Jednadžbe stanja, energije vezanja, volumni moduli i Gruneisenove konstante 3d, 4d i 5d prijelaznih metala

A model pseudopotential, depending on an effective core radius but otherwise parameter-free, is proposed to study the equation of state by incorporating the s-d hybridization effects. A new criterion for the selection of the exchange and correlation effects is also put forward. The equations of state for Cu, Ta, Mo, W and Pt have been studied up to the pressure of 1000 GPa. The binding energy, pressure, bulk modulus and frequency-independent Grüneisen constant as functions of volume for transition metals are calculated. The theoretical results are compared with available experimental results. The successful application to 27 metals has confirmed our formalism.Uvodimo model potencijala koji ovisi o polumjeru efektivne sredice a ne o drugim parametrima radi proučavanja jednadžbe stanja s uključenim s-d efektima hibridizacije. Postavljamo također nov kriterij za odabir efekata izmjena i korelacija. Proučavamo jednadžbu stanja Cu, Ta, Mo, W i Pt za tlakove do 1000 GPa. Izračunavamo energije vezanja, tlak, volumne module i frekventno-neovisne Gruneisenove konstante. Ishodi računa uspoređuju se s eksperimentalnima za sve poznate podatke. Uspješna primjena našeg formalizma za 27 metala ga potvrđuje

Analysis of ectopic pregnancy at a tertiary care hospital: one year study

Background: Ectopic gestation is the leading cause of maternal mortality and morbidity in first trimester and is a major cause of reduced child bearing potential. The aims of our study were to understand the clinical profile, risk factors, sites and management modalities of ectopic pregnancy at tertiary care hospital.Methods: This is a retrospective study carried out for one year at the department of Obstetrics and Gynaecology of our institute. Data of the women admitted for management of ectopic pregnancy during January to December, 2010 was collected and analysed.Results: The proportion of ectopic pregnancy was 0.7 % at our institute. Majority of women 45(83.2%) were between the age group of 21-30 years. Pelvic inflammatory disease (PID) contributed to ectopic pregnancy in 16(29.6%) women. The most common symptom was lower abdominal pain, in 50(92.6%) women. Marked pallor was present in 25(46.3%) women and 38(70.4%) women had cervical motion tenderness. Out of all women, 10(18.5%), 18(33.3%) and 26(48.1%) women were managed successfully with methotrexate, laparoscopy and laparotomy respectively. The success rate was 83.3%, 90% and 100% with methotrexate, laparoscopy and laparotomy respectively. Blood and blood products were given to 25(46.3%) women. Conclusion: Ectopic pregnancy is a growing problem of reproductive age group. Women should be encouraged regarding early reporting of missed periods and made aware of complications of ectopic pregnancy and necessity of seeking urgent medical help as early as possible so that early diagnosis and prompt conservative surgical or medical management of ectopic pregnancy can be done

Microseismicity and permeability enhancement of hydrogeologic structures during massive fluid injections into granite at 3 km depth at the Soultz HDR site

A high-rate injection of 20 000 m3 of water into granite between 2.8 and 3.4 km depth at the Soultz hot dry rock (HDR) test site in France in 1993 September led to a 200-fold increase in borehole transmissivity and produced a subvertical cloud of microseismicity of dimensions 0.5 km wide, 1.2 km long, 1.5 km high and oriented 25°NW. The resulting data set is unusually complete and well suited to studying permeability creation/enhancement processes in crystalline rock and the utility of microseismic data for revealing them. Although the microseismic cloud defined using joint hypocentre determination (JHD) locations was diffuse and showed little structure, application of the collapsing method showed it to be composed largely of discrete tubes and planes that propagated coherently. One prominent structure that extended 350 m downwards from the vicinity of a flow inlet early in the injection and that appears to contain a major flow path was subjected to detailed investigation to establish its hydrogeologic nature and the mechanisms underpinning its inferred permeability enhancement. High-resolution microseismic mapping techniques (i.e. multiplets and clustering) showed it to be a subvertical, NNW-SSE striking, fracture zone of width 10-20 m. The strike and scale of the structure identifies it as a member of a family of hydrothermally altered, cataclastic shear structures that constitute the primary permeable paths for fluid migration within the rock mass, both under ambient and forced fluid flow conditions. The microseismicity occurred on subvertical, small-scale fractures within the cataclastic shear zone whose azimuths scatter within 22° of parallel to the parent structure. Although the structure is likely to have been naturally permeable to some degree, its permeability appears to have been significantly enhanced as a consequence of the injection. The most likely mechanism of permeability enhancement, which is in accord with the strong preference for the microseismicity to grow downwards, involves strike-slip shearing, which produced the opening of vertical tubes at along-strike jogs in the fault (the so-called Hill mesh). Seismic moment release averaged over the structure suggests shear displacements of at least 0.3 mm occurred, which are sufficient to generate aperture changes that are hydraulically significant. The preponderance of discrete structures within the microseismic cloud after collapsing suggests that significant flow and permeability enhancement (i.e. stimulation) within the rock mass is largely confined to the interiors of shear zones that appear to have a spacing of approximately 100

Chromosomal radiosensitivity in head and neck cancer patients: evidence for genetic predisposition?

The association between chromosomal radiosensitivity and genetic predisposition to head and neck cancer was investigated in this study. In all, 101 head and neck cancer patients and 75 healthy control individuals were included in the study. The G2 assay was used to measure chromosomal radiosensitivity. The results demonstrated that head and neck cancer patients had a statistically higher number of radiation-induced chromatid breaks than controls, with mean values of 1.23 and 1.10 breaks per cell, respectively (P<0.001). Using the 90th percentile of the G2 scores of the healthy individuals as a cutoff value for chromosomal radiosensitivity, 26% of the cancer patients were radiosensitive compared with 9% of the healthy controls (P=0.008). The mean number of radiation-induced chromatid breaks and the proportion of radiosensitive individuals were highest for oral cavity cancer patients (1.26 breaks per cell, 38%) and pharynx cancer patients (1.27 breaks per cell, 35%). The difference between patients and controls was most pronounced in the lower age group (⩽50 years, 1.32 breaks per cell, 38%) and in the non- and light smoking patient group (⩽10 pack-years, 1.28 breaks per cell, 46%). In conclusion, enhanced chromosomal radiosensitivity is a marker of genetic predisposition to head and neck cancer, and the genetic contribution is highest for oral cavity and pharynx cancer patients and for early onset and non- and light smoking patients

DNA repair capacity as a possible biomarker of breast cancer risk in female BRCA1 mutation carriers

The BRCA1 gene product helps to maintain genomic integrity through its participation in the cellular response to DNA damage: specifically, the repair of double-stranded DNA breaks. An impaired cellular response to DNA damage is a plausible mechanism whereby BRCA1 mutation carriers are at increased risk of breast cancer. Hence, an individual's capacity to repair DNA may serve as a useful biomarker of breast cancer risk. The overall aim of the current study was to identify a biomarker of DNA repair capacity that could distinguish between BRCA1 mutation carriers and non-carriers. DNA repair capacity was assessed using three validated assays: the single-cell alkaline gel electrophoresis (comet) assay, the micronucleus test, and the enumeration of γ-H2AX nuclear foci. DNA repair capacity of peripheral blood lymphocytes from 25 cancer-free female heterozygous BRCA1 mutation carriers and 25 non-carrier controls was assessed at baseline and following cell exposure to γ – irradiation (2 Gy). We found no significant differences in the mean tail moment, in the number of micronuclei or in the number of γ-H2AX nuclear foci between the carriers and non-carriers at baseline, and following γ-irradiation. These data suggest that these assays are not likely to be useful in the identification of women at a high risk for breast cancer

Accelerated functional brain aging in pre-clinical familial Alzheimer’s disease

Resting state functional connectivity (rs-fMRI) is impaired early in persons who subsequently develop Alzheimer’s disease (AD) dementia. This impairment may be leveraged to aid investigation of the pre-clinical phase of AD. We developed a model that predicts brain age from resting state (rs)-fMRI data, and assessed whether genetic determinants of AD, as well as beta-amyloid (Aβ) pathology, can accelerate brain aging. Using data from 1340 cognitively unimpaired participants between 18–94 years of age from multiple sites, we showed that topological properties of graphs constructed from rs-fMRI can predict chronological age across the lifespan. Application of our predictive model to the context of pre-clinical AD revealed that the pre-symptomatic phase of autosomal dominant AD includes acceleration of functional brain aging. This association was stronger in individuals having significant Aβ pathology

Spontaneous and radiation-induced chromosomal instability and persistence of chromosome aberrations after radiotherapy in lymphocytes from prostate cancer patients

The aim of the study was to compare the spontaneous and ex vivo radiation-induced chromosomal damage in lymphocytes of untreated prostate cancer patients and age-matched healthy donors, and to evaluate the chromosomal damage, induced by radiotherapy, and its persistence. Blood samples from 102 prostate cancer patients were obtained before radiotherapy to investigate the excess acentric fragments and dicentric chromosomes. In addition, in a subgroup of ten patients, simple exchanges in chromosomes 2 and 4 were evaluated by fluorescent in situ hybridization (FISH), before the onset of therapy, in the middle and at the end of therapy, and 1 year later. Data were compared to blood samples from ten age-matched healthy donors. We found that spontaneous yields of acentric chromosome fragments and simple exchanges were significantly increased in lymphocytes of patients before onset of therapy, indicating chromosomal instability in these patients. Ex vivo radiation-induced aberrations were not significantly increased, indicating proficient repair of radiation-induced DNA double-strand breaks in lymphocytes of these patients. As expected, the yields of dicentric and acentric chromosomes, and the partial yields of simple exchanges, were increased after the onset of therapy. Surprisingly, yields after 1 year were comparable to those directly after radiotherapy, indicating persistence of chromosomal instability over this time. Our results indicate that prostate cancer patients are characterized by increased spontaneous chromosomal instability. This instability seems to result from defects other than a deficient repair of radiation-induced DNA double-strand breaks. Radiotherapy-induced chromosomal damage persists 1 year after treatment