We examine Africa's vaccine manufacturing potential,spurred by the coronavirus disease 2019(COVID-19)pan-demic,while critically analyzing vaccine price inequities and procurement strategies during the pandemic,wit...We examine Africa's vaccine manufacturing potential,spurred by the coronavirus disease 2019(COVID-19)pan-demic,while critically analyzing vaccine price inequities and procurement strategies during the pandemic,with anticipation of future outbreaks.Although Africa consumes approximately 25%of the global vaccine supply,over 99%of these vaccines are produced outside the continent,primarily due to insufficient local investment.Vaccine procurement strategies have relied heavily on pooled procurement mechanisms and tiered-pricing mod-els,predominantly controlled by external organizations.Significant disparities in vaccine pricing have resulted in vaccine price inequities,with evidence suggesting price discrimination,where different prices are charged for the same vaccine across countries and regions.While vaccine prices are only one component of vaccination cam-paign costs,the inequitable pricing of vaccines poses serious challenges to fair access,especially in low-income countries.Given the inevitability of future pandemics and other outbreaks,the central question remains:Does Africa possess the capacity to strengthen its vaccine production infrastructure and reduce dependency on ex-ternal suppliers?Our review reveals that,with robust political commitment,enhanced investment in Research and Development,and leveraging the heterogeneous nature of the regional bloc,Africa has made strides toward establishing vaccine manufacturing hubs with the potential for substantial capacity expansion.Furthermore,we argue for a regional campaign based on the principles of the fair priority model as an ethical framework for vaccine procurement,which prioritizes need and ensures equitable distribution,thereby complementing existing pooled procurement arrangements in times of future pandemics.This paper concludes with two key recommen-dations based on lessons learned from the COvID-19 crisis and future preparedness.First,Africa must push for a transparent and equitable tiered-pricing structure to ensure affordability for all Second,intentional and sustained investment in R&D is critical to addressing systemic inequities in vaccine supply,not only for cOVID-19 but for future outbreaks and routine immunization programs.展开更多
The P24 antigen test, HIV RNA PCR test, HIV isolation/culture and fourth-generation HIV uniform Ag/Ab assay are being utilized in diagnosing acute HIV infection in different labs. Many factors limit the use of screeni...The P24 antigen test, HIV RNA PCR test, HIV isolation/culture and fourth-generation HIV uniform Ag/Ab assay are being utilized in diagnosing acute HIV infection in different labs. Many factors limit the use of screening for acute HIV in high-risk populations, in blood donors and during voluntary HIV testing, including, cost, technique, sensitivity and specificity. In this review we explore a new NAAT method which involves HIV RNA RT-PCR on pooled samples. This technique is able to screen for acute infections in a large testing volume and may be used as a screening method in high-risk populations and blood donors.展开更多
Often in longitudinal studies, some subjects complete their follow-up visits, but others miss their visits due to various reasons. For those who miss follow-up visits, some of them might learn that the event of intere...Often in longitudinal studies, some subjects complete their follow-up visits, but others miss their visits due to various reasons. For those who miss follow-up visits, some of them might learn that the event of interest has already happened when they come back. In this case, not only are their event times interval-censored, but also their time-dependent measurements are incomplete. This problem was motivated by a national longitudinal survey of youth data. Maximum likelihood estimation (MLE) method based on expectation-maximization (EM) algorithm is used for parameter estimation. Then missing information principle is applied to estimate the variance-covariance matrix of the MLEs. Simulation studies demonstrate that the proposed method works well in terms of bias, standard error, and power for samples of moderate size. The national longitudinal survey of youth 1997 (NLSY97) data is analyzed for illustration.展开更多
Purpose: To assess the efficacy and safety of Olaparib, a PARP inhibitor on progression-free survival (PFS), objective response rate (ORR) and overall survival (OS) in patients with breast and ovarian cancer. Methods:...Purpose: To assess the efficacy and safety of Olaparib, a PARP inhibitor on progression-free survival (PFS), objective response rate (ORR) and overall survival (OS) in patients with breast and ovarian cancer. Methods: Research data from clinical trials through PubMed, Science Citation Index, Elsevier Science Direct and Cochrane Library of all published studies exploring the PFS, ORR or OS of Olaparib for maintenance monotherapy on survival in breast and ovarian cancer were analysed. Pooled estimates of the ORR, weighted medians of PFS and OS from all Olaparib were calculated. Assessment of quality and level of evidence was assigned by Cochrane guidelines and guidelines of Oxford Centre for Evidence-Based Medicine. Results: Data of 893 patients (731 olaparib;162 control) from 6 trials, 2 randomised controlled trials and 4 non-randomised trials, were included. The overall median weighted PFS and OS in patients treated with Olaparib were 5.9 and 19.1 months, respectively. The pooled ORR was 25%. Olaparib showed a greater effect on PFS in patients with both wild-type BRCA and BRCA mutant gene. The most common toxicity were nausea and vomiting. Conclusions: Olaparib as maintenance monotherapy for breast and ovarian cancer is associated with promising outcomes including increased response rate and improved PFS. Its potential in clinical application is needed for further investigation in phase III trials.展开更多
Background: Childhood tuberculosis accounts for about 10% of estimated TB cases in the world. Despite advances in diagnostics, childhood TB remains a challenge. We evaluated pooling method and testing with GeneXpert M...Background: Childhood tuberculosis accounts for about 10% of estimated TB cases in the world. Despite advances in diagnostics, childhood TB remains a challenge. We evaluated pooling method and testing with GeneXpert MTB/RIF in southern Ethiopia. Methods: This is a cross-sectional study in presumptive TB children st, 2nd and pooled samples. Results: Of 340 presumptive TB cases enrolled, 96 and 244 children submitted gastric aspirate and sputum samples respectively. Of 1020 samples collected (282 gastric aspirate and 738 sputum samples), 38 (3.7%) were positive by Xpert (10 (3.5%) from gastric aspirate and 28 (3.8%) from sputum sample). Similarly, 8 (1.2%) of sputum samples were positive by ZN but none from gastric aspirate. Of 244 children who submitted sputum samples, 3 (1.2%) were bacteriologically positive compared to 12 (4.9%) by Xpert. Of 96 children who submitted gastric aspirate samples, none were positive by ZN while 5 (5.2%) were positive by Xpert. Of bacteriologically confirmed TB cases 0.9% was by ZN and 4.7% by Xpert, an increase of 3.8%. Pooled testing increased positivity by 0.3% for ZN and 1.5% by Xpert compared to the 1st sample. Conclusions: Xpert MTB/RIF testing increases yield compared to ZN testing for gastric aspirate samples. The same-day approach and pooling samples improves efficient use of cartridge, reduce the number of visits for seeking diagnosis and save resources.展开更多
Four enzyme immunoassay (EIA) test kits, 1 Canadian product and 3 Chinese products,were used in the comparative study. Each pool consisted of 5 sera, and the 5 single sera were tested as controls. The tests were carri...Four enzyme immunoassay (EIA) test kits, 1 Canadian product and 3 Chinese products,were used in the comparative study. Each pool consisted of 5 sera, and the 5 single sera were tested as controls. The tests were carried out according to the instructions, keeping the same dilution of each serum in single and pool samples. It was found that with the Canadian kit,the positive and negative results of opled sera had no difference from that of the controls (P>0. 10). In the case of Chinese Yali and Kehua kits, the positive results of pooled sera showed no difference from the controls (P >0. 10), but the optical density (OD) of negative opls were increased (P < 0. 01 ), though quite distant from the cut-off values. In the case of Changzheng kit, the OD of opitive opls were significantly lower than those of the controls (P < 0. 05 ), and weak positive samples missed the detection. However this problem could be overcome by blocking the microwells beforehand. Our experiment demonstrate that not all EIA test kits are suitable for screening opls for antithey to hepatitis C virus, and that it is important to assess the sensitivity of the EIA kit to be used for this purpose.展开更多
Background: Tuberculosis (TB) diagnostics, such as Xpert MTB/RIF, is still limited by cost. Testing of pooled samples from presumptive TB patients has been thought as a cost-saving strategy to diagnose TB. We assessed...Background: Tuberculosis (TB) diagnostics, such as Xpert MTB/RIF, is still limited by cost. Testing of pooled samples from presumptive TB patients has been thought as a cost-saving strategy to diagnose TB. We assessed the utility and cost-saving of pooled Xpert MTB/RIF testing strategy for the diagnosis of TB in Mwanza, Tanzania. Methods: Sputum samples from Presumptive TB patients were submitted to TB laboratory for routine diagnosis of TB using Xpert MTB/RIF. The TB results from the individual sputum samples were used as the reference standard and were concealed to the investigating laboratory technicians. The remainder of samples were collected serially and were pooled (5 samples per pool) for testing. The agreement of the results between individual sample testing against pooled sample testing and cost-savings was assessed. Results: A total of 250 sputum samples from presumptive TB patients were analyzed and 50 pools were made with each pool containing 5 samples. Of the 50 sputum pools made, Mycobacterium tuberculosis (MTB) was detected in 17 (34.0%) pools. Results from the individual sputum samples MTB/RIF testing were retrieved for all 250 samples and there were 28 (11.2%) samples in which MTB was detected whereas 222 (88.8%) samples had no MTB detected. Following re-analysis of positive pools, all 28 (100%) individual positive MTB samples were detected within the 17 positive pools, with 1 to 3 individual MTB positive samples per pool. The individual sputum samples were correctly identified by pooled sputum on Xpert MTB/RIF testing, with the sensitivity of 100% and specificity of 100%. Using pooling of sputum samples strategy, we saved 46.0% (115/250) of the cartridges. Conclusion: The pooled sputum testing strategy reduced cartridge costs by 46.0% and has the potential to increase the affordability of Xpert MTB/RIF testing in countries with limited resources, such as Tanzania.展开更多
Background Bladder leiomyoma is an uncommon type of bladder neoplasms. Most publications are reports of isolated cases. The influence of tumor size on patients＇ early symptoms was seldom analyzed. We aim to investiga...Background Bladder leiomyoma is an uncommon type of bladder neoplasms. Most publications are reports of isolated cases. The influence of tumor size on patients＇ early symptoms was seldom analyzed. We aim to investigate the clinical characteristics of bladder leiomyoma and the influence of tumor size on patients＇ symptoms in Chinese population. Methods We reviewed the medical records of eight patients diagnosed with bladder leiomyoma at our department, collected 53 cases from Chinese National Knowledge Infrastructure （CNKI）, Wangfang data base, and Chinese Biological Medicine Disk, and performed a pooled analysis. The clinical characteristics of the patients were analyzed and then classified into symptomatic and asymptomatic groups. The association between tumor size and the occurrence of symptoms was evaluated. Furthermore, Logistic regression model was constructed to discriminate variables. Results Women comprised the majority of the patients （49/61, 80.3%）. The mean age and tumor size were （42.3＋14.0） years and （45.0＋25.7） mm, respectively. Among all the symptoms, irritative symptoms occurred most frequently （37.7%, 23/61）, followed by obstructive urinary symptoms （31.1%, 19/61）, hematuria （24.6%, 15/61 ）, and abdominal bulge or pain （14.8%, 9/61）. In our study, patients who were 45 years old or younger tended to be asymptomatic compared with elder ones （14/36 vs. 3/25, P=-0.021）. The histological, as well as anatomical, location of tumor, did not show significant differences between symptomatic and asymptomatic patients （P=-0.306 and 0.700）. Tumors larger than 30 mm in the greatest diameter would cause clinical symptoms such as obstructive urinary symptoms （P=0.048） and irritative symptoms （P=0.037）. Logistic regression confirmed the association between tumor size and the occurrence of symptoms, which was related with age. Conclusions Bladder leiomyoma occurs mainly in women and most frequently with irritative symptoms. The occurrence of symptoms is related to tumor size rather than the location： In this setting, patients with endovesical tumors smaller than 30 mm in the greatest diameter tended to be asymptomatic, which were usually treated with transurethrai resection of bladder tumor.展开更多
Artificial aeration system for aquaculture ponds becomes essential to meet the oxygen requirement posed by the aquatic species.The performance of an aerator is generally mea-sured in terms of standard aeration efficie...Artificial aeration system for aquaculture ponds becomes essential to meet the oxygen requirement posed by the aquatic species.The performance of an aerator is generally mea-sured in terms of standard aeration efficiency(SAE),which is significantly affected by the different geometric and dynamic parameters of the aerator.Therefore,to enhance the aer-ation performance of an aerator,these parameters need to be optimized.In the present study,a perforated pooled circular stepped cascade(PPCSC)aerator was developed,and the geometric and dynamic parameters of the developed aerator were optimized using the hybrid ANN-PSO technique for maximizing its aeration efficiency.The geometric parameters include consecutive step width ratio(W_(i-1)/W_(i))and the perforation diameter to the bottom-most radius ratio(d/R_(b)),whereas the dynamic parameter includes the water flow rate(Q).A 3–6-1 ANN model coupled with particle swarm optimization(PSO)approach was used to obtain the optimum values of geometric and dynamic parameters correspond-ing to the maximum SAE.The optimal values of the consecutive step width ratio(W_(i-1)/W_(i)),the perforation diameter to the bottom-most radius ratio(d/R_(b)),and the water flow rate(Q)for maximizing the SAE were found to be 1.15,0.0027 and 0.0167 m^(3)/s,respectively.The cross-validation results showed a deviation of 3.07%between the predicted and experimen-tal SAE values,thus confirming the adequacy of the proposed hybrid ANN-PSO technique.展开更多
In this study,the rotary movement of the tungsten needle in gas tungsten arc welding(GTAW)process was realized by direct current motor.The arc characteristics,the flow of molten pool and the microstructure and propert...In this study,the rotary movement of the tungsten needle in gas tungsten arc welding(GTAW)process was realized by direct current motor.The arc characteristics,the flow of molten pool and the microstructure and properties of the weld bead were studied.The results showed that the rotary motion of the tungsten needle transferred circumferential momentum to the arc as well as the molten pool,thereby conferring the latter with rotating fluid flow characteristics.Under the action of a relatively spiraling shielding gas,arc constriction occurred,and molten pool width dropped considerably.A finer and more uniform precipitated phase in the matrix,as well as a fewer large-medium pores,were achieved in the 5A06 aluminum alloy weld metal using this modified GTAW process,which noticeably increased the bending strength and tensile strength of weld metal and the microhardness of fusion zone.展开更多
Pulmonary nodules represent an early manifestation of lung cancer.However,pulmonary nodules only constitute a small portion of the overall image,posing challenges for physicians in image interpretation and potentially...Pulmonary nodules represent an early manifestation of lung cancer.However,pulmonary nodules only constitute a small portion of the overall image,posing challenges for physicians in image interpretation and potentially leading to false positives or missed detections.To solve these problems,the YOLOv8 network is enhanced by adding deformable convolution and atrous spatial pyramid pooling(ASPP),along with the integration of a coordinate attention(CA)mechanism.This allows the network to focus on small targets while expanding the receptive field without losing resolution.At the same time,context information on the target is gathered and feature expression is enhanced by attention modules in different directions.It effectively improves the positioning accuracy and achieves good results on the LUNA16 dataset.Compared with other detection algorithms,it improves the accuracy of pulmonary nodule detection to a certain extent.展开更多
Among the rolling hills and vineyards of the Tuscan countryside lies one of the most impressive tourist attractions not only in Italy,but in the entire world-a cascade(小瀑布)of white limestone pools overflowing with ...Among the rolling hills and vineyards of the Tuscan countryside lies one of the most impressive tourist attractions not only in Italy,but in the entire world-a cascade(小瀑布)of white limestone pools overflowing with warm turquoise(绿松石色)water known as Cascate del Mulino.展开更多
Addressing global warming,a common change today,requires achieving peak carbon dioxide emissions and carbon neutrality(also referred to as the dual carbon goals).Enhancing research on the carbon cycle is urgently need...Addressing global warming,a common change today,requires achieving peak carbon dioxide emissions and carbon neutrality(also referred to as the dual carbon goals).Enhancing research on the carbon cycle is urgently needed as the foundation.Water,a key carrier in the carbon cycle,necessitates investigation into groundwater carbon pools’contribution to atmospheric carbon sinks.This study assessed carbon stocks in the Yinchuan Basin’s soil and groundwater carbon pools.Findings indicate the basin’s surface soils contain approximately 24.16 Tg of organic carbon and a total of 60.01 Tg of carbon.In contrast,the basin’s groundwater holds around 4.90 Tg of carbon,roughly one-fifth of the organic carbon in surface soils.Thus,groundwater and soil carbon pools possess comparable carbon stocks,underscoring the importance of the groundwater carbon pool.Studies on terrestrial carbon balance should incorporate groundwater carbon pools,which deserve increased focus.Evaluating groundwater carbon pools’contributions is vital for achieving the dual carbon goals.展开更多
文摘We examine Africa's vaccine manufacturing potential,spurred by the coronavirus disease 2019(COVID-19)pan-demic,while critically analyzing vaccine price inequities and procurement strategies during the pandemic,with anticipation of future outbreaks.Although Africa consumes approximately 25%of the global vaccine supply,over 99%of these vaccines are produced outside the continent,primarily due to insufficient local investment.Vaccine procurement strategies have relied heavily on pooled procurement mechanisms and tiered-pricing mod-els,predominantly controlled by external organizations.Significant disparities in vaccine pricing have resulted in vaccine price inequities,with evidence suggesting price discrimination,where different prices are charged for the same vaccine across countries and regions.While vaccine prices are only one component of vaccination cam-paign costs,the inequitable pricing of vaccines poses serious challenges to fair access,especially in low-income countries.Given the inevitability of future pandemics and other outbreaks,the central question remains:Does Africa possess the capacity to strengthen its vaccine production infrastructure and reduce dependency on ex-ternal suppliers?Our review reveals that,with robust political commitment,enhanced investment in Research and Development,and leveraging the heterogeneous nature of the regional bloc,Africa has made strides toward establishing vaccine manufacturing hubs with the potential for substantial capacity expansion.Furthermore,we argue for a regional campaign based on the principles of the fair priority model as an ethical framework for vaccine procurement,which prioritizes need and ensures equitable distribution,thereby complementing existing pooled procurement arrangements in times of future pandemics.This paper concludes with two key recommen-dations based on lessons learned from the COvID-19 crisis and future preparedness.First,Africa must push for a transparent and equitable tiered-pricing structure to ensure affordability for all Second,intentional and sustained investment in R&D is critical to addressing systemic inequities in vaccine supply,not only for cOVID-19 but for future outbreaks and routine immunization programs.
文摘The P24 antigen test, HIV RNA PCR test, HIV isolation/culture and fourth-generation HIV uniform Ag/Ab assay are being utilized in diagnosing acute HIV infection in different labs. Many factors limit the use of screening for acute HIV in high-risk populations, in blood donors and during voluntary HIV testing, including, cost, technique, sensitivity and specificity. In this review we explore a new NAAT method which involves HIV RNA RT-PCR on pooled samples. This technique is able to screen for acute infections in a large testing volume and may be used as a screening method in high-risk populations and blood donors.
文摘Often in longitudinal studies, some subjects complete their follow-up visits, but others miss their visits due to various reasons. For those who miss follow-up visits, some of them might learn that the event of interest has already happened when they come back. In this case, not only are their event times interval-censored, but also their time-dependent measurements are incomplete. This problem was motivated by a national longitudinal survey of youth data. Maximum likelihood estimation (MLE) method based on expectation-maximization (EM) algorithm is used for parameter estimation. Then missing information principle is applied to estimate the variance-covariance matrix of the MLEs. Simulation studies demonstrate that the proposed method works well in terms of bias, standard error, and power for samples of moderate size. The national longitudinal survey of youth 1997 (NLSY97) data is analyzed for illustration.
文摘Purpose: To assess the efficacy and safety of Olaparib, a PARP inhibitor on progression-free survival (PFS), objective response rate (ORR) and overall survival (OS) in patients with breast and ovarian cancer. Methods: Research data from clinical trials through PubMed, Science Citation Index, Elsevier Science Direct and Cochrane Library of all published studies exploring the PFS, ORR or OS of Olaparib for maintenance monotherapy on survival in breast and ovarian cancer were analysed. Pooled estimates of the ORR, weighted medians of PFS and OS from all Olaparib were calculated. Assessment of quality and level of evidence was assigned by Cochrane guidelines and guidelines of Oxford Centre for Evidence-Based Medicine. Results: Data of 893 patients (731 olaparib;162 control) from 6 trials, 2 randomised controlled trials and 4 non-randomised trials, were included. The overall median weighted PFS and OS in patients treated with Olaparib were 5.9 and 19.1 months, respectively. The pooled ORR was 25%. Olaparib showed a greater effect on PFS in patients with both wild-type BRCA and BRCA mutant gene. The most common toxicity were nausea and vomiting. Conclusions: Olaparib as maintenance monotherapy for breast and ovarian cancer is associated with promising outcomes including increased response rate and improved PFS. Its potential in clinical application is needed for further investigation in phase III trials.
文摘Background: Childhood tuberculosis accounts for about 10% of estimated TB cases in the world. Despite advances in diagnostics, childhood TB remains a challenge. We evaluated pooling method and testing with GeneXpert MTB/RIF in southern Ethiopia. Methods: This is a cross-sectional study in presumptive TB children st, 2nd and pooled samples. Results: Of 340 presumptive TB cases enrolled, 96 and 244 children submitted gastric aspirate and sputum samples respectively. Of 1020 samples collected (282 gastric aspirate and 738 sputum samples), 38 (3.7%) were positive by Xpert (10 (3.5%) from gastric aspirate and 28 (3.8%) from sputum sample). Similarly, 8 (1.2%) of sputum samples were positive by ZN but none from gastric aspirate. Of 244 children who submitted sputum samples, 3 (1.2%) were bacteriologically positive compared to 12 (4.9%) by Xpert. Of 96 children who submitted gastric aspirate samples, none were positive by ZN while 5 (5.2%) were positive by Xpert. Of bacteriologically confirmed TB cases 0.9% was by ZN and 4.7% by Xpert, an increase of 3.8%. Pooled testing increased positivity by 0.3% for ZN and 1.5% by Xpert compared to the 1st sample. Conclusions: Xpert MTB/RIF testing increases yield compared to ZN testing for gastric aspirate samples. The same-day approach and pooling samples improves efficient use of cartridge, reduce the number of visits for seeking diagnosis and save resources.
文摘Four enzyme immunoassay (EIA) test kits, 1 Canadian product and 3 Chinese products,were used in the comparative study. Each pool consisted of 5 sera, and the 5 single sera were tested as controls. The tests were carried out according to the instructions, keeping the same dilution of each serum in single and pool samples. It was found that with the Canadian kit,the positive and negative results of opled sera had no difference from that of the controls (P>0. 10). In the case of Chinese Yali and Kehua kits, the positive results of pooled sera showed no difference from the controls (P >0. 10), but the optical density (OD) of negative opls were increased (P < 0. 01 ), though quite distant from the cut-off values. In the case of Changzheng kit, the OD of opitive opls were significantly lower than those of the controls (P < 0. 05 ), and weak positive samples missed the detection. However this problem could be overcome by blocking the microwells beforehand. Our experiment demonstrate that not all EIA test kits are suitable for screening opls for antithey to hepatitis C virus, and that it is important to assess the sensitivity of the EIA kit to be used for this purpose.
文摘Background: Tuberculosis (TB) diagnostics, such as Xpert MTB/RIF, is still limited by cost. Testing of pooled samples from presumptive TB patients has been thought as a cost-saving strategy to diagnose TB. We assessed the utility and cost-saving of pooled Xpert MTB/RIF testing strategy for the diagnosis of TB in Mwanza, Tanzania. Methods: Sputum samples from Presumptive TB patients were submitted to TB laboratory for routine diagnosis of TB using Xpert MTB/RIF. The TB results from the individual sputum samples were used as the reference standard and were concealed to the investigating laboratory technicians. The remainder of samples were collected serially and were pooled (5 samples per pool) for testing. The agreement of the results between individual sample testing against pooled sample testing and cost-savings was assessed. Results: A total of 250 sputum samples from presumptive TB patients were analyzed and 50 pools were made with each pool containing 5 samples. Of the 50 sputum pools made, Mycobacterium tuberculosis (MTB) was detected in 17 (34.0%) pools. Results from the individual sputum samples MTB/RIF testing were retrieved for all 250 samples and there were 28 (11.2%) samples in which MTB was detected whereas 222 (88.8%) samples had no MTB detected. Following re-analysis of positive pools, all 28 (100%) individual positive MTB samples were detected within the 17 positive pools, with 1 to 3 individual MTB positive samples per pool. The individual sputum samples were correctly identified by pooled sputum on Xpert MTB/RIF testing, with the sensitivity of 100% and specificity of 100%. Using pooling of sputum samples strategy, we saved 46.0% (115/250) of the cartridges. Conclusion: The pooled sputum testing strategy reduced cartridge costs by 46.0% and has the potential to increase the affordability of Xpert MTB/RIF testing in countries with limited resources, such as Tanzania.
文摘Background Bladder leiomyoma is an uncommon type of bladder neoplasms. Most publications are reports of isolated cases. The influence of tumor size on patients＇ early symptoms was seldom analyzed. We aim to investigate the clinical characteristics of bladder leiomyoma and the influence of tumor size on patients＇ symptoms in Chinese population. Methods We reviewed the medical records of eight patients diagnosed with bladder leiomyoma at our department, collected 53 cases from Chinese National Knowledge Infrastructure （CNKI）, Wangfang data base, and Chinese Biological Medicine Disk, and performed a pooled analysis. The clinical characteristics of the patients were analyzed and then classified into symptomatic and asymptomatic groups. The association between tumor size and the occurrence of symptoms was evaluated. Furthermore, Logistic regression model was constructed to discriminate variables. Results Women comprised the majority of the patients （49/61, 80.3%）. The mean age and tumor size were （42.3＋14.0） years and （45.0＋25.7） mm, respectively. Among all the symptoms, irritative symptoms occurred most frequently （37.7%, 23/61）, followed by obstructive urinary symptoms （31.1%, 19/61）, hematuria （24.6%, 15/61 ）, and abdominal bulge or pain （14.8%, 9/61）. In our study, patients who were 45 years old or younger tended to be asymptomatic compared with elder ones （14/36 vs. 3/25, P=-0.021）. The histological, as well as anatomical, location of tumor, did not show significant differences between symptomatic and asymptomatic patients （P=-0.306 and 0.700）. Tumors larger than 30 mm in the greatest diameter would cause clinical symptoms such as obstructive urinary symptoms （P=0.048） and irritative symptoms （P=0.037）. Logistic regression confirmed the association between tumor size and the occurrence of symptoms, which was related with age. Conclusions Bladder leiomyoma occurs mainly in women and most frequently with irritative symptoms. The occurrence of symptoms is related to tumor size rather than the location： In this setting, patients with endovesical tumors smaller than 30 mm in the greatest diameter tended to be asymptomatic, which were usually treated with transurethrai resection of bladder tumor.
文摘Artificial aeration system for aquaculture ponds becomes essential to meet the oxygen requirement posed by the aquatic species.The performance of an aerator is generally mea-sured in terms of standard aeration efficiency(SAE),which is significantly affected by the different geometric and dynamic parameters of the aerator.Therefore,to enhance the aer-ation performance of an aerator,these parameters need to be optimized.In the present study,a perforated pooled circular stepped cascade(PPCSC)aerator was developed,and the geometric and dynamic parameters of the developed aerator were optimized using the hybrid ANN-PSO technique for maximizing its aeration efficiency.The geometric parameters include consecutive step width ratio(W_(i-1)/W_(i))and the perforation diameter to the bottom-most radius ratio(d/R_(b)),whereas the dynamic parameter includes the water flow rate(Q).A 3–6-1 ANN model coupled with particle swarm optimization(PSO)approach was used to obtain the optimum values of geometric and dynamic parameters correspond-ing to the maximum SAE.The optimal values of the consecutive step width ratio(W_(i-1)/W_(i)),the perforation diameter to the bottom-most radius ratio(d/R_(b)),and the water flow rate(Q)for maximizing the SAE were found to be 1.15,0.0027 and 0.0167 m^(3)/s,respectively.The cross-validation results showed a deviation of 3.07%between the predicted and experimen-tal SAE values,thus confirming the adequacy of the proposed hybrid ANN-PSO technique.
基金supported by National Natural Science Foundation of China(52175305)National Natural Science Foundation of China(U22B20127)Taishan Scholars Project(tstp20230618).
文摘In this study,the rotary movement of the tungsten needle in gas tungsten arc welding(GTAW)process was realized by direct current motor.The arc characteristics,the flow of molten pool and the microstructure and properties of the weld bead were studied.The results showed that the rotary motion of the tungsten needle transferred circumferential momentum to the arc as well as the molten pool,thereby conferring the latter with rotating fluid flow characteristics.Under the action of a relatively spiraling shielding gas,arc constriction occurred,and molten pool width dropped considerably.A finer and more uniform precipitated phase in the matrix,as well as a fewer large-medium pores,were achieved in the 5A06 aluminum alloy weld metal using this modified GTAW process,which noticeably increased the bending strength and tensile strength of weld metal and the microhardness of fusion zone.
文摘Pulmonary nodules represent an early manifestation of lung cancer.However,pulmonary nodules only constitute a small portion of the overall image,posing challenges for physicians in image interpretation and potentially leading to false positives or missed detections.To solve these problems,the YOLOv8 network is enhanced by adding deformable convolution and atrous spatial pyramid pooling(ASPP),along with the integration of a coordinate attention(CA)mechanism.This allows the network to focus on small targets while expanding the receptive field without losing resolution.At the same time,context information on the target is gathered and feature expression is enhanced by attention modules in different directions.It effectively improves the positioning accuracy and achieves good results on the LUNA16 dataset.Compared with other detection algorithms,it improves the accuracy of pulmonary nodule detection to a certain extent.
文摘Among the rolling hills and vineyards of the Tuscan countryside lies one of the most impressive tourist attractions not only in Italy,but in the entire world-a cascade(小瀑布)of white limestone pools overflowing with warm turquoise(绿松石色)water known as Cascate del Mulino.
基金supported by the third scientific survey project in Xinjiang(2022xjkk0300)the public welfare geological survey projects initiated by the China Geological Survey(DD20190296,DD20221731).
文摘Addressing global warming,a common change today,requires achieving peak carbon dioxide emissions and carbon neutrality(also referred to as the dual carbon goals).Enhancing research on the carbon cycle is urgently needed as the foundation.Water,a key carrier in the carbon cycle,necessitates investigation into groundwater carbon pools’contribution to atmospheric carbon sinks.This study assessed carbon stocks in the Yinchuan Basin’s soil and groundwater carbon pools.Findings indicate the basin’s surface soils contain approximately 24.16 Tg of organic carbon and a total of 60.01 Tg of carbon.In contrast,the basin’s groundwater holds around 4.90 Tg of carbon,roughly one-fifth of the organic carbon in surface soils.Thus,groundwater and soil carbon pools possess comparable carbon stocks,underscoring the importance of the groundwater carbon pool.Studies on terrestrial carbon balance should incorporate groundwater carbon pools,which deserve increased focus.Evaluating groundwater carbon pools’contributions is vital for achieving the dual carbon goals.
