Correlation of structural order, anomalous density, and hydrogen bonding network of liquid water

We use extensive molecular dynamics simulations employing different state-of-the-art force fields to find a common framework for comparing structural orders and density anomalies as obtained from different water models. It is found that the average number of hydrogen bonds correlates well with various order parameters as well as the temperature of maximum densities across the different models, unifying apparently disparate results from different models and emphasizing the importance of hydrogen bonding in determining anomalous properties and the structure of water. A deeper insight into the hydrogen bond network of water reveals that the solvation shell of a water molecule can be defined by considering only those neighbors that are hydrogen-bonded to it. On the basis of this view, the origin of the appearance of a non-tetrahedral peak at a higher temperature in the distribution of tetrahedral order parameters has been explained. It is found that a neighbor that is hydrogen-bonded to the central molecule is tetrahedrally coordinated even at higher temperatures. The non-tetrahedral peak at a higher temperature arises due to the strained orientation of the neighbors that are non-hydrogen-bonded to the central molecule. With the new definition of the solvation shell, liquid water can be viewed as an instantaneously changing random hydrogen-bonded network consisting of differently coordinated hydrogen-bonded molecules with their distinct solvation shells. The variation of the composition of these hydrogen-bonded molecules against temperature accounts for the density anomaly without introducing the concept of large-scale structural polyamorphism in water.

Gentamicin in combination with ascorbic acid regulates the severity of Staphylococcus aureus infection-induced septic arthritis in mice

To study the effects of gentamicin in combination with ascorbic acid on septic arthritis, mice were infected with Staphylococcus aureus (S. aureus) and treated with gentamicin, which was given at 5 mg/kg after 24 h of infection, followed by ascorbic acid, given at 20 mg/kg body weight after 2 h of gentamicin treatment. Mice were sacrificed at 3, 9, 15 days post-infection (dpi). Combined treatment of infected mice with gentamicin and ascorbic acid eradicated the bacteria from the blood, spleen and synovial tissue and showed a significant gross reduction in arthritis, reduced serum levels of tumour necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). S. aureus-infected mice have demonstrated the disturbed antioxidant status measured in terms of cellular antioxidants like reduced glutathione and antioxidant enzymes such as superoxide dismutase (SOD) and catalase. The same were ameliorated when the animals were co-treated with gentamicin along with ascorbic acid.

Fall frequency and risk assessment in early Parkinson's disease

BACKGROUND

We sought to define the frequency of falls in early PD and assess potential risk factors for falls in this population.

METHODS

We analyzed the data from two randomized, placebo controlled trials (NET-PD FS1 and FS-TOO) of 413 individuals with early PD over 18 months of follow-up in FS1 and 12 months in FS-TOO. Falls were defined as any report of falls on the UPDRS or the adverse event log. We assessed the frequency of falls overall and by age. The relationship between prespecified fall risk markers and the probability of falling was assessed using logistic and multiple logistic regression. A hurdle Poisson model was used to jointly model the probability of remaining fall-free and the number of falls.

RESULTS

During the follow-up period, 23% of participants fell, and 11% were habitual fallers. In a multiple logistic regression model, age, baseline UPDRS Falling score, and baseline PDQ-39 scores were associated with subsequent fall risk (p < 0.001). Similarly, in a hurdle Poisson regression model, age, baseline UPDRS falling item, and baseline PDQ-39 were all significantly related to the probability of falling, but only UPDRS falling >0 was associated with the number of falls.

CONCLUSION

Falls are frequent and are associated with impaired quality of life, even in early PD. Current standard rating scales do not sufficiently explain future fall risk in the absence of a prior fall history. New assessment methods for falls and postural instability are required to better evaluate this important problem in clinical trials and clinical practice.

Prognostic markers in AIDS-related cryptococcal meningitis

OBJECTIVE

Despite the advent and expanding access to antiretroviral therapy, HIV-associated cryptococcal meningitis (CM) remains a significant cause of mortality and morbidity amongst individuals with this infection in resource-limited settings.

METHODS

We prospectively studied the clinical, biochemical and mycological parameters of 30 HIV patients diagnosed with cryptococcal meningitis at our centre over a period of 6 months with a view to identify prognostic factors predictive of poor outcome.

RESULTS

Our study documented a mortality rate of 36.7%. Age, sex and previous diagnosis of HIV had no bearing on the survival outcome of patients. The study identified several poor prognostic factors including low GCS score, papilledema, elevated CSF opening pressure (>250 mm of H2O) and lack of regular HIV care in those with a prior diagnosis of HIV. CSF pleocytosis was significantly higher in the mortality group.

CONCLUSION

There have been relatively few attempts to focus on poor prognostic markers associated with AIDS related Cryptococcal meningitis in Asian patients. Our study highlights how simple bedside clinical tools like ophthalmoscopy and CSF manometry can help in risk stratification in this group of patients.

Laparoscopic resection for recurrent Crohn's disease: safety, feasibility and short-term outcomes

AIM

The safety, feasibility and short-term outcomes of laparoscopic resection were assessed in patients with recurrent ileocolic Crohn's disease.

METHOD

A consecutive series of patients was identified from a prospectively collated database. Data included patient demographics, previous medical and surgical treatment, operative details and postoperative course. Data from the original index open operation were collected retrospectively by review of the case notes.

RESULTS

Between 2005 and 2009, 27 patients [21 women, mean (range) age 31 years (16-51 years)] underwent laparoscopic resection for recurrent ileocolic Crohn's disease. All had histologically confirmed recurrent disease at the ileocolic anastomosis. Five (18.5%) patients required extended resection for Crohn's colitis, three (11.1%) had fistulating disease and one (3.4%) patient had a psoas abscess. The median (range) operative time was 110 min (70-170 min) with a conversion rate of two (7.4%) of 27 patients. The length of stay was 4 days (2-7 days) with time to return to work or full activity of 3.5 weeks (2-7 weeks).

CONCLUSION

Laparoscopic resection of recurrent ileocolic Crohn's disease is safe, feasible and associated with short-term benefits.

High-precision half-life measurement for the superallowed β+ emitter ²⁶Al(m)

A high-precision half-life measurement for the superallowed β+ emitter 26Al(m) was performed at the TRIUMF-ISAC radioactive ion beam facility yielding T 1/2 6346.54 ± 0.46(stat) ± 0.60 (syst) ms, consistent with, but 2.5 times more precise than, the previous world average. The 26Al(m) half-life and ft value, 3037.53(61) s, are now the most precisely determined for any superallowed β decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected Ft value for (26)Al(m), 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi β-decay studies used to test the conserved vector current hypothesis and determine the V(ud) element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

Robust Bayesian Analysis of Heavy-tailed Stochastic Volatility Models using Scale Mixtures of Normal Distributions

A Bayesian analysis of stochastic volatility (SV) models using the class of symmetric scale mixtures of normal (SMN) distributions is considered. In the face of non-normality, this provides an appealing robust alternative to the routine use of the normal distribution. Specific distributions examined include the normal, student-t, slash and the variance gamma distributions. Using a Bayesian paradigm, an efficient Markov chain Monte Carlo (MCMC) algorithm is introduced for parameter estimation. Moreover, the mixing parameters obtained as a by-product of the scale mixture representation can be used to identify outliers. The methods developed are applied to analyze daily stock returns data on S&P500 index. Bayesian model selection criteria as well as out-of- sample forecasting results reveal that the SV models based on heavy-tailed SMN distributions provide significant improvement in model fit as well as prediction to the S&P500 index data over the usual normal model.

New features of shape coexistence in ;{152}Sm

Excited states in ;{152}Sm have been investigated with the ;{152}Sm(n,n;{'}gamma) reaction. The lowest four negative-parity band structures have been characterized in detail with respect to their absolute decay properties. Specifically, a new K;{pi} = 0;{-} band has been assigned with its 1;{-} band head at 1681 keV. This newly observed band has a remarkable similarity in its E1 transition rates for decay to the first excited K;{pi} = 0;{+} band at 684 keV to the lowest K;{pi} = 0;{-} band and its decay to the ground-state band. Based on these decay properties, as well as energy considerations, this new band is assigned as a K;{pi} = 0;{-} octupole excitation based on the K;{pi} = 0_{2};{+} state. An emerging pattern of repeating excitations built on the 0_{2};{+} level similar to those built on the ground state may indicate that ;{152}Sm is a complex example of shape coexistence rather than a critical point nucleus.

Utility of abdominal ultrasonography in HIV patients

INTRODUCTION

Various diseases associated with human immunodeficiency virus (HIV) infection are often difficult to diagnose. A poor immune response, atypical presentations and opportunistic pathologies all contribute to this difficulty. We tried to evaluate the utility of routine abdominal ultrasonography (US) in new and follow-up HIV cases, and compared the results among those with a clinical need for US and those where US was performed as a routine screening.

METHODS

150 consecutive seropositive patients were subdivided into four groups depending on the necessity of abdominal US on the initial workup, i.e. Group A (38 patients) or B (112 patients), and whether they were newly-diagnosed HIV patients or follow-up patients, i.e. Group X (62 patients) or Y (88 patients), giving us subgroups, AX (22 patients), AY (16 patients), BX (40 patients) and BY (72 patients).

RESULTS

The prevalence of significant US findings was higher in those with CD4 less than 200 cells/ml (77.8 percent) compared to those with CD4 200-500 cells/ml and CD4 more than 500 cells/ml (65.5 percent and 37 percent, respectively). 24 out of 38 patients with clinical indications and 71 out of 112 patients without any obvious clinical need for US, had positive findings on US, the majority of which had a major therapeutic impact.

CONCLUSION

We conclude that abdominal US is a simple and cost-effective tool in resource-poor countries like India, where HIV care is becoming more and more important.

Correlations between c-erbβ-2 Oncogene Amplification and the Expression of Its mRNA and Protein in Human Breast Carcinomas

Nineteen human breast tumours were analysed for c-erb beta-2 gene amplification, the over-expression of its mRNA and the production of its protein residue by southern blot, northern blot and western blot technique respectively. Protein expression was also assessed by immunohistochemistry on paraffin sections, c-erb beta-2 gene amplification was found in 6 of 19 (31%) tumours. Over-expression of c-erb beta-2 mRNA was found in 7 of 19 (37%) tumours. Expression of the 185 kd c-erb beta-2 protein product was detected in 3 of 19 (16%) tumours by western blotting and in 5 of 19 (26%) by immunohistochemistry. In only 4 tumours with an amplified c-erb beta-2 gene was there a clear association between all three parameters. In view of the conflicting reports in the literature concerning c-erb beta-2 gene amplification or protein over-expression (assessed by western blot or immunohistochemistry) and prognosis of breast cancer, studies in which these parameters are correlated individually with prognosis in the same group of patients are needed.