[Establishment of acute graft-versus-host disease model after non-myeloablative haploidentical peripheral blood stem cell transplantation in aged mice]

Objective: To establish an acute graft-versus-host disease (aGVHD) model in aged mice after non-myeloablative haploidentical peripheral blood stem cell transplantation (haplo-PSCT). Methods: C57BL/6 (H-2b) male mice aged 6-8 weeks were used as donor mice, and CB6F1 (H-2b×d) female mice aged 14-16 months were used as recipient mice. The donor mice were injected subcutaneously with rehuman granulocyte-colony stimulating factor (rhG-CSF) 5 days before transplantation for hematopoietic stem cell mobilization.The recipient mice were divided into control group (CG), spleen cell low-dose group (SL), spleen cell medium-dose group (SM) and spleen cell high-dose group (SH) according to random number table method, with 16 rats in each group, all of which received total linear accelerator X-ray irradiation (TBI) with a total dose of 6 Gy. Peripheral blood mononuclear cells (PBMC) and spleen cells of different doses (0.5×107/each, 1.0×107/each and 2.0×107/each in SL group, SM group and SH group, respectively) were transfused through the tail vein within 4 hours after TBI, and only the same amount of normal saline was transfused in CG group. After transplantation, the survival and weight changes of mice in each group were observed for 30 days, and the changes of blood routine were monitored regularly. Mice peripheral blood was collected 21 days after transplantation to detect the chimerism rate of the donor. Hematoxylin-eosin staining was performed on the skin, liver and colon of mice 21 days after transplantation to analyze the histopathological changes of aGVHD target organs. Results: All the mice in each group were successfully transplanted. After TBI, the weight and activity of mice in all groups decreased, and the phenomenon of bone marrow suppression appeared. During the observation period, all mice in CG group and SL group survived, 3 mice in SM group died with survival time of (26.0±5.8) days, and 6 mice in SH group died with survival time of (20.9±7.3) days. The body weight of mice in SH group was lower than that in CG group, SL group and SM group 21days after transplantation [(25.0±0.7), (25.5±0.4), (25.0±1.4) vs (20.8±0.8) g, all P<0.05]. Compared with CG group, SL group and SM group, the levels of leukocyte, erythrocyte, hemoglobin and platelet in SH group decreased 21 days after transplantation (all P<0.05). There was no significant difference in donor chimerism rate among SL group, SM group and SH group [(95.8%±0.8%), (95.5%±1.4%) and (95.1%±1.3%), respectively, all P>0.05]. Compared with CG group, SL group and SM group, the tissue structure of aGVHD target organs in SH group was severely damaged, with a large number of inflammatory cells infiltratedand higher histopathological scores than SL group and SM group (all P<0.05). Conclusion: For aging CB6F1 mice, after 6 Gy TBI pretreatment with linear accelerator X-ray, PBMC (1×107/each) and spleen cells (2.0×107/each) were injected to successfully induce aGVHD model after non-myelablative haplo-PSCT.

Improved Measurement of the Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

Reactor neutrino experiments play a crucial role in advancing our knowledge of neutrinos. In this Letter, the evolution of the flux and spectrum as a function of the reactor isotopic content is reported in terms of the inverse-beta-decay yield at Daya Bay with 1958 days of data and improved systematic uncertainties. These measurements are compared with two signature model predictions: the Huber-Mueller model based on the conversion method and the SM2018 model based on the summation method. The measured average flux and spectrum, as well as the flux evolution with the ^{239}Pu isotopic fraction, are inconsistent with the predictions of the Huber-Mueller model. In contrast, the SM2018 model is shown to agree with the average flux and its evolution but fails to describe the energy spectrum. Altering the predicted inverse-beta-decay spectrum from ^{239}Pu fission does not improve the agreement with the measurement for either model. The models can be brought into better agreement with the measurements if either the predicted spectrum due to ^{235}U fission is changed or the predicted ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu spectra are changed in equal measure.

Precision Measurement of Reactor Antineutrino Oscillation at Kilometer-Scale Baselines by Daya Bay

We present a new determination of the smallest neutrino mixing angle θ_{13} and the mass-squared difference Δm_{32}^{2} using a final sample of 5.55×10^{6} inverse beta-decay (IBD) candidates with the final-state neutron captured on gadolinium. This sample is selected from the complete dataset obtained by the Daya Bay reactor neutrino experiment in 3158 days of operation. Compared to the previous Daya Bay results, selection of IBD candidates has been optimized, energy calibration refined, and treatment of backgrounds further improved. The resulting oscillation parameters are sin^{2}2θ_{13}=0.0851±0.0024, Δm_{32}^{2}=(2.466±0.060)×10^{-3}  eV^{2} for the normal mass ordering or Δm_{32}^{2}=-(2.571±0.060)×10^{-3}  eV^{2} for the inverted mass ordering.

First Measurement of High-Energy Reactor Antineutrinos at Daya Bay

This Letter reports the first measurement of high-energy reactor antineutrinos at Daya Bay, with nearly 9000 inverse beta decay candidates in the prompt energy region of 8-12 MeV observed over 1958 days of data collection. A multivariate analysis is used to separate 2500 signal events from background statistically. The hypothesis of no reactor antineutrinos with neutrino energy above 10 MeV is rejected with a significance of 6.2 standard deviations. A 29% antineutrino flux deficit in the prompt energy region of 8-11 MeV is observed compared to a recent model prediction. We provide the unfolded antineutrino spectrum above 7 MeV as a data-based reference for other experiments. This result provides the first direct observation of the production of antineutrinos from several high-Q_{β} isotopes in commercial reactors.

[Influences of leukocytes in patients with type 2 diabetes and periodontitis to the effects of periodontal treatment on glycemic control]

Objective: To analyze the influences of leukocytes on improving blood glucose control in patients with type 2 diabetes mellitus (T2DM) and periodontitis after periodontal mechanical therapy. Methods: Thirty-five patients visiting Peking University Third Hospital from March 2011 to August 2012, as well as thirty-four patients visiting Peking University Hospital of Stomatology from March 2011 to August 2012 and December 2016 to December 2018 were selected in this research. These subjects were non-smokers, and with moderate to severe chronic periodontitis and T2DM. The full set of periodontal examinations including probing depth (PD), attachment loss (AL), bleeding index (BI) and plaque index (PLI) were conducted. Besides, counts of white blood cells (WBC), parameters of glucose and lipids metabolites such as fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL) and low density lipoprotein (LDL) in serum were examined before treatment. Then, oral hygiene instruction, scaling and root planing (SRP) were carried out. Three months after SRP, the baseline examinations were repeated in all patients. According to the baseline leukocyte counts, the patients were divided into subgroups: low WBC group (WBC<6.19×109/L) and high WBC group (WBC≥6.19×109/L). Paired t-test for comparison of changes after treatment, analysis of co-variance for comparing the intervention effects between subgroups, and multifactor Iogistic regression analysis were performed. Results: Three months after SRP, all periodontal indexes were significantly improved in both groups. Leukocyte counts decreased significantly in high WBC group (7.64±1.51 vs. 6.89±1.53, P=0.008). In high WBC group, HbA1c (7.67±1.35 vs. 7.18±1.09, P=0.001) and LDL (3.28±0.76 vs. 2.67±0.85, P=0.042) decreased significantly, while there were no such differences in low WBC group. Influence of leukocyte level on HbA1c (OR=0.12, P=0.038) and LDL (OR=0.15, P=0.001) improvement was statistically significant. Hierarchical analysis showed such improvement notably perform in female [HbA1c (OR=0.30, P=0.021), LDL (OR=0.34, P=0.001)] and severe periodontitis group [HbA1c (OR=0.15, P=0.025), LDL (OR=0.24, P=0.017)]. Through interaction test, female and leukocyte counts at baseline had relative excess risk affecting the effect of periodontal intervention on HbA1c (P=0.036) and LDL (P=0.005). Conclusions: SRP could significantly improve the blood glucose and lipid control in patients who had T2DM and chronic periodontitis with relative higher leukocytes level. Female patients with severe periodontitis showed more obviously effects.

Joint Determination of Reactor Antineutrino Spectra from ^{235}U and ^{239}Pu Fission by Daya Bay and PROSPECT

A joint determination of the reactor antineutrino spectra resulting from the fission of ^{235}U and ^{239}Pu has been carried out by the Daya Bay and PROSPECT Collaborations. This Letter reports the level of consistency of ^{235}U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent. The combined analysis reduces the degeneracy between the dominant ^{235}U and ^{239}Pu isotopes and improves the uncertainty of the ^{235}U spectral shape to about 3%. The ^{235}U and ^{239}Pu antineutrino energy spectra are unfolded from the jointly deconvolved reactor spectra using the Wiener-SVD unfolding method, providing a data-based reference for other reactor antineutrino experiments and other applications. This is the first measurement of the ^{235}U and ^{239}Pu spectra based on the combination of experiments at low- and highly enriched uranium reactors.

[Analysis of Dimethyltryptamine in Captured Suspicious Substances：Three Case Reports]

Abstract.

Gamma-Ray Observation of the Cygnus Region in the 100-TeV Energy Region

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

No pulsed radio emission during a bursting phase of a Galactic magnetar

Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances^1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources^4-13, but no convincing evidence has been collected so far¹⁴. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft γ-ray bursts¹⁵. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft γ-ray/hard-X-ray flare^18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-γ-ray repeater (SGR) bursts were detected in γ-ray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.

Improved Constraints on Sterile Neutrino Mixing from Disappearance Searches in the MINOS, MINOS+, Daya Bay, and Bugey-3 Experiments

Searches for electron antineutrino, muon neutrino, and muon antineutrino disappearance driven by sterile neutrino mixing have been carried out by the Daya Bay and MINOS+ collaborations. This Letter presents the combined results of these searches, along with exclusion results from the Bugey-3 reactor experiment, framed in a minimally extended four-neutrino scenario. Significantly improved constraints on the θ_{μe} mixing angle are derived that constitute the most constraining limits to date over five orders of magnitude in the mass-squared splitting Δm_{41}^{2}, excluding the 90% C.L. sterile-neutrino parameter space allowed by the LSND and MiniBooNE observations at 90% CL_{s} for Δm_{41}^{2}<13  eV^{2}. Furthermore, the LSND and MiniBooNE 99% C.L. allowed regions are excluded at 99% CL_{s} for Δm_{41}^{2}<1.6 eV^{2}.

[The (18)F-FDG positron emission tomography integrated computed tomography associate with intravoxel incoherent motion in prediction of EGFR expression in lung cancer]

Objective: To discuss the diagnostic value potential of (18)F-FDG PET/CT and intravoxel incoherent motion (IVIM) in genotype EGFR of lung cancer. Methods: A total of 116 cases proved pathologically pulmonary space occupying lesions (72 males, 44 females; age range was 31-85 years; 37 cases of high differentiation; 53 cases of middle differentiation, 26 cases of low differentiation) were prospectively collected from August 2017 to March 2019 in Henan Provincial People's Hospital. EGFR gene detection was performed in 50 patients (wild type 20 cases, mutant 30 cases). Whole body PET/CT and lung MR-imaging were performed before treatment in all patients. Comparison of PET/CT, IVIM semi-quantitative parameters between positive and negative of EGFR by Student-t test or Mann-Whitney U test. Evaluation diagnostic efficacy of each parameter to EGFR by drawing ROC curves. The optimum diagnostic threshold, specificity, sensitivity, positive predictive value, negative predictive value and the diagnostic accuracy were calculated. The diagnostic accuracy of (18)F-FDG PET/CT combined with IVIM was calculated. Results: The quantitative parameters standard intake(SUV), apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D(*)), perfusion fraction (f) were 8.7±3.5, (1.59±0.26) ×10(-3) mm(2)/s, (1.04±0.12)×10(-3) mm(2)/s, (3.9±3.0)×10(-2) mm(2)/s, 0.43±0.16 and the above parameters of the wild group were 14.3±3.3, (1.34±0.26)×10(-3) mm(2)/s, (0.89±0.12)×10(-3) mm(2)/s, (3.5±2.5)×10(-2) mm(2)/s, 0.40±0.11, respectively. The difference of quantitative parameters SUV (t=4.196, P=0.0001), ADC (t=2.502, P=0.0018), D (t=3.158, P=0.006) between the EGFR mutant group and the wild group was statistically significant. The difference of quantitative parameters D(*) (t=0.361, P=0.721), f (t=0.627, P=0.536) was not statistically significant. ROC curve was drawn and the area under the curves for diagnosis of EGFR mutations by SUV, ADC, D, D(*), f was 0.880, 0.755, 0.820, 0.575, 0.550. The diagnostic accuracy of these parameters above mentioned was 80.0%, 76.7%, 73.3%, 66.7%, 53.3% respectively. The diagnostic accuracy of SUV combined with ADC, D values was 83.3% and 80.0%. Conclusion: PET/CT and IVIM have certain diagnostic value for EGFR typing of lung cancer gene.

[Epidemiological analysis of the deaths with antiretroviral treatment among adult HIV/AIDS patients in Liangshan Yi Autonomous Prefecture from 2005 to 2015]

Objective: To analyze the deaths with antiretroviral treatment among adult HIV/AIDS patients in Liangshan Yi Autonomous Prefecture from 2005 to 2015, in order to understand the epidemiological characteristics and to further reduce the mortality rate in Liangshan Prefecture. Methods: The relevant information was collected through the Management Database of Antiretroviral Treatment from the National AIDS Comprehensive Prevention Information System. Results: From 2005 to 2015, a total of 14 219 adult HIV/AIDS patients received antiretroviral treatment and 1 425 death cases were reported during the treatment. The cause of death was mainly AIDS-related diseases (58.9%), and the cumulative mortality rate was 10.02%. Gender, age, the way of infection, duration of antiretroviral therapy, clinical stage when received antiretroviral therapy, and CD(4)(+) T lymphocyte levels were factors for the mortality rate (P<0.001). The mortality increased with older age, higher initiation clinical stage and lower level of CD(4)(+) T lymphocyte. Among the death cases, 82.6% were male, 1 182 (82.9%) were married or cohabited, most aged between 30-39 years old (48.6%). At the initial point of receiving antiretroviral therapy, 49.7% of the cases with CD(4)(+)T lymphocytes levels< 200/μl, 61.2% of the deaths cases were>1 000 copies/ml during the last viral load test, and 16.2% of deaths were ≥500/μl in the last CD(4)(+)T lymphocyte test; 44.5% of deaths were received antiretroviral treatment within one year. Conclusion: Early and timely antiretroviral therapy should be carried out. It is necessary to strengthen the propaganda of antiretroviral therapy and to improve the management quality of follow-up information of antiretroviral therapy case files, and to improve the medication compliance of patients.

Identification of Tiletamine, Zolazepam and Their Metabolites in Drug Facilitated Sexual Assault by GC-QTOF-MS

Objective To identify tiletamine, zolazepam and their metabolites in samples from drug facilitated sexual assault by gas chromatography-quadrupole time of flight mass spectrometry （GC-QTOF-MS）. Methods Urine samples of victims were collected, and detected by GC-QTOF-MS after liquid-liquid extraction and concentration. The molecular formula of fragments ions was identified by determination of accurate mass numbers, to detect related substances. Results Tiletamine, zolazepam, three metabolites of tiletamine and two metabolites of zolazepam were identified in urine samples from actual cases. Conclusion GC-QTOF-MS provides abundant and accurate information of fragment ions mass numbers, which can be used for qualitative identification of tiletamine, zolazepam and their metabolites in drug facilitated sexual assault.

Extraction of the ^{235}U and ^{239}Pu Antineutrino Spectra at Daya Bay

This Letter reports the first extraction of individual antineutrino spectra from ^{235}U and ^{239}Pu fission and an improved measurement of the prompt energy spectrum of reactor antineutrinos at Daya Bay. The analysis uses 3.5×10^{6} inverse beta-decay candidates in four near antineutrino detectors in 1958 days. The individual antineutrino spectra of the two dominant isotopes, ^{235}U and ^{239}Pu, are extracted using the evolution of the prompt spectrum as a function of the isotope fission fractions. In the energy window of 4-6 MeV, a 7% (9%) excess of events is observed for the ^{235}U (^{239}Pu) spectrum compared with the normalized Huber-Mueller model prediction. The significance of discrepancy is 4.0σ for ^{235}U spectral shape compared with the Huber-Mueller model prediction. The shape of the measured inverse beta-decay prompt energy spectrum disagrees with the prediction of the Huber-Mueller model at 5.3σ. In the energy range of 4-6 MeV, a maximal local discrepancy of 6.3σ is observed.

[Clinical research of HLA-haploidentical peripheral hematopoietic stem cell transplantation following reduced intensity conditioning regimen with hematological malignancy patients over 50 years old]

目的

分析减低剂量预处理单倍型外周血造血干细胞移植（RIC-haplo-PBSCT）治疗50岁以上恶性血液肿瘤患者的疗效。

方法

18例50岁以上恶性血液肿瘤患者纳入研究，男8例，女10例，中位年龄52（50~66）岁；急性髓系白血病（AML）8例，慢性髓性白血病（CML）2例，骨髓增生异常综合征（MDS）5例，急性淋巴细胞白血病（ALL）2例，急性NK细胞白血病（ANKL）1例；采用FAB+ATG（氟达拉滨+阿糖胞苷+白消安+兔抗人胸腺细胞免疫球蛋白）减低剂量预处理方案，输注供者高剂量非去T细胞外周血造血干细胞（PBSC），应用强化移植物抗宿主病（GVHD）预防方案及感染防控措施。

结果

16例患者在移植后15 d获得完全供者嵌合，其中1例在移植后1个月发生移植排斥，其余2例在移植后15 d为混合嵌合并于移植后1个月发生移植排斥。急性GVHD发生率为61.1%（95%CI 49.6%~72.6%），Ⅱ~Ⅳ度急性GVHD发生率为35.4%（95%CI 21.1%~49.7%），Ⅲ/Ⅳ度急性GVHD发生率为13.8%（95%CI 4.7%~22.9%）。2年慢性GVHD累积发生率为38.2%（95%CI 25.5%~50.9%），未发生广泛型慢性GVHD。中位随访14.5（3~44）个月，2年总生存率、无病生存率分别为72.6%（95%CI 60.1%~85.1%）、63.7%（95%CI 49.2%~78.2%），2年累积复发率为31.2%（95%CI 16.5%~45.9%），2年非复发死亡率为12.5%（95%CI 4.2%~20.8%）。

结论

RIC-haplo-PBSCT治疗50岁以上恶性血液肿瘤患者可获得较好的疗效。

[Relationship between gH genotyping and clinical characteristics of children with congenital cytomegalovirus infection]

Objective: To study the relationship between human cytomegalovirus (HCMV) envelope glycoprotein gene H and clinical features of children with congenital cytomegalovirus infection. Methods: A cohort study was conducted. Newborns diagnosed with congenital cytomegalovirus infection, hospitalized in the Department of Neonatology and Neonatal Intensive Care Unit (NICU) of the Children's Hospital, Zhejiang University School of Medicine, were included from July 2013 to December 2015.HCMV-DNA gH typing in urine, sputum or blood was conducted. Patients then were divided into gH1 group and gH2 group according to gH genotypes. Patients' data during hospitalization in newborn and 3-5 years of follow-up were collected.The relationships between gH genotype and clinical manifestations, laboratory examinations, hearing loss and neurological prognosis were analyzed by chi-square test, t test and non-parametric test. Results: A total of 21 cases were enrolled as congenital HCMV infection and followed-up for 3-5 years. Among them, 14 (67%) were gH1 type and 7 (33%) were gH2 type. No mixed infection was found. In the two groups, there were no significant differences in the ratio of males (9/14 vs. 3/7,P=0.397), or birth weight ((2 609±686) vs. (3 021±451) g, t=-1.436, P=0.167). Gestational age of gH1 group was younger than that of gH2 group (38 (29-40) vs. 39(38-40) weeks, Z=-2.18, P=0.029). Moderate to severe hearing loss detected by neonatal auditory brainstem response were found in 40 ears (20 cases). It was higher in gH1 group than that in gH2 group (4/22 vs.0/18, χ(2)=5.145, P=0.023). In the imaging examination of the nervous system, the Alarcon score of gH1 group was lower than that of gH2 group (0.4±0.3 vs. 1.3±1.1, t=-2.459,P=0.024).No significant statistical difference was found in the probability of motor or language development lag in gH2 group and gH1 group (4/7 vs.4/14, P=0.346). Conclusions: Compared with gH2 infection, gH1 infection in children has a younger gestational age. The major type of hearing loss in neonatal period is gH1 infection. Children with gH2 congenital infections are more likely to suffer from nervous systems damage.

Measurement of the Electron Antineutrino Oscillation with 1958 Days of Operation at Daya Bay

We report a measurement of electron antineutrino oscillation from the Daya Bay Reactor Neutrino Experiment with nearly 4 million reactor ν[over ¯]_{e} inverse β decay candidates observed over 1958 days of data collection. The installation of a flash analog-to-digital converter readout system and a special calibration campaign using different source enclosures reduce uncertainties in the absolute energy calibration to less than 0.5% for visible energies larger than 2 MeV. The uncertainty in the cosmogenic ^{9}Li and ^{8}He background is reduced from 45% to 30% in the near detectors. A detailed investigation of the spent nuclear fuel history improves its uncertainty from 100% to 30%. Analysis of the relative ν[over ¯]_{e} rates and energy spectra among detectors yields sin^{2}2θ_{13}=0.0856±0.0029 and Δm_{32}^{2}=(2.471_{-0.070}^{+0.068})×10^{-3}  eV^{2} assuming the normal hierarchy, and Δm_{32}^{2}=-(2.575_{-0.070}^{+0.068})×10^{-3}  eV^{2} assuming the inverted hierarchy.

Effects of Mo contents on the microstructure, properties and cytocompatibility of the microwave sintered porous Ti-Mo alloys

The porous Ti-Mo alloys were prepared by microwave sintering, and the effects of Mo contents on the pore structure, phase composition, compressive strength, elastic modulus, bending strength, corrosion resistance and cytocompatibility of porous Ti-Mo alloys were investigated. The results show that the porous Ti-Mo alloys are composed of α phase and β phase, and the volume fraction of β phase increases with increasing the Mo contents. The amount of Kirkendall pores distributed over the porous Ti-Mo alloys skeleton increases with increasing the Mo contents, which greatly increases the porosities and pore sizes of the porous Ti-Mo alloys. Correspondingly, all of the compressive strength, elastic modulus and bending strength of the porous Ti-Mo alloys decrease with increasing the Mo contents. The porous Ti-Mo alloys present excellent corrosion resistance in the Hank's solution due to the oxidation film of TiO₂, MoO₂ and MoO₃ naturally formed on the surface, and the Mo contents have no obvious effect on the corrosion resistance. The cell viabilities of the porous Ti-Mo alloys are higher than 94%, indicating the porous Ti-Mo alloys possess favorable cytocompatibility. Moreover, the porous Ti-Mo alloys are beneficial to the spread, proliferation and differentiation of osteoblast-like cells, and the Mo contents have no significant effect on the cytocompatibility of the porous Ti-Mo alloys.

Discovery of Small Molecule Ligands for MALAT1 by Tuning an RNA-Binding Scaffold

Structural studies of the 3'-end of the oncogenic long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) confirmed a unique triple-helix structure. This structure enables accumulation of the transcript, and high levels of MALAT1 are found in several cancers. Here, we synthesize a small molecule library based on an RNA-binding scaffold, diphenylfuran (DPF), screen it against a variety of nucleic acid constructs, and demonstrate for the first time that the MALAT1 triple helix can be selectively targeted with small molecules. Computational analysis revealed a trend between subunit positioning and composition on DPF shape and intramolecular interactions, which in turn generally correlated with selectivity and binding strengths. This work thus provides design strategies toward chemical probe development for the MALAT1 triple helix and suggests that comprehensive analyses of RNA-focused libraries can generate insights into selective RNA recognition.

Thymidine kinase 1 combined with CEA, CYFRA21-1 and NSE improved its diagnostic value for lung cancer

AIMS

Thymidine kinase 1 (TK1) is a tumor biomarker in human malignancies. The purpose of this study was to evaluate the diagnostic efficiency of this marker for lung cancer using the combined analysis of carcinoembryonic antigen (CEA), cytokeratin-19 fragment (CYFRA21-1), neuron specific enolase (NSE) and TK1.

MAIN METHODS

From 2013 to 2014, 147 patients with lung cancer and 228 patients with lung benign diseases who were admitted to our hospital were reviewed. Peripheral blood samples were collected for the detection of TK1, CEA, CYFRA21-1 and NSE. The diagnostic value of each marker was analyzed using receiver operating characteristic (ROC) curves and logistic regression equations.

KEY FINDINGS

The serum levels of TK1, CEA, CYFRA21-1 and NSE were significantly higher than those in patients with lung benign diseases (all P<0.05). The TK1 concentration was dependent on TNM stage (P=0.005). The ROC curve analyses showed that the diagnostic value of TK1 combined with CEA, CYFRA21-1 and NSE in lung cancer was significantly higher than that of each biomarker alone (all P<0.0001). In addition, TK1 combined with CEA, CYFRA21-1, or NSE could also improve the diagnosis of the squamous cell carcinoma, adenocarcinoma and small cell lung cancer subtypes, respectively.

SIGNIFICANCE

The combined detection of TK1 and the other three markers significantly improved the diagnosis of lung cancer. Furthermore, the detection of TK1 combined with that of CYFRA21-1, CEA or NSE increased the diagnostic value of TK1 for lung squamous cell carcinoma, adenocarcinoma and SCLC, respectively.

[Therapeutic effect of combined use of FGF1-loaded nano-liposomes and ultrasound-targeted microbubble destruction technique on treating rats with experimental diabetic cardiomyopathy]

Objective: The therapeutic effect of acid fibroblast growth factor 1(FGF1) on rats with diabetic cardiomyopathy (DCM) was evaluated by using nano-liposomes combined with ultrasound-targeted microbubble destruction technique (UTMD). Methods: The FGF1-loaded nano-liposomes were prepared by water-in-water emulsion method combined with lyophilization technique.TypeⅠdiabetes model was induced by intraperitoneal injection of streptozotocin (STZ, 70 mg/kg) in 60 male SD rats.Sixteen weeks later, diabetic rats were randomly divided into: placebo group (saline treatment), FGF1 group, FGF1-loaded nano-liposomes group, and FGF1-loaded nano-liposomes plus UTMD group (n=15 each). After two weeks of intervention followed by 2 weeks intervention stop, all rats underwent cardiac catheterization, and the left ventricular end-systolic pressure (LVESP), left ventricular end-diastolic pressure (LVEDP) and the maximal increase/decrease rate of left ventricular pressure (LV±dp/dtmax) were measured.Then, the rats were sacrificed and myocardial tissue were obtained for Masson trichrome staining, TUNEL apoptotic staining and CD31 immunohistochemistry staining to quantify myocardial collagen fraction (CVF), cardiac myocyte apoptotic index and myocardial microvascular density (MVD). Results: (1)Scanning electron microscope results revealed good morphology and FGF1 encapsulation efficiency (84.3±2.8)% with high stability and dispensability of FGF1 loaded nano-liposomes.(2)The hemodynamic evaluation showed that LVESP, LV + dp/dt(max) and LV -dp/dt(max) were all significantly higher, while LVEDP was significantly lower in the FGF1-loaded nano-liposome+ UTMD group than in DCM group, FGF1 solution group, and FGF1 nano-liposome group(all P<0.05). (3)The Masson trichrome staining demonstrated that CVF was significantly higher in all DCM groups than in control group and was significantly lower in the FGF1-loaded nano-liposome+ UTMD group than in DCM group, FGF1 solution group, and FGF1 nano-liposome group (all P<0.05). (4)The CD31 immunohistochemical staining results showed that MVD was significantly lower in all DCM groups than in control group and was significantly higher in the FGF1-loaded nano-liposome+ UTMD group than in DCM group, FGF1 solution group, and FGF1 nano-liposome group (all P<0.05). (5)The TUNEL results showed that apoptotic index was significantly higher in all DCM groups than in control group and was significantly lower in the FGF1-loaded nano-liposome + UTMD group than in DCM group, FGF1 solution group, and FGF1 nano-liposome group (all P<0.05). Conclusion: FGF1 nano-liposomes combining with UTMD technique can significantly improve cardiac functions and attenuate myocardial CVF and apoptosis and enhance myocardial MVD in DCM rats.

[Porphyromonas gingivalis FimA genotype distribution among periodontitis patients with type 2 diabetes]

OBJECTIVE

To investigate the distribution differences of Porphyromonas gingivalis(Pg) FimA genotypes between periodontitis patients with and without type 2 diabetes for a better understanding of the relationship between diabetes and periodontitis.

METHODS

Questionnaires and detailed periodontal examinations(6 sites per tooth) were conducted in 80 subjects with moderate-severe chronic periodontitis in the Department of Periodontology, Peking University School and Hospital of Stomatology. There were 40 type 2 diabetic patients and 40 systemicly healthy patients enrolled respectively. The periodontal parameters including plaque index(PLI), probing depth(PD), bleeding index(BI), attachment loss(AL) by 6 sites per tooth and numbers of missing teeth were also recorded. Pooled subgingival plaque samples using pocket method with Whatman No3 filterpaper were collectedat each of the 6 sites from one incisor and one molar. Pg and its FimA genotype distributions were investigated using DNA extrctedfrom plaque samples by PCR.

RESULTS

Diabetic patients had a significantly higher score of PLI[2.35(0.58) vs 1.64(0.76),P<0.05] , while rest of periodontal indexes observed(PD, BI and AL) did not differ significantly between diabetic patients and systemicly healthy controls(P>0.05). The detection rate of Pg did not show statistically significant difference between the two groups(50% vs 60%,P>0.05). However, the proportion of FimA Ⅱ was significantly higher in diabetic group than systemicly healthy group(80% vs 42%,P<0.05).

CONCLUSIONS

Type 2 diabetic patients were prone to be infected by highly virulent strains of Pg: FimA ⅡPg.

Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 GW_{th} reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective ^{239}Pu fission fractions F_{239} from 0.25 to 0.35, Daya Bay measures an average IBD yield σ[over ¯]_{f} of (5.90±0.13)×10^{-43}  cm^{2}/fission and a fuel-dependent variation in the IBD yield, dσ_{f}/dF_{239}, of (-1.86±0.18)×10^{-43}  cm^{2}/fission. This observation rejects the hypothesis of a constant antineutrino flux as a function of the ^{239}Pu fission fraction at 10 standard deviations. The variation in IBD yield is found to be energy dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1σ. This discrepancy indicates that an overall deficit in the measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes ^{235}U, ^{239}Pu, ^{238}U, and ^{241}Pu. Based on measured IBD yield variations, yields of (6.17±0.17) and (4.27±0.26)×10^{-43}  cm^{2}/fission have been determined for the two dominant fission parent isotopes ^{235}U and ^{239}Pu. A 7.8% discrepancy between the observed and predicted ^{235}U yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.

[Correlation between the CT features and malignancy risk of small (≤5 cm) gastric stromal tumors]

Objective: To evaluate the correlation between computed tomography (CT) features and malignancy risk category of small (≤5 cm) gastric stromal tumors (GST), in order to provide an image reference for preoperative assessment and intraoperative pathological diagnosis. Methods: Eighty-three patients with surgically and pathologically proven GST (≤5 cm) between January 2011 and November 2015 were recruited, and their clinical, pathological and CT data were retrospectively analyzed. According to the pathological results and malignancy risk category, the patients were divided into 2 groups, the benign biological behavior group (very low and low risk) and malignant biological behavior group (intermediate and high risk). The clinical, pathological and CT imaging findings of the two groups were analyzed. Based on the tumor diameter, the receiver operating characteristic curve (ROC) was applied to evaluate the sensitivity, specificity and the best cut-off point for distinguishing the malignancy risk between the two groups. Results: The lobulation and ulceration of the tumors presented statistically significant difference for the malignancy risk between the two groups (χ(2)=6.273 and 4.163, respectively; all P<0.05), but there was no significant difference in the sex, clinical symptoms, serum ferritin, tumor site, growth pattern, cystis degeneration and calcification (all P>0.05). No statistically significant differences were detected for the tumor CT value, arterial CT value, venous CT value, degrees of enhancement in arterial phase (DEAP), enhancement in portal venous phase (DEPP), and patient's age for distinguishing the malignancy risk between the two groups (all P>0.05). On the other hand, significant differences were found in the maximum diameter (Dmax) of tumor and the minimum diameter (Dmin) of tumor (t=-3.256 and -3.466, respectively; all P<0.05). When the cut-off point of Dmax was 1.6 cm, the area under the ROC curve, sensitivity and specificity were 0.704, 92.3% and 75.4%, respectively. When the cut-off point of Dmin was 1.5 cm, the area under the ROC curve, sensitivity and specificity were 0.713, 88.5% and 71.9%, respectively. Conclusion: CT features of the GST (≤5 cm) may predict, before surgery, the malignancy risk of small gastric stromal tumors, and provide the an image reference for preoperative assessment and intraoperative pathological diagnosis of the disease.

[Value of CT imaging in the differentiation of gastric leiomyomas from gastric stromal tumors]

Objective: To explore the application value of CT imaging in differentiating gastric stromal tumors (GST) from gastric leiomyomas (GLMs). Methods: CT images of patients with GST (n=65) or GLMs (n=13, maximum diameter of tumor ≤5 cm) proved by surgery and pathology were retrospectively analyzed. The tumor size, location, contour, growth pattern, degree and pattern of enhancement, calcification, necrosis, surface ulceration, lymph nodes, and patient clinical data were evaluated by two independent reviewers. Receiver operating characteristic (ROC) curves were employed to assess the measurement and calculation parameters in the differentiation of GST and GLMs. Results: Between the GST and GLMs groups, there was no statistically significant difference in the contour, growth pattern, calcification, surface ulceration, and patient's sex (P>0.05). CT values of in plain scans, degree of enhancement in arterial phase (DE1), size, location and pattern of enhancement were found to be different between GST and GLMs (P<0.05). When the cutoff value of the maximum tumor diameter was 3.2 cm, the area under ROC curve, sensitivity and specificity were 0.707, 92.3%(12/13) and 60.6%(40/66), respectively. When the cutoff value of age was 59 years, the area under ROC curve, sensitivity and specificity were 0.773, 92.3% (12/13) and 46.2% (30/65), respectively. Taking the cutoff value of 10.9 HU as the degree of enhancement in arterial phase (DE1), the area under ROC curve, sensitivity and specificity were 0.774, 84.6% (11/13) and 77.3% (51/66), respectively. Using a cutoff value of 30.3 HU, the sensitivity, specificity, and the area under ROC curve were 84.6% (11/13), 65.2% (43/66), and 0.731, respectively. Conclusions: CT examination in addition to clinical data can be very helpful for the differential diagnosis of GLMs from GSTs in maximum diameter ≤5 cm.

Limits on Active to Sterile Neutrino Oscillations from Disappearance Searches in the MINOS, Daya Bay, and Bugey-3 Experiments

Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^{2}2θ_{μe} are set over 6 orders of magnitude in the sterile mass-squared splitting Δm_{41}^{2}. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Δm_{41}^{2}<0.8  eV^{2} at 95%  CL_{s}.

Improved Search for a Light Sterile Neutrino with the Full Configuration of the Daya Bay Experiment

This Letter reports an improved search for light sterile neutrino mixing in the electron antineutrino disappearance channel with the full configuration of the Daya Bay Reactor Neutrino Experiment. With an additional 404 days of data collected in eight antineutrino detectors, this search benefits from 3.6 times the statistics available to the previous publication, as well as from improvements in energy calibration and background reduction. A relative comparison of the rate and energy spectrum of reactor antineutrinos in the three experimental halls yields no evidence of sterile neutrino mixing in the 2×10^{-4}≲|Δm_{41}^{2}|≲0.3  eV^{2} mass range. The resulting limits on sin^{2}2θ_{14} are improved by approx imately a factor of 2 over previous results and constitute the most stringent constraints to date in the |Δm_{41}^{2}|≲0.2  eV^{2} region.

[Comparisons of occurrence and curative effect of interstitial pneumonia after the related HLA-haploidentical and HLA-matched sibling peripheral blood hematopoietic stem cell transplantation]

OBJECTIVE

To compare occurrence and curative effect of interstitial pneumonia (IP) of patients with malignant hematologic disease after related HLA-haploidentical peripheral blood stem cell transplantation without T-cell depletion (RHNT-PBSCT) and non T cell-depleted HLA-matched sibling peripheral blood stem cell transplantation (MSNT-PBSCT).

METHODS

109 patients with malignant hematologic disease as the research cases received RHNT-PBSCT from January 2006 to December 2014, which were compared with 125 patients treated with MSNT-PBSCT during the same period to determine the occurrence of IP and curative effect produced by ganciclovir and joint adrenal glucocorticoids.

RESULTS

The incidences of IP in RHNT-PBSCT and MSNT-PBSCT groups were 15.60%(17/109) and 13.60%(17/125) (P=0.150), respectively; both the effective rates were 76.47%(13/17) (P=0.536), the difference was not statistically significant. Single factor analysis showed that acute graft versus host disease was a risk factor for the occurrence of IP after RHNT-PBSCT (P=0.001).

CONCLUSION

The incidence of IP in patients with malignant hematologic disease after RHNT-PBSCT didn' t increase when compared with patients after MSNT-PBSCT. The curative effects of the two groups were equivalent after priority to ganciclovir and joint adrenal glucocorticoids.

Association of CYP1A1 MspI polymorphism with oral cancer risk in Asian populations: a meta-analysis

Numerous studies regarding the association between the CYP1A1 MspI polymorphism and oral cancer risk in Asian populations have shown controversial results. To get a more precise estimation of this relationship, we conducted a comprehensive meta-analysis. PubMed, the Cochrane Library, Elsevier Science Direct, Web of Knowledge, the Chinese National Knowledge Infrastructure, VIP, and Wan Fang Med Online were searched. Pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated using fixed-effects or random-effects models. Heterogeneity among studies was assessed using the Cochran Q test and I(2) statistics. Twelve articles including 1925 oral cancer patients and 2335 controls were ultimately included in the meta-analysis. Overall, the meta-analysis showed that the CYP1A1 MspI polymorphism was associated with oral cancer risk in Asians (m1/m1 vs m2/m2: OR = 0.46, 95%CI = 0.30-070, POR = 0.000; m1/m1 vs m1/m2+m2/m2: OR = 0.70, 95%CI = 0.51-0.98, POR = 0.037; m1/m1+m1/m2 vs m2/m2: OR = 0.48, 95%CI = 0.35-0.65, POR = 0.000). Subgroup analyses showed that the control source (hospital-based or population-based), the genotyping method [polymerase chain reaction (PCR) or PCR-restriction fragment length polymorphism], the country in which the study was conducted, and Hardy-Weinberg equilibrium (Yes or No) were positively related to the association. Sensitivity analysis suggested that the overall results showed no significant change in three genetic models when any one study was removed, and publication bias was undetected by the Egger test. The CYP1A1 MspI polymorphism may be associated with oral cancer risk in Asian populations.

[The clinical value of vestibular autorotation test in the diagnosis of otogenic vertigo]

Objective:To explore the clinical value of vestibular autorotation test (VAT) in the treatment for otogenic vertigo patients. Method:One hundred and twenty-nine definite otogenic vertigo patients were included. All patients underwent the VAT and caloric test (CT). The results were analyzed statistically. Result:In VAT examination, 89 (69.0%) cases were abnormal. In CT examination, 56 (43.4%) cases were abnormal. In the contrast test of VAT and CT, VAT results were abnormal in 47 (36.4%) patients and CT results were abnormal in 14 (10.9%) patients. The number of patients whose both VAT and CT results were abnormal was 42 (32.6%). The total number of patients with various abnormal results was 103 (79.8%). According to statistical analysis, the abnormal result rate of VAT was higher than that of CT. The abnormal result rate of both VAT and CT was higher than that of each single test. There was statistic significance in the difference (χ²=1.670, P<0.05). Conclusion:For otogenic vertigo patients, their abnormal result rate of VAT is higher than that of CT. VAT and CT can be mutually complementary. The combination of VAT and CT can help to understand the function of semicircular canal in the general and provide reference for the treatment of otogenic vertigo diseases.

[Frequency and position characteristics of the vestibular dysfunction in vestibular neuritis patients]

Objective:To investigate frequency and position characteristics of the vestibular dysfunction in vestublar neuritis patients. Method:Colaric test (CT), head impulse test (HIT), cervical vestibular evoked myogenic potential (cVEMP) and ocular vestibular evoked myogenic potential (oVEMP) were applied in 43 vestublar neuritis patients to assess their vestublar dysfunction. Superior vestublar nerve (S-VN), inferior vestibular nerve (I-VN), total vestibular nerve (T-VN) and each vestibular end organ incidence rate were calculated and statistically analyzed. Result:CT incidence rate (93.0%) was statistically higher than that of HIT (72.1%) (P<0.01). Total frequency incidence rate (72.1%) was statistically higher than that of low frequency (20.9%) (P<0.01). No high frequency only case was observed. The incidence rate of S-VN only, I-VN only and T-VN was 44.2%, 4.7% and 51.2% respectively. Among them, the incidence rate of I-VN was significantly lower than the others (P<0.01). The incidence rate of vestibular end organs was 17.4% (S-SCC), 44.2% (H-SCC), 20.9% (P-SCC), 39.5% (utricule) and 26.7% (saccule) respectively. The incidence rate of H-SCC was remarkably higher than the other semicircular canals (P<0.01). The difference between utricule and saccule was not statistically significant. Conclusion:The semicricular canal dysfunction in vestibular neuritis patients mainly involves total frequency of vestibular function, low frequency is more common than high frequency. Total vestibular nerve and single S-VN are mostly involved in vestibular neuritis.

Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay

This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9 GWth nuclear reactors with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296 721 and 41 589 inverse β decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55±0.04) ×10(-18)  cm(2) GW(-1) day(-1) or (5.92±0.14) ×10(-43)  cm(2) fission(-1). This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is 0.946±0.022 (0.991±0.023) relative to the flux predicted with the Huber-Mueller (ILL-Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2σ over the full energy range with a local significance of up to ∼4σ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.

New measurement of antineutrino oscillation with the full detector configuration at Daya Bay

We report a new measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9×10^{5} GW_{th}  ton days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six ^{241}Am-^{13}C radioactive calibration sources reduced the background by a factor of 2 for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of sin^{2}2θ_{13} and |Δm_{ee}^{2}| were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave sin^{2}2θ_{13}=0.084±0.005 and |Δm_{ee}^{2}|=(2.42±0.11)×10^{-3}  eV^{2} in the three-neutrino framework.

Analysis of prognostic factors for infantile rotavirus infection

In this study, we investigated the prognostic factors of infantile rotavirus (RV) infection. A total of 102 infants with RV enteritis were divided into 2 groups according to the standards of improvement and cure at the time of discharge from the hospital: improvement group (N = 58; 47 males and 11 females with an average age of 15.19 ± 5.03 months) and the cure group (N = 44; 34 males and 10 females with an average age of 10.02 ± 4.92 months). Both groups were phlebotomized for the detection of serum glutamic oxaloacetic aminotransferase, creatine kinase-MB, and lactate dehydrogenase. Prognostic factors and clinical data were analyzed by univariate and multivariate logistic analysis. Among the 102 cases of RV infection, 58 were cured and 44 were improved. Univariate analysis showed that the 2 groups were significantly different in age, feeding pattern, concentrations of serum glutamic oxaloacetic aminotransferase, creatine kinase-MB, and lactate dehydrogenase, and central nervous system damage. Logistic regression analysis showed that age, feeding, and central nervous system damage were significant independent prognostic factors for RV enteritis (P < 0.05). There were no statistical differences in gender, course of disease, and respiratory infection (P < 0.05). Both myocardial and hepatic damages presented a temporary feature in the infants and had no significant influence on prognosis. Age, feeding pattern, and central nervous system damage are significant independent prognostic factors for RV infection. These factors should be carefully considered in clinical practice.

Microstructure, mechanical properties and superelasticity of biomedical porous NiTi alloy prepared by microwave sintering

Porous NiTi alloys were prepared by microwave sintering using ammonium hydrogen carbonate (NH4HCO3) as the space holder agent to adjust the porosity in the range of 22-62%. The effects of porosities on the microstructure, hardness, compressive strength, bending strength, elastic modulus, phase transformation temperature and superelasticity of the porous NiTi alloys were investigated. The results showed that the porosities and average pore sizes of the porous NiTi alloys increased with increasing the contents of NH4HCO3. The porous NiTi alloys consisted of nearly single NiTi phase, with a very small amount of two secondary phases (Ni3Ti, NiTi2) when the porosities are lower than 50%. The amount of Ni3Ti and NiTi2 phases increased with further increasing of the porosity proportion. The porosities had few effects on the phase transformation temperatures of the porous NiTi alloys. By increasing the porosities, all of the hardness, compressive strength, elastic modulus, bending strength and superelasticity of the porous NiTi alloys decreased. However, the compressive strength and bending strength were higher or close to those of natural bone and the elastic modulus was close to the natural bone. The superelastic recovery strain of the trained porous NiTi alloys could reach between 3.1 and 4.7% at the pre-strain of 5%, even if the porosity was up to 62%. Moreover, partial shape memory effect was observed for all porosity levels under the experiment conditions. Therefore, the microwave sintered porous NiTi alloys could be a promising candidate for bone implant.

Search for a light sterile neutrino at Daya Bay

A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored.

Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay

A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9  GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3)  eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.

Effect of micro-arc oxidation surface modification on the properties of the NiTi shape memory alloy

In this paper, the effects of micro-arc oxidation (MAO) surface modification (alumina coatings) on the phase transformation behavior, shape memory characteristics, in vitro haemocopatibility and cytocompatibility of the biomedical NiTi alloy were investigated respectively by differential scanning calorimetry, bending test, hemolysis ratio test, dynamic blood clotting test, platelet adhesion test and cytotoxicity testing by human osteoblasts (Hobs). The results showed that there were no obvious changes of the phase transformation temperatures and shape memory characteristics of the NiTi alloy after the MAO surface modification and the coating could withstand the thermal shock and volume change caused by martensite-austenite phase transformation. Compared to the uncoated NiTi alloys, the MAO surface modification could effectively improve the haemocopatibility of the coated NiTi alloys by the reduced hemolysis ratio, the prolonged dynamic clotting time and the decreased number of platelet adhesion; and the rough and porous alumina coatings could obviously promote the adherence, spread and proliferation of the Hobs with the significant increase of proliferation number of Hobs adhered on the surface of the coated NiTi alloys (P < 0.05).

Observation of electron-antineutrino disappearance at Daya Bay

The Daya Bay Reactor Neutrino Experiment has measured a nonzero value for the neutrino mixing angle θ(13) with a significance of 5.2 standard deviations. Antineutrinos from six 2.9 GWth reactors were detected in six antineutrino detectors deployed in two near (flux-weighted baseline 470 m and 576 m) and one far (1648 m) underground experimental halls. With a 43,000 ton-GWth-day live-time exposure in 55 days, 10,416 (80,376) electron-antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to expected number of antineutrinos at the far hall is R=0.940±0.011(stat.)±0.004(syst.). A rate-only analysis finds sin(2)2θ(13)=0.092±0.016(stat.)±0.005(syst.) in a three-neutrino framework.

Simultaneously improving yield under drought stress and non-stress conditions: a case study of rice (Oryza sativa L.)

Drought is the most important factor limiting rice productivity in the rainfed areas of Asia. In this study, 48 pyramiding lines (PLs) and their recurrent parent, IR64, were evaluated over two years for their yield performances and related traits under severe drought stress at the reproductive stage (RS), the vegetative stage (VS) and irrigated control in order to understand the relationship between drought tolerance (DT) and yield potential (YP) in rice and their underlying mechanisms. When compared with IR64, all PLs had significantly improved DT to RS and 36 PLs also had significantly improved DT to VS. In addition, 17 PLs had higher YP than IR64 and the remaining 31 PLs had a similar YP IR64 under irrigated conditions. Detailed characterization of the PLs revealed three possible mechanisms that functioned together to contribute to their improved DT. The most important mechanism was dehydration avoidance (DA), characterized by significantly higher growth rate and biomass of all PLs than IR64 under stress and no reduction in biomass under control conditions. The second mechanism was efficient partitioning, characterized by improved harvest index in all PLs compared with IR64, resulting primarily from heavier grain weight and/or higher spikelet fertility under control conditions, which was the major constituent of the improved YP in the 17 best performing PLs. Drought escape (DE) by accelerated heading under drought was the third mechanism that contributed to DT of the PLs to RS. The considerable variation in the measured traits among the PLs with similar levels of DT and YP implies the complex genetic control of the mechanisms for DT/YP and offers opportunities to improve DT and YP further by fine-tuning of a small number of QTLs segregating among the PLs using MAS. Finally, our results indicate that selection for yield plus some secondary traits under appropriate type(s) of stress and non-stress conditions similar to the target environments are critically important for improving both DT and YP in rice.

Chemical analysis of silica doped hydroxyapatite biomaterials consolidated by a spark plasma sintering method

Silica (SiO(2)) and the silicate-based biomaterials play an important role due to their in vitro and in vivo biological response. The present study synthesized a novel nano-structured amorphous silica doped hydroxyapatite (HA) via an aqueous precipitation route. HA was prepared with 0, 1, 3 and 5 wt% silica, which are comparable to the measured silicon content of natural bone. After spray drying into micron sized powders, the silica doped HA (SiHA) powders were consolidated at 1000 degrees C with a dwell time of 3 min using a spark plasma sintering (SPS) technique. X-ray diffraction analysis showed a main apatite phase with minor secondary beta-tricalcium phosphate (beta-TCP) was observed in the as-consolidated SiHA compacts. Substitution of PO(4)(3-) by SiO(4)(4-) in the apatite structure resulting in a small increase in the lattice parameters in both a-axis and c-axis of the unit cell were identified by X-ray photoelectron spectrometer (XPS) analysis and Raman spectrometer investigation. The cell culture in vitro investigation demonstrated that the presence of silicon in the SPS consolidated compacts contributed to the relatively high cell proliferation ability when compared with phase pure HA.

Osteoblast interactions with various hydroxyapatite based biomaterials consolidated using a spark plasma sintering technique

This study investigated the osteoblast behaviors on various hydroxyapatite based biomaterials that were consolidated at 1100 degrees C for 3 min by a spark plasma sintering technique. The osteoblasts from human fetal osteoblast cell line were cultured in the medium on the various biomaterials surfaces (HA, RF21, 1SiHA, and 5SiHA) to assess the cell morphology and proliferation as well as cell differentiation (alkaline phosphatase activity). Moreover, the bone gamma-carboxyglutamic protein or osteocalcin in the medium were determined at different periods of culture. The present results indicated that the amount of osteocalcin in the medium decreased during the periods of culture. The highest osteocalcin production obtained from the biomaterial 5SiHA after cell culture for 2 days demonstrated that the presence of silica in the biomaterials enhanced the cell differentiation by the rapid release of silicate and calcium ions.