Exploring the sensitivity of α-decay half-life to neutron skin thickness for nuclei around ^(208)Pb

Based on the newest experimentally extracted nuclear density distributions for double-magic nucleus208Pb(Tarbert et al. in Phys Rev Lett 112:242502, 2014),the sensitivity of α-decay half-life to nuclear skin thickness is explored in the vicinity of the shell closure region around208 Pb, i.e., isotopes of Z ? 82 and isotones of N ? 126.With the two-parameter Fermi(2PF) density distributions and an analytically derived formula, the α-decay half-life is found to be closely related to the magnitude of nuclear skin thickness. For a decays to the Z ? 82 isotopes, the α-decay half-life is found to decrease with the increasing neutron skin thickness, while the opposite behavior is found for a decays to the N ? 126 isotones. Therefore, it could be a possible way to extract the nuclear skin thickness from measured α-decay half-lives.

Prostate-specific antigen half-life： a new predictor of progression- free survival and overall survival in Chinese prostate cancer patients

We investigated the potential value of prostate-specific antigen half-life （PSAHL） and decreasing velocity （PSAVd） to predict progression-free survival （PFS） and overall survival （OS） in Chinese patients with prostate cancer. A total of 153 patients treated with hormonal therapy were included in the study. Of these, 78 patients progressed to hormone- refractory prostate cancer （HRPC） and 24 patients died by the end of follow-up. PSAHL was defined as the time during which prostate-specific antigen （PSA） concentration became half of the initial value during the first hormonal therapy. PSAVd reflected the decreasing velocity of PSA during the first hormonal therapy. PFS was defined as the interval from the beginning of hormonal therapy to HRPC. Cox proportional hazards regression analysis was used to evaluate whether PSAHL and PSAVd were significantly associated with PFS and OS. The median PSAHL and PSAVd were 0.50 months and 33.8 ng mL^-1 per month. The median PFS and OS were 22.7 months （95% confidence interval [CI], 22.0-29.6 months） and 43.5 months （95% CI, 37.9-48.4 months）, respectively. On univariate and multivariate analysis, long PSAHL （〉 0.5 months）, metastatic disease, high biopsy Gleason scores （〉 8） and high nadir PSA （〉 0.4 ng mL^-1） were all found to be significantly associated with short PFS. Long PSAHL, high nadir PSA and short PSA doubling time （PSADT 〈 2.0 months） were significantly associated with short OS. There were no significant relationships between PSAVd and either PFS or OS. Thus, PSAHL is a promising new independent predictor of survival. Patients with long PSAHL were identified as those at high risk for a relatively short PFS and OS.

Antibody fragments: Prolonging circulation half-life special issue-antibody research

Antibodies are currently the fastest growing class of therapeutic proteins. When antibody fragments are included, there are over thirty-five antibody-based medicines approved for human therapy. Many more antibody and antibody-like fragments are being evaluated clinically. Production of antibody fragments can be efficient and their compact size can allows for better tissue extravasation into solid tumors than full antibodies. Unfortunately, a key limitation of antibody fragments for systemic use is their short half-life in circulation. Prolonging their circulation half-life can be accomplished clinically by the covalent conjugation of the antibody fragment to the water-soluble polymer, poly(ethylene glycol) (PEG). Many polymers and strategies are also being pursued to increase antibody fragment half-life.

Determinations of ^(171)Er half-life and some ^(171)Tm transition energies

The neutrons have been captured by Erbium nuclei which were received by using clinical electron linear accelerator. In this experiment, the possibility of the neutron capture process has been observed because of emitted neutrons appearing in the experimental area. In particular,neutron capture of ^(170)Er nucleus has been observed. After the neutron capture of ^(170)Er nucleus, the unstable ^(171)Er has been formed and decayed into the ^(171)Tm. By using this reaction path, some transition energies of ^(171)Tm obtained from the residual activity measurements and the half-life of ^(171)Er have been determined, and they are in agreement with adopted values in the literature.

Improved systemic half-life of glucagon-like peptide-1-loaded carbonate apatite nanoparticles in rats

BACKGROUND Glucagon-like peptide-1(GLP1)is an endogenous peptide that regulates blood glucose level.But its susceptibility to rapid metabolic degradation limits its therapeutic use.AIM To prepare GLP1-encapsulated nanosize particle with controlled release property to improve the systemic half-life of GLP1.METHODS GLP1 nanoparticles were prepared by complexation of GLP1 with carbonate apatite nanoparticles(CA NPs).The physicochemical properties of the CA NPs,the effects of GLP1-loaded CA NPs on cell viability,and the systemic bioavailability of GLP1 after CA NPs administration were determined.RESULTS The GLP1-loaded CA NPs was within 200 nm in size and stable in fetal bovine serum.The formulation did not affect the viability of human cell lines suggesting that the accumulation of CA NPs in target tissues is safe.In Sprague Dawley rats,the plasma GLP1 Levels as measured from the GLP1-loaded CA NPs-treated rats,were significantly higher than that of the control rats and free GLP1-treated rats at 1 h post-treatment(P<0.05),and the level remained higher than the other two groups for at least 4 h.CONCLUSION The GLP1-loaded CA NPs improved the plasma half-life of GLP1.The systemic bioavailability of GLP1 is longer than other GLP1 nanoparticles reported to date.

2-9 Half-life Measurement of 94mRu44+ at CSRe

A radioactive nucleus is characterized with an intrinsic half-life. However, for a nuclear species, the half-lives inneutral atoms could be very different from that in highly charged ions. The half-lives of some highly charged ionshave been directly measured at GSI for multiple motivations[1]. In the same case, the nuclear state(i:e the isomer)may be in the range of several tens of microseconds and their half-live can be measured using isochronous massspectrometry. The J = 8+ isomeric state in 94Ru was chosen to test this method. The half-life of this isomer is71 s [2] in neutral atoms, and the excitation energy is 2.64 MeV. The internal conversion coefficient of this decayin neutral atom is 0.335. So its half-life in the bare nucleus would be modified to be 94.78 s when the internalconversion channel is blocked.

VR技术在游戏设计中的交互与特征研究——以游戏《Half-Life:Alyx》为例

游戏不光需要在剧情、美术设计上表现出彩,在游戏的可操作性内容设计上也同样需要有吸引力。通过VR游戏《Half-Life:Alyx》的体验可以了解到有着丰富游戏制作经验的大厂对VR游戏中交互设计内容的选择与理解,也可以学习到大厂对于游戏剧情语言的把握。

Systematic Analysis of Post-Translational Modifications for Increased Longevity of Biotherapeutic Proteins

Protein-based therapeutics (PPTs) are drugs used to treat a variety of different conditions in the human body by alleviating enzymatic deficiencies, augmenting other proteins and drugs, modulating signal pathways, and more. However, many PPTs struggle from a short half-life due to degradation caused by irreversible protein aggregation in the bloodstream. Currently, the most researched strategies for improving the efficiency and longevity of PPTs are post-translational modifications (PTMs). The goal of our research was to determine which type of PTM increases longevity the most for each of three commonly-used therapeutic proteins by comparing the docking scores (DS) and binding free energies (BFE) from protein aggregation and reception simulations. DS and BFE values were used to create a quantitative index that outputs a relative number from −1 to 1 to show reduced performance, no change, or increased performance. Results showed that methylation was the most beneficial for insulin (p < 0.1) and human growth hormone (p < 0.0001), and both phosphorylation and methylation were somewhat optimal for erythropoietin (p < 0.1 and p < 0.0001, respectively). Acetylation consistently provided the worst benefits with the most negative indices, while methylation had the most positive indices throughout. However, PTM efficacy varied between PPTs, supporting previous studies regarding how each PTM can confer different benefits based on the unique structures of recipient proteins.

Simple Formula of β^+-Decay Half-Lives of Nuclei Far From β-Stable Line

We generalize the formula of β^+-decay half-lives [Phys.Rev.C 78 (2006) 014305] to include all availabledata of nuclei far from the β-stable line. Good agreement with experimental data is obtained by taking into accountthe even-odd (e-o) effect.It is shown that the e-o effect on β^+-deeay half-life is apparent for the allowed β^+-transition,whereas it is not apparent for the first and second forbidden transitions.This demonstrates that the allowed β^+-transitionis more sensitive to the nuclear even-odd effect than the forbidden β^+-transition.The underlying physics is discussed.This formula can be used to predict the β^+-decay half-lives of the nuclei far from β-stability.It is useful to experimentalphysicists for analyzing the data of β^+-decay.

Benford's Law and β-Decay Half-Lives

The experimental values of 2059 β-decay half-lives are systematically analyzed and investigated. We have found that they are in satisfactory agreement with Benford＇s law, which states that the frequency of occurrence of each figure, 1-9, as the first significant digit in a surprisingly large number of different data sets follows a logarithmic distribution favoring the smaller ones. Benford＇s logarithmic distribution of β-deeay half-lives can be explained in terms of Neweomb＇s justification of Benford＇s law and empirical exponential law of β-decay half-lives. Moreover, we test the calculated values of 6721 β-decay half-lives with the aid of Benford＇s law. This indicates that Benford＇s law is useful for theoretical physicists to test their methods for calculating β-decay half-lives.

Conservation Laws of Physics in Dirac Vacuum and β-Decay of Nuclei

The laws of conservation of energy, linear momentum. and angular momentum of a system form a closed unit according to Noether's theorem. A generalization of these laws (including spin) for elementary par- ticles taking into account the states of negative energies of the Dirac vacuum is given. A new interpretation of the β-decay of nuclei without neutrinos. using interactions with Dirac's anti-world is discussed, which ex- plains all characteristics of the β-continuum. A quantum-electrodynamic theory of β-decay is presented in which Fermi's constant g of weak interactions is determined from first principles (without neutrinos). The lat- ter is an expression of e, h, c, m, M, and R, i.e., g is not an independent constant of physics nor is it necessa- ry to measure it.

Study of the Alpha-Decay Chain for ^(194)Rn with Relativistic Mean-Field Theory

The structures of the nuclei on the alpha-decay chain of ^194Rn are investigated in the deformed relativistic mean-field theory with the effective interaction TMA. We put an emphasis on the ground state properties of ^194Rn. The calculated alpha-decay energies and lifetimes are both very close to the experimental data for ^186Pb and ^190Po. For ^194Rn, the deviations are a little large on both the alpha-decay energy and the lifetime. We also calculate the alpha-decay energies for the isotopes 192～208^Rn. The tendency for the change of the alpha-decay energies with neutron number is correctly reproduced in the relativistic mean-field theory （RMF）. In general, the RMF theory can give a good description of the alpha decay chain of ^194Rn.

β-Decay of Light Neutron-Rich Nuclei

The β-decays of neutron-rich carbon, nitrogen and fluorine isotopes have been systematically studied using the OXBASH shell Model. In the psd, spsd and spsdpf model space, we use the WBP interaction to calculate the half-lives and neutron emission probabilities of neutron- rich carbon and nitrogen isotopes, respectively. With the USD （W） and CW interactions, we calculate the half-lives and neutron emission probabilities of neutron-rich fluorine isotope in the sd model space, respectively. The calculated half-lives and neutron emission probabilities reproduce recent experimental data very well. It seems to show that the particles of the neutron-rich carbon and nitrogen isotopes are mainly excited in the spsd space. The β-decay of 21N to the neutron bound states in 210 is mostly the first forbidden transition which makes the neutron emission probability increase. The theoretical calculation of β-decay of 25F to 25Ne with CW interaction shows that CW interaction is better than USD interaction.

2-11 Stellar -decay Rate of 59Fe and Its Impact on the 60Fe Nucleosynthesis

60Fe is a long-lived nucleus (T1=2=2.62×106 a) which is mainly synthesized in the Carbon-shell burning ofmassive stars. It still could be observed nowadays after being ejected to the space after massive star ends its life assupernova. Along with another long-lived nucleus 26Al (T1=2=7.17×105 a) which is synthesized in the similar stars,the observation of their decay could provide the information of stellar evolution. From 2002-2005 the INTEGRALsatellite with detector obtained 60Fe/26Al flux ratio in our Galaxy to be 0.148(60)[1]. It's significantly smallerthan the theoretical prediction 0.45[2], and indicated that the theory need to be improved to increase the 60Fe yieldor decrease 26Al yield. 60Fe is produced by neutron capture reactions: 58Fe(n, )59Fe and 59Fe(n, )60Fe. Thecompetition between -decay of 59Fe and its neutron capture plays an important role in 60Fe synthesis path. In thepresent work, the impact on the 60Fe synthesis of the -decay process in stellar environment is studied.

The contribution of the first forbidden transitions to the nuclear β^--decay half-life

β-decay half-life is a key quantity for nuclear structure and nucleosynthesis studies.There exist large uncertainties in the contributions of allowed and forbidden transitions to the totalβ-decay life,which limits the resolution of the predictedβ-decay half-life.We systematically study the contribution of the first forbidden(FF)transitions to theβ--decay half-life,and quantify it with a formula based on simple physics considerations.We also propose a new formula for calculation of theβ--decay half-life that includes the FF contribution.It is shown that the inclusion of the contribution of FF transitions significantly improves the precision of calculations of theβ--decay half-life.By fitting of the RQRPA results for neutron-rich Z=47,57 isotopes and N=80,94 isotones,the formula for the contribution of the FF transitions gives similar results as the RQRPA calculations.However,because of limited experimental data for the branching ratios of unstable nuclei,the fit parameters are not fully constrained.Therefore,the proposed formula for theβ--decay half-life is more suitable for calculations of half-lives than of the FF contributions.The formula could be used to predict theβ?-decay half-life in nuclear structure studies as well as nucleosynthesis calculations in stars.

Relation Matrix of Water Exchange for Sea Bays and Its Application

Water exchange is an important hydrodynamic character of sea bays, and it is the basis for the study of the environmental capacity of sea bays. In this paper, a relation matrix is set up to describe the interaction among different areas of a sea bay, and to predict the water quality of those areas. The relation matrix is calculated based on the numerical results from a water quality model. This method is applied to the study of water exchange and the prediction of water quality of the Bohai Sea. The Bohai Sea is divided into five areas, and the effect of seasonal wind is taken into consideration. The results show a） the relation matrix can be used to study the water exchange among different areas and predict water quality of different areas at the respective characteristic time, b） the reduction of pollutant is dependent on both water exchange and initial distribution of the pollutant, and c） the half-life time of the pollutant is longer than the half-exchange time of the sea water.

3D-QSAR study on atmospheric half-lives of POPs using CoMFA and CoMSIA

3D-QSAR studies of persistent organic pollutants(POPs)screening for atmosphere persistence were performed by comparative molecular field analysis(CoMFA)and comparative molecular similarity index analysis(CoMSIA)methods.The mean and maximum half-life estimations for degradation in air of 49 UNEP POPs and possible POPs were modeled.Both groups’data have been modeled to obtain an average estimate and a predictive value for ranking and screening purposes.CoMFA and CoMSIA models have given cross-validation regre...

A Simulation Study on Effect of Surface Film-Forming Material on Water Evaporation

A greenhouse experiment was conducted to investigate the effect of surface film-forming material (SFFM), a mixture of 16-18-octadecanols by emulsification, on water evaporation. Air-dried soil with distilled water was incubated firstly for 7 days to reestablish soil biological activity and then for another 7 days after treated with SFFM at rates of 0, 1, 2, 4, 6 and 8 g m-2, respectively. Everyday during the 7-day incubation after addition of SFFM, water losses due to evaporation were ~measured by an electronic balance. The rate of water evaporation with the addition of SFFM was reduced significantly compared with the control treatment and the effectiveness of SFFM on water evaporation reduced with time. According to the equation expressions of the effect of SFFM on water evaporation, the half-life of electiveness of SFFM on water evaporation was introduced and calculated to analyze quantitative relationship between the effectiveness of SFFM on water evaporation and the addition rate of SFFM. The calculated half-life increased with the addition rate of SFFM and the confidence of the calculated values of the half-life was high, suggesting that the half-life of effectiveness of SFFM on water evaporation could be described quantitatively and may be helpful for ameliorating application method of SFFM and screening surface-film forming materials in order to improve nitrogen fertilizer use efficiency in flooded rice fields.

Degradation Dynamics of Triadimefon and Difenoconazole Residues in Strawberry and Soil

A field experiment was employed to study the degradation of triadimefon and difenoconazole residues in strawberry and soil. The results showed that the degradation of both the two kinds of pesticides was in accordance with the first order kinetic equation. The half-lives of difenoconazole in strawberry fruit, strawberry stem leaf and soil were 4.09, 8.21 and 13.38 d, respectively; and the half-lives of triadimefon in strawberry fruit, strawberry stem and leaf and soil were 3.38, 5.31 and 15.64 d, respectively. The maximum residue limit （MRL） of difenoconazole in strawberry was recommended as 0.5 mg/kg, and 10% difenoconazole WG and 20% triadimefon EC should be applied four times with a safety interval of 7 d according to the amounts of 100 and 60 g a. i./hm2,respectively.