Research on thermal-hydraulic behavior in the spent fuel pool using a full-height experimental facility

During accident scenarios the effective cooling of spent fuel directly affects the safety of nuclear power plants. Two experiments were performed in a full-height facility to study the thermal-hydraulic behavior in spent fuel pool. In spent fuel pool boiling experiment, the heat transfer characteristics are related to the flow patterns. However, the flow pattern in narrow and long channel is different from the traditional flow pattern. In the semi-dry of heated rod, wall temperature oscillation occurs for a long time. In the spent fuel pray experiment, the liquid film thickness varies randomly with time and space. As the spray flow density increase, the maximum wall temperature decrease gradually with a certain linear characteristic.

Spermatogenesis-associated 48 is essential for spermatogenesis in mice

Azoospermia, oligospermia and teratozoospermia all seriously impact male reproductive health. Spermatogenesis is a complex and precisely regulated process in which germ cells proliferate and differentiate and involves the regulation of multiple testis-specific genes. Here, we identified testis-specific gene spermatogenesis-associated 48 (SPATA48), the expression of which was age-dependent, indicating that it is involved in spermatogenesis. In humans and mice with azoospermia, expression of SPATA48 disappeared in the testis. Spata48-/- knockout male mice had smaller testis and defective spermatogenesis compared to wild-type (WT) mice. This study can help in the exploration of the genetic basis of male infertility and identify new targets for the diagnosis and treatment of male infertility.

Genetic polymorphism in cytochrome P450 2E1 and alcoholic pancreatitis sus-ceptibility: a meta-analysis

BACKGROUND

The association between cytochrome P450 2E1 (CYP2E1) polymorphism and the risk of alcoholic pancreatitis is contentious. This meta-analysis aimed to demonstrate the association between CYP2E1 RsaI/PstI, or DraI polymorphisms and the susceptibility of alcoholic pancreatitis.

MATERIALS AND METHODS

We searched for sources and background in Pubmed, Medline, Web of science and CNKI (Chinese national knowledge infrastructure), using the following keywords: "cytochrome P450 2E1" or "CYP2E1", "polymorphism" or "genotype", in combination with "alcoholic pancreatitis". All meta-analyses were performed with Stata 12.0. Subgroup analyses on ethnicity and type of alcoholic pancreatitis were conducted as well.   Results: Eleven articles, which met the inclusion criteria, included 595 patients with alcoholic pancreatitis, and 1767 controls. For the general population, our analysis suggested no obvious association between CYP2E1 RsaI/PstI or DraI polymorphisms and the risk of alcoholic pancreatitis. However, in the non-Asian subgroup, significant associations were found between the risk for alcoholic pancreatitis and CYP2E1 RsaI/PstI polymorphism [dominant model: odds ratio (OR) =1.92, 95 % confidence interval (CI): 1.25-2.95, p =0.003; allelic contrast model: OR =1.99, 95 % CI: 1.35-2.92, p <0.001. There was not a significant association found within the Asian group. Meanwhile, the susceptibilities of chronic alcoholic pancreatitis were significantly increased for dominant and allelic contrast models of CYP2E1 RsaI/PstI polymorphism [OR =1.62, 95 % CI: 1.12-2.34; p =0.011; OR =1.62, 95 % CI: 1.17-2.24, p = 0.004, respectively] but not for acute alcoholic pancreatitis for all population.

CONCLUSIONS

CYP2E1 RsaI/PstI polymorphism may increase the risk of alcoholic pancreatitis in the non-Asian population. Additionally, the CYP2E1 RsaI/PstI polymorphism may increase the susceptibility for chronic alcoholic pancreatitis for all population. HIPPOKRATIA 2018, 22(2): 60-67.

Spatial Distortion of Vibration Modes via Magnetic Correlation of Impurities

Long wavelength vibrational modes in the ferromagnetic semiconductor Ga_{0.91}Mn_{0.09}As are investigated using time resolved x-ray diffraction. At room temperature, we measure oscillations in the x-ray diffraction intensity corresponding to coherent vibrational modes with well-defined wavelengths. When the correlation of magnetic impurities sets in, we observe the transition of the lattice into a disordered state that does not support coherent modes at large wavelengths. Our measurements point toward a magnetically induced broadening of long wavelength vibrational modes in momentum space and their quasilocalization in the real space. More specifically, long wavelength vibrational modes cannot be assigned to a single wavelength but rather should be represented as a superposition of plane waves with different wavelengths. Our findings have strong implications for the phonon-related processes, especially carrier-phonon and phonon-phonon scattering, which govern the electrical conductivity and thermal management of semiconductor-based devices.

Intravoxel Incoherent Motion MR Imaging in the Differentiation of Benign and Malignant Sinonasal Lesions: Comparison with Conventional Diffusion-Weighted MR Imaging

BACKGROUND AND PURPOSE

Intravoxel incoherent motion is a promising method for the differentiation of sinonasal lesions. This study aimed to evaluate the value of intravoxel incoherent motion in the differentiation of benign and malignant sinonasal lesions and to compare the diagnostic performance of intravoxel incoherent motion with that of conventional DWI.

MATERIALS AND METHODS

One hundred thirty-one patients with histologically proved solid sinonasal lesions (56 benign and 75 malignant) who underwent conventional DWI and intravoxel incoherent motion were recruited in this study. The diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) values derived from intravoxel incoherent motion and ADC values derived from conventional DWI were measured and compared between the 2 groups using the Student t test. Receiver operating characteristic curve analysis, logistic regression analysis, and 10-fold cross-validation were performed to evaluate the diagnostic performance of single-parametric and multiparametric models.

RESULTS

The mean ADC and D values were significantly lower in malignant sinonasal lesions than in benign sinonasal lesions (both P < .001). The mean f value was higher in malignant lesions than in benign lesions (P = .003). Multiparametric models can significantly improve the cross-validated areas under the curve for the differentiation of sinonasal lesions compared with single-parametric models (all corrected P < .05 except the D value). The model of D+f provided a better diagnostic performance than the ADC value (corrected P < .001).

CONCLUSIONS

Intravoxel incoherent motion appears to be a more effective MR imaging technique than conventional DWI in the differentiation of benign and malignant sinonasal lesions.

Mechanochemical synthesis of high coercivity Nd2(Fe,Co)14B magnetic particles

With increasing demand for magnets in energy conversion systems, the quest for the development and understanding of novel processing routes to produce permanent magnets has become urgent. We report a novel mechanochemical process for the synthesis of Nd₂(Fe,Co)₁₄B magnetic particles with a high coercivity of 12.4 kOe. This process involves the reduction of neodymium oxide, iron oxide, cobalt oxide and boron anhydride in the presence of a calcium reducing agent and a CaO diluent. The formation mechanism of Nd₂(Fe,Co)₁₄B changed with increasing CaO content, and the average crystal size of the Nd₂(Fe,Co)₁₄B particles also increased, resulting in an increase in the coercivity values. The reaction mechanism during milling was revealed through a study of the phase transformations as a function of milling time. It was found that unlike self-propagating reactions, this reduction reaction during milling requires continuous input of mechanical energy to reach a steady state.

High energy product chemically synthesized exchange coupled Nd2Fe14B/α-Fe magnetic powders

The excellent hard magnetic properties of Nd₂Fe₁₄B based magnets have an enormous range of technological applications. Exchange-coupled Nd₂Fe₁₄B/α-Fe magnets were chemically synthesized by a microwave assisted combustion process to produce mixed oxides, followed by a reduction diffusion process to form magnetic nano-composite powder. This synthesis technique offers an inexpensive and facile platform to produce exchange coupled hard magnets. The size dependent magnetic properties were investigated. The formation mechanisms of the oxide powders and the reduction diffusion mechanism were identified. The microwave power was found to play a crucial role in determining the crystallite size. The coercivity of the powder increased with increasing particle size. Room temperature coercivity (H_c) values greater than 9 kOe and magnetization of 110 emu g^-1 was obtained in particles with a mean size of ∼62 nm. An energy product of 5.2 MGOe was obtained, which is the highest reported value for chemically synthesized hard magnetic Nd₂Fe₁₄B/α-Fe powders.

[The altered topology of brain structural network in patients with acute stress response after traffic accident]

Objective: To explore the changes of brain activities in traffic accident survivors with acute stress response (ASR) within a week by using complex networks analysis method based on graph-theory, and to find out the alteration of topological properties in structural brain network. Method: From January, 2013 to February, 2016, twenty traffic accidents survivors with acute stress disorders (Acute Stress Disorder Interview, ASDI>3)and twenty healthy controls underwent the 3T diffusion tensor imaging (DTI) magnetic resonance imaging scan in Nanjing General Hospital.The graph-theory analysis method was used to compare the structural brain network properties and nodal features between ASR survivors and controls.Statistical analyses were also performed by including anxiety and depression as covariates to evaluate their effect.In additional, Pearson correlation was performed between abnormal parametric values and clinical indices. Results: (1) The brain structural networks had small-world properties in both groups; (2) while compared with healthy controls, patients with ASR showed increased weighted connectivity strength (Si, 1.36±0.47 vs 0.92±0.38, P=0.008) and nodal betweenness centrality (BCi, 20±15 vs 7±6, P=0.002) in left triangular part of inferior frontal (IFG triang_L), increased Si in orbital part of inferior frontal gyrus (1.10±0.31 vs 0.77±0.30, P=0.004) and obviously decreased Si in left caudate (0.75±0.24 vs 1.04±0.35, P=0.004); (3) furthermore, the inclusion of anxiety and depression as covariates abolished nodal parameters differences in IFG triang_L, left caudate, thalamus and inferior temporal gyrus. Conclusions: The brain structure network in ASR patients has small world properties.But nodal parameters change obviously in some nodes compared with healthy controls and mainly locate in prefrontal lobe and striatum. High levels of anxiety and depression in ASR patients may partly account for these alterations.

Tyrosine phosphorylation of Kv1.5 is upregulated in intrauterine growth retardation rats with exaggerated pulmonary hypertension

Intrauterine growth retardation (IUGR) is associated with the development of adult-onset diseases, including pulmonary hypertension. However, the underlying mechanism of the early nutritional insult that results in pulmonary vascular dysfunction later in life is not fully understood. Here, we investigated the role of tyrosine phosphorylation of voltage-gated potassium channel 1.5 (Kv1.5) in this prenatal event that results in exaggerated adult vascular dysfunction. A rat model of chronic hypoxia (2 weeks of hypoxia at 12 weeks old) following IUGR was used to investigate the physiological and structural effect of intrauterine malnutrition on the pulmonary artery by evaluating pulmonary artery systolic pressure and vascular diameter in male rats. Kv1.5 expression and tyrosine phosphorylation in pulmonary artery smooth muscle cells (PASMCs) were determined. We found that IUGR increased mean pulmonary artery pressure and resulted in thicker pulmonary artery smooth muscle layer in 14-week-old rats after 2 weeks of hypoxia, while no difference was observed in normoxia groups. In the PASMCs of IUGR-hypoxia rats, Kv1.5 mRNA and protein expression decreased while that of tyrosine-phosphorylated Kv1.5 significantly increased. These results demonstrate that IUGR leads to exaggerated chronic hypoxia pulmonary arterial hypertension (CH-PAH) in association with decreased Kv1.5 expression in PASMCs. This phenomenon may be mediated by increased tyrosine phosphorylation of Kv1.5 in PASMCs and it provides new insight into the prevention and treatment of IUGR-related CH-PAH.

KCTD12 promotes tumorigenesis by facilitating CDC25B/CDK1/Aurora A-dependent G2/M transition

Cell cycle dysregulation leads to uncontrolled cell proliferation and tumorigenesis. Understanding the molecular mechanisms underlying cell cycle progression can provide clues leading to the identification of key proteins involved in cancer development. In this study, we performed proteomics analysis to identify novel regulators of the cell cycle. We found that potassium channel tetramerization domain containing 12 (KCTD12) was significantly upregulated in M phase compared with S phase. We also found that KCTD12 overexpression not only facilitated the G2/M transition and induced cancer cell proliferation, but also promoted the growth of subcutaneous tumors and Ki-67 proliferation index in mice. Regarding the mechanism underlying these phenomena, cyclin-dependent kinase 1 (CDK1) was identified as an interacting partner of KCTD12 by immunoprecipitation and mass spectrometry analysis, which showed that KCTD12 activated CDK1 and Aurora kinase A (Aurora A) and that the effects of KCTD12 on CDK1 phosphorylation and cell proliferation were abrogated by cell division cycle 25B (CDC25B) silencing. In addition, Aurora A phosphorylated KCTD12 at serine 243, thereby initiating a positive feedback loop necessary for KCTD12 to exert its cancer-promoting effects. Furthermore, we analyzed the expression levels of various genes and the correlations between the expression of these genes and survival using tumor tissue microarray and Gene Expression Omnibus (GEO) data sets. The data showed that KCTD12 expression was significantly upregulated in cervical and lung cancers. More importantly, high KCTD12 expression was associated with larger tumor sizes, higher pathological stages and poor patient survival. Collectively, our study demonstrate that KCTD12 binds to CDC25B and activates CDK1 and Aurora A to facilitate the G2/M transition and promote tumorigenesis and that Aurora A phosphorylates KCTD12 at serine 243 to trigger a positive feedback loop, thereby potentiating the effects of KCTD12. Thus, the KCTD12-CDC25B-CDK1-Aurora A axis has important implications for cancer diagnoses and prognoses.

Time zero determination for FEL pump-probe studies based on ultrafast melting of bismuth

A common challenge for pump-probe studies of structural dynamics at X-ray free-electron lasers (XFELs) is the determination of time zero (T₀)-the time an optical pulse (e.g., an optical laser) arrives coincidently with the probe pulse (e.g., a XFEL pulse) at the sample position. In some cases, T₀ might be extracted from the structural dynamics of the sample's observed response itself, but generally, an independent robust method is required or would be superior to the inferred determination of T₀. In this paper, we present how the structural dynamics in ultrafast melting of bismuth can be exploited for a quickly performed, reliable and accurate determination of T₀ with a precision below 20 fs and an overall experimental accuracy of 50 fs to 150 fs (estimated). Our approach is potentially useful and applicable for fixed-target XFEL experiments, such as serial femtosecond crystallography, utilizing an optical pump pulse in the ultraviolet to near infrared spectral range and a pixelated 2D photon detector for recording crystallographic diffraction patterns in transmission geometry. In comparison to many other suitable approaches, our method is fairly independent of the pumping wavelength (UV-IR) as well as of the X-ray energy and offers a favorable signal contrast. The technique is exploitable not only for the determination of temporal characteristics of the experiment at the interaction point but also for investigating important conditions affecting experimental control such as spatial overlap and beam spot sizes.

Oral Chinese herbal medicine as maintenance treatment after chemotherapy for advanced non-small-cell lung cancer: a systematic review and meta-analysis

BACKGROUND

The concept of maintenance therapy in cancer treatment is currently under debate because of modest survival benefits, added toxicity, economic considerations, and quality-of-life concerns. Traditional Chinese Medicine (tcm) is widely used in China for cancer patients, offering the advantages of low toxicity and enhancement of quality of life. However, no systematic reviews or meta-analyses have assessed the role of tcm as maintenance treatment for non-small-cell lung carcinoma.

METHODS

We searched the Chinese Biomedical Literature Database, the China National Knowledge Infrastructure, PubMed, embase, and the Cochrane Library databases for all eligible studies. The endpoints were overall survival (os), progression-free survival (pfs), the 1-year and 2-year survival rates, and performance status. Our meta-analysis used a fixed-effects model and a random-effects model for heterogeneity in the Stata software application (version 11.0: StataCorp LP, College Station, TX, U.S.A.), with the results expressed as hazard ratios (hrs) or risk ratios (rrs), with their corresponding 95% confidence intervals (95% cis).

RESULTS

Sixteen randomized studies representing 1150 patients met the inclusion criteria. Compared with best supportive care, observation, or placebo, tcm as maintenance treatment was associated with a significant increase in os (hr: 0.49; 95% ci: 0.35 to 0.68; p < 0.001), pfs (hr: 0.66; 95% ci: 0.51 to 0.84; p = 0.001), and 2-year survival rate (rr: 0.63; 95% ci: 0.44 to 0.92, p = 0.017), and a significant improvement in performance status (rr: 0.68; 95% ci: 0.61 to 0.75; p < 0.001).

CONCLUSIONS

For patients who show non-progression-including stable disease, partial response, or complete response-after first-line chemotherapy, including those with poor quality of life, oral Chinese herbal medicine can be considered an efficient and safe maintenance therapy strategy.

Hot carrier relaxation in CdTe via phonon-plasmon modes

Carrier and lattice dynamics of laser excited CdTe was studied by time-resolved reflectivity for excitation fluences spanning about three orders of magnitude, from 0.064 to 6.14 mJ cm^-2. At fluences below 1 mJ cm^-2 the transient reflectivity is dominated by the dynamics of hybrid phonon-plasmon modes. At fluences above 1 mJ cm^-2 the time-dependent reflectivity curves show a complex interplay between band-gap renormalization, band filling, carrier dynamics and recombination. A framework that accounts for such complex dynamics is presented and used to model the time-dependent reflectivity data. This model suggests that the excess energy of the laser-excited hot carriers is reduced much more efficiently by emitting hybrid phonon-plasmon modes rather than bare longitudinal optical phonons.

Abstract P5-02-05: Biology and long-term prognosis of screening detected non-palpable breast cancer by ultrasound in hospital-based Chinese population (2001-2014)

Background: Milestone studies showed that ultrasound (US) was an effective primary screening test for breast cancer both in the western world and in China [PMID: 26712110, 26715161, and 25668012]. Ultrasound has been officially designated to be the initial imaging test for breast cancer screening in Beijing and several other cities in China, due to its improved sensitivity in Chinese women who usually have denser breasts and develop breast cancer earlier than Caucasian counterparts. Study showed that it would take 40 years to screen each woman in the target age group once [PMID: 26808342].The mainstay modality of breast cancer screening in China is the hospital-based opportunistic screening among asymptomatic self-referred women. However, there is little data about the tumor biology and long-term survival of the US-detected non-palpable breast cancer (NPBC) in hospital-based Chinese population.

Methods: From January 2001 to December 2014, 3,786 asymptomatic women with positive (BI-RADS 4 and 5) initial screening US underwent biopsies in Peking Union Medical College Hospital, and 572 NPBC in 556 women were diagnosed. Women without dense breasts (defined as BI-RADS category C and D) also received screening mammography (MG) after physical examination and ultrasound. 788 patients with positive (BI-RADS 4 and 5) mammogram (MG) and normal US (BI-RADS 1, 2 and 3) underwent MG-guided biopsies and another 127 NPBC were diagnosed in 126 women. The clinicopathological features, treatment choice, 10-year disease-free survival (DFS) and overall survival (OS) were reviewed and compared between the US-detected and MG-detected NPBC. Prognostic factors of NPBC were identified.

Results: Overall, US could detect more invasive NPBC (83.4% vs 54.3%, p&lt;0.001), lymph node positive cancer (19.1% vs 10.2%, p&lt;0.001)and multifocal cancer (19.2% vs 6.3%, p&lt;0.001). In invasive NPBC, US detected more low grade cancer (21.4% vs 10.2%, p=0.001), multifocal cancer (20.7% vs 2.9%, p&lt;0.001), Her2 negative cancer (77.6% vs 62.3%, p=0.001) and larger tumor (pT1c+pT2, 53.3% vs 37.6%, p&lt;0.001). There was no significant difference in immunophenotype/subtype, treatment methods, DFS or OS between US- and MG-NPBC among ductal carcinoma in situ (DCIS), invasive and all NPBC. For all NPBC and the US-NPBC, the common DFS-factors included pT, pN and p53 whereas OS-predictors were pN and immunophenotype/subtype.

Table 1. Kaplan-Meier estimates of DFS and OS between US-NPBC and MG-NPBC§.Patients (No.)10-year DFS (%)P value10-year OS (%)P valueAllUS-NPBC (572)90.60.73896.10.142 MG-NPBC (127)92.7 100.0 DCISUS-NPBC (94)100.00.060100.0- MG-NPBC (58)93.8 100.0 InvasiveUS-NPBC (478)88.60.68095.20.239 MG-NPBC (69)92.0 100.0 § Kaplan-Meier survival curves between each two subgroups would be displayed in the poster.

Conclusion: Compared to MG, US detected more invasive NPBC with positive lymph node in hospital-based asymptomatic self-referred Chinese women, who could achieve comparable 10-year DFS and OS as MG-detected NPBC. US could serve as the feasible initial imaging modality in hospital-based opportunistic screening Chinese women.

Citation Format: Yao R, Pan B, Zhu Q, Xu Q, Zhou Y, Zhang J, Mao F, You S, Lin Y, Shi J, Guan J, Wang X, Zhang Y, Zhang X, Shen S, Zhong Y, Xu Y, Liang Z, Jiang Y, Sun Q. Biology and long-term prognosis of screening detected non-palpable breast cancer by ultrasound in hospital-based Chinese population (2001-2014) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-02-05.

Mid-wave infrared narrow bandwidth guided mode resonance notch filter

We have designed, fabricated, and characterized a guided mode resonance notch filter operating in the technologically vital mid-wave infrared (MWIR) region of the electromagnetic spectrum. The filter provides a bandstop at λ≈4.1  μm, with a 12 dB extinction on resonance. In addition, we demonstrate a high transmission background (>80%), less than 6% transmission on resonance, and an ultra-narrow bandwidth transmission notch (10  cm^-1). Our filter is optically characterized using angle- and polarization-dependent Fourier transform infrared spectroscopy, and simulated using rigorous coupled-wave analysis (RCWA) with excellent agreement between simulations and our experimental results. Using our RCWA simulations, we are able to identify the optical modes associated with the transmission dips of our filter. The presented structure offers a potential route toward narrow-band laser filters in the MWIR.