Effect of Free Cells and Additional Supporting Material on Performance of Polyethylene Glycol (PEG)-Pellet Reactor to Treat NH4-N Contaminated Groundwater

To study the effect of free cells (suspended bacteria) on performance of entrapped bacteria system (i.e. polyethylene glycol (PEG)-pellet reactor) to treat NH4-N contaminated groundwater, two PEG-pellet reactors with a lot of free cells - Reactor A containing PEG-pellet and Reactor B containing PEG-pellet and supporting material - and the another control reactor without free cells (Reactor C) were set-up. Three reactors were operated under various NH4-N concentrations (40-60 mg/L) and various temperatures (5-25oC). The results show that the free cells effected on the NH4-N removal efficiency significantly. The free cells developed to be a biofilm layer on the pellet surface for Reactor A, the biofilm layer caused the decreasing NH4-N diffusion and incomplete nitrification eventually. On the other hand, most free cells attached to the supporting material for Reactor B. Although the NH4-N could diffuse properly, the free cells consuming acetate caused the added acetate was insufficient for complete denitrification. However, the results suggest that the supporting material could reduce the effect of free cells on the reactor performance at low temperature as indicated by 1) higher efficiency and 2) lower activation energy (Ea) for nitrification and denitrification in Reactor B than Reactor A.

回传容量受限的Cell-free大规模MIMO传输研究综述

去蜂窝(Cell-free)大规模多输入多输出(Multiple Input Multiple Output,MIMO)是第六代移动通信(6G)的关键技术之一。在Cell-free大规模MIMO中,接入节点(Access Point,AP)将接收到的信号通过回传链路传输至中央处理器(Central Processing Unit,CPU)完成信道估计、数据检测等操作,有效地缓解了AP计算压力。随着网络中用户数的增多,回传链路将面临极大的挑战。从回传容量受限的角度出发,分析了回传容量受限的Cell-free大规模MIMO上行传输发展现状,并对其发展趋势进行了探讨。

Revolutionizing Non-Invasive Biomarker Discoveries: The Power of Methylation Screening Analysis in Cell-Free DNA Liquid Biopsy

Epigenetic changes of DNA, including methylation, have long been recognized as key indicators of various diseases, including aging, cancer, and neurological disorders. Biomarker discoveries based on distinct methylation patterns for both hypermethylation and hypomethylation lead the way in discovery of novel diagnosis and treatment targets. Many different approaches are present to detect the level of methylation in whole genome (whole genome bisulfite sequencing, microarray) as well as at specific loci (methylation specific PCR). Cell-free DNA (cf-DNA) found in body fluids like blood provides information about DNA methylation and serves as a less invasive approach for genetic screening. Cell-free DNA and methylation screening technologies, when combined, have the potential to transform the way we approach genetic screening and personalized therapy. These technologies can help enhance disease diagnostic accuracy and inform the development of targeted therapeutics by providing a non-invasive way for acquiring genomic information and identifying disease-associated methylation patterns. We highlight the clinical benefits of using cell-free DNA (cf-DNA) liquid biopsy analysis and available methylation screening technologies that have been crucial in identifying biomarkers for disease from patients using a non-invasive way. Powering such biomarker discoveries are various methods of cf-DNA methylation analysis such as Bisulfite Sequencing and most recently, Methylation-Specific Restriction Enzyme (MSRE-seq) Analysis, paving the way for novel epigenetic biomarker discoveries for more robust diagnosis such as early disease detection, prognosis, monitoring of disease progression and treatment response as well as discovery of novel drug targets.

Effects of processing pH stimulation on cooperative bioleaching of chalcopyrite concentrate by free and attached cells

In order to investigate the effects of processing pH stimulation on bioleaching of chalcopyrite by moderate thermophiles,copper leaching rates and the dynamics of microbial community structures of free and attached cells were monitored. The results indicated that when the processing pH values were respectively adjusted to 1.0 and 3.0 on day 14, both free and attached cells experienced an adaptive phase. Meanwhile, the copper leaching rates were 86.9% and 64.0%,respectively, as opposed to a copper leaching rate of 87.5% in the control group without pH stimulation. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis suggested that pH stimulation imposed less impact on the attached organisms than on the free cells, indicating that the attached cells were more resistant to processing pH stimulation than the free cells. Furthermore, adjusting processing pH to 3.0 significantly disrupted both free and attached microbial communities, and the bioleaching system could not recover to the normal status as the control group.

Cell-Free大规模MIMO系统中基于传输时延的缓存策略研究

为了满足未来移动互联网中用户的超低时延和超高可靠需求,将无线缓存技术与无小区大规模多输入多输出系统相结合,设计了基于AP间协作缓存及区域流行度评估的缓存模型。推导出涉及AP分簇、协作缓存以及区域流行度的传输时延表达式,并将内容放置问题表述为最小化总内容传输时延问题。通过对优化问题的NP-hard和拟阵约束下次模单调性的证明,提出了基于贪婪算法的缓存部署优化策略。仿真结果表明,所提策略可有效降低系统内容传输时延和提升缓存命中率。

Diagnostic value of negative enrichment and immune fluorescence in situ hybridization for intraperitoneal free cancer cells of gastric cancer

Objective:To explore the intraperitoneal free cancer cell(IFCC)detection value of negative enrichment and immune fluorescence in situ hybridization(NEimFISH)on chromosomes(CEN)8/17.Methods:To verify the reliability of NEimFISH,29 gastric cancer tumors,their adjacent tissues and greater omental tissues were tested.Our study then included 105 gastric cancer patients for IFCC.We defined patients as IFCC-positive if a signal was detected,regardless of the detailed cancer cell numbers.A comparison of clinicopathological features was conducted among IFCC groups.We also compared the diagnosis value and peritoneal recurrence predictive value among different detection methods.The comparison of IFCC number was also conducted among different groups.Results:A cutoff of 2.5 positive cells could distinguish all benign tissue samples and 97%of malignant tissue samples in our study.Compared to intestinal gastric cancer,patients with diffuse gastric cancer tended to have more IFCCs(6 vs.4,P=0.002).The IFCC counts were often higher in the lymphovascular invasion positive group than negative group(3 vs.1,P=0.022).All IFCC samples that were considered positive using conventional cytology were also found to be positive using NEimFISH.When compared to conventional cytology and paraffin pathology,NEimFISH had a higher IFCC positive rate(68.9%)and higher one-year peritoneal recurrence predictive value with area under the curve(AUC)of 0.922.Conclusions:Gastric cancer could be effectively diagnosed by NEimFISH.The IFCC number found using NEimFISH on CEN8/17 is closely associated with Lauren type and vascular invasion of cancer.NEimFISH is a reliable detection modality with a higher positive detection rate,higher one-year peritoneal recurrence predictive value and quantitative features for IFCC of gastric cancer.

Deactivation Kinetics of Nitrile Hydratase in Free Resting Cells

Nitrile hydratase (NHase) is an important industrial enzyme used for acrylamide production from acrylonitrile.The deactivation kinetics of NHases in free resting cells of Rhodococcus sp.was presented based on a bi-steady state assumption.Effects of hydration temperature,product concentration and substrate concentration on NHase deactivation were investigated experimentally and correlated with a first order deactivation kinetics.The results showed that the hydration temperature and product concentration were major factors governing the deactivation of NHases under substrate-feeding conditions.When acrylamide concentration was higher than 250 g·L1,the deactivation of NHases became serious and the bi-steady state assumption was not applicable.When the hydration temperature was controlled at a relatively higher level such as 28°C,the total deactivation rate constant was about 2.8-fold of that at 20°C.

Establishment of Cell Free Conversion System With Biotin-labelled Recombinant PrP^(sen) Expressed in E.coli

Objective To report a protocol using biotin-labelled PrP protein in cell free conversion assay instead of isotope. Methods A hamster PrP protein （HaPrP） was expressed in E. coli and purified with HIS-tag affinity chromatograph. After being labelled with biotin, HaPrP was mixed with PrP^sen preparation from scrapie strain 263K. Results Protease-resistant bands were detected after four-day incubation. Conclusion The new conversion model provides a reliable, easily handling, and environment-friendly method for studies of prion and transmissible spongiform encephalopathies.

Role of free fatty acids in proliferation of rat hepatic stellate cells(Ⅱ)

AIM To study the role of free fatty acids (arachidonic acid and linoleic acid) in proliferation of rat hepatic stellate cells (HSC). METHODS HSC were isolated and cultured from liver of Wistar rats by in situ perfusion with pronase and collagenase, and density gradient centrifugation with Nycodenz. MTT colorimetric assay was detected for HSC proliferation. RESULTS Arachidonic acid and linoleic acid had an effect on proliferation of HSC. Arachidonic acid of 25mg/L promoted HSC proliferation ( P <0 01), but 50 and 100mg/L had an inhibitory effect on HSC ( P <0 01), and showed cytotoxity on HSC under inverted microscope; 6 25, 12 5 and 25mg/L of linoleic acid had no effect on HSC proliferation ( P >0 05), but with concentration increasing, 50 and 100mg/L of linoleic acid might promote HSC proliferation ( P <0 05 or 0 01). CONCLUSION Arachidonic acid and linoleic acid may promote HSC proliferation, but increased concentration can have cytotoxity on HSC. Arachidonic acid and linoleic acid might be associated with fatty liver and hepatic fibrogenesis by lipid peroxidation.

Detection methods and clinical significance of free peritoneal tumor cells found during colorectal cancer surgery

Peritoneal washing is now part of the standard clinical practice in several abdominal and pelvic neoplasias. However, in colorectal cancer surgery, intra-peritoneal free cancer cells(IFCC) presence is not routinely investigated and their prognostic meaning is still unclear. When peritoneal washing results are positive for the presence of IFCC a worse outcome is usually expected in these colorectal cancer operated patients, but it what is not clear is whether it is associated with an increased risk of local recurrence. It is authors' belief that one of the main reasons why IFCC are not researched as integral part of the routine staging system for colon cancer is that there still isn't a diagnostic or detection method with enough sensibility and specificity. However, the potential clinical implications of a routine research for the presence IFCC in colon neoplasias are enormous: not only to obtain a more accurate clinical staging but also to offer different therapy protocols, based on the presence of IFCC. Based on this, adjuvant chemotherapy could be offered to those patients found to be positive for IFCC; also, protocols of proactive intraperitoneal chemotherapy could be applied. Although presence of IFCC appears to have a valid prognostic significance, further studies are needed to standardize detection and examination procedures, to determine if there are and which are the stages more likely to benefit from routine search for IFCC.

Value of circulating cell-free DNA in diagnosis of hepatocelluar carcinoma

AIM:To investigate the value of combined detection of circulating cell-free DNA(cfDNA),a-fetal protein(AFP) and a L-fucosidase(AFU) for diagnosis of hepatocellular carcinoma(HCC).METHODS:Serum samples from 39 HCC patients and 45 normal controls were collected.Branched DNA(bDNA) was used to detect the level of cfDNA,and a receiver operating characteristic curve was employed to evaluate the diagnostic sensitivity,specificity,accuracy,positive predictive value,negative predictive value,positive likelihood ratio,negative likelihood ratio and Youden index,and to assess the diagnostic efficiency and their correlations with the clinicopathological features.AFP and AFU were detected by chemiluminescence and colorimetry,respectively.The significance of combined detection of the three biomarkers was discussed.RESULTS:cfDNA level was increased in 22 of the 39 HCC samples and in 2 of the 45 normal controls.cfDNA level in HCC samples was significantly higher than that in normal controls(P < 0.05).There were significant differences in sex and extra-and intrahepatic metastasis(P < 0.05).There was no significant correlation between cfDNA,AFP and AFU in the detection of HCC.The sensitivity of combined detection of cfDNA with one marker(AFP or AFU) and cfDNA with two markers(AFP and AFU) was 71.8%,87.2% and 89.7% vs 56.4%,53.8% and 66.7% for cfDNA,AFP and AFU used alone,respectively,the difference being statistically significant(P < 0.05).CONCLUSION:Quantitative analysis of cfDNA is sensitive and feasible,and the combined detection of cfDNA with AFP or AFU or both could improve the diagnostic sensitivity for HCC.

Detection of fusion gene in cell-free DNA of a gastric synovial sarcoma

Synovial sarcoma(SS) is genetically characterized by chromosomal translocation, which generates SYT-SSX fusion transcripts. Although SS can occur in any body part, primary gastric SS is substantially rare. Here we describe a detection of the fusion gene sequence of gastric SS in plasma cell-free DNA(cf DNA). A gastric submucosal tumor was detected in the stomach of a 27-year-old woman and diagnosed as SS. Candidate intronic primers were designed to detect the intronic fusion breakpoint and this fusion sequence was confirmed in intron 10 of SYT and intron 5 of SSX2 by genomic polymerase chain reaction(PCR) and direct sequencing. A locked nucleic acid(LNA) probe specificto the fusion sequence was designed for detecting the fusion sequence in plasma and the fusion sequence was detected in preoperative plasma cfD NA, while not detected in postoperative plasma cfD NA. This technique will be useful for monitoring translocation-derived diseases such as SS.

Liquid biopsy in patients with pancreatic cancer: Circulating tumor cells and cell-free nucleic acids

Despite recent advances in surgical techniques and perioperative management, the prognosis of pancreatic cancer(PCa) remains extremely poor. To provide optimal treatment for each patient with Pca, superior biomarkers are urgently needed in all phases of management from early detection to staging, treatment monitoring, and prognosis. In the blood of patients with cancer, circulating tumor cells(CTCs) and cell-free nucleic acids(cf NAs), such as DNA, m RNA, and noncoding RNA have been recognized. In the recent years, their presence in the blood has encouraged researchers to investigate their potential use as novel blood biomarkers, and numerous studies have demonstrated their potential clinical utility as a biomarker for certain types of cancer. This concept, called "liquid biopsy" has been focused on as a less invasive, alternative approach to cancer tissue biopsy for obtaining genetic and epigenetic aberrations that contribute to oncogenesis and cancer progression. In this article, we review the available literature on CTCs and cfN As in patients with cancer, particularly focusing on PCa, and discuss future perspectives in this field.

Quick recovery and characterization of cell-free DNA in seminal plasma of normozoospermia and azoospermia： implications for non-invasive genetic utilities

We established a quick and reliable method for recovering cell-free seminal DNA （cfsDNA）, by using the binding-washing-elution procedure on the DNA purification column. Low variations （below 15%） among the triplicate values of cfsDNA quantity verified the reproducibility of our cfsDNA recovery method. Similar cfsDNA yield and size distribution between seminal plasma acquired by filtration and centrifugation confirmed the presence of cfsDNA. To investigate the general characterization of cfsDNA, the quantitation and size distribution of cfsDNA from normozoospermic and azoospermic semen were analyzed by real-time PCR and electrophoresis, respectively. CfsDNA concentration in semen with normozoospermia （n = 11） was 1.34 ± 0.65 μg ·mL^-1, whereas a higher cfsDNA concentration was observed in azoospermia （2.56 ± 1.43 μg ·mL^-1, n = 9）. The continuous distribution of DNA fragments ranging from -1 kb to 15 kb and a spectrum of multiples of 180-bp fragments were observed in each normozoospermic and azoospermic sample. Distinct characteristic DNA ladder fragmentations in some azoospermic samples implicated that cfsDNA originate partly from apoptotic cells. CfsDNAs of 36 selected azoospermic patients with known information of Y chromosome microdeletion were subjected to the same microdeletion analysis by multiplex PCR and PCR amplification of sY114 （1 450 bp）. All multiplex PCR reactions with cfsDNA amplified successfully and provided the same result as leukocyte DNA. PCR amplification of sY114 gave a 1 450-bp amplicon as expected. Our data suggested the potential use of cfsDNA in search of biomarker or diagnostic procedures.

Value of dynamic plasma cell-free DNA monitoring in septic shock syndrome: A case report

BACKGROUND Mortality due to septic shock is relatively high.The dynamic monitoring of plasma cell-free DNA(cfDNA)can guide the treatment of septic shock.CASE SUMMARY Herein,we present a typical case of septic shock syndrome caused by the bacilli Acinetobacter baumannii and Pantoea.The patient complained of abdominal pain,fever and chills upon admission to the Emergency Department.Marked decreases in white blood cells and procalcitonin(PCT)were observed after the patient received continuous renal replacement and extracorporeal membrane oxygenation.Plasma cfDNA levels were consistently high,peaking at 1366.40 ng/mL,as measured by a duplex real-time PCR assay with an internal control,which was developed as a novel method for the accurate quantification of cfDNA.The patient died of septic shock on HD 8,suggesting that cfDNA could be used to monitor disease progression more effectively than PCT and the other inflammatory factors measured in this case.CONCLUSION CfDNA may be a promising marker that complements other inflammatory factors to monitor disease progression in patients with septic shock.

Cell membrane and bioactive factors derived from mesenchymal stromal cells: Cell-free based therapy for inflammatory bowel diseases

Inflammatory bowel diseases(IBD)are chronic inflammatory disorders of the gastrointestinal tract associated with multifactorial conditions such as ulcerative colitis and Crohn’s disease.Although the underlying mechanisms of IBD remain unclear,growing evidence has shown that dysregulated immune system reactions in genetically susceptible individuals contribute to mucosal inflammation.However,conventional treatments have been effective in inducing remission of IBD but not in preventing the relapse of them.In this way,mesenchymal stromal cells(MSC)therapy has been recognized as a promising treatment for IBD due to their immunomodulatory properties,ability to differentiate into several tissues,and homing to inflammatory sites.Even so,literature is conflicted regarding the location and persistence of MSC in the body after transplantation.For this reason,recent studies have focused on the paracrine effect of the biofactors secreted by MSC,especially in relation to the immunomodulatory potential of soluble factors(cytokines,chemokines,and growth factors)and extracellular vehicles that are involved in cell communication and in the transfer of cellular material,such as proteins,lipids,and nucleic acids.Moreover,treatment with interferon-γ,tumor necrosis factor-α,and interleukin-1βcauses MSC to express immunomodulatory molecules that mediate the suppression via cell-contact dependent mechanisms.Taken together,we present an overview of the role of bioactive factors and cell membrane proteins derived from MSC as a cell-free therapy that can improve IBD treatment.

Research progress in lead-less or lead-free three-dimensional perovskite absorber materials for solar cells

The trend toward lead-free or lead-less perovskite solar cells(PSCs) has attracted increasing attention over the past few years because the toxicity of lead(Pb) is one of the substantial restrictions for large-scale applications. Researchers have investigated the viability of substituting Pb with other elements(group 14 elements, group 2 elements, transition-metal elements, and group 13 and 15 elements) in the three-dimensional(3 D) perovskites by theoretical calculations and experimental explorations. In this paper, recent research progress in Pb-less and Pb-free PSCs on the perovskite compositions, deposition methods, and device structures are summarized and the main problems that hinder the enhancement of device efficiency and stability are discussed in detail. To date, the fully Sn-based PSCs have shown a power conversion efficiency(PCE) of 8.12% and poor device stability. However, lead-less PSCs have shown higher PCE and a better stability. In addition, the introduction of double-perovskite materials also draws researchers' attention. We believe that the engineering of elemental composition, perovskite deposition methods, and interfacial modification are critical for the future development of Pb-less and Pb-free PSCs.

Comparison of peritoneal free gastric cancer cells' detecting rates between laparoscopically assisted and open radical gastrectomy

Objective： To compare laparoscopic gastrectomy and conventional surgery on the dissemination and seeding of tumor cells. Methods：Intraoperative peritoneal lavage cytologic examination was performed in 65 patients with gastric cancer, during laparoscopic gastrectomy （n = 34） and conventional surgery （n = 31）. Cytology was examined twice, immediately after opening the peritoneal cavity and just before closing the abdomen. Saline was poured into the peritoneal cavity, and 100 ml fluid was retrieved after irrigation. Laparoscopic instruments were lavaged after surgery with 100 ml saline. Carbon dioxide （COz） was derived through the trocar side orifice after pneumoperitoneum during laparoscopic gastrectomy and filtered through 100 ml saline. Cytologic examination of the filtrate was performed after the filtration process. Results： The incidence of positive cytology during laparoscopic surgery was 32.26% in the preoperative lavage and 22.58% in the postoperative lavage. The incidence of positive cytology during conventional surgery was 41.18% before lavage and 26.47% after lavage. Only one positive cytology was detected in the CO2 filtrate gas. The incidence of positive cytology in the lavage of the instruments during laparoscopic surgery was 6.45 %. Conclusion： During gastric laparoscopic surgery, CO2 pneumoperitoneum does not affect tumor cell dissemination and seeding. In this study, laparoscopic techniques used in gastric cancer surgery were not associated with a higher risk for intraperitoneal dissemination of cancer cells than the conventional surgery.

THE RELATIONSHIP BETWEEN SEROSAL TYPES, PATHOLOGICAL CHARACTERISTICS AND FREE CANCER CELLS IN THE PERITONEAL CAVITY OF GASTRIC CANCER PATIENTS

The relationship between free cancer cells and the pathological characteristics of gastric cancer were studied. Of 100 cases of gastric cancer, free cancer cells in the peritoneal cavity were detected in 32 cases (32%). Free cancer cells were most often found in tendonoid (62.2%) and colour diffused (60.0%) serosal types. When the area of serosal invasion was over 20 cm, the positive free cancer cell rate was 56.6% and only 2.5% if below 20 cm. Free cancer cells were related to the depth of cancer infiltration, often found in the S2 and S3 invasion layers, as well as to the pathological characteristics of gastric cancer. Free cancer cells were often seen in infiltrated type cancer, histologically poorly differentiated or undifferentiated adenocarcinoma. and nest or diffused growth types. In patients without peritoneal metastasis (P0), the positive rate was 26.1%. This study proved that Chen's serosal classification is correct and useful in assessing whether the cancer cells have penetrated through the serosa or not during surgery. Different treatments should be used in the cases with different serosal types. In addition to surgery, destruction of free cancer cells should be considered in tendonoid and colour diffused serosal types, so as to prevent peritoneal metastasis.

Effects of leukemia inhibitory factor and basic fibroblast growth factor on free radicals and endogenous stem cell proliferation in a mouse model of cerebral infarction

The present study established a mouse model of cerebral infarction by middle cerebral artery occlusion, and monitored the effect of 25 tJg/kg leukemia inhibitory factor and （or） basic fibroblast growth factor administration 2 hours after model establishment. Results showed that following administration, the number of endogenous neural stem cells in the infarct area significantly increased, malondialdehyde content in brain tissue homogenates significantly decreased, nitric oxide content, glutathione peroxidase and superoxide dismutase activity significantly elevated, and mouse motor function significantly improved as confirmed by the rotarod and bar grab tests. In particular, the effect of leukemia inhibitory factor in combination with basic fibroblast growth factor was the most significant. Results indicate that leukemia inhibitory factor and basic fibroblast growth factor can improve the microenvironment after cerebral infarction by altering free radical levels, improving the quantity of endogenous neural stem cells, and promoting neurological function of mice with cerebral infarction.