[Changes of soil water budget in the area covered by biological soil crusts in Mu Us sandy land, China]. / æ¯›ä¹Œç´ æ²™åœ°ç”Ÿç‰©ç»“çš®è¦†ç›–åŒºåœŸå£¤æ°´åˆ†æ”¶æ”¯å˜åŒ–ç‰¹å¾.

Exploring and quantifying the impacts of biological soil crusts on soil hydrological processes and soil water budget in semi-arid ecosystems can provide a theoretical basis for vegetation restoration and reconstruction in deserts. Based on continuous observation of soil water content in different types of areas covered by biological soil crusts (e.g., algae, moss) and bare sand in the Mu Us sandy land during the growing season (May to October) from 2018 to 2020, we examined the effects of biological soil crusts on soil water budget at a depth of 0-40 cm. Results showed that algae and moss crusts significantly reduced soil water supplement below 40 cm by rainfall and increased soil water evaporation loss, compared with that under bare sand. In the relatively wet year (2018), the amount of soil water expenditure (seepage+evaporation) covered by bare sand and the various types of biological soil crusts was less than that of rainfall, resulting in net soil water income. In the relative dry years (2019 and 2020), the amount of soil water expenditure covered by dominant algae and moss crusts was higher than that of rainfall, causing net soil water deficit, but opposite for bare sand. Biological soil crusts led to the imbalance of soil water budget of 0-40 cm depth and even soil water deficit in relatively dry years, which may lead to the succession of plant communities to be dominated by shallow-rooted plants in this area.

Qualitative Evaluation of Virtual Touch Imaging Quantification: A Simple and Useful Method in the Diagnosis of Breast Lesions.

OBJECTIVE: To test the value of qualitative virtual touch imaging quantification (VTIQ) features in differentiating benign from malignant breast lesions. METHODS: From November 2016 to August 2017, 230 lesions were subjected to conventional US and virtual touch imaging quantification before biopsy. The maximum shear wave velocity (SWVmax) was measured using a standardized method. Qualitative VTIQ features, including the "stiff rim" sign and color pattern classification, were assessed according to a binary classification. The sensitivity, specificity and area under the receiver operating curve (AUC) of Breast Imaging Reporting and Data System (BI-RADS), SWVmax, qualitative VTIQ features, and combined data were compared. RESULTS: Among the 230 breast lesions, 150 were benign and 80 were malignant. Compared to the benign lesions, the malignant ones had higher SWVmax values and were more likely to show the "stiff rim" sign and VTIQ pattern 2 (P <0.001 for all). The AUC value was 0.885 for the qualitative VTIQ combination (the presence of the "stiff rim" sign and/or the display of VTIQ pattern 2), similar to that for SWVmax (P=0.472). BI-RADS combined with the qualitative VTIQ combination and with SWVmax yielded similar results, including significantly higher AUC values (P = 0.018 and 0.014, respectively), significantly higher specificities (P<0.001 for both), and nonsignificantly decreased sensitivities (P = 0.249 for both) compared to BI-RADS alone. CONCLUSION: The dual-category classification of qualitative VTIQ features according to the presence of the "stiff rim" sign and/or the classification of VTIQ pattern 2 is a simple and useful method that may be representative of quantitative VTIQ parameters in the evaluation of breast masses.

Similar Reproducibility for Strain and Shear Wave Elastography in Breast Mass Evaluation: A Prospective Study Using the Same Ultrasound System.

The objective of this study was to evaluate the inter-operator reproducibility of strain elastography (SE) and shear wave elastography (SWE) in three groups: all lesions, benign lesions and malignant lesions. Ninety-one lesions from ninety-one women were examined by SE and SWE from January 2017 to December 2017 by two radiologists. The reproducibility of elastic score, SE strain ratio and SWE Young's modulus between operators was prospectively evaluated. There was good agreement on elasticity score, with κ values of 0.711, 0.640 and 0.766. The intra-class correlation coefficients of the strain ratio, mean elastic modulus (Emean), maximum elastic modulus (Emax) and elastic modulus standard deviation (Esd) ranged from 0.723-0.876, which indicated good and excellent agreement. We concluded that both SE and SWE had good reproducibility among different operators using the same probe in the same ultrasound instrument. Strain elasticity score was more consistent among operators in malignant breast tumors. There was better agreement on strain elastic ratio and shear wave elasticity among operators in benign breast lesions.

Preoperative Axillary Ultrasound in the Selection of Patients With a Heavy Axillary Tumor Burden in Early-Stage Breast Cancer: What Leads to False-Positive Results?

OBJECTIVES: To determine whether imaging and clinicopathologic features could predict false-positive axillary ultrasound (US) results in the selection of patients with breast cancer who had a heavy axillary tumor burden (≥3 tumor-involved nodes). METHODS: Among 788 patients with histologically confirmed invasive breast cancer at Ruijin Hospital from October 2014 to September 2015, 162 patients (cT1-T2, cN0) with 167 axillae had suspicious axillary US findings. Ultrasound findings were considered suspicious for metastasis if cortical thickening of greater than 3 mm or effacement of the fatty hilum was present. The false-positive rate of suspicious axillary US results for identifying 3 or more positive lymph nodes in the final pathologic examination was calculated. Univariate and multivariate analyses were used to evaluate imaging and clinicopathologic factors related to the false-positive results. RESULTS: Axillary US showed a false-positive rate of 60.5% (101 of 167) in the patients with breast cancer and a heavy nodal burden. By logistic regression analyses, we found false-positive axillary US results more frequently in patients who had a T1 stage tumor (P = .005), an estrogen receptor/progesterone receptor-negative tumor (P < .001), solitary suspicious nodes identified on axillary US (P < .001), and a cortical thickness of the most suspicious lymph node of 3.5 mm or less (P = .015). CONCLUSIONS: Imaging and clinicopathologic features can be used to identify axillae with less than 3 metastatic nodes in patients with early-stage breast cancer who have positive axillary US results. In the post-American College of Surgeons Oncology Group Z0011 trial era, conducting a secondary evaluation either clinically or by axillary imaging before the use of a US-guided biopsy of suspicious nodes can potentially avoid the additional morbidity of axillary lymph node dissection and reduce the preoperative workload.

[Storages and distributed patterns of soil organic carbon and total nitrogen during the succession of artificial sand-binding vegetation in arid desert ecosystem].

Soil carbon pool acts as the largest one of carbon pools in the terrestrial ecosystem. The storages and distributed patterns of soil organic carbon (SOC) and total nitrogen (TN) evaluated accurately are helpful to predict the feedback between the terrestrial ecosystem and climate changes. Based on the data about bulk density, content of SOC and TN at 0-100 cm soil profile, the density of SOC and TN at the temporal (chronosequence of artificial vegetation) and spatial (vertical) distributed patterns have been estimated. The results indicated that storages of SOC and TN at 0-100 cm depth increased with the chronosequence of artificial vegetation. The storages of SOC and TN showed the same tendency with the succession time of artificial vegetation. Storages of SOC and TN significantly increased at the early stage of banding sand by artificially vegetation (< 16 a), then piled up at the mid-stage (16-25 a), and markedly increased at the late stage (> 25 a). The variation of storages mainly occurred in the 0-20 cm depth. The storages decreased with the soil vertical depth. At the early stage of banding sand, increase in storage included every depth (0-100 cm). Whereas, at the later stage, increase in storage at 0-20 cm depth was main, and increase in the 20-100 cm was inconspicuous. The accumulation of storage at the shallow soil depth was more notability with the succession of artificial vegetation. The distributed pattern of storage in SOC and TN has been confirmed in arid desert regions below 200 mm annual precipitation. This was beneficial to understand the carbon cycle and to predict the feedback relationship between desert ecosystem and climate changes.

[Transcriptional regulation of BHLHB2 induced by PML-RARα].

Objective of this study was to investigate the transcriptional regulation of BHLHB2 gene by the PML-RARα fusion protein in APL cells and reveal the pathogenesis of APL. RT-PCR was performed to detect the expression change of BHLHB2 before and after the induction of PML-RARα in PR9 cells, and its expression level after the treatment of ATRA in PR9 and APL patient derived NB4 cells. Chromatin immunoprecipitation (ChIP)-based PCR was used to analyze whether the BHLHB2 promoter could be bound by PML-RARα in vivo. A large-scale gene expression profile dataset was used to observe the expression pattern of BHLHB2 in AML. The results showed that the expression level of BHLHB2 was significantly reduced with the induction of PML-RARα and ATRA could reverse this inhibition in both PR9 and NB4 cells and increase the expression of BHLHB2. However, the expression of BHLHB2 could not be induced by ATRA in U937 cells which do not express PML-RARα. Mechanism study revealed that PML-RARα could bound to the promoter of BHLHB2 in vivo to regulate the the expression of BHLHB2. It was found that the expression of BHLHB2 was relatively lower in APL as compared with other subtypes of AML and normal bone marrow cells. It is concluded that BHLHB2 is the target of PML-RARα, and the expression of BHLHB2 is inhibited by PML-RARα through binding to its promoter in APL.

Simulation of the ligament forces affected by prosthetic alignment in a trans-tibial amputee case study.

The aims of this study were to predict and explain the patterns of ligament forces in the stump of a left trans-tibial amputee during walking, and to study the effects of the prosthetic alignment. Musculoskeletal modeling and computer simulation were combined to calculate ligament forces. The prosthesis was aligned to be in optimal position for the subject and then changed by +/-6 degrees in the sagittal plane. The results showed most ligaments bearing the maximum tension forces around both heel-strike and toe-off. The PT force was the biggest in all of the ligaments which were studied. The load patterns of ACL and PCL were opposite in the gait cycle, but the load patterns of MCL and LCL appeared similar. The above results showed that the ligament forces increased at the incorrect alignment, because the incorrect alignment could break the relative translation of the femur and tibia, and that would generate the extra ligament strains. As a result, the ligament forces increased, and the long-duration fatigue occurred more easily. This finding suggests that the proper prosthetic alignment is very important for the normal activities of the stump ligaments.

[Spatial pattern of sand-mound of Nitraria in different habitat at the southeastern fringe of the Tengger desert].

Based on the geo-statistics and quantitative ecology method, the spatial pattern of sand-mound of Nitraria was been analyzed in different habitat at the southeastern fringe of the Tengger desert in order to keep the natural mounds stability and ecological efficiency. The results showed that the different groundwater level and plant growth condition resulted in difference of Nitraria population at capacity of withstanding sand bury and the effect of sand-binding. The coverage, density and biomass of Nitraria population at the lacustrine basin lowland were significant higher than those of the alluvial fan (p < 0.01). Although the height of Nitraria population at the lacustrine basin lowland was lower than that of the alluvial fan, there was no significant difference between two habitat (p > 0.05). The height and volume of sand-mound was 1.20 m and 88.19 m3 at the lacustrine basin lowland, 1.14 m and 33.16 m3 at the alluvial fan, respectively. The size and distribution of sand-mound was significant difference at different habitat (p < 0.01). The mound of the lacustrine basin lowland has the tendency of large patch and low density, developed longer scale pattern in auto-correlated distance, and those of the alluvial fan just the reverse. The spatial heterogeneity of mound size and volume of accumulation sand in the lacustrine basin lowland can be controlled by auto-correlated factors at 1.2-84 m scale, and the random factors at under 100 m controlled the spatial heterogeneity in the alluvial fan. Especially, the size and volume of sand-mound has constant variation at under the 100 m scale in the alluvial fan, and has random spatial pattern without law.

Spatial variability of organochlorine pesticides (DDTs and HCHs) in surface soils from the alluvial region of Beijing, China.

The spatial variability in the concentrations of 1,2,3,4,5,6-hexachlorocyclohexane (HCH) and 1,1,1-trichloro-2,2-bis-(p-chlorophenyl) ethane (DDT) in surface soils was studied on the basis of the analysis of 131 soil samples collected from the surface layer (0-20 cm depth) of the alluvial region of Beijing, China. The concentrations of total HCHs (including alpha-, beta-, gamma-, and delta-isomers) and total DDTs (including p,p'-DDT, p,p'-DDD, p,p'-DDE, and o,p'-DDT) in the surface soils tested were in the range from nondetectable to 31.72 microg/kg dry soil, with a mean value of 0.91, and from nondetectable to 5910.83 microg/kg dry soil, with a mean value of 32.13, respectively. It was observed that concentrations of HCHs in all soil samples and concentrations of DDTs in 112 soil samples were much lower than the first grade (50 microg/kg) permitted in "Environment quality standard for soils in China (GB15618-1995)". This suggests that the pollution due to organochlorine pesticides was generally not significant in the farmland soils in the Beijing alluvial region. In this study, the spatial distribution and trend of HCHs and DDTs were analyzed using Geostatistical Analyst and GS+(513). Spatial distribution indicated how these pesticides had been applied in the past. Trend analysis showed that the concentrations of HCHs, DDTs, and their related metabolites followed an obvious distribution trend in the surface soils from the alluvial region of Beijing.