[Effect of No-tillage on Soil Aggregates in Farmland：A Meta Analysis]

In order to clarify the impact of no-tillage on the quality of farmland soil aggregates in China and promote the adaptive application of no-tillage practices， a Meta-analysis was conducted by collecting data from 116 published studies. The effects of no-tillage on aggregate size distribution， mean weight diameter （MWD）， and aggregate-associated C were studied. The results showed that compared with that under tillage， no-tillage significantly increased the proportion of macroaggregates （10.9%） and MWD （12.8%） and decreased the proportion of clay and silt （-15.5%） but had no significant effect on soil microaggregate and aggregate-associated C. The subgroup and Meta regression analysis showed that no-tillage significantly increased the proportion of macroaggregates in Northwest China （17.6%） and MWD in North China （15.4%）. In upland and clay loam， no-tillage increased MWD by 12.6% and 18.4%， respectively. The effect of no-tillage on increasing the proportion of macroaggregates increased with the soil pH. When straw returned， no-tillage significantly increased the proportion of macroaggregates （9.6%） and MWD （11.6%）， but no significant effect of no-tillage on aggregates was found after straw removal. Regarding test duration， short-term （ < 5 a） no-tillage could significantly increase the proportion of macroaggregates， whereas long-term （ > 10 a） no-tillage could improve the MWD. In different soil layers， no-tillage could only significantly improve the aggregate size distribution and MWD in topsoil （0-20 cm） but had no effect in subsoil （ > 20 cm）. In summary， no-tillage could improve aggregate size distribution and stability but had no effect on aggregate-associated C. Production region， soil properties， field management methods， and other factors should be fully considered in production practice to effectively improve the quality of soil aggregates.

[Effect of Biochar on Agricultural Soil Aggregates and Organic Carbon: A Meta-analysis]

As a soil amendment, biochar has been widely used to ameliorate agricultural soil. To ensure the effect of biochar on the carbon sequestration of farmlands in China, a Meta-analysis was carried out via collecting published literatures. We quantitatively analyzed the response of biochar application to soil aggregates, aggregate carbon, and soil organic carbon to different experimental conditions. The results showed that the application of biochar significantly increased the proportion of soil macroaggregates(10.8%) and MWD(13.3%) but had no significant effect on soil microaggregates and silty-clay compared with those in the non-biochar-added treatment. Moreover, biochar addition significantly increased soil organic carbon content(56.9%), with the largest increased area in North China(39.4%), and enhanced intra-aggregate carbon contents of each particle size. Biochar could significantly increase soil organic carbon content under different experimental designs. Compared with that under non-fertilization, biochar combined with fertilization could also significantly improve soil structure and soil fertility. We also found that more than two years of biochar application significantly increased the proportion of macroaggregates(15.7%), MWD(21.2%), macroaggregate carbon(31.7%), and soil organic carbon(40.0%). Meanwhile, biochar produced from crop straw had better soil improvement effects than that of wood and sawdust. Biochar applied in high-nitrogen soil was more beneficial to improve soil stability. Thus, we concluded that biochar could meliorate soil structure and promote the accumulation of soil organic carbon, which was of importance for the fertility maintenance and improvement of the farmland.

[Structure and Function of Soil Fungal Community in Rotation Fallow Farmland in Alluvial Plain of Lower Yellow River]

This study was conducted to clarify the structure and function of the fungal community and the microecology change characteristics of farmland soil fertility response to different fallow rotation patterns. It aimed to provide a reference for promoting farmland ecological restoration and farmland quality improvement in the alluvial plain of the lower Yellow River. Farmland soil subject to a long-term rotation fallow experiment since 2018 was studied using Illumina MiSeq high-throughput sequencing technology, and the 'FUNGuild' fungal function prediction tool was used to analyze differences in soil fungal community structure and function under the following four rotation fallow regimes: long fallow (LF), winter wheat and summer fallow (WF), winter fallow and summer maize (FM), and annual rotation of winter wheat and summer maize (WM). The results showed that LF (fallow lasting two years) increased the richness and diversity of fungal communities in the topsoil (0-20 cm layer), whereas WF increased the richness and diversity of fungi in the deep soil (20-40 cm layer) after winter wheat harvest. A total of 2262 OTU were obtained from all soil samples, which were divided into 14 phyla, 34 classes, 75 orders, 169 families, 309 genera, and 523 species. OTU shared by the two soil layers included 420 types (0-20 cm layer) and 253 types (20-40 cm layer), respectively. The fungal community structure of the four rotation fallow soils was similar at the phylum level, mainly including Ascomycota, Basidiomycota, and Mortierellomycota. The total abundances of the three dominant bacteria were 91.69%-96.91% (0-20 cm layer) and 91.67%-94.86% (20-40 cm layer), respectively. Principal component analysis showed that the first principal component (PC1) and the second principal component (PC2) could explain the difference in community structure by 45.56% (0-20 cm layer) and 46.20% (20-40 cm layer). Additionally, the LDA results of LEfSe (threshold was 4.0) showed that there were 64 fungal evolutionary branches in LF, FM, WF, and WM with statistically significant differences (P<0.05). According to RDA analysis, total organic carbon (TOC), total phosphorus (TP), available nitrogen (AN), and soil water content (SWC) were the main environmental factors that significantly affected fungal community in the 0-40 cm soil layer (P<0.05). The functional prediction with FUNGuild showed that the main nutrient types among different treatments in different soil layers were saprotrophic, saprotrophic-symbiotrophic, pathotrophic-saprotrophic-symbiotrophic, and pathotrophic. In LF, the nutrient type of topsoil was mainly pathotrophic-saprotrophic-symbiotrophic, whereas in deep soil, the relative abundance of pathotrophic fungi was the highest. Additionally, in the treatments with planted wheat or corn (FM, WF, and WM), saprotrophic was the main type in both soil layers. Therefore, different fallow patterns were linked to variation in the structure, diversity, and nutrient types of soil fungal communities. Based on these results, seasonal fallow practices could regulate the farmland soil micro-ecological environment of intensive planting and promote the health and harmony of farmland soil ecosystems.

[Characteristics of Bacterial Community Structure in Fluvo-aquic Soil Under Different Rotation Fallow]

The aim of this study was to provide a reference for promoting ecological restoration of farmland and the green development of agriculture in the alluvial plain of the lower Yellow River by determining the effects of different rotation fallow patterns on the bacterial community of the fluvo-aquic soil. Farmland soil subject to a long-term rotation fallow experiment since 2018 was studied using Illumina MiSeq high-throughput sequencing technology, and the 'Tax4Fun' bacterial function prediction tool was used to analyze differences in soil bacterial community structure and function under the following four rotation fallow regimes:long fallow(LF), winter wheat and summer fallow(WF), winter fallow and summer maize(FM), and annual rotation of winter wheat and summer maize(WM). The environmental factors affecting changes in the soil bacterial community structure and function were also analyzed. In total, 44 phyla, 146 classes, 338 orders, 530 families, 965 genera, and 2073 species of bacteria were detected in the soil samples from the different rotation fallow regimes, and the dominant bacterial groups were Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexi in 0-20 cm and 20-40 cm soil layers. However, the relative abundances of the dominant bacteria groups were varied between the rotation fallow regimes. In the 0-20 cm layer of the seasonal fallow soils(WF and FM), bacteria were more abundant and community diversity was higher than that of the WM and LF soils. In 20-40 cm soil layer, the WF soil was more abundant in bacterial and the community was more diverse. Based on the prediction function of the 'Tax4Fun' tool, six primary metabolic pathways, 40 secondary metabolic pathways(18 types with relative abundance greater than 1%), and 264 tertiary metabolic pathways were identified in the soil bacteria of the different rotation fallow regimes. Seasonal fallow(WF and FM) was found to increase the relative abundance of beneficial bacterial metabolic pathways involved in metabolism, environmental information processing, and genetic information processing. According to RDA analysis, the soil bacterial community in the 0-20 cm soil layer was significantly affected by soil moisture, total phosphorus, available phosphorus, available potassium, pH, and C/N ratio(P<0.05), and the soil bacterial community in 20-40 cm soil layer was significantly affected by soil total phosphorus and available phosphorus(P<0.05). Therefore, different fallow patterns were linked to variation in the structure, diversity, and metabolic functions of soil bacterial communities. Based on these results, seasonal fallow practices could promote the health and stability of farmland soil ecosystems.

CXCL-10/CXCR3 in macrophages regulates tissue repair by controlling the expression of Arg1, VEGFa and TNFα

Macrophages have been reported to participate in inflammation, tissue homeostasis and tissue repair. The detailed mechanism of macrophage-mediated tissue repair is not clear. CXCL-10, secreted by monocytes, endothelial cells and fibroblasts, mediates immune response and angiogenesis by binding to CXCR3. In this study, the expression of CXCL-10 and CXCR3 in porcine lung injury induced by porcine reproductive and respiratory syndrome virus (PRRSV) infection was firstly examined. The results showed that the expression of both CXCL-10 and CXCR3 increased in the infected pig lungs. In addition, the increased expression of CXCL-10 and CXCR3 in macrophage treated by poly (I:C) was also observed, suggesting the autocrine system existed in macrophages. Furthermore, CXCL-10 treatment induced upregulation of Arg1 and VEGFa, and downregulation of TNFα in macrophage, and CXCR3 antagonist AMG487 treatment presented the contrary effects on the expression of Arg1, VEGFa, and TNFα. CXCL- 10-stimulated effects were dependent on PI3K/Akt signaling pathway. Wound-healing assay showed that CXCL-10 treatment macrophage conditioned medium promoted the healing process of endothelial cells. Our results suggested that CXCL-10/CXCR3 in macrophage may mediate tissue repair by regulating the macrophage expression of Arg1, VEGFa and TNFα. Modulation of CXCL-10/CXCR3 axis in macrophage may be a potential therapeutic strategy for tissue injury and repair.

Solexa sequencing of microRNAs on chromium metabolism in broiler chicks

AIM

The aim of this study was to determine the effect of chromium picolinate (CrPic) on the differential expression of the known microRNAs (miRNAs) in broiler skeletal muscle.

METHODS AND RESULTS

A total of 288 1-day-old male Arbor Acres broilers were randomly assigned to one of four dietary treatments supplemented with 0, 0.4, 2.0, or 10.0 mg·kg(-1) CrPic, respectively. Dietary CrPic supplementation at 10.0 mg·kg(-1) increased the average daily feed intake in broilers (p < 0.05). On day 42, the serum total protein level was highest in animals treated with 2.0 mg·kg(-1) (p < 0.05) and 10.0 mg·kg(-1) CrPic (p < 0.05). Dietary supplementation with 10.0 mg·kg(-1) CrPic decreased the levels of serum glucose (p < 0.05) on day 42 and of serum triglyceride (p < 0.05) on days 21 and 42. To further identify miRNAs from broiler skeletal muscles, we sequenced two small RNA libraries using the Solexa sequencing approach, and 57 miRNAs were found to be significantly differentially expressed (p < 0.05). Among them, 6 upregulated and 2 downregulated miRNAs were validated by real-time qPCR (p < 0.05).

CONCLUSIONS

The results of the present study provide a valuable clue regarding the role of miRNA target genes in the mechanism of the dietary CrPic effect on protein synthesis in skeletal muscles of broilers.

Distribution of sorbed phenanthrene and pyrene in different humic fractions of soils and importance of humin

Contributions of fulvic-humic acids (FA/HA) and humin (HM) to sorption of phenanthrene (PHE) and pyrene (PYR) in a soil were differentiated using a humic separation procedure after multi-concentration sorption experiments. It was found that the amount of solutes in FA/HA did not change significantly after 48 h, while that in HM increased continuously and slowly up to the end of the experimental period (720 h), indicating that HM was the main region for slow sorption. Based on the fitting results using Freundlich equation, it was found that nonlinearity of both solutes was greater in HM than in FA/HA, consistent with the sorption characteristics of individually extracted HA and HM in a separate experiment. The observed nonlinearity of the solute distribution was confirmed by using three other soil samples with organic carbon contents ranging from 0.7 to 7.9%. Distribution dynamics of PHE and PYR among various fractions were also discussed.

Electrochemical studies of the effect of lanthanide ions on the activity of glutamate dehydrogenase

Using the electrochemical method based on the "diffusion" layer concept of the convective system, the effect of lanthanide ions La3+ and Eu3+ on the activity of glutamate dehydrogenase (GLDH) has been determined. In suitable concentrations, the lanthanide ions La3+ and Eu3+ can activate the GLDH in the reductive amination of alpha-Ketoglutarate (alpha-KG). The activation mechanism would be that the lanthanide ions could interrupt the binding of NAD+ to GLDH by combining preferentially to NAD+. This mechanism was proposed by the voltammetric studies.

Electrochemical study of the effect of ADP and AMP on the kinetics of glutamate dehydrogenase

A chronoamperometric method based on the 'diffusion' layer concept of the convective system was used to assay the glutamate dehydrogenase (GLDH) activity. Once the reaction was initiated by adding the enzyme GLDH into a well-stirred nicotinamide adenine dinucleotide (NADH, coenzyme) solution, the steady-state oxidation limiting current of NADH would decrease linearly in a short time. The major advantage of this method is that it directly indicates the continuous in-situ change of the coenzyme concentration, thus, the real initial reaction rate of enzyme-catalyzed reaction, V0, can be determined. Using this method, the effect of adenosine-5'-monophosphate (AMP) and adenosine-5'-diphosphate (ADP) on the GLDH activity has been monitored. The results showed that ADP and AMP could increase the activity of GLDH. This activation mechanism was proposed by the voltammetric study.

Surgical resection for recurrent hepatocellular carcinoma: prognosis and analysis of risk factors

BACKGROUND

Hepatocellular carcinoma (HCC) is common in Asian countries, and tumor recurrence is the most common cause of treatment failure after curative resection. Repeated hepatectomy is performed only for selected patients because most patients with HCC also have liver cirrhosis and poor liver function reserve. The purposes of this study were to clarify the outcome of the patients after second hepatectomy for recurrent HCC and to evaluate the prognostic factors after second hepatectomy.

METHODS

We used retrospective cohort study to examine the disease-free survival, cumulative survival, and possible prognostic factors for recurrence and death in 59 patients who underwent surgical resection for recurrent HCC at the National Taiwan University Hospital from August 1986 to December 1993. Another 64 patients with unresectable recurrent HCC were used as a historical control group. The survival curves between those patients with resectable HCC and those with unresectable HCC were compared.

RESULTS

After resection for recurrent HCC, gender and multiplicity (n > 3) of tumor affect recurrence rate (p = 0.046 and 0.021, respectively), whereas gender, age, and tumor invasiveness affect survival rate significantly (p = 0.024, 0.021, and 0.046, respectively). The survival rate of patients with resectable HCC was significantly better than that of those with unresectable HCC.

CONCLUSIONS

For recurrent HCC surgical resection is an effective mode of treatment in selected patients. Whether surgery is better than other modes of treatment in the treatment of resectable recurrent HCC demands further investigation.

A high sensitivity LiF thermoluminescent dosimeter--LiF(Mg, Cu, P)

This paper describes the dosimetric properties of a new, high-sensitivity thermoluminescence dosimeter material prepared in our laboratory. The sensitivity of the LiF(Mg, Cu, P) phosphor is about 23 times higher than that of LiF (TLD-100). Its TL response is linear from 0.3 mR to 1000 R. Its energy dependence is similar to that of LiF (TLD-100). It is stable and reusable without significant loss of sensitivity. Its application to environmental radiation monitoring is described.