[Randomized controlled study on the application effect of a new type of intravenous radiofrequency closed therapy system made in China and an imported system]

Objective: To compare the application effect of domestic and imported intravenous radiofrequency closure system in the treatment of primary varicose veins of lower extremities. Methods: This single-center prospective, non-inferiority randomized controlled trial was performed in the Department of Vascular Surgery, the Fourth Affiliated Hospital, Zhejiang University School of Medicine from January 2021 to January 2022. Patients with primary varicose veins of lower extremities who met the ataxation criteria were randomly assigned to the experimental group(domestic novel venous radiofrequency closure system) or the control group(imported venous radiofrequency closure system) in a ratio of 1∶1. The two groups of subjects were compared in terms of target vein closure rate, technical success rate, system operation performance, incidence of adverse events and incidence of serious adverse events(SAE) within 6 months after surgery. Quantitative data were compared by Mann-Whitney U test, and categorical data were compared by χ2 test and non-inferiority test. Results: A total of 80 subjects were included in the trial (41 in the experimental group and 39 in the control group), including 27 males and 53 females, aged (M(IQR)) 55(23) years (range:40 to 78 years). There were 48 cases of left lower limb and 32 cases of right lower limb. The technical success rate and system control performance between the groups were 100%.The incidence of adverse events (58.5% (24/41) vs. 61.5% (24/39), χ2=0.075, P=0.784), and the incidence of SAE (7.3% (3/41) vs. 5.1% (2/39), χ2=0.163, P=0.686) within 6 months after surgery in experimental group and control group had no statistical significance. There was one device-related adverse event in each of the two groups. In the experimental group, one patient developed endovenous heat-induced thrombosis after surgery and recovered after taking rivaroxaban tablets. One patient in the control group had pain in the upper right thigh for more than 1 day after operation, which was cured after using analgesic cream. No device-related SAE occurred. The venous closure rate of the experimental group was 100% (38/38) at 6 months after surgery, and that of the control group was 97.4% (37/38). The difference between the two groups was 2.63% (95%CI:-3.19 to 8.45, Z=4.865, P<0.01), and the 95%CI lower limit of the difference in target venous closure rate between two groups was greater than the non-inferiority threshold of -10.00%. Conclusion: The early application effect of the new domestic intravenous radiofrequency closure system in patients with primary varicose veins of lower extremities is in line with expectations, it is not inferior to the imported system.

[Interpretation of Chinese expert consensus on the surgical treatment for adenocarcinoma of esophagogastric junction(2024 edition)]

Due to the unique nature of its anatomical location, the adenocarcinoma of esophagogastric junction (AEG) has been a subject of controversy and disagreement including its definition, staging, and treatment strategies. Chinse expert Consensus on Surgical Treatment of Adenocarcinoma of Esophagogastric Junction in China (2018 Edition) had been released in September 2018 and had played a pioneering role in unifying thoracic and general surgeons in China on surgical treatment strategies for AEG. Over the past five years, the emergence of several clinical research results on AEG has provided new clinical evidence for the selection of key surgical treatment strategies. Therefore, to further standardize the surgical treatment of AEG in China, Chinese Expert Consensus on Surgical Treatment of Adenocarcinoma of Esophagogastric Junction in China (2024 Edition) was released in 2024 by Chinese expert panel including 25 gastrointestinal surgeons and 24 thoracic surgeons. Based on the highest-level clinical research evidence in recent 5 years, this consensus ultimately formulates 29 recommendations on hotspots and key points on surgical treatment of AEG and summary 5 issues that are still awaiting further exploration. This review will provide a summary and detailed interpretation of the recommendations outlined in this consensus.

[Updates of colonoscopy surveillance guidelines after screening and polypectomy, and related research progress]

With the widespread application of colorectal cancer screening, the surveillance and management of the increasing number of screened population has become a pivotal aspect in preventing and controlling colorectal cancer. In recent years, researches have been conducted on the risk of colorectal cancer incidence and mortality in the population after screening. At the same time, various organizations in Europe and the United States have continuously updated colonoscopy surveillance after screening and polypectomy based on the latest research evidence. In this review, we summarized the current progress of studies on colorectal cancer risk in post-screening colorectal cancer populations and the key points of relevant guideline updates, in order to provide a reference for conducting relevant studies and formulating surveillance guidelines or consensus in China.

The marriage of immunomodulatory, angiogenic, and osteogenic capabilities in a piezoelectric hydrogel tissue engineering scaffold for military medicine

BACKGROUND

Most bone-related injuries to grassroots troops are caused by training or accidental injuries. To establish preventive measures to reduce all kinds of trauma and improve the combat effectiveness of grassroots troops, it is imperative to develop new strategies and scaffolds to promote bone regeneration.

METHODS

In this study, a porous piezoelectric hydrogel bone scaffold was fabricated by incorporating polydopamine (PDA)-modified ceramic hydroxyapatite (PDA-hydroxyapatite, PHA) and PDA-modified barium titanate (PDA-BaTiO₃, PBT) nanoparticles into a chitosan/gelatin (Cs/Gel) matrix. The physical and chemical properties of the Cs/Gel/PHA scaffold with 0-10 wt% PBT were analyzed. Cell and animal experiments were performed to characterize the immunomodulatory, angiogenic, and osteogenic capabilities of the piezoelectric hydrogel scaffold in vitro and in vivo.

RESULTS

The incorporation of BaTiO₃ into the scaffold improved its mechanical properties and increased self-generated electricity. Due to their endogenous piezoelectric stimulation and bioactive constituents, the as-prepared Cs/Gel/PHA/PBT hydrogels exhibited cytocompatibility as well as immunomodulatory, angiogenic, and osteogenic capabilities; they not only effectively induced macrophage polarization to M2 phenotype but also promoted the migration, tube formation, and angiogenic differentiation of human umbilical vein endothelial cells (HUVECs) and facilitated the migration, osteo-differentiation, and extracellular matrix (ECM) mineralization of MC3T3-E1 cells. The in vivo evaluations showed that these piezoelectric hydrogels with versatile capabilities significantly facilitated new bone formation in a rat large-sized cranial injury model. The underlying molecular mechanism can be partly attributed to the immunomodulation of the Cs/Gel/PHA/PBT hydrogels as shown via transcriptome sequencing analysis, and the PI3K/Akt signaling axis plays an important role in regulating macrophage M2 polarization.

CONCLUSION

The piezoelectric Cs/Gel/PHA/PBT hydrogels developed here with favorable immunomodulation, angiogenesis, and osteogenesis functions may be used as a substitute in periosteum injuries, thereby offering the novel strategy of applying piezoelectric stimulation in bone tissue engineering for the enhancement of combat effectiveness in grassroots troops.

[Clinicopathological characteristics and prognosis of patients with small bowel tumors: A single center analysis of 220 cases]

Objective: To analyze the clinicopathological characteristics and prognosis of patients with small bowel tumors. Methods: This was a retrospective, observational study. We collected clinicopathological data of patients with primary jejunal or ileal tumors who had undergone small bowel resection in the Department of Gastrointestinal Surgery, West China Hospital, Sichuan University between January 2012 and September 2017. The inclusion criteria included: (1) older than 18 years; (2) had undergone small bowel resection; (3) primary location at jejunum or ileum; (4) postoperative pathological examination confirmed malignancy or malignant potential; and (5) complete clinicopathological and follow-up data. Patients with a history of previous or other concomitant malignancies and those who had undergone exploratory laparotomy with biopsy but no resection were excluded. The clinicopathological characteristics and prognoses of included patients were analyzed. Results: The study cohort comprised 220 patients with small bowel tumors, 136 of which were classified as gastrointestinal stromal tumors (GISTs), 47 as adenocarcinomas, and 35 as lymphomas. The median follow-up for all patient was 81.0 months (75.9-86.1). GISTs frequently manifested as gastrointestinal bleeding (61.0%, 83/136) and abdominal pain (38.2%, 52/136). In the patients with GISTs, the rates of lymph node and distant metastasis were 0.7% (1/136) and 11.8% (16/136), respectively. The median follow-up time was 81.0 (75.9-86.1) months. The 3-year overall survival (OS) rate was 96.3%. Multivariate Cox regression-analysis results showed that distant metastasis was the only factor associated with OS of patients with GISTs (HR=23.639, 95% CI: 4.564-122.430, P<0.001). The main clinical manifestations of small bowel adenocarcinoma were abdominal pain (85.1%, 40/47), constipation/diarrhea (61.7%, 29/47), and weight loss (61.7%, 29/47). Rates of lymph node and distant metastasis in patients with small bowel adenocarcinoma were 53.2% (25/47) and 23.4% (11/47), respectively. The 3-year OS rate of patients with small bowel adenocarcinoma was 44.7%. Multivariate Cox regression-analysis results showed that distant metastasis (HR=4.018, 95%CI: 2.108-10.331, P<0.001) and adjuvant chemotherapy (HR=0.291, 95% CI: 0.140-0.609, P=0.001) were independently associated with OS of patients with small bowel adenocarcinoma. Small bowel lymphoma frequently manifested as abdominal pain (68.6%, 24/35) and constipation/diarrhea (31.4%, 11/35); 77.1% (27/35) of small bowel lymphomas were of B-cell origin. The 3-year OS rate of patients with small bowel lymphomas was 60.0%. T/NK cell lymphomas (HR= 6.598, 95% CI: 2.172-20.041, P<0.001) and adjuvant chemotherapy (HR=0.119, 95% CI: 0.015-0.925, P=0.042) were independently associated with OS of patients with small bowel lymphoma. Small bowel GISTs have a better prognosis than small intestinal adenocarcinomas (P<0.001) or lymphomas (P<0.001), and small bowel lymphomas have a better prognosis than small bowel adenocarcinomas (P=0.035). Conclusions: The clinical manifestations of small intestinal tumor are non-specific. Small bowel GISTs are relatively indolent and have a good prognosis, whereas adenocarcinomas and lymphomas (especially T/NK-cell lymphomas) are highly malignant and have a poor prognosis. Adjuvant chemotherapy would likely improve the prognosis of patients with small bowel adenocarcinomas or lymphomas.

[Network meta-analysis comparing the clinical outcomes and safety of robotic, laparoscopic, and transanal total rectal mesenteric resection for rectal cancer]

Objective: To methodically assess the clinical effectiveness and safety of robot-assisted total rectal mesenteric resection (RTME), laparoscopic-assisted total rectal mesenteric resection (laTME), and transanal total rectal mesenteric resection (taTME). Methods: A computer search was conducted on PubMed, Embase, Cochrane Library, and Ovid databases to identify English-language reports published between January 2017 and January 2022 that compared the clinical efficacy of the three surgical procedures of RTME, laTME, and taTME. The quality of the studies was evaluated using the NOS and JADAD scales for retrospective cohort studies and randomized controlled trials, respectively. Direct meta-analysis and reticulated meta-analysis were performed using Review Manager software and R software, respectively. Results: Twenty-nine publications comprising 8,339 patients with rectal cancer were ultimately included. The direct meta-analysis indicated that the length of hospital stay was longer after RTME than after taTME, whereas according to the reticulated meta-analysis the length of hospital stay was shorter after taTME than after laTME (MD=-0.86, 95%CI: -1.70 to -0.096, P=0.036). Moreover, the incidence of anastomotic leak was lower after taTME than after RTME (OR=0.60, 95%CI: 0.39 to 0.91, P=0.018). The incidence of intestinal obstruction was also lower after taTME than after RTME (OR=0.55, 95%CI: 0.31 to 0.94, P=0.037). All of these differences were statistically significant (all P<0.05). There were no statistically significant differences between the three surgical procedures regarding the number of lymph nodes cleared, length of the inferior rectal margin, or rate of positive circumferential margins (all P>0.05). An inconsistency test using nodal analysis revealed no statistically significant differences between the results of direct and indirect comparisons of the six outcome indicators (all P>0.05). Furthermore, we detected no significant overall inconsistency between direct and indirect evidence. Conclusion: taTME has advantages over RTME and laTME, in terms of radical and surgical short-term outcomes in patients with rectal cancer.

[Effects of Short-term Nitrogen Addition on Soil Organic Carbon Components in Robinia pseudoacacia L. Plantation]

Nitrogen (N) deposition in the context of human activities continuously affects the carbon cycle of ecosystems. The effect of N deposition on soil organic carbon is related to the differential responses of different carbon fractions. To investigate the changes in soil organic carbon fraction and its influencing factors in the context of short-term N deposition, four N addition gradients:0 (CK), 1.5 (N1), 3 (N2), and 6 (N3) g·(m²·a)^-1 were set up in acacia plantations based on field N addition experiments, and the soil physicochemical properties, microbial biomass, and enzyme activities were measured in June and September. The results showed that:① exogenous N input reduced soil pH, promoted the increase in soluble organic carbon content, and increased soil nitrogen effectiveness. ② Short-term N addition significantly reduced soil organic carbon content, and the response of each component of organic carbon to N addition was different. Among them, the content of easily oxidized organic carbon was significantly reduced and reached the lowest value under the N2 treatment, with 54.4% and 48.2% reduction compared with that of the control, respectively, and the content of inert organic carbon increased, although the increase was not significant. Nitrogen addition reduced the soil carbon pool activity and improved the stability of the soil carbon pool. Soil carbon pool activity reached its lowest under the N3 and N2 treatments, with a decrease of 53.3% and 52.80%, respectively, compared to that of the control. ③Random forest modeling indicated that the soil microbial biomass stoichiometry ratio, microbial biomass carbon, and AP were the key factors driving the changes in soil organic carbon activity under short-term N addition, explaining 65.96% and 66.68% of the changes in oxidizable organic carbon and inert organic carbon, respectively. Structural equation modeling validated the results of the random forest modeling, and soil microbial biomass stoichiometric ratios significantly influenced carbon pool activity. Short-term nitrogen addition changed soil microbial biomass and its stoichiometric ratio in the acacia plantation forest mainly through two pathways, i.e., increasing soil nitrogen effectiveness and promoting soil acidification and inhibiting extracellular carbon hydrolase activity, thus changing the soil carbon fraction ratio and participating in the soil organic carbon cycling process.

[Mineralization Characteristics of Soil Organic Carbon and Its Relationship with Organic Carbon Components in Artificial Robinia pseudoacacia Forest in Loess Hilly Region]

In order to explore the characteristics of organic carbon mineralization and the variation law of organic carbon components of an artificial forest in a loess hilly area, an artificial Robinia pseudoacacia forest restored for 13 years and the adjacent slope farmland were selected as the research objects, and indoor culture experiments under three different temperature treatments (15, 25, and 35℃) were carried out. The results indicated that the mineralization rate of soil organic carbon decreased sharply at first and then stabilized. The cumulative release of organic carbon increased rapidly in the initial stage of culture and gradually slowed in the later stage. Soil organic carbon mineralization in sloping farmland was more sensitive to temperature change, and its temperature sensitivity coefficient Q₁₀ was 1.52, whereas that in R. pseudoacacia forest land was only 1.38. According to the fitting of the single reservoir first-order dynamic equation, the soil mineralization potential C_p of R. pseudoacacia forest land and slope farmland was between 2.02-4.32 g·kg^-1 and 1.25-3.17 g·kg^-1, respectively, that is, the mineralization potential of the R. pseudoacacia forest was higher. During the cultivation period, the content of various active organic carbon components decreased with time, and that in the R. pseudoacacia forest land was greater than that in the slope land. The cumulative carbon release of soil was significantly positively correlated with the contents of MBC and DOC (P<0.05), and Q₁₀ (15-25℃) was negatively correlated with the contents of SOC, EOC, and SWC (P<0.05). These results could provide some reference for the study of soil carbon sequestration in loess hilly regions under climate change.

[Establishment of High-Resolution Emissions Inventory in Wuhai and Its Application in Exploring the Causes of Ozone Pollution]

Wuhai is a typical coking industrial base including three industrial parks within its jurisdiction. The emission amount of air pollutants is considerable here, and O₃ pollution has become serious in recent years. Clarifying the air pollutant emission characteristics and exploring the formation mechanism of O₃ are the basis for objectively understanding the O₃ pollution and formulating scientific prevention and control measures. This study established the high-resolution emission inventory of Wuhai in 2018 (HEI-WH18) based on the "coefficient method," evaluated the applicability and accuracy of HEI-WH18 using the WRF-Chem model, and explored the causes of O₃ pollution in summer using WRF-Chem diagnosis module output. The HEI-WH18 showed that the total emissions amount of SO₂, NO_x, CO, PM₁₀, PM_2.5, VOCs, NH₃, BC, and OC were 65943, 40934, 172867, 159771, 47469, 69191, 1407, 1491, and 1648 t·a^-1, respectively. HEI-WH18 could capture the variation and magnitude of O₃ and its precursors better than the MEIC, which was suitable for the O₃ simulation and source analysis in summer. From the perspective of spatial distribution, Haibowan was a high-value area of O₃ during the daytime, and the three industrial parks were low-value areas of O₃ and high-value areas of NO₂ during the daytime and nighttime. The spatial distribution characteristics of CO were consistent with the spontaneous combustion of coal and coal gangue sources. According to the diagnostic analysis of two O₃ pollution processes, the O₃ increase in the upper boundary layer was mainly related to the advection transport and chemical process, and it was caused by vertical mixing and the advection transport process in the lower boundary layer. The contribution of the chemical process in the lower boundary layer was complicated, and its positive contribution played a role in maintaining a high O₃ concentration, whereas its negative contribution combined with advection transport resulted in the final dissipation of O₃ pollution.

[Expression of PD-L1 and tumor infiltrating lymphocyte markers in uterine cervical carcinoma]

Objective: To investigate the expression of PD-L1, CD4, CD8 and CXCL-13 in cervical carcinoma, and their clinicopathological significance was analyzed. Methods: A total of 77 patients with cervical carcinoma in the Seventh Medical Center, PLA General Hospital from January 2019 to December 2021 were included. All patients received radical surgical resection in the Seventh Medical Center of Chinese PLA General Hospital. The expression of PD-L1, CD4, CD8 and CXCL-13 was detected by immunohistochemical (IHC) method. The correlation between IHC markers and patients' clinicopathological parameters was analyzed. Results: There were 59 cases of squamous cell carcinoma and 18 cases of adenocarcinoma (ranging from 29 to 69 years) with an average of (49.4±9.8) years. PD-L1 was expressed in different degrees in cervical squamous cell carcinoma and adenocarcinoma (χ²=4.975, P=0.026); CD4⁺, CD8⁺and CXCL-13⁺tumor infiltrating lymphocytes (TIL) were observed in the carcinoma cell nests and peritumoral stroma. PD-L1 expression in cervical carcinoma was moderately correlated with the number of CD4⁺TIL in the carcinoma nests, and the number of CD8⁺, CXCL-13⁺TIL infiltration in the carcinoma nests and stroma, but not to the patient's age, histologic differentiation, presence or absence of vascular invasion, presence or absence of lymph node metastasis and FIGO stage (P>0.05). Conclusions: The high expression of PD-L1 in cervical carcinoma tissues is closely related to the number of TIL in the carcinoma nests and peritumor stroma, suggesting that they may have important reference value for predicting the response to immunotherapy in patients with cervical carcinoma.

[Characteristics of SARS-CoV-2 Omicron infection in children imported from Hong Kong]

Objective: To understand the clinical characteristics of children with SARS-CoV-2 Omicron infection imported from Hong Kong Special Administrative Region. Methods: This retrospective study was conducted to collect the data including clinical manifestations, outcomes and vaccination of 107 children with SARS-CoV-2 Omicron infection imported from Hong Kong Special Administrative Region to be admitted to the designated referral hospital in Shanghai from February to March 2022. According to the occurrence of clinical symptoms, the cases were divided into asymptomatic group and symptomatic group. According to the age of diagnosis, the cases were divided into <3 years group, 3-<6 years group and 6-<18 years group, and the clinical manifestations in different age group were analyzed with t-test and Mann-Whitney rank-sum test. Besides, to analyze the effectiveness of vaccination against SARS-CoV-2 Omicron infection in different age group, the cases aged 3-<18 years were also subdivided into unvaccinated group, 1-dose group and 2-dose group, and the relative risk (RR) was used to demonstrate the effectiveness. Results: Among the 107 cases, 66 were male and 41 were female, with infection age of 10 (5, 14) years. There were 29 cases in the asymptomatic group, and 78 cases in the symptomatic group, and no significant difference in the age of infection was observed between the 2 groups (11 (6, 14) vs. 10 (5, 14) years, Z=0.49, P>0.05). And there were no severe cases in symptomatic group. The length of hospitalization was (18±6) days, and was longer in symptomatic group than that in asymptomatic group ((19±6) vs. (16±7) d, t=0.17, P=0.030). Eight-two cases (76.6%) had a history of epidemiological exposure and, among whom, 81 cases (75.7%) were associated with household transmission. Among symptomatic group, 57 cases (73.1%) had fever and 20 cases (25.6%) had cough. Of the 74 cases undergoing chest CT examination, 17 cases (23.0%) showed mild abnormalities. Of the 83 cases who received the lab tests, 23 cases (27.7%) had white blood cell counts<4×10⁹/L, 3 cases (3.6%) had C-reaction protein >8.0 mg/L, and 6 cases (7.2%) had slightly elevated aspartate transaminase and alanine aminotransferase. Among the 92 children aged 3-<18 years, 31 cases were unvaccinated, 34 cases received 1 dose, and 27 cases received 2 doses. The interval between the last vaccination and infection was 2.2 (0.6, 6.0) months; the interval between the last vaccination and infection in the 2-dose group was longer than that in 1-dose group (6.0 (4.5, 7.3) vs. 0.7 (0.3,2.0) months, Z=3.59, P<0.001).The risk of symptomatic infection was reduced by 45% (RR=0.55, 95% CI 0.35-0.87) with two-dose vaccination compared to non-vaccination in cases aged 3-<18 years. All these cases recovered completely. Conclusions: Children infected with SARS-CoV-2 Omicron are usually mild or asymptomatic. Household transmission is the main pattern of infection with SARS-CoV-2 Omicron in children. Two-dose SARS-CoV-2 vaccination in children aged 3-<18 years can provide partial protection against disease caused by SARS-CoV-2 Omicron.

[Effects of Warming and Increased Precipitation on Soil Respiration of Abandoned Grassland in the Loess-Hilly Regions]

Clarifying the changing trends and driving factors of soil respiration in fragile habitats under the background of climate change is of great significance for understanding the regional carbon cycle and the conversion of ecosystem carbon source and sink functions. This research focused on grasslands that had been naturally abandoned and restored for 12 years in the loess hilly region of northern Shaanxi, using an open top chamber (OTC) and artificially increased natural rainfall to simulate climate warming and precipitation increase and their interaction. Furthermore, we used a combination of field monitoring and indoor analysis to explore soil water content, temperature, and nutrient characteristics and the response characteristics of soil respiration rate to warming and increased precipitation and further analyzed the key factors driving changes in soil respiration. The results showed that:① warming (W) significantly increased the 5 cm soil temperature, with an average increase of 1.34℃ throughout the sampling year, whereas the increased precipitation (P50%) treatment significantly reduced the 5 cm soil temperature, reducing the average 5 cm soil temperature during the entire sampling year by 0.88℃ and increasing the soil water content (SWC) at the same time. The SWC was 13.12% and 16.45% higher than that in the control (CK), respectively. In addition, compared with that in the CK, the treatment of warming and increased precipitation (WP50%) not only increased soil temperature but also increased SWC; in general, the increase in temperature and precipitation played an antagonistic effect on the influence of soil temperature and humidity. ② P50% significantly increased the content of soil organic carbon, dissolved organic carbon, and labile organic carbon, causing changes in the soil stoichiometric ratio and the distribution characteristics of labile-recalcitrant carbon components, whereas W did not have a significant impact on organic carbon. In addition, soil total nitrogen and phosphorus and available nitrogen and phosphorus nutrients were not significantly different between treatments. ③ P50% significantly increased the R_s rate, and the effect of W on the soil respiration rate mainly depended on the seasonal precipitation and temperature. It was demonstrated that warming in winter and seasons with abundant rainfall had a significant promotion effect on the soil respiration rate. The exponential fitting of soil respiration rate and 5 cm soil temperature found that the soil respiration temperature sensitivity (Q₁₀) was the highest under the precipitation treatment, reaching 1.68, whereas the Q₁₀ was the lowest under the warming treatment (1.50). ④ Linear regression analysis showed that soil organic carbon, dissolved organic carbon, and labile organic carbon were all significantly positively correlated with soil respiration rate. Variation partitioning analysis showed that soil temperature, SWC, and nutrient characteristics explained 64.43% of the variation in soil respiration rate. The soil temperature and SWC were the main controlling factors of the change in soil respiration rate, with an explanation degree of 31.16%. Correlation analysis also showed that there was a significant correlation between SWC, soil temperature and respiration rate, soil organic carbon, dissolved organic carbon, labile organic carbon, C:N, and C:P. In summary, the climate prediction of abandoned grassland tending toward warm temperatures and high humidity in the loess hilly region will significantly affect the regional hydrothermal environment and nutrient characteristics, change the distribution ratio of soil labile and recalcitrant carbon, and promote regional soil carbon emissions. The analysis results showed that the key factor driving the change in soil respiration rate of abandoned grassland in the loess hilly region was soil temperature and SWC characteristics.

[Improved Performance of PMF Source Apportionment for Volatile Organic Compounds Based on Classification of VOCs' Aging Degree in Air Mass]

VOCs are the key precursors of ozone and secondary organic aerosols. The results of source apportionment for VOCs are very important for the coordinated control of ozone and second organic particulate matter. However, VOCs do not fully meet the assumption of the receptor model because the VOCs released from each source are relatively unstable in the transmission process for their reactivity. As a result, we do not accurately obtain the actual source contribution when the receptor model is used for the source apportionment of VOCs. In order to solve the problem that the relative changes in the components caused by VOCs reactivity are not consistent with the PMF model hypothesis, the aging degree of VOCs was introduced to distinguish the state characteristics after their photochemical reactions in the ambient air. According to the ratio of ethylbenzene to m/p-xylene, VOCs monitored at Wuhai were divided into three aging states:high, medium, and low. The results showed that the model parameters, such as regression equation parameters (slope and intercept), standard error, determination coefficient, and pass rate of residual error, were improved obviously compared to the sample set after classification. Because the degree of aging is closely related to the transport time of air mass and the atmospheric oxidation in the atmosphere, it also reflects the different sources of air mass to some extent. In the high-aging VOCs samples, the coking source occupied a high proportion (up to 47.20%). In the low-aging VOCs samples, the combustion source and coking source accounted for a higher proportion, 28.67% and 24.39%, respectively. After the classification according to the aging degree, the results of VOCs source apportionment by PMF are more consistent with the actual contribution of emission sources.

Plant Biomass and Soil Nutrients Mainly Explain the Variation of Soil Microbial Communities During Secondary Succession on the Loess Plateau

Soil microorganisms play an important role in the circulation of materials and nutrients between plants and soil ecosystems, but the drivers of microbial community composition and diversity remain uncertain in different vegetation restoration patterns. We studied soil physicochemical properties (i.e., soil moisture, bulk density, pH, soil nutrients, available nutrients), plant characteristics (i.e., Shannon index [H_Plant] and Richness index [S_Plant], litter biomass [LB], and fine root biomass [FRB]), and microbial variables (biomass, enzyme activity, diversity, and composition of bacterial and fungal communities) in different plant succession patterns (Robinia pseudoacacia [MF], Caragana korshinskii [SF], and grassland [GL]) on the Loess Plateau. The herb communities, soil microbial biomass, and enzyme activities were strongly affected by vegetation restoration, and soil bacterial and fungal communities were significantly different from each other at the sites. Correlation analysis showed that LB and FRB were significantly positively correlated with the Chao index of soil bacteria, soil microbial biomass, enzyme activities, Proteobacteria, Zygomycota, and Cercozoa, while negatively correlated with Actinobacteria and Basidiomycota. In addition, soil water content (SW), pH, and nutrients have important effects on the bacterial and fungal diversities, as well as Acidobacteria, Proteobacteria, Actinobacteria, Nitrospirae, Zygomycota, and microbial biomass. Furthermore, plant characteristics and soil properties modulated the composition and diversity of soil microorganisms, respectively. Overall, the relative contribution of vegetation and soil to the diversity and composition of soil bacterial and fungal communities illustrated that plant characteristics and soil properties may synergistically modulate soil microbial communities, and the composition and diversity of soil bacterial and fungal communities mainly depend on plant biomass and soil nutrients.

[Molluscicidal effect of immersion with 50% wettable powder of niclosamide ethanolamine salt against Oncomelania hupensis on the soil surface and inside the soil layer in winter]

OBJECTIVE

To evaluate the molluscicidal effect of 50% wettable powder of niclosamide ethanolamine salt (WPNES) against Oncomelania hupensis on the soil surface and inside the soil layer by immersion method in winter.

METHODS

O. hupensis snails were placed on the soil surface and 2, 5 cm and 10 cm under the soil layer outdoors in winter, and then immersed in 50% WPNES at concentrations of 1 mg/L and 2 mg/L for 1, 3 d and 7 d, while dechlorinated water served as controls. Snail mortality was observed following immersion with 50% WPNES on the soil surface and inside the soil layer.

RESULTS

Following immersion with 50% WPNES at concentrations of 2 mg/L and 1 mg/L outdoors in winter, the 3-day corrected snail mortality rates were 98.0% and 76.0% on the soil surface, and the 7-day corrected snail mortality rate was both 100.0%. Following immersion with 50% WPNES at concentrations of 2 mg/L and 1 mg/L outdoors in winter, the 7-day corrected snail mortality rates were 95.5% and 85.6% 2 cm below the soil layer, 66.0% and 6.4% 5 cm below the soil layer. However, the 7-day snail mortality rate swere comparable between the 50% WPNES treatment group (at 2 mg/L and 1 mg/L) and controls 10 cm below the soil layer (both P > 0.05).

CONCLUSIONS

Immersion of 50% WPNES at a concentration of 2 mg/L for 7 days presents a high molluscicidal efficacy against O. hupensis on the soil surface and 5 cm within the soil layers in winter.

[Mental health status and its influencing factors of nurses in geriatric department after workplace violence]

Objective: To investigate the mental health status and influencing factors of geriatric nurses after workplace violence. Methods: From February 2019 to January 2020, 102 geriatric nurses who suffered workplace violence in three hospitals in Shaoxing were collected as the observation group and 100 geriatric nurses who did not suffer workplace violence in the same period as the control group. The general data of nurses in the two groups were investigated, the workplace violence was investigated with the hospital workplace violence questionnaire, the mental disorders and mental diseases were investigated with the symptom checklist 90 (SCL-90) , the symptoms of post-traumatic stress disorder were investigated with the symptom checklist of post-traumatic stress disorder (pcl-c) , and the psychological elasticity was investigated with the psychological elasticity scale, Social support was investigated with social support scale (SSRs) . Results: The total average score of symptom checklist 90 (SCL-90) of nurses with workplace violence was (1.49 ± 0.48) . Compared with the control group, the total average score of SCL-90, somatization, obsessive-compulsive symptoms, depression, anxiety and fear factors in the observation group were significantly increased (P<0.05) . The total score of post-traumatic stress disorder symptom list (pcl-c) in the observation group was (34.51±9.87) . Compared with the control group, the total average score of pcl-c, re experience, avoidance and vigilance factors in the observation group were significantly increased (P<0.05) . The total average score of SCL-90 of nurses with workplace violence was positively correlated with psychological elasticity and social support (P<0.05) . Multivariate linear analysis showed that psychological elasticity, tenacity and control, optimism, social support and subjective support were the main factors affecting nurses＇mental health. Conclusion: Geriatric nurses suffering from workplace violence are prone to mental health problems and post-traumatic stress disorder, which should be improved by improving their psychological elasticity and social support.

[Consistency of peripheral whole blood and venous serum procalcitonin in children: a multicenter parallel controlled study]

Objective: To explore the consistency of peripheral whole blood and venous serum procalcitonin (PCT) levels, and the value of peripheral whole blood PCT in evaluating pediatric bacterial infection. Methods: This multicenter cross-sectional parallel control study was conducted in 11 children's hospital. All the 1 898 patients older than 28 days admitted to these hospitals from March 2018 to February 2019 had their peripheral whole blood and venous serum PCT detected simultaneously with unified equipment, reagent and method. According to the venous serum PCT level, the patients were stratified to subgroups. Analysis of variance and chi-square test were used to compare the demographic characteristics among groups. And the correlation between the peripheral blood and venous serum PCT level was investigated by quantitative Pearson correlation analysis.The PCT resultes were also converted into ranked data to further test the consistency between the two sampling methods by Spearman's rank correlation test. Furthermore, the ranked data were converted into binary data to evaluate the consistency and investigate the best cut-off of peripheral blood PCT level in predicting bacterial infection. Results: A total of 1 898 valid samples were included (1 098 males, 800 females),age 27.4(12.2,56.7) months. There was a good correlation between PCT values of peripheral whole blood and venous serum (r=0.97, P<0.01). The linear regression equation was PCT_{venous serum}=0.135+0.929×PCT_{peripheral whole blood}. However, when stratified to 5 levels, PCT results showed diverse and unsatisfied consistency between the two sampling methods (r=0.51-0.92, all P<0.01). But after PCT was converted to ordinal categorical variables, the stratified analysis showed that the coincidence rate of the measured values by the two sampling methods in each boundary area was 84.9%-97.1%. The dichotomous variables also showed a good consistency (coincidence rate 96.8%-99.3%, Youden index 0.82-0.89). According to the severity of disease, the serum PCT value was classified into 4 intervals（<0.5、0.5-<2.0、2.0-<10.0、≥10.0 μg/L）, and the peripheral blood PCT value also showed a good predictive value (AUC value was 0.991 2-0.997 9). The optimal cut points of peripheral whole blood PCT value 0.5、1.0、2.0、10.0 μg/L corresponding to venous serum PCT values were 0.395, 0.595, 1.175 and 3.545 μg/L, respectively. Conclusions: There is a good correlation between peripheral whole blood PCT value and the venous serum PCT value, which means that the peripheral whole blood PCT could facilitate the identification of infection and clinical severity. Besides, the sampling of peripheral whole blood is simple and easy to repeat.

[Establishment of a High-resolution Anthropogenic Emission Inventory and Its Evaluation Using the WRF-Chem Model for Lanzhou]

City-scale high-resolution anthropogenic emission inventories are an important tool for ambient air quality forecasting and early warning, the analysis of underlying causes, and policy making. At present, city-scale anthropogenic emissions inventories for use in air quality models are scarce for West China. By studying the literature on emission inventories, this paper establishes a city-scale anthropogenic emission inventory for Lanzhou (HEI-LZ16) as the basis for an air quality model. The weather research and forecasting with chemistry (WRF-Chem) model was used to evaluate the applicability of the emission inventory at different resolutions in Lanzhou. The results showed that the emission amounts of SO₂, NO_x, CO, NH₃, VOCs, PM₁₀, PM_2.5, BC, and OC in Lanzhou were 25642, 53998, 319003, 10475, 35289, 49250, 19822, 2476, and 1482 t·a^-1 in 2016,respectively. Compared with the simulation scenario of multi-resolution emission inventory for China (MEIC), normalized mean error (NME) of O₃ and PM_2.5 under the HEI-LZ16 scenario decreased by 140.2% and 28.8%, respectively. The HEI-LZ16 inventory is more suitable for application in air pollution research in Lanzhou, which was verified by the WRF-Chem model and the observational data. The spatiotemporal distributions of PM_2.5 and O₃ were also analyzed using the HEI-LZ16 scenario. The ozone concentration of the maximum daily 8-h average (MDA8) in Lanzhou was low in urban areas and high in the suburbs during winter and spring, and high in the west of the urban valley and its downwind areas during summer and autumn. MDA8 in summer and autumn was influenced by easterly winds and photochemical reactions. In winter, ozone concentrations in urban areas are suppressed by NO_x emissions but the concentration decreases. High PM_2.5 concentrations are mainly concentrated within the Yellow River Valley. This study shows that there is a pollutant transmission channel along the western side of the Baiyin-Lanzhou Yellow River Valley, which has a greater impact on the ambient air quality in Lanzhou.

[Surveillance of Oncomelania hupensis distribution and water levels in Gaoyou sections of the eastern route project of the South-to-North Water Diversion Project following operation of the project]

OBJECTIVE

To understand the distribution of Oncomelania hupensis snails and changes of water levels in Gaoyou sections of the Li Canal following the operation of the eastern route project of the South-to-North Water Diversion Project.

METHODS

The Oncomelania snails were monitored in the river banks and water bodies of Gaoyou sections of the Li Canal by means of systematic sampling combined with environmental sampling as well as collection of the floaters from 2014 to 2019, and the water levels were collected in Gaoyou sections of the Li Canal at the typical hydrological year before the operation of the eastern route project of the South-to-North Water Diversion Project and during the period between 2016 and 2019.

RESULTS

A total area of 235.42 hm² were investigated and a total of 75.8 kg floaters were collected in Gaoyou sections of the Li Canal from 2014 to 2019; however, no snails were found. The water level in Gaoyou sections of the Li Canal was predominantly high in the flood season and low in the dry season before the operation of the eastern route project of the South-to-North Water Diversion Project, and the water level was elevated in the dry season and relatively low in the flood season after the operation of the project.

CONCLUSIONS

Following the operation of the eastern route project of the South-to-North Water Diversion Project, the original river bank that is characterized by "land in winter and water in summer" has changed in Gaoyou sections of the Li Canal, which is not favorable for snail breeding.

[Does age affect the hidden blood loss of elderly intertrochanteric fracture patients fixed with combined external fixator?]

Objective: To evaluate the postoperatively hidden blood loss of elderly intertrochanteric fracture patients fixed with combined external fixator, and to explore the correlation between hidden blood loss and age. Methods: A retrospective analysis was conducted on 60 elderly intertrochanteric fracture patients who were admitted to the Department of Orthopedics of Hebei Provincial Hospital from January 2016 to May 2019. All the fractures were fixed with combined external fixators. The patients were divided into two groups according to the age: there were 31 cases in group A (60-80 years old) and 29 cases in group B (≥80 years old). The Gross equation and the Nandler formula were used to evaluate the amount of hidden blood loss based on changes in hematocrit (Hct) at the day preoperatively, 3 days postoperatively and the weight. The data were compared between the two groups by independent-sample t test. Results: The decreased Hct, hemoglobin(Hb) and the dominant blood loss and hidden blood loss in group A and B was 3.4%±1.7%, (13±7) g/L, (25±6) ml, (186±7) ml and 3.8%±1.2%, (13±3) g/L, (24±8) ml, (194±7) ml, respectively. There was no significant differences in the dominant and hidden blood loss between the groups (t=0.309, 0.883, both P>0.05). Conclusion: The age doesn't affect the hidden blood loss in elderly intertrochanteric fracture patients fixed with combined external fixator, which indicated that the operation is safe and reliable for such patients.

[Formation Potential of Ozone and Secondary Organic Aerosol of VOCs from Fossil Fuel Combustion in Lanzhou City]

With the rapid development of China's industry and the acceleration of urbanization, the massive use of fossil fuels has increased the concentration of air pollutants such as sulfur dioxide, particulate matter, and volatile organic compounds (VOCs) in the cities. However, there is little research on the environmental impact of volatile organic compounds from fossil fuel combustion emissions. In this paper, ozone formation potential(OFP)and secondary organic aerosol formation potential (SOAFP) of VOCs from fossil fuel combustion in Lanzhou city were calculated. The OFP and SOAFP of the cement industry were the largest, representing 45.3% and 50.9%, respectively, followed by brick and tile industries. However, when the calculations were based on tons of standard coal equivalent, the largest contributors to OFP and SOAFP of VOCs emitted from combustion were the brick and tile industries, and the smallest was the natural gas industry. VOCs from fossil fuel combustion of power plants and industry enterprises in the Xigu District are the main contributors to the OFP and SOAFP in the urban district of Lanzhou city. The contribution rates of the aromatic hydrocarbons from fossil fuel to OFP and SOAFP account for 40.0% and 67.2%, respectively. Aromatic hydrocarbons are also the main component in the top 10 species that contribute to OFP and SOAFP. The mass ratio of OFP and SOAFP per VOCs from fossil fuel combustion (2.58 t·t^-1, 3.16 kg·t^-1) is larger than those from biomass combustion (2.22 t·t^-1, 1.38 kg·t^-1).

[Analysis of screening strategy of group B streptococcus in the third trimester and its influence on pregnancy outcome]

Objective: To investigate the screening strategy of group B streptococcus (GBS) in the reproductive tract of women in the third trimester and analyze its impact on pregnancy outcome. Methods: A total of 85 461 pregnant women in 35-37 weeks of gestation from Bao'an Maternity and Child Health Hospital, Jinan University from January 2011 to June 2018 were enrolled. They were divided into 3 periods according to different GBS screening strategies, the unscreened period included 31 384 cases (36.72%), 33 267 cases (38.93%) were included in partial screening period, 20 810 cases (24.35%) were included in screening period. All GBS screening positive pregnant women were given intrapartum antibiotic prophylaxis (IAP). The impact on pregnancy outcomes, and the impact of different GBS collection transport and culture methods on the positive rate of GBS screening were analyzed. Results: (1) The incidence of neonatal early onset GBS disease (EOGBSD) in unscreened period was 0.03% (11/31 773), in partial screening period was 0.02%(6/33 887), and in screening period, the incidence of neonatal EOGBSD decreased to 0, the difference was statistically significant (χ(2)=7.86, P=0.02).(2) The incidence of hematogenous infection of GBS in pregnant women was 0.02%(6/33 887) in partial screening period, and there was none in screening period, there was no significant difference (adjusted χ(2)=3.75, P=0.05). (3) In the screening period, the positive rate of GBS was 14.08%(2 719/19 306), which was significantly higher than the positive rate of GBS in the partial screening period (11.48%, 2 058/17 920; χ(2)=56.12, P=0.00). (4) Antibiotic sensitivity tests of 4 777 GBS strains showed that the antibiotics with higher resistance rate were tetracycline (81.52%, 3 896/4 777), erythromycin (66.59%, 3 181/4 777), and clindamycin (64.31%, 3 072/4 777). The combination of erythromycin, clindamycin and tetracycline was the most common resistant pattern, accounting for 48.80% (2 331/4 777). No penicillin, ceftriaxone or vancomycin resistant strains was found. Conclusions: GBS screening strategy in different regions could combine the local neonatal EOGBSD incidence rate, maternal GBS colonization rate, and the socioeconomic factors to determine whether universal GBS screening or screening for high-risk maternal women. GBS screening positive rate is related to the population, scope of the investigation, the sample collection, delivery and culture methods. The multi-drug resistance rate of GBS is high.

[Inventory and Spatiotemporal Distribution of Ammonia Emission from Agriculture and Animal Husbandry in Lanzhou City]

After obtaining data on the activity of agriculture and animal husbandry by field investigation and from statistical data, an inventory of ammonia emission from agriculture and animal husbandry in Lanzhou was established based on literature investigation to determine the emission factors. The emission factor related to the application of nitrogen fertilizer was calculated using the NARSES model. The spatiotemporal distribution of the amount of ammonia emission was also analyzed. The total amount of ammonia emission from agriculture and animal husbandry was 9356.90 t. Among this emission, the amount from livestock and poultry was 7584.03 t, accounting for 81.05%. Yongdeng County was the region with the largest amount of ammonia emission, which was 2820.59 t, accounting for 30.14%. Considering the sharing rate of ammonia emissions in all districts and counties, the sharing rates of livestock and poultry were between 65.83% and 97.38%; and the sharing rates for nitrogen fertilizer application were between 2.27% and 28.66%. From the perspective of spatial distribution, the sources of ammonia emissions from agriculture and animal husbandry were mainly concentrated in the northwest and central parts of Gaolan County, the southeast of Honggu District, the east and west of Qilihe District, and the east of Yuzhong County. From the perspective of temporal distribution, the ammonia emissions from livestock and poultry were higher from April to September. The emission from nitrogen fertilizer application was higher from March to September, except in August.

[Emissions Inventory of Smoldering Chinese Kangs and Their Contribution to PM2.5 Pollution in Lanzhou City]

Considering regional differences in economic development, the activity level of smoldering Chinese kangs was confirmed by surveys in typical areas in Lanzhou City. An emissions inventory of smoldering Chinese kangs in Lanzhou City in 2016 was established using the emissions factor approach. The emissions amounts of SO₂, NO_x, NH₃, CO, volatile organic compounds (VOCs), PM₁₀, PM_2.5, organic carbon (OC) and elemental carbon (EC) were 340.8, 201.8, 106.0, 36628.2, 4997.2, 6070.3, 5645.1, 1089.3, and 1233.1 t·a^-1, respectively. Emissions amounts were allocated by spatial and temporal characteristics. The emissions were concentrated from November to mid-April of the following year. Spatially, there were significant differences in emissions at different economic levels. The high value areas of emissions were mainly concentrated in the southern part of Yuzhong, central Yongdeng, and south of Qilihe. The weather research and forecasting with chemistry (WRF-Chem) model was used to determine the average contribution of smoldering Chinese kangs to PM_2.5 concentration in Lanzhou City during the heating season. The simulation results were improved after applying the emissions inventory. The average PM_2.5 concentration at Lanyuan Hotel (in the city) and Yuzhong Station (in the countryside) increased 32 μg·m^-3 and 34 μg·m^-3 in the simulation, respectively, and the corresponding rates of pollution contribution were 37.6% and 49.2%. Thus, researching and enacting scientific control measures for smoldering Chinese kang pollutants is significant to improving regional air quality.

[Facial symmetry after conservative treatment of unilateral condylar fracture in children: a three-dimensional study]

Objective: To investigate the influence of condylar fractures on the growth of condylars after conservative treatments by three-dimensional measurement. Methods: Twenty three children with unilateral condylar fracture followed-up for at least 1 year in Shanghai Ninth People's Hospital were included from June 2016 to March 2017. CT scans were performed for each patient. Three-dimensional virtual skulls were reconstructed and measuring points were defined with Simplant 11.04 software. The depth of glenoid fossa, height of articular eminence, width, height and depth of condylar, deviation of pogonion were measured. Statistical analyses were conducted to assess difference between the bifid group and the normal group. Results: No difference was observed in the vertical position of crest of the articular eminence between two groups (P=0.110). The vertical position of roof of the glenoid fossa in bifid side was significantly superior than the one in normal side (P=0.010). Bifid side had a shorter (P=0.002) and wider(P=0.002) condylar than normal side did. No difference was observed in the depth of condylar between two groups (P=0.071). The average deviation of pogonion was (0.69±1.75) mm (P=0.072) from sagittal plan. Conclusions: This short-termed study indicates that children's growth potential of condylar is under average after conservative treatments. Because the bone hyperosteogeny of glenoid fossa compensates the hypotrophy of condylar, no deviation of pogonion is detected.

Transcriptome characterization of HPG axis from Chinese sea perch Lateolabrax maculatus

Here the transcriptome and differential gene expression in the adult brain and gonads of the Chinese sea perch Lateolabrax maculatus were reported. A total of 78 256 909 clean reads were generated from the adult brain, ovary and testis by using the Illumina HiSeq2000 platform and assembled into 274 909 contigs. A total of 31 683 unigenes were annotated based on sequence similarity and 20 702 unigenes were found to exhibit 8237 gene ontology terms and 3888 signal pathways. Transcripts of 26 623 unigenes were present in all of the tissues, whereas pairwise comparisons revealed that 671/367, 496/315 and 1668/580 unigenes were up-down regulated by at least two-fold between the brain and ovary, ovary and testis and brain and testis, respectively. Homology search led to the identification of reproduction-associated genes of the brain-gonad axis, including those involved in sex differentiation and maintenance. The data provided an integrated and comprehensive transcriptome resource for L. maculatus, which could be used for further research on hypothalamus-pituitary-gonad axis gene function, reproduction regulation and sex-biased gene expression.

Stimulus-induced pacemaker activity in interstitial cells of Cajal associated with the deep muscular plexus of the small intestine

BACKGROUND

The ICC-DMP have been proposed to generate stimulus-dependent pacemaker activity, rhythmic transient depolarizations, that take part in orchestrating segmentation and clustered propulsive motor patterns in the small intestine. However, little is known about the fundamental properties of ICC-DMP.

METHODS

This study was undertaken to increase our understanding of intrinsic properties of the ICC-DMP through calcium imaging and intracellular electrical recordings.

KEY RESULTS

Without stimulation, most ICC-DMP were quiescent. In some preparations ICC-DMP generated rhythmic low-frequency calcium oscillations (<10 cpm) with or without high frequency activity superimposed (>35 cpm). Immunohistochemistry proved the existence of NK1R on the ICC-DMP and close contacts between ICC-DMP and substance P-positive nerves. Substance P (25 nM) induced low-frequency calcium oscillations that were synchronized across the ICC-DMP network. Substance P also induced low frequency rhythmic transient depolarizations (<10cpm) in circular muscle cells close to the ICC-DMP. An intracellular recording from a positively identified ICC-DMP showed rhythmic transient depolarizations with superimposed high frequency activity. To investigate if quiescent ICC-DMP were chronically inhibited by nitrergic activity, nNOS was inhibited, but without effect.

CONCLUSIONS & INFERENCES

Substance P changes non-synchronized high frequency flickering or quiescence in ICC-DMP into strong rhythmic calcium transients that are synchronized within the network; they are associated with rhythmic transient depolarizations within the same frequency range. We hypothesize that Substance P, released from nerves, can evoke rhythmicity in ICC-DMP, thereby providing it with potential pacemaker activity.

Design of Hydrogen Storage Alloys/Nanoporous Metals Hybrid Electrodes for Nickel-Metal Hydride Batteries

Nickel metal hydride (Ni-MH) batteries have demonstrated key technology advantages for applications in new-energy vehicles, which play an important role in reducing greenhouse gas emissions and the world's dependence on fossil fuels. However, the poor high-rate dischargeability of the negative electrode materials-hydrogen storage alloys (HSAs) limits applications of Ni-MH batteries in high-power fields due to large polarization. Here we design a hybrid electrode by integrating HSAs with a current collector of three-dimensional bicontinuous nanoporous Ni. The electrode shows enhanced high-rate dischargeability with the capacity retention rate reaching 44.6% at a discharge current density of 3000 mA g(-1), which is 2.4 times that of bare HSAs (18.8%). Such a unique hybrid architecture not only enhances charge transfer between nanoporous Ni and HSAs, but also facilitates rapid diffusion of hydrogen atoms in HSAs. The developed HSAs/nanoporous metals hybrid structures exhibit great potential to be candidates as electrodes in high-performance Ni-MH batteries towards applications in new-energy vehicles.

Magnetic mediation effect of a C impurity in a Mn-doped Zn₁₂O₁₂ nanocluster: a case of multiple exchange interactions

The stability and exchange interaction mechanism of a doped Zn12O12 cluster with Mn and C atoms were investigated by first-principles calculations. For the Mn-doped Zn12O12 cluster, it is identified that a superexchange interaction deriving the hybridization between the Mn 3d(2/x)-2/y and O 2p(xy) orbitals dominates the Mn(↑)-Mn(↓) antiferromagnetic coupling, although a direct exchange interaction deriving the Mn-Mn bonding is also found. In order to turn the Mn spin state in the Mn-doped Zn12O12 cluster, C doping is undertaken to change the magnetic interactions of these impurities. It is proved that the C incorporation into the Mn-doped Zn12O12 cluster destroys the short-ranged antiferromagnetic coupling, where multiple exchange interactions take over, including the direct exchange interaction and the kinetic p-d exchange interaction partially due to the geometric distortion and surface effect with dangling bonds (sp(2)-like hybrids). It is concluded that the kinetic p-d exchange interaction plays a dominant role in Mn/C-doped Zn12O12 clusters.

Copper metallization for current very large scale integration

As silicon technology scaling progresses to the 32 nm node or even further, the design on the propagation of electromagnetic signals becomes increasingly appealing due to their unyielding constraints on interconnect delay. Because of its high conductivity and electromigration resistance, Cu is now the interconnect materials in current VLSI. To ensure the signal propagation via the Cu interconnects upon the increasingly reduction in the interconnect width, related issues on Cu interconnects, such as electron scattering at surfaces and grain boundaries, electromigration failure and surface oxidation, still need to be further understood and addressed. Besides this, the performance of low-k dielectrics and reliable barrier structures, which are also much important among the device parts, are required to be further improved to minimize the signal delay and to prevent penetration of different materials, respectively. On the basis of the paper published at Recent Patent on Nanotechnology 2007; 1: 193-209, this review will focus on recent patents and some studies on Cu metallization including Cu interconnect wires, low-k dielectrics and related barrier materials as well as manufacturing techniques in VLSI, which are one of the most essential concerns in microelectronic industry and decide further development of VLSI. This review will benefit for the design of the Cu metallization in the current VLSI.

Electron scattering and electrical conductance in polycrystalline metallic films and wires: impact of grain boundary scattering related to melting point

For electrical conductance in polycrystalline metallic films and wires, the reflection coefficient of electrons at grain boundaries is explored and found to be proportional to the square root of the melting points of metals. As validated by available experimental results, this exploration enables classical models to take an essential role in theoretically predicting the electrical conductance of low-dimensional metals. One thus sees that the mechanism dominating the suppression of electrical conductance is transformed from the surface scattering into the grain boundary scattering as the ratio of film thickness (or wire diameter) to grain size rises. Furthermore, the impact of grain boundary scattering becomes less important for metals with lower melting points.

Analysis of genetic structure and relationship among nine indigenous Chinese chicken populations by the Structure program

The multi-locus model-based clustering method Structure program was used to infer the genetic structure of nine indigenous Chinese chicken (Gallus gallus) populations based on 16 microsatellite markers. Twenty runs were carried out at each chosen value of predefined cluster numbers (K) under admixture model. The Structure program properly inferred the presence of genetic structure with 0.999 probabilities. The genetic structure not only indicated that the nine kinds of chicken populations were defined actually by their locations, phenotypes or culture, but also reflected the underlying genetic variations. At K = 2, nine chicken populations were divided into two main clusters, one light-body type, including Chahua chicken (CHA), Tibet chicken (TIB), Xianju chicken (XIA), Gushi chicken (GUS) and Baier chicken (BAI); and the other heavy-body type, including Beijing You chicken (YOU), Xiaoshan chicken (XIA), Luyuan chicken (LUY) and Dagu chicken (DAG). GUS and DAG were divided into independent clusters respectively when K equaled 4, 5, or 6. XIA and BIA chicken, XIA and LUY chicken, TIB and CHA chicken still clustered together when K equaled 6, 7, and 8, respectively. These clustering results were consistent with the breeding directions of the nine chicken populations. The Structure program also identified migrants or admixed individuals. The admixed individuals were distributed in all the nine chicken populations, while migrants were only distributed in TIB, XIA and LUY populations. These results indicated that the clustering analysis using the Structure program might provide an accurate representation of the genetic relationship among the breeds.

Synthesis of hierarchical pure ZnO nanostructures with controllable morphology

Hierarchical pure ZnO nanostructures with controllable morphology were synthesized by two-step oxygen-controlled thermal evaporation method without any catalyst. Zn nanowires with little oxidation were deposited firstly on Si substrates located at the low temperature area at step one. The morphology of hierarchical ZnO nanostructures can be effectively modulated at step two by oxygen flow rate, taking advantage of the controllable oxidation rate of Zn and concentration of ZnO(x) under various oxygen supplies. Transmission electron microscope images and corresponding selected area electron diffraction patterns suggest that low oxygen supplementation causes the epitaxial growth of nanorods from the surface of the Zn nanowire, while high oxygen flow rate will lead to the preferential growth of nanorods along the [001] orientation. Room-temperature photoluminescence measurements demonstrate that the variety of nanostructures can cause the variation of the ultraviolet to green peak intensity ratio, suggesting that the controlled morphologies can be used to modulate the optical properties of ZnO nanostructures.

Chemical conversion synthesis and optical properties of metal sulfide hollow microspheres

A facile chemical conversion method has been demonstrated to prepare various metal sulfide hollow microspheres. The present strategy utilizes the large difference in solubility between ZnS and other metal sulfides (Ag2S, PbS, CuS, Cu2S, Bi2S3, and Sb2S3) for the effective transformation and shows mild growth conditions and good reproducibility. The morphology, structure, and composition of the yielded hollow nanostructures have been confirmed by transmission electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction measurements. The optical properties of the metal sulfide hollow microspheres have been systematically investigated by absorption, micro-Raman, and photoluminescence spectroscopy. The results demonstrate that these metal sulfide hollow microspheres possess good optical quality with tunable band gaps and luminescence properties, which indicate their broad potential applications. This simple chemical conversion technique can be further extended to the synthesis of other semiconductors with various morphologies.

Nature of solidification of nanoconfined organic liquid layers

A simple model is established for solidification of a nanoconfined liquid under nonequilibrium conditions. In terms of this model, the nature of solidification is the conjunct finite size and interface effects, which is directly related to the cooling rate or the relaxation time of the undercooled liquid. The model predictions are consistent with available experimental results.

A rat model of chronic allograft liver rejection

INTRODUCTION

The aim of this study was to develop a rat model of chronic irreversible rejection, which is a major causes of late graft loss and retransplantation after orthotopic liver allotransplantation.

METHODS

Allogeneic liver transplantation was performed in a rat combination of Dark Agouti (DA) to Brown Norway (BN). Group A was left without treatment, group B received cyclosporine' (CsA; 1 mg/kg/d) and group C, CsA (4 mg/kg/d). Animals were followed for 6 months. Liver tissue was harvested to construct a time course of histological changes after liver transplantation using histopathological and morphometric techniques. We compared the total histological score of rejection activity index and survival rates.

RESULTS

In untreated animals, irreversible acute rejection developed, all animals died within 15 days. In the low-dose CsA group, all animals that survived more than 30 days developed moderate to severe manifestations of chronic liver rejection, with graft infiltration, ductular damage or proliferation, obliterative arteriopathy, and liver fibrosis. No apparent histological alterations were observed in group C. Survival analysis showed significant differences between the three groups.

CONCLUSIONS

In the rat strain combination of DA --> BN with low-dose immunosuppression, early mild inflammation was followed by the development of chronic rejection.

[HLA-DRB1 gene polymorphism of Naxi ethnic group of Yunnan Province, China and its ethnological evolution analysis]

The HLA-DRB1 gene polymorphism of Naxi ethnic group of Yunnan Province, China was investigated for the first time using high resolution PCR-SBT method, which is based on sequences of HLA-DRB1 Intron 1 and Intron 2 with our improvement. From 60 individuals of Naxi 37 DRB1 alleles were detected. The distribution of allele frequencies is evenly spread for most of alleles detected in Naxi. However, the gene frequency for HLA-DRB1 * 12021 is 17.50%. The other common alleles (> 5%) were HLA-DRB1 * 1404(7.50%), 1504(5.83%), 04051(5.83%), 08032(5.83%), 09012(5%), 03011(5%), and they covered 35% of the total alleles detected from Naxi, and 52.49% after adding the frequency of HLA-DRB1 * 12021. HLA-DRB1 * 0305, 0438, 1123, 1132, 1310, 0812 were detected in Chinese for the first time, and were very rare in other ethnic groups worldwide. Using the HLA-DRB1 gene frequencies of various ethnic groups, we constructed the phylogenetic tree by Fitch-Margoliash and Least-Squares Distance Methods and Cavalli-Sforza's chord measure of genetic distance. In our dendrogram, the South China populations were clustered together, and Siberian, Japanese and Minority of North China were clustered together, in which two big clusters we thought represented the ancient Southern and Northern Mongolian. Our results showed Naxi was clustered with Lahu and Yao ethnic groups, which were in the cluster of South China population. Obviously Naxi belongs to the South China ethnic groups and can't trace its origin from northern ethnic groups with the HLA-DRB1 genetic data. But based on Naxi's historical folklore, it was down to Southern China from Northwest China. The preliminary analysis about its origin conundrum was discussed in this paper based on our genetic data in relationship with its history and ethnology studies.

[Effect of alcohol extract of Cornus officinalis Sieb. et Zucc on GLUT4 expression in skeletal muscle in type 2 (non-insulin-dependent) diabetic mellitus rats]

OBJECTIVE

Based on its effects of decreasing postprandial plasma glucose and increasing insulin level in non-insulin-dependent diabetic mellitus (NIDDM) rats, we studied the effects of Alcohol extract of Cornus officinalis Sieb. et Zucc on the GLUT4 expression in NIDDM model rats.

METHOD

The rat model of NIDDM was made. The animals were divided into three groups(six for each group): group I: control; group II: NIDDM model; group III: NIDDM model + Cornus officinalis Sieb. et Zucc. The drug was given orally to animals one time a day, uninterrupted for a month. The GLUT4 mRNA and its protein expression in skeletal muscle were observed with Northern blot and Western blot method, respectively.

RESULT

The GLUT4 mRNA expression in skeletal muscle was decreased remarkably in NIDDM rats (P < 0.01, compared to control group). Alcohol extract of Cornus officinalis Sieb. et Zucc increased GLUT4 mRNA expression in NIDDM rats(P < 0.01), compared to NIDDM model group). The result of GLUT4 protein expression was similar to GLUT4 mRNA expression.

CONCLUSION

This experiment demonstrated that alcohol extract of Cornus officinalis Sieb. et Zucc can increase GLUT4 mRNA and its protein expression in NIDDM rats through promoting proliferation of islet and increasing postprandial secretion of insulin and therefore accelerate glucose transport.

Discovery of a series of nonpeptide small molecules that inhibit the binding of insulin-like growth factor (IGF) to IGF-binding proteins

Insulin-like growth factors (IGF-I and II) play an important role in metabolic and mitogenic activities through stimulation of the IGF-I receptor on the cell surface. Although the concentration of IGF in blood and cerebrospinal fluid is quite high (>100 nM), this large pool of IGF is biologically inactive because of its association with six distinct binding proteins, which form high-affinity complexes with IGF. Thus, inhibitors of IGF-binding proteins (IGFBPs), especially IGFBP-3, could potentially alter the distribution between the "free" and "bound" forms of IGF and thereby elevate biologically active IGF-I to exert a beneficial effect on those patients with diseases that respond to the application of exogenous IGF-I. Whereas IGF-I peptide variants, which bind to IGFBPs but not the IGF-I receptor, have been shown to be potent IGF/IGFBP inhibitors, small molecule nonpeptide IGF/IGFBP inhibitors have the potential advantages of oral bioavailability and flexible dosing regimen. Here we report the discovery of several isoquinoline analogues, exemplified by 1 and 2, which bind IGFBP-3 as well as other IGFBPs at low nanomolar concentrations. More importantly, both compounds were shown to be able to release biologically active IGF-I from the IGF-I/IGFBP-3 complex. These results point to the feasibility of developing orally active therapeutics to treat IGF-responsive diseases by optimization of the lead molecules 1 and 2.

Identification of a nonpeptide ligand that releases bioactive insulin-like growth factor-I from its binding protein complex

Insulin-like growth factor-I (IGF-I) has both metabolic and mitogenic activities mediated through interaction with the type 1 IGF receptor. The circulation of IGF-I in blood and interstitial fluid is not free but bound mostly to a family of six high affinity IGF-binding proteins, which form stable complexes with IGF and neutralize its bioactivity. Therefore, displacement of this large pool of endogenous IGF from the binding proteins could elevate "free" IGF levels to elicit beneficial effects in diabetes and other IGF-responsive diseases comparable with those produced by administration of exogenous IGF-I. We report here the identification of a nonpeptide ligand NBI-31772, which displaces IGF-I from all six IGF-binding proteins at low nanomolar concentrations from screening of the in-house chemical libraries. Furthermore, the released free IGF-I was shown to be biologically active in an in vitro bioassay. Thus, NBI-31772 could serve as a valuable lead molecule for the design of novel therapeutics to treat diabetes and other IGF-responsive diseases.

A cytoplasmic RNA vector derived from nontransmissible Sendai virus with efficient gene transfer and expression

We have recovered a virion from defective cDNA of Sendai virus (SeV) that is capable of self-replication but incapable of transmissible-virion production. This virion delivers and expresses foreign genes in infected cells, and this is the first report of a gene expression vector derived from a defective viral genome of the Paramyxoviridae. First, functional ribonucleoprotein complexes (RNPs) were recovered from SeV cloned cDNA defective in the F (envelope fusion protein) gene, in the presence of plasmids expressing nucleocapsid protein and viral RNA polymerase. Then the RNPs were transfected to the cells inducibly expressing F protein. Virion-like particles thus obtained had a titer of 0.5 x 10(8) to 1. 0 x 10(8) cell infectious units/ml and contained F-defective RNA genome. This defective vector amplified specifically in an F-expressing packaging cell line in a trypsin-dependent manner but did not spread to F-nonexpressing cells. This vector infected and expressed an enhanced green fluorescent protein reporter gene in various types of animal and human cells, including nondividing cells, with high efficiency. These results suggest that this vector has great potential for use in human gene therapy and vaccine delivery systems.

Progress towards the development of non-peptide orally-active gonadotropin-releasing hormone (GnRH) antagonists: therapeutic implications

Gonadotropin-releasing hormone (GnRH) is a decapeptide (pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly.NH2) which is produced from a precursor polypeptide in hypothalamic neurons and secreted in a pulsatile fashion to stimulate the secretion of LH and FSH via its interaction with a cognate receptor on gonadotropes. Low doses of the native peptide delivered in a pulsatile manner to mimic that found in the hypothalamic portal vessels restore fertility in hypogonadal patients, and are also effective in treating cryptorchidism and delayed puberty. Administration of high doses of GnRH, or agonist analogues, causes desensitization of the gonadotrope with consequent decline in gonadal gametogenesis and steroid and peptide hormone synthesis. This phenomenon finds extensive therapeutic application in clinical medicine in a wide spectrum of disease (Table 1). In addition, GnRH analogues have promise as new generation male and female contraceptives in conjunction with steroid hormone replacement. GnRH antagonists inhibit the reproductive system through competition with endogenous GnRH for the receptor and, in view of their rapid effects, are being increasingly used for the above mentioned applications. The peptide agonists and antagonists currently available require parenteral administration, typically in the form of long-acting depots. A new generation of non-peptide GnRH antagonists are beginning to emerge which should allow oral administration and, therefore, may provide greater flexibility of dosing, lower costs and increased patient acceptance.

In situ investigation of Fas/FasL expression in chronic hepatitis B infection and related liver diseases

To evaluate Fas/FasL expression in hepatitis B virus-related chronic liver disease, liver biopsies from 44 such cases were studied immunohistochemically. FasL was detected in the infiltrating lymphocytes and both FasL and Fas were found in the hepatocytes. The Fas and FasL-positive cells were mostly found at the advancing edges of interphase hepatitis, and Fas/FasL expression was closely correlated with the inflammatory activity. Unexpectedly, FasL was also expressed in liver cirrhotic nodules, particularly in those with hepatocellular carcinoma with or without inflammation. These results suggest that the factors which induce hepatocyte transformation might also trigger FasL expression and promote FasL/Fas-mediated apoptosis.

The correlation of Ureaplasma urealyticum infection with infertility

A prevalence study of Ureaplasma urealyticum (UU) infection of the male genital tract was carried out in Shanghai between March 1992 and June 1995. Significantly higher frequency of UU infection was found among infertile males (549/1416) as compared to fertile controls (34/375). Examination of 8 specimens each from infertile men and fertile subjects by electron microscopy, immunogold and immunofluorescence techniques, demonstrated adhesion of Ureaplasma urealyticum to the membrane of spermatozoa and exfoliated germ cells. In addition, gold particles on Ureaplasma urealyticum were found to be adhered to the sperm surface in 4 of the 8 samples. Strong specific anti-UU fluorescence was detected in 6 of 8 samples, mainly on the midpieces and post-acrosomal regions of the spermatozoa. To further study the effects of Ureaplasma urealyticum on fertility, 47 male Sprague-Dawley (SD) rats were infected artificially with Ureaplasma urealyticum serotype 8 (T960). Morphological changes in the seminiferous tubules were observed 3-5 weeks after inoculation in the sacrificed animals. Dramatic impairment of spermatogenesis of both testes was found in 11 rats. Mating experiment confirmed infertility in 12 of 40 rats. Offsprings of the infected rats were significantly smaller than those of controls in terms of prenatal weights and birthweights.

Matrix-assisted laser desorption/ionization for sequencing single-stranded and double-stranded DNA

The DNA sequence of a single-stranded and double-stranded template was determined. The templates were sequenced using the chain termination method and cycle sequencing method and detected by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The sequencing products were analyzed successfully without the laborious and expensive methods for removal of the template. Direct sequencing of the double-stranded template was achieved with minimal post-reaction purifications, which could be extremely important for mutation analysis and clinical diagnosis. A systematic study of the mechanisms and kinetics of sequencing reactions was also performed. The details of this analysis and directions for future improvements of the quality of sequencing are presented.