[HIV infection rate, high-risk behavior and pre-exposure prophylaxis/post-exposure prophylaxis in men who have sex with men in Beijing]

Objective: To understand the incidence of HIV infection, high risk behaviors and pre-exposure prophylaxis/post-exposure prophylaxis (PrEP/PEP) utilization in men who have sex with men (MSM) in Beijing. Methods: Sample size was estimated to be 1 227 persons and 207 person year respectively in the survey and the cohort by using Epi Info 7.0 software. Using convenient sampling method, MSM were recruited by using Wechat app. Questionnaire was completed online to collect the information about demographic characteristics, high risk behavior, and utilization of PrEP/PEP of the MSM. MSM collected dry blood spot (DBS) samples by themselves, and mailed the DBS samples to laboratory for HIV nucleic acid testing. Open cohort was established and those with HIV negative nucleic acid testing results were followed up. Non-conditional binary logistic regression method was used to identify the associated factors for high risk anal sex in the last month and having multiple homosexual partners in the last month. Results: A total of 1 147 MSM were recruited, and follow up for 236 person years was conducted in 956 MSM with negative HIV nucleic acid testing results. The detection rate of new HIV infection was 1.3 per 100 person-years (3/236). During the last month, the proportions of consistent condom use in anal sex and oral sex were 50.7% (238/469) and 4.9% (23/469). In the MSM, 5.9% (43/723) had sex with HIV positive partners in the last month. 9.8% (103/1 049) used PrEP, and 8.7% (91/1 049) used PEP. The proportion of consistent condom use in PrEP and PEP were 34.3% (24/70) and 72.2% (39/54) respectively. Logistic regression analysis revealed that compared with those who used no PrEP/PEP, those who used PrEP/PEP were more likely to have unprotected anal sex in the last month (aOR=3.16, 95%CI:1.45-7.18), and more likely to have multiple homosexual partners in the last month (aOR=2.64, 95%CI:1.19-6.30), and compared with those who used no Rush Popper or drugs in the last month, those who used Rush Popper or drugs in the last month were more likely to have unprotected anal sex in the last month (aOR=2.34, 95%CI:1.67-3.30), and more likely to have multiple homosexual partners (aOR=2.42,95%CI:1.76-3.33). Conclusions: It is necessary to strengthen the health education to promote condom use and introduce the harm of drug use in MSM. In PrEP and PEP services, it is still necessary to suggest consistent condom use for MSM.

[Metagenomic next-generation sequencing of plasma for the identification of bloodstream infectious pathogens in severe aplastic anemia]

Objective: To analyze the diagnostic value of cell-free plasma metagenomic next-generation sequencing (mNGS) pathogen identification for severe aplastic anemia (SAA) bloodstream infection. Methods: From February 2021 to February 2022, mNGS and conventional detection methods (blood culture, etc.) were used to detect 33 samples from 29 consecutive AA patients admitted to the Anemia Diagnosis and Treatment Center of the Hematology Hospital of the Chinese Academy of Medical Sciences to assess the diagnostic consistency of mNGS and conventional detection, as well as the impact on clinical treatment benefits and clinical accuracy. Results: ①Among the 33 samples evaluated by mNGS and conventional detection methods, 25 cases (75.76%) carried potential pathogenic microorganisms. A total of 72 pathogenic microorganisms were identified from all cases, of which 65 (90.28%) were detected only by mNGS. ②All 33 cases were evaluated for diagnostic consistency, of which 2 cases (6.06%) were Composite, 18 cases (54.55%) were mNGS only, 2 cases (6.06%) were Conventional method only, 1 case (3.03%) was both common compliances (mNGS/Conventional testing) , and 10 cases (30.3%) were completely non-conforming (None) . ③All 33 cases were evaluated for clinical treatment benefit. Among them, 8 cases (24.24%) received Initiation of targeted treatment, 1 case (3.03%) received Treatment de-escalation, 13 cases (39.39%) received Confirmation, and the remaining 11 cases (33.33%) received No clinical benefit. ④ The sensitivity of 80.77%, specificity of 70.00%, positive predictive value of 63.64%, negative predictive value of 84.85%, positive likelihood ratio of 2.692, and negative likelihood ratio of 0.275 distinguished mNGS from conventional detection methods (21/12 vs 5/28, P<0.001) . Conclusion: mNGS can not only contribute to accurately diagnosing bloodstream infection in patients with aplastic anemia, but can also help to guide accurate anti-infection treatment, and the clinical accuracy is high.

[Clinical characteristics and CT findings of Pneumocystis Jirovecii pneumonia in 46 cases with hematological diseases]

Objective: To summarize the original CT features of Pneumocystis Jirovecii pneumonia in patients with hematological diseases. Methods: A retrospective analysis was carried out in 46 patients with proven pneumocystis pneumonia (PJP) in the Hospital of Hematology, Chinese Academy of Medical Sciences between January 2014 and December 2021. All patients had multiple chests CT and related laboratory examinations, imaging typing were conducted based on the initial CT presentation, and the distinct imaging types were analyzed against the clinical data. Results: In the analysis, there were 46 patients with proven pathogenesis, 33 males, and 13 females, with a median age of 37.5 (2-65) years. The diagnosis was validated by bronchoalveolar lavage fluid (BALF) hexamine silver staining in 11 patients and clinically diagnosed in 35 cases. Of the 35 clinically diagnosed patients, 16 were diagnosed by alveolar lavage fluid macrogenomic sequencing (BALF-mNGS) and 19 by peripheral blood macrogenomic sequencing (PB-mNGS) . The initial chest CT presentation was categorized into 4 types, including ground glass (GGO) type in 25 cases (56.5%) , nodular type in 10 cases (21.7%) , fibrosis type in 4 cases (8.7%) , and mixed type in 5 cases (13.0%) . There was no substantial discrepancy in CT types among confirmed patients, BALF-mNGS diagnosed patients and PB-mNGS diagnosed patients (χ(2)=11.039, P=0.087) . The CT manifestations of confirmed patients and PB-mNGS diagnosed patients were primarily GGO type (67.6%, 73.7%) , while that of BALF-mNGS diagnosed patients were nodular type (37.5%) . Of the 46 patients, 63.0% (29/46) had lymphocytopenia in the peripheral blood, 25.6% (10/39) with positive serum G test, and 77.1% (27/35) with elevated serum lactate dehydrogenase (LDH) . There were no great discrepancies in the rates of lymphopenia in peripheral blood, positive G-test, and increased LDH among different CT types (all P>0.05) . Conclusion: The initial chest CT findings of PJP in patients with hematological diseases were relatively prevalent with multiple GGO in both lungs. Nodular and fibrosis types were also the initial imaging findings for PJP.

[Transition rules of cognitive frailty and influencing factors in the elderly in China]

Objective: To understand the transition rules of cognitive frailty and its influencing factors in the elderly in China and provide evidence for the early intervention of cognitive frailty. Methods: Data were retrospectively collected from China Health and Retirement Longitudinal Study with 3 round consecutive survey (2011, 2013, 2015) and the state of the subjects were classified into four categories: robust-normal cognitive, cognitive impairment, physical frailty, and cognitive frailty. A multi-state Markov model was established to explore the transition rules of cognitive frailty and its influencing factors. Results: A total of 3 470 older adults were included, and 350 (10.09%) had cognitive frailty at baseline. After two years, the probability of cognitive frailty in the cognitive impairment population was higher than that in people with physical frailty (31.6% vs. 7.6%). Persons with cognitive frailty were more likely to become physical frailty (29.7% vs. 15.6%). Being women (HR=1.599, 95%CI: 1.058-2.417), comorbidity (HR=3.035, 95%CI: 1.090-8.450), and depression (HR=1.678, 95%CI: 1.153-2.441) were the risk factors associated with cognitive frailty in the elderly, while being educated (HR=2.367, 95%CI: 1.567-3.575) was a protective factor for the transition of cognitive frailty to physical frailty. Conclusions: The prevalence of cognitive frailty is relatively high in the elderly in China. Those with cognitive impairment have a higher probability of cognitive frailty. Gender, education level, comorbidity, and depression are the main influencing factors for the occurrence and transition of cognitive frailty.

[China's countermeasures in the context of Global Tuberculosis Prevention Action]

In order to speed up the expansion of global tuberculosis (TB) preventive treatment (TPT), the WHO released "CALL TO ACTION 2.0 A GLOBAL DRIVE TO SCALE UP TB PREVENTION" in June 2021, calling on governments and other stakeholders to increase investment, expand the TB screening and diagnosis, and accelerate coverage of TB preventive treatment. To ensure reach the targets of TPT committed by Heads of State at the UN High Level Meeting on TB (UN-HLM) in 2018. The author systematically analyzed the current situation, the progress, the necessity and urgency of carrying out TPT in China, and put forward the countermeasures and suggestions of TPT in China.

Nomogram for predicting chylous ascites after right colectomy

BACKGROUND

Chylous ascites following right colectomy has a high incidence which is a critical challenge. At present, there are few studies on the factors affecting chylous ascites after right colectomy and especially after D3 Lymphadenectomy. A predictive model for chylous ascites has not yet been established. Therefore, we created the first nomogram to predict the incidence of chylous ascites after right hemicolectomy.

AIM

To analyze the risk factors for chylous ascites after right colectomy and establish a nomogram to predict the incidence of chylous ascites.

METHODS

We retrospectively collected patients who underwent right hemicolectomy between January 2012 and May 2021 and were pathologically diagnosed with cancer. Multivariate logistic regression was used to analyze the influencing factors of chylous ascites and a nomogram was established. The predictive ability was assessed by the area under the receiver operating characteristic (ROC) curve.

RESULTS

Operative time, the type of operation (standard or extended), the number of lymph nodes retrieved, and somatostatin administration were considered important risk factors. Multivariate logistic regression and nomograms can be used to accurately predict whether chylous ascites occurs. The area under the ROC curve of the model is 0.770. The C-statistic of this model is 0.770 which indicates that it has a relatively moderate ability to predict the risk of chylous ascites.

CONCLUSION

We found a novel set of risk factors, created a nomogram, and validated it. The nomogram had a relatively accurate forecasting ability for chylous ascites after right hemicolectomy and can be used as a reference for risk assessment of chylous ascites and whether to prevent it after surgery.

[Analysis of pathogens and clinical characteristics of bloodstream infection in neutropenic children with hematological malignancies from 2014 to 2018]

目的

探讨儿童血液病患者在中性粒细胞缺乏（粒缺）期发生血流感染时的病原学分布、耐药情况，为该类患者合理使用抗菌药物提供数据支持。

方法

回顾性分析2014年1月至2018年12月中国医学科学院血液病医院收治的儿童血液病患者粒缺期发生血流感染时的临床特征、病原菌分布和药物敏感性数据。

结果

427例儿童血液病患者在粒缺期共发生537次血流感染，30 d全因死亡率为3.7%。其中44.7%例次血流感染的临床特征仅表现为发热，其病原菌以肠杆菌科细菌为主。血流感染常伴口腔黏膜、呼吸道及消化道症状，比例分别为20.7%、20.5%和14.3%。伴不同症状的血流感染病原菌分布不同（χ²=40.561，P=0.001）。共分离出550株病原菌，位于前5位的细菌分别为草绿色链球菌（109株，19.8%）、大肠埃希菌（99株, 18.0%）、表皮葡萄球菌（75株，13.6%）、肺炎克雷伯菌（67株，12.2%）和金黄色葡萄球菌（32株，5.8%）。耐药方面，肠肝菌科细菌及铜绿假单胞菌对于哌拉西林/他唑巴坦、碳青霉烯类药物的耐药率<5%。金黄色葡萄球菌中耐甲氧西林金黄色葡萄球菌（MRSA）的比例为9.7%。

结论

儿童恶性血液病患者粒缺期发生血流感染病原菌革兰阳性球菌与阴性杆菌比例大致相同，提示经验性抗菌药物使用应具有广谱性，常见分离菌耐药性仍处于较低水平，常用的碳青霉烯类、糖肽类、酶抑制剂复合物类药物如哌拉西林/他唑巴坦等仍具有较好效果。

[A preliminary study on molecular target identification of drugs in individualized treatment of malignant solid tumors in children]

Objective: To explore the role of drug-related molecular target identification in the individualized treatment of malignant solid tumors in children. Methods: The clinical data of 40 patients diagnosed with malignant solid tumors from Beijing Tongren Hospital, Capital Medical University, between June 2017 and March 2019 were retrospectively analyzed. Immunohistochemistry, polymerase chain reaction and sequencing methods were used to determine the expression levels and mutations of tumor drug molecular targets, and to compare the efficiency as well as the incidence of toxic side effects of chemotherapy using anti-tumor drugs with various molecular targets. Results: A total of 4 tumor drug-related targets were identified in 40 tumor tissue samples, namely DNA topoisomerase-ⅡA (TOPOⅡA), β(3)-tubulin (Tubulinβ(3)), DNA topoisomerase-Ⅰ(TOPOⅠ) and dihydrofolate reductase gene polymorphisms [DHFR (C829T)]. The effective rates of platinum-based agents, methotrexate, irinotecan, vinblastine and anthracycline for malignant solid tumors in children were 90.0% (36/40), 85.0% (34/40), 70.0% (28/40), 67.5% (27/40), 62.5% (25/40), respectively. The effective rates of chemotherapy with irinotecan, methotrexate, and vinblastine in mesenchymal tumors were 68.9% (20/29), 62.1% (18/29), 68.9% (20/29), respectively, which were considerably higher than 18.2% (2/11), 36.4% (4/11) and 36.4% (4/11) in non-mesenchymal tumors, with significant differences (χ(2)=5.487, 15.345, 17.278, all P<0.05). The effective rate of chemotherapy of platinum-based drugs for non-mesenchymal tumors was 72.3% (8/11), which was significantly higher than 58.6% (17/29) in mesenchymal tumors, and the difference was statistically significant (χ(2)=11.231, P<0.05). The intensity of toxic side effects in order from high to low was anthracycline > platinum > methotrexate > vinblastine > irinotecan. Conclusion: Tumor drug-related molecular targets and the sensitivity of tumors of different origins to the same anti-tumor drug as well as side effects are predicted, which provides a theoretical and clinical basis for individualized treatment of malignant tumors in children.

[Clinical features and laboratory data analysis of Aeromonas bacteremia with hematological diseases]

目的

分析患有血液系统疾病患者气单胞菌血流感染的临床及实验室特征，为该类患者气单胞菌感染的防治提供依据。

方法

回顾性分析中国医学科学院血液病医院2014年1月至2018年12月5年发生气单胞菌血症的血液系统疾病患者，收集患者临床感染特征、菌株耐药性、发生季节、治疗及转归情况等相关信息。

结果

共42例血液病患者发生气单胞菌血流感染，其中39例（92.9%）血流感染发生于粒细胞缺乏（粒缺）期，平均发热时间为4（1~27）d，22例（52.4%）患者症状仅为发热，6例（14.3%）伴消化道症状（腹痛、腹泻、恶心、上消化道出血），8例（19.0%）伴肺部感染，13例（31.0%）伴皮肤软组织感染。7例（16.7%）患者死亡，且均伴皮肤软组织感染。气单胞菌对碳青霉烯类抗菌药物的耐药率为68.3%~70.7%，而对头孢菌素类、喹诺酮类及氨基糖苷类抗菌药物的耐药率均小于10%。

结论

血液系统疾病合并气单胞菌血流感染主要发生在粒缺期，主要以发热为主，当伴有皮肤软组织感染时死亡率高。抗菌药物选择应依据药敏结果，避免使用碳青霉烯类抗菌药物。

[A cross-sectional study on economic burden of pulmonary tuberculosis cases from designated tuberculosis hospital]

Objective: To understand the medical expenditure and related household economic burden of pulmonary tuberculosis (TB) patients receiving full course treatment in designated TB hospitals in China and identify the related factors. Method: A cross-sectional study was conducted in 535 consecutive TB patients receiving TB treatment from April 2017 to June 2017 in 5 designated TB hospitals in eastern and western China selected through stratified cluster sampling. A questionnaire was used to collect the information about patients' social economic characteristics and TB diagnosis and treatment expenditure. Results: The average total medical expenditure for TB treatment was 12 635.5 yuan (RMB), in which the direct medical expenditure accounted for 65.3% of the total. Nearly half of the total medical expenditure occurred in pre-treatment period. The expenditure in pre- treatment period was higher in the patients with low education level, newly treated patients, and initial sputum negative patients. The median (quartile) for the ratio of total medical expenditure to annual household income was 22%(10%-57%). Ordinal logistic regression analysis showed that low-level education background, lower household income, hospitalization and suffering from other chronic disease might increase the ratio of medical expenditure to annual household income. Conclusions: Medical expenditure for full course TB treatment is still high in patients in designated TB hospitals. It is suggested to strengthen the capability building of timely found and referral of TB patients in non- designated hospitals and improve fee reduction and exemption policy for some patients.

[Perianal swabs surveillance cultures of Carbapenem-resistant Enterobacteriaceae(CRE) can be hints for CRE bloodstream infection in patients with hematological diseases]

目的

探讨血液病患者肛周皮肤拭子细菌培养检出耐碳青霉烯类肠杆菌（CRE）对CRE血流感染的预警价值，寻找CRE血流感染的危险因素。

方法

对2016年1月至2017年12月进行肛周皮肤拭子细菌培养的血液病患者分离出CRE的耐药率、患者后期CRE血流感染发生情况及危险因素进行回顾性分析。

结果

2 914例血液病患者进行了肛周皮肤拭子细菌培养，74例检出CRE，其中后期发生CRE血流感染者13例（17.6%）。共分离出CRE 87株（相同患者相同部位去重），包括肺炎克雷伯菌31株、大肠埃希菌43株、阴沟肠杆菌8株、其他肠杆菌科细菌6株。分离出CRE菌株对哌拉西林/他唑巴坦、亚胺培南、美罗培南、阿米卡星、左氧氟沙星、替加环素的耐药率分别为91.9%、74.4%、98.8%、17.6%、74.4%和8.0%。13例发生CRE血流感染患者肛周皮肤拭子与血液中分离株对碳青霉烯类、氨基糖苷类、喹诺酮类及替加环素耐药程度一致率较高。粒细胞缺乏（粒缺）、存在消化道症状、肛周感染持续时间为肛周皮肤CRE阳性患者发生CRE血流感染的独立危险因素（OR值分别为1.10、1.13和1.23，P值分别为0.029、0.005、0.016）。

结论

对血液病患者进行肛周皮肤拭子细菌培养可为后期CRE血流感染提供预警，并可为其提供抗菌药物选择参考；粒缺、伴消化道症状以及肛周感染持续时间长可作为CRE血流感染患者早期识别因素。

[Combination of CT mulitplane 3D reconstruction, radial endobronchial ultrasound and rapid on-site evaluation for diagnosing peripheral solitary pulmonary nodules]

Objective: To evaluate the diagnostic efficiency of combination of CT multiplane 3D reconstruction (CT-3DR), radial endobronchial ultrasound (R-EBUS), and rapid on-site evaluation (ROSE) for peripheral solitary pulmonary nodules (SPN). Methods: A total of 176 patients with peripheral solitary pulmonary nodule were included from the Nanjing Chest Hospital from March 2016 to March 2017. According to different methods, all the patients were divided into four groups: EG (i.e. R-EBUS+Guiding sheath (GS))group, CTE (i.e. CT-3DR+R-EBUS) group, RE (i.e. ROSE+R-EBUS) group, and triad (i.e. CT-3DR+ROSE+R-EBUS) group. Sampling was performed by transbronchial lung biopsy. The diagnostic yield and complications, procedure time and influencing factors in these four groups were retrospectively analyzed. The value of ROSE and combination of CT-3DR+ROSE+R-EBUS in diagnosis for SPN also was evaluated. Results: The diagnostic yield for total SPNs among four groups were 70.5% in EG group, 70.0% in CTE group, 69.0% in RE group and 74.0% in triad group, respectively. There was no significant difference among four groups (all P>0.05). The procedure time of EG group, CTE group, RE group and triad group were (34.0±6.3), (26.6±6.8), (27.2±7.8) and (19.4±5.4) min, respectively. The procedure time was the shortest in triad group compared with the other three groups (all P<0.001) and the time of CTE and RE groups were significantly shorter than the EG group (both P<0.001). The coincidence rates of CT-3DR navigation position with target bronchus were 87.5% in CTE group and 90.0% in triad group with no significant difference between these two groups (P>0.05). The diagnostic yield was higher for SPNs with their major diameter ≥2 cm than those with their major diameter<2 cm in all four groups (all P<0.05). The positive diagnostic yield was higher with ultrasonic probe located within SPN lesion than the probe adjacent to or deviated the lesion in all four groups (all P<0.05). In EG and RE groups, for those SPNs with the distance between the lesion and pleura≥2 cm, the diagnostic yield were higher than those withe the distance<2 cm (P<0.05) but no similar phenomenon was observed in CTE and triad groups. No significant correlation was detected between the diagnostic yield and the density of SPN lesions among four groups (all P>0.05). ROSE was used in RE and triad groups. The coincidence rate of ROSE with histopathology was 82.6% and the value of Kappa was 0.608. The diagnostic sensitivity, specificity, positive predictive value and negative predictive value of ROSE were 0.818, 0.846, 0.931 and 0.647, respectively. Conclusions: CT-3DR navigation and ROSE help to improve the diagnostic efficiency of R-EBUS for SPN. Combination of CT-3DR, R-EBUS and ROSE is of diagnostic value for peripheral SPN and with significant shortening of procedure time.

Ab initio molecular dynamics simulation of the effects of stacking faults on the radiation response of 3C-SiC

In this study, an ab initio molecular dynamics method is employed to investigate how the existence of stacking faults (SFs) influences the response of SiC to low energy irradiation. It reveals that the C and Si atoms around the SFs are generally more difficult to be displaced than those in unfaulted SiC, and the corresponding threshold displacement energies for them are generally larger, indicative of enhanced radiation tolerance caused by the introduction of SFs, which agrees well with the recent experiment. As compared with the unfaulted state, more localized point defects are generated in faulted SiC. Also, the efficiency of damage production for Si recoils is generally higher than that of C recoils. The calculated potential energy increases for defect generation in SiC with intrinsic and extrinsic SFs are found to be higher than those in unfaulted SiC, due to the stronger screen-Coulomb interaction between the PKA and its neighbors. The presented results provide a fundamental insight into the underlying mechanism of displacement events in faulted SiC and will help to advance the understanding of the radiation response of SiC with and without SFs.

Polymorphisms of the ATP1A1 gene associated with mastitis in dairy cattle

Mastitis affects the concentrations of potassium and sodium in milk. Since sodium-potassium adenosine triphosphatase (Na(+), K(+)-ATPase) is critical for maintaining the homeostasis of these two ions, and is involved in cell apoptosis and pathogenesis, we presumed that polymorphism of the ATP1A1 gene, which encodes the bovine Na(+), K(+)-ATPase α1 subunit could be associated with mastitis. The ATP1A1 gene was analyzed in 320 Holstein cows using PCR low ionic strength single-strand conformation polymorphism (PCR-LIS-SSCP) and DNA sequencing methods. A C/A SNP was identified at nucleotide position -15,739 in exon 17 of the ATP1A1 gene, but it did not induce any change in amino acids. We examined a possible association of polymorphism of the ATP1A1 gene with somatic cell score and 305-day milk yields. Individuals with genotype CC in ATP1A1 had significantly lower somatic cell scores and 305-day milk yields than those with genotype CA. We also examined changes in Na(+), K(+)-ATPase activity of red cell membranes. The Na(+), K(+)-ATPase activity was significantly higher in dairy cows with genotype CC compared to the other two genotypes, and the Na(+), K(+)-ATPase activity of the resistant group was significantly higher than that of the susceptible group in dairy cows. We conclude that this polymorphism has potential as a marker for mastitis resistance in dairy cattle.

Treatment of domestic sewage by a metal membrane bioreactor

A submerged flat metal MBR (membrane bioreactor) was used to treat synthetic domestic sewage in this study. The experiment was continued for 270 days and ran under two modes as AMBR (aerobic membrane bioreactor) and A/O-MBR (anoxic/aerobic membrane bioreactor) at a permeate flux of 0.4-1 m³/(m² d). PVA (polyvinyl alcohol) gel beads were added to the aeration tank with a volume ratio of 10% at the end of the A/O-MBR mode. The mean COD and TN removal efficiencies achieved 96.69 and 32.12% under the AMBR mode, and those were 92.17 and 72.44% under the A/O-MBR mode, respectively. SND (simultaneous nitrification and denitrification) occurred at high MLSS (mixed liquor suspended solids) concentration. The metal membranes reduced effluent COD during filtration. The system ran stably for 115 days at a permeate flux of 0.8-1 m³/(m² d) without changing membranes under the AMBR mode, but the membrane filterability decreased gradually under high MLSS or A/O-MBR mode, and the addition of PVA worsened the membrane filterability on the contrary. PSD (particle size distribution) and sludge fractions had evident influence on membrane fouling. The main fouling mechanism was cake formation under the AMBR mode, and that was pore blocking under the A/O-MBR mode.

Real-time imaging and detection of intracranial haemorrhage by electrical impedance tomography in a piglet model

The aim of this study was to use electrical impedance tomography (EIT) to detect and image acute intracranial haemorrhage (ICH) in an animal model. Blood was infused into the frontal lobe of the brains of anaesthetized piglets and impedance was measured using 16 electrodes placed in a circle on the scalp. The EIT images were constructed using a filtered back-projection algorithm. The mean of all the pixel intensities within a region of interest--the mean resistivity value (MRV)--was used to evaluate the relative impedance changes in the target region. A symmetrical index (SI), reflecting the relative impedance on both sides of the brain, was also calculated. Changes in MRV and SI were associated with the injection of blood, demonstrating that EIT can successfully detect ICH in this animal model. The unique features of EIT may be beneficial for diagnosing ICH early in patients after cranial surgery, thereby reducing the risk of complications and mortality.

Enhanced thermal stability of monodispersed silver cluster arrays assembled on block copolymer scaffolds

Triblock copolymer poly(styrene-b-butadiene-b-styrene) (SBS) films with long-range ordered self-assembled nanopatterns are used as templates to selectively adsorb soft-landing silver clusters. Closely spaced cluster arrays with high monodispersity are formed through the confinement of the block copolymer scaffolds, and show a much enhanced thermal stability as compared with the cluster assemblies on the surfaces of covalent amorphous solids, or even on the disordered SBS films. Their morphologies are barely influenced by long time thermal annealing at a temperature as high as 180 degrees C, while in the latter case intense aggregations and coalescences of silver clusters are commonly observed upon annealing. The different thermal stabilities of the cluster assemblies also induce different evolutions of their optical extinction spectra under annealing. This promises a simple way to control the monodispersity and thermal stability of metal cluster assembly via self-assembled block copolymer template.

Clinical and Experimental Effectiveness of Astragali Compound in the Treatment of Chronic Viral Hepatitis B

Chinese herbs are widely used in the treatment of chronic viral hepatitis B. The effectiveness of 2 months' treatment with Astragali compound (AC), containing Radix Astragali and adjuvant components, was studied for the treatment of chronic viral hepatitis in 116 patients; 92 patients were given other drugs in regular clinical use for viral hepatitis (controls). The clinical efficacy of AC was significantly better in AC-treated patients than in controls. Negative seroconversions of hepatitis B virus (HBV) antigen e and HBV DNA were also significantly higher in AC-treated patients than in controls. Of eight duck viral hepatitis B models infected with duck hepatitis B virus (DHBV) and treated with AC, three showed negative seroconversion of DHBV DNA and serum DHBV DNA levels significantly decreased after AC administration compared with the controls; DHBV DNA was negative in biopsied liver tissue by in situ hybridization and immunohistochemistry in two ducks treated with AC. Pathological changes were milder in AC-treated ducks than in controls. These results indicate that AC may promote recovery from viral hepatitis and inhibit HBV replication.

Behavior of a PZT ring under non-uniform mechanical stress

Ring-shaped lead zirconate titanate (PZT) piezoelectric vibrators were subjected to non-uniform mechanical stress applied by bolt clamping. The effect of mechanical stress on the effective electromechanical coupling factor (k(eff)) and mechanical quality factor (Qm) of the thickness and wall thickness modes was studied by an equivalent electric circuit analysis. The initiation and propagation of cracks under mechanical stress were also discussed based on the resonance method and the indentation technique. k(eff) for both the thickness and wall thickness modes decreased with increase in mechanical stress due to de-poling of the PZT. Qm of the thickness mode dropped sharply with increase in mechanical stress while Qm of the wall thickness mode remained almost unchange. Existence of microcracks in a PZT vibrator can be detected by the occurrence of spurious vibrations at the wall thickness mode in the electrical impedance vs. frequency spectra.

[Clinical and experimental studies on effects of chronic hepatitis B treated with astragali composita]

Eighty-seven cases of chronic persistent hepatitis (CPH) and 29 cases of chronic active hepatitis (CAH) were treated with Astragali Composita (AC), the clinical markedly effective rates were 69.0% and 55.2%, the total effective rates were 90.8% and 89.7% respectively; the sero-negative conversion rates of HBeAg and HBV-DNA were 27.7% and 28.0% respectively, they were higher than that of control group (P < 0.05-0.01). Eight ducks infected hepatitis B virus were treated with AC, sero-negative conversion of DHBV-DNA was seen in 3 ducks, DHBV-DNA levels of duck sera were lower after treatment than that before treatment (P < 0.05); mild inflammatory changes in liver tissues were seen in 3 ducks, its pathologic changes were milder than that of control groups; DHBV-DNA in liver tissues of 2 ducks was negative in situhybridization. The results indicated that AC had obvious effects of protecting liver tissues and some effects of inhibiting sera HBV and HBV replication.

Capture of gypsy moth,Lymantria dispar (L.), andLymantria mathura (L.) males in traps baited with disparlure enantiomers and olefin precursor in the People's Republic of China

Pheromone traps baited with (+)-disparlure,cis-7,8-epoxy-2methyocta-decane, captured males ofLymantria dispar, L. monacha, andL. mathura in northeastern People's Republic of China.L. dispar responded to the addition of olefin to (+)-disparlure-baited traps in a negative doseresponse manner. Observations on site and seasonal capture ofL. dispar andL. mathura are discussed.

[An epidemiological survey of mumps in Hubei Province]

The results of epidemiological survey of mumps in 1987, Hubei province was reported. 450 primary schools, 60 primary high schools and 60 villages of 15 counties were investigated by using cluster sampling method. 5815 cases of mumps occurred in the population of 281348. The morbidity rate in primary school, primary high school and residents were 37.2%, 7.9% and 4.4%, respectively. The age-peak of mumps was 5-8 years old in school and 6-9 years old in residents. Two epidemic peaks occurred in April and Oct. It was showed that there was a mumps outbreak in large area of Hubei in 1987. The epidemic of mumps broke out firstly in a school and then spread among the residents. Pupils at lower grade had higher risk to this disease. The incidence in primary school of mountainous areas was significantly higher than that of flatlands and urban areas. The serological results of mumps HI test of 563 pupils who were 5-18 years old were also reported. Some proposal for mumps control in China were suggested.