ABSTRACT
Recently a dark matter-electron (DM-electron) paradigm has drawn much attention. Models beyond the standard halo model describing DM accelerated by high energy celestial bodies are under intense examination as well. In this Letter, a velocity components analysis (VCA) method dedicated to swift analysis of accelerated DM-electron interactions via semiconductor detectors is proposed and the first HPGe detector-based accelerated DM-electron analysis is realized. Utilizing the method, the first germanium based constraint on sub-GeV solar reflected DM-electron interaction is presented with the 205.4 kg·day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5-15 keV/c^{2}, achieving a 3 orders of magnitude improvement comparing with previous semiconductor experiments. In the light mediator scenario, the strongest laboratory constraint for DM lighter than 0.1 MeV/c^{2} is presented. The result proves the feasibility and demonstrates the vast potential of the VCA technique in future accelerated DM-electron analyses with semiconductor detectors.
ABSTRACT
We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4 kg·day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80 MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90 MeV/c^{2} with heavy mediators and m_{χ} larger than 100 MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.
Subject(s)
Electricity , ElectronsABSTRACT
A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (χ+Aâν+A) and DM-nucleus 3â2 scattering (χ+χ+AâÏ+A), have been analyzed with an energy threshold of 160 eVee. No significant signal was found; thus new limits on the DM-nucleon interaction cross section are set for both models at the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10^{-46} cm^{2} (90% C.L.) at DM mass of 10 MeV/c^{2}. For the DM-nucleus 3â2 scattering scenario, limits are extended to DM mass of 5 and 14 MeV/c^{2} for the massless dark photon and bound DM final state, respectively.
Subject(s)
Cell Nucleus , PhotonsABSTRACT
We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m_{V}) from 10 to 300 eV/c^{2} in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m_{V} from 0.1 to 4.0 keV/c^{2} are set from 449.6 kg-day data, with a minimum of κ=1.3×10^{-15} at m_{V}=200 eV/c^{2}.
ABSTRACT
We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6 GeV/c^{2} among WIMP AM measurements to date.
ABSTRACT
We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}â¼7×10^{-35} cm^{2} for TI analysis at m_{χ}â¼50-180 MeV/c^{2}, and 3×10^{-32}â¼9×10^{-38} cm^{2} for AM analysis at m_{χ}â¼75 MeV/c^{2}-3.0 GeV/c^{2}.
ABSTRACT
We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36} cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5 GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2 GeV/c^{2}.
ABSTRACT
A novel differential interference contrast microscope (DICM) is proposed in this research. It is constituted by inserting a Savart shear prism between the objective and sample of a polarising microscope having a rotatable analyser as the phase-shifter, and it is with the ability to enhance image contrast using the principle of shearing interferometry. This letter is to introduce the configuration, interpret the interference patterns and present the experimental setup of the DICM. In addition, this letter is to display the experimental results from the uses of the setup; the results demonstrate the validity and ability of the DICM.
ABSTRACT
Objective: To carry out a prospective cohort study of combined intra-operative radiotherapy for centrally located hepatocellular carcinomas (HCC) and to observe the safety and postoperative complications. Methods: A total of 79 patients with centrally located HCC who underwent hepatectomy were divided into two groups: experimental group (combined with targeted intra-operative radiotherapy, 32 cases) and control group (single surgical operation, 47 cases). Patients in the experimental group received intra-operative electron radiotherapy after tumor resection, while patients in the control group received to intra-operative electron radiotherapy.The haemorrhagia amount and operation time during the operation, intra-operative liver function and the recovery of liver and gastrointestinal tract of patients in these two groups were compared. Results: No postoperative 30-day mortality was observed in all of the patients. The average total operation time of patients in the experimental group was (319±76) min, significantly longer than (233±76) min of the control group (P<0.001). The average aspartate transaminase (AST) level of patients in the experimental group at postoperative day 1 was 562.5 U/L, significantly higher than 347.0 U/L of control group (P=0.031). However, the average prothrombin activity levels of patients in the experimental group at postoperative day 3 and day 7 were (68.3±17.9)% and (73.4±10.2)%, respectively, significantly lower than (78.9±15.9)% and (80.0±10.6)% of control group (both P<0.05). There were no significant differences of tumor volume, differentiation degree, satellite lesion, dorsal membrane invasion, microvascular invasion between these two groups (all P>0.05). There were no significant differences of hospital stay, ventilation time, the incidence of hepatic insufficiency, ascites, pleural effusion, infection, biliary fistula between these two groups (all P>0.05). There were no significant differences of alanine aminotransferase (ALT), albumin, total bilirubin between these two groups at postoperative day 1, 3, 5 and 7 (all of P>0.05). Conclusion: The resection of centrally located HCC combined with intra-operative radiotherapy may increase the total operation time, delay the early postoperative recovery of liver function, but it is still safe and feasible. Trial registration: National Cancer Centre /Cancer Hospital, Chinese Academy of Medical Sciences, ChiCTR-TRC-12002802.
Subject(s)
Carcinoma, Hepatocellular/radiotherapy , Carcinoma, Hepatocellular/surgery , Intraoperative Care , Liver Neoplasms/radiotherapy , Liver Neoplasms/surgery , Alanine Transaminase/blood , Ascites/epidemiology , Bilirubin/blood , Blood Loss, Surgical , Carcinoma, Hepatocellular/pathology , Hepatectomy , Humans , Incidence , Length of Stay , Liver Neoplasms/pathology , Operative Time , Pilot Projects , Prospective StudiesABSTRACT
Objective: To analyze the clinicopathological features and prognosis of patients with small hepatocellular carcinoma. Methods: The clinicopathological and follow-up data of 98 patients with small hepatocellular carcinoma who underwent R0 resection from January 2009 to December 2013 were analyzed retrospectively. Results: All of the patients were followed up. Their postoperative 1-year, 3-year and 5-year overall survival rates were 99.0%, 91.7%, and 76.3%, respectively. Their postoperative median overall survival (OS) period was 52 months. The postoperative progression-free survival rates were 86.7%, 66.2% and 55.0%, respectively, and the median progression-free survival (PFS) period was 43.5 months. The univariate analysis showed that satellite nodules, liver capsule invasion and postoperative recurrence time were associated with OS (P<0.05), and long-term heavy drinking, satellite nodules and liver capsule invasion with PFS (P<0.05). The multivariate analysis indicated that long-term heavy drinking was an independent factor influencing the progression-free survival period of patients with small hepatocellular carcinoma (P=0.003) and postoperative recurrence time and liver capsule invasion were independent factors affecting their overall survival period (P<0.05). Conclusions: The treatment of small hepatocellular carcinoma still concentrates on the active treatment of surgery. It is beneficial to patients to minimize the resection scope of normal liver under the premise of R0 removal of tumor. Postoperative recurrence time of ≤2 years suggests poor prognosis of small hepatocellular carcinoma. Long-term heavy drinking can accelerate the recurrence of small hepatocellular carcinoma.
Subject(s)
Carcinoma, Hepatocellular/surgery , Liver Neoplasms/surgery , Aged , Alcohol Drinking/adverse effects , Analysis of Variance , Carcinoma, Hepatocellular/mortality , Disease-Free Survival , Female , Humans , Liver/pathology , Liver/surgery , Liver Neoplasms/mortality , Male , Middle Aged , Neoplasm Invasiveness , Neoplasm Recurrence, Local , Postoperative Period , Prognosis , Retrospective Studies , Survival Rate , Time FactorsABSTRACT
Endophytes from Cephalotaxus hainanensis Li, an important source of anti-leukemia drugs, have not been widely explored. In this study, 265 endophytic fungal isolates from C. hainanensis Li were screened for antimicrobial activities against tilapia, banana, rice, and rape and for antitumor activities against human leukemia cell lines (K562, NB4, and HL-60). Diversity was also analyzed. The results showed that 17.7% of the endophytic fungi had antimicrobial activities against at least three different test microbes, and activity against Fusarium oxysporum RKY102 was the highest at 15.8%. Cytotoxicity against at least one tumor cell line tested was observed in 18.5% of the endophytic fungi; with the highest value of 10.6% against K562. The endophytic fungal strains also showed relatively high activities against K562, NB4, and HL-60 while relatively fewer strains were cytotoxic against the human hepatic Hep-G2 and colon LoVo cancer cell lines. Thirty endophytic fungal strains showed both high antimicrobial and antitumor activities. Moreover, the analyses of the diversity of the 30 highly active strains showed they belonged to 20 species from 14 genera, and this is the first report of endophytic fungi Albonectria rigidiuscula, Colletotrichum magnisporum, and Nemania diffusa being isolated from Cephalotaxus plants. These findings suggest that natural antibacterial products for humans and tilapia; antifungal compounds for rice, rape, and banana; and antitumor compounds for leukemia therapy could be isolated from fungal strains derived from C. hainanensis Li.
Subject(s)
Cephalotaxus/microbiology , Colletotrichum , Endophytes , Fusarium , Anti-Infective Agents , Antineoplastic Agents , Biological Products/chemistry , Biological Products/pharmacology , Cell Line, Tumor , HL-60 Cells , Hep G2 Cells , Humans , K562 Cells , Medicine, Chinese Traditional , Microbial Sensitivity Tests , Plant Leaves/microbiologyABSTRACT
Salmonella have been demonstrated to inhibit tumor growth. However, the mechanism of Salmonella-induced tumor cell death is less defined. Autophagy is a cellular process that mediates the degradation of long-lived proteins and unwanted organelles in the cytosol. Tumor cells frequently display lower levels of basal autophagic activity than their normal counterparts and fail to increase autophagic activity in response to stresses. Autophagy is involved in the cell defense elimination of bacteria. The signaling pathways leading to activation of Salmonella-induced autophagy in tumor cells remain to be elucidated. We used autophagy inhibitor (3-Methyladenine) and apoptosis inhibitor (Z-VAD-FMK) to demonstrate that Salmonella may induce cell death via apoptosis and autophagic pathway. Meanwhile, we suggested that Salmonella induce autophagy in a dose- and time-dependent manner. The autophagic markers were increased after tumor cell infected with Salmonella. In addition, the protein express levels of phosph-protein kinase B (P-AKT), phosph-mammalian targets of rapamycin (P-mTOR), phosph-p70 ribosomal s6 kinase (P-p70s6K) in tumor cells were decreased by western analysis after Salmonella infection. In conclusion, our results point out that Salmonella induce the autophagic signaling pathway via downregulation of AKT/mTOR pathway. Herein, our findings that Salmonella in controlling tumor growth may induce autophagic signal pathway.
Subject(s)
Apoptosis , Autophagy , Biological Therapy , Melanoma/therapy , Salmonella enterica/pathogenicity , Animals , Melanoma/metabolism , Melanoma/microbiology , Mice , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Ribosomal Protein S6 Kinases, 70-kDa/genetics , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolismABSTRACT
We report new limits on a spin-independent weakly interacting massive particle (WIMP)-nucleon interaction cross section using 39.5 kg days of data taken with a p-type point-contact germanium detector of 840 g fiducial mass at the Kuo-Sheng Reactor Neutrino Laboratory. Crucial to this study is the understanding of the selection procedures and, in particular, the bulk-surface events differentiation at the sub-keV range. The signal-retaining and background-rejecting efficiencies were measured with calibration gamma sources and a novel n-type point-contact germanium detector. Part of the parameter space in the cross section versus WIMP-mass implied by various experiments is probed and excluded.
ABSTRACT
We present optitrode, a miniaturized flexible probe for integrated, localized light delivery and electrical recording. This device features an annular light guide with transparent polymer and fused silica layers surrounding a twisted-wire tetrode. We have developed a novel fabrication process, V-groove guided capillary assembly, to achieve high-precision, coaxial alignment of the various layers of the device. Optitrode with a length-to-diameter ratio â¼500 (5 cm long, 100 µm diameter) has been fabricated, and both the electrical and optical functions have been characterized. The prototype can deliver 11% (110 mW) of the total laser power under abrupt bending angle â¼25°.
Subject(s)
Electricity , Light , Optical DevicesABSTRACT
We report on a tunable intracavity optical parametric oscillator (IOPO) achieved using a two-dimensional (2D) periodically poled lithium niobate (PPLN) as simultaneously an electro-optic (EO) Bragg Q-switch and an optical frequency mixer (OFM) in a diode-pumped Nd:YVO(4) laser. The 2D periodic domain inversion structure is designed to provide two orthogonal reciprocal vectors to respectively satisfy the phase-matching conditions required by the two quasi-phase-matching devices (i.e., the PPLN EO Bragg deflector and the PPLN OFM). At a ~140-V Q-switching voltage and a 1-kHz switching rate, we obtained a signal wave at 1550 nm with a pulse energy of 9.7 µJ (corresponding to a peak power of ~2.4 kW) from the IOPO at 9.1-W diode pump power. Simultaneously we also observed multi-wavelength generation from the system originating in the single-pass parametric conversions in the 2D nonlinear photonic crystal structure. Temperature tuning of the IOPO signal wavelength in the eye-safe region was also demonstrated.
Subject(s)
Lasers, Solid-State , Lasers , Niobium/chemistry , Oscillometry/instrumentation , Oxides/chemistry , Signal Processing, Computer-Assisted/instrumentation , Equipment Design , Equipment Failure AnalysisABSTRACT
We report a mid-infrared, CW singly resonant optical parametric oscillator (OPO) with a thermally induced waveguide in its gain crystal. We measured a numerical aperture of 0.0062 for the waveguide at 80-W intracavity power at 3.2 microm. This thermal-guiding effect benefits to the stable operation of an OPO and improves the parametric conversion efficiency by more than a factor of two when compared with that without thermal guiding.
Subject(s)
Amplifiers, Electronic , Oscillometry/instrumentation , Refractometry/instrumentation , Transducers , Equipment Design , Equipment Failure Analysis , TemperatureABSTRACT
We report a CW, watt-level, red, green, and blue (RGB) laser pumped by an economical multimode (1-nm linewidth) Yb-fiber laser at 1.064 mum. A singly resonant optical parametric oscillator at 1.56 mum has two intracavity sum-frequency generators for red and blue laser generation. An extracavity second harmonic generator converts the residual pump power into green laser radiation. At 25-W pump power, the laser generated 3.9, 0.456, and 0.49 W at 633, 532, and 450 nm, respectively. The multimode pump laser offers a large temperature bandwidth for operating the RGB OPO without the need of a precision crystal temperature stabilizer.
ABSTRACT
OBJECTIVE: The aim of this study was to investigate the correlations of UDP glucuronosyltransferase family 1 member A1 (UGT1A1) gene polymorphisms with the onset and prognosis of non-small cell lung cancer. PATIENTS AND METHODS: A total of 400 patients with non-small cell lung cancer (disease group) and healthy controls (control group) in our hospital were selected as research subjects. Genomic DNA was extracted from the peripheral blood. UGT1A1 gene polymorphisms rs8330, rs4148323 and rs35003977 were detected after Polymerase Chain Reaction (PCR) amplification. RT-qPCR was performed to measure the expression level of UGT1A1. The survival of patients was analyzed combined with their prognosis. Moreover, the expression of UGT1A1 gene in lung cancer patients from The Cancer Genome Atlas (TCGA) database was analyzed by bioinformatics, and the prognosis was analyzed. RESULTS: According to the expression level of UGT1A1 gene from TCGA and GTEx databases, UGT1A1 gene was highly expressed in lung cancer tissues but lowly expressed in normal lung tissues, and the difference was statistically significant (p<0.05). Combined with the expression level of UGT1A1 and the prognostic information of lung cancer patients from TCGA database, patients with higher expression level of UGT1A1 gene exhibited significantly better prognosis than those with lower level (p=0.0013), suggesting that UGT1A1 gene is an anti-oncogene. There were statistically differences in allele distribution of UGT1A1 gene polymorphism rs8330 between the disease group and control group (p=0.003), and the frequency of allele G was higher in disease group. Moreover, the distribution of genotypes of UGT1A1 gene polymorphisms rs8330 (p=0.006) and rs4148323 (p=0.003) in the disease group was significantly different from that in the control group, and the frequencies of GG genotype of polymorphisms rs8330 and rs4148323 were higher in the disease group. Statistically significant differences in the distribution of recessive models of UGT1A1 gene polymorphism rs8330 were observed between the disease group and control group (p=0.047), and the disease group exhibited a lower frequency of recessive model GC + CC than control group. There were evident differences in the distribution of haplotype GGT of UGT1A1 gene polymorphisms rs8330, rs4148323 and rs35003977 between the disease group and control group (p=0.004), and the frequencies of haplotype GGT were higher in the disease group than those in the control group. UGT1A1 gene polymorphism rs8330 was remarkably associated with gene expression (p<0.05). Meanwhile, the expression of UGT1A1 gene in patients carrying genotype CC declined notably compared with that in patients carrying genotypes GG and GC (p<0.05). Furthermore, the polymorphism rs8330 had a significant correlation with the survival of patients in disease group (p=0.0001), and patients with genotype CC had the worst prognosis. CONCLUSIONS: UGT1A1 gene polymorphisms are prominently correlated with the onset and prognosis of non-small cell lung cancer.
Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Glucuronosyltransferase/genetics , Lung Neoplasms/genetics , Aged , Carcinoma, Non-Small-Cell Lung/mortality , Female , Genotype , Humans , Lung Neoplasms/mortality , Male , Middle Aged , Polymorphism, Genetic , PrognosisABSTRACT
In this study, the inelastic neutron scattering probe of SIKA in ANSTO is employed to investigate the magnon dispersion curve in ferromagnetic SrRuO3 single crystal epitaxial films and to better understand the underlying mechanisms. This report presents the successful measurement of a magnon peak from the SrRuO3 films which contained an amount of material of only 0.9 mg. We reveal one significant magnon dispersion curve along [002] following the quadratic E â Q 2 ) relation, which shows a magnon gap of 0.32 meV. We have discussed several possible mechanisms, such as the higher symmetry structure and the impurity levels, which may contribute to this smaller gap.
ABSTRACT
Human papillomavirus type 16 E5 (HPV-16 E5) is a highly hydrophobic membrane protein with weak-transforming activity, which is associated with ErbB4 receptor in HPV-16-infected cervical lesions. Presently, we investigated the transforming mechanisms of E5 involving ErbB4 signaling. Firstly, we report a role for ErbB4 (JM-b/CYT-1) receptor that activates c-jun gene expression and phosphorylating at Ser63 and Ser73 of the c-Jun protein in ligand-independent and Ras-c-jun NH(2)-terminal kinase-dependent pathway. Secondly, we show that HPV-16 E5 protein can form a complex with ErbB4 via binding to the extracellular and transmembrane domains of ErbB4 (JM-b/CYT-1). When co-expressing HPV-16 E5 and ErbB4 in cells, E5 can abrogate ErbB4-induced c-Jun protein expression and phosphorylation resulted in increasing cell proliferation compared to ErbB4-expressing cells. The interaction between of HPV-16 E5 and ErbB4 provides more insight into the mechanisms of HPV-16 E5 transformation induction.