Acoustic waves enter a rock formation from a borehole and are reflected or scattered upon encountering a geologic structure.Consequently,we obtain the structure location represented by the azimuth and distance from th...Acoustic waves enter a rock formation from a borehole and are reflected or scattered upon encountering a geologic structure.Consequently,we obtain the structure location represented by the azimuth and distance from the borehole using the acoustic reflection or scattering.Downhole acoustic measurements with the azimuthal resolution are realized using an azimuthal acoustic receiver sonde composed of several arcuate phased array receivers.Eight sensors distributed evenly across the arcuate phased array receiver can record acoustic waves independently;this allows us to adopt the beamforming method.We use a supporting logging tool to conduct the downhole test in two adjacent fluid-filled boreholes,for validating the evaluation of the geologic structure using scattered P-waves.The test results show the multi-azimuth images of the target borehole and the azimuthal variation in scattering amplitudes.Thus,we obtain the precise location of the target borehole.Furthermore,the measured values of the target borehole are consistent with the actual values,indicating that we can accurately evaluate a near-borehole geologic structure with scattered P-waves.展开更多
Better well logging techniques for geologic investigations are urgently needed to identify and evaluate complex reservoirs.We describe a new type of 3D transmitter station with corresponding circuits and bodies.They c...Better well logging techniques for geologic investigations are urgently needed to identify and evaluate complex reservoirs.We describe a new type of 3D transmitter station with corresponding circuits and bodies.They can be used in a promising new technique of acoustic reflection well logging,that features better azimuthal detection capabilities,as well as better investigation depth.The transmitter stations consist of three-level subarrays that can radiate acoustic energy in any required azimuth of 3D space by circularly exciting various combinations at different levels.We tested the 3D acoustic transmitter stations and obtained laboratory directivity measurements with the3 D acoustic transmitter stations for the first time.The results show that the 3-d B beam width in the horizontal plane ranges from 59° to 67° as a result of phase-delayed excitation.The main beam is steered in the vertical plane at a deflection angle that ranges from 0° to 16° when the delay time of the excitation pulse between each pair of adjacent arc arrays is gradually adjusted.The 3-d B beam width is equal to 11°,whereas the deflection angle in the vertical plane is equal to 14°.Each of the four third-level subarrays in the same circumferential direction display consistent horizontal and vertical directivities,thus satisfying the requirements of azimuthal acoustic reflection logging.展开更多
Background:Heterotopic ossification(HO)is a known complication of hip arthroscopy.We investigated incidence of HO after hip arthroscopy and determined whether revision for HO improved outcome.Methods:A retrospective s...Background:Heterotopic ossification(HO)is a known complication of hip arthroscopy.We investigated incidence of HO after hip arthroscopy and determined whether revision for HO improved outcome.Methods:A retrospective study was conducted on 242 patients(140 men and 102 women,mean age:36.2±9.5 years)who underwent hip arthroscopy for femoroacetabular impingement(FAI)between January 2016 and January 2018.The average followup period was 22.88±11.74 months(range:11-34 months).Thirteen(5.37%)cases of HO(six men and seven women,five left hips and eight right hips;mean age:37.5±4.7 years)were observed.Among them,four cases with HO with obvious pain symptoms and persistent non-remission underwent revision surgery to remove HO.Monthly follow-up was conducted.Visual analog scale(VAS),modified Harris Hip Score(mHHS),and non-Arthritis Hip Score(NAHS)were evaluated and compared between HO and non-HO patients.Independent sample t test,Mann-Whitney U test and the Chi-square test were used for inter-group comparisons.HO degree was evaluated using Brooker classification.Symptoms and function were evaluated before and after revision.Results:A total of 242 patients were involved in this study.Thirteen cases(5.4%)had imaging evidence of HO.Nine(9/13)were classified as Brooker stageⅠ,three(3/13)Brooker stageⅡ,and one(1/13)Brooker stageⅢ.HO was detected by ultrasonography as early as 3 weeks after operation.After primary surgery,the mHHS of the HO group and non-HO group increased by 13.00(8.50,25.50)and 24.00(14.00,34.50)points(Z=-1.80,P=0.08),NAHS increased by 18.00(9.50,31.50)and 26.00(13.50,36.00)points(Z=-1.34,P=0.18),and VAS decreased by 3.00(2.00,4.00)and 4.00(3.00,4.50)points(Z=-1.55,P=0.12).Average follow-up time after revision was 9.00±2.94 months;mHHS increased by 34.75 points t=-55.23,P<0.01)and NAHS by 28.75 points t=-6.03,P<0.01),and VAS decreased by 4 points t=9.80,P<0.01).HO and non-HO patients were similar for demographic and surgical data,and clinical and functional scores.Conclusion:HO incidence after arthroscopic treatment of FAI is similar to that found in previous studies.Most HO have no effect on clinical symptoms.Patients who undergo revision HO resection show improvement in pain and joint function.展开更多
Background： Amyotrophic lateral sclerosis （ALS） is a fatal neurodegenerative disease that primarily affects motor neurons and has no effective treatment. Recently, Iida et al. identified a single-nucleotide polymor...Background： Amyotrophic lateral sclerosis （ALS） is a fatal neurodegenerative disease that primarily affects motor neurons and has no effective treatment. Recently, Iida et al. identified a single-nucleotide polymorphism （SNP） rs2275294 in the ZNF512B gene that is significantly associated with susceptibility to ALS in the Japanese population. Here, we performed a case-control study examining the possible association of rs2275294 with risk of sporadic ALS （SALS） in a large Chinese cohort. Methods： To assess this association, we performed a replication study in 953 SALS patients and 1039 age- and gender-matched healthy control subjects, who were recruited from Peking University Third Hospital and the First Affiliated Hospital of Anhui Medical University from January 2004 to December 2013 throughout China. We genotyped the rs2275294 SNP using polymerase chain reaction and direct sequencing. Results： The allele frequency of rs2275294 in ZNF512B was different between Japanese and Chinese. The association in Chinese between ALS patients and controls did not reach statistical significance （P = 0.54; odds ratio = 0.94; 95% confidence interval = 0.76-1.15）. Conclusions： The SNP rs2275294 in ZNF512B is not considered to be associated with ALS susceptibility in the Chinese population. Our study highlights genetic heterogeneity in ALS susceptibility in different population. Given our negative results, further replication study involving larger and more homogeneous samples in different ethnicities should be performed in the future.展开更多
基金supported by the National Natural Science Foundation of China(41874210 and 11734017)the National Science and Technology Major Project(2017ZX05019001 and 2017ZX05019006)+1 种基金the Petro China Innovation Foundation(2016D-5007-0303)the Science Foundation of China University of Petroleum,Beijing(2462016YJRC020)。
文摘Acoustic waves enter a rock formation from a borehole and are reflected or scattered upon encountering a geologic structure.Consequently,we obtain the structure location represented by the azimuth and distance from the borehole using the acoustic reflection or scattering.Downhole acoustic measurements with the azimuthal resolution are realized using an azimuthal acoustic receiver sonde composed of several arcuate phased array receivers.Eight sensors distributed evenly across the arcuate phased array receiver can record acoustic waves independently;this allows us to adopt the beamforming method.We use a supporting logging tool to conduct the downhole test in two adjacent fluid-filled boreholes,for validating the evaluation of the geologic structure using scattered P-waves.The test results show the multi-azimuth images of the target borehole and the azimuthal variation in scattering amplitudes.Thus,we obtain the precise location of the target borehole.Furthermore,the measured values of the target borehole are consistent with the actual values,indicating that we can accurately evaluate a near-borehole geologic structure with scattered P-waves.
基金supported by the National Natural Science Foundation of China (Grant Nos.11204380,11374371,61102102,11134011)National Science and Technology Major Project (Grant No.2011ZX05020-009)+2 种基金China National Petroleum Corporation (Grant Nos.2014B-4011,2014D-4105,2014A3912)Petro China Innovation Foundation (2014D-5006-0307)China Scholarship Council (No.201306445018)
文摘Better well logging techniques for geologic investigations are urgently needed to identify and evaluate complex reservoirs.We describe a new type of 3D transmitter station with corresponding circuits and bodies.They can be used in a promising new technique of acoustic reflection well logging,that features better azimuthal detection capabilities,as well as better investigation depth.The transmitter stations consist of three-level subarrays that can radiate acoustic energy in any required azimuth of 3D space by circularly exciting various combinations at different levels.We tested the 3D acoustic transmitter stations and obtained laboratory directivity measurements with the3 D acoustic transmitter stations for the first time.The results show that the 3-d B beam width in the horizontal plane ranges from 59° to 67° as a result of phase-delayed excitation.The main beam is steered in the vertical plane at a deflection angle that ranges from 0° to 16° when the delay time of the excitation pulse between each pair of adjacent arc arrays is gradually adjusted.The 3-d B beam width is equal to 11°,whereas the deflection angle in the vertical plane is equal to 14°.Each of the four third-level subarrays in the same circumferential direction display consistent horizontal and vertical directivities,thus satisfying the requirements of azimuthal acoustic reflection logging.
基金grants from the Beijing Natural Science Foundation(No.7162201)National Natural Science Foundation of China(No.81672182,No.81871761,No.7192221)Beijing New-star Plan of Science and Technology(No.xxjc201711).
文摘Background:Heterotopic ossification(HO)is a known complication of hip arthroscopy.We investigated incidence of HO after hip arthroscopy and determined whether revision for HO improved outcome.Methods:A retrospective study was conducted on 242 patients(140 men and 102 women,mean age:36.2±9.5 years)who underwent hip arthroscopy for femoroacetabular impingement(FAI)between January 2016 and January 2018.The average followup period was 22.88±11.74 months(range:11-34 months).Thirteen(5.37%)cases of HO(six men and seven women,five left hips and eight right hips;mean age:37.5±4.7 years)were observed.Among them,four cases with HO with obvious pain symptoms and persistent non-remission underwent revision surgery to remove HO.Monthly follow-up was conducted.Visual analog scale(VAS),modified Harris Hip Score(mHHS),and non-Arthritis Hip Score(NAHS)were evaluated and compared between HO and non-HO patients.Independent sample t test,Mann-Whitney U test and the Chi-square test were used for inter-group comparisons.HO degree was evaluated using Brooker classification.Symptoms and function were evaluated before and after revision.Results:A total of 242 patients were involved in this study.Thirteen cases(5.4%)had imaging evidence of HO.Nine(9/13)were classified as Brooker stageⅠ,three(3/13)Brooker stageⅡ,and one(1/13)Brooker stageⅢ.HO was detected by ultrasonography as early as 3 weeks after operation.After primary surgery,the mHHS of the HO group and non-HO group increased by 13.00(8.50,25.50)and 24.00(14.00,34.50)points(Z=-1.80,P=0.08),NAHS increased by 18.00(9.50,31.50)and 26.00(13.50,36.00)points(Z=-1.34,P=0.18),and VAS decreased by 3.00(2.00,4.00)and 4.00(3.00,4.50)points(Z=-1.55,P=0.12).Average follow-up time after revision was 9.00±2.94 months;mHHS increased by 34.75 points t=-55.23,P<0.01)and NAHS by 28.75 points t=-6.03,P<0.01),and VAS decreased by 4 points t=9.80,P<0.01).HO and non-HO patients were similar for demographic and surgical data,and clinical and functional scores.Conclusion:HO incidence after arthroscopic treatment of FAI is similar to that found in previous studies.Most HO have no effect on clinical symptoms.Patients who undergo revision HO resection show improvement in pain and joint function.
基金The research was supported by grants from the National Natural Science Foundation of China
文摘Background： Amyotrophic lateral sclerosis （ALS） is a fatal neurodegenerative disease that primarily affects motor neurons and has no effective treatment. Recently, Iida et al. identified a single-nucleotide polymorphism （SNP） rs2275294 in the ZNF512B gene that is significantly associated with susceptibility to ALS in the Japanese population. Here, we performed a case-control study examining the possible association of rs2275294 with risk of sporadic ALS （SALS） in a large Chinese cohort. Methods： To assess this association, we performed a replication study in 953 SALS patients and 1039 age- and gender-matched healthy control subjects, who were recruited from Peking University Third Hospital and the First Affiliated Hospital of Anhui Medical University from January 2004 to December 2013 throughout China. We genotyped the rs2275294 SNP using polymerase chain reaction and direct sequencing. Results： The allele frequency of rs2275294 in ZNF512B was different between Japanese and Chinese. The association in Chinese between ALS patients and controls did not reach statistical significance （P = 0.54; odds ratio = 0.94; 95% confidence interval = 0.76-1.15）. Conclusions： The SNP rs2275294 in ZNF512B is not considered to be associated with ALS susceptibility in the Chinese population. Our study highlights genetic heterogeneity in ALS susceptibility in different population. Given our negative results, further replication study involving larger and more homogeneous samples in different ethnicities should be performed in the future.
