[The efficacy of thin struct bare stents for the treatment of spontaneous isolated dissection of the superior mesenteric artery].

Objective: To examine the safety and effectiveness of thin struct bare stents for the treatment of spontaneous isolated dissection of the superior mesenteric artery (SIDSMA). Methods: The data of 32 patients admitted to First Hospital of Jiaxing (20 cases) and Jinling Hospital (12 cases) with SIDSMA from January 2016 to January 2021 were retrospectively analyzed. There were 27 males and 5 females, aging (54.8±9.4) years (range: 36 to 75 years). All patients were treated with thin struct bare stents. Controllable spring coils were used to fulfill the false lumen in 2 cases. Symptoms, vascular remodeling pattern at the SIDSMA lesion, and patency of the stents were observed during follow-up. Results: The surgical success rate was 100%. According to the length of the lesions and stents, the number of stents implanted was 1 in 17 cases, 2 in 11 cases and 3 in 4 cases. The angiography showed that blood flow in the stent was smooth and that the false lumen disappeared or weakened. The numerical rating scale for abdominal pain decreased from 6.1±1.5 (range: 4 to 10) preoperatively to 1.0 (1.0) (range: 0 to 3) 1 hour postoperatively (W=528, P<0.01). The compression rate of the true lumen of the superior mesenteric artery decreased from (92.3±6.7)% (range: 25% to 94%) preoperatively to 0.8 (1.2)% (range: 0 to 3.2%) 1 month postoperatively (W=528, P<0.01). The primary patency rate of CT angiography at 1 month postoperatively was 100%. The vascular remodeling rate was (92.3±6.7)% (range: 80% to 100%). All patients were followed for (46.3±17.0) months (range: 24 to 76 months). The cumulative patency rates in 1, 2 and 5 years were all 100%. Conclusion: The use of thin struct bare stents for SIDSMA is safety and efficacy.

Saturated hydraulic conductivity of compacted steel slag-bentonite mixtures--A potential hydraulic barrier material of landfill cover.

The feasibility of using steel slag and bentonite mixtures to construct the hydraulic barrier of a landfill cover was explored in the present study. Fine-grained steel slag (SS; particle diameter < 1 mm) and sodium-activated calcium bentonite (SACB) were used to prepare compacted specimens, and the saturated hydraulic conductivity (ks) was measured using a flexible-wall permeameter. Influential factors including SACB content (BC), SS gradation, water-washing treatment of SS and compaction water content (ωcomp) were investigated. The hydraulic conductivity results were interpreted in microscopic scale through mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM). It was found that when BC was below 10%, the ks value of the specimens prepared with well graded SS was about one order of magnitude lower than that of the specimens prepared with poorly graded SS. This was due to less macropores caused by better SS gradation. Yet, the effects of SS gradation on ks diminished as BC further increased to 15%, suggesting the dominant role of BC on ks at high BC. Water-washing treatment of SS helped reduce ks significantly to 1.2 × 10-10 m/s at BC of 10%, owing to less multivalent cations and hence lower osmotic swelling reduction caused by cations. Controlling ωcomp 1-2% wetter than the optimum water content (ωopt) also helped reduce ks significantly, owing to the reduction of macropores. Accordingly, it is suggested to use well-graded SS mixed with 10% SACB and then compact at ωcomp slightly wetter than ωopt to the degree of compaction greater than 90% in engineering practice.

MiR-122-3p regulates the osteogenic differentiation of mouse adipose-derived stem cells via Wnt/ß catenin signaling pathway.

OBJECTIVE: To explore the regulatory mechanism of micro-ribonucleic acid (miR)-122-3p in the osteogenic differentiation of mouse adipose-derived stem cells (mADSCs). MATERIALS AND METHODS: The regulatory mechanism of miR-122-3p in the osteogenic differentiation of mesenchymal stem cells was investigated through its overexpression and knockdown. RESULTS: The overexpression of miR-122-3p inhibited the osteogenic differentiation of mADSCs. On the contrary, its knockdown promoted the osteogenic differentiation of mADSCs. The further study on the molecular mechanism of miR-122-3p regulating mADSCs' osteogenic differentiation showed that the overexpression of miR-122-3p could activate the Wingless and int-1 (WNT)/ß-catenin signaling pathway, but the knockdown of miR-122-3p could repress this signaling pathway. CONCLUSIONS: MiR-122-3p influences the osteogenic differentiation of mADSCs by modulating the WNT/ß-catenin signaling pathway.

MiR-214-3p delays fracture healing in rats with osteoporotic fracture through inhibiting BMP/Smad signaling pathway.

OBJECTIVE: The purpose of this study was to explore the mechanism of micro-ribonucleic acid (miR)-214-3p in regulating fracture healing in rats with osteoporosis. MATERIALS AND METHODS: A total of 30 female Sprague-Dawley rats were selected and randomly divided into 3 groups, including group A [phosphate-buffered saline (PBS), n=10], group B (AntagomiR-NC, n=10), and group C (AntagomiR-214-3p, n=10). All rats underwent ovariectomy, and the osteoporosis rat model was verified by dual-energy X-ray absorptiometry 8 weeks after the operation. Then the osteoporotic fracture was established in rats via a second operation. From the successful modeling until the 6th week, 50 µL PBS (2 nmoL) was intraperitoneally injected in group A, an equal amount of AntagomiR-NC was injected in group B, and an equal amount of AntagomiR-214-3p was injected in group C once a week. At the 6th week, fracture healing of osteoporosis rats was evaluated. At the same time, the expression of miR-214-3p in the three groups was detected via reverse Transcription-Polymerase Chain Reaction (RT-PCR). Furthermore, the protein expressions of bone morphogenetic protein 2 (BMP2) and Smad4 in the three groups were detected via Western blotting (WB). RESULTS: After ovariectomy, the bone mineral density in each group was significantly lower than that before ovariectomy, and the differences were statistically significant (p<0.05). Imaging evaluation demonstrated that compared with group A and B, there were significantly more callus tissues in group C. Meanwhile, the fracture line healing was better and blurred, and the internal fixation had no displacement and loosening. RT-PCR results indicated that the expression level of miR-214-3p in group C was significantly lower than that of the other two groups (p<0.05). WB results showed that the protein expression levels of BMP2 and Smad4 in group C were significantly higher than those of group A and group B (p<0.05). CONCLUSIONS: MiR-214-3p delays fracture healing in rats with osteoporotic fracture by inhibiting the BMP/Smad signaling pathway.

Ventilation rates in large commercial layer hen houses with two-year continuous monitoring.

1. Ventilation controls the indoor environment and is critical for poultry production and welfare. Ventilation is also crucial for assessing aerial pollutant emissions from the poultry industry. Published ventilation data for commercial layer houses have been limited, and are mostly based on short-term studies, mainly because monitoring airflow from large numbers of fans is technically challenging. 2. A two-year continuous ventilation monitoring trial was conducted at two commercial manure belt houses (A and B), each with 250 000 layers and 88 130-cm exhaust fans. All the fans were individually monitored with fan rotational speed sensors or vibration sensors. Differential static pressures across the house walls were also measured. Three fan performance assessment methods were applied periodically to determine fan degradations. Fan models were developed to calculate house ventilations. 3. A total of 693 and 678 complete data days, each containing >16 h of valid ventilation data, were obtained in houses A and B, respectively. The two-year mean ventilation rates of houses A and B were 2·08 and 2·10 m(3) h(-1) hen(-1), corresponding to static pressures of -36·5 and -48·9 Pa, respectively. For monthly mean ventilation, the maximum rates were 4·87 and 5·01 m(3) h(-1) hen(-1) in July 2008, and the minimum were 0·59 and 0·81 m(3) h(-1) hen(-1) in February 2008, for houses A and B, respectively. 4. The two-year mean ventilation rates were similar to those from a survey in Germany and a 6-month study in Indiana, USA, but were much lower than the 8·4 and 6·2 m(3) h(-1) hen(-1) from a study in Italy. The minimum monthly mean ventilation rates were similar to the data obtained in winter in Canada, but were lower than the minimum ventilation suggested in the literature. The lower static pressure in house B required more ventilation energy input. The two houses, although identical, demonstrated differences in indoor environment controls that represented potential to increase ventilation energy efficiency, and reduce carbon footprints and operational costs.

Characteristics of ammonia and carbon dioxide releases from layer hen manure.

1. Ammonia (NH(3)) is an important gaseous pollutant generated from manure in commercial poultry farms and has been an environmental, ecological, and health concern. Poultry manure also releases carbon dioxide (CO(2)), which is a greenhouse gas and is often used as a tracer gas to calculate building ventilation. 2. A 38-d laboratory study was conducted to evaluate the characteristics of NH(3) and CO(2) releases from layer hen manure using 4 manure reactors (122 cm tall, 38 cm internal diameter), which were initially filled with 66 cm deep manure followed by weekly additions of 5 cm to simulate manure accumulation in commercial layer houses. 3. The average daily mean (ADM) NH(3) and CO(2) release fluxes for the 4 reactors during the entire study were 1615 +/- 211 microg/s.m(2) (ADM +/- 95% confidence interval) and 100 +/- 03 mg/s.m(2), respectively. The daily mean NH(3) and CO(2) releases in individual reactors varied from 352 to 6791 microg/s.m(2) and from 66 to 205 mg/s.m(2), respectively. 4. The ADM NH(3) release flux was within the range of those obtained in 4 high-rise layer houses by Liang et al. (2005, Transactions of the ASAE, 48). However, the CO(2) release flux in this study was about 10 to 13 times as high as the data reported by Liang et al. (2005). Fresh manure had greater NH(3) release potential than the manure in the reactors under continuous ventilation. Manure with higher contents of moisture, total nitrogen, and ammonium in the 4th weekly addition induced 11 times higher NH(3) and 75% higher CO(2) releases immediately after manure addition compared with pre-addition releases.

Development and validation of a dynamic mathematical model of ammonia release in pig house.

A dynamic mathematical model of Carbon-dioxide Accelerated Ammonia Release (CAAR) was developed based on the known knowledge of the chemistry of ammonia (NH3) in liquid solution, mass transfer inside liquid and across liquid-gaseous interface, and a new concept of CAAR. It calculated the NH3 concentration, release and emission at transient and steady state conditions related to a mechanically ventilated pig house. One field experimental data set was used for estimating the proportionality coefficient in the model. Another field data set was used for model validation. The ammonia concentration and emission rate calculated in the model validation were compared with the field measurement values. R2 of 0.861 and 0.947 were obtained for NH3 concentration and emission rate, respectively. In the model validation, the pH in manure surface was found to increase from 8 at initial condition to 8.85 at dynamic equilibrium due to the co-release of CO2 from the manure. This pH change accelerated the NH3 release by 6.1-fold. The model provided a quantitative description of some new understanding of the mechanism of NH3 release in the pig house and entailed suggestions of two new techniques of NH3 emission abatement: the reduction of CO2 release and the new ventilation control strategy.

A new concept of carbon dioxide accelerated ammonia release from liquid manure in pig house.

Indoor air quality in animal buildings is very important to the health of agricultural workers and animals. Carbon dioxide (CO2) and ammonia (NH3) are two of the most important pollutants in pig houses. Four tests were conduced in a mechanically ventilated pig house to study release behaviors of CO2 and NH3 from liquid manure using impulse, pulse and step ventilation inputs. The CO2 and NH3 concentrations were sampled in the exhaust chimney and measured with a CO2 monitor and a NOx analyzer, respectively. The ventilation rate was measured with a ventilation rate sensor in the chimney. A new phenomenon, characterized by a delayed dynamic response of NH3 release to the high ventilation inputs as compared with the response of CO2 release, was encountered. A new CO2 factor was identified as the cause of the delayed NH3 response. An original concept of Carbon-dioxide Accelerated Ammonia Release (CAAR) was developed. It explained that, at the initial stage of gas release induced by the high ventilation, the high release of CO2 gradually raised the pH in the surface manure. The increased pH accelerated the release of NH3. The higher release of NH3 had a negative feedback to the pH. The effects of CO2 and NH3 releases on the pH finally reached a dynamic equilibrium. The NH3 release under the dynamic equilibrium was greatly accelerated compared to that under initial conditions.