Accuracy and precision of dried urine spot method for the detection of Schistosoma mansoni circulating cathodic antigens in resource-limited settings

Background The World Health Organization recommends the use of Schisto point-of-care circulating cathodic anti-gens(Schisto POC-CCA)for screening of Schistosoma mansoni as it offers better sensitivity than microscopy.However,there are limitation facing the use of this method including timely availability of the test cassettes.The aim of this study was to determine the reliability of dried urine spot(DUS)method for collection of urine and detection of S.mansoni using Schisto POC-CCA cassettes in a resource-limited settings.Methods A cross-sectional study was conducted between October and November 2022 among 250 primary school children in Sengerema District,northwestern Tanzania.S.mansoni CCA was detected in filter paper-based DUSs,liquid urine using DUS Schisto POC-CCA(index),and direct urine Schisto POC-CCA(comparator)methods respectively.S.mansoni eggs in stool were detected using duplicate Kato-Katz(KK)method.The measures of accuracy were com-puted and compared between the index and comparator methods.The strength of agreement between inter-raters precisions was tested using Cohen's kappa(k).Results This study revealed S.mansoni prevalence rates of 28.8%,54.0%and 50.8%by duplicate KK,direct urine Schisto POC-CCA and DUS Schisto POC-CCA methods respectively.The mean intensity of infection among infected participants Was 86.3 eggs per gram of stool(EPG)ranging from 12.0 EPG to 824.0 EPG.The sensitivity of DUS Schisto POC-CCA and direct urine Schisto POC-CCA Was 94.44%(95%CI:89.15-99.74%)and 97.22%(95%CI:93.43-100.00%)respectively.The DUS Schisto POC-CCA method had slightly higher specificity(66.85%)than direct urine Schisto POC-CCA method(63.48%).The accuracy of the DUS Schisto POC-CCA Was found to be slightly high(74.80%,95%CI:68.94-79.06%)compared to that of direct urine Schisto POC-CCA(73.20%,95%CI:67.25-78.59%).There was good agreement between two laboratory technologists who performed the DUS Schisto POC-CCA method on similar samples(k=0.80,95%CI:0.59-0.95).Conclusions The DUS Schisto POC-CCA method had comparable S.mansoni detection accuracy to direct urine Schisto POC-CCA.This suggests that the method could be a potential alternative to direct urine Schisto POC-CCA for screening S.mansoni in resource-limited situations.

Two stages power generation test of the hot dry rock exploration and production demonstration project in the Gonghe Basin,northeastern Qinghai-Tibet plateau,China

The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in efficient drilling and completion,reservoir construction,and fracture simulation.In 2019,China Geological Survey(CGS)initiated a demonstration project of HDR exploration and production in the Gonghe Basin,aiming to overcome the setbacks faced by HDR projects.Over the ensuing four years,the Gonghe HDR project achieved the first power generation in 2021,followed by the second power generation test in 2022.After establishing the primary well group in the initial phase,two directional wells and one branch well were drilled.Noteworthy progress was made in successfully constructing the targeted reservoir,realizing inter-well connectivity,power generation and grid connection,implementing of the real-time micro-seismic monitoring.A closed-loop technical validation of the HDR exploration and production was completed.However,many technical challenges remain in the process of HDR industrialization,such as reservoir fracture network characterization,efficient drilling and completion,multiple fracturing treatment,continuous injection and production,as well as mitigation of induced seismicity and numerical simulation technology.

饱水-风干作用下砂岩断裂韧度与抗拉强度研究

为了解考虑时间效应的饱水-风干循环作用时砂岩Ⅰ型断裂韧度、抗拉强度的变化规律及其相关性,选取三峡库区库水位变幅带砂岩为研究对象,对周期性饱水-风干循环状态的砂岩试样开展了三点弯曲断裂韧度试验和劈裂抗拉强度试验。试验结果表明:在饱水风干循环作用下,砂岩的断裂韧度和抗拉强度软化效应明显,且试验前期砂岩强度软化效应较大,后期趋于稳定。同时,在同一时间周期内,砂岩试样的断裂韧度和抗拉强度具有相近的软化系数。最后通过数据拟合得到了砂岩断裂韧度与抗拉强度的相关关系,拟合相关性较高,并通过与相关其他试验成果的比较,验证了公式的可靠性。

冬凌草甲素长循环冻干脂质体的制备及大鼠体内药动学研究

目的:研究处方及工艺,制备冬凌草甲素长循环冻干脂质体,延长冬凌草甲素体内循环时间。方法:乙醇注入法制备冬凌草甲素长循环脂质体,冷冻干燥技术制备脂质体冻干制剂。使用葡聚糖凝胶柱纯化脂质体,单因素实验考察不同处方因素对脂质体包封率的影响,研究冻干脂质体复溶后粒径大小、分布及体外释放曲线。大鼠尾静脉给药后,HPLC测定血药浓度,KineticaTM软件计算药动学参数,比较长循环脂质体与普通制剂的药动学特性。结果:最优长循环脂质体处方为:大豆磷脂∶胆固醇∶DSPE-PEG 2000=1∶0.5∶1.8(w/w),药脂比为1∶6(w/w)。葡萄糖∶甘露醇=3∶1合用作为冻干保护剂,脂质体包封率约65%。复溶后脂质体平均粒径164 nm,分布均匀,长循环脂质体体外释放具缓释效果。大鼠静脉注射冬凌草甲素制剂均符合二室模型,长循环冻干脂质体的MRT约为普通脂质体及溶液组的2倍和6倍;AUC约为普通脂质体及溶液组的2倍及3倍,差异均具统计学意义(P<0.05)。结论:选用合适的处方及工艺可得到包封率较高的冬凌草甲素长循环脂质体冻干制剂,显著提高冬凌草甲素大鼠体内循环时间和生物利用度。

Integration of Growing Milk Vetch in Winter and Reducing Nitrogen Fertilizer Application Can Improve Rice Yield in Double-Rice Cropping System

To study whether integrative fertilization [growing milk vetch in winter and reducing the dose of chemical nitrogen(N) fertilizer] can improve rice yield, and to reveal the underlying regulatory mechanisms for integrative fertilization, a three-year field trial including two treatments, milk vetch-rice-rice(MRR) and winter fallow-rice-rice(FRR), was conducted in 2010, 2011 and 2012.Our results demonstrated that the MRR treatment could significantly improve rice yield compared with the FRR treatment, especially when the application ratio of milk vetch and chemical fertilizer was 1:2.MRR treatment increased the effective panicle number and the spikelet number per panicle.In addition, a higher tillering number, leaf area index, photosynthetic-potential and photosynthetic-potential to grain ratio were observed in MRR treatment, which could provide enough dry matter for yield formation.Moreover, in MRR treatment, we discovered a higher transportation ratio and transformation ratio of dry matter in culm and leaves, and a stronger total sink capacity and spikelet-root bleeding intensity at the heading stage and 15 d after heading.Furthermore, the MRR treatment showed higher total N, phosphorus and potassium uptakes than FRR treatment, which was associated with the higher root dry weight in each soil layers.These results suggest that growing milk vetch in winter can improve rice yield under less chemical N fertilizer application, which is due to the improvement of soil nutrient status and the increased of rice root growth and development.

市政污泥耦合燃煤电厂发电关键因素分析与展望

分析市政污泥耦合燃煤电厂发电的政策形势和应用现状,总结市政污泥耦合燃煤电厂发电工艺流程中的关键因素,包括含水率、热值、含砂率、污泥干化和耦合焚烧过程中重金属、二噁英等污染物的产生和抑制方法,并对比各种市政污泥深度脱水及干化工艺的优缺点。对煤粉锅炉和循环流化床锅炉耦合市政污泥的技术路线进行对比,进而分析了耦合污泥对不同炉型发电工艺的影响。研究结果表明:为更好地实施市政污泥耦合燃煤发电项目,应减少污泥中的含砂量,降低干化设备和锅炉设备的磨损;同时对耦合燃烧产生的飞灰和炉渣进行实时监测和治理,减少二次污染;创新协调水务企业、燃煤发电企业、电网企业和政府关系,保证项目技术经济性。

Analysis of rainfall variability over Tanzania in late austral summer

Based on site-observation data,NCEP–NCAR reanalysis data,and Climatic Research Unit gridded data,the rainfall variability over Tanzania during late austral summer(January–March,JFM)was analyzed for the period 1961–2011.Further,the associated atmospheric circulation and SST anomalies(SSTAs)were explored to understand the mechanisms of dry-and wet-year cases based on an interannual time scale.The correlation,Morlet wavelet power spectrum,and composite analysis methods were employed.The results showed that the JFM standardized rainfall anomaly time series exhibited significant time scales of variability at interannual(2–8 years)and quasidecadal(8–12 years).During dry years,anomalous anticyclonic northeasterly flow originating from western tropical Indian and southeast trades from the Indian Ocean to the southeast were associated with subsiding dry air,which resulted in suppression of rainfall as observed.In the typical wet-year cases,meanwhile,anomalous westerlies from the tropical and southeast Atlantic were strengthened over the Congo basin,delivering more precipitation to the region.Significant correlation was exhibited over the western tropical and southeast Indian Ocean,as well as the southeast and tropical Atlantic Ocean.These SSTA patterns favored atmospheric general circulation anomalies that were closely related to JFM rainfall over Tanzania.

Modelling the Potential Distribution of <i>Vitellaria paradoxa</i>subsp. <i>nilotica</i>(C.F. Gaertn) across the Kidepo Landscape of Uganda in the Face of Climate Change

Climate change and human activities are increasingly linked with the extinction of species globally. In semi-arid regions, these pressures threaten the natural distribution and ecology of species. The threat that the shea butter tree (Vitellaria paradoxa subsp. nilotica) faces from human activity is well researched yet the sensitivity of its distribution to climate change remains barely known. We set out to assess the potential distribution of Vitellaria under different climate change scenarios using a MaxEnt. A current distribution model was first developed using only biophysical variables of soil type, temperature, precipitation, land use type, and elevation. This model was then projected onto two global warming scenarios (RCP 4.5 & RCP 8.5) for 2050 and 2070 using multi-model averages (BCC-CSM, CSM4, and MIROC5) derived from three general circulation models. Reductions are seen in distribution area across the landscape with soil type being the most important variable. These results draw useful implications for conservation of Vitellaria in that they show how it is vulnerable is to a changing climate as its natural range is mostly reduced. Since climate change is important in the distribution of the shea butter tree, the areas with highest suitability in this study can be used in establishing the Shea butter tree sustainable use zones/area within the Kidepo Critical Landscape (KCL), Uganda.

Statistical Prediction of Wet and Dry Periods in theComahue Region (Argentina)

General features of rainy season with excess or deficits are analyzed using standardized precipitation index (SPI) in Limay and Neuquen River basins. Results indicate that most of dry and wet periods persist less than three months in both basins. Furthermore, an increase of rainfall variability over time is observed in the Limay river basin but it is not detected in the Neuquen river basin. There is a tendency for wet (dry) periods to take place in El Ni?o (La Ni?a) years in both basins. Rainfall in both basins, have an important annual cycle with its maximum in winter. In addition, possible causes of extreme rainy seasons over the Limay River Basin are detailed. The main result is that the behavior of low level precipitation systems displacing over the Pacific Ocean in April influences the general hydric situation during the whole rainy season. In order to establish the existence of previous circulation patterns associated with interannual SPI variability, the composite fields of wet and dry years are compared. The result is that rainfall is related to El Ni?o- Southern Oscillation (ENSO) phenomenon and circulation over the Pacific Ocean. The prediction scheme, using multiple linear regressions, showed that 46% of the SPI variance can be explained by this model. The scheme was validated by using a cross-validation method, and significant correlations are detected between observed and forecast SPI. A polynomial model is used and it little improved the linear one, explaining the 49% of the SPI variance. The analysis shows that circulation indicators are useful to predict winter rainfall behavior.

白光“消痈法”辨证分型治疗胃溃疡

白光教授认为胃溃疡是肝郁、食滞、痰湿、血瘀等诸邪化火成痈,宜以痈论治。活动期清热散火消痈;愈合期和瘢痕期养阴益气活血。白光教授将活动期分为五种证型:肝郁化火化肝煎合左金丸,食滞化火用保和丸,痰湿热壅黄连温胆汤,血瘀积热失笑散合血府逐瘀汤,寒热错杂半夏泻心汤合柴胡桂枝干姜汤;愈合期和瘢痕期百合乌药汤,注重保护胃气和预防调护。附病案二例。

Detection of Schistosoma mansoni DNA using polymerase chain reaction from serum and dried blood spot card samples of an adult population in North-western Tanzania

Background:Real-time polymerase chain reaction(PCR)is a sensitive and specific method for diagnosing schistosomiasis.However,this method should be performed in a laboratory,usually located distant from the sample collection site.Therefore,it is important to have fast sampling preservation methods,which allow simple transport prior to DNA extraction and amplification.The aim of this study was to verify if blood samples applied to filter paper are suitable for analysis of Schistosoma mansoni DNA by real-time PCR.Methods:A cross-sectional study was conducted among 100 study participants aged 17 to 70 years in a fishing village on the southern shore of Lake Victoria,fanzania.Serum samples and ethylenediaminetetraacetic acid(EDTA)-anticoagulated whole blood for preparation of dried blood spots(DBS)were collected to test for Schistosoma mansoni infection by real-time PCR.A combined diagnostic reference of positive results of serum-based real-time PCR and the Kato-Katz(KK)method was used for analysis.Sensitivity and negative predictive value(NPV)were calculated.The Wilcoxon signed-rank test was chosen to compare the mean cycle threshold(Ct)values from serum and DBS.Results:According to the reference,92.5%S.mansoni positive samples were determined.The serum-based real-time PCR performed excellently with 95.4%sensitivity,whereas the DBS-based real-time PCR showed a low sensitivity(45.4%).The Ct-values were significantly higher in DBS(median:37.3)than in serum samples(median:27.5,P<0.001),reflecting a lower parasite-specific DNA load on the filter cards.With increasing egg counts,an increase in sensitivity was observed for all methods.The POC-CCA test and the serum-based real-time PCR showed a sensitivity of 100%for medium and severe infections.The DBS real-time PCR showed a sensitivity of only 85.7%even for severe infections.Conclusions:DBS-based real-time PCR did not provide good results in our study and therefore should not be recommended or must be tested concerning temperature of storage,storage duration,use of different filter papers and extraction methods before it is used in future studies.In contrast,our results showed that the POC-CCA test is a sensitive and precise test for detecting S.mansoni infections.

城市干化污泥循环流化床燃烧过程中NO和N_2O的排放特性

在15 kW循环流化床实验台上进行了城市干化污泥的燃烧实验,研究了污泥含水率、燃烧温度、过量空气系数、二次风比率等因素对NO和N_2O排放特性的影响。实验结果表明:污泥含水率从4.5%增加至17.5%时,NO排放浓度明显降低,N_2O排放浓度明显升高;燃烧温度升高,NO排放浓度呈上升趋势,N_2O排放浓度则呈下降趋势;增大过量空气系数会促进NO和N_2O的生成;提高二次风比率可以降低NO和N_2O的排放浓度。城市干化污泥在循环流化床燃烧过程中NO和N_2O的排放浓度高于污泥与煤混烧时的排放浓度,但燃料N向NO和N_2O的转化率低于与煤混烧过程。

A separate-type autothermal CH_(4) dry reforming system with exergy recuperation

Currently,CO_(2) conversion and utilization have become a key to mitigate the global warming.In this study,a novel separate-type autothermal dry reforming of methane(S-ATDRM)system is proposed and simulated,in which the methane dry reforming combined with methane partial oxidation is performed in a circulating fluidized bed with exergy recuperation to eliminate the negative effect of the products of CH_(4) partial oxidation on the DRM reaction and further improve the CO_(2) conversion efficiency.The results demonstrate that this S-ATDRM system can achieve an exergy efficiency of 84.7%,and about 1055.7 kW of exergy can be recuperated from the process for crude syngas cooling and reapplied for pre-heating of feedstocks of CO_(2),O2 and CH_(4).It is found that the largest exergy destruction in this system occurs in the partial oxidation reactor,which occupies ca.45.6%of the whole exergy loss.Comparing with the conventional ATDRM system,although the exergy of S-ATDRM system is decreased by approximately 0.3%,the CO_(2) conversion is substantially increased by about 11.3%.

甘薯枣传统生产工艺优化对品质的影响

以甘薯枣为试材,研究传统生产工艺优化后产品品质的变化的影响。采用干燥法和比色法分别测定甘薯枣的含水率和含糖量,采用质构仪分析甘薯枣质地,并对其外观品质和贮藏品质进行观察。结果表明,热风循环干燥工艺代替传统日晒,真空包装结合灭菌操作代替传统粗包装,可使甘薯枣产品的外观透明度增加,色泽更亮;含水率降低到25.20%,总糖含量增加到33.90%,与对照差异显著;硬度和咀嚼性显著下降,感官弹性和黏附性显著上升,产品质地口感更好;产品保质期从低温贮藏180 d延长到常温贮藏280 d。应用新工艺,产品得率提高到25%,日产能提高,节约了材料和人力成本,在一定程度上促进甘薯枣加工的产业化发展。研究可为甘薯枣新工艺的产业化生产提供理论依据。