为什么鸡蛋洗干净了反而容易坏

记得暑假的一天，我闲在家里没事做,看到冰箱里面的鸡蛋脏兮兮的,就一个一个地用清水洗干净再放到冰箱里.结果没几天妈妈发现鸡蛋全坏了.……

Existence of Tensor Glueball ξ（2230） and Its Mass, Spin, and Decay Width

In order to solve the current experimental controversy on the existence of the tensor glueball ξ(2230), we examine whether the conclusion from Seth's experimental measurement, which rejects existence of ξ(2230), is reliable.We claim that the non-observation of the resonance structure by Seth is not a sound ground for rejecting the existence of ξ(2230) but it may just indicate that ξ(2230) has a broad width. We also study the tensor glueball properties: the mass, spin, and decay width. Our theoretical predictions of the mass and the spin of the ξ(2230) using QCD sum rule are about 2.23 GeV and J = 2, respectively. Our theoretical results also evidently show that the ξ(2230) must have a total decay width of about 100 MeV, which is much broader than the reported 20 MeV but a small partial decay width of 2 MeV into pp decay channel.

Science Letters; In-situ synthesis and luminescence properties of titanium oxide gels containing 1,10-phenanthroline europium(Ⅲ) complex

It is difficult to directly dope europium complexes in gel because the excessive water or high acidic condition may lead to their decomposition. We prepared a novel homogeneous TiO2 gel containing Eu-phen complexes by using an in-situ synthesis method. The formation of Eu-phen complexes in sol-gel derived TiO2 was confirmed by luminescence excitation spectra. The effects of temperature and aging time on in-situ synthesis are discussed. The luminescence spectra of gel containing europium complexes were also compared with the pure Eu-phen complexes.

Sol-Gel Synthesis and Structure-Property Relations in Nd4-xCs2（1＋x）Fe5-xZnxO14＋δ（0≤x≤1.0） Oxide Systems

Synthesis of composite oxides in the series Nd4-xCs2（1＋x）Fe5-xZnxO14＋δ（0≤x≤1.0） （B1-B5： x= 0.0, 0.25, 0.5, 0.75, 1.0） is performed by sol-gel method via nitrate-acetate precursor route. Analysis of the powder x-ray diffraction （XRD） patterns show tetragonal unit cell with lattice parameters a = 8.6545, 8.2520, 7.7645, 9.8952, 8.2863 A; b = 8.9800, 11.5788, 15.6305, 8.4766, 11.6465 A in B1-B5, respectively. The average crystallite sizes in the samples are found to be in the range 69.56-119.48 A. Energy dispersive analysis of x-rays （EDAX） result shows the presence of Fe, Nd, Cs and O, and Fe, Nd, Zn, Cs and O in B 1 （x=0） and B2（x=0.25）-B5（x= 1.0）, respectively. The IR results at 300 K show the presence of octahedral [NdO6/2]^3- （asymmetric stretch： 410-416 cml） and [FeO6/2]^3-（symmetric stretch： 562-572 cm^-1） units in the samples. Observed magnetic moments versus magnetic field plots in the range -10 kG to ＋10 kG exhibit hysteresis loops with average magnetic susceptibility values in the range 3.46 × 10^-5 -7.05 × 10^-5 emu/gG in B1-B5 shows fairly strong ferromagnetic nature of the samples. The observed EPR lineshapes at 300 and 77 K with giso=2.01-2.03 and giso=2.01-2.03, respectively is ascribed to the octahedral [FeO6/2]^3- coordination of Fe^3＋ （3d^5） ion. The optical absorption spectra show the transition of ^4I9/2→^4F7/2→^ 4S3/2 （750 nm） of optically active Nd^3＋ ions in samples.

Clinicopathological and immunohistochemical features of pilomyxoid astrocytoma: a report of six cases

Objective： The aim of this study was to study the clinicopathological and immunohistochemical features of pilo- myxoid astrocytoma （PMA）. Methods： The clinical and pathologic features in six cases of PMA were analyzed. Immunohisto- chemical staining for glial fibrillary acidic protein （GFAP）, synaptophysin （Syn）, Chromogranin A （CgA）, cytokeratin （AEI/AE3）, epithelial membrane antigen （EMA） and Ki67 was performed on paraffin-embedded sections. Results： Among the six cases, five occurred in female patients, one was male, the age at diagnosis ranged from 2 to 15 years. Four cases were located in the hypothalamic area and optic pathway, one case in the third ventricle, and one case in left parietal lobe. On imaging, PMAs often appears as well-circumscribed mass. Microscopically, the tumor was composed of monomorphous bipolar （piloid） cells setting in a prominent myxoid background with an angiocentric radiating growth pattern in some areas. PMA lacked biphasic pattern, Rosenthal fibers and eosinophilic granular bodies which were usually typical in a classic pilocytic astrocytoma （PA）. Immunohistochemcal study showed that the tumor cells were diffusely positive for GFAP. Syn positive staining was observed in one case. The Ki67 labeling index measured less than 5%. Conclusion： PMA is a distinct aggressive variant of pilocytic astrocytoma with special histological and immunohistochemical features. It is typically a rare tumor of early childhood. Im- munohistochemical staining for GFAP and Syn is helpful in differential diagnosis.

A novel method for distinguishing fog and haze based on PM2.5, visibility, and relative humidity

Haze and fog are both low visibility events, but with different physical properties. Haze is caused by the increase of aerosol loading or the hygroscopic growth of aerosol at high relative humidity, whereas visibility degradation in fog is due to the light scattering of fog droplets, which are transited from aerosols via activation. Based on the difference of physical properties between haze and fog, this study presents a novel method to distinguish haze and fog using real time measurements of PM2.5, visibility, and relative humidity. In this method, a criterion can be developed based on the local historical data of particle number size distributions and aerosol hygroscopicity. Low visibility events can be classified into haze and fog according to this criterion.

Changes of serum Tau, GFAP, TNF-α and malonaldehyde after blast-related traumatic brain injury

Objective： To determine the changes of serum Tau protein, glial fibrillary acidic protein （GFAP）, tumor necrosis factor alpha （TNF-α）, and malonaldehyde （MDA） in rats after blast-related traumatic brain injury （BTBI） and to provide relative information for further studies on BTBI mechanism and seek specific biomarkers for BTBI. Methods： Ninety male Sprague-Dawley rats were randomly assigned into three groups： control group, moderate blast injury group, and severe blast injury group （n=30 for each）. Rats in the moderate and severe blast injury groups were respectively exposed to corresponding levels of BTBI. After explosion, serum levels of Tau, GFAP, TNF-α, and MDA in each group were determined by Elisa assay at different time points after injury （8 h, 24 h, 3 d, and 6 d）. The extent of brain damage was detected by Nissl staining and TUNEL assay. Results： Serum levels of Tau and GFAP rapidly increased and reached the peak at 24 h after either moderate or severe blast injury. All the values were significantly higher than control group at all time points （P〈0.05）. Serum TNF-α level of both injury groups peaked at 8 h after BTBI and stayed significantly higher than control group at all time points （P〈0.05）. Serum MDA of two injury groups began to significantly increase at 3 d and the level stayed significantly higher than control group until 6 d （P〈0.05）. Moreover, unlike the other biomarkers, serum MDA of severe blast injury group was significantly higher than moderate blast injury group at 6 d （P〈0.05）. Conclusion： The changes of serum Tau, GFAP, and TNF-α showed a good sensitivity at the acute phase after BTBI （within 24 h）. However, their specificity and correlation with the extent of injury were limited in this experiment. Moreover, although the change of serum MDA showed a poor sensitivity and specificity to the diagnosis of BTBI during the first few days, it can reflect the injury degree at 6 d after injury. Therefore, further studies are needed to improve the methods of detecting more serum markers and investigate the significance of multiple markers in diagnosing BTBI.

Rubbery neat carbon aerogels

Polymeric elastomers possess unique elastic mechanical properties that set them apart from other materials,and enable wide applications in a large variety of products such as elastic films,foams and tires.The polymer chains tend to be coil-like due to thermal fluctuation but can also be straightened by external forces,leading to large reversible deformations.

Flexible electrostatic hydrogels from marine organism for nitric oxide-enhanced photodynamic therapy against multidrug-resistant bacterial infection

The abuse of antibiotics in treating microbial infections has led to the emergence and prevalence of drugresistant bacteria.Thus,the development of novel antibacterial materials is attracting increasing attention.Here,a series of flexible electrostatic hydrogels with excellent antibacterial ability were constructed using a mixture of nitric oxide(NO)-releasing nitrated chitosan(CSNO)and mesotetra(4-carboxyphenyl)porphine(TCPP)with salmon sperm DNA(ssDNA)solution.When cultured with gram-negative bacteria under solar simulator irradiation,TCPP-CSNO_(m)ssDNA_(n) hydrogels released reactive oxygen species(ROS)and NO to produce peroxynitrite ions(ONOO^(−)).ONOO−is efficient at killing bacteria,thereby improving the antimicrobial ability of photodynamic therapy against gram-negative bacteria.The hydrogels exhibited powerful antibacterial activity in vivo when used to treat skin infections caused by drugresistant bacteria,making them a promising candidate for clinical applications.A string of antibacterial hydrogels that release ROS and NO synergistically can bring new possibilities for effectively killing drug-resistant bacteria and be of great value in anti-infection wound dressings and other applications.