Density functional scheme for calculating the pair density

The density functional scheme for calculating the pair density is presented by means of the constrained-search technique. The resultant single-particle equation takes the form of the modified Hartree-Fock equation which contains the kinetic contribution of the exchange-correlation energy functional as the correlation potential. The practical form of the kinetic contribution is also proposed with the aid of the scaling relations of the kinetic energy functionals.Comment: 5 page

Management approach for recurrent spontaneous pneumothorax in consecutive pregnancies based on clinical and radiographic findings

OBJECTIVE: To describe management and clinical features observed in a patient's seven spontaneous pneumothoraces that developed during two consecutive pregnancies involving both hemithoraces. MATERIALS AND METHODS: A 21 year old former smoker developed three spontaneous left pneumothoraces in the index pregnancy, having already experienced four right pneumothorax events in a prior pregnancy at age 19. RESULTS: Chest tubes were required in several (but not all) hospitalizations during these two pregnancies. Following her fourth right pneumothorax, thoracoscopic excision of right apical lung blebs and mechanical pleurodesis was performed. The series of left pneumothoraces culminated in mini-thoracotomy and thoracoscopically directed mechanical pleurodesis. For both pregnancies unassisted vaginal delivery was performed with no adverse perinatal sequelae. With the exception of multiple pneumothoraces, there were no additional pregnancy complications. CONCLUSION: Spontaneous pneumothorax in pregnancy is believed to be a rare phenomenon, yet the exact incidence is unknown. Here we present the first known case of multiple spontaneous pneumothoraces in two consecutive pregnancies involving both hemithoraces. Clinical management coordinated with obstetrics and surgical teams facilitated a satisfactory outcome for both pregnancies. The diagnosis of pneumothorax should be contemplated in any pregnant patient with dyspnea and chest pain, followed by radiographic confirmation

Atomic structures beyond the spherical approximation along with PNC as conjectured explanations to Urbach tailing in neutral isolated ytterbium

In this paper, we try to give an explanation to the spectacular Urbach tailing associated to ytterbium. This rare earth element performs odd spectra due to its 5f-electron shell configuration and complexity of its transition dynamics within band structure. Ytterbium particular forbidden band alteration has been associated to two major inconsistencies: calculating atomic single-particle wave functions and spectra without taking into account the non-spherical effects and neglecting the high parity non conserving (PNC) amplitudes in ytterbium absorption-emission spectra. The actual band structure calculation has been achieved within the Hartree-Fock-Slater approximation. It led to a noticeable blue shift resulting in narrowing the forbidden band from upper edge. Parity non conserving (PNC) amplitudes were also proposed as an explanation to width reduction from both upper and lower band edges. The relative extent of these reductions seems to coincide with Urbach tailing dimensions recorded in recent studies