Defect Emission and Its Dipole Orientation in Layered Ternary Znln2 S4 Semiconductor.

Defect engineering is promising to tailor the physical properties of 2D semiconductors for function-oriented electronics and optoelectronics. Compared with the extensively studied 2D binary materials, the origin of defects and their influence on physical properties of 2D ternary semiconductors are not clarified. Here, the effect of defects on the electronic structure and optical properties of few-layer hexagonal Znln2 S4 is thoroughly studied via versatile spectroscopic tools in combination with theoretical calculations. It is demonstrated that the Zn-In antistructural defects induce the formation of a series of donor and acceptor energy levels and sulfur vacancies induce donor energy levels, leading to rich recombination paths for defect emission and extrinsic absorption. Impressively, the emission of donor-acceptor pair in Znln2 S4 can be significantly tailored by electrostatic gating due to efficient tunability of Fermi level (Ef ). Furthermore, the layer-dependent dipole orientation of defect emission in Znln2 S4 is directly revealed by back focal plane imagining, where it presents obviously in-plane dipole orientation within a dozen-layer thickness of Znln2 S4 . These unique features of defects in Znln2 S4 including extrinsic absorption, rich recombination paths, gate tunability, and in-plane dipole orientation are definitely a benefit to the advanced orientation-functional optoelectronic applications.

In Situ Fabrication and Static Contact Resistance of CdMoO4 Reinforced Cu Matrix Composites.

Particle-reinforced Cu-based electrical contact materials prepared by traditional powder metallurgical methods suffer the same critical problem, where the agglomeration of the addition phases in the Cu matrix significantly deteriorates the performance of the composites and restricts their application. In this work, CdMoO4/Cu matrix composites were fabricated by an in situ method and followed by a powder metallurgical process. Firstly, CdMoO4/particles formed a nucleus and grew up based on the surfaces of Cu particles, realizing the controllable in situ synthesis of mixed powders with homogeneously dispersed CdMoO4 nanoparticles via a one-step reaction. Secondly, the bulk CdMoO4/Cu composites were fabricated by pressing and sintering and then densified by hot-extrusion and cold rolling processes. The microstructures and properties of the extruded and rolled specimens were characterized, respectively. The results indicated that the rolled CdMoO4/Cu composite exhibited excellent comprehensive properties of electrical conductivity and mechanical properties for electrical contact materials. Moreover, the effects of the contact force on the static contact resistance of the extruded and rolled composites were evaluated in the closed state of the contact materials. It was found that the rolled CdMoO4/Cu contact materials possessed a stable electrical contact characteristic with low and steady contact resistance. This work designed ternary CdMoO4 particles to reinforce Cu-based composites with well-balanced performances by an in situ synthesis method and this strategy can be extended to the design of ternary oxide/metal composites utilized as electrical contact materials.

Hot Deformation Behavior and Processing Maps of ZnSnO3/Cu Composites.

In this work, we designed ternary ZnSnO3 particle-reinforced Cu matrix composites and evaluated the hot deformation behavior of ZnSnO3/Cu composites. The hot deformation characteristics of typical dynamic recrystallization were probed by the resulting true stress-strain curves of ZnSnO3/Cu composites. The influences of deformation conditions, including temperatures (650-850 °C) and strain rates (0.01-5 s-1), on the flow stress of the designed composites were investigated. This revealed that the peak stress increased with the increasing of strain rate and decreasing of temperature. Additionally, the activation energy was calculated to be 237.05 kJ/mol and followed by yielding a constitutive equation for low-stress ZnSnO3/Cu composites. The processing maps established by dynamic materials model theory indicated that the designed composites possessed excellent hot workability, and then the processing parameters (790-850 °C and 0.01-0.04 s-1) of the ZnSnO3/Cu composites were determined for practical industrial production. Our work discloses the deformation behavior of ZnSnO3/Cu matrix composites and extends the rational process design for ternary ceramic/metal materials with excellent hot workability.

Study on Reentry Evaluation Mode for Blood Donors Used to be HBV Reactive in Jiangsu Province / 中国实验血液学杂志

OBJECTIVE@#To evaluate the risk of reentry in HBV reactive blood donors and feasibility of HBV reentry strategy.@*METHODS@#HBsAg+ or HBV DNA+ donors who had been quarantined for more than 6 months in Jiangsu Province could propose for reentry application. Blood samples were routinely screened by dual-ELISA for HBsAg, anti-HCV, HIV Ab/Ag, and anti- Treponema pallidum and those non-reactive ones were tested by minipool nucleic acid testing (NAT) for three times. To identify occult HBV donors, samples of NAT non-reactive were further tested by electrochemiluminescence immunoassay (ECLIA) for HBV seromarkers (including HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb). Donors of only 4 ECLIA patterns were accepted to reentry, including all 5 HBV seromarkers negative, anti-HBs only but having history of hepatitis B vaccine injection, HBcAb only, HBsAb+ / HBcAb+ with HBsAb more than 200 IU/L. Additionally, the detection rate of HBV infection was compared between routine screening mode and ECLIA, as well as the reentry qualified rate of HBsAg+ and HBV DNA+ blood donors.@*RESULTS@#From Oct. 2016 to Aug. 2019, a total of 737 HBV reactive donors had applied for reentry, including 667 HBsAg+ reactive and 70 HBV DNA+ reactive donors. Among 3 screening methods, the highest HBV detection rate (43.15%, 318/737) was observed on ECLIA, while only 4.75% (35/737) on ELISA and 3.12% (23/737) on NAT, respectively. Among 4 qualified patterns of HBV serological markers, the highest proportion was found in the all negative group (22.90%, 155/677), followed by the group with HBsAb+ only and history of hepatitis B vaccine injection (19.35%, 131/677), and the median concentration of HBsAb was 237.7 IU/L. The unqualified rate of HBV DNA+ donors was 82.86%, which was significantly higher than 47.98% of HBsAg+ donors.@*CONCLUSION@#Routine screening tests merely based on ELISA and NAT could miss occult HBV donors and may not be sufficient for blood safety. HBsAb concentration and vaccine injection history should be included in the evaluation of HBV reactive donors who intend to apply for reentry. There is a relatively larger residual risk of occult HBV infection in blood donors quarantined for HBV DNA reactive.

Effect of Pre-Stretch on the Precipitation Behavior and the Mechanical Properties of 2219 Al Alloy.

The influence of pre-stretch on the mechanical properties of 2219 Al alloys sheets were systematically investigated, with the aim of examining the age-strengthening in parts draw-formed from as-quenched sheets. The precipitation was characterized based on differential scanning calorimetry (DSC) analysis and transmission electron microscope (TEM) observation of specimens of as-quenched and quenched-stretched condition to address the influence of pre-stretching. A tensile test was performed to evaluate the effect on mechanical properties. The introduction of pre-stretching endues increased yield strength (YS) and thus can be helpful to exert the potential of the alloy. Peak YS of 387.5 and 376.8 MPa are obtained when specimens pre-stretched for 10% are aged at 150 and 170 °C, respectively, much higher than that obtained in the non-stretched specimens (319.2 MPa). The precipitation of Guinier-Preston zone (G.P. zones) and the transition to θ″ shifts to a lower temperature when pre-stretched is performed. The high density of dislocations developed during the stretching contributes to the acceleration in precipitation. Quench-stretched specimens present a much quicker age-hardening response at the beginning stage, which endue higher peaked yield strength. The yield strength, however, decrease much more quickly due to the recovery that occurs during the aging processes. The study suggested the feasibility of aging draw-formed components of 2219 Al alloy to obtain high strength.

Prevalence of Human T-Cell Lymphotropic Virus Type 1 and 2 among Blood Donors in Jiangsu from 2016 to 2019 / 中国实验血液学杂志

OBJECTIVE@#To investigate the prevalence of human T-cell lymphotropic virus (HTLV) type-I/II infection among voluntary blood donors in Jiangsu (Nanjing, Suzhou, Xuzhou).@*METHODS@#From 2016 to 2019, 408 262 samples of voluntary blood donors from four blood stations in Jiangsu Province (Jiangsu Province Blood Center, Nanjing Red Cross Blood Center, Suzhou Central Blood Station, and Xuzhou Central Blood Station) were screened for HTLV-I/II antibody by ELISA. The positive samples were sent to National Center for Clinical Laboratories for confirmation by RT-PCR and Western blot.@*RESULTS@#The positive rate of HTLV-I/II screened by ELISA was 0.20‰ (82/408 262), and three HTLV-I positive samples were confirmed. The prevalence of HTLV-1 infection was 0.74 per 100 000 (3/408 262). All three donors were female repeated blood donors of childbearing ages.@*CONCLUSION@#Jiangsu is a low prevalence area of HTLV, and a reasonable blood screening strategy for HTLV can further reduce the risk of transfusion-transmitted virus infection.

Analysis of Reasons Causing False Positive of HBsAg Single-ELISA-Reactive in Blood Donors / 中国实验血液学杂志

OBJECTIVE@#To explore the reasons causing the false positive of HBsAg single-ELISA-reactive in blood donors of Jiangsu province so as to provide reference data for the return of blood donors.@*METHODS@#Serological test: HBsAg ELISA parallel detection was performed on 319 444 samples of blood donors from 2014 to 2017; the ECLIA was employed to confirm the single-ELISA-reactive (S/CO≥0.5) samples, the nucleic acid test was used to detect the HBV DNA on the all single-ELISA-reactive samples in 6/8 people mixed/single. Reagent evaluation: the Receiver-Operating-Characteristic curve (ROCC) was drawn by the ECLIA/NAT results as the gold standard, and the diagnostic performance of reagents A and B under different cut-off was evaluated.@*RESULTS@#A total of 227 (0.71‰) single-ELISA-reactive samples were detected among 319 444 blood donors, including 39 cases (17.2%) of positive HBsAg and 12 cases (5.3%) of positive HBV DNA; Under the maximum YI, the COI (1.0) employed by the manufacturer recommendation has a better diagnostic value than laboratory COI (0.5), and the capability of reagent A was better than that of reagent B (AUC: 0.661 vs 0.632; Youden: 0.329 vs 0.297), but the specificity of both reagents was restricted (＜60%). Under the maximum YI, the best cut-off value of reagents A and B were 2.4 and 1.4 COI, respectively. Compared with the cut-off value of manufacturer, the sensitivity of reagents A decreased by 33% and the false positive rate decreased by 60% while the sensitivity of reagent B increased by 140% and the false positive rate increased by 36%, respectively.@*CONCLUSION@#The false positive of HBsAg single-ELISA-reactive in blood donors is caused by the limited specificity of ELISA reagent and the setting of COI values. According to ROCC maximum YI method, the COI can be set as 2.4 COI and (0.5-1.4) COI for reagent A and B to reduce false positive rate.

Sero-prevalence of Babesia infection among voluntary blood donors in Jiangsu Province / 中国血吸虫病防治杂志

Objective To evaluate the sero-positivity of Babesia infection in voluntary blood donors in Jiangsu region, so as to provide the evidence for transfusion safety. Methods A total of 950 blood samples were collected from voluntary blood donors in Jiangsu Provincial Blood Center from February to May, 2017, and detected by double antigen sandwich ELISA targeting peptides derived from B. microti-secreted antigen 1 (BmSA1). The positive samples were confirmed by microscopy and nested-PCR to determine parasitemia. The prevalence of anti-BmSA1 was analyzed between/among different genders, ages and occupations of the blood donors. Results Of the 950 blood screened samples, 5 were positive for anti-BmSA1, and the sero-prevalence of Babesia infection was 0.53%. The 5 samples were all negative by microscopy and nested-PCR. There were no gender- (χ2 = 0.01, P =0.92) or age-specific differences (χ2 = 0.11, P = 0.95) in the sero-prevalence of Babesia infection; however, there was an occupation-specific difference detected in the sero-prevalence of Babesia infection (χ2 = 11.93, P < 0.05). Conclusion Babesia infection is detected in voluntary blood donors in Jiangsu region, which should be paid much attention.

Sero-prevalence of Babesia infection among voluntary blood donors in Jiangsu Province / 中国血吸虫病防治杂志

Objective To evaluate the sero-positivity of Babesia infection in voluntary blood donors in Jiangsu region, so as to provide the evidence for transfusion safety. Methods A total of 950 blood samples were collected from voluntary blood donors in Jiangsu Provincial Blood Center from February to May, 2017, and detected by double antigen sandwich ELISA targeting peptides derived from B. microti-secreted antigen 1 (BmSA1). The positive samples were confirmed by microscopy and nested-PCR to determine parasitemia. The prevalence of anti-BmSA1 was analyzed between/among different genders, ages and occupations of the blood donors. Results Of the 950 blood screened samples, 5 were positive for anti-BmSA1, and the sero-prevalence of Babesia infection was 0.53%. The 5 samples were all negative by microscopy and nested-PCR. There were no gender- (χ2 = 0.01, P =0.92) or age-specific differences (χ2 = 0.11, P = 0.95) in the sero-prevalence of Babesia infection; however, there was an occupation-specific difference detected in the sero-prevalence of Babesia infection (χ2 = 11.93, P < 0.05). Conclusion Babesia infection is detected in voluntary blood donors in Jiangsu region, which should be paid much attention.

Evaluation of the Cutoff of Anti-HCV Antibody Enzyme-Linked Immunosorbent Assay in 7 Blood Station Laboratories / 中国实验血液学杂志

OBJECTIVE@#To evaluate the necessity and suitability of the anti-HCV ELISA teot gray zone setted up by 7 blood station laboratories.@*METHODS@#7 blood station laboratories were coded as 1, 2, 3, 4, 5, 6 and 7 respectively; 8 kinds of ELISA reagents were coded as A, B, C, D, E, F, G and H respectively. 1 or 2 of 8 ELISA reagents produced by different manufactories were used to detect the anti-HCV in specimens of same group by 7 blood station laboratories; the Westen blot was used to detect the specimens with difference of detected results so as to difine the serological status of specimens. The true positive rate of specimens detected by laboratories and gray zone-comfirined positive rate of specimens were accounted so as to analyze the necessity of setting up the gray zone for anti-HCV ELISA test of 7 blood station laboratories; the optimal cut-off value for anti-HCV ELISA test was determined in 7 blood station laborafories by ROC curve and the changes of sensitivity and specificity of 3 different cut-off value(laboratory work cut-off value, manifactory-recommended cun-off value and optimal cut-off value) were compared so as to analyze the suitability of gray zone for anti-HCV ELISA test in 7 blood station laboratories.@*RESULTS@#The true positive rate detected by 7 blood station laboratories, out of which coded 1 laboratory used 2 kinds of coded A, B reagents was 95.40%(1A), 99.23% (1B), 94.25% (2C), 96.17% (3D), 98.08% (4E), 96.93% (5F), 97.32%(6G) and 93.10%(7H). Except for 2C(94.25%) and 7H(93.10%), the true positive rate detected by laboratoies which not sutted up gray zone, the gray zone-con-firmed positive rate in 6 blood station laboratories setted up gray zone: was 0.00%, 0.00%, 21.43%, 0.00%, 0.00%, 0.00% and 38.89%. The comparison of 3 different cut-off valuces by ROC curve showed that the anti-HCV cut-off values in 5 laboratories(1B, 2C, 4E, 5F and 6G) were as follows: optimal cut-off value＞manufactory recommeded cut-off value＞laboratory work cut-off value, thus use of manufactory-recommeded cut-off value abreadly has reached the high sensitivity requinements for laboratory screening; however, the optimal cut-off value in laboratories 1A, 3B and 7H, thas the appropriate gray zone should be used. In 6 laboratories setting up gray zone, the gensitivity in 3D, 7H laboratories only a little improved (1.60% and 2.70% raspectively) in Eamparison between laboratory work cut-off value and manufactorg-recommeded cut-off value; moreover, the sensitivity in other laboratories not is changed, but the specificity decreased (0.20%-0.50%).@*CONCLUSION@#In addition to setting up the appropriate gray zone in laboratories 1A, 3D and 5H, the gray zone in other laboratories may be cancelled. Even in the same laboratory, the setting up the gray zone also should be scientifically assessed, the same scale cannot be blindly used, thus appropniate strategies should be established.

Microstructure Evolution and the Resulted Influence on Localized Corrosion in Al-Zn-Mg-Cu Alloy during Non-Isothermal Ageing.

A non-isothermal ageing process was proposed for an Al-Zn-Mg-Cu alloy aiming to accommodate the slow heating/cooling procedure during the ageing of large components. The evolution of microstructure and microchemistry was analyzed by using transmission electron microscopy, high-angle annular dark field imaging, and energy dispersive spectrometry. The age-hardening of the alloy was examined to evaluate the strengthening behavior during the non-isothermal process. The corrosion behavior was investigated via observing the specimens immersed in EXCO solution (solution for Exfoliation Corrosion Susceptibility test in 2xxx and 7xxx series aluminum alloys, referring ASTM G34-01). Secondary precipitation was observed during the cooling stage, leading to increased precipitate number density. The distribution of grain boundary precipitates transits from discontinuous to continuous at the cooling stage, due to the secondary precipitation’s linking-up effect. The solutes’ enrichment on grain boundary precipitates and the depletion in precipitate-free zones develops during the heating procedure, but remains invariable during the cooling procedure. The corrosion in NIA (Non-isothermal Ageing) treated specimens initiates from pitting and then transits to intergranular corrosion and exfoliation corrosion. The transition from pitting to intergranular corrosion is very slow for specimens heated to 190 °C, but accelerates slightly as the cooling procedure proceeds. The transition to exfoliation corrosion is observed to be quite slow in all specimens in non-isothermal aged to over-aged condition, suggesting a corrosion resistance comparable to that of RRA condition.

Effects of dopants on the adhesion and electronic structure of a SnO2/Cu interface: a first-principles study.

Doping has been adopted as a versatile approach for tuning the adhesion of metal oxide/metal interfaces. Understanding the mechanism of doping at the interface adhesion on the atomic and electronic scale is crucial for the rational design and optimization of metal oxide/metal composites. In this work, we have investigated the effects of dopants on the adhesion of SnO2/Cu interfaces through first-principles calculations. Firstly, O-terminated a SnO2(110)/Cu(111) interface (denoted as I) was considered and the work of separation values of the interfaces with various dopants (Mo, Sb, Ti, Zn and Cu) were calculated to evaluate the interface adhesion strength. It was demonstrated that low-valence dopants (Zn2+ and Cu2+) enhance the adhesion strength of interface I, while high-valence dopants (Mo6+ and Sb5+) play the opposite role. Secondly, the strengthening effects of low-valence dopants were further verified in four candidate interfacial models with different atomic structures (denoted as II-V). The work of separation values indicated that the adhesion of all of the interfaces involved could be enhanced by low-valence doping. The electronic structure of the interface was demonstrated through density of states, charge density and charge density difference analyses. The results revealed that upon low-valence doping, the holes facilitate charge transfer between Cu and SnO2, which generates strong covalent bonds across the interface and thus significantly enhances the interface adhesion. This work not only provides insight into rational doping to enhance the adhesion of SnO2/Cu composites but can also be expanded upon for the design of other metal oxide/metal composites with strong interface adhesion.

Surface characterization and degradation behavior of polyimide films induced by coupling irradiation treatment.

The degradation behavior of polyimide in extreme environments, especially under coupling treatment, directly determines the service life of several key components in spacecraft. In this research, the combined effect of a high energy electron beam (1.2 MeV), heavy tensile stress (50 MPa) and constant high temperature (150 °C) was taken into account to study the surface modification and degradation behavior of polyimide films. By analyzing surface morphology, microstructural evolution and mechanical behavior of polyimide films after coupling treatment, the results indicated that the coupling treatment led to severe breakage of chemical bonds and decrease of surface quality. Meanwhile, new chemical bonds of C-C, CH2-O and C[triple bond, length as m-dash]N formed after coupling treatment. Additionally, a high dose of electron beam during coupling experiments contributed to the formation of an oxide layer, surface defects and even volatile gases in the outer layer of the polyimide film. This was attributed to the significant scissioning of molecular chains in polyimide films and corresponding chemical reactions between free radicals and oxygen in air. Consequently, the irradiation-load-heating coupling treatment led to a remarkable drop in viscoelastic properties and mechanical performance of polyimide films.

Photoresponse Enhancement in Monolayer ReS2 Phototransistor Decorated with CdSe-CdS-ZnS Quantum Dots.

ReS2 films are considered as a promising candidate for optoelectronic applications due to their direct band gap character and optical/electrical anisotropy. However, the direct band gap in a narrow spectrum and the low absorption of atomically thin flakes weaken the prospect for light-harvesting applications. Here, we developed an efficient approach to enhance the performance of a ReS2-based phototransistor by coupling CdSe-CdS-ZnS core-shell quantum dots. Under 589 nm laser irradiation, the responsivity of the ReS2 phototransistor decorated with quantum dots could be enhanced by more than 25 times (up to ∼654 A/W) and the rising and recovery time can be also reduced to 3.2 and 2.8 s, respectively. The excellent optoelectronic performance is originated from the coupling effect of quantum dots light absorber and cross-linker ligands 1,2-ethanedithiol. Photoexcited electron-hole pairs in quantum dots can separate and transfer efficiently due to the type-II band alignment and charge exchange process at the interface. Our work shows that the simple hybrid zero- and two-dimensional hybrid system can be employed for photodetection applications.

Chemical Vapor Deposition Growth of Degenerate p-Type Mo-Doped ReS2 Films and Their Homojunction.

Substitutional doping of transition metal dichalcogenide two-dimensional materials has proven to be effective in tuning their intrinsic properties, such as band gap, transport characteristics, and magnetism. In this study, we realized substitutional doping of monolayer rhenium disulfide (ReS2) with Mo via chemical vapor deposition. Scanning transmission electron microscopy demonstrated that Mo atoms are successfully doped into ReS2 by substitutionally replacing Re atoms in the lattice. Electrical measurements revealed the degenerate p-type semiconductor behavior of Mo-doped ReS2 field effect transistors, in agreement with density functional theory calculations. The p-n diode device based on a doped ReS2 and ReS2 homojunction exhibited gate-tunable current rectification behaviors, and the maximum rectification ratio could reach up to 150 at Vd = -2/+2 V. The successful synthesis of p-type ReS2 in this study could largely promote its application in novel electronic and optoelectronic devices.

Infection status of HBV, HCV and HIV in voluntary blood donors of Chinese Nanjing area during 2010-2013 / 中国实验血液学杂志

This study was purposed to understand the infection of HBV, HCV, HIV among the voluntary blood donors and the epidemic trend in infectious population in Chinese Nanjing area, and to guide the mobilization and recruitment of blood donors. A total of 199777 whole blood samples of voluntary blood donors were tested by ELISA, the nucleic acid technology (NAT) combined detection (HBV-DNA, HCV-RNA, HIV-RNA) was added for detection of the samples with HBsAg,anti-HCV, anti-HIV at least unilateral negative donors from June 10, 2010 to June 9, 2013 years, and these statistic data were analyzed. Every HIV reactive sample(HIV-antibody and/or HIV-RNA) was sent to be confirmed in the Centers for Disease Control and Prevention in Nanjing. The results showed that the voluntary donors' infection rate of HBsAg, anti-HCV, anti-HIV were 0.45%, 0.28%, 0.11% respectively; NAT positive rate was 0.07%, 32 cases were confirmed with anti-HIV positive, in which 30 cases were male (6 cases were repeated blood donors) and 2 cases were female, 3 cases were unconfirmed, in which 2 cases were males and 1 case was female. The statistical analysis demonstrated that the difference of unqualitative rate of HBsAg, anti-HCV, anti-HIV was statistically significant between the first-time and repeated blood donors.It is concluded that the positive rate of anti-HCV and anti-HIV displayed a declining trend year by year in Nanjing voluntary blood donation population from June 10,2010 to June 9, 2013 years. The unqualitative rate of HBsAg and NAT increased with the age increasing, while that of anti-HCV, anti-HIV decreased with age increasing. The unqualitative rate of the repeated blood donors is far lower than that of the first-time blood donors. The ELISA positive rate of anti-HIV testing in females is higher than that in males, but the confirmed positive rate of male is significantly higher than that of female. Therefore the consulting skills before donating should be improved, concerning the link of recruiting donors, focusing on strengthening the first-time donors' consultation, evaluating and developing the fixed voluntary blood donors, and vigorously popularizing NAT technology in blood screening to improve the blood safety effectively.

Analysis on HIV infection status of voluntary blood donors in Chinese Nanjing area from 2003 to 2013 / 中国实验血液学杂志

This study was purposed to analyze HIV infections status among the unpaid blood donation population in Chinese Nanjing area from 2003 to 2013, to understand the HIV antibody positive and/or HIV-RNA positive population characteristics in order to provide evidence for recruiting strategy of blood donation without compensation. The whole blood samples of unpaid donors and the platelet donors were tested by ELISA, from June 2010 the NAT test was added for the samples that were ELISA test with unilateral negative. Every HIV reactive sample (HIV-antibody and/or HIV-RNA) was sent to confirm in the Centers for Disease Control and Prevention in Nanjing, including 1 case of enzyme bilateral positive and HIV-RNA reactivity has been sentenced as indeterminacy; another 1 case of enzyme bilateral negative and HIV-RNA reactive was sent to the Centers for Disease Control and Prevention in Jiangsu Province to test nucleic acid quantification to be positive; The unpaid donor HIV screening results from 2003 to 2013 in Chinese Nanjing area were analysed statistically. The results showed that from 2003 to 2013 years 641401 unpaid blood donors were tested,out of them 57 cases were contirmed to be HIV antibody positive (HIV-1),the total positive rate was 8.89/100 000. Since 2010 years, the HIV antibody positive rate increased significantly (P < 0.01), then it was stable until to 2012 years, the HIV antibody positive rate was 15.43/100 000. In the 2013 year, the HIV antibody positive rate was 10.03/100 000. The HIV antiboby positive rates in male and female were 13.25: 1. The years of male cases were 18-30 that accounted for 56.14%, and the years of male cases were 31-40 that accounted for 31.58%. The men who first time donated blood were 46 cases and accounted for 80.70%. The men who donated blood again were 11 cases and accounted for 19.30%. The men who donated blood on streets of blood donation accounted for 80.70% and their HIV antibody positive rate was 11.88/100 000. The men who donated blood in the plan organization of donators were 8.78%, and their HIV antibody possitive rate was 2.33/100 000. The HIV antibody positive rate were different in the different times and different donation types, and were statistical significance (P < 0.01). It is concluded that based on the present status of HIV antibldy positive rate in Chinese Nanjing area, the HIV antibody possitive donors are more observed in the first blood donation population, especially in the higher educated young men. This situation or tendency indicates that the voluntary blood donors should be organized or selected from low risk population, and should popularize the knowlege of unpaid blood donation, especiatly the knowlege of AIDS, strengthen cosulting work on the mobile donation points in streets before donating blood, and should establish the cyber-database to ensure blood safety.

Biomechanical study on open fracture model with plate fixation compared with closed fracture model with intramedullary nail fixation in rats / 中国骨伤

<p><b>OBJECTIVE</b>To compare biomechanical effect of the closed fracture model with intramedullary nail fixation and the open fracture model with plate fixation in rats.</p><p><b>METHODS</b>Forty 8-week-old Spragu-Dawley male rats were divided into two groups randomly. Left femoral shaft closed fractures model was created in 20 rats, and treated with intramedullary nail. Other 20 rats received open osteotomy on the left femoral shaft, and were fixed by plate. Rats were sacrificed and draw the materials at 4, 6, 8 and 12 weeks in batch. Across section area and volume of callus were measured, peak load, restoration rate of peak load were tested. The biomechanical efficency of two methods of femoral shaft fracture fixation were compared.</p><p><b>RESULTS</b>The difference of surgical duration was statistically significant between two groups (P < 0.001). At 4, 6, 8 and 12 weeks, the difference of peak load, restoration rate of peak load, volume and area of callus was also statistically significant between two groups (P < 0.05).</p><p><b>CONCLUSION</b>Open fracture model with plate fixation led to delayed healing compared with closed fracture model with intramedullary nail. However, open fracture model with plate fixation model could be a valuable research tool to study the healing consequences of cortical bone, which may provide insight into the pathogenesis and ideal treatment of fractures or nonunions.</p>

Biomechanical differences of embalmed and PMMA femurs / 医用生物力学

Objective To compare the differences in biomechanical properties of embalmed and PMMA femurs under axial loads, so as to provide a more reliable and unified femoral model for replacement. Methods Ten embalmed femurs and ten PMMA femurs were selected, and each femur was instrumented with 49 strain gauges totally on the medial and lateral side. The axial load was applied dynamically up to a maximum of 1.2 kN, and the strain of each strain gauge and load displacement curve were recorded. Results The strain distributions on two types of femur were similar, and the load displacement presented a linear relationship, but the vertical displacements under different loads were significantly different (P<0.05). The axial stiffness value of PMMA femur and embalmed femur were (259.84±24.63) and (600.40±78.56) N/mm, respectively, showing significant difference (P<0.01). The strain concentration parts at the proximal part of two femurs were the same, but the average strain value of the PMMA femur was significantly different from that of the embalmed femur (strain gauge No. 1~5: PMMA femur (-3 420.63±373.31) με, embalmed femur (-1 289.42±417.89) με; strain gauge No. 26~27: PMMA femur (1 748.67±193.98) με, embalmed femur (673.42±104.49) με; strain gauge No. 7~10: PMMA femur (-4 028.25±267.27) με, embalmed femurs (-1 139.01±288.83) με; strain gauge No. 30~36: PMMA femur (1 599.02±194.68) με, embalmed femurs (590.52±153.18) με, P<0.01). The strain concentration parts at the distal part of the two femurs were different. The medial and lateral parts of strain transformation between positive and negative of PMMA femurs were similar to embalmed femurs. The strain-load curves of strain gauge No. 2, 26, 6, 29, 8 and 33 indicated a linear relationship, but the strain value of the two femurs had significant differences (P<0.05). Conclusions The PMMA femur can replace the embalmed femur to a certain degree in biomechanical experiments on the upper part of femur. Due to the difficulty of obtaining fresh femurs, the PMMA femurs provide a more reliable and unified femoral model for replacement.

Aqueous solution synthesis of CaF2 hollow microspheres via the ostwald ripening process at room temperature.

Nearly monodispersive CaF2 hollow microspheres were synthesized by a facile aqueous solution route from the mixed aqueous solutions of CaCl2, Na2WO4, and NaF at room temperature. The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy (TEM), high-resolution transmission electron microscopy, and N2 adsorption-desorption techniques. The CaF2 hollow microspheres have an average diameter of about 1.5 microm and a hollow interior of 0.5 microm. The shell is composed of numerous single-crystalline nanoparticles with diameter of about 20 nm. The morphologies and diameters of the CaF2 products are strongly dependent on the experimental parameters, such as the concentration of the aqueous NaF solution and the reaction temperature. The synthetic experiments indicate that the growth process of CaF2 hollow microspheres involves first the formation of CaWO4 solid microspheres and then the formation of CaF2 solid microspheres through the reaction between CaWO4 and F(-) ions controlled by the difference of the solubility product for CaWO4 and CaF2. Phenomenological elucidation based on TEM observations and XRD patterns of intermediate products at different precipitation stages indicates that the formation mechanism for the CaF2 hollow microspheres is related to the Ostwald ripening mechanism. N2 adsorption-desorption measurement shows that the CaF2 hollow microspheres possess a high Brunauer-Emmett-Teller surface area and porosity properties. The synthetic procedure is straightforward and represents a new example of the Ostwald ripening mechanism for the formation of inorganic hollow structures in an aqueous solution at room temperature.