Ammonia energy fraction effect on the combustion and reduced NOX emission of ammonia/diesel dual fuel.

With stringent regulations of internal combustion engine on reducing CO2 emission, ammonia has been used as an alternative fuel. Investigating how engine-related performance is affected by partial ammonia replacement of diesel fuel is essential for understanding the combustion. Therefore, in this study, a three-dimensional numerical simulation model is developed for the burning of two fuels of diesel and ammonia based on relevant parameters (i.e., compression ratio, load, ammonia energy fraction, etc.) in a lab-made diesel engine. The consequences of load and compression proportion on combustion and pollutant emissions are investigated for ammonia energy fractions between 50% and 90%. When the ammonia portion rises, the increased ammonia equivalent ratio causes ammonia to move away from the dilute combustion boundary and accelerates the combustion rate of ammonia. An increase in compression ratio significantly increases the specified thermal performance and combustion efficacy. When the compression ratio is 16, as the ammonia energy fractions increases, due to the increase in the proportion of ammonia, that is, the proportion of nitrogen atoms increases, more NOx is generated during the combustion process. When the ammonia substitution rate is 90%, as the compression ratio increases, the cylinder pressure and temperature increase. The combustion efficiency of ammonia increases, generating more NOx and NOx emissions can reach 0.66 mg/m3. At a compression ratio of 18, the NOx emissions can reach 1.59 mg/m3. However, under medium and low load conditions, as the ammonia fraction increases, the total energy of fuel decreases, and the combustion efficiency of ammonia decreases, resulting in a decrease in the heat released during combustion and a decrease in NOx emissions. When the ammonia substitution rate is 90% and the load is 25%, NOx emissions reach 0.1 mg/m3. This research provides theoretical suggestions for the profitable and use ammonia fuel in internal combustion engines in a clean manner.

[The Role and Mechanism of MiR-451 in Multidrug Resistance of Leukemia Cell Line K562/A02].

OBJECTIVE: To detect the differential expressions of miR-451, ABCB1 and ABCC2 in drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, and explore the regulatory relationship between miR-451 and the expressions of ABCB1 and ABCC2 , and the mechanism of miR-451 involved in drug resistance in leukemia. METHODS: CCK-8 assay was used to detect the drug resistance of K562/A02 and K562 cells. Quantitative Real-time PCR (qRT-PCR) was used to verify the differential expressions of miR-451 in K562 and K562/A02 cells. MiR-451 mimic and negative control (miR-NC), miR-451 inhibitor and negative control (miR-inNC) were transfected into K562 and K562/A02 cells respectively, then qRT-PCR and Western blot were used to detect the expression levels of mRNA and protein of ABCB1 and ABCC2 in K562 and K562/A02 cells and the transfected groups. RESULTS: The drug resistance of K562/A02 cells to adriamycin was 177 times higher than that of its parent cell line K562. Compared with K562 cells, the expression of miR-451 in K562/A02 cells was significantly higher (P <0.001), and the mRNA and protein expression levels of ABCB1 and ABCC2 in K562/A02 cells were significantly higher than those in K562 cells (P <0.001). After transfected with miR-451 inhibitor, the expression of miR-451 was significantly down-regulated in K562/A02 cells (P <0.001), the sensitivity to chemotherapy drugs was significantly enhanced (P <0.05), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly decreased (P <0.01). After transfected with miR-451 mimic, the expression of miR-451 was significantly upregulated in K562 cells (P <0.001), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly increased (P <0.01). CONCLUSION: There are significant differences in the expressions of miR-451, ABCB1 and ABCC2 between the drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, which suggests that miR-451 may affect the drug resistance of leukemia cells by regulating the expression of ABCB1 and ABCC2.

The Role and Mechanism of MiR-451 in Multidrug Resistance of Leukemia Cell Line K562/A02 / 中国实验血液学杂志

OBJECTIVE@#To detect the differential expressions of miR-451, ABCB1 and ABCC2 in drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, and explore the regulatory relationship between miR-451 and the expressions of ABCB1 and ABCC2 , and the mechanism of miR-451 involved in drug resistance in leukemia.@*METHODS@#CCK-8 assay was used to detect the drug resistance of K562/A02 and K562 cells. Quantitative Real-time PCR (qRT-PCR) was used to verify the differential expressions of miR-451 in K562 and K562/A02 cells. MiR-451 mimic and negative control (miR-NC), miR-451 inhibitor and negative control (miR-inNC) were transfected into K562 and K562/A02 cells respectively, then qRT-PCR and Western blot were used to detect the expression levels of mRNA and protein of ABCB1 and ABCC2 in K562 and K562/A02 cells and the transfected groups.@*RESULTS@#The drug resistance of K562/A02 cells to adriamycin was 177 times higher than that of its parent cell line K562. Compared with K562 cells, the expression of miR-451 in K562/A02 cells was significantly higher (P <0.001), and the mRNA and protein expression levels of ABCB1 and ABCC2 in K562/A02 cells were significantly higher than those in K562 cells (P <0.001). After transfected with miR-451 inhibitor, the expression of miR-451 was significantly down-regulated in K562/A02 cells (P <0.001), the sensitivity to chemotherapy drugs was significantly enhanced (P <0.05), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly decreased (P <0.01). After transfected with miR-451 mimic, the expression of miR-451 was significantly upregulated in K562 cells (P <0.001), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly increased (P <0.01).@*CONCLUSION@#There are significant differences in the expressions of miR-451, ABCB1 and ABCC2 between the drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, which suggests that miR-451 may affect the drug resistance of leukemia cells by regulating the expression of ABCB1 and ABCC2.

Real-time in vivo distal margin selection using confocal laser endomicroscopy in transanal total mesorectal excision for rectal cancer.

BACKGROUND: Transanal total mesorectal excision (TaTME) allows patients with ultralow rectal cancer to be treated with sphincter-saving surgery. However, accurate delineation of the distal resection margin (DRM), which is essential to achieve R0 resection for low rectal cancer in TaTME, is technically demanding. AIM: To assess the feasibility of optical biopsy using probe-based confocal laser endomicroscopy (pCLE) to select the DRM during TaTME for low rectal cancer. METHODS: A total of 43 consecutive patients who were diagnosed with low rectal cancer and scheduled for TaTME were prospectively enrolled from January 2019 to January 2021. pCLE was used to determine the distal edge of the tumor as well as the DRM during surgery. The final pathological report was used as the gold standard. The diagnostic accuracy of pCLE examination was calculated. RESULTS: A total of 86 pCLE videos of 43 patients were included in the analyses. The sensitivity, specificity and accuracy of real-time pCLE examination were 90.00% [95% confidence interval (CI): 76.34%-97.21%], 86.96% (95%CI: 73.74%-95.06%) and 88.37% (95%CI: 79.65%-94.28%), respectively. The accuracy of blinded pCLE reinterpretation was 86.05% (95%CI: 76.89%-92.58%). Furthermore, our results show satisfactory interobserver agreement (κ = 0.767, standard error = 0.069) for the detection of cancer tissue by pCLE. There were no positive DRMs (≤ 1 mm) in this study. The median DRM was 7 mm [interquartile range (IQR) = 5-10 mm]. The median Wexner score was 5 (IQR = 3-6) at 6 mo after stoma closure. CONCLUSION: Real-time in vivo pCLE examination is feasible and safe for selecting the DRM during TaTME for low rectal cancer (clinical trial registration number: NCT04016948).

Preliminary prediction of the control reproduction number of COVID-19 in Shaanxi Province, China.

OBJECTIVES: Firstly, according to the characteristics of COVID-19 epidemic and the control measures of the government of Shaanxi Province, a general population epidemic model is established. Then, the control reproduction number of general population epidemic model is obtained. Based on the epidemic model of general population, the epidemic model of general population and college population is further established, and the control reproduction number is also obtained. METHODS: For the established epidemic model, firstly, the expression of the control reproduction number is obtained by using the next generation matrix. Secondly, the real-time reported data of COVID-19 in Shaanxi Province is used to fit the epidemic model, and the parameters in the model are estimated by least square method and MCMC. Thirdly, the Latin hypercube sampling method and partial rank correlation coefficient (PRCC) are adopted to analyze the sensitivity of the model. CONCLUSIONS: The control reproduction number remained at 3 from January 23 to January 31, then gradually decreased from 3 to slightly greater than 0.2 by using the real-time reports on the number of COVID-19 infected cases from Health Committee of Shaanxi Province in China. In order to further control the spread of the epidemic, the following measures can be taken: (i) reducing infection by wearing masks, paying attention to personal hygiene and limiting travel; (ii) improving isolation of suspected patients and treatment of symptomatic individuals. In particular, the epidemic model of the college population and the general population is established, and the control reproduction number is given, which will provide theoretical basis for the prevention and control of the epidemic in the colleges.

The Role of B and T Lymphocyte Attenuator in Immune Regulation and Immune Related Diseases / 中国生物化学与分子生物学报

B / T lymphuocyte attenuator (BTLA) is one of the important checkpoint molecules in immune regulation. BTLA belongs to the CD28 superfamily, and its protein structure is similar to programmed cell death-1 (PD-1) and cytotoxic T lymphocyte associated antigen-4 (CTLA-4). BTLA is mainly expressed in B and T cells, and has also been found in some innate immune cells such as dendritic cells and monocytes. To date, the herpesvirus entry mediator (HVEM) is the only ligand for BTLA found in human cells. HVEM belongs to the Tumor necrosis factor receptor (TNFR) superfamily, and its interaction with BTLA directly connects CD28 and TNFR families. The binding of BTLA with HVEM often mediates immunosuppressive effects and plays an important role in maintaining immune tolerance. However, recent studies have found that the BTLA / HVEM pathway not only provides negative regulatory signals, but also promotes the survival of T cells. This bidirectional signaling system renders BTLA-mediated immune regulation more sophisticated and complex. Growing evidence has shown that BTLA is involved in T cells, B cells and dendritic cell-mediated immune regulation, and therefore plays an important role in a variety of immune related diseases, such as inflammation, tumor, infectious diseases and autoimmune diseases. Based on the latest research progress at home and abroad, this paper reviews the role of BTLA in immune regulation and immune related diseases.

Clinical features and prognosis of patients with acute ST-segment elevation myocardial infarction comorbid with diabetes mellitus / 中国介入心脏病学杂志

Objective To investigate the clinical features of patients with acute ST-segment elevation myocardial infarction (STEMI) comorbid with diabetes mellitus (DM) and to analyze the prognosis within 12 months after primary percutaneous coronary intervention (pre-PCI). Methods A total of 375 STEMI patients were divided into the diabetes group (n=140) and the normal blood glucose group(n=235) according to whether they met the diagnostic criteria of DH. The clinical data,characteristics of coronary artery lesions,type of stent implant,rate of coronary slow flow or no-reflow after pre-PCI, and the prognosis within 12 months after PCI of the two groups were investigated.Results Patient in the diabetes group presented with higher mean age ,higher comorbid rates of hypertension , hyperlipidemia and heart function of Killip class Ш and above than patients in the normal blood glucose group (all P<0.05). patients in the diabetes group had higher rates of slow reflow /no-reflow after PCI(12.9% vs.5.5%,P=0.013),higher percentages of 3-ressel disease(40.7% vs. 28.9%,P=0.019)and lef t main lesions(13.6% vs. 7.2%,P=0.044). The in-hospital mortality rates(6.4% vs.1.7%,P=0.020),revascularization rates within 12 months(7.9% vs.0.9%,P=0.001)and incidence of heart failure(7.9% vs. 2.6%,P=0.017)were all higher in the diabetes group. Conclusions STEMI patients comorbid with DM were relatively older, had higher comorbidities of hypertension,hyperlipidemia, three-vessel disease, left main coronary lesions and higher mortality during hospitalization. No significant increase in cardiac death and recurrent myocardial infarction were deserved during the follow-up period. These patients may benefit more from early intervention.

Click modification of helical amylose by poly(l-lysine) dendrons for non-viral gene delivery.

Although amylose as a naturally-occurring helical polysaccharide has been widely used for biomedical applications, few studies have dealt with its chemical modification for non-viral gene delivery. In this work, the click modification of amylose by poly(l-lysine) dendrons was carried out and then characterized by Fourier transform infrared spectroscopy, wide-angle X-ray diffraction and elemental analyses. Such a modified polysaccharide exhibited excellent ability to condense plasmid pMSCV-GFP-PARK2 into compact and spherical nanoparticles. Moreover, it displayed much lower cytotoxicity when compared to branched polyethylenimine (bPEI, 25kDa), a commercially available gene vector. Similar to bPEI, it had a dose-dependent gene transfection activity in human embryonic kidney 293T cells, as observed by confocal laser scanning microscopy and flow cytometry. At each optimized N/P ratio, the percentage of transfected cells by this modified polysaccharide was found to be comparable to that by bPEI. Western blot and cell apoptosis analyses confirmed its effectiveness for the delivery of plasmid pMSCV-GFP-PARK2 to 293T cells.

[Soil N/P ratio distribution characteristics of alpine grassland ecosystem in Qinghai-Tibet Plateau].

The distribution characteristics of soil N/P ratio in alpine grassland ecosystem of Qinghai-Tibet Plateau were surveyed by field investigation and laboratory analysis. Horizontally, soil N/ P ratio was generally higher in west and lower in east in a manner of staggered patch distribution, with higher N/P ratios mainly centralized in the hinterland of northern part of Tibet Plateau and in the lake basin area of the northern foot of Himalayas. Significant differences in soil N/P ratio were observed among grassland types and natural transects. Vertically, the distribution of N/P ratio along the soil profile from aboveground to underground among different grass types could be categorized into five patterns, including low-high-low-high, low-high-low, low-high, high-low-high-low, and high-low-high. The N/P ratio showed a significant positive correlation with soil bulk density at 0-20 cm depth, soil water content at 20-30 cm depth, contents of soil available K and total nitrogen, respectively. However, it showed significant negative correlation with soil bulk density at 20-30 cm depth, contents of soil available P and total P, respectively.

Experimental study on cardiac pathological change in rats fed with corn and bean puree of Keshan disease area / 中国地方病学杂志

Objective To investigate the myocardial damage in rats fed with corn from Keshan disease area added with bean puree. Methods Male Wistar rats were randomly divided into 3 groups according to their body weights, and fed with corn, corn from Keshan disease area added with bean puree, corn from non-endemic area. The GSH-Px activity of vena cardalis blood was examined in 1 and 3 months, rats were sacrificed after being fed for 6 months to examine the heart changes with HE stain. Results The three groups of GSH-Px activity were different in 1 and 3 months respectively(F=23.60,72.46, all P<0.01); GSH-Px activity was (181.58±22.15), (44.76±28.59)U/L in rats fed with corn, was (195.03±17.66), (30.38±3.35)U/L in those fed with corn added with bean puree from Keshan disease area, lower than the group fed with corn of non-endemic area[(340.90±95.42), (125.17±13.64)U/L, all P < 0.01]. But the difference of GSH-Px activity between simple corn group and corn adding bean puree groups of Keshan disease area was not obvious(P>0.05). Myocardial damage incidence of the three groups was 3/9,1/9,2/7. Difference among three groups did not have statistical significance(χ2=1.33, P> 0.05). Conclusions Only corn from Keshan disease area may induce myocardial damage pathology change. Adding bean puree into corn does not increase damage.

Shenfu Qiangjing decoction improves non-inflammatory and non-liquefied semen in kidney-yang deficiency men / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the clinical efficacy of Shenfu Qiangjing Decoction (SQD) in the treatment of non-inflammatory and non-liquefied semen in infertile males with kidney-yang deficiency.</p><p><b>METHODS</b>Sixty cases of male infertility caused by non-inflammatory and non-liquefied semen with kidney-yang deficiency were equally and randomly divided into an SQD and a control group, the former given oral SQD and the latter vitamin C tablets plus intramuscular chymotrypsin. Both groups were observed for sperm viability, sperm motility, serum testosterone, seminal plasma PSA and improvement of kidney-yang deficiency symptoms before and after the medication. The therapeutic effects were evaluated according to the semen liquefaction within 60 min.</p><p><b>RESULTS</b>Statistically significant differences were observed in the improvement of kidney-yang deficiency symptoms after the medication between the SQD and control groups (P < 0.01, P < 0.05) , and in sperm viability and motility of the SQD group before and after the treatment (P < 0.01) as well as between the two groups after the medication (P < 0.05). The levels of serum T and seminal plasma PSA also showed significant differences before and after the treatment in the SQD group (P < 0.01) and between the two groups after the medication (P < 0.05). The rate of total effectiveness was 93.3% in the SQD and 76.7% in the control group (P < 0.05).</p><p><b>CONCLUSION</b>SQD can shorten the semen liquefaction time in patients with non-inflammatory and non-liquefied semen and restore semen liquefaction to normal in over 90% of the patients. Meanwhile it can also improve the low testosterone level resulting from various kidney-yang deficiency symptoms.</p>