Visualising liver fibrosis by phase-contrast X-ray imaging in common bile duct ligated mice.

OBJECTIVES: To determine whether phase-contrast X-ray imaging can be used to visualise directly the accumulated extracellular matrix proteins associated with liver fibrosis in common bile duct ligated mice. METHODS: Twenty-six-week-old C57BL female mice were randomised into three groups. In groups 1 (n = 5) and 2 (n = 10), common bile duct ligation was conducted to produce secondary biliary cirrhosis. Mouse livers were then excised 15 (group 1) and 40 days (group 2) after the ligation of the common bile duct for imaging. In the control group, the livers of 5 mice were excised 40 days after the sham operation. Images were then acquired using the analyser crystal set at different positions of the rocking curve. RESULTS: The results show that the fibrotic septa and hepatic lobules enclosed by fibrotic septa can be visualised clearly at the whole organ level via phase-contrast X-ray imaging without any contrast agent. CONCLUSION: These results suggest that phase-contrast X-ray imaging can easily reveal the accumulated extracellular matrix proteins associated with liver fibrosis without using any contrast agent and has great potential in the study of liver fibrosis.

[The characteristics and dielectric dynamics of hydrated TiO2 in THz frequency range].

Terahertz time-domain spectroscopy (THz-TDS) was used to measure the information of water, the terahertz time-domain and frequency spectroscopy, absorbance, refractive index and the complex dielectric permittivity in the frequency range of 0.21-1 THz of various hydrated TiO2 samples with heating for different times. The result reveals that the absorbance of hydrated TiCO2 reduces with heating time increasing, and the location of the absorption peak is corresponded to the refractive index. The response of electric polarization in THz field has no clear relations with the frequency. With frequency increasing, the dielectric dissipation of hydrated TiO2 firstly decreases and then tends to be stable. The dielectric response always reduces with heating time increasing.

Distal pancreatectomy with En bloc celiac axis resection for locally advanced pancreatic body/tail cancer: A systematic review and meta-analysis.

Distal pancreatectomy with En-bloc celiac axis resection (DP-CAR) is a challenging procedure that has yielded certain clinical efficacy in the treatment of locally advanced pancreatic body/tail cancer, especially in patients with invasion of abdominal vessels. However, the clinical efficacy and safety of DP-CAR remain controversial. The study aimed to systematically review efficacy and safety of DP-CAR in the treatment of locally advanced pancreatic body/tail cancer. We systematically searched PubMed, EMBASE, Cochrane Library, and Web of Science databases from inception to 1 October 2020. Two studiers independently accomplished the study selection, data extraction, and quality assessment. Initially, of 1032 studies were searched, among which 11 high quality studies including 1072 patients were finally identified. The pooled results showed that DP-CAR versus Distal pancreatectomy (DP), the rate of R0 resection (RR = 0.76; 95%CI: 0.66 to 0.88; p = 0.0002) and 3-year survival (RR = 0.65; 95%CI: 0.43 to 0.98; p = 0.04) was lower, postoperative mortality (RR = 2.48; 95%CI: 1.02 to 6.03; p = 0.04) was higher, the operation time (MD = 104.67; 95%CI: 84.70 to 124.64; p < 0.001) and hospital stay (MD = 3.94, 95% CI 1.35 to 6.53; p = 0.003) were longer. There was no statistical difference between the DP-CAR and DP group in 1-year, 2-year survival rate (RR = 0.84; 95%CI: 0.57 to 1.23; p = 0.37) (RR = 0.70; 95%CI: 0.45 to 1.10; p = 0.12). In conclusion, compared with DP, DP-CAR has worse efficacy and prognosis survival and is more dangerous, but it can obtain better survival benefit and quality of life than palliative treatment. We suggest that DP-CAR can be carefully attempted for effective margin-negative resection. However, surgeons and patients need to know its potential perioperative risk.

Fanolike resonance due to plasmon excitation in linear chains of metal bumps.

We report the transmission anomaly in a modified slit grating, which is dressed, on the slit sidewalls, with the linear chains of metal bumps. An asymmetric lineshape, which is characteristic of the Fano resonance, has been found in a narrow frequency range of the spectrum. The effect can be attributed to the interference between nonresonant background transmission and resonant plasmonic wave excitation in the linear chains. The dispersion of chain plasmon mode has been suggested, enabling the dynamic tuning of spectral position of the Fano effect.

Optical properties of a planar metamaterial with chiral symmetry breaking.

The optical properties of a planar metamaterial with gammadion-shaped chiral symmetry breaking holes array have been investigated both theoretically and experimentally. The results indicate that the introduction of the chiral symmetry breaking causes the split of the transmission peak and exerts large influence on the optical rotation and circular dichroism. Our metamaterials might have potential applications in future design of plasmonic devices.

[Terahertz spectroscopic investigation of lanthanide-doped nano-TiO2].

Lanthanide-doped nano-TiO2 samples with different Ti/Ln (Ln = Ce, Nd, and Sm) were synthesized by sol-gel method. The samples were characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy (XPS) and terahertz time-domain spectroscopy (THz-TDS). The results indicate that Ce, Nd, and Sm ions were uniformly dispersed into the TiO2; and the infrared activities of lanthanide-deped nano-TiO2 were much stronger than Undoped nano-TiO2, the refractive index of anatase TiO2 declines with frequency increasing in the frequency range of 0.2-1.70 THz at room temperature, and it exhibits anomalous dispersion. Unique characteristic absorption peaks at 1.35 and 1.58 THz were observed from Ce-doped nano-TiO2. Compared with undoped nano-TiO2, the absorption edges of Ce-doped nano-TiO2 were red-shifted remarkably and those of Nd and Sm ions doped nano-TiO2 were blue-shifted. Sm-doped nano-TiO2 has induced the least dielectric losses in the frequency range of 0.2-1.7 THz, and the average value is 0.05.

Expression and clinical significance of paired- related homeobox 1 and Smad2 in gastric cancer.

BACKGROUND: China has a high incidence rate and low survival rate of gastric cancer. Therefore, there is a great need to further identify novel oncogenes and clinically applicable molecular targets for the diagnosis and treatment of this disease. METHODS: Expressions of PRRX1, Smad2, epithelial phenotype marker E-cadherin, and interstitial phenotype vimentin protein in a sample of 64 gastric carcinoma and adjacent nontumorous tissues were detected by immunohistochemistry. Their relationship and correlations with clinicopathological features were analyzed. RESULTS: The positive rates of PRRX1, Smad2, E-cadherin, and vimentin protein in primary tumors were 60.94% (39/64), 59.38% (38/64), 34.38%(22/64), and 64.06% (41/64), respectively. A significant correlation was found among the expression of PRRX1, Smad2, E-cadherin, and vimentin (P < 0.05). Expression of the PRRX1, Smad2, and vimentin protein in gastric cancer tissue was correlated with Borrmann classification, lymph node-positive number, the degree of differentiation, depth of tumor invasion, and serum pepsinogen I (PGI) level (P < 0.05), but not with age, sex, serum carcinoembryonic antigen, serum CA199, or PGI/PGII (P > 0.05). CONCLUSION: The positive rate of PRRX1 protein expression was positively correlated with the protein expression of Smad2 and vimentin, but negatively correlated with E-cadherin protein. PRRX1, Smad2, and vimentin proteins are associated with Borrmann type, lymph node positives, histologic grade, depth of tumor invasion, and serum PGI levels, all of which contribute to a poor prognosis for patients with gastric cancer.

[Characteristics of soil saturated hydraulic conductivity on different positions and their controlling factors of granite collapsing gullies]. / èŠ±å²—å²©å´©å²—ä¸åŒéƒ¨ä½åœŸå£¤é¥±å’Œå¯¼æ°´çŽ‡ç‰¹å¾åŠå ¶å½±å“å› ç´ .

Collapsing gully is a common phenomenon of hydraulic-gravity combined soil erosion in granite hilly area of south China. The study aimed to explore the relationship between soil hydraulics pro-perties and erosion mechanism and the intrinsic controlling factors. The active, semi-stable, and stable types of granite collapsing gullies in southeastern Guangxi were selected to examine the spatial variation of soil saturated hydraulic conductivity and identify the influencing factors. Main results were as follows: 1) Soil saturated hydraulic conductivity of collapsing gullies fluctuated on different positions, with the bottom of collapsing wall showing the minimum value, the top of colluvial deposit showing the maximum, and followed by the top of alluvial fan. 2) All the models being selected to model the soil saturated hydraulic conductivity, including Cosby, Compbell, Julià, and Hypre, performed poor. 3) Results of correlation analysis showed that soil saturated hydraulic conductivity was negatively correlated with capillary porosity and clay content, and positively correlated with non-capillary porosity and sand content. 4) Results of path analysis showed that sand content was the most influencing factor in controlling soil saturated hydraulic conductivity of collapsing gullies, followed by non-capillary porosity and soil bulk density, where sand content and non-capillary porosity exerted a positive effect and bulk density exerted a negative one. Our findings will provide theoretical basis for the mechanistic understanding and prevention of collapsing gullies erosion.

Strategy of extraction methods and reconstruction algorithms in computed tomography of diffraction enhanced imaging.

Computed tomography of diffraction enhanced imaging (DEI-CT) is a novel x-ray phase-contrast computed tomography which is applied to inspect weakly absorbing low-Z samples. Refraction-angle images which are extracted from a series of raw DEI images measured in different positions of the rocking curve of the analyser can be regarded as projections of DEI-CT. Based on them, the distribution of refractive index decrement in the sample can be reconstructed according to the principles of CT. How to combine extraction methods and reconstruction algorithms to obtain the most accurate reconstructed results is investigated in detail in this paper. Two kinds of comparison, the comparison of different extraction methods and the comparison between "two-step" algorithms and the Hilbert filtered backprojection (HFBP) algorithm, draw the conclusion that the HFBP algorithm based on the maximum refraction-angle (MRA) method may be the best combination at present. Though all current extraction methods including the MRA method are approximate methods and cannot calculate very large refraction-angle values, the HFBP algorithm based on the MRA method is able to provide quite acceptable estimations of the distribution of refractive index decrement of the sample. The conclusion is proved by the experimental results at the Beijing Synchrotron Radiation Facility.