The association between early pregnancy exposure to green space and maternal glucolipid metabolism disorders: evaluation of the mediating role of serum 25-hydroxyvitamin D.

Green space and 25-hydroxyvitamin D (25(OH)D) can affect maternal and infant health, but limited studies have examined their effects on disorders of maternal glucolipid metabolism. We aimed to explore the interaction between green space, maternal serum 25(OH)D, and disorders of glucolipid metabolism in early pregnancy. A total of 2551 pregnant women were recruited from the Maanshan Maternal and Child Health Hospital birth cohort in China between 2020 and 2022. We calculated average residential greenness during early pregnancy using 250 m normalized difference vegetation index (NDVI) from satellites. Serum biomarkers (25(OH)D, total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol(HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1(ApoA1), and apolipoprotein B(ApoB)) were measured. Associations between the factors were analyzed using multiple linear regression, mediation analysis, and stratified analysis. After adjusting for potential confounders, green space exposure associated with decreased TG (- 7.8%; 95% confidence interval (CI): - 12.8, - 2.9), TC (- 7.0%; 95% CI: - 11.4, - 2.7), and LDL-C (- 8.4%; 95% CI: - 12.9, - 3.9), ApoB (- 2.0%; 95% CI: - 3.0, - 1.0) and increased HDL-C (2.7%; 95% CI: 1.5, 3.8) and ApoA1 (5.1%; 95% CI: 3.9, 6.3) for each IQR increase in NDVI. A comparable link was found between maternal serum 25(OH)D and indicators of glucolipid metabolism (P < 0.05). In addition, mediation analysis showed that the association between green space exposure and maternal glucolipid metabolic index was mediated by serum 25(OH)D at 6.37%. In stratified analyses, a considerable association between 25(OH)D and glucolipid metabolic index (except TG) was observed only at higher green space exposures. This study confirms that high levels of green space exposure in early pregnancy and vitamin D are associated with a reduced risk of glucolipid metabolism disorders and suggests that green space may favor glucolipid metabolism by increasing vitamin D levels, particularly at high NDVI values.

Application of Calcium-Based Nanomaterials in Art Sculpture Reinforcement Technology.

In order to solve the problem of the reinforcement effect of art sculpture, the author proposes the application of a calcium-based nanomaterial in the reinforcement process of art sculpture. This application mainly passes the unconfined compression test, direct shear test, penetration resistance test, and disintegration test, and an in-depth evaluation of the reinforcement effect of different calcium-based reinforcement agents on the site soil was carried out from the perspective of mechanical strength and water stability. The results showed the following: Compared with the untreated samples, the unconfined compressive strength of the samples treated with nano-calcium oxide and nano-calcium hydroxide increased by 13.5% and 25.9%, respectively, and the cohesion increased by 69.8% and 97.7%. Conclusion. Calcium-based nanomaterials fill in the pores between soil particles to support the soil particles, which greatly improves the mechanical strength and water stability of the specimen.

A Time-Walk Correction Method for PET Detectors Based on Leading Edge Discriminators.

The leading edge timing pick-off technique is the simplest timing extraction method for PET detectors. Due to the inherent time-walk of the leading edge technique, corrections should be made to improve timing resolution, especially for time-of-flight PET. Time-walk correction can be done by utilizing the relationship between the threshold crossing time and the event energy on an event by event basis. In this paper, a time-walk correction method is proposed and evaluated using timing information from two identical detectors both using leading edge discriminators. This differs from other techniques that use an external dedicated reference detector, such as a fast PMT-based detector using constant fraction techniques to pick-off timing information. In our proposed method, one detector was used as reference detector to correct the time-walk of the other detector. Time-walk in the reference detector was minimized by using events within a small energy window (508.5 - 513.5 keV). To validate this method, a coincidence detector pair was assembled using two SensL MicroFB SiPMs and two 2.5 mm × 2.5 mm × 20 mm polished LYSO crystals. Coincidence timing resolutions using different time pick-off techniques were obtained at a bias voltage of 27.5 V and a fixed temperature of 20 °C. The coincidence timing resolution without time-walk correction were 389.0 ± 12.0 ps (425 -650 keV energy window) and 670.2 ± 16.2 ps (250-750 keV energy window). The timing resolution with time-walk correction improved to 367.3 ± 0.5 ps (425 - 650 keV) and 413.7 ± 0.9 ps (250 - 750 keV). For comparison, timing resolutions were 442.8 ± 12.8 ps (425 - 650 keV) and 476.0 ± 13.0 ps (250 - 750 keV) using constant fraction techniques, and 367.3 ± 0.4 ps (425 - 650 keV) and 413.4 ± 0.9 ps (250 - 750 keV) using a reference detector based on the constant fraction technique. These results show that the proposed leading edge based time-walk correction method works well. Timing resolution obtained using this method was equivalent to that obtained using a reference detector and was better than that obtained using constant fraction discriminators.

Performance Comparison of Different Readouts for Position-Sensitive Solid-State Photomultiplier Arrays.

A thorough comparison of five different readouts for reading out a 2 × 2 array of 5 mm × 5 mm position-sensitive solid-state photomultipliers (PS-SSPM) was undertaken. The five readouts include reading out the 20 signals (16 position and 4 timing) individually, two signal multiplexing readouts, and two position decoding readouts. Flood histogram quality, signal-to-noise ratio (SNR) and energy resolution were compared at different bias voltage (27.0 V to 32.0 V, at 0.5 V intervals) and at a fixed temperature of 0 °C by coupling a 6 × 6 array of 1.3 mm × 1.3 mm × 20 mm polished LSO crystals to the center of the PS-SSPM array. The timing resolution was measured at a bias voltage of 31.0 V (optimal bias voltage in terms of flood histogram quality). The best flood histogram quality value and signal-to-noise were 7.3 ± 1.6 and 33.5 ± 3.1, respectively, and were obtained by shaping and digitizing the 16 position signals individually. The capacitive charge-division readout is the simplest readout among the five evaluated but still resulted in good performance with a flood histogram quality value of 3.3 ± 0.4 and a SNR of 18.3 ± 1.3. The average energy resolution and the average timing resolution were 15.2 ± 1.2 % and 8.4 ± 1.6 ns for individual signal readout and 15.9 ± 1.2 % and 8.8 ± 1.3 ns by using the capacitive charge-division readout method. These studies show that for an ultra-high spatial resolution applications using the 2 × 2 PS-SSPM array, reading out the 20 signals individually is necessary; whilst the capacitive charge-division readout is a cost-effective readout for less demanding applications.

Characterization of Large-Area SiPM Array for PET Applications.

The performance of an 8 × 8 array of 6.0 × 6.0 mm2 (active area) SiPMs was evaluated for PET applications using crystal arrays with different pitch sizes (3.4 mm, 1.5 mm, 1.35 mm and 1.2 mm) and custom designed five-channel front-end readout electronics (four channels for position information and one channel for timing information). The total area of this SiPM array is 57.4 × 57.4 mm2, and the pitch size is 7.2 mm. It was fabricated using enhanced blue sensitivity SiPMs (MicroFB-60035-SMT) with peak spectral sensitivity at 420 nm. The performance of the SiPM array was characterized by measuring flood histogram decoding quality, energy resolution, timing resolution and saturation at several bias voltages (from 25.0 V to 30.0 V in 0.5 V intervals) and two different temperatures (5 °C and 20 °C). Results show that the best flood histogram was obtained at a bias voltage of 28.0 V and 5 °C and an array of polished LSO crystals with a pitch as small as 1.2 mm can be resolved. No saturation was observed up to a bias voltage of 29.5 V during the experiments, due to adequate light sharing between SiPMs. Energy resolution and timing resolution at 5 °C ranged from 12.7 ± 0.8% to 14.6 ± 1.4 % and 1.58 ± 0.13 ns to 2.50 ± 0.44 ns, for crystal array pitch sizes of 3.4 mm and 1.2 mm respectively. Superior flood histogram quality, energy resolution and timing resolution were obtained with larger crystal array pitch sizes and at lower temperature. Based on our findings, we conclude that this large-area SiPM array can serve as a suitable photodetector for high-resolution small-animal PET or dedicated human brain PET scanners.

A Prototype High-Resolution Small-Animal PET Scanner Dedicated to Mouse Brain Imaging.

UNLABELLED: We developed a prototype small-animal PET scanner based on depth-encoding detectors using dual-ended readout of small scintillator elements to produce high and uniform spatial resolution suitable for imaging the mouse brain. METHODS: The scanner consists of 16 tapered dual-ended-readout detectors arranged in a 61-mm-diameter ring. The axial field of view (FOV) is 7 mm, and the transaxial FOV is 30 mm. The scintillator arrays consist of 14 × 14 lutetium oxyorthosilicate elements, with a crystal size of 0.43 × 0.43 mm at the front end and 0.80 × 0.43 mm at the back end, and the crystal elements are 13 mm long. The arrays are read out by 8 × 8 mm and 13 × 8 mm position-sensitive avalanche photodiodes (PSAPDs) placed at opposite ends of the array. Standard nuclear-instrumentation-module electronics and a custom-designed multiplexer are used for signal processing. RESULTS: The detector performance was measured, and all but the crystals at the very edge could be clearly resolved. The average intrinsic spatial resolution in the axial direction was 0.61 mm. A depth-of-interaction resolution of 1.7 mm was achieved. The sensitivity of the scanner at the center of the FOV was 1.02% for a lower energy threshold of 150 keV and 0.68% for a lower energy threshold of 250 keV. The spatial resolution within a FOV that can accommodate the entire mouse brain was approximately 0.6 mm using a 3-dimensional maximum-likelihood expectation maximization reconstruction. Images of a hot-rod microphantom showed that rods with a diameter of as low as 0.5 mm could be resolved. The first in vivo studies were performed using (18)F-fluoride and confirmed that a 0.6-mm resolution can be achieved in the mouse head in vivo. Brain imaging studies with (18)F-FDG were also performed. CONCLUSION: We developed a prototype PET scanner that can achieve a spatial resolution approaching the physical limits of a small-bore PET scanner set by positron range and detector interaction. We plan to add more detector rings to extend the axial FOV of the scanner and increase sensitivity.

Evaluation of Matrix9 silicon photomultiplier array for small-animal PET.

PURPOSE: The MatrixSL-9-30035-OEM (Matrix9) from SensL is a large-area silicon photomultiplier (SiPM) photodetector module consisting of a 3 × 3 array of 4 × 4 element SiPM arrays (total of 144 SiPM pixels) and incorporates SensL's front-end electronics board and coincidence board. Each SiPM pixel measures 3.16 × 3.16 mm(2) and the total size of the detector head is 47.8 × 46.3 mm(2). Using 8 × 8 polished LSO/LYSO arrays (pitch 1.5 mm) the performance of this detector system (SiPM array and readout electronics) was evaluated with a view for its eventual use in small-animal positron emission tomography (PET). METHODS: Measurements of noise, signal, signal-to-noise ratio, energy resolution, flood histogram quality, timing resolution, and array trigger error were obtained at different bias voltages (28.0-32.5 V in 0.5 V intervals) and at different temperatures (5 °C-25 °C in 5 °C degree steps) to find the optimal operating conditions. RESULTS: The best measured signal-to-noise ratio and flood histogram quality for 511 keV gamma photons were obtained at a bias voltage of 30.0 V and a temperature of 5 °C. The energy resolution and timing resolution under these conditions were 14.2% ± 0.1% and 4.2 ± 0.1 ns, respectively. The flood histograms show that all the crystals in the 1.5 mm pitch LSO array can be clearly identified and that smaller crystal pitches can also be resolved. Flood histogram quality was also calculated using different center of gravity based positioning algorithms. Improved and more robust results were achieved using the local 9 pixels for positioning along with an energy offset calibration. To evaluate the front-end detector readout, and multiplexing efficiency, an array trigger error metric is introduced and measured at different lower energy thresholds. Using a lower energy threshold greater than 150 keV effectively eliminates any mispositioning between SiPM arrays. CONCLUSIONS: In summary, the Matrix9 detector system can resolve high-resolution scintillator arrays common in small-animal PET with adequate energy resolution and timing resolution over a large detector area. The modular design of the Matrix9 detector allows it to be used as a building block for simple, low channel-count, yet high performance, small animal PET or PET/MRI systems.

X-ray luminescence optical tomography imaging: experimental studies.

We present a hybrid imaging modality, x-ray luminescence optical tomography (XLOT), in which collimated x-ray beams are used to excite phosphor-based contrast agents. Images are reconstructed from the optical signals, using the known x-ray beam location and spatial extent as priors. We demonstrate XLOT using phantom experiments with deep targets and show that the reconstructed signal varies by <12% when the depth changes from 4.2 to 7.7 mm. For simple source distributions, we find as few as two orthogonal projection measurements are sufficient for XLOT reconstruction.

A Simple Capacitive Charge-Division Readout for Position-Sensitive Solid-State Photomultiplier Arrays.

A capacitive charge-division readout method for reading out a 2 × 2 array of 5 mm × 5 mm position-sensitive solid-state photomultipliers (PS-SSPM) was designed and evaluated. Using this analog multiplexing method, the 20 signals (16 position, 4 timing) from the PS-SSPM array are reduced to 5 signals (4 position, 1 timing), allowing the PS-SSPM array to be treated as an individual large-area PS-SSPM module. A global positioning approach can now be used, instead of individual positioning for each PS-SSPM in the array, ensuring that the entire light signal is utilized. The signal-to-noise ratio (SNR) and flood histogram quality at different bias voltages (27.5 V to 32.0 V at 0.5 V intervals) and a fixed temperature of 0 °C were evaluated by coupling a 6 × 6 array of 1.3 mm × 1.3 mm × 20 mm polished LSO crystals to the center of the PS-SSPM array. The timing resolution was measured at a fixed bias voltage of 31.0 V and a fixed temperature of 0 °C. All the measurements were evaluated and compared using capacitors with different values and tolerances. Capacitor values ranged from 0.051 nf to 10 nf, and the capacitance tolerance ranged from 1% to 20%. The results show that better performance was achieved using capacitors with smaller values and better capacitance tolerance. Using 0.2 nf capacitors, the SNR, energy resolution and timing resolution were 24.3, 18.2% and 8.8 ns at a bias voltage 31.0 V, respectively. The flood histogram quality was also evaluated by using a 10 × 10 array of 1 mm × 1 mm × 10 mm polished LSO crystals and a 10 × 10 array of 0.7 mm × 0.7 mm × 20 mm unpolished LSO crystals to determine the smallest crystal size resolvable. These studies showed that the high spatial resolution of the PS-SSPM was preserved allowing for 0.7 mm crystals to be identified. These results show that the capacitive charge-division analog signal processing method can significantly reduce the number of electronic channels, from 20 to 5, while retaining the excellent performance of the detector.

The effects of seed size on hybrids formed between oilseed rape (Brassica napus) and wild brown mustard (B. juncea).

BACKGROUND: Seed size has significant implications in ecology, because of its effects on plant fitness. The hybrid seeds that result from crosses between crops and their wild relatives are often small, and the consequences of this have been poorly investigated. Here we report on plant performance of hybrid and its parental transgenic oilseed rape (Brassica napus) and wild B. juncea, all grown from seeds sorted into three seed-size categories. METHODOLOGY/PRINCIPAL FINDINGS: Three seed-size categories were sorted by seed diameter for transgenic B. napus, wild B. juncea and their transgenic and non-transgenic hybrids. The seeds were sown in a field at various plant densities. Globally, small-seeded plants had delayed flowering, lower biomass, fewer flowers and seeds, and a lower thousand-seed weight. The seed-size effect varied among plant types but was not affected by plant density. There was no negative effect of seed size in hybrids, but it was correlated with reduced growth for both parents. CONCLUSIONS: Our results imply that the risk of further gene flow would probably not be mitigated by the small size of transgenic hybrid seeds. No fitness cost was detected to be associated with the Bt-transgene in this study.

The detection of EBP50 expression using quantum dot immunohistochemistry in pancreatic cancer tissue and down-regulated EBP50 effect on PC-2 cells.

Ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) is a putative tumor suppressor that is correlated with many human cancers. However, the function of EBP50 in pancreatic cancer (PC) has not been described. In this paper, the EBP50 expression level in PC tissues was characterized. In vitro, the effects of EBP50 down-regulation by siRNA in PC-2 and MiaPaCa-2 cells were evaluated. In addition, possible mechanisms that mediate the influence of EBP50 were examined. Our results show that the EBP50 expression pattern changes during transformation as there is a loss of the normal apical membrane distribution and an ectopic cytoplasmic over-expression of EBP50; furthermore, the EBP50 expression level is subsequently decreased during malignant progression. Down-regulation of EBP50 promoted cancer cell proliferation, increased the colony-forming ability of cells and accelerated the G1-to-S progression. Additionally, the loss of EBP50 accentuated ß-catenin activity, increased cyclin E and phosphorylated Rb expression, and attenuated p27 expression compared to control cells. Our results suggest that EBP50 may function as a potential tumor suppressor.

Application of Trichoderma harzianum SQR-T037 bio-organic fertiliser significantly controls Fusarium wilt and affects the microbial communities of continuously cropped soil of cucumber.

BACKGROUND: The reduction in diversity of the soil microbial community causes the disorder of continuous cropping. The aim of this study was to determine the effects of applying Trichoderma harzianum SQR-T037 bio-organic fertiliser (BIO) on the microbial community in continuously cropped cucumber soil. Four treatments were set: (1) control, where neither seedling nursery soil (N) nor transplanted soil (T) was amended with BIO; (2) N treatment, where nursery soil was amended with BIO (1% w/w) but transplanted soil was not; (3) N + T treatment, where BIO was added to both nursery soil (1% w/w) and transplanted soil (0.5% w/w); (4) uncropped soil, where soil was left uncropped consistently. RESULTS: A disease index of 72.2% was found for the control treatment, while the N and N + T treatments had disease indices of only 25 and 15% respectively. Analysis of the denaturing gradient gel electrophoresis (DGGE) profiles showed that the bacterial communities of the N and N + T treatments were similar to those of the uncropped soil but distinct from those of the control soil. The fungal communities of the N and N + T treatments differed from those of both the uncropped soil and the control. CONCLUSION: Addition of BIO to both the nursery soil and the transplanted soil can diversify the microbial community in continuously cropped cucumber soil and thus effectively control Fusarium wilt of cucumber plants.

Fitness and maternal effects in hybrids formed between transgenic oilseed rape (Brassica napus L.) and wild brown mustard [B. juncea (L.) Czern et Coss.] in the field.

BACKGROUND: Gene flow between crops and weedy relatives depends on the survivorship and reproduction of early-generation hybrids in a field environment. The primary aim of this study was to compare the fitness of transgenic crop x wild hybrids with their parental types and a non-transgenic crop type in the field under enhanced temperature and humidity. RESULTS: Transgenic insect-resistant oilseed rape (Brassica napus L.), wild brown mustard [B. juncea (L.) Czern et Coss.], their hybrids and non-transgenic B. napus were grown in such a way as to mimic field conditions after harvest under which volunteer plants might appear in agricultural settings. Factor analysis revealed that vegetative growth characteristics explained most of the observed differences among plant types. Wild brown mustard had the highest fitness during its entire life history. Hybrids had intermediate composite fitness and lowest reproductive fitness. The hybrid and the wild weed shared similar vegetative growth characteristics and seed dormancy in their respective progenies. CONCLUSION: These data indicate that there might be enhanced persistence of the transgene in warmer climates. The absence of fitness cost of the transgenes might allow transgenes to persist in ecosystems. These data will contribute to risk assessments of transgene persistence and weed management against the backdrop of global climate change.