Miniature, multi-dichroic instrument for measuring the concentration of multiple fluorophores.

Identification of tumour margins during resection of the brain is critical for improving the post-operative outcomes. Due to the highly infiltrative nature of glioblastoma multiforme (GBM) and limited intraoperative visualization of the tumour margin, incomplete surgical resection has been observed to occur in up to 80 % of GBM cases, leading to nearly universal tumour recurrence and overall poor prognosis of 14.6 months median survival. This research presents a miniaturized, SiPMT-based optical system for simultaneous measurement of powerful DRS and weak auto-fluorescence for brain tumour detection. The miniaturisation of the optical elements confined the spatial separation of eight select wavelengths into footprint measuring 1.5 × 2 × 16 mm. The small footprint enables this technology to be integrated with existing surgical guidance instruments in the operating room. It's dynamic ability to subtract any background illumination and measure signal intensities across a broad range from pW to mWs make this design much more suitable for clinical environments as compared to spectrometer-based systems with limited dynamic ranges and high integration times. Measurements using optical tissue phantoms containing mixed fluorophores demonstrate correlation coefficients between the fitted response and actual concentration using PLS regression being 0.95, 0.87 and 0.97 for NADH, FAD and PpIX , respectively. These promising results indicate that our proposed miniaturized instrument could serve as an effective alternative in operating rooms, assisting surgeons in identifying brain tumours to achieving positive surgical outcomes for patients.

Custom-Design of Strong Electron/Proton Extractor on COFs for Efficient Photocatalytic H2O2 Production.

The development of photocatalysts with continuous electron extraction and rapid proton transfer could kinetically accelerate the artificial photosynthesis, but remains a challenge. Herein, we report the topology-guided synthesis of a high-crystalline triazine covalent organic framework (COF) decorated by uniformly distributed polar oxygen functional groups (sulfonic group or carboxyl) as the strong electron/proton extractor for efficient photocatalytic H2O2 production. It was found that the polarity-based proton transfer as well as electron enrichment in as-obtained COFs played a crucial role in improving the H2O2 photosynthesis efficiency (i.e., with an activity order of sulfonic acid- (SO3H-COF)>carboxyl- (COOH-COF)>hydrogen- (H-COF) functionalized COFs). The strong polar sulfonic acid group in the high-crystalline SO3H-COF triggered a well-oriented built-in electric field and more hydrophilic surface, which serves as an efficient carrier extractor enabling a continuous transportation of the photogenerated electrons and interfacial proton to the active sites (i.e., C atoms linked to -SO3H group). As-accelerated proton-coupled electron transfer (PCET), together with the stabilized O2 adsorption finally leads to the highest H2O2 production rate of 4971 µmol g-1 h-1 under visible light irradiation. Meanwhile, a quantum yield of 15 % at 400 nm is obtained, superior to most reported COF-based photocatalysts.

The importance of the trisomy 21 local cutoff value evaluation for prenatal screening in the second trimester of pregnancy.

OBJECTIVE: The aim of this work was to compare different local cutoff values (LCV) and inline cutoff values (ICV) in pregnant women in the second trimester at high risk for carrying fetuses with trisomy 21. METHODS: This retrospective cohort study analyzed prenatal screening outcomes in pregnant women (n = 311,561). The receiver operating characteristic curve was used to evaluate the diagnostic significance of the trisomy 21 risk value, alpha-fetoprotein, and free beta human chorionic gonadotropin multiple of the median for predicting trisomy 21 risk. The cutoff value corresponding to the maximal Youden index was taken as the LCV. The screening efficiency of both cutoff values was compared. RESULTS: The LCV cutoff value was lower than the ICV cutoff value (1/643 vs 1/270). The sensitivity increased by 19.80%, the positive predictive value decreased by 0.20%, and the false-positive rate increased by 6.50%. CONCLUSION: The LCV should be used to determine trisomy 21 risk, which can increase the detection rate of trisomy 21 in the second trimester.

Maternal prenatal screening programs that predict trisomy 21, trisomy 18, and neural tube defects in offspring.

OBJECTIVE: To determine the efficacy of three different maternal screening programs (first-trimester screening [FTS], individual second-trimester screening [ISTS], and first- and second-trimester combined screening [FSTCS]) in predicting offspring with trisomy 21, trisomy 18, and neural tube defects (NTDs). METHODS: A retrospective cohort involving 108,118 pregnant women who received prenatal screening tests during the first (9-13+6 weeks) and second trimester (15-20+6 weeks) in Hangzhou, China from January-December 2019, as follows: FTS, 72,096; ISTS, 36,022; and FSTCS, 67,631 gravidas. RESULT: The high and intermediate risk positivity rates for trisomy 21 screening with FSTCS (2.40% and 5.57%) were lower than ISTS (9.02% and 16.14%) and FTS (2.71% and 7.19%); there were statistically significant differences in the positivity rates among the screening programs (all P < 0.05). Detection of trisomy 21 was as follows: ISTS, 68.75%; FSTCS, 63.64%; and FTS, 48.57%. Detection of trisomy 18 was as follows; FTS and FSTCS, 66.67%; and ISTS, 60.00%. There were no statistical differences in the detection rates for trisomy 21 and 18 among the 3 screening programs (all P > 0.05). The positive predictive values (PPVs) for trisomy 21 and 18 were highest with FTS, while the false positive rate (FPR) was lowest with FSTCS. CONCLUSION: FSTCS was superior to FTS and ISTS screening and substantially reduced the number of high risk pregnancies for trisomy 21 and 18; however, FSTCS was not significantly different in detecting fetal trisomy 21 and 18 and other confirmed cases with chromosomal abnormalities.

Diagnostic value of maternal alpha-fetoprotein variants in second-trimester biochemical screening for trisomy 21 and 18.

To evaluate the clinical predictive value of serum alpha-fetoprotein variants (AFP-L2, AFP-L3) in combination with maternal serum prenatal screening biomarkers in predicting fetal trisomy 21 and trisomy 18. We analyze the data of singleton pregnant women at 15-20+6 weeks of 731,922 gravidas from October 2007 to September 2019. The research objects were separated into the following groups: control (n = 569), trisomy 21 (n = 116), and trisomy 18 (n = 52). The cases were diagnosed by chromosomal karyotypic analysis of amniotic fluid cells. Level of AFP-L2 and AFP-L3 were detected in maternal serum among control women and patients. Receiver operator characteristic analysis, detection rate, false positive rate, false negative rate, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio, comprehensive discriminant improvement, net weight classification improvement, decision curve analysis and Hosmer-lemeshow (H-L) test were used to investigate the predictive value of free ß-hCG, AFP, AFP-L2 and AFP-L3 on the risk models of trisomy 21, 18. There was a statistically significant difference in maternal serum AFP-L2 and AFP-L3 multiple of the median (MoM) among the trisomy 21, trisomy 18, and control groups. The AUCs of AFP-L2 and AFP-L3 for the screening trisomy 21 and trisomy 18 fetus were 0.785, 0.758 and 0.775, 0.754. According to ROC, the optimal cut-off values of AFP-L2 and AFP-L3 for predicting trisomy 21 and trisomy 18 fetuses all were 1.09 MoM and 1.30 MoM, respectively. The risk-calculation model constructed by AFP-L2 + AFP-L3 MoM manifested better efficiency than the original single-value truncation method using AFP MoM alone. Compared with different modeling methods, the AUC of trisomy 21 fetuses predicted by AFP-L2 + AFP-L3 + free ß-hCG achieved an optimal value (0.938), while the AUC of trisomy 18 fetus predicted by AFP-L2 + free ß-hCG was the best (0.991). Compared with AFP, the IDI of AFP-L2 or AFP-L3 alone increased 9.56% and 12.34%; the NRI increased 26.50% and 26.70 in predicting trisomy 21. For trisomy 18, the IDI of AFP-L2 or AFP-L3 alone declined with 8.12% and 1.52%; the NRI declined with 13.84% and 8.54%. In the combined model, the model with best detection rate, false positive rate and positive likelihood ratio was AFP-L2 + AFP-L3 + free ß-hCG, followed by AFP-L2 + free ß-hCG and AFP-L3 + free ß-hCG, and finally AFP + free ß-hCG. Maternal serum AFP-L2 and AFP-L3 in the second trimester is a good marker for screening trisomy 21 and trisomy18 with high sensitivity and specificity. The combined screening results are better than the single marker, and the efficiency of AFP-L2 + AFP-L3 + free ß-hCG is the best.

3D Quantitative Prediction of the Groundwater Potential Area-A Case Study of a Simple Geological Structure Aquifer.

The Ordos Basin is a sedimentary basin located in Inner Mongolia, China, where coal and uranium coexist. Water inrush disasters have always been one of the main disasters that threaten the safety of coal mine production, and thus, the study and division of groundwater potential regions are of great significance for the prevention of water inrush disasters and in situ leaching of sandstone-type uranium ore. A new method combining truncated Gaussian simulation and sedimentary facies control was established to predict the groundwater potential area. Taking a typical aquifer, the Zhiluo Formation, as an example, based on high-resolution sequence stratigraphy, geophysics, sedimentary geology, and geostatistical theory, the plane distribution of sand bodies was predicted. Furthermore, the relationship between rock porosity and electricity porosity was established to calculate the regional porosity. Combined with truncated Gaussian simulation and facies-controlled modeling methods, a facies-controlled heterogeneous property model was established to analyze the heterogeneous effective porosity of the aquifer in the study area. Groundwater potential areas were quantitatively evaluated by 3D modeling analysis. The results of the evaluated model were verified by actual data and provide a geological guarantee for the accurate mining of deep coal and uranium ore. A 3D distributed model of chemical elements, which is meaningful for in situ leaching uranium mining, is expected in future research.

Predicting Hypertensive Disease in the First Trimester of Pregnancy: Risk Models and Analysis of Serum D-dimer Levels Combined with Plasma Pregnancy-Associated Protein A, Free ß-Subunit of Human Chorionic Gonadotropin, and Fetal Nuchal Translucency.

We aimed to investigate the predictive ability of serum levels of D-dimer (DD) in the first trimester for the occurrence of hypertensive disorders of pregnancy (HDP). In this retrospective, case-cohort study, we measured the levels of DD, plasma pregnancy-associated protein A (PAPP-A), and free ß-subunit of human chorionic gonadotropin (free ß-hCG) and analyzed fetal nuchal translucency (NT) in 150 healthy gravidas, 126 cases of gestational hypertension (GH), 53 cases of preeclampsia (PE), and 41 cases with severe preeclampsia (SPE). Likelihood ratio models and risk models were built using single markers (DD, PAPP-A, free ß-hCG, and NT) and combinations of those markers. Analyses showed that the levels of DD multiple of the median (MoM) in the GH, PE, and SPE groups were all significantly higher than those in the control group, with significant differences between groups (χ 2 = 70.325, P < 0.001). The area under curve (AUCs) for DD in the GH, PE, and SPE groups was 0.699, 0.784, and 0.893, respectively; the positive likelihood ratio (+LR) was 1.534, 1.804, and 2.941, respectively; and the negative likelihood ratio (-LR) was 0.022, 0.081, and 0, respectively. When the cut-off values of DD for the GH, PE, and SPE groups were 0.725, 0.815, and 0.945 MoM, respectively, the corresponding sensitivities were 0.992, 0.962, and 1.000, respectively. As gestational hypertension progressed, the levels of DD tended to increase gradually. The maternal serum level of DD in the first trimester had correlative and diagnostic value for HDP. The sensitivity and specificity of maternal serum levels of DD level in the first trimester for different types of HDP were significantly different; the best sensitivity and specificity were detected in the SPE group. First trimester DD level, combined with other biochemical markers, may improve our ability to diagnose HDP.

External Quality Assessment of Maternal Serum Levels of Alpha-Fetoprotein, Free Beta-Human Chorionic Gonadotropin, and Unconjugated Estriol in Detecting Down Syndrome and Neural Tube Defects in the Second Trimester of 87 Maternal Serum Samples, Based on 105-139 Days.

BACKGROUND We aimed to insure the accuracy and reproducibility of alpha-fetoprotein (AFP), free beta-human chorionic gonadotropin (free ß-hCG), and unconjugated estriol (uE3) concentrations for the screening for trisomy 21 (T21) and neural tube defects (NTD) in the second trimester. We conducted an external quality assessment of 6 laboratories, using maternal serum specimens. MATERIAL AND METHODS Serum specimens collected from 87 women of singleton pregnancies (4 with T21, 5 with NTD, and 78 with normal fetuses) were divided into 6 equivalent-volume fractions and transported to 6 laboratories (A, B, C, D, E, and F). All laboratories used the time-resolved fluorescence analyzer and supporting reagents to measure concentrations of AFP, free ß-hCG, and uE3. The screening efficacies of T21 and NTD were compared with the certified or accredited status of the participants' quality systems. RESULTS Concentrations of AFP measured by laboratory F were low compared with those determined by the other 5 laboratories, and the differences were significant (P<0.01). There was no statistically significant difference in the free ß-hCG and uE3 concentrations measured by the 6 laboratories (P>0.05). The correlation coefficients for the 3 multiples of the median values were all >0.900. The McNemar paired chi-squared test showed the differences in the positivity and detection rates were not statistically significant (P=1.000). CONCLUSIONS AFP, free ß-hCG, and uE3 values measured by the other 5 laboratories were comparable with those of laboratory A, with good linear correlation. When used in the maternal prenatal screening of T21 and NTD, the test results met the clinical requirements.

A risk model that combines MAP, PlGF, and PAPP-A in the first trimester of pregnancy to predict hypertensive disorders of pregnancy.

Whether the first trimester maternal mean arterial pressure (MAP), placental growth factor (PlGF), and pregnancy-associated plasma protein A (PAPP-A) can predict hypertensive disorders of pregnancy (HDP) is unclear. We conducted a retrospective case-control study with the total population of 539 gravidas, of these 447 had normal pregnancy, 27 had gestational hypertension (GH), 36 had preeclampsia (PE), and 29 had preeclampsia with severe features (SPE). Prediction for HDP was determined by the area under curve (AUC). Compared to the healthy group, the multiple of the median (MoM) for MAP was increased in the study groups, while PlGF and PAPP-A were decreased. When the cutoff values for MAP, PlGF, and PAPP-A were 1.069, 0.769, and 0.673 MoM, respectively, the sensitivities for predicting HDP were 0.517, 0.446, and 0.500 and the specificities were 0.744, 0.826, and 0.769, respectively. To predict GH, the highest AUC was 0.755 (95% CI: 0.655-0.856, p < 0.001) based on MAP, PlGF, and PAPP-A. The combined PlGF and PAPP-A had the highest AUC (0.683 [95% CI: 0.584-0.782, p < 0.001] and 0.755 [95% CI: 0.682-0.829, p < 0.001]) for prediction of PE and SPE. We found that MAP, serum levels of PlGF, and PAPP-A in the first trimester pregnancy are markers that predict HDP in the third trimester. The combination of markers is far superior to single markers alone. To improve the diagnostic value, specific cutoff values should be applied to GH, PE, SPE in each condition.

Facies-Controlled Geostatistical Porosity Model for Estimation of the Groundwater Potential Area in Hongliu Coalmine, Ordos Basin, China.

Accurate and reliable evaluations of potential groundwater areas are of significance in the hydrogeological assessments of coalfields because water inrush disasters may be caused by unclear groundwater potential. A three-dimensional geological model of porosity based on deterministic modeling and a facies-controlled method are used to determine the groundwater potential of the coal measure aquifer. The modeling processes are as follows: based on the interlayer and discontinuity (faults) data extracted from boreholes and geological maps, an integrated sequence framework model is developed. Using the results of sedimentary microfacies identification and the method of deterministic modeling, a sedimentary microfacies model is successfully established. Finally, based on facies-controlled and sequential Gaussian methods, an effective porosity model is established that can predict the groundwater potential. The predicted results show that sandstones sedimented in channel, point bar, and batture environments possess high effective porosity and strong groundwater potential; however, the sandstones sedimented in interdistributary bays, flood plains, and sand sheets possess low effective porosity. Model validation was performed based on the hydrological pumping test data collected from observation boreholes, drainage water inflow data from dewatered boreholes in the tunnel around workface, and the mine water inflow in tunnels and the workfaces. The validation analysis results show that the effective porosity and sedimentary facies were correlated with the actual flux. The predicted results are consistent with the actual flux data, validating the predicted model.

Second trimester maternal serum D-dimer combined with alpha-fetoprotein and free ß-subunit of human chorionic gonadotropin predict hypertensive disorders of pregnancy: a systematic review and retrospective case-control study.

BACKGROUND: This study investigated whether maternal serum D-dimer (DD) alone or DD combined with alpha-fetoprotein (AFP) and free ß-subunit of human chorionic gonadotropin (free ß-hCG) in the second trimester could be used to predict hypertensive disorders of pregnancy (HDP). MATERIALS AND METHODS: In this retrospective case-control study, the data of gravidas patients who delivered at hospital were divided into the following groups: control (n = 136), gestational hypertension (GH, n = 126), preeclampsia (PE, n = 53), and severe preeclampsia (SPE, n = 41). Receiver operator characteristic (ROC) curves were used to evaluate the diagnostic value of maternal serum DD, AFP, and free ß-hCG levels for HDP. RESULTS: DD levels of the GH, PE, and SPE groups were significantly higher than that of the control group (P < 0.001). The order of effectiveness for models predicting HDP was as follows: DD + AFP + free ß-hCG > DD > DD + AFP > DD + free ß-hCG > AFP + free ß-hCG > AFP > free ß-hCG. For predicting different types of HDP, DD alone had the best diagnostic value for SPE, followed by PE and GH. DD alone had a sensitivity of 100% with a 0% false negative rate and had the highest positive likelihood ratio (+ LR) for SPE. DD alone in combination with AFP alone, free ß-hCG alone and AFP + free ß-hCG could reduce false positive rate and improve + LR. CONCLUSION: DD is possible the best individual predictive marker for predicting HDP. Levels of DD alone in the second trimester were positively correlated with the progression of elevated blood pressure in the third trimester, demonstrating the predicting the occurrence of HDP. The risk calculation model constructed with DD + free ß-hCG + AFP had the greatest diagnostic value for SPE.

New cut-off values for screening of trisomy 21, 18 and open neural tube defects (ONTD) during the second trimester in pregnant women with advanced maternal age.

BACKGROUND: To determine whether advanced maternal age (AMA) causes changes in the maternal serum markers of Trisomy 21, 18 and open neural tube defects (ONTD) during the second trimester of pregnancy. Our research aims to develop new cut-off values for AMA in order to reduce the need for further invasive testing. METHODS: This retrospective cohort study involved 12,739 pregnant women with AMA and 197,101 pregnant women with non-AMA. We then compared the two groups with respect to the positive rate and positive predictive value (PPV) of Trisomy 21, 18 and ONTD. Pregnant women with Trisomy 21, 18 and ONTD were diagnosed by karyotyping the amniotic fluid and by ultrasound diagnosis. RESULTS: Compared to the non-AMA group, the multiple of the median (MOM) of free beta- human chorionic gonadotropin (free ß-hCG), alpha-fetoprotein (AFP), and the risk value forTrisomy 21, were significantly higher in the AMA group (all P < 0.001). The positive rates of Trisomy 21, 18, and ONTD in the AMA group were significantly higher than those in the control group (all P < 0.001). In the AMA group, the PPVs for Trisomy 21 and other deformities were significantly higher (all P < 0.001), although the PPVs for Trisomy 18 and ONTD were similar to those of the non-AMA group. The area under the curve (AUC) values for the AMA group were higher than the non-AMA group, based on free ß-hCG MoM, AFP MoM, and the risk value of Trisomy 21. The cut-off value for the risk value of Trisomy 21 was 1/172 for the AMA, group and 1/780 for the non-AMA group. CONCLUSIONS: The positive rates for Trisomy 21, 18 and ONTD, and the PPV for Trisomy 21 and other deformities were significantly higher in the AMA group. It is essential for pregnant women with AMA to be tested using appropriate cut-off values of serum markers screening for Trisomy 21 during the second trimester of pregnancy to improve the efficacy of prenatal screening and reduce the need for further invasive testing.

Accurate Device-Free Tracking Using Inexpensive RFIDs.

Without requiring targets to carry any device, device-free-based tracking is playing an important role in many emerging applications such as smart homes, fitness tracking, intruder detection, etc. While promising, current device-free tracking systems based on inexpensive commercial devices perform well in the training environment, but poorly in other environments because of different multipath reflections. This paper introduces RDTrack, a system that leverages changes in Doppler shifts, which are not sensitive to multipath, to accurately track the target. Moreover, RDTrack identifies particular patterns for fine-grained motions such as turning, walking straightly, etc., which can achieve accurate tracking. For the purpose of achieving a fine-grained device-free tracking system, this paper builds a trajectory estimating model using HMM (Hidden Markov Model) to improve the matching accuracy and reduce the time complexity. We address several challenges including estimating the tag influenced time period, identifying moving path and reducing false positives due to multipath. We implement RDTrack with inexpensive commercial off-the-shelf RFID (Radio Frequency IDentification) hardware and extensively evaluate RDTrack in a lobby, staircase and library. Our results show that RDTrack is effective in tracking the moving target, with a low tracking error of 32 cm. This accuracy is robust for different environments, highlighting RDTrack's ability to enable future essential device-free moving-based interaction with RFID devices.

[Research on the application of mid-infrared based quantification of water in oil used by marine-borne machines].

A method that could be used to quantify the concentration of water in oil for marine-borne machine is discussed in the present paper. Water molecule has distinct absorption bands in mid-infrared section in 3773-3509 cm(-1), so it could be applied to the quantification of water in oil. An experimental sample cell was designed to accomplish the experiment for the convenience of sample preparation and mount in measurement, and it was designed to suit for FTIR spectrometer. The authors chose to prepare the sample oil by blending different amount of water into oil through titration. The spectra of oil with different water concentration were acquired and their integrals were calculated. The analysis of experimental result shows that the functional relationship between the integral of spectrum in 3773-3509 cm(-1) and the percentage of water content in oil is a quadratic curve. The relative error between the fitted curve and experimental data is at the level of 0.01%. The research work in this paper presents the possibility of quantification of water content in oil through mid-infrared and gives us an idea to design a kind of new sensor based on mid-infrared LED and PIN for measure and to warn people who monitor the abnormal variation of water content in different kind of oil used in marine-borne mechanical system.