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Role of osmotic and hydrostatic pressures in bacteriophage genome ejection  [PDF]
Serge G. Lemay,Debabrata Panja,Ian J. Molineux
Quantitative Biology , 2012, DOI: 10.1103/PhysRevE.87.022714
Abstract: A critical step in the bacteriophage life cycle is genome ejection into host bacteria. The ejection process for double-stranded DNA phages has been studied thoroughly \textit{in vitro}, where after triggering with the cellular receptor the genome ejects into a buffer. The experimental data have been interpreted in terms of the decrease in free energy of the densely packed DNA associated with genome ejection. Here we detail a simple model of genome ejection in terms of the hydrostatic and osmotic pressures inside the phage, a bacterium, and a buffer solution/culture medium. We argue that the hydrodynamic flow associated with the water movement from the buffer solution into the phage capsid and further drainage into the bacterial cytoplasm, driven by the osmotic gradient between the bacterial cytoplasm and culture medium, provides an alternative mechanism for phage genome ejection \textit{in vivo}; the mechanism is perfectly consistent with phage genome ejection \textit{in vitro}.
Structural and electronic properties of carbon nanotubes under hydrostatic pressures

Zhang Ying,Cao Jue-Xian,Yang Wei,

中国物理 B , 2008,
Abstract: We studied the structural and electronic properties of carbon nanotubes under hydrostatic pressures based on molecular dynamics simulations and first principles band structure calculations. It is found that carbon nanotubes experience a hard-to-soft transition as external pressure increases. The bulk modulus of soft phase is two orders of magnitude smaller than that of hard phase. The band structure calculations show that band gap of (10, 0) nanotube increases with the increase of pressure at low pressures. Above a critical pressure (5.70GPa), band gap of (10, 0) nanotube drops rapidly and becomes zero at 6.62GPa. Moreover, the calculated charge density shows that a large pressure can induce an {sp}2-to-{sp}3 bonding transition, which is confirmed by recent experiments on deformed carbon nanotubes.
Longitudinal magnetic excitation in KCuCl3 studied by Raman scattering under hydrostatic pressures  [PDF]
H. Kuroe,N. Takami,N. Niwa,T. Sekine,M. Matsumoto,F. Yamada,H. Tanaka,K. Takemura
Physics , 2012, DOI: 10.1088/1742-6596/400/3/032042
Abstract: We measure Raman scattering in an interacting spin-dimer system KCuCl3 under hydrostatic pressures up to 5 GPa mediated by He gas. In the pressure-induced quantum phase, we observe a one-magnon Raman peak, which originates from the longitudinal magnetic excitationand is observable through the second-order exchange interaction Raman process. We report the pressure dependence of the frequency, halfwidth and Raman intensity of this mode.
Signature splitting in $^{173}$W with triaxial particle rotor model  [PDF]
B. Qi,S. Q. Zhang,S. Y. Wang,J. Meng
Physics , 2008, DOI: 10.1142/S0218301309012094
Abstract: A particle rotor model with a quasi-neutron coupled with a triaxially deformed rotor is applied to study signature splitting for bands with intruder orbital $\nu7/2^{+} [633]$ and non-intruder orbital $\nu5/2^{-}[512]$ in $^{173}$W. Excellent agreement with the observed energy spectra has been achieved for both bands. Signature splitting for band $\nu7/2^{+} [633]$, and band $\nu5/2^{-}[512]$ before the onset of signature inversion, is satisfactorily reproduced by introducing the $\gamma$ degree of freedom. The phase and amplitude of signature splitting in band $\nu5/2^{-}[512]$ is attributed to strong competition between $2f_{7/2}$ and $1h_{9/2}$ components. However, the explanation of signature inversion in band $\nu5/2^{-}[512]$ self-consistently is beyond the present one quasi-neutron coupled with a triaxially deformed rotor.
Signature inversion -- manifestation of drift of the rotational axis in triaxial nuclei  [PDF]
Zao-Chun Gao,Y. S. Chen,Yang Sun
Physics , 2006, DOI: 10.1016/j.physletb.2006.01.033
Abstract: A possible scheme of realizing shell model calculations for heavy nuclei is based on a deformed basis and the projection technique. Here we present a new development for odd-odd nuclei, in which one starts with triaxially-deformed multi-quasi-particle configurations, builds the shell-model space through exact three-dimensional angular-momentum-projection, and diagonalizes a two-body Hamiltonian in this space. The model enables us to study the old problem of signature inversion from a different view. With an excellent reproduction of the experimental data in the mass-130 region, the results tend to interpret the phenomenon as a manifestation of dynamical drift of the rotational axis with presence of axial asymmetry in these nuclei.
Transition pressures and enthalpy barriers for the cd->beta-tin transition in Si and Ge under non-hydrostatic conditions  [PDF]
Katalin Gaal-Nagy,Dieter Strauch
Physics , 2005, DOI: 10.1103/PhysRevB.73.134101
Abstract: We present an ab-initio study of the phase transition cd->beta-tin in Si and Ge under hydrostatic and non-hydrostatic pressure. For this purpose we have developed a new method to calculate the influence of non-hydrostatic pressure components not only on the transition pressure but also on the enthalpy barriers between the phases. We find good agreement with available experimental and other theoretical data. The calculations have been performed using the plane-wave pseudopotential approach to the density-functional theory within the local-density and the generalized-gradient approximation implemented in VASP.

Qin Ling Tang Guoqing Ruan Kangcheng,

微生物学报 , 1996,
Abstract: The effect of hydrostatic pressure on the death of E. coli was studied in this paper. The results indicated that E. coli could be killed by hydrostatic pressure above 800 bar. At 2300 bar E.coli was totally killed in 30 minutes. The time course of E. coli death induced by pressure indicated that the most E. coli was killed in the first 10 minutes after the pressure was applied. It was also found that the lower temperature favored killing E. coli under pressure.
Hydrostatic pressures dependence of superconductivity in PrO0.5F0.5BiS2 superconductor  [PDF]
G. Kalai Selvan,M. Kanagaraj,Rajveer Jha,V. P. S. Awana,S. Arumugam
Physics , 2013,
Abstract: In this communication, we report the temperature dependence (3 to 300K) of the electrical resistivity of BiS2 based layered PrO0.5F0.5BiS2 superconductor at ambient and hydrostatic pressure of up to 3GPa. It is observed that Tc increases with pressure at the rate of dTc/dP=0.45/GPa for PrO0.5F0.5BiS2 compound. It is envisaged that one may increase the Superconducting transition temperature (Tc) of recently discovered PrO0.5F0.5BiS2 superconductor by applying hydrostatic external or internal chemical pressure via suitable on site substitutions.

CHEN Weizhong,YU Hongdan,WANG Xiaoquan,JIA Shanpo,HAO Qingze,HUANG Sheng,

岩石力学与工程学报 , 2009,
Abstract: In order to study the long term mechanical properties,the double-linkage triaxial testing machine for hydro-mechanical coupling in soft rock is developed. This machine is particularly applicable to study the rheological characteristics of soft rock and hard soil under various stress conditions. Using the technology of servo-controlled,ball screw and hydraulic pressure,this machine can automatically stabilize voltage and record stress-strain variation curve and temperature duration curve. In addition to the function of ordinary triaxial device,because of the unique design form of this machine,it not only can implement the mechanical tests simultaneously of two samples with same axial pressure,different confining pressures and same water pressure but also execute confining pressure control,pore water pressure control and its survey,etc.. The service condition shows that it is a convenient machine with complete functions,simple structure,good stability and high precision.
Ultrasonic measurements of single-crystal gold under hydrostatic pressures up to 8 GPa in a Kawai-type multi-anvil apparatus
MaoShuang Song,Akira Yoneda,Eiji Ito
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0240-y
Abstract: Ultrasonic measurements were conducted on single-crystal gold at ambient condition and hydrostatic pressures up to 8 GPa at room temperature in a Kawai-type multi-anvil apparatus. The P-wave velocities measured at high pressures were in good agreement with Daniels and Smith’s ultrasonic study. The three independent elastic constants of gold at ambient condition were determined to be C 11=192.7 GPa, C 12=162.9 GPa, and C 44=42.4 GPa. On the basis of an analysis of previous elastic data and the present ultrasonic data, the pressure derivatives of three elastic constants were estimated to be C′11 = 7.12, C′12 = 6.24, and C′44 = 1.82. The calculated values of isothermal bulk modulus (K T0) and its pressure derivatives (K′T0) are K T0 = 166.44 GPa and K′T0 = 6.56. This indicates that Anderson et al.’s model of equation of state of gold might underestimates pressure about 1 GPa at pressure around 23 GPa and ambient temperature. Our results explained the discrepancies among the models of equation of state of gold proposed previously.
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