however, the substitutions didnot alter secondary structure. Two of 5 clones weredeletions of 53bp and 135bp at the 5’terminal ofHCV 5’UTR, respectively.Conclusions: RACE can be used to obtain the full-length cDNA of 2a genotype HCV 5’UTR. Genes de-leted at the 5’ terminal of HCV circulate in hepatitisC patients.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2018YFA0208403 and 2016YFA0200403)the National Natural Science Foundation of China(Grant Nos.51472057,11874129,91323304,and 11674387)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA09040101)the Baotou Rare Earth Research and Development Centre,Chinese Academy of Sciences(Grant No.GZR 2018001)
文摘In this work we report that after single-walled carbon nanotubes(SWNTs) are sheared with a pair of titanium scissors,the magnetization becomes larger than that of the corresponding pristine ones. The magnetization increases proportionally with the number of SWNTs with sheared ends, suggesting that there exist magnetic moments at the sheared ends of SWNTs.By using the coefficient of this linear relation, the average magnetic moment is estimated to be 41.5 ± 9.8 μB(Bohr magneton) per carbon atom in the edge state at temperature of 300.0 K, suggesting that ultrahigh magnetic fields can be produced. The dangling sigma and pi bonds of the carbon atoms at sheared ends play important roles in determining the unexpectedly high magnetic moments, which may have great potential applications.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10774032 and 51472057)the Instrument Developing Project of the Chinese Academy of Sciences(Grant No.Y2010031)
文摘The attractions of cantilevers made of multiwalled carbon nanotubes（MWNTs） and secured on one end are studied in the non-uniform magnetic field of a permanent magnet. Under an optical microscope, the positions and the corresponding deflections of the original cantilevers（with iron catalytic nanoparticles at the free end） and corresponding cut-off cantilevers（the free ends consisting of open ends of MWNTs） are studied. Both kinds of CNT cantilevers are found to be attracted by the magnet, and the point of application of force is proven to be at the tip of the cantilever. By measuring and comparing deflections between these two kinds of cantilevers, the magnetic moment at the open ends of the CNTs can be quantified.Due to the unexpectedly high value of the magnetic moment at the open ends of carbon nanotubes, it is called giant magnetic moment, and its possible mechanisms are proposed and discussed.
文摘AIM:To investigate national trends in distal pancreatectomy(DP) through query of three national patient care databases.METHODS:From the Nationwide Inpatient Sample(NIS,2003-2009),the National Surgical Quality Improvement Project(NSQIP,2005-2010),and the Surveillance Epidemiology and End Results(SEER,2003-2009) databases using appropriate diagnostic and procedural codes we identified all patients with a diagnosis of a benign or malignant lesion of the body and/or tail of the pancreas that had undergone a partial or distal pancreatectomy.Utilization of laparoscopy was defined in NIS by the International Classification of Diseases,Ninth Revision correspondent procedure code;and in NSQIP by the exploratory laparoscopy or unlisted procedure current procedural terminology codes.In SEER,patients were identified by the International Classification of Diseases for Oncology,Third Edition diagnosis codes and the SEER Program Code Manual,third edition procedure codes.We analyzed the databases with respect to trends of inpatient outcome metrics,oncologic outcomes,and hospital volumes in patients with lesions of the neck and body of the pancreas that underwent operative resection.RESULTS:NIS,NSQIP and SEER identified 4242,2681 and 11 082 DP resections,respectively.Overall,laparoscopy was utilized in 15%(NIS) and 27%(NSQIP).No significant increase was seen over the course of the study.Resection was performed for malignancy in 59%(NIS) and 66%(NSQIP).Neither patient Body mass index nor comorbidities were associated with operative approach(P = 0.95 and P = 0.96,respectively).Mortality(3% vs 2%,P = 0.05) and reoperation(4% vs 4%,P = 1.0) was not different between laparoscopy and open groups.Overall complications(10% vs 15%,P < 0.001),hospital costs [44 741 dollars,interquartile range(IQR) 28 347-74 114 dollars vs 49 792 dollars,IQR 13 299-73 463,P = 0.02] and hospital length of stay(7 d,IQR 4-11 d vs 7 d,IQR 6-10,P < 0.001) were less when laparoscopy was utilized.One and two year survival after resection for malignancy were unchanged over the course of the study(ductal adenocarinoma 1-year 63.6% and 2-year 35.1%,P = 0.53;intraductal papillary mucinous neoplasm and nueroendocrine 1-year 90% and 2-year 84%,P = 0.25).The majority of resections were performed in teaching hospitals(77% NIS and 85% NSQIP),but minimally invasive surgery(MIS) was not more likely to be used in teaching hospitals(15% vs 14%,P = 0.26).Hospitals in the top decile for volume were more likely to be teaching hospitals than lower volume deciles(88% vs 43%,P < 0.001),but were no more likely to utilize MIS at resection.Complication rate in teaching and the top decile hospitals was not significantly decreased when compared to non-teaching(15% vs 14%,P = 0.72) and lower volume hospitals(14% vs 15%,P = 0.99).No difference was seen in the median number of lymph nodes and lymph node ratio in N1 disease when compared by year(P = 0.17 and P = 0.96,respectively).CONCLUSION:There appears to be an overall underutilization of laparoscopy for DP.Centralization does not appear to be occurring.Survival and lymph node harvest have not changed.
文摘The Korea peninsula extends southward from the eastern end of the Asian continent. It is divided just slightly north of the 38th parallel. The peninsula is roughly 1020 km(612 miles) long and 175 km( 105 miles) wide at its narrowest point.
文摘I HAVE spent the golden years of my life and career in China, having come to Beijing from Cairo as a 22-year-old, That was in 2008 and this is 2016, so you could call it a life-time experience.
文摘The present study aims to analyze the shift in shoreline due to coastal processes and formulate available for best estimate of future shoreline positions based on precedent shorelines. Information on rates and trends of shoreline change can be used to improve the understanding of the underlying causes and potential effects of coastal erosion which can support informed coastal management decisions. In this paper, researchers go over the changes in the recent positions of the shoreline of the Balasore coast for the 38 years from 1975 through 2013. The study area includes the Balasore coastal region from Rasalpur to Udaypur together with Chandipur, Choumukh, Chandrabali as well as Bichitrapur. Transects wise shoreline data base were developed for approximately 67 kilometers of shoreline and erosional/accretional scenario has also been analysed by delineating the shoreline from Landsat imageries of 1975, 1980, 1990, 1995, 2000, 2005, 2010 and 2013. A simple Linear Regression Model and End Point Rate (EPR) have been adopted to take out the rate of change of shoreline and its future positions, based on empirical observations at 67 transects along the Balasore coast. It is found that the north eastern part of Balasore coast in the vicinity of Subarnarekha estuary and Chandrabali beach undergo high rates of shore line shift. The shoreline data were integrated for long- (about 17 years) and short-term (about 7 years) shift rates analysis to comprehend the shoreline change and prediction. For the prediction of future shoreline, the model has been validated with the present shoreline position (2013). The rate of shoreline movement calculated from the fixed base line to shoreline position of 1975, 1980, 1990, 1995, 2000, 2005 and 2010 and based on this, the estimated shoreline of 2013 was calculated. The estimated shoreline was compared with the actual shoreline delineated from satellite imagery of 2013. The model error or positional shift at each sample point is observed. The positional error varies from??4.82 m to 212.41 m. It has been found that model prediction error is higher in the left hand side of river Subarnarekha. The overall error for the entire predicted shoreline was found to be 41.88 m by Root Mean Square Error (RMSE). In addition, it was tested by means difference between actual and predicted shoreline positions using “t” test and it has been found that predicted shore line is not significantly different from actual shoreline position at (t132 = 0.278) p < 0.01.
文摘After the North China grid and the Central China grid get into connection with the UHVAC demonstration, a new phenomenon is discovered according to some simulations. That is, the faults at the remote end of the UHV interconnected grid will result in significant power fluctuation and voltage drop on the UHV transmission line and even system splitting. But the faults near the UHV line only have marginal effects. Further, the simulation results also indicate that the short-circuit current of the buses near the UHV line is larger than that of the buses far away from the UHV line. This phenomenon is divergent from the traditional view. In this paper, the detail will be introduced, and the factors influencing the system stability after faults are presented and analyzed. The results indicate that transmission power of the UHV line and of the lines between the remote end and the major grid influence the fluctuation on UHV line. The load model and the grid structure of the remote end also have effect on it. Finally, corresponding control scheme is presented to improve the operation conditions of the UHV interconnected grid and ensure its security and stability.
基金Social Development Program of Jiangsu Science and Technology (BS2007088)
文摘Based on the 1951-2007 thunderstorms in Jiangsu,a study is conducted for their climate trends,periodicity,spatiotemporal patterns,and the distributions of the first and last days of the thunderstorms at different guarantee rates (GRs) using climate tendency rate,wavelet analysis,and GR for diagnosis.Results suggest that the inter-annual number of thunderstorm days (TSDs) exhibits a decreasing trend in this province.The trend is displayed mainly in the decreasing TSD number in summer and autumn except in spring,when the variation is not significant in the study period.In this province,the TSD number declines by ～2 days per 10 years.On an inter-annual basis,the pronounced positive departures of the number take place chiefly in the early 1960s,the late 1960s to the early-mid-1970s,the late 1980s,and the late 1990s compared with the negative anomalies dominant in the late 1970s to the mid-1980s,the mid-to-late-1990s,and the late 1990s to 2007.There are vast differences in the initial and ending days at diverse GRs in different areas of the province.At 50% GR,the earliest (last) days occur from mid-March to early April (early to late September) while at 80% GR,the initial (last) days are from late March to early May (early to late October).For the distribution of periods,the periods >8-10 years are relatively stable for the entire province.Based on 1951-2007 period analysis,the region north (south) of the Huaihe River experiences TSDs less (more) than normal days in recent years.
文摘This paper analyzes the power markets both in northwest sending end and, east receiving ends, points out the favorable and unfavorable conditions for power development In, the northwest area, brings forward,the development planning of power sources and power network constructions, and presents the benefit estimation of sending power from northwest to east.
基金National Key R&D Program of China under Grant No.2023YFC3805100Technologies R&D Project of China Construction First Group Corporation Limited under Grant No.PT-2022-09National Natural Science Foundation of China under Grant No.52178126。
文摘Bolting steel angles at the bottom ends of columns provides a rapid and efficient method for repairing damaged structures,while also offering a viable approach to restore their potential bearing capacity.To validate the suitability of specific strengthening strategies,particularly the utilization of bolted steel angles,three reinforced concrete frame specimens were subjected to hysteresis testing.These specimens all featured RC columns strengthened with steel angle ends.Additionally,one control specimen without steel angle ends was included in the testing.The hysteresis effects of bolting steel angles were discussed in terms of typical failure mode,hysteresis and skeleton curves,stiffness degradation and energy dissipation.The experimental results revealed that the three specimens that had bolted steel angles exhibited ductile failure behavior.Through analysis of hysteresis and skeleton curves,it was observed that the frame demonstrated distinct plasticity,maintaining sufficient load-bearing capacity even after yielding and exhibiting superior displacement ductility performance.Considering equivalent viscous damping,the energy dissipation capacity of the RC frame increased linearly with drift and remained largely unaffected by structural damage.Therefore,bolting steel angles at specified cross-sections proved to be a viable technique for structural repair and restoration.
文摘Clinical guidelines universally recommend active surveillance—monitoring with curative intent—for indolent-grade group(GG)1 prostate cancer(PCa).Moreover,a growing body of literature supports reclassifying GG 1 as“non-cancer.”^([1])However,PCa is often multifocal,and a biopsy may be performed for diagnosis.To assess potential biopsy undersampling,we characterized upgrading and upstaging at radical prostatectomy(RP)among males initially diagnosed with GG1 disease using data from 2 large cohorts:Sur-veillance,Epidemiology,and End Results(SEER)and the National Cancer Database(NCDB).
文摘In present study,free vibration of cracked beams resting on two-parameter elastic foundation with elastically restrained ends is considered.Euler-Bemoulli beam hypothesis has been applied and translational and rotational elastic springs in each end considered as support.The crack is modeled as a mass-less rotational spring which divides beam into two segments.After governing the equations of motion,the differential transform method(DTM)has been served to determine dimensionless frequencies and normalized mode shapes.DTM is a semi-analytical approach based on Taylor expansion series that converts differential equations to recursive algebraic equations.The DTM results for the natural frequencies in special cases are in very good agreement with results reported by well-known references.Also,the DTM procedure yields rapid convergence beside high accuracy without any frequency missing.Comprehensive studies to analyze the effects of crack location,crack severity,parameters of elastic foundation and boundary conditions on dimensionless frequencies as well as effects of elastic boundary conditions on cracked beams mode shapes are carried out and some problems handled for first time in this paper.Since this paper deals with general problem,the derived formulation has capability for analyzing free vibration of cracked beam with every boundary condition.
文摘Founded in September 2020,the International SparkLink Alliance(iSLA)now has approximately 1,200 members in diverse sectors including terminals,homes,vehicles,manufacturing,transportation,finance and healthcare.The iSLA has established a technical standards system for wireless short-range communication covering full-stack standards such as the end-to-end protocol system.
