[Effect of sirolimus combined with anti-CD20 monoclonal antibody desensitization on the prognosis of patients underwent haploidentical stem cell transplantation].

Objective: To investigate the effects of sirolimus combined with anti-CD20 monoclonal antibody desensitization on the prognosis of patients with haploidentical stem cell transplantation (haplo-SCT). Methods: Fifteen consecutive patients who received haplo-SCT and pre-transplant donor specific anti-human leukocyte antigen (HLA) antibody (DSA) positive [mean fluorescence intensity (MFI)≥2 000] in the Institute of Hematological Diseases from November 2021 to March 2023 were retrospectively recruited into the desensitized group. There were 4 males and 11 females, with a median age [M(Q1, Q3)] of 48 (37, 59) years. All patients were desensitized with sirolimus combined with anti-CD20 monoclonal antibody. The non-desensitized group included 29 patients with haplo-SCT who had not received desensitization treatment from August 2012 to June 2016. There were 12 males and 17 females with a median age of 42 (26, 50) years. Up to October 1, 2023, the median follow-up time was 13 (9, 18) months in the study group and 23 (14, 29) months in the control group. The changes of MFI before and after desensitization treatment and the prognosis of patients in the desensitized group were compared, including the incidence of primary implantation failure (pGF), neutrophil implantation time, platelet implantation time, grade Ⅱ-Ⅳ acute graft-versus-host disease (GVHD) and chronic GVHD incidence, non-recurrence related mortality, event-free survival rate, disease-free survival rate and overall survival rate. The survival curve was drawn by Kaplan-Meier method, and the survival rate between groups was compared with Log-rank test. Results: After desensitization treatment, the level of DSA MFI in the desensitized group decreased from 8 879 (7 544, 11 495) to 3 781 (1 638, 4 165) after desensitization treatment (P<0.01). All of the patients achieved hematopoietic recovery, and the median time for neutrophil and platelet engraftment were 14 (11, 15) and 20 (18, 25) days, respectively. The incidence of pGF in the desensitized group was 0, which was lower than that in the non-desensitized group (34.5%, 10/29) (P=0.011). The expected 1-year disease-free survival rate and overall survival rate in the desensitized group were 100% (15/15) and 100% (15/15) respectively, while those in the non-desensitized group were 75.9% (22/29) and 75.9% (22/29) respectively, the difference was not statistically significant (both P>0.05). The one-year event-free survival rate in the desensitized group was expected to be 100% (15/15), which was higher than that in the non-desensitized group (51.3%, 15/29) (P=0.002). Conclusion: Sirolimus combined with anti-CD20 monoclonal antibody desensitization therapy can reduce the DSA level of haplo-SCT recipients, promote hematopoietic engraftment after transplantation, and avoid the occurrence of pGF after transplantation.

Effect of fluoro and hydroxy analogies of diglyme on sodium-ion storage in graphite: a computational study.

Diglyme co-intercalation with sodium ion (Na+) into graphite can enable the use of graphite as a potential anode for sodium-ion batteries (NIBs). However, the presence of diglyme molecules in Na+ intercalated graphite limits Na+ storage capacity and increases volume changes. In this work, the effect of functionalising diglyme molecules with fluoro and hydroxy groups on Na+ storage properties in graphite were computationally studied. It was found that the functionalisation can significantly alter the binding between sodium and the solvent ligand as well as between the sodium-solvent complex and the graphite. The hydroxy-functionalised diglyme exhibits the strongest binding to the graphite of the other functionalised diglyme compounds considered. The calculations also reveal that the graphene layer affects the electron distribution on the diglyme molecule and Na, so the diglyme complexed Na binds more strongly to the graphene layer than the Na alone. We also propose a mechanism for the early stages of the intercalation mechanism that involves a reorientation of the sodium-diglyme complex and suggest how the solvent can be designed to optimise the co-intercalation process.

[Clinical characteristics of patients with human adenovirus infection undergoing allogeneic hematopoietic stem cell transplantation].

Objective: To investigate the clinical characteristics and prognosis of human adenovirus (HAdV) infection in patients with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: This is a retrospective case series study. Patients who received allo-HSCT and had symptoms of HAdV infection were tested in the Hematology Department at Perking University People's Hospital from August 2015 to October 2019. Real-time quantitative PCR was used to detect HAdV DNA from 2 728 patients with potential infection. HAdV DNA-positive patients were defined as having HAdV infection. The clinical features of these patients were analyzed, and a case-pair method was used to select patients without HAdV infection as the control group in a 1∶3 ratio. The clinical results of the two groups were compared using Kaplan-Meier and Log-rank testing. Results: A total of 7 119 samples were tested for HAdV, of which 99 samples from 36 patients were positive. Of these patients, 22 developed HAdV viremia, and 24 patients had concurrent infection with another virus. Nineteen patients had fever (53%), 25 had gastrointestinal symptoms (69%), 11 had respiratory symptoms (31%), nine had reduced liver function (25%), and six had nervous system symptoms (17%). Twenty-three patients developed acute graft-versus-host disease of grade 2 or higher. Of all the patients with HAdV infection, nine were treated with cidofovir, seven of whom became HAdV negative and two had invalid treatment. The median follow-up time was 496 (216, 940) d post-HSCT. The overall survival at 5 years post HSCT was 48.4%±9.2% vs. 91.3%±3.5% (χ2=65.03, P<0.001) in patients with and without HADV, respectively. The non-relapse mortality at 5 years post-HSCT was 40.8%±8.8% vs. 4.0%±2.0% (χ2=34.17, P<0.001) in patients with and without HADV, respectively. Conclusions: After allo-HSCT, HAdV-infected patients are dominated by gastrointestinal and respiratory symptoms and have an increased risk of combined acute graft-versus-host disease of >2 degrees. Patients with HAdV infection have poor overall survival and high non-relapse mortality.

Exploring the effect of interlayer distance of expanded graphite for sodium ion storage using first principles calculations.

Expanded graphite (EG) has been shown to be able to store a significant amount of sodium ions. Understanding the alkali metal ion storage in EG is of importance for improving EG electrode performance. In this work, the effect of interlayer distance of pure EG on sodium ion storage was investigated using the density functional theory calculation method. EG structure models with interlayer distances ranging from 3.4 Å to 10.0 Å were simulated. It was found that EG can store a fairly large amount of sodium ions through an intercalation mechanism without any contributions from the co-intercalation mechanism or adsorption mechanism if the interlayer distance is larger than 4.4 Å and smaller than 6.0 Å. It was also found that an interlayer distance of 6.0 Å gives strong binding energy of sodium ions with EG forming thermodynamically stable sodium-graphite intercalation compound (Na-GIC). However, when the interlayer distance becomes larger than 6.0 Å, the binding energy between sodium ions and EG becomes weaker. Computational results have also shown that the enthalpy of formation of the Na-GIC of EG is energetically more favourable when the interlayer distance is increased. An optimal d-spacing of EG for sodium ion storage was identified in this work. These findings provide atomistic insights into sodium ion storage in EG, providing guidelines for the design of graphite-based anode materials for sodium-ion batteries.

[Prognostic significance of DEK-NUP214 fusion gene in patients with acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation].

Objective: To investigate the dynamic change and clinical impact of DEK-NUP214 fusion gene in patients with acute myeloid leukemia (AML) receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: Real-time quantitative polymerase chain reaction (RQ-PCR) and multicolor flow cytometry (FCM) were used to detect DEK-NUP214 gene expression and leukemia-associated immunophenotype (LAIP) in 15 newly diagnosed patients with positive DEK-NUP214 and receiving allo-HSCT from September 2012 to September 2017 at Peking University People's Hospital. The clinical outcome was analyzed using Kaplan-Meier survival curves. The impact of DEK-NUP214 expression was analyzed by log-rank test. Results: The subjects were followed-up with a median period of 657 (62-2 212) days. The median DEK-NUP214 expression level at diagnosis was 488% (274%-1 692%). Thirteen patients achieved complete remission before allo-HSCT. Thirteen patients had a residual DEK-NUP214 expression of 0.38% (0.029%-738.9%) before allo-HSCT. After allo-HSCT, DEK-NUP214 expression in 9/13 patients remained positive, which dropped by around 500 folds (5.7-5 663.0 folds) within a month post-transplant. Five patients died and 2 patients relapsed. The 3-year cumulative incidence of relapse in patients with positive DEK-NUP214 before transplant was 17.5%±11.3% and the 3-year overall survival was 60.5%±13.8%. After allo-HSCT, DEK-NUP214-negative patients had a better outcome. Conclusion: Quantitative monitor of DEK-NUP214 fusion gene could be a sensitive indicator of MRD status after allo-HSCT.

[Negative effects of donor specific anti-HLA antibody on poor hematopoietic recovery in patients with hematological diseases receiving haploidentical stem cell transplantation and rituximab for desensitization].

Objective: To investigate the incidences and risk factors of poor hematopoietic reconstitution (PHR) in patients with hematological diseases who underwent haploidentical allograft and were treated with rituximab for desensitization. Methods: Eight-three donor specific anti-HLA antibody (DSA, 2000 ≤MFI<10 000) positive patients who underwent haploidentical allograft were prospectively enrolled. Rituximab (375 mg/m2) was used for desensitization day-3 of conditioning regimen. Incidence and factors associated with PHR, including primary poor graft function and prolonged thrombocytopenia, were investigated. Results: There were 22 males and 61 females with a median age of 39(range: 1-65) years. Kaplan-Meier analysis showed that the 100 day cumulative incidences of neutrophil and platelet engraftment were 93.0% and 90.7%, respectively. The incidences of PHR were 14.7%. The 3-year relapse rate, non-relapse mortality (NRM) rate, event-free survival (EFS), leukemia-free survival (DFS) and overall survival (OS) were 6.5%, 15.1%, 70.8%, 79.4% and 79.4%, respectively. Patients with DSA MFI<5 000 (group A, n=46) experienced lower PHR (4.4% vs. 27.5%, P=0.003), and higher 3-year EFS (79.5% vs. 59.8%, P=0.020) compared to those with DSA MFI≥5 000 (group B, n=37). Multivariate analysis showed that DSA MFI≥5 000 was correlated with PHR (HR=6.101, P=0.021). PHR was associated with higher NRM (HR=4.110, P=0.026), lower DFS (HR=3.656, P=0.019) and OS (HR=3.656, P=0.019). Conclusion: Our data suggest that high pre-transplant DSA level is a risk factor for PHR in patients with hematological diseases receiving haploidentical allograft and rituximab for desensitization.

The Born model can accurately describe electrostatic ion solvation.

Accurate models of the free energies of ions in solution are crucially important. They can be used to predict and understand the properties of electrolyte solutions in the huge number of important applications where these solutions play a central role such as electrochemical energy storage. The Born model, developed to describe ion solvation free energies, is widely considered to be critically flawed as it predicts a linear response of water to ionic charge, which fails to match water's supposed intrinsic preference to solvate anions over cations. Here, we demonstrate that the asymmetric response observed in simulation is the result of an arbitrary choice of the oxygen atom to be the centre of a water molecule. We show that an alternative and reasonable choice, which places the centre 0.5 Å towards the hydrogen atoms, results in a linear and charge symmetric response of water to ionic charge for a classical water model consistent with the Born model. Therefore, this asymmetry should be regarded as a property of the specific short-range repulsive interaction not an intrinsic electrostatic property of water and so the fact that the Born model does not reproduce it is not a limitation of this approach. We also show that this new water centre results in a more reasonable surface potential contribution to the solvation free energies.

Efficient suppression of the shuttle effect in Na-S batteries with an As2S3 anchoring monolayer.

Sodium-sulfur batteries (NaSBs) have emerged as a promising energy storage technology for large-scale stationary applications such as smart electrical grids due to their exceptionally high energy density and cost-effectiveness. However, one of the challenging problems impeding their practical applications is the sulfur shuttle effect by which the active redox intermediates are gradually dissolved in electrolytes. In this work, we have employed first-principles density functional theory (DFT) calculations to unravel the suppression of the shuttle effect in NaSBs with a two-dimensional (2D) As2S3 monolayer as the anchoring material. We show that semiconducting As2S3 is a suitable anchoring layer to inhibit the dissolution of the polysulfide intermediates in common electrolytes because of its stronger chemical binding with sodium polysulfides than with the electrolytes. The immense adsorption is attributed to the electron donation from the unfilled S-3p states of the polysulfides to As2S3. These mechanisms increase the carrier population and consequently improve the electrical conductivity of As2S3. Hence, the use of As2S3 can both reduce the shuttle effect and enhance the cathode electron conductivity to enable improved cycling stability and coulombic efficiency of the battery.

Quantifying the hydration structure of sodium and potassium ions: taking additional steps on Jacob's Ladder.

The ability to reproduce the experimental structure of water around the sodium and potassium ions is a key test of the quality of interaction potentials due to the central importance of these ions in a wide range of important phenomena. Here, we simulate the Na+ and K+ ions in bulk water using three density functional theory functionals: (1) the generalized gradient approximation (GGA) based dispersion corrected revised Perdew, Burke, and Ernzerhof functional (revPBE-D3) (2) the recently developed strongly constrained and appropriately normed (SCAN) functional (3) the random phase approximation (RPA) functional for potassium. We compare with experimental X-ray diffraction (XRD) and X-ray absorption fine structure (EXAFS) measurements to demonstrate that SCAN accurately reproduces key structural details of the hydration structure around the sodium and potassium cations, whereas revPBE-D3 fails to do so. However, we show that SCAN provides a worse description of pure water in comparison with revPBE-D3. RPA also shows an improvement for K+, but slow convergence prevents rigorous comparison. Finally, we analyse cluster energetics to show SCAN and RPA have smaller fluctuations of the mean error of ion-water cluster binding energies compared with revPBE-D3.

Detecting the undetectable: The role of trace surfactant in the Jones-Ray effect.

The surface tension of dilute salt water is a fundamental property that is crucial to understanding the complexity of many aqueous phase processes. Small ions are known to be repelled from the air-water surface leading to an increase in the surface tension in accordance with the Gibbs adsorption isotherm. The Jones-Ray effect refers to the observation that at extremely low salt concentration, the surface tension decreases. Determining the mechanism that is responsible for this Jones-Ray effect is important for theoretically predicting the distribution of ions near surfaces. Here we use both experimental surface tension measurements and numerical solution of the Poisson-Boltzmann equation to demonstrate that very low concentrations of surfactant in water create a Jones-Ray effect. We also demonstrate that the low concentrations of the surfactant necessary to create the Jones-Ray effect are too small to be detectable by surface sensitive spectroscopic measurements. The effect of surface curvature on this behavior is also examined, and the implications for unexplained bubble phenomena are discussed. This work suggests that the purity standards for water may be inadequate and that the interactions between ions with background impurities are important to incorporate into our understanding of the driving forces that give rise to the speciation of ions at interfaces.

[Risk stratification of type-specific human papillomavirus for cervical precancers: evidence from a cross-sectional study in Shenzhen].

Objective: To analyze the epidemiological genotype features of human papillomavirus (HPV) in cervical infection and their risks for cervical precancers among women in Shenzhen area. Methods: A total of 2 717 individuals ranging in age from 30~59 years were recruited in 18 community health centers of Shenzhen city from March 1 to June 15, 2015 by a cluster sampling method. The results of genotype of HPV, liquid-based cytology (LBC), colposcopy and pathology were analyzed. The clinical sensitivity and specificity as well as positive (PPV) and negative (NPV) predictive values of the combination of different HPV genotype in screening the cervical intraepithelial neoplasia (CIN) 2 and above were estimated. Results: The HPV infection rate in Shenzhen area was 15.9% (432/2 717). The most common HPV genotype was HPV52 (22.9%), followed by HPV16 (12.7%), HPV53 (10.0%), HPV51 (8.6%) and HPV58 (8.1%). Compared with HPV16/18 genotyping, HPV33/16 genotyping had a higher sensitivity (57.1% vs. 42.9%, P<0.05) and an analogous specificity (87.3% vs. 86.9%, P>0.05) in predicting CIN2+ . The sensitivity of combination of HPV33/16 genotyping and low grade squamous intraepithelial lesion (LSIL) positive tested by LBC in predicting CIN2+ was 75.0%, significantly higher than 64.3% of atypical squamous cells of undetermined significance (ASC-US) positive tested by LBC alone (P<0.05). The specificities of these two methods mentioned above in predicting CIN2+ were 83.5% and 89.2%, respectively, without statistical difference (P>0.05). Conclusions: Women infected by HPV have distinct risks for CIN2+ according to different high-risk HPV genotypes. The top five risks were HPV 33, 16, 58, 56, and 68. HPV-positive women triaged by LBC LSIL+ combined with HPV33/16 genotyping may be a potential strategy for cervical cancer screening in developed urban area.

[An analysis of the characteristics of perioperative cardiac troponin elevation in orthopaedic surgical patients].

Objective: Perioperative myocardial infarction remains a severe complication in non-cardiac surgery and is one of the major causes of death. Cardiac troponin (cTn) I elevation is associated with short-term and long-term mortality. The aim of the study was to assess the proportion rate of cTnI elevation and its clinical characteristics among patients admitted for orthopaedic surgery with or without cardiovascular events. Methods: This is a retrospective study including 27 744 patients aged 50 years or older who admitted for orthopaedic surgery from 2009-2015 in Beijing Jishuitan Hospital. Results: Two hundred and sixty-five patients [age (71.7±9.9) years] had cTnI level> 0.04 µg/L with 66% (175 patients) of them being female. Among them, 59 patients were isolated troponin rise (ITR) (n=59), 13 were preoperative acute myocardial infarction (AMI), and 193 were postoperative AMI. The proportion of postoperative AMI was 0.69%. Those patients were more likely to have a history of coronary artery disease or hypertension. Non-ST-segment elevation myocardial infarction (NSTEMI) was more common (93.3%) than ST-segment elevation myocardial infarction in these patients. Most of them did not experience ischemic symptoms. Totally 76.7% of the AMI occurred within 3 days of surgery; and the in-hospital mortality rate was 10.4%. Conclusions: Perioperative elevation of troponin is common in patients undergoing orthopaedic surgery. Most postoperative AMI were NSTEMI and with absent or atypical ischemia symptoms. Monitoring troponin levels and electrocardiograph in at-risk patients is needed to find most of the AMI.

[Distribution and associated factors of high-risk HPV genotypes infection among HPV-positive women who participated cervical screening test in Shenzhen, 2014-2016, China].

Objective: To analyze the distribution and associated factors of high-risk genotypes of HPV in cervical infection among women in Shenzhen. Methods: The information on sociodemographic characteristics and HPV genotypes of HPV-positive women who participated cervical screening test from January 2014 to December 2016 was downloaded from Shenzhen Maternity and Child Healthcare Management Information System. According to the pathogenicity, the high-risk HPV genotypes were divided into 15 types including HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68; and there were 6 low-risk genotypes including HPV 6, 11, 42, 43, 44, and 81. Chi-square tests were applied to compare the proportions of high-risk HPV infection among women who had different sociodemographic characteristics. A non-conditional logistic regression model was used to analyze the associated factors for high-risk HPV infection. Results: In total, all HIV positives received HPV genotyping, with an average age of (38.08±9.38) years old. There were 9 979 (93.9%) high-risk and 645 (6.1%) low-risk HPV infections. The proportions of HPV infections for high-risk type in each year were 91.5%, 93.8%, and 95.6%, increasing with the screening years (χ(2)=54.79, P<0.001). Multivariate logistic regression analysis showed that compared with women younger than 25 years old, women in other age groups (at age 26 to 30 years, 31 to 35 years, 36 to 40 years, 41 to 45 years, and 50 years or older) had increased risks of high-risk HPV infection, with OR (95%CI) of 1.67 (1.20-2.31), 1.49 (1.09-2.03), 1.71 (1.23-2.37), 1.65 (1.19-2.31), and 1.84 (1.26-2.67), respectively; compared with the married, single women had a decreased risk of high-risk HPV infection (OR (95%CI): 0.71 (0.50-1.00)); women received HPV testing in 2015 and 2016 showed higher risk of high-risk HPV infection than those in 2014 (OR (95%CI): 1.43 (1.17-1.74) and 2.03 (1.68-2.46)). The 5 most common HPV genotypes were HPV52 (25.1%, 2 670 cases), followed by HPV16 (19.2%, 2 041 cases), HPV58 (13.3%, 1 413 cases), HPV18 (9.9%, 1 048 cases), and HPV51 (9.3%, 993 cases). Conclusion: Age, marital status, and screening year were associated with high-risk HPV infections. Besides HPV16 and HPV18, the prevention and control on HPV infections for HPV52, HPV58, and HPV51 should be prioritized in Shenzhen area.

[Clinical features and early treatment effects in intermediate risk and poor risk acute myeloid leukemia with EVI1 positive].

OBJECTIVE: To investigate the clinical biological characteristics of EVI1 positive acute myeloid leukemia (AML) and its effect on early chemotherapy. METHODS: The clinical and biological cha-racteristics of 33 AML patients with EVI1 positive were retrospectively analyzed in 361 AML patients who were diagnosed and treated in our institute from March 2015 to July 2016, and the clinical and biological features, and rates of the induced remission were compared between the intermediate risk and poor risk with EVI1 positive AML, moreover, the influential factors on complete remission (CR) were analyzed. The expression of EVI1/ABL was tested in 32 healthy donors to confirm the abnormal threshold of EVI1 expression. RESULTS: The definition of EVI1 positive was that the quantitative expression of EVI1/ABL was more than 8.0%. The 33 AML patients with EVI1 positive were found in 361 newly diagnosed AML patients, in which the female and male patients were 17 and 16 respectively, the median age was 45 (18-67) years, with a median follow-up of 6.6 (0.7-13.2) months. Intermediate karyotype was found in 17 patients(including 9 patients with normal karyotypes,1 patient with +8);unfavorable karyotype was found in 14 patients [including 7 patients with -7/7q-,4 patients with t (v;11q23),3 patients with inv(3)/t(3;3), and 2 patients without mitotic figures]. The rate of CR in the first induction chemotherapy was 42.4%, and the rate of total CR was 60.6%. According to the NCCN, 16 intermediate risk patients and poor risk patients were divided, without favorable risk patients. The rate of CR in the first induction chemotherapy were 68.8% and 17.6% (P=0.005) in the intermediate risk and poor risk respectively, that of total CR were 81.3% and 41.2%(P=0.032), and the rates of relapse were 7.7% and 14.3%.Univariable analysis revealed that unfavorable karyotype could affect the rate of CR in the first reduction chemotherapy and that of total CR (P=0.004, 0.029). The poor risk patients had higher mortality (41.2% vs. 6.3%, P=0.039) and lower overall survival (OS)(P=0.012). CONCLUSION: EVI1 may be not an independent prognostic factor for the AML patients considering the appea-rance in the intermediate and poor risk patients. It predicts poor outcome in the EVI1 positive AML patients who have unfavorable karyocytes, such as -7/7q-, t(v;11q23), and inv(3)/t(3;3), and also a low rate of both CR in the first induction chemotherapy and total CR. It also has a low rate of long-term survival and high mortality in the AML patients with EVI1 positive, who may benefit from allogeneic bone marrow transplantation as soon as possible.

[Analysis of the impact of job characteristics and organizational support for workplace violence].

Objective: To analyze the effect of job characteristics and organizational support for workplace violence, explore the influence path and the theoretical model, and provide a theoretical basis for reducing workplace violence. Methods: Stratified random sampling was used to select 813 medical staff, conductors and bus drivers in Chongqing with a self-made questionnaire to investigate job characteristics, organization attitude toward workplace violence, workplace violence, fear of violence, workplace violence, etc from February to October, 2014. Amos 21.0 was used to analyze the path and to establish a theoretical model of workplace violence. Results: The odds ratio of work characteristics and organizational attitude to workplace violence were 6.033 and 0.669, respectively, and the path coefficients were 0.41 and-0.14, respectively (P<0.05). The Fitting indexes of the model: Chi-square (χ(2)) =67.835, The ratio of the chi-square to the degree of freedom (χ(2)/df) =5.112, Good-of-fit index (GFI) =0.970, Adjusted good-of-fit index (AGFI) =0.945, Normed fit index (NFI) =0.923, Root mean square error of approximation (RMSEA) =0.071, Fit criterion (Fmin) =0.092, so the model fit well with the data. Conclusion: The job characteristic is a risk factor for workplace violence while organizational attitude is a protective factor for workplace violence, so changing the job characteristics and improving the enthusiasm of the organization to deal with workplace violence are conducive to reduce workplace violence and increase loyalty to the unit.

Establishment of plasma microRNA detection method by using taqman probe based quantitative reverse transcription PCR.

MicroRNAs (miRNAs) are a kind of short non—coding RNAs that regulate gene expression at the post—transcriptional level. Recently, many studies have found that circulating miRNAs have the potential to sever as diagnostic biomarkers for many diseases. However, the methods for the quantification of circulating miRNAs still need more adjustment. In this study, we tried to establish a reliable method to quantify the plasma miRNAs. We used quantitative real—time PCR with taqman probes to detect the plasma miR—153 level. Three controls were used in this study, including two external miRNAs control from C. elegans miRNAs (cel—miR—54 and cel—miR—238) and one internal control (hsa—miR—486). All of these controls were stable in plasma and the cel—miR—238/cel—miR—54/hsa—miR—486 combination could improve the normalization process. The expression level of the target miRNA, human plasma miR—153, could be quantified accurately with taqman probes .The assay has high accuracy, high sensitivity and a large dynamic range from 100 copies to 10(13) copies in the PCR reaction. Our study provided a standardized quantification method for plasma miRNAs which might be used as biomarker in many diseases research.

Formic acid-assisted synthesis of palladium nanocrystals and their electrocatalytic properties.

Palladium (Pd) nanocrystals have been synthesized by using formic acid as the reducing agent at room temperature. When the concentration of formic acid was increased continuously, the size of Pd nanocrystals first decreased to a minimum and then increased slightly again. The products have been investigated by a series of techniques, including X-ray diffraction, high-resolution transmission electron microscopy (HRTEM), UV-vis absorption, and electrochemical measurements. The formation of Pd nanocrystals is proposed to be closely related to the dynamical imbalance of the growth and dissolution rate of Pd nanocrystals associated with the adsorption of formate ions onto the surface of the intermediates. It is found that small Pd nanocrystals showed blue-shifted adsorption peaks compared with large ones. Pd nanocrystals with the smallest size display the highest electrocatalytic activity for the electrooxidation of formic acid and ethanol on the basis of cyclic voltammetry and chronoamperometric data. It is suggested that both the electrochemical active surface area and the small size effect are the key roles in determining the electrocatalytic performances of Pd nanocrystals. A "dissolution-deposition-aggregation" process is proposed to explain the variation of the electrocatalytic activity during the electrocatalysis according to the HRTEM characterization.